Module 1
Discovering Psychology
INTRODUCTION
• Growing up in a strange world
– Autism
• especially abnormal or impaired development in
social interactions, such as hiding to avoid people,
not making eye contact, and not wanting to be
touched
– Autism is marked by difficulties in communicating,
such as grave problems in developing spoken
language or in initiating conversations
DEFINITION OF PSYCHOLOGY
• What do psychologists study?
– Psychology
• the systematic, scientific study of behaviors and
mental processes
– Behaviors
• refers to observable actions or responses in both
humans and animals
– Mental processes
• not directly observable, refer to a wide range of
complex mental processes, such as thinking,
imagining, studying, and dreaming
GOALS OF PSYCHOLOGY
–
–
–
–
Describe
Explain
Predict
Control
GOALS OF PSYCHOLOGY (CONT.)
• Describe
– first goal of psychology is to describe the different
ways that organisms behave
• Explain
– second goal of psychology is to explain the cause of
behavior
GOALS OF PSYCHOLOGY (CONT.)
• Predict
– third goal of psychology is to predict how organisms
will behave in certain situations
• Control
– the fourth goal of psychology is to control an
organism’s behavior
ANSWERING QUESTIONS
• How do psychologists answer questions?
– Approaches to understanding behavior include:
• Biological
• Cognitive
• Behavioral
• Psychoanalytic
• Humanistic
• Cross cultural
ANSWERING QUESTIONS (CONT.)
• Biological approach
– focuses on how our genes, hormones, and nervous
system interact with our environments to influence
learning, personality, memory, motivation, emotions,
and coping techniques
– Examples:
• Autism
• Autism runs in families; supported by the findings
in identical twins
• If one twin has autism, there is a high 90% chance
the other twin will exhibit signs for autistic behavior
ANSWERING QUESTIONS (CONT.)
• Cognitive approach
– examines how we process, store, and use information
and how this information influences what we attend
to, perceive, learn, remember, believe, and feel
– Cognitive neuroscience:
• Involves taking pictures and identifying the
structures and functions of the living brain during
the performance of a wide variety of mental or
cognitive processes, such as thinking, planning,
naming, and recognizing objects
ANSWERING QUESTIONS (CONT.)
• Behavioral approach
– studies how organisms learn new behaviors or modify
existing ones, depending on whether events in their
environments reward or punish these behaviors
– some behaviorists, such as Albert Bandura, disagree
with strict behaviorism
– formulated a theory that includes mental or cognitive
processes in addition to observable behaviors
– Social Cognitive Approach:
• behaviors are influenced not only by environmental
events and reinforcers but also by observation,
imitation, and thought processes
ANSWERING QUESTIONS (CONT.)
• Psychoanalytic approach
– Based on the belief that childhood experiences
greatly influence the development of later personality
traits and psychological problems
– stresses the influence of unconscious fears, desires,
and motivations on thoughts, behaviors, and the
development of personality traits and psychological
problems later in life
ANSWERING QUESTIONS (CONT.)
• Humanistic approach
– emphasizes that each individual has great freedom in
directing his or her future, a large capacity for
personal growth, a considerable amount of intrinsic
worth, and enormous potential for self-fulfillment
ANSWERING QUESTIONS (CONT.)
• Cross-cultural approach
– examines the influence of cultural and ethnic
similarities and differences on psychological and
social functioning of a culture’s members
– Differences in how countries diagnose autism:
– United States:
• symptoms described 60 years ago
• first thought to be caused by environmental
factors, (cold parents)
• 1960’s changed to searching for biological
problems
• Diagnoses begins at 2-3 years of age
HISTORICAL APPROACHES
• How did psychology begin?
– Structuralism: Elements of the Mind
– Functionalism: Functions of the Mind
– Gestalt Approach: Sensations versus Perceptions
– Behaviorism: Observable Behaviors
Module 2
• Psychology & Science
ANSWERING QUESTIONS
• Research methods
– Survey
– Case study
– Experiment
ANSWERING QUESTIONS (CONT.)
• Researchers use all three methods
– survey
– case study
– experiment
• each method provides a different kind of information
SURVEYS
• Survey
– way to obtain information by asking many individuals
– answer a fixed set of questions about particular
subjects
SURVEYS (CONT.)
• Disadvantages
– information can contain errors
– results can be biased
• Advantage
– efficient way to obtain much information from a large
number of people
CASE STUDY
• Case study
– an in-depth analysis of the thoughts, feelings, beliefs,
experiences, behaviors, or problems of a single
individual
– Personal Case Study: Testimonial
• statement in support of a particular viewpoint
based on detailed observation of a person’s own
personal experience
– Error and Bias: Self-fulfilling Prophecy
• A strong belief or making a statement (prophecy)
about a future behavior and then acting, usually
unknowingly, to fulfill or carry out the behavior
CASE STUDY (CONT.)
• Disadvantage
– detailed information about a particular person may not
apply to others
• Advantage
– detailed information allows greater understanding of a
particular person’s life
EXPERIMENT
• Experiment
– a method for identifying cause-and-effect
relationships by following a set of rules and guidelines
that minimize the possibility of error, bias, and chance
occurrences
EXPERIMENT (CONT.)
• Disadvantage
– information obtained in one experimental situation or
laboratory setting may not apply to other situations
• Advantage
– has the greatest potential for identifying cause-andeffect relationships with less error and bias than either
surveys or case studies
CULTURAL DIVERSITY: USE OF PLACEBOS
• Placebo
– intervention, such as taking a pill, receiving
and injection, or undergoing an operation, that
resembles medical therapy but which in fact,
has no medical effects
• Placebo effect
– change in the patient’s illness that is
attributable to an imagined treatment rather
than to a medical treatment
CULTURAL DIVERSITY: USE OF PLACEBOS
(CONT.)
– researchers believe that placebos work by reducing
tension and distress and by creating powerful selffulfilling prophecies
– individuals think and behave as if the drug, actually a
placebo, is effective
CULTURAL DIVERSITY: USE OF PLACEBOS
(CONT.)
• Placebo examples
– Rhino Horn
– Bear Gallbladders
– Tiger Bones
– Cough Medication
CORRELATION
• Correlation
– an association or relationship between the occurrence
of two or more events
• Correlation coefficient
– a number that indicates the strength of a relationship
between two or more events: the closer the number is
to –1.00 or +1.00, the greater is the strength of the
relationship
CORRELATION
CORRELATION (CONT.)
• Perfect positive correlation coefficient
– +1.00 means that an increase in one event is always
matched by an equal increase in a second event
• Positive correlation coefficient
– indicates that as one event tends to increase, the
second event tends to, but does not always, increase
– increases from +0.01 to +0.99 indicate a
strengthening of the relationship between the
occurrence of two events
CORRELATION (CONT.)
• Zero correlation
– indicates that there is no relationship between the
occurrence of one event and the occurrence of a
second event
• Negative correlation coefficient
– indicates that as one event tends to increase, the
second event tends to, but does not always, decrease
– -0.01 to -0.99 indicates a strengthening in the
relationship of one event increasing and the other
decreasing
CORRELATION (CONT.)
• Perfect negative correlation coefficient
– -1.00 means that an increase in one event is always
matched by an equal decrease in a second event
– correlations such as –1.00 are virtually never found in
applied psychological research
DECISIONS ABOUT DOING RESEARCH
• What is the best technique for answering a question?
– Questionnaires and interviews
– Laboratory experiments
– Standardized tests
– Animal models
DECISIONS ABOUT DOING RESEARCH
(CONT.)
• Interview
– technique for obtaining information by asking
questions, ranging from open-ended to highly
structured, about a subject’s behaviors and attitudes,
usually in a one-on-one situation
• Questionnaire
– technique for obtaining information by asking subjects
to read a list of written questions and check off
specific answers
DECISIONS ABOUT DOING RESEARCH
(CONT.)
• Laboratory experiments
– techniques to gather information about the brain,
genes, or behavior with the least error and bias by
using a controlled environment that allows careful
observation and measurement
• Standardized tests
– technique to obtain information by administering a
psychological test that has been given to hundreds of
people and shown to reliably measure thought
patterns, personality traits, emotions, or behaviors
DECISIONS ABOUT DOING RESEARCH
(CONT.)
• Animal Models
– involves examining or manipulating some behavioral,
genetic, or physiological factor that closely
approximates some human problem, disease, or
condition
– Example:
• human stem cell transplants in mice with spinal
cord injuries
DECISIONS ABOUT DOING RESEARCH
(CONT.)
• Choosing research settings
– Naturalistic setting
– Laboratory setting
DECISIONS ABOUT DOING RESEARCH
(CONT.)
• Naturalistic setting
– relatively normal environment in which researchers
gather information by observing individuals’ behaviors
without attempting to change or control the situation
• Laboratory setting
– involves studying individuals under systematic and
controlled conditions, with many of the real-world
influences eliminated
SCIENTIFIC METHOD: EXPERIMENT
• Advantages of scientific method
– Scientific Method
• approach of gathering information and answering
questions so that errors and biases are minimized
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Conducting an Experiment: seven rules
– Rule 1: Ask
– Rule 2: Identify
– Rule 3: Choose
– Rule 4: Assign
– Rule 5: Manipulate
– Rule 6: Measure
– Rule 7: Analyze
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Rule 1: Ask
– hypothesis
– educated guess about some phenomenon stated in
precise, concrete language to rule out any confusion
or error in the meaning of its terms
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Rule 2: Identify
– independent variable
• a treatment or something that the researcher
controls or manipulates
– dependent variable
• one or more of the subjects’ behaviors that are
used to measure the potential effects of the
treatment or independent variable
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Rule 3: Choose
– random selection
• each participant in a sample population has an
equal chance of being selected for the experiment
• Rule 4: Assign
– experimental group
• those who receive the treatment
• control group
• participants who undergo all the same procedures
as the experimental participants except that the
control participants do not receive the treatment
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Rule 5: Manipulate
– double blind procedure
• neither participants nor researchers know which
group is receiving which treatment
• Rule 6: Measure
– by manipulating the treatment so that the
experimental group receives a different treatment
than the control group, researchers are able to
measure how the independent variable (treatment)
affects those behaviors that have been selected as
the dependent variables
SCIENTIFIC METHOD: EXPERIMENT (CONT.)
• Rule 7: Analyze
– statistical procedures
• used to determine whether differences observed in
dependent variables (behaviors) are due to
independent variables (treatment) or to error or
chance occurrence
Module 3
Brain’s Building Blocks
DEVELOPMENT OF THE
BRAIN
• fact that your brain does not develop into a
nose is because of instructions contained
in your genes
• Genes
– chains of chemicals that are arranged like
rungs on a twisting ladder
– there are about 20,000-25,000 genes that
contain chemical instructions that equal about
300,000 pages of written instructions
– genes program the development of individual
parts into a complex body & brain
DEVELOPMENT OF THE
BRAIN (CONT.)
DEVELOPMENT OF THE
BRAIN (CONT.)
• Insert pictures of
– Six week old brain
– Mature brain
STRUCTURE OF THE BRAIN
• Human brain:
– is shaped like a small wrinkled melon
– 1,350 grams (less than 3 pounds)
– pinkish-white color
– consistency of firm Jell-O
– Fueled by sugar (glucose)
– 1 trillion cells divided into
• glial cells
• neurons
STRUCTURE OF THE BRAIN
(CONT.)
• Glial cells
• 3 Functions:
– guide the growth of developing neurons
– wrap around neurons and form an insulation
to prevent interference from other electrical
signals
– release chemicals that influence a neuron’s
growth and function
STRUCTURE OF THE BRAIN
(CONT.)
STRUCTURE OF THE BRAIN
(CONT.)
• Neuron
– a brain cell with 2 specialized extensions
– one extension is for receiving electrical
signals
– the other extension is for transmitting
electrical signals
STRUCTURE OF THE BRAIN
(CONT.)
STRUCTURE OF THE BRAIN
(CONT.)
• Insert: video Main Parts of the Neuron,
Psychology Digital Video Library 3.0.
Debra Schwiesow, page 17
GROWTH OF NEW NEURONS
• Can a brain grow new neurons?
– canary brain
• can grow about 20,000 neurons a day during the
spring (learns new breeding song)
– primate and human brain
• researchers conclude that adult monkey and
human brains are capable of growing relatively
limited numbers of neurons throughout adulthood
• Some new neurons play important role in
continuing to learn and remember new things
(hippocampus)
GROWTH OF NEW NEURONS
(CONT.)
• Repairing the Brain
– advances in stem research suggest the
human brain may be able to grow more
neurons
– repair damages:
• accident
• disease
• Alzheimer’s
PARTS OF THE NEURON
• Cell Body
– large egg-shaped structure that provides fuel,
manufactures chemicals, and maintains the
entire neuron in working order
• Dendrite
– branchlike extensions that arise from the cell
body
– receive signals from other neurons, muscles,
or sense organs
PARTS OF THE NEURON
(CONT.)
• Axon
– a single threadlike structure that extends from
and carries signals away from the cell body to
neighboring neurons, organs, or muscles
• Myelin Sheath
– looks like separate tubelike segments
composed of fatty material that wraps around
and insulates an axon
– prevents interference from electrical signals
generated in adjacent axons
PARTS OF THE NEURON
(CONT.)
• End bulbs or Terminal bulbs
– located at extreme ends of the axon’s
branches
– miniature container that stores chemicals
called neurotransmitters (used to
communicate with neighboring cells)
• Synapse
– infinitely small space (20-30 billionths of a
meter)
– exists between and end bulb and its adjacent
body organ, heart, muscles, or cell body
ALZHEIMER’S DISEASE AND
NEURONS
• Alzheimer’s disease
– excessive buildup of gluelike substances
– gradually destroy neurons
• Researchers recently discovered an
experimental vaccine that may help stop
the buildup of these gluelike, killer
substances and they continue to search
for other interventions
PERIPHERAL & CENTRAL
NERVOUS SYSTEM
• Peripheral Nervous System
– made up of nerves that are located
throughout the body, except in the brain &
spinal cord
• Central Nervous System
– made up of neurons located in the brain &
spinal cord
PERIPHERAL & CENTRAL
NERVOUS SYSTEM (CONT.)
• Nerves
– stringlike bundles of axons and dendrites that
come from the spinal cord and are held
together by connective tissue
– carry information from the senses, skin,
muscles, and the body’s organs to and from
the spinal cord
– nerves in the peripheral nervous system have
the ability to grow or reattach if severed or
damaged
SENDING INFORMATION:
ACTION POTENTIAL
SEQUENCE
– axon membrane has chemical gates that can
open to allow electrically charged particles to
enter or can close to keep out these particles
– ions are chemical particles that have electrical
charges
– opposite charges attract and like charges
repel
SENDING INFORMATION:
ACTION POTENTIAL
SEQUENCE (CONT.)
•
SENDING INFORMATION:
ACTION POTENTIAL
SEQUENCE
(CONT.)
Resting state
– the axon has a charge
– the charge results from the axon membrane
separating positive ions on the outside from
negative ions on the inside
SENDING INFORMATION:
ACTION POTENTIAL
SEQUENCE (CONT.)
• Action potential
– tiny electric current that is generated when the
positive sodium ions rush inside the axon
– enormous increase of sodium ions inside the
axon causes the inside of the axon to reverse
its charge
– inside becomes positive and outside becomes
negative
SENDING INFORMATION:
ACTION POTENTIAL
SEQUENCE (CONT.)
The Action Potential
PLAY
VIDEO
SENDING INFORMATION:
NERVE IMPULSE
• Sending information
– action potential is a tiny electrical current that
is generated when the positive sodium ions
rush inside the axon
– the enormous increase of Na ions inside the
axon causes the inside to reverse its charge
– the inside becomes positive & the outside
becomes negative
SENDING INFORMATION:
NERVE IMPULSE (CONT.)
• All-or-None law
– if an action potential starts at the beginning of
the axon, the action potential will continue at
the same speed segment to segment to the
very end of the axon
• Nerve impulse
– nerve impulse is made up of 6 action
potentials, with the first occurring at the
beginning of the axon
SENDING INFORMATION:
NERVE IMPULSE (CONT.)
TRANSMITTERS
• A transmitter is a chemical messenger that
transmits information between nerves and
body organs, such as muscles and heart
• Excitatory and Inhibitory
– excitatory transmitters
• open chemical locks and turn on neurons
– inhibitory transmitters
• block chemical locks and turn off neurons
NEUROTRANSMITTER
• Neurotransmitters
– dozens of different chemicals that are made
by neurons and then used for communication
between neurons during the performance of
mental or physical activities
ALCOHOL
• Alcohol (ethyl alcohol)
– A psychoactive drug that is classified as a
depressant, which means that it depresses
the activity of the central nervous system
ALCOHOL
REFLEX
• Reflex
– unlearned, involuntary reaction to some
stimulus
– neural connections underlying a reflex are
prewired by genetic instructions
REFLEX (CONT.)
• Reflex sequence
– sensors
• sensors trigger neurons that start the withdrawal
effect
– afferent neurons
• carry information from the senses to the spinal
cord
REFLEX (CONT.)
– Interneuron
• relatively short neuron whose primary task
is making connections between other
neurons
– Efferent neuron
• carry information away from the spinal cord
to produce responses in various muscles
and organs throughout the body
Module 4
Incredible Nervous System
GENES & EVOLUTION (CONT.)
• Fertilization
– human life has its beginnings when a father’s sperm,
which contains 23 chromosomes, penetrates a
mother’s egg, which contains 23 chromosomes
GENES & EVOLUTION (CONT.)
GENES & EVOLUTION (CONT.)
• Zygote
– the largest human cell, about the size of a grain of
sand
– a zygote is a cell that results when an egg is fertilized
– a zygote contains 46 chromosomes arranged in 23
pairs
GENES & EVOLUTION (CONT.)
• Genes and proteins
– Gene
• a specific segment on the long strand of DNA that
contains instructions for making proteins
– Proteins
• chemical building blocks from which all the parts of
the brain and body are constructed
GENES & EVOLUTION (CONT.)
• Genome
– The Human Genome Project
– began in 1995 and cost over $2.7 billion
– reached its first goal in 2003 of mapping all the
human genes
– researchers found only about 30,000 human genes
instead of the estimated 100,000
EVOLUTION OF THE HUMAN BRAIN
• Evolution of the human brain
– 1859 Charles Darwin published the Origin of Species
• Theory of Evolution
– says that different species arose from a common
ancestor and that those species that survived were
best adapted to meet the demands of their
environment
– humans and chimpanzees share at least 98% of their
DNA
STUDYING THE LIVING BRAIN (CONT.)
• MRI
– magnetic resonance imagery
– involves passing nonharmful radio frequencies
through the brain
• fMRI
– functional magnetic resonance imaging
– measures the activity of specific neurons that are
functioning during cognitive tasks, such as thinking,
listening
STUDYING THE LIVING BRAIN (CONT.)
• Brain scans and Cognitive Neuroscience
– PET scan
– positron emission tomography
– involves injecting a slightly radioactive solution into
the blood and then measuring the amount of radiation
absorbed by brain cells called neurons
STUDYING THE LIVING BRAIN (CONT.)
• Brain scans and Cognitive Neuroscience
– Neuroimaging
• PET and fMRI scans are used to identify and map
the living brain’s neural activity as a person
performs complex behavioral and cognitive tasks,
such as:
– seeing
– moving
– thinking
– speaking
– empathizing
– trusting
– even reacting to TV violence
ORGANIZATION OF THE BRAIN (CONT.)
• Central nervous system - CNS
– made up of the brain and spinal cord
ORGANIZATION OF THE BRAIN (CONT.)
• Peripheral nervous system - PNS
– includes all the nerves that extend from the spinal
cord and carry messages to and from various
muscles, glands, and sense organs located
throughout the body
• Subdivisions of the PNS
– somatic nervous system
– autonomic nervous system - ANS
– sympathetic division
– parasympathetic division
ORGANIZATION OF THE BRAIN (CONT.)
• Somatic nervous system
– network of nerves that connect either to sensory
receptors or to muscles that you can move voluntarily,
such as muscles in your limbs, back, neck, and chest
– nerves contain two kinds of fibers
• Afferent
– sensory fibers; carry information to the brain
• Efferent
– motor fibers; carry information from brain or
spinal cord to the muscles
ORGANIZATION OF THE BRAIN (CONT.)
• Autonomic nervous system - ANS
– regulates heart rate, breathing, blood pressure,
digestion, hormone secretion, and other functions
• Sympathetic division
– triggered by threatening or challenging physical or
psychological stimuli, increases physiological arousal
and prepares the body for action
• Parasympathetic division
– returns the body to a calmer, relaxed state and is
involved in digestion
ORGANIZATION OF THE BRAIN (CONT.)
• Major Parts of the Brain
– Forebrain
– Midbrain
– Hindbrain
• pons
• medulla
• cerebellum
ORGANIZATION OF THE BRAIN (CONT.)
• Forebrain
– largest part of the brain
– has right and left sides called hemispheres
– hemispheres are responsible for a number of
functions, including learning and memory, speaking
and language, emotional responses, experiencing
sensations, initiating voluntary movements, planning,
and making decisions
ORGANIZATION OF THE BRAIN (CONT.)
• Midbrain
– has a reward or pleasure center, which stimulated by
food, sex, money, music, looking at attractive faces,
and some drugs (cocaine)
– has areas for visual and auditory reflexes
– contains the reticular formation, which arouses the
forebrain so that it is ready to process information
from the senses
ORGANIZATION OF THE BRAIN (CONT.)
• Hindbrain
– Has three distinct structures:
• Pons
• Medulla
• Cerebellum
ORGANIZATION OF THE BRAIN (CONT.)
• Pons
– functions as a bridge to interconnect messages
between the spinal cord and brain
• Medulla
– located on top of the spinal cord
– includes a group of cells that control vital reflexes,
such as respiration, heart rate, and blood pressure
• Cerebellum
– located in the very back and underneath the brain
– involved in coordinating motor movements but not in
initiating voluntary movements
CONTROL CENTERS: FOUR LOBES (CONT.)
• Frontal lobe
– involved with personality, emotions, and motor
behaviors
• Parietal lobe
– involved with perception and sensory experiences
• Occipital lobe
– involved with visual processing
• Temporal lobe
– involved with hearing and speaking
CONTROL CENTERS: FOUR LOBES (CONT.)
• Temporal lobe: functions
– primary auditory cortex
– located on top edge of each temporal lobe, receives
electrical signals from receptors in the ears and
transforms these signals into meaningful sound
sensations, such as vowels and consonants
CONTROL CENTERS: FOUR LOBES (CONT.)
• Temporal lobe: functions
– auditory association area
– located directly below the primary auditory cortex
– transforms basic sensory information, such as noises
or sounds, into recognizable auditory information,
such as words or music
CONTROL CENTERS: FOUR LOBES (CONT.)
• Occipital lobe: functions
– vision
– primary visual cortex
– located at the very back of the occipital lobe
– receives electrical signals from receptors in the eyes
and transforms these signals into meaningless basic
visual sensations, such as lights, lines, shadows,
colors, and textures
CONTROL CENTERS: FOUR LOBES (CONT.)
• Occipital lobe: functions
– visual association area
– transforms basic sensations, such as lights, lines,
colors, and textures, into complete, meaningful visual
perceptions, such as persons, objects, or animals
CONTROL CENTERS: FOUR LOBES (CONT.)
• Visual agnosia
– individual fails to recognize some object, person, or
color
– has ability to see and even describe pieces or parts of
some visual stimulus
CONTROL CENTERS: FOUR LOBES (CONT.)
• Neglect Syndrome
– refers to the failure of a patient to see objects or parts
of the body on the side opposite the brain damage
– may dress only on one side of body
– may deny that opposite body parts are theirs
LIMBIC SYSTEM: OLD BRAIN
• group of about half a dozen interconnected structures
that make up the core of the forebrain
• involved with regulating many motivational behaviors
such as obtaining food, drink, and sex
• organizing emotional behaviors such as fear, anger, and
aggression; storing memories
• Structures and functions
– Hypothalamus
– Amygdala
– Thalamus
– Hippocampus
LIMBIC SYSTEM: OLD BRAIN
• Structures and functions
– Hypothalamus
– Amygdala
– Thalamus
– Hippocampus
LIMBIC SYSTEM: OLD BRAIN (CONT.)
• Autonomic nervous system
– Sympathetic
– Parasympathetic
LIMBIC SYSTEM: OLD BRAIN (CONT.)
• Autonomic nervous system
– Sympathetic
• triggered by threatening or challenging physical or
psychological stimuli
– Physiological responses
• increased heart rate, increased blood pressure,
and dilated pupils
• fight or flight
LIMBIC SYSTEM: OLD BRAIN (CONT.)
• Autonomic nervous system
– Parasympathetic
• decreases physiological arousal
• returns the body to a calmer, more relaxed state
• stimulates digestion during eating
– Physiological responses
• decreases heart rate
• lowers blood pressure
• stimulate digestion
• body returns to more relaxed state
LIMBIC SYSTEM: OLD BRAIN (CONT.)
• Autonomic nervous system
– Homeostasis
• sympathetic and parasympathetic systems work
together to keep the body’s level of arousal in
balance for optimum functioning
Module 5
Sensation
THREE DEFINITONS
• Adaptation:
– the decreasing response of the sense organs,
the more they are exposed to a continuous
level of stimulation
• Sensation versus perception:
– relatively meaningless bits of information that
result when the brain processes electrical
signals that come from the sense organs
– perceptions:
– meaningful sensory experiences that result
after the brain combines hundreds of
THREE DEFINITONS (CONT.)
• eyes, ears, nose, skin, and tongue are
complex, miniaturized, living sense organs
that automatically gather information about
your environment
• Transduction:
– process in which a sense organ changes, or
transforms, physical energy into electrical
signals that become neural impulses, which
may be sent to the brain for processing
EYE: VISION
• Structure and function
– eyes perform two separate processes
– first: gather and focus light into precise area in
the back of eye
– second: area absorbs and transforms light
waves into electrical impulses
– process called transduction
EYE: VISION (CONT.)
• Structure and function
– Vision: 7 steps
•
•
•
•
•
•
•
Image reversed
Light waves
Cornea
Pupil
Iris
Lens
Retina
EYE: VISION (CONT.)
• rods:
– photoreceptor that contain a single chemical,
called rhodopsin
– activated by small amounts of light
– very light sensitive
– allow us to see in dim light
– see only black, white and shades of gray
EYE: VISION (CONT.)
• cones:
– photoreceptors that contain three chemicals
called opsins
– activated in bright light
– allow us to see color
– cones are wired individually to neighboring
cells
– allows us to see fine detail
EYE: VISION (CONT.)
• Visual pathways: eye to brain
– Primary visual cortex
• the back of the occipital lobes is where primary
visual cortex transforms nerve impulses into simple
visual sensations
– Visual association areas
• the primary visual cortex sends simple visual
sensations to neighboring association areas
EYE: VISION (CONT.)
• Color Blindness
– inability to distinguished two or more shades
in the color spectrum
– Monochromatic:
• total color blindness
• black and white
• result of only rods and one kind of functioning cone
– Dichromatic:
•
•
•
•
trouble distinguishing red from green
two kinds of cones
inherited genetic defect
mostly in males
EAR: AUDITION
• Stimulus:
– Sound waves
• stimuli for hearing (audition)
• ripples of different sizes
• sound waves travel through space with varying
heights and frequency
– Height
• distance from the bottom to the top of a sound
wave
• called amplitude
– Frequency
• number of sound waves occurring within one
EAR: AUDITION (CONT.)
• Loudness
– subjective experience of a sound’s intensity
– brain calculates loudness from specific
physical energy (amplitude of sound waves)
• Pitch
– subjective experience of a sound being high
or low
– brain calculates from specific physical stimuli
– speed or frequency of sound waves
– measured in cycles (how many sound waves
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Outer ear
•
•
•
•
consists of three structures
external ear
auditory canal
tympanic membrane
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Outer ear
• external ear
– oval shaped structure that protrudes from the side of the
head
• function
– pick up sound waves and then send them down the
auditory canal
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Outer ear
• auditory canal
– long tube that funnels sound waves down its length so
that the waves strike the tympanic membrane (ear drum)
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Outer ear
• tympanic membrane
– taut, thin structure commonly called the eardrum
– Sound waves strike the tympanic membrane and cause it
to vibrate
EAR: AUDITION (CONT.)
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Middle ear
• bony cavity sealed at each end by membranes.
• the membranes are connected by three tiny bones
called ossicles
• hammer, anvil and stirrup
– hammer is attached to the back of the tympanic
membrane
– anvil receives vibrations from the hammer
– stirrup makes the connection to the oval window (end
membrane)
EAR: AUDITION (CONT.)
• Outer, middle, and inner ear
– Inner ear
• contains two structures sealed by bone
– cochlea: involved in hearing
– vestibular system: involved in balance
EAR: AUDITION (CONT.)
• Cochlea
– bony coiled exterior that resembles a snail’s
shell
– contains receptors for hearing
– function is transduction
– transforms vibrations into nerve impulses that
are sent to the brain for processing into
auditory information
EAR: AUDITION (CONT.)
• Auditory brain areas
– sensations and perceptions
– two step process occurs after the nerve
impulses reach the brain
– primary auditory cortex
– top edge of temporal lobe
– transforms nerve impulses into basic auditory
sensations
– auditory association area
– combines meaningless auditory sensations
into perceptions, which are meaningful
melodies, songs, words, or sentences
VESTIBULAR SYSTEM:
BALANCE
• Position and balance
– vestibular system is located above the
cochlea in the inner ear
– includes semicircular canals
– bony arches set at different angles
– each semicircular canal is filled with fluid that
moves in response to movements of your
head
– canals have hair cells that respond to the fluid
movement
– function of vestibular system
– include sensing the position of the head,
CHEMICAL SENSES
• Taste
– chemical sense because the stimuli are
various chemicals
– tongue
– surface of the tongue
– taste buds
CHEMICAL SENSES (CONT.)
• Tongue
– Five basic tastes
•
•
•
•
•
sweet
salty
sour
bitter
umami: meaty-cheesy taste
CHEMICAL SENSES (CONT.)
• Surface of the tongue
– chemicals, which are the stimuli for taste,
break down into molecules
– molecules mix with saliva and run into narrow
trenches on the surface of the tongue
– molecules then stimulate the taste buds
CHEMICAL SENSES (CONT.)
• Taste buds
– shaped like miniature onions
– receptors for taste
– chemicals dissolved in saliva activate taste
buds
– produce nerve impulses that reach areas of
the brain’s parietal lobe
– brain transforms impulses into sensations of
taste
• Flavor
– combination of taste and smell
CHEMICAL SENSES (CONT.)
CHEMICAL SENSES (CONT.)
• Smell, or olfaction
– Steps for olfaction
•
•
•
•
Stimulus
Olfactory cells
Sensation and memories
Functions of olfaction
CHEMICAL SENSES (CONT.)
• Smell, or olfaction
– Olfactory cells
• receptors for smell are located in a I-inch-square
patch of tissue in the uppermost part of the nasal
passages.
• olfactory cells are covered in mucus
• which dissolve volatile molecules and stimulate the
cells
• the cells trigger nerve impulses that travel to the
brain
• which interprets the impulses as different smells
CHEMICAL SENSES (CONT.)
• Smell, or olfaction
– Sensations and memories
• nerve impulses travel to the olfactory bulb
• impulses are relayed to the primary olfactory
cortex
• cortex transforms nerve impulses into olfactory
sensations
• can identify as many as 10,000 different odors
• we stop smelling our deodorants or perfumes
because of decreased responding
• called adaptation
TOUCH
• Touch
– includes pressure, temperature, and pain
TOUCH (CONT.)
TOUCH (CONT.)
• Receptors in the skin
– skin
– hair receptors
– free nerve endings
– Pacinian corpuscle
TOUCH (CONT.)
• Skin
– outermost layer
– thin film of dead cells containing no receptors
– just below, are first receptors which look like
groups of threadlike extensions
– middle and fatty layer
– variety of receptors with different shapes and
functions
– some are hair receptors
TOUCH (CONT.)
• Hair receptors
– free nerve endings wrapped around the base
of each hair follicle
– hair follicles fire with a burst of activity when
first bent
– if hair remains bent for a period of time, the
receptors will cease firing
– sensory adaptation
– example: wearing a watch
TOUCH (CONT.)
• Brain areas
– somatosensory cortex
– located in the parietal lobe
– transforms nerve impulses into sensations of
touch temperature, and pain
Module 6
Perception
PERCEPTUAL THRESHOLDS
• Threshold
– a point above which a stimulus is perceived
and below which it is not perceived
– threshold determines when we first become
aware of a stimulus
PERCEPTUAL THRESHOLDS
(CONT.)
• Becoming aware of a stimulus
– Gustav Fechner
• defined the absolute threshold as the smallest
amount of stimulus energy (such as sound or light)
that can be observed or experienced
– Absolute threshold
• the intensity level of a stimulus such that a person
will have a 50% chance of detecting it
PERCEPTUAL THRESHOLDS
(CONT.)
• Subliminal stimulus
– has an intensity that gives a person less than
a 50% chance of detecting the stimulus
– breast cancer
• accuracy problems
– looking for ways to lower the threshold for detecting
cancerous tumors and thus save patients
– recently, use of digital mammograms (allows for images
to be enhanced or magnified) is better in detecting
cancerous tumors in women
PERCEPTUAL THRESHOLDS
(CONT.)
• E. H. Weber
– worked on the problem of how we judge
whether a stimulus, such as loud music, has
increased or decreased in intensity
– concept of just noticeable difference (JND)
– refers to the smallest increase or decrease in
the intensity of a stimulus that a person is
able to detect
• Weber’s law
– The increase in intensity of a stimulus needed
to produce a just noticeable difference grows
SENSATION VERSUS
PERCEPTION
• Basic Differences
– Sensations
• our first awareness of some outside stimulus
• outside stimulus activates sensory receptors,
which in turn produce electrical signals that are
transformed by the brain into meaningless bits of
information
– Perceptions
• the experience we have after our brain assembles
and combines thousands of individual sensations
into a meaningful pattern or image
SENSATION VERSUS
PERCEPTION (CONT.)
• Changing sensation into perception
– Stimulus
• change of energy in the environment, such as light
waves, sound waves, mechanical pressure, or
chemicals
– Transduction
• change physical energy into electrical signals
• electrical signals are changed into impulses that
travel into the brain
– Brain
• impulses from senses first go to different primary
areas of the brain
SENSATION VERSUS
PERCEPTION (CONT.)
• Changing sensation into perception
– brain: association areas
– sensation impulses are sent to the
appropriate association area in the brain
• Personalized perceptions
– each of us has a unique set of personal
experiences, emotions, and memories that
are automatically added to our perceptions by
other areas of the brain
RULES OF ORGANIZATION
• Structuralist versus Gestalt psychologists
– Structuralists
• believed that you add together hundreds of basic
elements to form complex perceptions
– Gestaltists
• believe our brains follow a set of rules that specify
how individual elements are to be organized into a
meaningful pattern, or perception
RULES OF ORGANIZATION
(CONT.)
• Organizational rules
– rules of organization: identified by Gestalt
psychologists
• specify how our brains combine and organize
individual pieces or elements into a meaningful
perception
– Figure-ground
• states: in organizing stimuli, we tend to
automatically distinguish between a figure and a
ground
– Similarity
• states: in organizing stimuli, we group together
RULES OF ORGANIZATION
(CONT.)
– Closure
• states: in organizing stimuli, we tend to fill in any
missing parts of a figure and see the figure as
complete
– Proximity
• states: in organizing stimuli, we group together
objects that are physically close to one another
– Simplicity
• states: stimuli are organized in the simplest way
possible
– Continuity
• states: in organizing stimuli, we tend to favor the
smooth or continuous paths when interpreting a
PERCEPTUAL CONSTANCY
• Size, shape, brightness & color constancy
– Size constancy
• refers to our tendency to perceive objects as
remaining the same size even when their images
on the retina are continually growing or shrinking
– Shape constancy
• refers to our tendency to perceive an object as
retaining its same shape even though when we
view it from different angles, its shape is
continually changing its image on the retina
PERCEPTUAL CONSTANCY
(CONT.)
• Size, shape, brightness & color constancy
– Brightness constancy
• refers to the tendency to perceive brightness as
remaining the same in changing illumination
– Color constancy
• refers to the tendency to perceive colors as
remaining stable despite differences in lighting
DEPTH PERCEPTION
• Binocular (two eyes) depth cues
– Depth perception
• refers to the ability of your eye and brain to add a
third dimension, depth, to all visual perceptions,
even though images projected on the retina are in
only two dimensions, height, and width
– Binocular depth cues
• depends on the movement of both eyes
– Convergence
• refers to a binocular cue for depth perception
based on signals sent from muscles that turn the
eyes
DEPTH PERCEPTION
DEPTH PERCEPTION (CONT.)
DEPTH PERCEPTION (CONT.)
• Monocular depth cues
– produced by signals from a single eye
– Linear perspective
• monocular depth cue that results as parallel lines
come together, converge, in the distance
– Relative size
• monocular depth cue that results when we expect
two objects to be the same size and they are not
– Interposition
• monocular depth cue that comes into play when
objects overlap
DEPTH PERCEPTION (CONT.)
• Monocular depth cues
– Light and shadow
• monocular depth cues where brightly lit objects
appear closer, while objects in shadows appear
farther away
– Texture gradient
• monocular depth cue in which areas with sharp,
detailed texture are interpreted as being closer and
those with less sharpness and poorer detail are
perceived as more distant
DEPTH PERCEPTION (CONT.)
• Monocular depth cues
– Atmospheric perspective
• monocular depth cue that is created by the
presence of dust, smog, clouds, or water vapor
– Motion parallax
• monocular depth cue based on the speed of
moving objects
ILLUSIONS
• Strange perceptions
– Illusion
• a perceptual experience in which you perceive an
image as being so strangely distorted that, in
reality, it cannot and does not exist
– Impossible figure
• perceptual experience in which a drawing seems
to defy basic geometric laws
ILLUSIONS (CONT.)
SUBLIMINAL PERCEPTION
• Subliminal Message
– brief auditory or visual message that is
presented below the absolute threshold
– means that there is less than a 50% chance
that the message will be perceived
• Self-fulfilling prophecies
– involve having strong beliefs about changing
some behavior and then acting, unknowingly,
to change that behavior