WEEK 1 - CHAPTER 1: EVOLUTION OF A
SCIENCE
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Psychology: scientific study of mind and behaviour
○ Mind: private inner experience of perceptions, thoughts, memories, feelings
○ Behaviour: observable actions of human beings + nonhuman animals
■ Overt and covert
PSYCHOLOGY’S ANCESTORS: THE GREAT
PHILOSOPHERS
HOW DO YOUNG CHILDREN LEARN ABOUT THE WORLD?
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Nativism: philosophical view that certain kinds of knowledge are innate/inborn
○ Plato was a nativist; believed certain kinds of knowledge are innate
PHILOSOPHICAL EMPIRICISM
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Philosophical view that all knowledge is acquired through experience
○ Aristotle believed that the mind is a blank state (tabula rasa) on which experiences are written
■ We are born blank; the environment is what shapes us
LINKING THE MIND TO THE BRAIN - THE FRENCH CONNECTION
RENÉ DESCARTES (1595-1650)
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French philosopher who argued for dualism of a mind and body
Believed that the physical body was a container for the nonphysical thing (i.e. mind)
THOMAS HOBBES (1588-1679)
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Argued against Descartes; said the mind is what the brain does - mind and body are integrated
FRANZ JOSEPH GALL (1758-1828)
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Phrenology: now defunct theory that specific mental abilities + characteristics are located in specific
regions of the brain
○ Eg bump on the head indicates aggression
PIERRE FLOURENS (1794-1867)
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Surgically removed brain pieces
Argued against Gall’s methods
PAUL BROCA (1824-1880)
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Had crucial insight that damage to a specific part of the brain impaired a specific mental function => brain
and mind are closely linked
Studied brain-damaged PTs to link localization to ability
○ Did autopsy on his servant w/ aphasia; found lesions to left hemisphere (Broca’s area), production
of speech
STRUCTURALISM: A FIRST STEP TOWARD THE SCIENTIFIC METHOD
HERMANN VON HELMHOLTZ (1821-1894)
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Studied human reaction time; estimated length of nerve impulse
Stimulus: sensory input from environment
Reaction time: amount of time taken to respond to a specific stimulus
WILHELM WUNDT (1832-1920)
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“Father of psychology”
○ Psychology = child of physiology and philosophy
○ 1879: Leipzig, Germany
Opened the first psychological laboratory
Consciousness: person’s subjective experience of the world and the mind
Structuralism: analysis of the basic elements that constitute the mind
Introspection: subjective observations of one’s own experience
○ Research method
○ Very hard to measure
EDWARD TITCHENER (1867-1927)
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Studied under Wundt
Focused on IDing basic elements of the mind
○ Was not the first to try to ID the elements of the conscious experience
FUNCTIONALISM: MENTAL PROCESSES AS ADAPTATIONS
WILLIAM JAMES (1842-1910)
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First to take scientific approach to study psych
Wrote The Principles of Psychology
Functionalism: study of how mental processes enable people to adapt to their environments
CHARLES DARWIN (1809-1882)
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Inspired James; wrote On the Origin of Species by Means of Natural Selection
Natural selection: theory that the features of an organism that help it survive + reproduce are more likely
than other features to be passed on to subsequent generations
G. STANLEY HALL (1844-1924)
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Set up first psych laboratory in North America; focused on development + education
Founded the American Journal of Psychology
JAMES MARK BALDWIN (1861-1934)
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First to open psych lab in Canada (1889); focused on infant development
Hall + Baldwin were the first developmental psychologists
THE REAL WORLD: IMPROVING STUDY SKILLS
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Rehearse
○ Spaced + elaborative rehearsal better
○ Visualization
Reflect on significance
Study smart
○ Regularly review; no cramming
○ Test yourself, hit the main points, build effective note-taking skills, organize
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Get some sleep :^)
THE DEVELOPMENT OF CLINICAL PSYCHOLOGY
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Around the time when structuralism + functionalism were being developed, some psychs worked as
clinicians in out-patient healthcare clinics + hospitals
Observations of mental disorders influenced the development of clinical psychology
LESSONS FROM WORK W/ PATIENTS
JEAN-MARTIN CHARCOT (1825-1893) AND PIERRE JANET (1859-1947)
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Studied hysteric patients through hypnosis
○ Hysteria: temporary loss of cognitive or motor functions, usually as a result of emotionally
upsetting experiences
Influenced William James + Sigmund Freud
FREUD DEVELOPS PSYCHOANALYTIC THEORY
SIGMUND FREUD (1856-1939)
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Believed hysteris is caused by painful unconscious experiences
○ Unconscious: part of the mind that operates outside of awareness but influences conscious
thoughts, feelings, actions
○ Psychoanalytic theory: approach to understanding human behav that emphasizes the importance
of unconscious mental processes in shaping feelings, thoughts, behave
○ Psychoanalysis: therapeutic approach that focuses on bringing unconscious material into
conscious awareness to better understand psych disorders
■ Treatment for neurosis/anxiety: dig into childhood memories to make the unconscious,
conscious (exploring traumas)
● Did case studies (sitting on the couch @ head of person, out of sight)
Considered to be 1 of the 2-3 most influential thinkers of the 20th C
CARL JUNG (1875-1961) AND ALFRED ADLER (1870-1937)
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Part of psychoanalytic movement
Followed Freud until he broke off relationships w/ both men
○ Split bc of Freud’s insistence on significance of childhood exps, re: psychoanalytic theory
Psychoanalytic theory became controversial
THE RISE OF HUMANISTIC PSYCHOLOGY
ABRAHAM MASLOW (1908-1970) AND CARL ROGERS (1902-1987)
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Pioneered a new movement in humanistic psychology
○ Major shift away from humanism
Humanistic psychology: approach to understanding human nature that emphasizes the positive potential
of human beings
○ Offered a positive view of human nature that matched the zeitgeist of the 1960s
■ The choices we make dictate how we do in life
■ Free will (we have the potential to become)
Importance of choices in the present to enhance an indiv’s well-being
BEHAVIOURISM: THE SEARCH FOR OBJECTIVE
MEASUREMENT
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Advocated that psychologists restrict themselves to the scientific study of objectively observable
behaviour
○ Eg kid sees mom scream from a spider => kid develops fear of spiders. Treat w/ exposure therapy
Represented a dramatic departure from previous schools of thought
WATSON AND THE EMERGENCE OF BEHAVIOURISM
JOHN B. WATSON (1878-1958)
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Influenced by Pavlov; goal was to predict + control behaviour through the study of observable behaviour
MARGARET FLOY WASHBURN (1871-1939)
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Studied behaviour in different animal species
Wrote influential book The Animal Mind
Developed a theory of consciousness
IVAN PAVLOV (1849-1936)
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Studied physiology of digestion + founded classical conditioning (stimulus-response)
○ Response: action or physiological change elicited by a stimulus
OTHER VOICES: IS PSYCHOLOGY A SCIENCE?
TIMOTHY WILSON FROM THE UNIVERSITY OF VIRGINIA
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Provides examples of psych investigations that have had beneficial effects on society
Posits that much of psych is based on carefully controlled experimentation using randomization
procedures
B.F. SKINNER AND THE DEVELOPMENT OF BEHAVIOURISM
BURRHUS FREDERICK (B.F.) SKINNER (1904-1990)
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Developed the “Skinner box” (conditioning chamber) to explain learning
○ Eg rat can press button to get food => more likely to press button; vice versa for electric shock
○ Eg token economies in prisons (give well-behaving prisoners plastic chips to trade for goods)
Founded operant conditioning
Published The Behaviour of Organisms, Beyond Freedom and Dignity, Walden II
Influenced by Benedict Spinoza (1632-1677)
Reinforcement: consequences of a behaviour that determine whether it will be more likely that the
behaviour will occur again
○ Positive punishment: physical (or psych) consequence to behav
○ Negative punishment: taking away something pleasurable
RETURN OF THE MIND: PSYCH EXPANDS
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Behaviourists dominated psych from 1930s-50s
Behaviourists ignored:
○ Mental processes
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○ Evol’nary history
Behaviourism later replaced by other approaches
PIONEERING IDEAS LEAD TO COGNITIVE PSYCHOLOGY
INSIGHTS INTO HOW THE MIND ORGANIZES WHAT WE SEE
MAX WERTHEIMER (1880-1943)
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Founded induced-motion phenomena
○ Illusions: errors of perception, memory, or judgement in which subjective exp differs from
objective reality
○ Gestalt psychology: psych approach that emphasizes we often perceive the whole (vs sum of
parts)
INSIGHTS INTO HOW THE MIND ORGANIZES MEMORY
SIR FREDERIC BARTLETT (1886-1969)
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Discovered that memory recall is flawed, in contrast to:
HERMANN EBBINGHAUS (1850-1909)
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Performed groundbreaking research on memory in 1885
INSIGHTS INTO CHILD DEVELOPMENT
JEAN PIAGET (1896-1980)
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Studied perceptual + cognitive errors in children
Theorized that younger children lack a particular cognitive ability that allows older children to appreciate
the fact that the mass of an object remains constant even when it’s divided
THE IMPORTANCE OF PERSONAL EXPERIENCE
KURT LEWIN (1890-1947)
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Studied construal of stimuli
○ Used topology to mathematically model subjective exp
Argued that ppl react to the world as they see it, not to the world as it is
COMPUTERS ENTER THE SCENE
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Cognitive psychology: scientific study of mental processes
○ Incl perception, thought, memory, reasoning
INSIGHTS INTO THE LIMITS OF ATTENTION
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During WWII the military needed help understanding the human interface w/ technology
DONALD BROADBENT (1926-1993)
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Discovered that attention has limited capacity
GEORGE MILLER (1920-2012)
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Found consistency in capacity limits in memory across situations
COMPUTER ANALOGY
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First generation of computers came about ~1950s
Emergence of computers led to reemergence of interest in mental processes all across the discipline of
psych
THE GIFT OF HUMAN LANGUAGE
NOAM CHOMSKY (B. 1928)
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Pointed out that young children generate sentences they’ve never heard before => can’t possibly be
learning language by reinforcement
THE RISE OF COGNITIVE NEUROSCIENCE
KARL LASHLEY (1890-1958)
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Wanted to figure out where memory lies in the brain
○ Lesioned rats’ brains in unsuccessful attempt to localize learning
○ Memories are stored in the area of the brain where the experience occurred
■ But memory is centered around the hippocampus
Work led to new research area of physiological psych
Behavioural neuroscience: approach to psych that links psych processes to activities in the nervous
system + other bodily processes
Cognitive neuroscience: field that attempts to understand links btw cognitive processes + brain activity
○ Eg CBT
MONTREAL
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Founded by Hebb, Penfield, Milner
○ Penfield founded the Mtl Neurological Institute + “the Montreal procedure”
○ Hebb wrote The Organization of Behaviour abt the neural basis of learning
○ Milner discovered the brain basis of long-term memory
THE ADAPTIVE MIND: THE EMERGENCE OF
EVOLUTIONARY PSYCHOLOGY
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Explains the mind + behav in terms of the adaptive value of abilities that are preserved over time by
natural selection
Inspired by the functionalist approaches of William Jamaes + G .Stanley Hall
SOCIAL PSYCHOLOGY
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Subfield of psych that studies the causes/consequences of interpersonal behav
○ Humans are soc animals; behav is influenced by presence + absence of other people
○ How does the group affect the person?
SOLOMON ASCH (1907-1996)
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Studied “mental chemistry”
Studies on obedience in lab experiments
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Eg getting people to administer (lethal) electric shock
GORDON ALLPORT (1897-1967)
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Studied stereotyping, prejudice, racism as perceptual errors
CULTURAL PSYCHOLOGY
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Study of how cultures reflect + shape the psych processes of their members
○ Studied by psychs + anthropologists
Absolutism: culture makes little difference for most psych phenomena
Relativism: psych phenomena are likely to vary considerably across cultures
THE PROFESSION OF PSYCHOLOGY: PAST AND PRESENT
APA (EST 1892)
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Founded by 7 men (each worked at a large uni where they taught psych, did research + wrote textbooks)
Today, academic psychs make up 20% of membership; 70% work in clinical + health-related settings
AP SOCIETY (1988)
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Begun for academic research psychs
2006: changed name to Assoc’n for Psychological Science
CANADIAN PSYCHOLOGICAL ORGANIZATIONS
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Cdn Psych Assoc’n
Cdn Society for Brain, Behaviour and Cognitive Science
Cdn Assoc’n for Neuroscience
WHAT PSYCHOLOGISTS DO: RESEARCH CAREERS
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Most undergrad students go to grad school + do research
○ Postdoctoral fellowships in different areas of psych
○ Faculty positions (teaching + research)
○ Research position in industry
Variety of career paths
○ Clinical psych; counseling psych; school psych; industrial/organizational psych; etc
○ Clinical psych makes up almost half of the doctorates awarded in psych
Psychologist vs psychiatrist
○ Psychiatrists have MDs
○ Psychologists have PhDs
WEEK 2 - CHAPTER 2: RESEARCH METHODS
THE SCIENTIFIC METHOD
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Set of principles abt the appropriate relationship btw ideas using empirical evidence
Empiricism: belief that accurate knowledge can be acquired through observation
○ Essential element in scientific method
Theory: hypothetical explanation of a natural phenomena
○ Collection of experiments + assumptions that provide us w/ predictability
■ Deductive reasoning
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○ Enhance w/ research questions/hypotheses
○ Rule of parsimony: simplest theory that explains all the evidence is the best one
Hypothesis: falsifiable prediction made by a theory
Empirical method: set of rules + techniques for observation
○ People are difficult to study bc of complexity, variability, reactivity
○ Methods of observation and explanation must be used
OBSERVATION: DISCOVERING WHAT PEOPLE DO
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Observe: use one’s senses to learn about the properties of an event or object
Scientists have devised techniques to overcome problems of:
○ Casual observations, which are notoriously unstable
○ Unknown properties that may interest us
Psychologists:
○ Design instruments to make measurements => analyze these measurements
MEASUREMENT
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Basic part of modern life
Requires:
○ Definition of the property being measured, and
■ Generate an operational definition that has validity
○ A way to detect it
■ Design an instrument that has reliability + power
Operational definition: description of a property in concrete, measurable terms
○ A good definition is valid, reliable, and powerful
■ Validity: extent to which a measurement + property are conceptually related
● Accuracy
■ Reliability: tendency for a measure to produce the same measurement whenever it is used
to measure the same thing
● Consistency
■ Power: ability of a measure to detect the concrete conditions specified in the operational
definition
Instrument: anything that can detect the condition to which an operational definition refers
Measure: device that can detect the condition to which an operational definition refers
DEMAND CHARACTERISTICS: DOING WHAT IS EXPECTED
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Demand characteristics: those aspects of an observational setting that cause people to behave as they
think someone else wants or expects
○ Such characteristics make it hard to measure behaviour as it it typically unfolds
Naturalistic observation: technique for gathering scientific information by unobtrusively observing
people in their natural environments
○ Eg Jane Goodall
Observer bias: expectations can influence observations + influence perceptions of reality
Double-blind observation: observation whose true purpose is hidden from both observer + person being
observed
○ Eg subject and researcher doesn’t know whether subjects receive cocaine or baking soda
○ Inert = doesn’t do anything
DESCRIPTION
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Psychs have 2 techniques for analyzing data:
○ Graphic representations => describe data
○ Descriptive statistics
■ Brief summary statements abt essential info from a frequency distribution
GRAPHIC REPRESENTATIONS
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Frequency distribution: graphical representation of measurements arranged by # of times each
measurement was made
Normal distribution: mathematically defined frequency distribution in which most measurements are
concentrated around the middle
DESCRIPTIVE STATISTICS
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Central tendency (centre or midpoint)
○ Mode: value of the most frequently observed measurement
○ Mean: avg value of all measurements
○ Median: value in the middle
Skewed distributions: non-normal (pos or neg skew) when frequency distributions are not normal
Variability (extent measurements differ)
○ Range: value of the largest measurement in a frequency distribution minus the value of the
smallest measurement
○ Standard deviation: statistic that describes the avg difference btw the measurements in a
frequency distribution + the mean of that distribution
EXPLANATION
CORRELATION
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Ultimate goal of scientific research:
○ Discovery of causal relationships btw properties
○ Study of patterns of variation in a series of measurements
Variable: property whose value can vary across indivs or over time
Correlation: 2 variables are said to be correlated when variations in the value of 1 variable are
synchronized w/ variations in the value of the other
○ Can be pos or neg
MEASURING THE STRENGTH OF A CORRELATION
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Correlation coefficient: measure of the direction + strength of a correlation ®
○ r ranges:
■ -1.0 = perfect negative correlation
■ +1.0 = perfect positive correlation
■ 0 = no correlation
CAUSATION
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Sometimes we see causal relationships that do not actually exist
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Natural correlations: correlations observed in the world around us
Third-variable problem: the fact that a causal relationship btw 2 variables cannot be inferred
from the naturally occurring correlation btw them bc of the ever-present possibility of a thirdvariable correlation
■ Matched samples technique: whereby the participants in 2 groups are identical in terms of
a third variable
■ Matched pairs technique: whereby each participant is identical to one other participant in
terms of a third variable
EXPERIMENTATION
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Experiment: technique for establishing the causal relationship btw variables
○ Eliminate differences btw groups by examining 2 key features:
MANIPULATION
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Creation of an artificial pattern of variation in a variable in order to determine its causal power
○ IV = manipulated variable; DV = variable that is measured
○ Experimental group vs control group
■ Eg exposing to media violence vs not
RANDOM ASSIGNMENT
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Procedure that lets chance assign participants to the experimental or control group
Self-selection: problem that occurs when anything abt a participant determines whether they will be
included in the experimental or control group
STATISTICAL TESTING
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Statistical significance: determined when we calculate the odds that random assignment has failed,
through inferential statistics
○ Not accepted unless that chance is less than 5% (p ≤ .05)
DRAWING CONCLUSIONS
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Internal validity: an attribute of an experiment that allows it to establish causal relationships
External validity: an attribute of an experiment in which variables have been defined in a normal, typical,
or realistic way
SAMPLING - REPRESENTATIVE PEOPLE
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Population: complete collection of participants who might possibly be measured
Sample: partial collection of people drawn from a population
Case method: method of gathering scientific knowledge by studying a single indiv
Random sampling: technique for choosing participants that ensures every member of a pop has an equal
chance of being included in the sample
Nonrandom sampling
○ Acceptable technique if similarity btw a sample and pop doesn’t matter,
○ When direct replication is available,
○ If similarity btw the 2 is a reasonable starting assumption
THINKING CRITICALLY ABOUT EVIDENCE
CRITICAL THINKING
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Involves asking Qs abt whether evidence has been interpreted in an unbiased way
○ Whether evidence tells not just the truth, but the whole truth
People to struggle to think critically
○ Thinking intuitively was more advantageous for hunter-gatherers, vs today’s large-scale +
complex societies
○ We see what we expect + want to see
○ We tend to ignore what we don’t see
The skeptical stance: scientists constantly strive to make their observations more accurate + reasoning
more rigorous
ETHICS
RESPECTING PEOPLE
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Psychs go to great lengths to protect well-being of research participants + bound by code of ethics
Research should show respect for persons, be beneficient, + be just
Ethical reporting of data is necessary + approval from research ethics boards should be gained
○ Research in CA is covered by the Tri-Council Policy Statement: Ethical Conduct for Research Involving
Humans
APA CODE OF ETHICS
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Informed consent
Freedom from coercion
Protection from harm
Risk-benefit analysis
Deception
Debriefing
Confidentiality
RESPECTING PEOPLE
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Cdn Council on Animal Care oversees nat’l standards:
○ Replacement (must show you have to use animals)
○ Reduction (use smallest number possible)
○ Refinement (minimize discomfort)
Most Cdns (57-64%) support animal research
RESPECTING TRUTH
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Psych (like all sciences) works on the honour system
○ Results are reported truthfully on what was done + what was found
○ Credit is ethically assigned
○ Data are shared
OTHER VOICES: CAN WE AFFORD SCIENCE?
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Taxpayer dollars fund much psych science
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Cass Sunstein argues that this research is an investment that pays for itself:
○ Many past policies were based on overly simplistic views of human nature
○ Policies are best designed around current knowledge of people + contexts
WEEK 3: CH 3 - NEUROSCIENCE AND
BEHAVIOUR
NEURONS: THE ORIGIN OF BEHAVIOUR
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Neurons: cells in the nervous system that communicate w/ one another to perform info-processing tasks
○ ~100B in brain
○ Process all thoughts, feelings, behave
○ Take info => produce output
COMPONENTS OF THE NEURON
COMPONENT
FUNCTION
Cell body
Coordinates info-processing tasks + keeps cell alive
Dendrite
Branches that receive info from other neurons + relays to cell body
Axon
Transmits info to other neurons, muscles, or glands
Myelin sheath
Provides insulating layer of fatty material
Increases speed of info transmission
Glial cells
Support cells found in NS
Facilitates nutritional supply to neuron
Synapse
Junction/region btw axon of one neuron and dendrites or cell body of another
Small synaptic space btw neurons where info is transmitted
GOLGI-STAINED NEURONS
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Used by Santiago Ramon y Cajal to highlight appearance of neurons
○ First to observe each neuron is composed of body w/ many threads outward towards other
neurons
Threads of each neuron do not actually touch other neurons
[diagram: figure 3.2 - components of the neuron]
NEURONS SPECIALIZED BY FUNCTION
SENSORY NEURONS
● Receive info from external world => convey info to brain via spinal cord
○ Receive signals for light, sound, touch, taste, smell
● Afferent neurons
○ Eg relay pain signals
MOTOR NEURONS
● Carry signals from spinal cord to muscles to produce movement
● Often have long axons that reach to muscles at extremities
INTERNEURONS
● Connect sensory neurons, motor neurons, or other interneurons
● Only found in brain + spinal column
NEURONS SPECIALIZED BY LOCATION
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Neurons contain cell body, axon, 1+ dendrite
Size + shape varies considerably [diagram]
THE ELECTROCHEMICAL ACTIONS OF NEURONS:
INFORMATION PROCESSING
ELECTROCHEMICAL ACTION (2 STAGES)
1. Conduction: Movement of electrical signal within neurons
2. Transmission: Movement of electrical signal from one neuron to another due to signaling across synapse
ELECTRIC SIGNALING: CONDUCTING INFO WITHIN A NEURON
Neurons have a natural electrical charge that changes as info is passed
Resting potential: Difference in electric charge btw inside and outside of neuron’s cell membrane
○ Discovered in 1939 by biologists Alan Hodgkin + Andrew Huxley while studying sea invertebrates
● Action potential: Electric signal that is conducted along a neuron’s axon to a synapse
○ Change in voltage in cell
○ Threshold is reached: “all-or-none”
■ Need minimum amount of stimulation to activate system
○ Refractory period: time following an action potential during which a new action potential cannot
be initiated
■ Few milliseconds where neurotransmitters must be reuptaken
[diagram: figure 3.4 - the resting and action potentials]
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CHEMICAL SIGNALING: TRANSMISSION BETWEEN NEURONS
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Info is passed btw neurons via neurotransmitters
Terminal buttons: knoblike structures that branch out from an axon
Neurotransmitters: Chemicals that transmit info across synapse to a receiving neuron’s dendrites
○ Reuptake, enzyme deactivation, autoreceptor binding
Receptors: parts of cell membrane that receive neurotransmitter + initiate or prevent a new electric
signal
MYELIN AND NODES OF RANVIER
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Myelin is formed by a type of glial cell
○ Wraps around neuron’s axon to speed movement of action potential along the length of the axon
○ 200 mph
Nodes of Ranvier: Breaks in myelin sheath
○ Electric impulse jumps to each node => speeds conduction of info down the axon
SYNAPTIC TRANSMISSION
1. Action potential travels down axon
2. Action potential stimulates release of neurotransmitters from vesicles
3. Neurotransmitters get released into synapse => float to bind w/ receptor on dendrite of a postsynaptic
neuron => initiates new action potential
Neurotransmitters get cleared out of synapse by:
● Reuptake into sending neuron
● Being broken down by enzymes in synapse, or
● Binding to autoreceptors on sending neuron
TYPES AND FUNCTIONS OF NEUROTRANSMITTERS
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Some 60 neurotransmitters affect thought, feeling, behav in different ways
○ Acetylcholine (ACh)
○ Dopamine (DA)
■ Parkinson’s (low); schizophrenia (high)
○ Glutamate (gamma-aminobutyric acid)
○ GABA
○ Norepinephrine (NE)
○ Serotonin (5-HT)
○ Endorphins
Always want to look at benefits + side effects
HOW DRUGS MIMIC NEUROTRANSMITTERS
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Drugs increase, interfere w/, or mimic neurotransmitters
○ Agonists: Drugs that increase action of a neurotransmitter (facilitate firing)
○ Antagonists: Drugs that block function of a neurotransmitter
Examples: L-dopa, heroin (MPPP and MPTP), methamphetamine, amphetamine, cocaine, Prozac (SSRI),
propranalol (beta-blocker)
[diagram: the actions of agonist and antagonist drugs]
THE ORGANIZATION OF THE NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM (1/2)
● Receives sensory info from external world
● Processes + coordinates info => commands skeletal + muscular systems for action
BRAIN
● Supports perception, motor functions, emotion, cognition
SPINAL CORD
● Branches down from brain
● 4 main sections
○ Cervical
○ Thoracic
○ Lumbar
○ Sacral
● Damage higher on spinal cord usually means greater impairment
TASKS
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Spinal reflexes: Simple pathways in NS that rapidly generate muscle contractions
○ Eg pain withdrawal reflex
■ Many actions don’t require brain’s input
■ Painful sensations travel directly to spinal cord via sensory neurons => immediate
command to motor neurons to retract hand
Reflex arc: Neural pathway that controls reflex actions
PERIPHERAL NERVOUS SYSTEM (2/2)
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Connects CNS to body’s organs + muscles
NS
FUNCTION
Somatic nervous system
Conveys info into/out of CNS
Autonomic nervous systems (ANS)
Carries involuntary + automatic commands
Control blood vessels, body organs, glands
Sympathetic nervous system
Prepares body for action in threatening situations
Parasympathetic nervous system
Helps body return to normal resting state
STRUCTURE OF THE BRAIN
DIVISION
FUNCTION
EXAMPLE
Hindbrain
Coordinates info coming in/out of spinal cord
Controls basic functions of life
Medulla, reticular formation,
cerebellum, pons
Midbrain
Orientation and movement
Tectum, tegmentum
Forebrain
Highest level of brain
Critical for complex cognitive, emotional,
sensory, motor functions
Cerebral cortex, subcortical
structures
SUBCORTICAL STRUCTURES
LIMBIC SYSTEM
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Group of forebrain structures
Motivation, emotion, learning, memory
STRUCTURE
Thalamus
Hypothalamus
FUNCTION
Receives inputs from all major senses (except smell)
Relays + filters info from senses => transmits info to cerebral cortex
Emotional control center
Regulates body temp, hunger, thirst, sexual behav
Amygdala
Hippocampus
Plays central role in many emotional processes, esp formation of emotional memories
Critical for creating new memories + integrating into knowledge network => store
indefinitely in other parts of cerebral cortex
THE ENDOCRINE SYSTEM
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Network of glands that produces + secretes hormones (chemical messengers) into bloodstream
○ Influences basic functions (eg metabolism, growth, sexual maturation)
Pituitary gland: “Master gland”; releases hormones that direct fxns of many other glands
THE CEREBRAL CORTEX
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4 lobes (in each hemisphere); highest level of the brain
○ Frontal lobe: Specialized areas for movement, abstract thinking, planning, memory, judgement
○ Parietal lobe: Process info about touch
○ Temporal lobe: Hearing + language
○ Occipital lobe: Processes visual info
Association areas: Composed of neurons that help provide sense + meaning to info registered in cortex:
○ Help synthesize threads of info in various parts of cortex
○ Threads produce meaningful understanding of what is being registered in the brain
○ Mirror-neuron system
R/L hemispheres connected by corpus callosum
○ L: accountant
○ R: artistic side (not time-oriented)
SOMATOSENSORY CORTEX
●
●
Somatosensory cortex: Represents skin areas on contralateral surface of the body
Homunculus: Rendering of the body in which each part is shown in proportion to how much of the
somatosensory cortex is devoted to it
○ Much mapped by Penfield by stimulating brains of awake PTs + recording where PT felt sensation
MIRROR-NEURON SYSTEM
●
●
●
Frontal + parietal lobes; also in other species
Stimulates motor learning by watching others
Benefit soc learning => enhance our own ability to perform
BRAIN PLASTICITY
●
Adaptive feature; allows nerve signals to go around damaged areas, accommodate changing input from
environment
○ Greater use of a fxn may command greater space in cortical map
○ Physical exercise can benefit strength + connections of synapses in the brain
PHANTOM LIMB SYNDROME
●
●
PTs continue to feel sensations in missing limbs after amputation
Stimulating areas of face + other body parts may activate sensations in missing limb
○ Compensation of cortical area in somatosensory cortex
●
Researchers used “mirror box” to teach amputees a new mapping to increase voluntary control over
phantom limbs
THE DEVELOPMENT AND EVOLUTION OF NERVOUS
SYSTEMS
EVOLUTION
●
●
●
CNS evolved; even the simplest animals have sensory + motor neurons
Split in NS occurred btw vertebrates + invertebrates
Human brain has evolved more quickly than brains of other species
PRENATAL DEVELOPMENT OF THE CNS
●
●
NS is first major bodily system to take form in an embryo (3rd week)
○ Neural tube forms => eventually becomes spinal cord
V important for mother to eat protein while pregnant
COMPONENT
TIME
3 basic levels of brain
Visible by week 4
Forebrain, hindbrain differentiate into subdivisions
Week 5
Cerebral hemispheres form
Week 7+
GENES, EPIGENETICS, AND THE ENVIRONMENT
●
●
●
Unit of hereditary transmission; sections on DNA strands organized into chromosomes
○ Chromosomes: Double-helix of DNA strands
Degree of relatedness: Monozygotic vs dizygotic
○ Twin studies
Heritability: Measure of variability of behav’l traits among indivs that can be accounted for genetically
○ Abstract concept
○ Population concept
○ Dependent on environment
○ Not fate
EPIGENETICS
●
●
There are environmental triggers that turn genes on/off
○ Doesn’t alter basic DNA sequence of genes
Epigenetic marks: Chemical modifications to DNA (turn genes on/off)
○ DNA methylation: Adding a methyl group to DNA
○ Histone modification: Adding chemical modifications to histones that help in packaging DNA
INVESTIGATING THE BRAIN
STUDYING THE DAMAGED BRAIN
THE EMOTIONAL FUNCTIONS OF THE FRONTAL LOBES
●
Phineas Gage
○
Impaled by metal rod through frontal lobe
DISTINCT ROLES OF THE L/R HEMISPHERES
●
●
ROGER WOLCOTT SPERRY (1913-1994) investigated independent fxns of other cerebral hemispheres
○ L: verbal; R: spatial
Split-brain studies: Hemispheres perform different fxns + can work together seamlessly as long as corpus
callosum remains intact
STUDYING THE BRAIN’S ELECTRICAL ACTIVITY
●
●
Electroencephalograph (EEG): Device used to record electrical activity in brain
Hubel and Wiesel: inserted electrodes into brains of anaesthetized cats => found feature detectors by
mapping visual cortex
BRAIN IMAGING
●
Neuroimaging techniques create images of living, healthy brain
○ CT scan, MRI, DTT
FUNCTIONAL BRAIN IMAGING
Shows brain activity while someone engages in a cognitive or motor task
○ PET; MRI
INSIGHTS FROM FUNCTIONAL IMAGING
● Insights into types of info processing that take place in specific areas of the brain
● Possibly confirm theories derived over last century
● Need to be cautious abt how evidence from fMRI is obtained
●
TRANSCRANIAL MAGNETIC STIMULATION (TMS)
●
●
Brain damage may be related to particular patterns of behaviour in ppl w/ brain injuries
○ Relationship may not be causal
TMS methods can (ethically) mimic brain damage
○ Temporarily deactivates neurons in cerebral cortex
○ Can be combined w/ fMRI technique
○ Manipulation can provide causal explanations
WEEK 5 - CH 3 (GRAY): GENETICS AND
EVOLUTIONARY FOUNDATIONS OF
BEHAVIOUR
DARWIN’S THEORY
●
●
●
~150 yrs ago: Darwin’s theory of evolution => explain differences + similarities btw species
○ Theory applied today by evol’nary scientists to explain behaviour
Natural selection: Inherited traits that better an organism’s likelihood of survival will most likely be
passed on to the next generation
Evol’nary psych is based upon the principles of NS
HOW GENES AFFECT BEHAVIOUR
●
●
●
Gene “for”...
Genes provide codes for proteins
○ Structural proteins
○ Enzymes
○ DNA
■ Coding genes: Templates for RNA => templates for production of proteins
■ Regulatory genes: Regulate activity of coding DNA
Genes work only through interxn w/ environment
○ Environment = every aspect of an indiv +
their surroundings except the genes
themselves
○ Continuous complex interplay btw gene +
environment
■ Feedback loop of internal
environment controlling gene
activation => can affect behaviour
=> can affect gene activation
GENOTYPE vs PHENOTYPE
●
●
●
●
Genotype: Set of genes that an indiv inherits
Phenotype: Observable properties of the body + behav’l traits
○ Eg brow ridge expressed in Down Syndrome
○ Twins share similar preferences even when raised apart
Heritability: Trait differences attributable to genetic variation in the population
Different types of geneticists (eg behavioural geneticist interested in personality traits)
GENE REPRODUCTION
●
●
●
DNA exists in chromosomes (human cells have 23 pairs)
○ All humans have 22 of those pairs; last pair is sex chromosomes (eg XX females; XY males)
○ Genes make up chromosomes, which make up DNA
One member of pair comes from each parent
Mitosis (somatic) vs meiosis (reproductive cells replicate + divide to create nonidentical cells)
GENETIC DIVERSITY OF OFFSPRING
●
●
●
Genes have better chance of survival if rearranged at each generation
Twins are the only offspring that are not diverse
○ Identical (mono/homozygotic); fraternal (di/heterozygotic)
Stages of development
○ Zygotic (first 2 weeks)
○ Embryonic (2-8 weeks)
○ Fetal (8 weeks to full gestation)
GENE EXPRESSION
●
●
●
Alleles: Different genes that can occupy same locus => can potentially pair w/ each other
Dominant gene: Will produce observable effects in either homozygous or heterozygous condition
Recessive gene: Will only produce observable effects in homozygous condition
MENDELIAN PATTERN OF HEREDITY
●
●
Mendel came up w/ idea of dominant vs recessive genes
Discovered that some behaviours are affected by a single gene
○ Eg fearfulness in dogs; KE family language disorder
POLYGENIC CHARACTERISTICS & SELECTIVE
BREEDING
●
●
Selective breeding: Modifying a specific behaviour or
characteristic by mating indivs with or w/o the specific
characteristics
○ Eg eugenics
Bioethics
○ Should we look at in-vivo conditions to prepare parents for children who may have disabilities?
EPIGENETICS
●
●
Epigenetics: Examines gene-regulating activity that doesn’t involve changes to DNA code + can persist
through 1+ generations
○ What environmental factors turn a gene on/off?
DNA methylation = best-understood mechanisms for epigenetic effects
○ Some epigenetic markers created by methylation can be inherited + behaviour they influence
○ Doudna and Charpentier: 2021 Nobel Prize for CRISPR technology (gene-editing technology)
EVOLUTION BY NATURAL SELECTION
●
●
Darwin: On the Origin of Species
○ Artificial selection: Human-controlled selective breeding
○ Natural selection: Selective breeding in nature
Darwin’s essential point: Indivs of a species vary in the # of offspring they produce
○ Traits that increase # offspring will be selected “for”
■ Traits must promote survival + procreation
○ Traits that decrease # offspring will be selected “against”
DARWIN’S CORE CONCEPTS OF NATURAL SELECTION
●
●
●
●
There is overproduction of offspring in each generation
There is variation in features/traits within members of a generation
Indiv differences are inherited from one generation to the next
Indivs w/ collections of traits that fit well w/ local environment are more apt to survive + have more
offspring (vs indivs whose traits don’t fit as well)
GENETIC DIVERSITY PROVIDES MATERIAL FOR NATURAL SELECTION
●
2 sources of genetic variability on which natural selection acts
a. Reshuffling of genes during reproduction
b. Mutations: Errors that occasionally + unpredictably occur during DNA replication
■
■
Something that changes in genetic pathway to create something new
Eg fish that swim in poisoned water develop tumours
ENVIRONMENTAL CHANGE PROVIDES FORCE FOR NATURAL SELECTION
●
●
●
Evol’n spurred by environmental changes
Environment can cause appropriate mutations that change + promote natural selection
Grant & Grant’s work on finches
EVOLUTION HAS NO FORESIGHT
●
●
●
Evol’nary paths are not working toward some predetermined end
Humans =/= “most evolved” species
NS =/= moral force
○ Naturalistic fallacy
NATURAL SELECTION AS A FOUNDATION FOR FUNCTIONALISM
● Functionalism: Attempt to explain behaviour in terms of what it accomplishes for the behaving indiv
● Tries to answer how a trait helped ancestral members of the species survive + reproduce
DISTAL EXPLANATIONS
● Functional explanations @ evol’nary level
● Distal causation sometimes referred to as “ultimate causation”
PROXIMATE EXPLANATIONS
● Explanations that deal w/ mechanism in the immediate conditions
LIMITATIONS ON FUNCTIONALIST THINKING
●
●
●
●
Some traits are vestigial
Some traits are side effects of natural selection for other traits
Some traits result from chance
Evolved mechanisms cannot deal effectively w/ every situation
SPECIES-TYPICAL BEHAVIOURS IN HUMANS
●
●
●
●
Human emotional expression
○ Darwin
○ Ekman and Friesen
○ Eibl-Eibesfeldt
Role of learning in developing species-typical behaviour
Biological preparedness + species-typical behaviour
○ Eg infants born w/ stepping reflex
Species-typical behaviour is a relative concept
STUDYING BEHAVIOUR (QUESTIONS)
●
●
●
●
What are the environmental conditions needed for the full development of this behaviour?
What internal mechanisms are involved in producing this behaviour?
What consequences does this behaviour have in this indiv’s daily life?
In the course of evolution, why would the genes that make this behaviour possible have been favoured by natural
selection?
CROSS-SPECIES COMPARISONS
●
●
Homologies: Similarities due to common ancestry
○ Useful for studying underlying mechanisms + for tracing evol’nary course of species-typical
behaviours
■ Eg research on greeting smile + happy smile in humans)
○ Useful for inferring pathways along which species-typical behaviours evolved
Analogies: Similarities due to convergent evolution (independent evol’n of similar traits)
○ Useful for inferring distal fxns
EVOLUTIONARY ANALYSES OF MATING PATTERNS
MATING PATTERNS AND PARENTAL INVESTMENT
MATING PATTERN
LEVEL OF INVESTMENT
Polygyny
Related to high female + low male parental investment
Polyandry
Related to high male + low female parental investment
Monogamy
Related to equivalent M/F parental investment
Promiscuity
Related to investment in the group
EMOTIONS AND HUMAN MATING
●
●
●
Human mating mostly monogamous + partly polygamous
Romantic love + mating
Jealousy + mating
SEX DIFFERENCES IN AGGRESSION
●
●
Male primates (incl. men) generally more violent than females of their species
Most aggression/violence in male primates relate directly/indirectly to sex
○ Genes that promote violence get passed to offspring to the deg that they increase reproduction
EVOLUTIONARY ANALYSES OF HELPING AND HURTING: COOPERATION
●
Helping: Promoting another’s survival or reproduction (2 forms)
○ Cooperation: Helping others while also helping oneself
■ Easy to understand evolutionarily
■ Eg wolves hunting together
○ Apparent acts of altruism: Helping others at a net cost to oneself
■ Make evolutionary sense if explained by kin selection or reciprocity theories
TAKEAWAYS
●
●
●
●
●
Nature vs nurture (they work together)
Collectivist vs individualistic societies
○ Collectivists more interested in soc harmony
Mutation (eg cancer)
Prenatal genetic testing
Enriched vs impoverished environments (eg post-secondary education vs Ozark)
●
●
●
●
●
●
●
●
○ Significant differences in synaptic changes in development
Biological differences btw M/F (sex characteristics, not gender)
Pruning: If you don’t use something, the neuropathways don’t get exercised and thus die
Aggression: Physical or verbal intent to hurt someone
Androgyny: Blend of M/F
Jung: Anima/animus; yin/yang
Primary (what you’re born with) vs secondary characteristics (puberty)
Heritability: Differences among people influenced by genes
[video: Steven Pinker and Richard Dawkins]
WEEK 6 - CH 11: DEVELOPMENT
●
●
Developmental psychology: The study of continuity + change across the life span
○ Age-related changes (eg what can you do at 12 that you can’t do at 4?)
■ Social, cognitive, physical
○ Infancy, childhood, adolescence, adulthood
In-vivo learning
○ Fetuses can learn while in the womb (eg heartrate goes down when hearing voice of mother, vs a
stranger)
PRENATAL STAGES (3)
1. Germinal stage
○ 2-week period that begins at conception; brief lifetime of zygote
i.
Zygote: Fertilized egg that contains chromosomes from both a sperm + egg
○ Time when ovum will split into twins
2. Embryonic stage
○ Period that lasts from 2nd to 8th week
○ 7 week mark: Testosterone develops males as male
i.
M/F ovums same up until this point
3. Fetal stage
○ Period that lasts from 9th week until birth
○ Myelination: Formation of fatty sheath around axons of a neuron
i.
Super important for mothers to eat proteins during pregnancy => enhance protein
synthesis for baby
WHY ARE HUMANS BORN WITH UNDERDEVELOPED BRAINS?
●
●
Newborns’ heads would not pass through birth canal if adult-sized
Humans need to adapt to wide range of environments throughout life span => brain must be able to
develop to meet these challenges
PRENATALITY: A WOMB WITH A VIEW
PRENATAL ENVIRONMENT
●
●
Womb: Environment that affects unborn baby in many ways
Placenta: Organ that links bloodstream of mother to unborn baby; permits exchange of materials
○ Foods + substances a mother ingests affect development
○ Teratogens: Agents (eg drugs, viruses) that pass from mother + impair process of development
■ Eg HIV/AIDS, Thalidomide, red dyes, certain sweeteners, smoking
○
Fetal alcohol syndrome: Developmental disorder that stems from heavy alcohol use by mother
during pregnancy
■ Alcohol impairs cognitive development
■ Phenotypical changes: Flattened brow ridges, thin upper lip, smaller distance btw upper lip
and nose
INFANCY AND CHILDHOOD: DOING AND THINKING
●
Infancy: Stage of development that begins at birth; lasts btw 18-24 mos
○ Infants capable of much more than we initially thought; do more than sleep, squall, squirm
PERCEPTUAL DEVELOPMENT
NEWBORNS
● Poor distance vision (can see things 8-12” away)
○ Until 5 mos
● Habituate to visual stimuli => respond less to repeated exposure of same stimuli
○ Child would want to look at a face the longest before looking away
○ Innate visual gaze pattern: Want to figure out if something is a friend or foe
● Can see squares, triangles, diagonal lines
● Can mimic facial expressions within first hour of life
MOTOR DEVELOPMENT
●
●
Newborns must strengthen muscles + work on motor development
○ Motor development: Emergence of ability to execute physical action
■ Strict sequence (but not strict timetable)
● Hopi Indian study
■ Good nutrition = most important
○ Motor reflexes: Specific patterns of motor response that are triggered by specific patterns of
sensory stimulation
■ Innate; survival mechanism
■ Eg baby will turn face when stroked, curl toes when feet tickled, look up when placed face-down,
swimming reflex
Development of sophisticated behaviours follows 2 general rules:
○ Cephalocaudal rule: “Top-to-bottom” rule that describes tendency for motor skills to emerge in
sequence from head to feet
○ Proximodistal rule: “Inside-to-outside” rule that describes tendency for motor skills to emerge in
sequence from center to periphery
COGNITIVE DEVELOPMENT
●
Cognitive development: Emergence of ability to think + understand
JEAN PIAGET (1896-1980)
Suggested 4 stages of cognitive development in which infants + children learn
○ How the physical world works
○ How their minds represent it
○ How other minds represent it
SENSORIMOTOR STAGE (BIRTH - 2 YEARS)
●
Infants acquire info abt world by sensing it + moving around within it
○ Schemas: Theories about or models of the way the world works
■ Eg cars belong to the category of automobiles
○ Assimilation: Process by which infants apply their schemas in novel situations
○ Accommodation: Process by which infants revise their schemas in light of new info
■ Distinguish different members of a category
■ Eg learn that truck =/= car, but truck = automobile
○ Object permanence: Idea that objects continue to exist even when they’re not visible
PREOPERATIONAL STAGE (2-6 YEARS)
● Children have a preliminary understanding of the physical world
○ Eg think that a taller glass contains more liquid
● Egocentrism: Failure to understand that the world appears different to different observers
○ Thinking everyone thinks exactly as you do
○ No understanding of intent
● Fantasy + make-believe
CONCRETE OPERATIONAL STAGE (6-11 YEARS)
● Children learn how various actions/operations can affect/transform concrete objects
○ Conservation: Notion that the quantitative properties of an object do not vary despite changes in
object’s appearance
FORMAL OPERATIONAL STAGE (11+ YEARS)
● Children can solve non-physical problems; abstract thinking; proportional reasoning
●
STAGE
Sensorimotor (Birth - 2 yrs)
Preoperational (2-6 yrs)
CHARACTERISTIC
Infant exps world through movement + senses
Develops schemas
Begins to act intentionally
Shows evidence of understanding object permanence
Stranger anxiety
Child acquires motor skills but doesn’t understand conservation of physical
properties
Begins stage by thinking egocentrically, but ends w/ basic understanding of
other minds
Concrete operational (6-11 yrs) Child can think logically abt physical objects + events
Understanding of intent
Understands conservation of physical properties
Formal operational (11+ yrs)
Child can think logically abt abstract propositions + hypotheticals
DISCOVERING OTHER MINDS
●
●
●
●
Egocentrism: Failure to understand that the world appears different to different observers
Perceptions and beliefs
○ 3 Y/Os fail to realize that other people don’t see/know what they know
■ False-belief task
Desires and emotions
○ Children have difficulty understanding different emotional rxhs in others, until ~6 y/o
Theory of mind: Understanding the mind produces representations of the world which guide behaviour
Having an appreciation for how others feel/think
■ Children w/ autism + deaf children whose parents do not use ASL have difficulty w/ theory
of mind
○ Language is important for development of this theory
Piaget remixed criticisms of Piaget’s theory
○ Newer theories see stages as continuous, not discrete
○ Children may acquire abilities earlier than proposed
○
●
DISCOVERING OUR CULTURES
LEV VYGOTSKY (1896-1934)
●
●
●
●
Believed children develop through interxns w/ members of their own culture
Cultural tools have a strong influence on cognitive development
Scaffolding metaphor
Emphasized inner speech
●
Ability to learn from others depends on 3 fundamental skills
○ Joint attention: Ability to focus on what another person is focused on
○ Social referencing: Ability to use another person’s rxns as info abt how to think abt the world
○ Imitation: Ability to do what another person does
INFANCY AND CHILDHOOD: CARING AND BELONGING
●
Caregivers are essential for survival of human infants
○ Provide warmth, safety, food, soc development
SOCIAL DEVELOPMENT
HARRY HARLOW (1905-1981)
●
●
●
Conducted attachment experiments w/ baby rhesus monkeys
Discovered that when monkeys deprived of soc contact in first 6 mos, they:
○ Developed behavioural abnormalities
■ Eg preferred comfort + warmth of soft cloth mother vs wire mother (even though assoc’d w/ food)
○ Were incapable of communicating w/ or learning from others
○ Were incapable of normal sexual behaviour
More secure attachment = more likely to take risks + explore the world
KONRAD LORENZ (1903-1989)
●
Discovered concept of imprinting in newly hatched goslings
○ Imprinting: Phase-sensitive learning (critical periods)
JOHN BOWLBY (1907-1990)
● Argued that infants innately channel their signals to primary caregivers to form attachment
● Attachment: Emotional bond that forms btw newborns + primary caregivers
ATTACHMENT STYLES
● Strange situation: Behavioural test developed by Mary Ainsworth; used to determine child’s attachment
style
● Cultural differences in some attachment styles
ATTACHMENT STYLE
DEFINITION
Secure
Infant not distressed when caregiver leaves
Acknowledges return
60% of American infants
Avoidant
Infant not distressed when caregiver leaves
Does not acknowledge return
20%
Ambivalent
Disorganized
Infant distressed when caregiver leaves
Difficult to calm when returns
15%
No consistent response patterns
5%
THE ORIGINS OF ATTACHMENT STYLES
●
●
●
Temperaments: Characteristic patterns of emotional reactivity
○ Variable + stable; biological
Mother’s sensitivity + responsiveness matter
○ Easy babies: 40%
○ Difficult babies: 10%
○ Slow-to-warm-up babies: 15%
Internal working model of relationships: Set of believes abt the self, primary caregiver, and relationship
btw them
THE EFFECTS OF ATTACHMENT STYLES
●
Securely attached children do better than insecurely attached children
○ Academic achievement
○ Cognitive functioning
○ Psychological well-being
○ Success in adulthood
○ Emotional adjustment
MORAL DEVELOPMENT
KNOWING WHAT'S RIGHT: JEAN PIAGET (1896-1980)
●
●
Investigated children’s moral thinking + behaviour; drew several conclusions
Children’s moral thinking shifts from:
○ Realism => relativism
○ Prescriptions => principles
○ Outcomes => intentions
LAWRENCE KOHLBERG (1927-1987)
● Developed theory of 3 stages in moral development (based on responses to moral dilemmas)
PRECONVENTIONAL STAGE (CHILDHOOD)
● Morality of an action is primarily determined by its consequences for the actor
● Hedonism
CONVENTIONAL STAGE (ADOLESCENCE)
Morality of an action is primarily determined by the extent to which it conforms to social rules
Social consciousness: The view of others towards your actions
○ Laws, soc acceptance
POSTCONVENTIONAL STAGE (ADULTS)
● Morality of an action is determined by a set of general principles that reflect core values
●
●
CRITICISMS
● Reasoning may differ based on context
● Only studied in boys
● Moral thinking may/may not correlate w/ moral behaviour
○ Eg can think something is morally wrong but do it anyway
FEELING WHAT’S RIGHT
●
●
●
●
Moral decision making comes with feeling
Moral judgements may be the consequence (not cause) of emotional rxns
○ Moral intuitionist perspective: Perceptions of right/wrong are evol’nary emotional rxns
Children consider transgressions that cause others to be observably distressed
○ Is empathy in the brain? The brain responds to other people’s expressions of distress by causing us
the exp of distress
Trolley problem
ADOLESCENCE: MINDING THE GAP
●
●
Adolescence: Period of development that begins w/ onset of sexual maturity (11-14 y/o); lasts until
beginning of adulthood (18-21 y/o)
Puberty: Bodily changes assoc’d w/ sexual maturity
○ Primary sex characteristics: Bodily structures directly involved in reproduction
○ Secondary sex characteristics: Bodily structures that change dramatically w/ sexual maturity, but
not directly involved in reproduction
○ Brain changes
■ Connections btw temporal + parietal lobe made
■ Proliferation + pruning in prefrontal cortex
THE PROTRACTION OF ADOLESCENCE
●
●
●
Considerable variation exists in onset of puberty (btw genders, cultures, time periods/eras, etc)
○ Improved diet + health
○ Chemicals (esp those that mimic estrogen in females)
Age of puberty has decreased but age of adulthood responsibility has increased
○ Has this protraction caused adolescent turmoil?
~60% of pre-industrial societies don’t have a word for adolescence
○ Krobo girls and menstruation; “durbar” rite
SEXUALITY
●
●
Effects of puberty are different for M/F
○ Tends to be more positive for boys, more negative for girls
Choosing one’s sexuality is esp stressful during this period (esp if one doesn’t ID as heterosexual)
○ Biology (genes) may contribute to sexual orientation
●
■ Sibling + identical twin studies; brain studies on androgens
○ Environment may also contribute
Adolescent interest in sex often precedes knowledge abt it
○ Rate at which young Cdns engage in sex is dropping
○ Sex ed may be important to deter pregnancy + disease
SEXUAL ORIENTATION: A MATTER OF BIOLOGY
●
●
●
1-2% adolescents self-ID as gay/lesbian
4-7% report having had a same-sex relationship or attraction
Person’s sexual orientation determined by:
○ Genes
○ Size of cerebral hemispheres
○ Hormones
○ Gender non-conforming behavs
FROM PARENTS TO PEERS
●
●
Adolescence marks shift in emphasis from family relations to peer relations
○ Peer relationships evolve + “peel off”
○ Peer pressure forms but has less influence as we age
○ Form same-sex cliques that meet opposite-sex cliques => eventually form mixed-sex cliques
■ Pair off, get married, have kids, etc
Adolescents struggle for autonomy
ERIK ERIKSON (1902-1994)
●
●
Developed stages of human development that all humans go through
Adolescents go through the “ID vs role confusion” stage
AGES
KEY EVENT
CRISIS
POSITIVE RESOLUTION
Birth to 12-18 mos
Feeding
Trust vs mistrust
18 mos - 3 yrs
Toilet training
Autonomy vs
shame/doubt
3-6 yrs
Independence
Initiative vs guilt
6-12 yrs
School
Industry vs
inferiority
Child learns to do things well or correctly in
comparison to a standard or to others
12-18 yrs
Peer relationships
ID vs role
confusion
Adolescent develops sense of self in
relationship to others + to own internal
thoughts and desires
Who am I?
19-40 yrs
Love relationships
Intimacy vs
isolation
Child develops belief that environment can
be counted on to meet their basic
physiological + soc needs
Child learns what they can control +
develops sense of free will + corresponding
sense of regret and sorrow for inappropriate
use of self-control
Child learns to begin action, explore,
imagine, + feel remorse for actions
Person develops ability to give + receive love
Begins to make long-term commitment to
relationships
40-65 yrs
Parenting
Generativity vs
stagnation
Person develops interest in guiding
development of next generation
65 - death
Reflection on +
acceptance of one’s
life
Ego integrity vs
despair
Person develops sense of acceptance of life
as it was lived + importance of people and
relationships that the indiv developed over
the lifespan
ADULTHOOD: CHANGE WE CAN’T BELIEVE IN
●
Adulthood: Stage of development that begins around 18-21 yrs, ends in death
○ Changes: Physical, cognitive, emotional
CHANGING ABILITIES
●
●
Abilities + health peak in 20s; begin to deteriorate btw 26-30 yrs onward
Physical changes lead to psychological consequences (cognitive decline)
○ Older brains compensate by calling on other neural structures
○ Less bilateral asymmetry (in prefrontal cortex of older brains)
CHANGING GOALS
●
Socioemotional selectivity theory: Younger adults are oriented towards future-pertinent (useful) info;
older adults focus on (positive) emotional satisfaction in the present - perhaps bc of shortened futures
○ Older adults focus on + remember more positive exps + emotions
CHANGING ROLES
●
Psychological separation from parents begins in adulthood as young adults take on roles in marriage +
parenthood
○ Married ppl happier + have better health
○ Marital satisfaction ebbs/flows
○ Women tend to be less happy raising children
TAKEAWAYS
●
●
●
●
●
●
●
●
●
Definition of development
○ Phys, cog, soc changes
Mother’s voice can be heard from womb
Pruning
Maturation
Teratogens
Motor development
○ Start up + start off periods
○ Innate
Motor reflex (automatic response)
Continuity vs change
Kohlberg + moral development
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○ Dilemmas
○ Want to focus on explanation person gives
Piaget + cognitive development
Theory of mind: appreciation for indiv differences
Vygotsky + inner speech, scaffolding, theory of mind
Bowlby + attachment styles
Harlow: contact comfort
○ Higher security = more risk-taking + exploring
○ Romanian children w/ lower IQ
Authoritative vs authoritarian
Primary vs secondary sex characteristics
○ Know menopause
Telomeres
○ Capping on nerve cell; shortens w/ age => affects cognitive abilities
○ Biological marker for cognitive aging
○ Reduce shortening by reducing stress, exercising, good nutrition, new exps, learning skills
○ Neurogenesis: Creating new connections
Stroke as an example of a neurocognitive condition
WEEK 9 - CH 4: SENSATION AND
PERCEPTION
SENSATION AND PERCEPTION ARE DISTINCT ACTIVITIES
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Sensation: Simple stimulation of a sense organ
Perception: Organization, ID + interpretation of a sensation in order to form a mental representation
○ Can be influenced by experience + expectations
Take place at level of brain
Transduction: When many sensors in body convert physical signals from environment into encoded
neural signals sent to CNS
○ Conversion of energy into electrochemical signals
■ Vision: retina
● Snellen chart
● Occipital lobe (feature detector cells)
■ Auditory: inner ear; basilar membrane
● Measure w/ decibels
■ Olfactory: olfactory bulb
PSYCHOPHYSICS
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Perceptions differ btw people
Psychophysicists: Often measure minimum amount of stimulus needed for detection
Psychophysics: Methods that measure strength of a stimulus + observer’s sensitivity to that stimulus
○ Gustav Fechner (1801-1887)
MEASURING THRESHOLDS
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Absolute threshold: Minimal intensity needed to just barely detect a stimulus
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○ Usually ID on 50% of trials
○ As intensity gradually increases, we detect stimulation more frequently
Just noticeable difference (JND): Minimal change in a stimulus that can just barely be detected
○ Weber’s law: JND of a stimulus is a constant proportion despite variations in intensity
■ Eg add 2.5 lbs to bench press; add 1 tsp of sugar to drink
Subliminal messaging
○ Doesn’t quite meet threshold but still influences behaviour
○ Drive-in movies, shoes/handbags
SIGNAL DETECTION
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Sensory signals perceived among environmental “noise”
Signal detection theory: Response to a stimulus depends both on person’s sensitivity to stimulus in
presence of noise + person’s response criterion
○ Takes into account indiv perceptual sensitivity
○ Influenced by experience + expectations
MULTITASKING
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Perception is active; resources are limited
○ We use selective att’n to focus in on chosen stimuli in environment
Multitasking = paying att’n to more than 1 stimulus at the same time
○ Using phone while driving increases likelihood of accident by 4x (even w/ hands-free)
fMRI studies show decreases in brain areas during multitasking
People who frequently multitask often may have trouble focusing on 1 task
SENSORY ADAPTATION
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Sensory adaptation: Sensitivity to prolonged stimulation tends to decline over time as an organism
adapts to current conditions
○ Eg adapt to coldness of Polar Bear Plunge
○ Our sensory systems respond more strongly to changes in stimulation (vs constant stimulation)
A changing stimulus warrants a response
VISION I: THE EYES AND THE BRAIN CONVERT LIGHT
WAVES TO NEURAL SIGNALS
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Visual acuity: Ability to see fine detail
○ Vision 20/20 refers to measurement assoc’d w/ a Snellen chart
○ Smallest line of letters a typical person coan read from distance of 20 feet
Humans have photoreceptors in eyes that respond to wavelengths of light energy
○ Visible light: Portion of electromagnetic spectrum that is seen
■ Measure in nanometers (billionths of a meter)
● 400-700 nms
● Shorter rays purple/blue; longer waves red
PROPERTIES OF LIGHT WAVES
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Length: Determines hue (colour)
Intensity/amplitude: Determines brightness
Purity: Corresponds to saturation/richness of colour
THE EYE DETECTS AND FOCUSES LIGHT
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Light passes through cornea => (iris) => pupil => lens => retina
○ Accommodation: Process by which eye maintains clear image on retina
■ Lens bends light to focus on retina (where transduction occurs)
■ Ganglion cells, bipolar cells, rods + cones
○ Retina: Light-sensitive tissue lining back of eyeball
If accommodation occurs improperly, myopia (nearsightedness) or hyperopia (farsightnedness) may occur
LIGHT IS CONVERTED INTO NEURAL IMPULSES IN THE RETINA
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Photoreceptor cells in retina contain light-sensitive pigments that transduce light into neural impulses
○ Cones: Detect colour; operate under normal daylight conditions
■ Allow us to focus on fine detail
■ Fovea: Area of retina where vision is clearest; only cones (no rods)
○ Rods: Become active under low-light conditions for night vision
■ Light-dark adaption
Retina: Layers of cells in retina also including bipolar cells + retinal ganglion cells (in add’n to rod + cone
layers)
○ Outermost layer: Organize signals + send to brain
○ Middle layer: Bipolar cells convey neural messages from rods + cones to retinal ganglion cells
(RTC)
○ Innermost layer: Photoreceptor cells (rods + cones)
Blind spot: Location in visual field that produces no sensation on retina
○ Corresponding area of retina contains neither rods/cones => no mechanism to sense light
○ Optic chiasma
THE OPTIC NERVE CARRIES NEURAL IMPULSES TO THE BRAIN
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Neural impulses travel to brain along optic nerve
○ Half of axons code info in R visual vield; half code info in L visual field
Optic nerve travels from lateral geniculate nucleus (LGN) in thalamus
Visual signal travels to area V1 (area in occipital lobe containing primary visual cortex)
PERCEIVING COLOUR
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Colour: Our perception of wavelengths along visible light spectrum
○ Cones sensitive to red (long-wavelength), green (medium-wavelength) + blue (short-wavelength) light
■ All other colours = combos of these 3 wavelengths
○ Trichromatic colour representation: Pattern of respondoing across the 3 types of cones provides
a unique code for each colour
Colour deficiency/colour blindness
○ Compromises one of the cones
○ More common in males
Colour-opponent system: Pairs of visual neurons that work in opposition
○ Colour afterimage
■ Blue-yellow
■ Green-red
SEEING IN COLOUR
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We perceive spectrum of colour bc objects selectively absorb some wavelengths of lights + reflect others
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Colour perception corresponds to summed activity of the 3 types of cones
COLOUR MIXING
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Humans can perceives millions of shades of colour
○ Products of light’s wavelength + mixture of wavelengths a stimulus absorbs/reflects
When all visible wavelengths present => we see white
THE VISUAL BRAIN
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Streams of action potentials containing info encoded by retina travel to brain (via optic nerve) for further
processing
○ Lateral geniculate nucleus (LGN): Part of occipital lobe that contains primary visual cortex
■ Feature detectors in V1
2 distinct pathways (visual streams) project from occipital cortex to visual areas in other parts of brain
○ Ventral stream (“what”) to temporal lobe
○ Dorsal stream (“where”) to parietal lobe
Evidence of 2 distinct streams comes from PTs w/ brain injuries
○ Visual-form agnosia: Inability to recognize objects by sight
SINGLE-NEURON FEATURE DETECTORS
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Area V1 contains neurons that respond to specific orientations of edges
○ Eg fire more when bar pointing 45 deg R; less when vertical; not at all when 45 deg L
VISUAL STREAMING
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One interconnected visual system forms pathway that courses from occipital visual regions into lower
temporal lobe
○ Ventral pathway enables us to ID what we see
Other pathway travels from occipital lobe through upper regions of temporal lobe into parietal regions
○ Dorsal pathway allows us to locate objects, track movements + move in relation to them
VISION II: RECOGNIZING WHAT WE PERCEIVE
ATTENTION
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Binding problem: How features are linked together by brain so that we see unified objects in our visual
world (vs free-floating/miscombined features)
Parallel processing: Brain’s capacity to perform multiple activities at the same time
Errors in binding occur
○ Illusory conjunction: Perceptual mistake whereby features from multiple objects are incorrectly
combined
■ Eg shown a red “A” and blue “X” but report seeing blue “A” and red “X”
● Or misreport letter or colour
○ Feature-integration theory: Focused att’n is not required to detect indiv features that comprise a
stimulus, but is required to bind those indiv features together
■ Visual search
Binding process: Utilizes structures in ventral + esp dorsal stream (parietal lobe)
RECOGNIZING OBJECTS BY SIGHT
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Modular views vs distributed representation
Perceptual constancy: Even as aspects of sensory signals change, perception remains consistent
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Gestalt perceptual grouping rules
○ Grouping: Involves separating a figure from its (back)ground
■ Reversible figure-ground relationship
● Rubin’s vase: Classic reversible figure-ground illusion
○ Characterize many aspects of human perception
PRINCIPLES OF PERCEPTUAL ORGANIZATION
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Gestalt grouping rules: How features + regions of things fit together, as in:
○ Simplicity
○ Closure
○ Continuity
○ Similarity
○ Proximity
○ Common fate
■ Eg flashing lights that look like they’re moving
Brain is predisposed to impose order on incoming sensations
THEORIES OF OBJECT RECOGNITION
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Image-based object recognition theory: Objects are stored as templates
○ Template: Mental representation that can be directly compared to a viewed shape in retinal image
Parts-based object recognition theory: Brain deconstructs viewed objects into collection of parts
○ Geons: Geometric elements that can be combined to make objects
PERCEIVING DEPTH AND SIZE
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Monocular depth cues: Aspects of a scene that yield info abt depth when viewed w/ only 1 eye
○ Relative size; familiar size; linear perspective; texture gradient; interposition; relative height
Binocular depth cues: Difference in retinal images of the 2 eyes that provides info abt depth
○ Binocular disparity
Illusions of depth + size
○ Ames room
PERCEIVING MOTION AND CHANGE
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To sense motion, visual system must encode info abt both space + time
○ MT in dorsal stream (temporal lobe)
Illusions in motion
○ Waterfall illusion (opponent process); apparent motion
■ Perception of movement as a result of alternating signals appearing in rapid succession in
different locations
○ Both colour + motion reception rely partially on opponent processing
Sometimes we fail to focus attention on a changed object
○ Change blindness: Failure to detect changes to visual details of a scene
○ Inattentional blindness: Failure to perceive objects that are not the focus of attention
AUDITION: MORE THAN MEETS THE EAR
SENSING SOUND
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Hearing: Detection of sound waves; changes in air pressure unfolding over time
○ Pure tones = simple sound waves
Sound waves involve qualities of:
○ Frequency (Pitch: how high/low a sound is)
○ Amplitude (Loudness; sound’s intensity)
■ Anything above 80 dB is harmful
○ Timbre: Listener’s exp of sound quality or resonance
HAVING TWO EARS HELPS US LOCALIZE SOUND SOURCES
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Ears placed on opposite sides of head enable stereophonic hearing
Sound heard as louder when source is closer to ear
Direction of sound source can be determined from timing
○ Sound waves arriving at/near ear sooner indicate direction of source
○ Head shadow effect
ANATOMY
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Outer ear: Collects sound waves
Middle ear: Transmits vibrations
○ Ossicles: malleus, incus, stapes
Inner ear: Transduction into neural impulses
○ Transduction; involves several structures
○ Cochlea: Fluid-filled tube (organ of auditory transduction)
○ Basilar membrane: Structure in inner ear that undulates when vibrations from ossicles reach
cochlear fluid
○ Hair cells: Specialized auditory receptor neurons embedded in basilar membrane
AUDITORY NERVE CARRIES NEURAL IMPULSES TO THE BRAIN
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Auditory cortex composed of 2 distinct streams
a. Spatial (“where”) auditory features locate source of a sound
■ Back/caudal auditory cortex
b. Nonspatial (“what”) auditory features locate temporal aspects of a sound
■ Lower/ventral auditory cortex
Area A1: Portion of temporal lobe that contains primary auditory cortex
PERCEIVING PITCH
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Encoding of sound occurs in 2 ways
a. Place code: Cochlea encodes different frequencies at different locations along basilar membrane
■ Low frequencies fire at apex; high frequencies fire at base
■ Eg distinguish middle C on a piano
b. Temporal code: Cochlea registers low frequencies via firing rate of action potentials entering
auditory nerve
HEARING LOSS
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2 main causes
Conductive hearing loss: Damage to eardrum or ossicles
Sensorineural hearing loss: Damage to cochlea, hair cells or auditory nerve
■ Eg German measles; continual exposure to loud noise
Cochlear implant: Electronic device that replaces function of hair cells
○ May help sensorineural hearing loss
○ May assist in normal language development
○ Bypass auditory nerve; controversial
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MUSIC TRAINING: WORTH THE TIME
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Study of elementary school musicians
○ Structural differences in auditory and motor areas + improved skills in these areas
Study of 8 y/o musicians
○ Enhanced performance in musical + speech perception tasks
Neural changes persist into young adulthood
THE BODY SENSES: MORE THAN SKIN DEEP
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Body senses = somatosenses
Haptic perception: Active exploration of environment by touching + grasping objects w/ our hands
SENSING TOUCH
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4 types of receptors for touch
○ Hot; cold; pain; pressure
○ Respond to pain, pressure, texture, pattern, vibration
○ Thermoreceptors respond to temperature changes
Contralateral representation
Cortical space allocation related to sensitivity
“What/where” pathways
ANATOMY(?)
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Specialized sensory neurons form distinct groups of haptic receptors that detect pressure, temperature +
vibrations against skin
Touch receptors respond to stimulation within receptive fields + long axons enter brain via spinal or
cranial nerves
Pain receptors populate all body tissues that feel pain
○ Distributed around bones + within muscles and internal organs + under skin surface
SENSING PAIN
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Pain indicates damage/potential damage to body
○ Tissue damaged transduced by pain receptors
■ A-delta fibres: Quick, sharp pain
● Diminish by giving person control, provide strategies to gain control, soc support
■ C fibres: Long, dull pain
2 pain pathways
○ One sends “where” info to somatosensory cortex
○ Other sends motivational + emotional info to hypothalamus, amygdala + frontal lobe
PERCEIVING PAIN
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Referred pain: Feeling of pain when sensory info from internal + external areas converges on same nerve
cells in spinal cord
○ Origin of pain gets referred to another part of the body
Pain intensity is subjective
○ Gate-control theory: Signals arriving from pain receptors in body can be stopped (gated) by
interneurons in spinal cord via feedback (PAG) from 2 directions
■ Melzack & Wall, 1965
■ Endorphins can buffer pain exp
○ Some recent evidence indicates ethnic differences in subjective pain intensity
Phantom pain: Pain that feels like it's coming from a body part that's no longer there
○ Mirror therapy
BODY POSITION, MOVEMENT, AND BALANCE
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Sensory receptors provide info we need to perceive position + movement of our limbes, head + body
Vestibular system: 3 fluid-filled semicircular canals + adjacent organs located next to cochlea in each
inner ear
○ Used w/ visual feedback to maintain balance
THE CHEMICAL SENSES: ADDING FLAVOUR
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Chemical senses include:
○ Olfaction (smell)
○ Gustation (taste)
○ Stimuli borne in air for smell + soluble (in saliva) for taste
Together, smell + taste produce perceptual sense of flavour
SENSE OF SMELL
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Odorant molecules travel through nose to olfactory epithelium => bind to receptors
○ Olfactory receptor neurons (ORNs): Receptor cells that initiate sense of smell
Groups of ORNs send axons to olfactory bulb + converge on glomeruli
○ Olfactory bulb: Brain structure located above nasal cavity beneath frontal lobes
PERCEIVING SMELL
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Smell is intimately related to emotional + soc behav
○ Object-centered approach: Info abt ID of odor object is quickly accessed from memory + triggers
emotional response
○ Valence-centered approach: Emotional response comes first + provides basis for determining ID
of odor
Chemical odors may affect sexual behaviour
○ Pheromones: Biochemical odorants emitted by other members of its species that can affect an
animal’s behav or psychology
■ Scents given off from sweat; mating power
● Detect strength of immune system?
■ PET study using testosterone-based odor found significant activation in hypothalamus for hetero
women + homo men, but not hetero men
SENSE OF TASTE
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One of primary responsibilities of taste = ID things that are bad for you
○ Some aspects of taste perception are genetic, others learned
Tongue covered w/ thousands of bumps (papillae) which contain taste buds (house taste receptor cells)
○ Taste buds: Organ of taste transduction
4 (5?) types of taste receptor cells whose tips (microvilli) react to tastant molecules
○ Salt, sour, bitter, sweet, umami
PERCEIVING TASTE
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Flavour: Combination of smell + taste experiences
Individual differences in taste perception
○ Tasters, non-tasters, supertasters
TAKEAWAYS
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Light-dark adaptation
Women have stronger sensory systems (on avg); can vary w/ cycle (estrogen levels; strongest at peak)
Pheromones
Synesthesia (eg hear colours)
Tinnitus
Bottom-up vs top-down processing
○ Bottom-up: stimulus goes from sensory system to brain => decipher what you’re experiencing
■ Info processing
○ Top-down: expectation influences response; based on person’s perception
■ Eg repeat “stop” before answering “what do you do when you get to a green light?”
Transduction
Psychophysics (study of thresholds)
○ Physical exp one has (vs psych expectations)
○ Absolute threshold (50%); Weber’s law (JND)
Subliminal suggestion
Sensory adaptation
Perceptual set (functional fixedness?)
○ Mental predisposition to influence how a person thinks about something
Vision pathway
Electromagnetic spectrum
Colour deficiency in males
Gestalt grouping; Rubin vase
Depth perception
Kinaesthetics: limits of range of motion
○ Based on proprioceptors
Nature vs nurture
○ Locke = nature; tabula rasa
○ Kant = nature
Anything above 80 dB is harmful
WEEK 10 - CH 5: CONSCIOUSNESS
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Consciousness: Person’s subjective exp of the world + mind
Phenomenology: How things seem to the conscious person
THE MYSTERIES OF CONSCIOUSNESS
PROBLEM OF OTHER MINDS
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Problem of other minds: Fundamental difficulty we have in perceiving the consciousness of others
○ People judge minds according to capacity for exp + capacity for agency
THE MIND-BODY PROBLEM
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Seat of the Soul (Descartes)
○ Cartesian dualism (thought mind + body were separate)
○ Seat of the soul + consciousness might reside in pineal gland
located in ventricles of brain
○ Original drawing (1662) shows pineal gland nicely situated for
a soul, right in middle of brain
THE TIMING OF CONSCIOUS WILL
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Benjamin Libet
○ How long does it take for thoughts to result in an output?
Participants asked to move fingers at will while watching dot move around clock face => mark moment at
which action was consciously willed
EEG sensors timed onset of brain activation; EMG sensors timed muscle movement
THE NATURE OF CONSCIOUSNESS
FOUR BASIC PROPERTIES
PROPERTY
Intentionality
Unity
DEFINITION
Being directed towards an object
Resistance to division
● Integrating info from senses to form a whole
Selectivity
Capacity to include some objects, but not others
● Dichotic listening: Task where people wearing headphones hear different messages
presented to each ear
● Cocktail party phenomenon: People tune in one message even while they filter out
others nearby
Transience
Has tendency to change
THE NECKER CUBE
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Has property of reversible perspective (can bring 1 or other of its 2 square faces
to the front in your mind’s eye)
Stream of consciousness flows even when target is a constant object
LEVELS OF CONSCIOUSNESS
LEVEL OF CONSCIOUSNESS
Minimal consciousness
DEFINITION
Low-level kind of sensory awareness + responsiveness
Occurs when mind inputs sensations + may output behaviour
Full consciousness
Consciousness in which you know + can report your mental state
Self-consciousness
Distinct level of consciousness in which person’s att’n is drawn to self as
an object
HOT SCIENCE: COMA AND DISORDERS OF CONSCIOUSNESS
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Coma: State of prolonged unconsciousness that can be caused by many problems (eg head injury, stroke)
a. Vegetative state; PTs don’t produce behaviour reliably in response to external stimuli
b. Minimally conscious state PTs can respond reliably, but inconsistently
c. Locked-in syndrome: PTs have full awareness but can’t respond to any external stimuli
■ Not a disorder of consciousness
■ Brain imaging helpful in diagnosis
Glasgow coma scale
CONSCIOUS CONTENTS
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People can report on their conscious exps using the experience-sampling technique
○ fMRI research on daydreaming shows widespread pattern of brain activation (default network)
DAY DREAMS: THE BRAIN IS ALWAYS ACTIVE
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Daydreaming: State of consciousness in which a seemingly purposeless flow of thought comes to mind
○ Brain is active during daydreaming but has no specific task at hand
Activation of default mode network
EFFORTS TO SUPPRESS CURRENT CONCERNS CAN BACKFIRE
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Mental control: Attempt to change conscious states of mind
○ Ironic processes of mental control: Mental process that can produce ironic errors bc monitoring
for errors can itself produce them
Thought suppression: Conscious avoidance of a thought
○ Rebound effect of thought suppression: Tendency of a thought to return to consciousness w/
greater frequency following suppression
THE UNCONSCIOUS MIND
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Unconscious processing can help or hurt decision making
FREUDIAN UNCONSCIOUS
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Dynamic unconscious: Active system encompassing a lifetime of hidden memories, person’s deepest
instincts + desires, and person’s inner struggle to control these forces
Repression: Mental processes that remove unacceptable thoughts + memories from consciousness +
keeps them in the unconscious
A MODERN VIEW OF THE COGNITIVE UNCONSCIOUS
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Cognitive unconscious: All mental processes that give rise to a person’s thoughts, choices, emotions +
behav even though they are not exp’d by the person
Subliminal perception: A thought/behaviour that is influenced by stimuli that a person cannot
consciously report perceiving
○ Controversial
SLEEP AND DREAMING: GOOD NIGHT, MIND
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Altered state of consciousness: Form of exp that departs from normal subjective exp of the world + mind
Can be accompanied by:
○ Changes in thinking
○ Disturbances in sense of time
○ Feelings of loss of control
○ Changes in emotional expression
○ Alterations in body image + sense of self
○ Perceptual distortions
○ Changes in meaning or significance
SLEEP
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Hypnagogic state: Presleep consciousness
○ Falling down to a lower level of brain activity (like a daze)
Hypnic jerk: Sudden quiver or sensation of dropping (eg missing a step)
Hypnopompic state: Postsleep consciousness
SLEEP CYCLE
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Circadian rhythm: Naturally occurring 24-hr cycle
○ Mess up by travel, shift work
○ Core temperature drops at night (37 => 35.5 - 36 deg)
○ Poor sleep can cause weight gain (more ghrelin, less leptin)
5 stages of sleep: Stages 1-4 + REM sleep
○ Brain shows EEG changes in beta, alpha, theta + delta waves (cycles per second)
■ Beta: 13
■ Alpha: 8-13
■ Theta: 4-8
■ Delta: <4
○ REM sleep: Sleep stage characterized by rapid eye movements + high level of brain activity
■ Electrooculograph (EOG): Instrument that measures eye movements
■ Dreaming occurs most often in this stage
■ Body is immobilized
● Spine is not firing the muscles while brain is going crazy
● Paradoxical sleep (beta wave; brain activity looks like you’re awake)
■ Mess up w/ alcohol, sleep deprivation, tranquilizers (eg benzodiazepines)
● Memories deteriorate w/o sleep
Each stage approx 90 min
REM occurs at the end of each cycle + gets longer as night progresses
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SLEEP DISORDERS
SLEEP DISORDER
DEFINITION
Insomnia
Difficulty falling or staying asleep
Sleep apnea
Person stops breathing for brief periods while asleep
Somnambulism (sleepwalking)
Person arises + walks around during sleep (usually during slow-wave sleep)
Narcolepsy
Sudden attacks of sleep during waking activities
Sleep paralysis
Exp of waking up unable to move
Night terrors (sleep terrors)
Abrupt awakenings w/ panic + intense emotional arousal
Occurs in nREM sleep
DREAMS
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Dream consciousness
5 major characteristics that distinguish dreaming from waking consciousness
a. Intense emotion
b. Illogical thought
c. Meaningful sensation
d. Uncritical acceptance
e. Difficulty remembering dream on waking
DREAM THEORIES
FREUD’S VIEW: DREAMS HOLD MEANING
● Manifest content: Dream’s apparent topic or superficial meaning
○ Symbolic of latent content
○ Eg dream about horse chasing you
● Latent content: Dream’s true underlying meaning
○ Eg horse is manifestation about abusive father
ACTIVATION-SYNTHESIS MODEL
● Dreams produced when brain attempts to make sense of activations that occur randomly during sleep
● fMRI scans of brains during dreaming show brain areas involved in emotional + visual imagery, but not
prefrontal cortex (planning)
DRUGS AND CONSCIOUSNESS: ARTIFICIAL INSPIRATION
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Psychoactive drugs: Chemicals that influence consciousness or behaviour by altering brain’s chemical
message system
○ Agonists increase activity of a neurotransmitter
○ Antagonists decrease activity of a neurotransmitter
i.
Prevent binding of neurotransmitters on postsynaptic neuron
ii.
Inhibit reuptake
iii.
Enhance binding + transmission
DRUG USE AND ABUSE
DANGERS OF ADDICTION
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Drug tolerance: Tendency for larger doses of a drug to be required over time to achieve same effect
Physical dependence: Unpleasant physiological symptoms accompanying withdrawal from drug use
Psychological dependence: Desire to return to drug use even when physical symptoms are gone
Drug withdrawal symptoms: Include physical dependence + psychological dependence
Drug addiction has different definitions
○ Defined as disorder when it starts to mess up your functioning
■ Substance use disorder; substance abuse disorder
● Most people who use drugs do not become addicted
● What’s considered “addictive” can change (w/ times + cultures)
TYPES OF PSYCHOACTIVE DRUGS
DEPRESSANTS
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Depressants: Substances that reduce activity of CNS
○ Eg barbiturates + benzodiazepines prescribed to treat anxiety or sleep problems
Alcohol = “king” of depressants
○ Expectancy theory: Idea that alcohol effects can be produced by people’s expectations of how
alcohol will influence them in particular situations
○ Balanced placebo design: Study design in which behav is observed following the
presence/absence of an actual stimulus + also following presence/absence of a placebo stimulus
■ Test of expectancy theory
○ Alcohol myopia: Condition that results when alcohol hampers attention => people respond in
simple ways to complex situations
STIMULANTS
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Stimulants: Substances that excite CNS => heightens arousal + activity levels
○ Eg caffeine, amphetamines, nicotine, cocaine, modafinil, ecstacy (MDMA)
Elicit euphoria + confidence/motivation
○ Increase DA + NE in brain
NARCOTICS
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Narcotics (opiates): Highly addictive drugs derived from opium that relieve pain
○ Eg heroin, morphine, methadone, codeine
○ Drug properties closely related to endorphins
HALLUCINOGENS
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Hallucinogens: Drugs that alter sensation + perception; often cause visual + auditory hallucinations
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○ Eg LSD/acid, mescaline, psilocybin, PCP, ketamine
Effects are dramatic + unpredictable
MARIJUANA
Marijuana: Leaves + buds of hemp plant that produce intoxication that is mildly hallucinogenic
Drug affects judgement + short-term memory; impairs motor skills + coordination
○ Medicinal uses remain controversial
● Considered a gateway drug (along w/ alcohol + tobacco)
○ Gateway drug: Drug whose use increases risk of subsequent use of more harmful drugs
■ 44% of Cdns report using marijuana at least once
○ Harm reduction approach: Response to high-risk behave that focuses on reducing harm such
behavs have on people’s lives
■ Medicinal use legal; recreational use illegal
● Stays in body longer bc fat-soluble
OTHER VOICES: POT SHOULD BE LEGALIZED, REGULATED, AND SOLID LIKE ALCOHOL
● CAD’s largest MH + addiction treatment and research centre has called for legalization of marijuana but
w/ strict controls
○ Legalization w/ control may reduce harm assoc’d w/ its use
○ Controls over quant/qual would be exerted by gov’t to keep cannabis supply safe + regulated
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HYPNOSIS: OPEN TO SUGGESTION
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Hypnosis: Altered state of consciousness characterized by suggestibility + feeling that one’s actions are
occurring involuntarily
○ Lead people to expect that certain things will happen that are outside their conscious will
■ Eg reduce pain, stop addictions
○ Susceptibility varies greatly; subject to agreeableness
Dissociating from stimuli around you => go to internal state of conscious awareness
HYPNOTIC EFFECTS
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Claims of supernatural feats + memory recollection under hypnosis are controversial
Posthypnotic amnesia: Failure to retrieve memories following hypnotic suggestions
Hypnotic analgesia: Reduction of pain through hypnosis in people who are susceptible to hypnosis
○ Stronger than acupuncture, meds
PET scans show brain activation of hypnotic hallucination to be similar to real perception
TAKEAWAYS
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ESP (extrasensory perception)
○ Telepathy (mind-to-mind communication)
○ Precognition (prediction of future events)
○ Clairvoyance (awareness of remote events)
Parapsychology (study of ESP)
○ Research is super difficult
Psychokinesis (movement of matter w/o touching it; use mental energy)
Definition of consciousness
What does a cognitive neuroscientist do? See Libet
Parallel processing
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Selective attention; cocktail party effect
Circadian rhythm; sleep stuff
Sleep stages and cycles
Sleep deprivation effects (weight gain)
○ Animals sleep a lot
Drugs, withdrawal
WEEK 12 - CH 6: MEMORY
WHAT IS MEMORY?
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Memory: Ability to store + retrieve info over time
○ Encoding: Process by which we transform what we perceive, think, or feel into an enduring
memory
■ Getting information into memory
○ Storage: Process of maintaining info in memory over time
■ Containers: sensory, short-term, long-term
○ Retrieval: Process of bringing to mind info that has been previously encoded + stored
■ Getting info out of memory
Gender differences
○ Males encode on R hemisphere; females on L hemisphere (remember more detail)
Aging differences
○ Eg Alzheimer’s
Law and recall
○ Leading questions can influence our responses to questions
ENCODING: TRANSFORMING PERCEPTIONS INTO
MEMORIES
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Memories are constructed
○ Combine info we already have w/ new incoming info
3 majors way to encode:
ENCODING PROCESS
Semantic encoding
DESCRIPTION
Process of actively relating new info in a meaningful way to knowledge that is
already in memory
Visual imagery encoding
Process of storing new info by converting it into mental pictures
Organizational encoding
Process of categorizing info according to the relationships among a series of items
Easier to remember things when organized into categories
ENCODING OF SURVIVAL-RELATED INFORMATION
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Based on evol’nary theories of natural selection, memory mechanisms that help us survive should be
passed down
○ Eg more likely to remember a snake or tiger, vs a tree
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An experiment assigned 3 different encoding tasks to participants (survival-encoding condition; movingencoding condition; pleasantness-encoding condition)
○ Survival encoding yielded better memory (in free recall)
■ Perhaps drawing from elaborative, visual imagery + organizational coding
STORAGE: MAINTAINING MEMORIES OVER TIME
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Sensory storage: Storage that holds sensory info for a few seconds or less
○ Iconic memory: Fast-decaying store of visual info
■ Iconic memory test (letter grid flashed for 1/20th of a second; ask to recall indiv letters)
● Ebbinghaus
○ Echoic memory: Fast-decaying store of auditory info
■ Info more strongly encoded this way (vs iconic)
○ Haptic memory: Fast- decaying storage of tactile info
Unattended info is lost
SHORT-TERM STORAGE AND WORKING MEMORY
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Short-term memory (STM): Storage that holds nonsensory info for more than a few seconds but less than
a minute; can hold about 7 items
○ Rehearsal: Process of keeping info in STM by mentally repeating it
■ STM fades quickly w/o rehearsal
○ Chunking: Combing small pieces of info into larger clusters/chunks that are more easily held in
STM
■ Eg breaking down phone numbers; chess players break down info into smaller compartments
■ Utility of mnemonics
Working memory: STM storage that actively maintains info
○ Stores + manipulates info
○ Includes 2 subsystems whose info is coded by the episodic buffer:
■ Visio-spatial sketchpad
● Visual; spatial; haptic
■ Phonological loop
● Speech; sign + lip reading; music + sound
○ Central executive coordinates all the info
Effortful processing vs automatic processing
Research examining link btw working memory training + cognitive functioning
○ Improvements seen in working memory + math tasks
LONG-TERM STORAGE
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Long-term memory (LTM): Storage that holds info for hours/days/weeks/years
○ No known capacity limits
○ We continue to learn our entire lives
People can recall items from long-term memory even if they haven’t thought of them for years
○ Even 50 years after grad, people can accurately recognize ~90% of their HS classmates from yearbook
photographs
THE HIPPOCAMPUS
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Hippocampus = critical as an “index” for LTM
○ Case of HM who had his hippocampus (temporal lobe) removed to prevent seizures
■ Intended to sever his corpus callosum to stop seizure from spreading sides
■ Had STM, but no LTM
Anterograde amnesia: Inability to transfer new info from short-term store into long-term store
○ Can’t process new info
○ Eg can’t remember things after an accident
Retrograde amnesia: Inability to retrieve info that was acquired before a particular date
○ Usually date of an injury or operation
Consolidation: Process by which memories become stable in the brain
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○ Neural storage into long-term memory
Reconsolidation: Memories can become vulnerable to disruption when recalled, requiring them to
become consolidated again
HOT SCIENCE: SLEEP ON IT
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Sleep plays an active role in memory consolidation (not just in prevention of interference)
EXPERIMENT: Groups given a picture-location association after sleeping or remaining awake
○ Both groups spent same amount of time sleeping/awake
○ Sleep group recalled more
Sleep contributes to memory consolidation by increasing hippocampal involvement in recall a couple days
later => facilitate interxn of hippocampus w/ frontal lobe so that hippocampus is later less centrally
involved in recall
Study before bed!
MEMORIES, NEURONS, AND SYNAPSES
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Research suggests that connections (synapses) btw neurons (specifically in hippocampus) strengthen
memories
○ Sea slug Aplysia (Kandel)
■ Flashed lights on them; discovered withdrawal reflex
Long-term potentiation (LTP): Process whereby comm’n across synapse btw neurons strengthens the
connection, making further comm’n easier
○ NMDA receptor: Receptor site on hippocampus that influences flow of info btw neurons by
controlling the initiation of LTP
RETRIEVAL: BRINGING MEMORIES TO MIND
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Info is sometimes available in memory even when not accessible
○ Retrieval cues: External info assoc’d w/ stored info that helps bring that info to mind
■ Can be sensory, visual, etc
External context provides cues
○ Encoding specificity principle: Idea that a retrieval cue can serve as an effective reminder when it
helps recreate the specific way in which info was initially encoded
Inner states provide cues
○ State-dependent principle: Tendency for info to be better recalled when the person is in the same
state during encoding + retrieval
■ Eg home court advantage; scent of coffee in an exam room
Matching encoding + retrieval contexts improves recall
○ Transfer-appropriate processing: Memory is likely to transfer from 1 situation to another when
coding + retrieval contexts of the situations match
CONSEQUENCES OF RETRIEVAL
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Act of retrieval can strengthen a retrieved memory (esp long term); can also cause forgetting
Retrieval-induced forgetting: Process by which retrieving an item from long-term memory impairs
subsequent recall of related items
○ Frontal lobe suppresses competing info
Regions in L frontal lobe show activity when people try to retrieve info, while successful retrieval shows
hippocampal activation
CHILDHOOD AMNESIA IN WESTERN AND EASTERN CULTURES?
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In Western cultures (on avg), an indiv’s first memory dates to about 3-3.5 y/o
○ Women report slightly earlier first memories than men
First memories of 14 y/o Chinese children came from a later age than 14 y/o CDNs
Onset of childhood amnesia in Chinese 14 y/o’s identical to that of North American adults
First memories seen later in cultures that place less emphasis on talking about the past => culture has
significant impact on even our earliest memories
Kids don't remember things before age 3 before hippocampus hasn't matured yet
FORMS OF LONG-TERM MEMORY: MORE THAN ONE
KIND
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Explicit memory: Act of consciously/intentionally retrieving past exps
○ Eg facts, dates
Implicit memory: Influence of past exps on later behav, even w/o an effort to remember them or
awareness of the recollection
○ Eg fear of snakes; how to ride a bike
EXPLICIT MEMORY
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Semantic memory: Network of assoc’d facts + concepts that make up our general knowledge of the world
○ Eg remember why we observe Remembrance Day
Episodic memory: Collection of past personal exps that occurred at a particular time + place
○ Involves mental time travel
○ Contributes to imagination + creativity
IMPLICIT MEMORY
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Procedural memory: Gradual acquisition of skills as a result of practice or “knowing how” to do things
○ Karl Lashley + lesioning rats’ brains to try to locate memory in the brain
Priming: Enhanced ability to think of a stimulus as a result of a recent exposure to the stimulus
○ Less cortical activation (perceptual + conceptual priming)
○ Priming makes some info more accessible; saves processing time for brain
○ Associated w/ reduced activity in various regions of cortex that are activated when performing
unprimed tasks
Procedural memory + priming do not rely on hippocampus
Resistant to interference
COLLABORATIVE MEMORY: SOCIAL INFLUENCES ON REMEMBERING
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Collaborative memory: How people share in groups
Remembering serves important soc functions
○ Sharing memories w/ others can strengthen them, but can also produce retrieval-induced
forgetting
○ Social loafing
○ Transactive memory
IS GOOGLE HURTING OUR MEMORIES?
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Searching occurs more on Google than in our memories (Sparrow et al.)
People use computers as an efficient way to help them remember facts, while relying on personal
memories to recall where these facts could be found
Just as collaborative memory w/ other people has helpful + harmful effects, so does collaborative
remembering w/ computers
MEMORY FAILURES: THE SEVEN “SINS” OF MEMORY
1. Transience: Forgetting what occurs, over time
○ Memory fades more quickly at first, then more slowly over time
i.
Lose synaptic connections
○ Involves switch from specific to more general memories
○ Retroactive interference: Situations in which info learned later impairs memory for info acquired
earlier
i.
Eg trying to recall old password
○ Proactive interference: Situations in which info learned earlier impairs memory for info acquired
later
i.
Eg taking multiple courses at school
2. Absentmindedness: Lapse in attention that results in memory failure
○ Less activity in frontal lobe when attention is divided
○ Prospective memory: Remembering to do things in the future
3. Blocking: Failure to retrieve info that is available in memory even though you are trying to produce it
○ AKA tip-of-the-tongue phenomenon
○ Peterson/Peterson technique (remember things will asking them to do a task, eg count backwards
in intervals of 3)
4. Memory misattribution: Assigning a recollection/idea to the wrong source
○ Frontal lobe intimately involved
○ Source memory: Recall of when, where + how info was acquired
○ False recognition: Feeling of familiarity about something that hasn’t been encountered before
i.
Same brain activation as true recognition (incl. hippocampus)
○ Dangerous misattributions
i.
Case of man wrongly convicted of 1st-deg murder due to eyewitness misattribution
ii.
Eyewitness testimony is relied on heavily in criminal trials, yet often inaccurate
● Criminal lineup procedures misleading
iii.
New developments in eyewitness procedures (at advice of psychologists) will be
influential)
5. Suggestibility: Tendency to incorporate misleading info from external sources into personal recollections
○ People can develop false memories in response to suggestions
i.
Eg effect of saying a car was “smashed” vs “hit”
○ Cases of recovered memories of abuse?
6. Bias: Distorting influences of present knowledge, beliefs + feelings on recollection of previous exps
○ Consistency bias: Tendency to reconstruct the past to fit the present
○ Change bias: Tendency to exaggerate differences btw what we feel/believe now + what we
felt/believed in the past
○ Egocentric bias: Tendency to exaggerate the change btw present/past in order to make ourselves
look good in retrospect
i.
Self-serving bias
7. Persistence: Intrusive recollection of events that we wish we could forget
○ Often occurs after disturbing/traumatic events
i.
PTSD
ii.
Freud + repression
○ Emotional exps better remembered than unemotional ones
○ Flashbulb memories: Detailed recollections of when/where we heard abt shocking events
i.
Amygdala involved in emotional memory
● Can remember stuff if you remove the amygdala but will be flat; items remembered
equally (eg death of mother vs where you lost your keys)
● Will remember things more during stress responses(?)
VICES OR VIRTUES?
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Each of the 7 sins can cause trouble, but can be adaptive
Sins should be viewed as the costs we pay for benefits of a memory that works well most of the time
TAKEAWAYS
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Memory recall
○ Eg if you were in a car accident and wanted to remember what the other party was doing
Ebbinghaus: father of memory
○ Nonsense syllables + recall; how much time could pass before you can’t recall anything?
Encoding, storage, retrieval
Sensory storage, STM (+ working memory), LTM
○ LTM is limitless
Effortful processing: need more effort to remember more complex/demanding things
Implicit + explicit memory
○ Hippocampus + explicit memory
■ L damage + verbal; R damage + visual
○ Cerebellum (bicycle riding; balance) + implicit memory
Peterson Brown technique: count backwards in 3s to block rehearsal
Mnemonic (eg acronyms, ROY G. BIV)
Memory is spread over a brain; not localized
○ Lashley
Consolidation
Quality of sleep
Infantile amnesia + hippocampus
Stress hormones (epinephrine of adrenal glands help w/ consolidation in hippocampus)
○ Cortisol increases glucose => more energy to process info
Flashbulb memory + emotion
Context memory (home court advantage)
Types of amnesia
Laurier is on the $5 bill
Types of interference
Fallibility of memory
Propranolol (drug) dampens memory
CREB = protein that enhances memory
WEEK 13 - CH 7: LEARNING
WHAT IS LEARNING?
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Learning: Acquisition (from exp) of new knowledge/skills/responses that result in a relatively permanent
change in the state of the learner
○ Eg you never forget how to ride a bike (don’t have to think abt it)
Habituation: General process where repeated/prolonged exposure to a stimulus results in a gradual
reduction in responding
○ How long will you look at a stimulus before you look away for new information?
Sensitization: Simple form of learning where presentation of a stimulus elads to an increased response to
a later stimulus
CLASSICAL CONDITIONING: ONE THING LEADS TO
ANOTHER
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Classical conditioning: When a neutral stimulus produces a response after being paired w/ a stimulus that
naturally produces a response
○ Learning takes place fairly rapidly + levels off as stable responding develops
○ Sympathetic firing (involuntary) to paired assoc’n
○ Ivan Pavlov
■ Dogs salivating to bell
COMPONENT
DEFINITION
Unconditioned stimulus (US)
Something that reliably produces a naturally occurring reaction in an
organism
Unconditioned response (UR)
Reflexive reaction reliably produced by an unconditioned stimulus
Neutral stimulus
Stimulus that at first elicits no response
Conditioned stimulus (CS)
Stimulus that is initially neutral + produces a reliable response in an organism
Conditioned response (CR)
Reaction that resembles an unconditioned response, but is produced by a
conditioned stimulus
ACQUISITION, EXTINCTION, AND SPONTANEOUS RECOVERY
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Acquisition: Phase of classical conditioning when CS + US are presented together
○ Same as learning
Extinction: Gradual elimination of a learned response that occurs when US is no longer presented
○ CS no longer produces CR
■ CR diminishes quickly until no longer occurs
○ Eg dog no longer salivates to bell
Second-order conditioning: Conditioning where CS is paired w/ a stimulus that became assoc’d w/ the US
in an earlier procedure
○ Eg bell causes dog to salivate to a black square (instead of meat)
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Spontaneous recovery: Tendency of a learned behaviour to recover from extinction after a rest period
GENERALIZATION AND DISCRIMINATION
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Generalization: Process by which CR is observed, even though CS is slightly different from original in
acquisition
○ Eg metronome produces same response as bell; Little Albert gets scared of other white things
Discrimination: Capacity to distinguish btw similar but distinct stimuli
○ Only 1 CS produces the CR
○ Eg dog salivates only to Middle C
CONDITIONED EMOTIONAL RESPONSES: LITTLE ALBERT
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Watson & Rayner (1920) conditioned 9 mos old baby to fear a white rat
○ Struck steel bar when baby presented w/ rat
Baby showed stimulus generalization
THE COGNITIVE ELEMENTS OF CLASSICAL CONDITIONING
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Rescorla-Wagner model: Suggests that classical conditioning only occurs when organism has learned to
set up an expectation
○ CS serves to set up an expectation => leads to array of behavs assoc’d w/ presence of CS
■ Eg CS (bell) => expectation of food => salivation, tail wagging, looking for food, begging
THE NEURAL ELEMENTS OF CLASSICAL CONDITIONING
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Eyeblinking conditioning research argues that classical conditioning draws upon implicit but not explicit
memory (based on awareness of CS + US)
○ Delay + trace conditioning in amnesiacs
○ Impaired reality testing in schizophrenics
Experiments w/ rabbits in eyeblink conditioning implicate cerebellum in delay + trace conditioning
○ Hippocampus also implicated in trace conditioning (but not as much in delay conditioning)
○ Amygdala (central nucleus) responsible for fear conditioning
■ Behav’l + physiological (ANS) responses)
THE EVOLUTIONARY ELEMENTS OF CLASSICAL CONDITIONING
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Adaptive behaviours allow us to survive
○ Taste aversions are learned:
■ Rapidly + in few trials
■ Over long conditioning periods
■ Because of perceptual qualities (eg smell/taste); not act of ingestion itself
■ More often w/ novel foods
A MODERN APPLICATION
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Research w/ cancer PTs who experience nausea
○ Biological preparedness: Propensity for learning particular kinds of assoc’ns over others
THE REAL WORLD: UNDERSTANDING DRUG OVERDOSES
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When drug is injected, environment acts as CS (becomes CR over time)
When in a new environment, brain no longer counteracts
OPERANT CONDITIONING: REINFORCEMENTS FROM
THE ENVIRONMENT
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Operant conditioning: Type of learning in which the consequences of an organism’s behav determine
whether the behav will be repeated in the future
THE DEVELOPMENT OF OPERANT CONDITIONING
EDWARD THORNDIKE (1874-1949): THE LAW OF EFFECT
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Focused on instrumental behavs
Created puzzle box to show law of effect
○ Law of effect: Principle that behavs that are followed by a “satisfying state of affairs” tend to be
repeated; those that produce “unpleasant state of affairs” less likely to be repeated
■ Learning gets stamped into the mind
Cats made lots of trial/error behavs but stopped them once they learned the sol’n + got faster at solving
box
B.F. SKINNER (1904-1990): THE ROLE OF REINFORCEMENT AND PUNISHMENT
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Operant behaviour: Behav that an organism produces that has some impact on the environment
○ Demonstrated using operant chamber/Skinner box
Reinforcer: Any stimulus/event that functions to increase likelihood of the behav that led to it
○ More effective than punishment in promoting learning
○ Positive + negative reinforcement
Primary reinforcer: Satisfy biological needs
○ Eg food; comfort; shelter; warmth
Secondary reinforcer: Assoc’d w/ primary reinforcers through classical conditioning
○ Eg verbal approval; trophies; money; token economies in prison
Punisher: Any stimulus/event that functions to decrease likelihood of behav that led to it
○ Positive + negative punishment
■ Positive punishment = administer something unpleasant
■ Negative punishment = take away something pleasant
Overjustification effect: Circumstances when external rewards can undermine intrinsic satisfaction of
performing a behaviour
Immediate vs delayed reinforcement + punishment
○ Reinforcers lose effectiveness as time passes
○ Delaying reinforcements renders it almost completely ineffective
INCREASES LIKELIHOOD OF
BEHAVIOUR
DECREASES LIKELIHOOD OF
BEHAVIOUR
STIMULUS PRESENTED
Positive reinforcement
Positive punishment
STIMULUS REMOVED
Negative reinforcement
Negative punishment
BASIC PRINCIPLES OF OPERANT CONDITIONING
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Learning takes place in contexts, not free range of any plausible situation
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Discriminative stimulus: Stimulus that indicates a response will be reinforced
○ Same response in a different context likely produces a different outcome
EXTINCTION
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More complicated in operant conditioning (vs classical)
Depends (in part) on how often reinforcement is received
SCHEDULES OF REINFORCEMENT
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Schedules of reinforcement: Organism responds in pattern w/ which reinforcement appeared
○ Skinner
Interval schedules based on time intervals btw reinforcements
Ratio schedules based on ratio of responses to reinforcements
○ Eg paid based on amount of strawberries you pick
○ Burns people out faster
Commission salespeople are on both schedules
SCHEDULE
DEFINITION
EXAMPLE
Fixed-interval
schedule (FI)
Reinforcements presented at fixed time periods, provided
the appropriate response is made
Paycheque every 2 weeks
Variable-interval
schedule (VI)
Behav is reinforced based on an avg time that has expired
since last reinforcement
Bird watchers don’t know when
bird will show up
Fixed-ratio
schedule (FR)
Reinforcement is delivered after a specific # responses
have been made
Rat gets food after pressing bar
10 times
Variable-ratio
schedule (VR)
Delivery of reinforcement is based on a particular avg #
responses
Slot machines calibrated to pay
out based on avg # pulls
Intermittent
reinforcement
When only some of the responses made are followed by
reinforcement
Produces slightly higher rates of responding
Responses more hesitant to extinction (intermittentreinforcement effect)
SHAPING THROUGH SUCCESSIVE APPROXIMATIONS
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Shaping: Learning that results from reinforcement of successive steps to a final desired behav
○ Eg gradually reward pigeon for turning to the left; want it to ultimately spin 360 deg
Superstitious behaviour: Rare/odd behavs may be repeated if accidentally reinforced => may lead to
mistaken beliefs regarding causal relationships
○ Eg lucky charms/rituals
COGNITIVE ELEMENTS OF OPERANT CONDITIONING
EDWARD TOLMAN (1886-1959)
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Saw operant conditioning as a means-end relationship
Latent learning: Condition in which something is learned, but not manifested as a behav’l change until
sometime in the future
Cognitive map: Mental representation of physical features of the environment
○ Eg having an impression of learning that will benefit you later
“Trust” game examined learning + brain activity (fMRI)
NEURAL ELEMENTS OF OPERANT CONDITIONING
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Pleasure centers of brain located in limbic system (Olds & Milner)
Discovery of structures + pathways in brain that deliver rewards through stimulation:
○ Medial forebrain bundle
○ Hypothalamus
○ Nucleus accumbens
Behavs that involve pleasure: eating, drinking; sexual activity
Neurons involved in “reward center” are dopaminergic (DA)
HOT SCIENCE: DOPAMINE AND REWARD LEARNING IN PARKINSON’S DISEASE
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Dopamine neurons play an important role in generating the reward prediction error (Schultz et al.)
Reward-related learning can be impaired in persons w/ Parkinson’s
○ Other studies found when indivs w/ Parkinson’s performed reward-related learning tasks,
disruption occurred in reward prediction error signal
People w/ Parkinson’s who displayed compulsive gambling + shopping disorders related to impulsive
behavs after diagnosis may be related to consequences of drugs that stimulate dopamine receptors
THE EVOLUTIONARY ELEMENTS OF OPERANT CONDITIONING
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Foraging animals explore their environment (even places not reinforcing)
○ Rat’s behaviour in a T-maze
Each species (incl humans) is biologically predisposed to learn some things more readily than others in
ways consistent w/ their evol’nary history
OBSERVATIONAL LEARNING: LOOK AT ME
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Observational learning: Condition in which learning takes place by watching the actions of others
○ Learning through imitation
ALBERT BANDURA (1925-)
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Studied aggressive observational learning using Bobo doll experiment
○ Children imitated adult behaviours + were sensitive to consequences of their aggressive behav
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Diffusion chain: Process in which indivs initially learn a behav by observing another indiv perform that
behav => serve as a model from which other indivs learn the behav
○ Behavioural contagioncy
OBSERVATIONAL LEARNING IN ANIMALS
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Pigeons have learned how to get reinforced for pecking behaviour
Rhesus monkeys learned to fear snakes through an observational diffusion chain
○ Exemplifies biological predisposition to fear snakes
Chimpanzees learned to use a novel tool through observational learning
○ Children showed greater learning of tool’s function
○ Enculturation hypothesis
NEURAL ELEMENTS OF OBSERVATIONAL LEARNING
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Mirror neurons fire to produce observational learning in humans + other species
○ Frontal + parietal lobes
If appropriate neurons fire when another organism is seen performing an action, could indicate awareness
of intentionality OR that animal is anticipating a likely course of future actions
○ Beneficial
Same brain areas activated when one engages in a task or observes another engage in the task (fMRI)
Observational learning of motor skills depends on motor cortex
○ TMS studies
IMPLICIT LEARNING: UNDER THE RADAR
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Implicit learning: Learning that takes place largely w/o awareness of process or products of info
acquisition
○ Some forms of learning begin explicitly but become implicit over time
Habituation: General process where repeated/prolonged exposure to a stimulus results in a gradual
reduction in responding
○ Occurs in simplest organisms (Aplysia sea slug) or humans, but w/o mechanisms for explicit learning
○ Changes may not last long
COGNITIVE APPROACHES TO IMPLICIT LEARNING
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Implicit learning studies
○ Participants memorized artificial grammar letter strings
○ Participants learned grouping rules but were unaware of it
Serial reaction time tasks
○ Participants got faster in rxn time but unaware that there was a pattern
DISTINCT NEURAL PATHWAYS FOR IMPLICIT AND EXPLICIT LEARNING
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Amnesiacs show intact implicit learning but impaired explicit learning (=> different pathways)
○ Damage to hippocampus + medial temporal lobe impairs explicit memory
When shown implicit patterns in a visual dot display, those given explicit instructions to seek patterns
showed different areas of brain activation (vs implicit instructions)
○ Implicit group showed occipital lobe activation => suggests visual processing)
Other studies of artificial grammar learning + sequence learning via serial rxn time tasks show Broca’s
area + motor cortex, respectively, to be involved
LEARNING IN THE CLASSROOM
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Team of psychologists who specialize in learning found 10 learning techniques used by students
1. Distributed practice: Spreading out study activities w/ more time btw repetition of the to-be-learned info
○ On avg, participants retained 47% of studied info (vs 37% after massed practice)
○ More difficult to retrieve info that was studied less recently; more difficult retrieval benefits
subsequent learning more than easy retrieval
○ Cramming: Neglecting to study for an extended period of time + studying intensively just before
an exam
i.
25-50% of college students rely on cramming
○ Massed practice: Studying info w/ little/no time btw repetition
i.
Ebbinghaus’ classic retention of nonsense syllable
2. Interleaved practice: Practice schedule that mixes different kinds of problems/materials within a single
study session
○ Requires students to choose a strategy according to nature of indiv problems
3. Practice testing
○ Proven useful across wide range of materials
○ Most beneficial when test is difficult + considerable retrieval efforts required
○ Consistent w/ desirable difficulties hypothesis
○ Effective w/ verbatim learning + transfer learning
○ Brief tests during lecture can improve learning + reduce tendency of mind to wander
i.
Part of testing value attributed to encouragement to attend lectures in a way that
discourages task-irrelevant activities
4. Control of learning
○ Judgements of learning: Assessments made about how well info is learned + used to control
future study
○ More time used to study items judged to be difficult to learn
○ Overconfidence + feeling of familiarity can be misleading + detract from effective studying
5. Overcoming misleading subjective impressions
○ Use self-testing periodically under exam-like conditions
○ Compare personal learning definitions to actual definitions
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Researchers conclude that becoming an effective learner requires understanding of:
○ Key features of learning + memory
○ Effective learning techniques
○ How to monitor + control one’s own learning
○ Biases that can undermine judgements of learning
OTHER VOICES: LEARNING AT JIFFY LUBE UNIVERSITY
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JLU = education program where the business has incorporated learning techniques to aid employee
training
Employees take online classes online + undergo rigorous testing + recertification every 2 years
○ On-the-job training; coaching from supervisors; learning on simulated “dashboards”
TAKEAWAYS
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Definition of learning
Conditioning (learning assoc’ns)
○ Classical
○ Operant
Respondent behaviour (rabbit example)
Banduras + observational learning
Pavlov
Huxley’s book (Brave New World)
Extinction; spontaneous recovery; generalization
Thorndike + law of effect
Shaping (successive approximation)
Schedules
CHAPTER 6
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EWT = recall memory
Ebbinghaus (nonsense syllables)
Sensory, STM, LTM
○ Working memory (form of short term)
○ STM holds 7 items
○ Peterson/Peterson technique
Rehearsal gets STM into LTM
Explicit vs implicit memory
○ Cerebellum => implicit
Chunking
Mnemonics (ROY G BIV)
Lashley (memory is not localized)
Sleep improves memory
Amnesias
Affect of stress on recall (re: amygdala); flashbulb memories
Context learning
Propranolol
Serial position curve (first + last 5 min of an interview most memorable)
○ Primacy + recency effect
Laurier