CRITICAL THINKING!
- Types of Psychology!
- Clinical psychology: The study and treatment of mental disorders!
- Cognitive psychology: The study of mental processes e.g the consciousness, attention,
memory decision making and problem solving !
- Behavioural/biopsychology neuroscience: The study of the biological underpinnings of
behaviour - How the brain processes and how genes and hormones influence actions,
thoughts and feelings.!
- Developmental psychology: Human physical, psychological and social development!
- Experimental psychology: Focuses on basic processes such as learning, sensory systems,
perception and motivational states!
- Industrial-organisational psychology: Studies people’s behaviour in the workplace !
- Personality performance: Focuses on the study of human personality - How different traits
relate to one another and influence behaviour!
- Social psychology: Examines people’s thoughts, feelings and behaviour pertaining to the
social world - How people influence one another, behave in groups and form impressions and
attitudes
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- Pitfalls of everyday approaches!
- Mental shortcuts: Judging based on assumptions and stereotypes !
- Conformation bias: Selectively paying attention to information that is consistent with our
beliefs while downplaying or ignoring information that is inconsistent!
- Failure to consider alternative explanations: We assume that one factor has caused
something to happen when actually perhaps a less obvious factor was the major cause many factors in real life operate simultaneously
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- Levels of analysis!
- Biological level: Brain processes and genetic influences!
- Psychological level: Thoughts, feelings and motives!
- Environmental level: Past and current physical and social environments to which we are
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Perspectives on behaviour!
- Structuralism: The analysis of the basic components of the consciousness - How things
work!
- Functionalism: The analysis of the functions/purposes of consciousness rather than its
elements - Why things happen!
- Psychodynamic: Causes of behaviour within the inner workings of our personality !
Types of perspectives!
- Behavioural perspective: Focuses on the role of the external environment in governing our
actions!
- Humanistic perspective: Emphasis on freewill, personal growth and the attempt to find
meaning in ones existence (self actualisation)!
- Cognitive perspective: Examines the nature of the mind and how mental processes
influence behaviour!
- Sociocultural perspective: Examines how the social environment and cultural learning
influence our behaviour, thoughts and feelings!
- Biological perspective: How brain processes and other bodily functions regulate behaviour !
Methods of study!
- Observational methods of study: Observations of a normal environment !
- Strengths: Naturalistic and unobtrusive (you blend in with them), good descriptive data able
to be observed and recorded!
- Weaknesses: Observer bias, participant self-consciousness (they may act differently as a
result)!
- Use: For information that requires observation and description!
- Case study: Intensive examination of a specific person or situation!
- Strength: Detailed descriptive analysis!
- Weakness: May not be generalisable!
- Use: Studies of new, complex or rare phenomena!
- Survey: Asking people a standard set of questions!
- Strengths: Gathers large amounts of data, quick and inexpensive!
- Weaknesses: Sampling errors, less detail, poorly phrased questions and response bias!
- Use: Learning about opinions !
- Correlational study: Examining relationships between variables!
- Strength: Allows you to test predictions and evaluate theories!
- Weaknesses: Confirmation bias, cannot confirm casual relationships - Just because
something’s correlated doesn’t mean its casual!
- Use: Good at investigating ethically problematic questions, good at suggesting new
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hypotheses !
- Possibilities with correlation!
- X and Y are correlated!
- Bi-directionality problem: Does X cause Y or does Y cause X!
- Third variable problem: There is no direct correlation between X and Y!
- Experiments: Manipulation of an independent variable to see its effects on a dependent
variable (must have a theory)!
- Strength: A cause-effect relationship can be established!
- Weakness: Confounds may present valid conclusions (misinterpretation)!
- Use: Testing treatments !
Characteristics of a good theory!
- Organises known facts and gives rise to additional hypotheses that are testable!
- Incorporates existing knowledge within a broad framework - organises information in a
meaningful way!
- Is testable - It generates a hypothesis whose accuracy can be evaluated by gathering new
evidence!
- Predictions made by the theory are supported by the findings of new research!
- Conforms to the ‘Law of parsimony’ - Simpler theory is preferred
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* HOWEVER, EVEN WHEN A THEORY IS SUPPORTED BY MANY SUCCESSFUL
PREDICTIONS, IT IS NEVER REGARDED AS THE ABSOLUTE TRUTH - YOU CANNOT PROVE
SOMETHING - FUTURE OBSERVATIONS MAY CONTRADICT IT (PROGRESSION OF
SCIENCE)*! !
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Threats to the validity of research!
- Confounding variables: When two variables are intertwined in a way that we can’t
determine which one has influenced a dependent variable !
- Placebo effects: Changes in behaviour because of expectations!
- Experimenter expectancy effects: The subtle and unintentional ways a researcher can
influence participants to respond in a way consistent with the researcher’s hypothesis!
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*Double blind procedure: Both experimenter and participant are kept blind as to which
experimental condition the participant is in*!
- Generalising findings: Drawing conclusions without asking further questions !
*External validity: The degree to which the results of a study can be generalised to other
populations, settings and conditions*!
*Replication: Repeating a study to see if the original results can be replicated*!
LEARNING !
- Learning: A process that results in a relatively consistent change in behaviour or behaviour
potential and is based on experience!
- Experience: Taking in information and making responses that affect the environment !
- Performance is the best measure of learning!
- Learning is consistent over different circumstances but it does not necessarily mean permanent
change - If you stop practicing a skill, performance declines but the skill is much more easily
learned the second time !
- Learning happens when a response is influence by the lessons of memory!
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Non-associative learning!
- Habituation: Response to a stimuli decreases with frequent presentation!
Sensitisation: Response to a stimuli increases with frequent presentation !
- Generally short lived - soon gives way to habituation !
- Generally associated with stronger/important stimuli !
CLASSICAL CONDITIONING: The pairing of a neutral stimuli with an unconditioned stimuli
(requires expectancy)!
- Unconditioned stimulus (UCS): A stimulus that elicits a response without learning!
- The unconditioned response (UCR) is the
automatic reaction to this stimulus!
- Conditioned stimulus (CS): A stimulus able to elicit
a conditioned (learned) response, similar to the
UCR!
- Before conditioning: The participant has no
response to the neutral stimuli but an automatic
response to the unconditioned stimuli !
- During conditioning: The neutral stimuli becomes
a conditioned stimuli —> It elicits an anticipatory
response
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- Factors affecting the pairing of an UCS with a
neutral stimulus!
- The timing between the two stimulus !
- The reliability of co-occurrence - Confidence in
predictability !
- The strength of the UCS - Some things have a greater impact on others!
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- Attention: The individual must be aware of both stimuli!
- The UCS must match the CR - Some combinations are better than others!
After conditioning!
- Extinction: After a period of time of the CS being presented without the UCS, the acquired
behaviour fades over time - but although the response is gone, the learning is still there, it is
just suppressed!
- Reconditioning: Learning is faster after an initial acquisition!
- Spontaneous recovery: Sudden response!
- After greater training, there is greater ability to discriminate !
OPERANT CONDITIONING: A type of learning in which an individual’s behaviour is modified by
it’s consequences and results!
- Reinforcement: Increases the frequency of an operant behaviour by presenting a pleasant
stimulus or by removing an unpleasant one !
- Law of effect: If a response in a particular situation is followed by a pleasant or satisfying
consequence, it will be strengthened !
- Encourages and teaches you how to do
things right but is relatively slow!
- Punishment: Reduces the frequency of an
operant behaviour by presenting an
unpleasant stimulus or by removing a
pleasant one !
- Only teaches you what’s wrong!
- May result in negative feelings towards
the punisher!
- Has more negative consequences!
- Suppresses behaviour but does not erase
it!
- Faster and more powerful!
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Methods of operant conditioning!
- Shaping: Guiding someone to a desired behaviour you want to see by reinforcing
successive approximations of the target behaviour!
- Continuous reinforcement schedule: Reinforcement is given every time a particular
response occurs !
- Predictable with very fast learning but very fast extinction!
- Partial reinforcement schedule: Reinforcement is given some of the time!
- Fixed ratio: Fixed number of responses before reinforcement - very effective!
- Variable ratio: Varying number of responses before reinforcement - unpredictable!
- Fixed-interval: Fixed amount of time before reinforcement - Response decreases until
the person anticipates the time is near!
- Variable-interval: Varying amount of time before reinforcement !
Delay and size of reinforcement!
- Reinforcement is strongest when it directly follows the response!
- The bigger the reinforcement, the bigger the effect!
Partial reinforcement extinction effect: Continuous reinforcement results in fast extinction
whereas partial reinforcement results in slow extinction!
- Operant extinction: The weakening and eventual disappearance of a response because it is no
longer reinforced!
- Primary reinforcements: Have a direct effect e.g. food and water!
- Secondary reinforcements (conditioned reinforcements) : Learnt effects e.g. money and
praise
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THE BRAIN AND BEHAVIOUR!
NEURONS!
- Neurons: Specialised cells which are the basic building blocks of the nervous system !
- Each neuron has 3 main parts!
- Cell body/soma: Contains the biochemical structures needed to keep the neuron alive - its
nucleus carries the genetic information that
determines how the cell develops and functions!
- Dendrites: Specialised receiving units that collect
messages from neighbouring neurons ands end
them on to the cell body where it is then combined
and processed!
- Axon: Only extends from one side of the cell
body. It conducts electrical impulses away from
the cell body to other neurons, muscles or glands.
It is the output part of a neuron and branches out
at its end to form a number of axon terminals these axon terminals may connect with dendrites
from numerous neurons!
- All parts of a neuron are covered by a protective
membrane that controls the exchange of chemical substances between the inside and outside of
the cell!
- Neurons generate electricity that creates nerve pulses!
- Neurons release chemicals that allow them to communicate with each other and with muscles
and glands!
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Glial cells: Support neurons in their function!
- Don’t send or receive nerve impulses but surround neurons and hold them in place!
- They manufacture nutrient chemicals that neurons needs !
- They absorb toxins and waste materials!
- During prenatal development, they send out long fibres that guide newly divided neurons to
their targeted places in the brain!
ACTION POTENTIALS/NERVE IMPULSES!
- How do nerve impulses/action potentials occur?!
1. In a resting state, the neurons sodium and potassium channels are closed!
• The concentration of Na+ ions is 10 times greater outside the neuron than inside it!
2. When stimulated, nearby sodium channels open up
attracting the sodium ions to the negative protein ions
inside, flooding into the axon creating a state of
DEPOLARISATION!
3. In a reflex action to restore the resting potential, the
cell closes its sodium channels and positively charged
potassium ions flow out, restoring the negative resting
potential !
4. Eventually, the excess sodium ions flow out of the
neuron and the escaped potassium ions are
recovered!
5. The original ionic balance is restored and the neuron
is again at rest!
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Depolarisation: Becomes more positive than it was before!
- Re-polarisation: Becomes more negative than it was
before (hyperpolarises it)!
- Action potential: Depolarisation and re-polarisation occurs
in less than 0.002 seconds!
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Therefore, action potentials occur due to a flow of ions in and out through the cell membrane,
reversing the charge of there eating potential !
- In salty fluid outside the neuron, there are positively charged sodium ions and negatively
charged chloride ions!
- Inside the neuron are large negatively charged protein molecules and positively charged
potassium ions !
- The high concentration of sodium ions in the fluid outside the cell, together with the negatively
charged protein ions inside results in an uneven distribution of positive and negative ions !
- The internal difference of around 70mV is the neurons RESTING POTENTIAL!
- Polarisation: When the neuron is at rest!
- For a neuron to function properly, sodium and potassium ions must enter and leave the
membrane at just the right rate!
If you just generate an action potential and attempt to send it down the axon, the charge is not
great and fast enough to make it to the next neuron!
- The solution - One form of help comes from the oligodendrocytes (a type of glial cell) that
forms the myelin sheath which wraps itself around the axon and prevents ions from flowing
out - the axon has pores!
Action potentials occur at an uniform and maximum intensity or do not occur at all!
Once an action potential occurs at any point on the membrane, its effects spread to adjacent
sodium channels and the action potential
flows down the length of the axon to the
axon-terminals !
Absolute refractory period: The period
immediately after an impulse passes a point
along the axon as the K+ ions flow out of the
interior!
- During this period, the membrane not
excitable and cannot discharge another
impulse - This places an upper limit of
approximately 300 impulses per second
for humans !
Graded potentials: Changes in the negative
resting potential that do not reach the 50
millivolt action potential threshold - Under
certain circumstances, graded potentials
created by several neurons can add up to
trigger an action potential in an adjacent
neuron!
NEURON COMMUNICATION: SYNAPTIC TRANSMISSION!
- Synaptic space: A tiny gap between the axon
terminal and the next neuron !
- Neurotransmitters: Chemical substances
that carry messages across the synaptic
space to other neurons, muscles or glands
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1. Synthesis: The transmitter molecules are
formed inside the neuron!
2. Storage: In synaptic vesicles, chambers
within the axon terminals!
3. Release: When an action potential comes
down the axon, these vesicles move to the
surface of the axon terminal and the
molecules are released into the fluid-filled
space between the axon of the presynaptic
(sending) neuron and the membrane of the postsynaptic (receiving) neuron!
4. Binding: The molecules cross the synaptic space and bind themselves to receptor sites - large
protein molecules embedded in the receiving neuron’s cell membrane - When a transmitter
molecule binds to a receptor site, a chemical reaction occurs that will either result in excitation
or inhibition of the receiving neuron. Excitatory: Sodium channels open up depolarising the cell,
creating an action potential or a graded potential. Inhibitory: Positive potassium ions flow out or
negative chloride ions flow in, increasing the neurons negative potential and making it harder to
fire the neuron !
5. Deactivation: Some transmitter molecules are deactivated by other chemicals located in the
synaptic space or they will reuptake - the transmitter molecules are taken back to the
presynaptic axon terminals
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HOW TO MAP ACTIVITY!
- Figuring out which part of the brain is active during a task!
- (GOOD FOR WHEN) Electrical activity —> Electroencephalogram (EEG): Records electrical
fields generated by groups of neurons firing action potentials —> Provides a gross estimate of
overall brain activity!
- Subdural recording : Beneath the scalp recording, on the actual brain!
- Scalp recording: above the scalp!
- (GOOD FOR WHERE) Blood flow: If a part of the brain is active, more blood will flow there!
- A bit of delay before the blood flows there, which is why ‘when’ is not so good when using
blood flow!
- Functional magnetic resonance imagining (FMRI) - Images protons that are in hydrogen
that are part of water molecules in the bloodstream —> Measures whole brain activation!
- As the blood flows, so does the oxygen and therefore the hydrogen and therefore the
protons !
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THE NERVOUS SYSTEM!
- Is the body’s control centre!
- Sensory neurons: Carry input messages from the sense organs to the spinal cord and brain!
- Motor neurons: Transmit output impulses from the brain and spinal cord to the body’s muscles
and organs!
- Interneurons: Perform connective or associative functions within the nervous system - link the
input and output functions!
- Peripheral nervous system: Contains all the neural structures that lie outside of the brain and
spinal cord !
- Enables us to sense what is going on inside and outside our bodies and to respond with
muscles and glands !
- Somatic nervous system: Consists of sensory neurons that are specialised to transmit
messages from sensory receptors and motor neurons that send messages from the brain and
spinal cord to the muscles that control voluntary movement !
- Autonomic nervous system: Regulates the body’s internal environment. It is largely concerned
with involuntary functions and many aspects of motivation, emotional behaviour and stress!
- Parasympathetic: Generally inhibits e.g. Contracts pupils!
- Sympathetic: Generally activates e.g. Dilates pupils!
- The central nervous system: Contains the brain and spinal cord !
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THE FUNCTIONS OF DIFFERENT PARTS OF THE BRAIN!
- The hindbrain!
- Brain stem: Supports vital life functions!
- Medulla: Plays an important role in vital body functions such as
heart rate and respiration !
- Pons: Lies just above the medulla and carries nerve impulses
between higher and lower levels of the nervous systems - Also
helps in regulating sleep - also helps to control vital functions!
- Cerebellum: Concerned with muscular movement coordination and
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also plays a role in learning and memory !
- Regulates complex, rapidly changing movements
that require precise timing !
The midbrain!
- Contains sensory (visual and auditory systems) and
motor (control eye movement) neurons !
- Reticular formation: Plays a central role in
consciousness, sleep and attention!
- Ascending portion: Sends input to higher regions
of the brain to alert it!
- Descending portion: Higher brain centres can
either admit or block out sensory input!
- Without stimulation of higher brain regions, sensory
messages do not register in conscious awareness!
- Attention: Some inputs have to be toned down or completely
blocked out or w’d be overwhelmed by the stimulation!
The forebrain!
- The brain’s most advanced portion!
- Cerebrum: Consists of two large hemispheres - a left and a right
side - covered by the cerebral cortex and connected by the
corpus callosum !
- Thalamus: Organises inputs from sensory organs and routes
them to the appropriate areas of the brain!
- Hypothalamus: Tiny groups of neuron cell bodies that play a
major role in many aspects of mitigation and emotion, including
sexual behaviour, temperature regulation, sleeping, eating,
drinking and aggression !
- Has important connections with the endocrine system - hormone-producing glands!
- Also involved in experiences of pleasure and displeasure !
- Limbic system: Memory, emotion and goal-directed behaviour - helps to coordinate
behaviours needed to satisfy motivational and emotional urges that arise in the hypothalamus!
- Hippocampus: Forms and retrieves memories !
- Amygdala: Organises motivational and emotional response patterns - particularly those
linked to aggression and fear !
The different lobes!
- Frontal lobe: Contains most of the dopamine-sensitive
neurons in the cerebral cortex - Associated with reward,
attention, short term memory tasks, planning and motivation.
Site of human qualities as self awareness, planning, initiative
and responsibility !
- Damage can result in an inability to plan and carry out a
sequence of actions and also an inability to correct actions
that are clearly erroneous and self-defeating. It is also
involved in emotional experience !
- Prefrontal cortex: Goal setting, judgement, strategic
planning and impulse control!
- Broca’s area in the frontal lobe: Production of speech
through it connections with the motor cortex region that
controls the muscles used in speech - can understand but can’t speak!
- Motor cortex: Controls the muscles involved in voluntary body movements - each
hemisphere governs moment on the opposite side of the body due to the nerve tracts
crossing over!
- Temporal lobe: Involved in the retention of visual memories,
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processing sensory input, comprehending language, storing new
memories, emotion and deriving meaning.!
- Wernicke’s area in the temporal lobe: Speech comprehension Damage leaves patients unable to understand written or spoken
language!
- Parietal lobe: Integrates sensory information, the main sensory
receptive area for the sense of touch and the dorsal stream of the
visual system.!
- Sensory cortex: Receives input from our sensory receptors !
- Somatic sensory cortex: Receives sensory input that gives rise to our sensations of heat,
touch and cold and to our senses of balance and body movement !
- Occipital lobe: Here messages from the eyes are analysed, integrated and translated into
sight!
MEMORY !
- Memory: The processes that allow us to record, store and later retrieve experiences and
information!
- 3 Stages of Memory!
- Encoding: Getting information into the system by
translating it into a neural code that your brain
processes !
- Storage: Retaining information over time !
- Retrieval: Accessing stored information!
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Three Major Components of Memory!
- Sensory memory: Briefly holds incoming sensory
information - Some information reaches working
memory and long term memory where it is then
mentally represented by visual, phonological,
semantic or motor codes!
- Sensory registers: Subsystems which are the initial information processors!
- Iconic store: Visual sensory register!
- Echoic store: Auditory sensory register - it can hold precise details of a sound for several
seconds !
- Working (short-term) memory: Temporarily stores a limited amount of information and
supports other cognitive functions!
- Memory codes: Mental representations of some type of information or stimulus - They
work to retain information in short-term memory!
- Can be strengthened by repetition !
- Can usually hold no more than five to nine meaningful items at a time !
- Limited capacity system !
- Stores information, actively manipulates it, supports other cognitive functions such as
problem-solving and planning and interacts with long term memory !
- Components of short-term memory!
- Phonological loop: Stores mental representations of sound !
- Visuospatial sketch-pad: Stores visual and spatial information !
- Episodic buffer: Provides a temporary storage space where information from long-term
memory and from the other two components can be integrated, manipulated and made
available for conscious awareness !
- Central executive: Directs the overall action - Plans and controls sequences of actions
that need to be performed, divides and allocates attention to the other subsystems and
integrates information within the episodic buffer !
- Long-term memory: Stores large amounts of information for up to a lifetime!
- Durable stored memories!
- Unlimited storage capacity!
- Serial position effect: The ability to recall an item is influenced by the item’s position in a
series !
- Primacy effect: Superior recall of the earliest items!
- Cause: As the first view items enter short-term memory, we can quickly rehearse them
and transfer them into long-term memory. However, as the list gets longer, short-term
memory rapidly fills up and there are too many words to keep repeating before the
next word arrives - therefore it is too hard to rehearse and less likely to get transferred
into long-term memory !
- Recency effect: Superior recall of the most recent items!
- Last few items normally linger in short-term memory and have the benefit of not being
bumped out by new information
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Stages in memory (elaborated)!
- Encoding!
- Effortful processing: Involves intention and conscious attention!
- Automatic processing: Occurs without intention and requires minimal effort!
- Memory codes: Mental representations
of some type of information or stimulus!
- Visual codes (structural
encoding): Mental images!
- Phonological codes: Sound!
- Semantic codes: Meaning!
- Motor codes: Physical actions!
- Deep processing enhances memory !
- Elaborative rehearsal provides
deeper processing than
maintenance rehearsal!
- Maintenance rehearsal: Simple,
rote repetition - keeps information
active in working memory !
- Elaborative rehearsal: Focusing
on the meaning of information or expanding it in some way !
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Mnemonics: The art of improving memory!
- Mnemonic devices: Reorganise information into more meaningful units and provide extra cues
to help retrieve information from long-term memory!
- Mnemonic devices!
- Dual coding: Encoding information using both verbal and visual codes - better chance of
one remembering it!
- Hierarchies: Organising material into a hierarchy - layers - each category serves as a
cue that triggers our memory for the items below it !
- Chunking: Combining individual items into larger units of meaning!
- Method of loci: A memory aid that associates information with mental images of physical
locations - imagining a place and linking information with it !
- Schemas: A mental framework - An organised pattern of thought - about some aspect of
the world!
- Linking things together !
- Mean-ends analysis: Dividing goals into subgoals!
- Within subgoals, there are different means to get to the subgoals!
- Working backwards: Retracing steps
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- Storage!
- Associative network: A massive network of associated ideas and concepts !
- Priming: The activation of one concept by another - Forming a network !
- Declarative LT memories: Involve factual knowledge and include episodic and semantic
memories - They are called that because to demonstrate our knowledge, we have to declare it
- tell other people what we know !
- Episodic memory: Our store of knowledge concerning personal experiences - when,
where and what happened in the episodes of our lives !
- Semantic memory: General factual knowledge about the world and language - including
memory for words and concepts !
- Procedural LT memory: Is reflected in skills and action - Non-declarative !
- Skills that are expressed doing things in particular situations !
- Explicit LT memory: Involves conscious or intentional memory retrieval - When you
consciously recognise or recall something !
- Recognition: Deciding whether a stimulus is familiar !
- Recall: Spontaneous memory retrieval !
- Implicit LT memory: Influences our behaviour without conscious awareness
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- Retrieval!
- Retrieval cues: Stimuli that activate information stored in long-term memory!
- Is more likely when we have multiple, self-generated and distinctive cues !
- Distinctive cues: Ones that stand out from the rest !
- People typically remember emotion arousing stimuluses better!
- Triggers the release of stress hormones - Causing neurotransmitters to release amygdala,
helping to encode the emotional aspects of experiences into longer-term memories !
- Emotional arousal has been found to enhance autobiographical memories - Recollections
of personally experienced events that make up the stories of our lives!
- The ability to retrieve memories is also influenced by environmental, physiological and
psychological factors !
- Encoding specificity principle: Memory is enhanced when conditions present during
retrieval match those that were present during encoding !
- Context-dependent memory: Easier to remember something in the same environment in
which it was originally coded!
- State-dependent memory: Our ability to retrieve information is greater when our internal
state at the time of retrieval matches our original state during learning !
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Forgetting!
- Sometimes occurs because we never encoded it into long-term memory in the first place!
- Decay theory: With time and disuse, the long-term physical memory trace in the nervous
system fades away !
- Proactive interference: When material learned in the past impairs recall of newer material!
- Retrograde interference: When newly acquired material impairs the ability to recall information
learned at an earlier time!
- Occurs because it takes time for the brain to convert short-term memories into long-term
memories!
- Theory 1: When new information is entered into the system, it can disrupt the conversion
of older information into long-term memories !
- Theory 2: Confusion occurs when there is competition among retrieval cues due to
different memories being associated with similar or identical retrieval cues !
- Repression: Forgetting anxiety-arousing material through an unconscious process of
motivated forgetting - repression!
- Retrograde amnesia: Memory loss for events that occurred before amnesia!
- Anterograde amnesia: Memory loss for events that occur after amnesia !
- Dementia: Impaired memory and other cognitive deficits that accompany brain degeneration
and interfere with normal functioning
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- Misinformation and the brain!
- Misremembering events in a way that fits with our pre-existing concepts may lead us to recall
events that never occurred !
- Occur when memory is distorted by misleading post event information - This may occur
because of source confusion - The tendency to recognise something to us as familiar but to
forget where we encountered it!
- Significant parts of the brain!
- Frontal lobe: Plays a key role in performing executive functions of working memory!
- Hippocampus: Helps consolidate long-term memories!
- Amygdala: Encodes emotionally arousing aspects of events!
- Cerebellum: Helps form procedural memories
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SENSATION AND PERCEPTION!
- Steps in perception!
1. Transduction occurs!
2. Specialised neurons break down and analyse the various features of the stimulus!
3. These numerous stimulus features are reconstructed into a neural representation that is
then compared with previously stored information - This matching of a new stimulus with
our internal storehouse of knowledge
allows us to recognise the stimulus and
give it meaning!
4. We then consciously experience a
perception !
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Sensation: The stimulus-detection process
by which our sense organs respond to and
translate environmental stimuli into nerve
impulses that are sent to the brain!
- Perception: Making sense of what our
senses tell is - is the active process of
organising this stimulus input and giving it
meaning !
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Sensory process!
- The sensory equipment of any species is an
adaptation to the environment in which it lives!
- Transduction: The process whereby the characteristics of a stimulus are converted into nerve
impulses !
- Absolute threshold: The lowest intensity at which a stimulus is detected 50% of the time (thus
the lower the absolute threshold, the greater the sensitivity)!
- The concept of a fixed absolute threshold is inaccurate because there is no single point on
that separates non-detection from detection of a stimulus - There is instead a range of
uncertainty and people se their own decision criterion!
- Decision criterion: A standard of how certain they must be that a stimulus is present
before they will say they detect it !
- Signal detection theory: Concerned with factors that influence decisions about whether or
not a stimulus is present !
- Subliminal stimuli: Very weak stimuli that do not register in awareness but can influence
behaviour !
- The difference threshold: The smallest difference between two stimuli that people can perceive
50% of the time !
- Sensory adaptation/habituation: The diminishing sensitivity to an unchanging stimulus !
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Vision!
- Normal stimulus for vision: Electromagnetic energy or light waves!
- Cornea: Light waves enter here - A transparent protective
structure at the front of the eye!
- Pupil: Behind the cornea - Has an adjustable opening that
can dilate or constrict to control the amount of light that
enters the eye !
- The pupil’s size is controlled by muscles in the coloured
iris that surrounds the pupil !
- Lens: An elastic structure that becomes thinner to focus on
distant objects and thicker to focus on nearby objects!
- The lens focuses the visual image on the retina!
- The lens reverses the image from right to left and top to
bottom when it is projected upon the retina, but the brain
reverses the visual input into the image that we perceive !
- Retina: A multilayered light-sensitive tissue at the rear of the
fluid filled eyeball!
- In short-sighted people, the lens focuses the visual image
in front of the retina or too near the lens !
- Long-sightedness occurs when the lens does not thicken enough and
therefore the image is focused on a point behind the retina or too far
from the lens !
- Rods and cones form the rear layer of the optic nerve and their light
sensitive ends point away from the direction of the entering light so
that they only receive only a fraction of the light energy that enters the
eye!
- Rods: Function best in dim light - Are black and white brightness
receptors !
- Are more sensitive to light than cones but do not give rise to colour
sensations !
- The periphery of the retina contains mainly rods!
- Cones: Colour receptors that function best in bright illumination !
- Cones decrease in concentration the farther away they are from the centre of the retina!
- There are more rods than cones in the human eye !
- Fovea: A small area in the centre of the retina that contains no rods but many densely packed
rods - Have their own private line to a single bipolar cell - Thus we can see fine detail well !
- Rods and cones have synaptic connections with bipolar cells - These synapse with a layer of
about 1 million ganglion cells who's axons are collected into a bundle to form the optic nerve !
- Allow the rods and cones to send their messages to the brain !
- Rods and cones translate light waves into nerve impulses through the action of protein
molecules called photopigments !
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Colour vision!
- Young-Helmholtz Trichromatic theory: There are three types of colour receptors in the retina each of these receptor classes sends messages to the brain, based on the extend to which they
are activated by the light energy’s wavelength. The visual system then combines the signals to
re-create the original hue - If all three cones are equally activated, a pure white colour is
perceived !
- However, did not explain our perception of yellow as people with red-green colour blindness
could still perceive it!
- Hering’s Opponent-process theory: Proposed that each of the three cone types responds to two
different wavelengths!
- One type responds to blue or yellow, another to red or green and a third to black or white !
- Dual-process theory (today’s): There are three kinds of cones that are sensitive to different
wavelengths with opponent-process mechanisms that occur further along the visual system!
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Audition!
- Sound waves: A form of mechanical energy - Stimulates
our sense of hearing!
- Sound: Pressure waves in a medium!
- Frequency: Number of sound waves, or cycles, per
second!
- Measured in hertz (Hz!
- The higher the frequency, the higher the perceived
pitch!
- Amplitude: Vertical size of the sound waves - The amount
of compression and expansion of the molecules in the
conducting medium !
- Differences in amplitude are expressed in decibels (dB) - A measure of the physical pressures
that occur at the eardrum - The higher the decibels, the louder the sound is!
- Pressure waves get translated into nerve impulses !
- Stages in sound!
1. Auditory Canal!
2. Eardrum - A membrane that vibrates in
response to the sound waves!
3. Middle ear - A cavity housing three tiny bones The vibration of these bones amplifies the
sound waves!
4. This sets the fluid inside the cochlea into
motion!
5. The fluid waves that result vibrate the basilar
membrane and the tectorial membrane,
causing a bending of the hair cells in the organ
of Corti!
6. The bending of the hair cells trigger the release
of neurotransmitters into the synaptic space
between the hair cells and the neurons of the auditory nerve, resulting in here impulses that
are sent to the brain !
- Inner ear: Contains the cochlea - A coiled, snail-shaped tube
around 3.5cm long that is filled with fluid and contains the
basilar membrane (a sheet of tissue that runs its length)!
- Resting on the basilar membrane is the organ of Corti Contains tiny hair cells that are the actual sound receptors !
- The tips of the hair cells are attached to the tectorial
membrane that overhangs the basilar membrane along the
entire length of the cochlea !
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The auditory system transforms the sensory qualities of
wave amplitude and frequency (experienced by us as
loudness and pitch) into the language of nerve impulses!
High-amplitude sound waves cause the hair cells to bend
more and release more neurotransmitter substance at the point where they synapse with
auditory nerve cells, resulting in a higher rate of firing within the auditory nerve !
- Also, some receptor neurons have higher thresholds than others, so that they will only fire
when hair cells bend considerably in response to an intense sound !
Place theory of pitch perception: The specific point in the cochlea where the fluid wave peaks
and most strongly bends - The hair cells serve as a frequency coding cue!
The auditory cortex has a tonal-frequency map that corresponds to specific areas of the cochlea!
- By analysing the specific location of the cochlea from which auditory nerve impulses are being
received, the brain can code high frequency sounds !
The nervous system uses information concerning the time and intensity differences of sounds
arriving at the two ears to locate the source of sounds in space!
- Sounds arrive first and loudest at the ear closest to the sound !
- Conduction deafness: Problems with the mechanical system that transmits sound waves to the
cochlea - e.g A punctured eardrum !
- Nerve deafness: Damaged receptors within the inner ear or damage to the auditory nerve itself !
- Cannot be helped by a hearing aid because the problem does not lie in the transmission of
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sound waves to the cochlea !
Taste and smell!
- Gustation: The sense of taste!
- Olfaction: The sense of smell !
- Both receptors are sensitive to chemical molecules rather than to some form of energy !
- Senses are very intertwined !
- Taste buds: chemical receptors concentrated along the tip, edges and back surface of the
tongue !
- Sweet, sour salty and bitter!
- The receptors for smell are long cells that project through the
lining of the upper part of the nasal cavity and into the mucous
membrane !
- Olfactory receptors have structures that resemble
neurotransmitter binding sites on neurons !
- The receptors that fire send their input to the olfactory bulb - a
forebrain structure immediately above the nasal cavity !
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Tactile senses!
- Touch: Important for sensitivity to extreme temperatures and
to pain!
- Humans are sensitive to pressure, pain, warmth and cold !
- These sensations are conveyed by receptors in the skin and in our internal organs !
- Primary receptors for pain and temperature are the free nerve endings located under the skin!
- Basket cell fibres, situated at the base of hair follicles are receptors for touch and light
pressure!
- The brain can locate sensations because the skin receptors send their messages to the point in
the somatosensory cortex that corresponds to the area of the body where the receptor is located!
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Pain!
- Pain receptors are found in all body tissues except for the brain, bones, hair, nails and non-living
parts of the teeth!
- Free nerve endings in the skin and internal organs respond to intense mechanical, thermal or
chemical stimulation and then send nerve impulses into the spinal cord, where sensory tracts
carry pain information to the brain !
- Once in the brain, the sensory information about pain intensity and location is relayed by the
thalamus to the somatosensory and frontal areas of the cerebral cortex !
- Other tracts from the thalamus direct nerve impulses to the limbic system - involved in
motivation and emotion !
- Thus pain has both a sensory and an emotional component !
- Suffering: Painful sensations and a negative emotional response present!
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Spinal and brain mechanisms!
- Gate control theory: The experience of pain results from the opening and closing of gating
mechanisms in the nervous system!
- Events in the spinal cord can open a system of spinal cord ‘gates’ and allow the nerve
impulses to travel toward the brain !
- However, other sensory input can partially or completely close the gates and blunt our
experiencing of pain !
- Nerve impulses in fibres descending from the brain can also influence the spinal gates increasing or decreasing the flow of pain stimulation: Central control mechanism!
- Allows thoughts, emotions and beliefs to influence the experience of pain and helps explain
why pain is a psychological phenomenon as well as a physical one!
- Glial cells are also involved in the creation and maintenance of pathological pain !
- Glial cells become activated by immune challenges and by substances released by neurons
!
within the pain pathway.They then amplify pain by releasing cytokines (messenger molecules)
that promote inflammation !
The endorphins!
- Opiates such as opium, morphine and heroin have been used to relieve pain !
- They strongly affect the brain’s pain and pleasure systems !
- They lock into specific receptor sites in brain regions associated with pain perception !
- Endorphins: Natural opiates produced by the nervous system !
- Endorphins exert their effects by inhibiting the release of neurotransmitters involved in the
synaptic transmission of pain impulses from the spinal cord to the brain !
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The body senses!
- Kinaesthesis: Feedback about our muscles and joints positions and movements!
- Kinaesthetic receptors are nerve endings in the muscles, tendons and joints !
- Helps us coordinate movements !
- Vestibular sense: The sense of body orientation or equilibrium!
- Vestibular receptors: Located in the vestibular apparatus of the inner ear !
- Vestibular sacs and canals help us respond to the position of the body and tell us if we are
upright or tilted and if we’re accelerating or decelerating (respectively)!
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PERCEPTION: THE CREATION OF EXPERIENCE!
- To create our perceptions, the brain carries out two different kinds of processing functions!
- The bottom-up processing: The system takes in individual elements of the stimulus and
then combines them into a unified perception - e.g. Visual system !
- The top-down processing: Sensory information is interpreted in light of existing knowledge,
concepts, ideas and expectations!
- Shadowing: Blocking out information to concentrate on one stimuli!
- Inattentional blindness: The failure of unattended stimuli to register in consciousness !
- Attention is affected by both the nature of the stimulus and by personal factors!
- Stimulus characteristics that attract our attention include intensity, novelty, movement,
contrast and repetition !
- Sexually oriented stimuli are especially attention-grabbing !
- Our motives and interest act as powerful filters and influence which stimuli in our environment
we will notice !
- People are attentive to stimuli that have relevance to their well-being due to their biological
survival value !
- e.g. Is it dangerous or not?!
- Gestalt principles !
- Figure-ground relations: Our tendency to organise stimuli into a central or foreground figure
and a background !
- In vision: Usually the object infront or on top of what we
perceive as background is the central figure!
- In sound: We hear melodies surrounded by other chords or
harmonies!
- People group and interpret stimuli in accordance with four gestalt
laws of perceptual organisation: Similarity, proximity, closure and
continuity !
- Similarity: When parts of a configuration are perceived as
similar, they will be perceived as belonging together!
- Proximity: Elements that are near each other are likely to be
perceived as part of the same configuration!
- Closure: People tend to close the open edges of a figure or fill
in gaps in an incomplete fire, so that their identification of the form is more complete than
what is actually there!
- Continuity: People link individual elements together so they form a continuous line or
pattern that makes sense !
- Perceptual schema: A mental representation or image containing the distinctive and most
prominent features of a person, object, event or other.!
- Perceptual set: A readiness to perceive stimuli in a particular way !
- Perceptual constancies allow us to recognise familiar stimuli under varying conditions!
- Shape constancy, brightness constancy, size constancy !
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Depth, movement and distance!
- Monocular depth cues !
- Patterns of light and shadow!
- Linear perspective: Perception that parallel lines
converge or angle toward one another as they
recede into the distance!
- Interposition: Objects closer to us may cut off
part of our view of more distant objects!
- Texture: Fineness of it!
- Clarity: Closer objects are more clearly seen!
- Relative size: In similar sized objects, if one is
smaller, it’s further away!
- Parallax: When we’re moving, nearby objects
move faster in the opposite direction than faraway
ones!
- Binocular disparity: Each eye sees a slightly different
image!
- Binocular depth cues!
- Convergence: Feedback from the muscles that turn your eyes inward to view a close object!
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Perception of movement!
- The movement of an image cross the retina is the
primary cue for perceiving motion!
- Stroboscopic movement: Illusion of smooth movement !
- e.g. A line of lights flashes quickly one by one in
order from left to right will be perceived as smooth
movement!
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Illusions: False perceptual hypothesis!
- Illusions: Compelling but incorrect perceptions!
- Distance cues can sometimes fool us !
- Perceptual constancies help produce many illusions !
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Experience, Critical Periods and Perceptual Development!
- Development of sensory and perceptual systems results from the
interplay of biological and experiential factors !
- Genes program this biological development!
- Environmental experiences also influence the development!
- A persons culture and context determines how they perceive
things!
- Critical periods: Certain kinds of experiences must occur if
perceptual abilities and the brain mechanisms that underlie them
are to develop normally !
- If a critical period passes without the experience occurring, it is too late to undo the deficit that
results!
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GENE, ENVIRONMENT AND BEHAVIOUR !
- Whether raised together or apart, the identical twins were far more similar in personality and
intelligence test scores than siblings (including non-identical twins) raised in the same families!
- Genotype: The specific genetic makeup of an individual!
- Phenotype: An individual’s observable characteristics!
- Can be affected by other genes and the environment !
- Chromosome: A double-stranded and tightly coiled molecule of
DNA!
- Genes: The biological units of heredity !
- Alleles: Alternative forms of a gene that produce different
characteristics!
- Dominant genes: The particular characteristic that it controls will
be displayed!
- Recessive genes: The characteristic will not show up unless both
genes inherited from both parents are also recessive !
- Polygenic transmission: A number of gene pairs combine their
influences to create a single phenotypic trait !
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Behaviour genetics!
- Behaviour genetics: Study how heredity and environmental and social factors influence
psychological characteristics!
- Relative influence of genetics, the environment and social factors in accounting for individual
differences in behaviour !
- Studies show that the more similar people are genetically, the more similar they are likely to be
psychologically !
- Family studies: Researchers study relatives to determine if a genetic similarity is related to
similarity on a particular trait !
- Adoption studies: People who were adopted early in life are compared on some characteristic
with both their biological parents and with their adoptive parents !
- If they are found to be more similar to a biological parent - a genetic influence on that trait is
indicated!
- If they are found to be more similar to their adoptive parents - environmental factos are judged
to be more important for that characteristic!
- Twin studies: Compare trait similarities in identical and fraternal twins!
- Fraternal twins: 50% similar genes!
- Maternal twins: 100% similar genes!
- Identical twins may be more similar to each other due to them having a more similar
appearance, therefore getting treated more alike, sharing a more similar environment - may
partially account for greater behavioural similarity !
- Psychological characteristics have a notable genetic contribution!
- Adopted children are typically found to be more similar to their biological parents on this
measure !
- Identical twins also seem to be more similar to one another than fraternal twins, even if they
were separated early in life and reared in different environments !
- However, identical twins raised in the same environment are more similar than those raised
apart, indicating that the environment also makes a difference!
- Heritability coefficient: The extent to which the differences, or variation, in a specific phenotypic
characteristic within a group of people can be attributed to their differing genes!
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Adapting to the environment: The role of learning!
- Adaptive significance: How behaviour influences an organism’s chances of survival and
reproduction in its natural environment!
- Fixed action pattern: An unlearned response automatically triggered by a particular stimulus !
- Shared environment: People who reside in these experience many of their features in common!
- Unshared environment: Experiences that are unique to us!
- Humans and other animals can learn which stimuli are important and which responses are likely
!
to result in goal attainment - this allows them to regular their behaviour and adapt to the
environment !
Behaviour genetics, intelligence and personality!
- Intelligence has a strong genetic basis!
- Shared family environment and education experiences are also importantly linked to intelligence !
- Personality has a genetic contribution but is not as strong as that for intelligence !
- Shared family environment has little impact on personality!
- Unshared individual experiences are more important environmental determinants of personality!
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Gene-environment interactions!
- Genetic factors may influence how different people experience the same environment!
- The environment can influence how genes express themselves!
- Reaction range: The range of possibilities that the genetic code allows !
- Ways genetic factors can influence the environment!
- Genes shared by parents and children may be expressed in how the parents behave ad in the
environment they create!
- Evocative influence: A child’s genetically influenced behaviour may evoke certain responses
from others - Genes may produce characteristics that influence how others respond to the
person !
- People may self-select or create environments that are consistent with their genetic
characteristics !
- e.g. Asians like to stick with asians !
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Evolution, culture and behaviour!
- Evolutionary psychology: Biologically based mechanisms sculpted by evolutionary forces as
solutions to the problems of adaptation faced by species !
- Evolution: A change in the frequency of certain characteristics produced by genes within an
interbreeding population over time !
- Interaction between biological, environmental and social factors !
- Some genetic variations arise in a population through mutations - random events and accidents
in gene reproduction during the division of cells !
- Natural selection: Characteristics that contribute to survival and reproductive success will
increase in the population over time because those that lack those characteristics will eventually
die off and are less likely to pass on their genes!
- The products are adaptations - Physical or behavioural changes that allow organisms to
meet recurring environmental challenges to their survival, thereby increasing their
reproductive ability !
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STATES OF CONSCIOUSNESS!
- Consciousness: Our moment-to moment awareness of ourselves and our environment
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- Characteristics of consciousness!
- Subjective and private: Other people can’t know exactly what reality is like for you and vice
versa!
- Dynamic (ever-changing): We drift in and out of various states throughout each day. The
stimuli of which we are aware of cons tangle changes.!
- Self-reflective and central to our sense of self: The mind is aware of its own
consciousness !
- Selective attention: The process that focuses awareness on some stimuli to the exclusion of
others
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- Measuring states of consciousness!
- Self-report measure: People describe their own inner experiences!
- Behavioural measures: Record performance on special tasks!
- Physiological measures: Establishes the correspondence between bodily processes and
mental states
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- Levels of consciousness!
- The freudian viewpoint: Three levels of awareness!
- Conscious: Thoughts and perceptions of which we are currently aware!
- Preconscious: Mental events outside current awareness but can easily be recalled !
- Unconscious: Events that cannot be brought into conscious awareness under ordinary
circumstances - repressed memories !
- The cognitive viewpoint: Conscious and unconscious mental life are complementary forms
of information processing !
- Controlled (conscious) processing: The conscious use of attention and effort!
- Automatic (unconscious) processing: Activities performed without conscious awareness or
effort !
- Facilitates divided attention: The capacity to attend to and perform more than one activity
at the same time
!
- Unconscious perception and influence!
- Visual agnosia: People with visual agnosia could still perform tasks using that part of the
brain which is impaired, unconsciously !
- Blindsight: People that are blind in part of their visual field could still respond to stimuli in that
field !
- Priming: People exposed to a stimulus are influenced in how they subsequently respond to
that same or another stimulus !
- The emotional unconscious: Emotions being influenced by events in the environment of
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which they were not consciously aware of !
Daily biological clocks !
- Circadian Rhythms: Daily biological cycles!
- Most circadian rhythms are regulated by the brain’s suprachiasmatic nuclei (SCN), located in the
hypothalamus !
- SCN neurons have a programmed cycle of activity and inactivity!
- They link to the pineal gland, which secretes melatonin - a hormone that has a relaxing effect
on the body!
- SCN neurons become active during the daytime, reducing the secession of melatonin, raising
body temperature and alertness !
- Our eyes have neural connections to the SCN - the light of day increases SCN activity !
- Seasonal affective disorder (SAD): A cyclic tendency to become psychologically depressed
during certain seasons of the year - SAD tends to begin in autumn or winter when there is less
daylight !
SLEEP AND DREAMING!
- Beta waves: Used to record the brain’s electrical activity when you are awake and alert!
- Alpha waves: Used to record the brain’s electrical activity when you are feeling relaxed and
drowsy and your brain waves slow down!
- Stages in sleep!
- Stage 1: When brain-wave patterns become more irregular and slow
theta waves increase!
- A form of light sleep in which you could easily be awakened !
- Few minutes long!
- Dreams, vivid images and sudden body jerks occur in this stage!
- Stage 2: Sleep spindles occur (1-2- second bursts of rapid brain-wave
activity)!
- Muscles are more relaxed!
- Breathing and heart rate slow down!
- Dreams may occur!
- Harder to waken!
- Stage 3: Very slow and large delta waves appear!
- Stage 3 and 4 are referred to as slow-wave sleep!
- Stage 4: When delta waves dominate the EEG pattern!
- Body is relaxed!
- Activity in various parts of the brain have decreased!
- Hard to awaken !
- May have dreams !
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Stages 1-2-3-4-3-2 occur within 60-90 minutes of going to
sleep until REM sleep begins!
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REM Sleep: Characterised by rapid eye movements,
high arousal and frequent dreaming!
- Every half minute or so, bursts of muscular activity
caused sleepers’ eyeballs to vigorously move back
and forth beneath their eyelids !
- Sleepers awakened from REM period almost always
reported a dream !
- Heart rate quickens, breathing becomes more rapid
and irregular and brain0wave activity resembles that
of active wakefulness !
- Regardless of dream content, men have penile
erections and women experience vaginal lubrication !
- The brain also sends signals, making it more difficult for voluntary muscles to contract !
- REM sleep paralysis: The muscles become paralysed !
- Paradoxical sleep: The body is highly aroused yet it looks like you are sleeping peacefully
because there is so little movement !
- Intense activity in the limbic system structures, such as the amygdala - regulates emotions!
- Association areas near the primary visual cortex are active - may reflect the processing of
visual dream images !
- Decreased activity occurs in regions of the prefrontal cortex - planning and logical analysis may explain why dreams are illogical and bizarre !
Why do we sleep?!
- Sleep and body restoration !
- Restoration model: Sleep recharges our run-down bodies and allows us to recover from
physical and mental fatigue!
- Sleep as an evolved adaptation!
- Evolutionary.circadian sleep models: Sleep’s main purpose is to increase a species’
chances of survival in relation to its environmental demands !
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- Conserving energy!
- Sleep and memory consolidation!
- A gradual process by which the brain transfers information into long-term memory !
Sleep disorders!
- Insomnia: Difficulty in falling asleep, staying asleep or experiencing restful sleep !
- Narcolepsy: Extreme daytime sleepiness and sudden uncontrollable sleep attacks that may
last from less than a minute to an hour !
- When a sleep attack occurs, they may go straight into REM stage !
- May also experiences attacks of cataplexy - a sudden loss of muscle tone often triggered
by excitement and other strong emotions !
- REM-sleep behaviour disorder: The loss of muscle tone that cause normal REM-sleep
paralysis is absent !
- Sleepwalking: Usually occurs during stage 3 or 4 of sleep!
- Often stare blankly and are unresponsive to other people!
- Many seem vaguely conscious of the environment !
- Many have no memory of sleepwalking !
- Nightmares and night terrors: Frightening dreams that arouse the sleeper to a near-panic
state !
- Most common during stages 3 and 4 of sleep!
- Heart rates may double or triple !
- Sleep apnoea: Repeatedly stop and restart breathing during sleep !
- Most commonly caused by an obstruction in the upper airways as muscles lost tone during
sleep !
Why do we dream?!
- Freud’s psychoanalytic theory: Wishful fulfilment!
- The gratification of our unconscious desires and needs !
- Contains manifest content (the surface story) and latent content (It’s disguised
psychological meaning)!
- Cognitive theories: Focus on the process of how we dream and propose that dreaming and
waking thought are produced by the same mental systems in the brain !
- Problem-solving dream models: Dreams are not constrained by reality, they can help us
find creative solutions to our problems and ongoing concerns !
- Activation-synthesis theory: Dreams do not serve any particular function - they are merely
a by-product of REM neural activity!
DRUGS!
- Drugs work by entering the bloodstream and being carried throughout the brain by small blood
vessels called capillaries!
- Capillaries: Contain a blood-brain barrier, a special lining of tightly packed cells that lets vital
nutrients pass through so neurons can function !
- Screens out many foreign substances but some, including various drugs, can pass
through !
- Once drugs are inside, they alter consciousness by facilitating or inhibiting synaptic
transmission!
- Agonist: A drug that increases the activity of a
neurotransmitter!
- They enhance a neuron’s ability to synthesise, store or
release neurotransmitters!
- They bind with and stimulate postsynaptic receptor sites !
- Make deactivation more difficult !
- Types of agonists!
- Opiates!
- Effective pain relievers !
- Opiates have a molecular structure similar to that of
endorphins - they bind to and activate receptor sites and receive endorphins !
- Amphetamines!
- Boost arousal and mood!
- Cause neurons to release greater amounts of dopamine and norepinephrine and by
inhibiting reuptake - therefore dopamine and norepinephrine remain in the synaptic
space longer and keep stimulating postsynaptic neurons!
- Antagonist: A drug that inhibits or decreases the action of a neurotransmitter !
- They reduce a neurons ability to synthesise, store or release neurotransmitters!
- They prevent a neurotransmitter from binding with the postsynaptic neuron !
- Types of antagonists!
- Antipsychotics!
- Treat schizophrenia, who's symptoms are often associated with overactivity of the
dopamine system - so Antipsychotics fit into the dopamine receptor sites but not well
enough to stimulate them !
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Drug tolerance and dependence !
- Tolerance: The decreasing responsively to a drug!
- As it develops, the person must take increasingly larger doses to achieve the same
physical and psychological effects !
- Stems from the body’s attempt to maintain homeostasis —> If a drug changes bodily
functioning in a certain way, the brain tries to restore balance by producing compensatory
responses - reactions opposite to that of the drug !
- Withdrawal: An occurrence of compensatory responses after discontinued drug use !
Environmental stimuli associated with repeated drug use begin to elicit compensatory responses
through classical conditioning!
- If a user takes his or her usual high dose of a drug in a familiar environment, the body’s
compensatory responses are at full strength, but in an unfamiliar environment, the conditioned
compensatory responses are weaker, and the drug has a stronger physiological effect than
normal!
Substance dependence/drug addiction: Maladaptive pattern of substance use that causes a
person significant distress or substantially impairs that person’s life !
- Physiological dependence: If drug tolerance or withdrawal symptoms have developed!
- Psychological dependence: Describes situations in which people strongly crave a drug because
of its pleasurable effects, even if they are not physiologically dependent !
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Misconception about substance dependence: People mistakenly believe that if a drug doesn’t
produce tolerance or withdrawal, one can’t become dependent on it!
- However, people can become dependent on drugs that only produce mild withdrawal due to
it’s pleasurable effects!
- Drug users who often quit and make it through withdrawal eventually start using it again, even
though they are no longer physiologically dependent !
- Genetic predispositions, religious beliefs, family and peer influences and cultural norms may
also influence it!
Depressants: Decrease nervous system activity !
- Reduce tension and anxiety and produce euphoria !
- Tolerance develops gradually and can lead to physiological dependence !
- Alcohol dampens the nervous system by increasing the activity of the brain’s main inhibitory
neurotransmitter, GABA and by decreasing the activity of a major excitatory neurotransmitter,
glutamate!
- There is initially a subjective high as alcohol boosts the activity of several neurotransmitters,
such as dopamine, that produce feelings of pleasure and euphoria !
- After higher doses however the brain’s control centres become increasingly disrupted,
thinking and physical coordination become disorganised and fatigue may occur as BAC rises !
- Blood alcohol content (BAC): A measure of the alcohol concentration in the body!
- Elevated BAC impairs reaction time, coordination and decision making !
- Alcohol myopia: Shortsighted thinking caused by the inability to pay attention to as much
information as when sober !
- People who drink start to focus only on aspects of the situation that stand out - don’t think
about long-term consequences !
- Barbiturates and tranquillisers depress the nervous system by increasing the activity of the
inhibitory neurotransmitter GABA
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- Stimulants: Increase neural firing and arose the nervous system!
- Increase blood pressure, respiration, heart rate and overall alertness !
- Can elevate mood to the point of euphoria but can also heighten irritability !
- Amphetamines reduce appetite and fatigue, reduce the need for sleep and reduce
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depression !
- They increase dopamine and norepinephrine activity !
- Tolerance develops over time !
Cocaine produces excitation, a sense of increased muscular strength and euphoria!
- It increases the activity of norepinephrine and dopamine by blocking their reuptake !
- In large doses it can produce vomiting, convulsions and paranoid delusions !
Ecstasy produces feelings of pleasure, empathy, warmth and elation!
- It increases serotonin functioning, which boosts one’s mood but may cause agitation!
- After it wears off, users feel sluggish and depressed !
- Continued use is associated with impaired memory and sleep difficulties !
Opiates - drugs derived from the opium poppy e.g. morphine, opium and heroin !
- Provide pain relief and cause mood changes by stimulating receptors normally activated by
endorphins, producing pain relief !
- Also increase dopamine activity !
- High doses may lead to a coma and overdoses may cause death!
Hallucinogens powerful mind-altering drugs that produce hallucinations!
- Distort sensory experience and can blue the boundaries between reality and fantasy !
- May experience violent outbursts, paranoia and panic!
- The mental effects of hallucinogens are unpredictable !
- LSD: A powerful hallucinogen that causes a flooding of excitation in the nervous system !
Marijuana slows down neural activity and produces relaxing effects due to the THC in the
marijuana !
- THC also increases dopamine activity !
- Marijuana smoke contains more cancer-causing substances than tobacco smoke!
- High doses may results in negative changes in mood sensory distortions and feelings of
panic and anxiety !
- Can impair reaction time, thinking, memory, learning and driving skill!
- Repeated use produces tolerance - sudden stopping after high doses may result in
vomiting, irritability and disrupted sleep!
Environmental factors !
- The setting in which a drug is taken can influence a user’s reaction !
- Being in a familiar drug-use setting can trigger compensatory physiological responses and
cravings !
- Cultural learning also affects how people respond to a drug !
- Expectations of society!
- What the user expects from using the drug!
HYPNOSIS!
- Hypnosis: A procedure in which the subject is guided by the hypnotist to respond to suggestions
for changes in subjective experience, alterations in perception, sensation, emotion, thought or
behaviour !
- Used in aiding in conducting therapy !
- Hypnotic induction: A process that creates a context for hypnosis - e.g. gazing at an object on
the wall!
- People cannot be hypnotised against their will !
- Hypnotic susceptibility scales: A series of pass-fail suggestions that are read to a subject after a
hypnotic induction !
- Hypnosis does not involve a unique power to get people to behave against their will!
- Hypnosis often increases pain tolerance !
- Social-cognitive theories: Experiences result from expectations of people who are motivated
to take on the role of being hypnotised
!
MOTIVATION AND EMOTION!
- Motivation: A process that influences the direction, persistence and vigour of goal-directed
behaviour!
!
Perspectives on motivation!
- Instinct: An inherited characteristic, common to all members of a species, that automatically
produces a particular response to a stimulus
!
- Homeostasis: A state of internal physiological equilibrium that the body strives to maintain !
- Drive theory of motivation: Physiological disruptions to homeostasis produce drives that motivate
an organism to behave in a way that reduces the tension
!
- Behavioural activation system (BAS): Rouse to action by signals of potential reward and positive
need gratification !
- Activity in this system causes the person to begin or to increase movement toward positive
goals in anticipation of pleasure !
- Produces emotions of hope, elation and happiness!
- Behavioural inhibition system (BIS): Responds to stimuli that signal potential pain, nonreinforcement and punishment!
- Produces fear, inhibition of behaviour, as well as escape and avoidance behaviours !
- Links avoidance motives with negative emotions, such as fear, depression and guilt
!
- Incentives: Environmental stimuli that pull an organism toward a goal !
- e.g. Anticipating a good grade can be an incentive for studying !
- Expectancy x value theory: Goal-directed behaviour is determined by the strength of the
person’s expectation that they will achieve that goal through their behaviours and by the
incentive value the individual places on that goal !
- Motivation = expectancy x incentive value !
- Extrinsic motivation: Performing an activity to obtain an external reward or avoid punishment!
- Intrinsic motivation: Performing an activity for its own sake - because you find it enjoyable or
challenging
!
- Psychodynamic views of motivation!
- Freud: Energy from unconscious motives - especially sexual and aggressive instincts - is
often disguised and expressed through socially acceptable behaviours!
- Modern: Along with conscious mental processes, unconscious motives guide how we act and
!-
feel !
Need hierarchy: We satisfy the needs at the bottom of the triangle before those at the top!
- Self-actualisation: Represents the need to
fulfil our potential - ultimate human motive !
- Motivates us to perfect ourselves mentally,
artistically, emotionally and socially !
- Self-transcendence: Moving beyond a focus
on self to commit themselves to the welfare of
others, to spiritual fulfilment and to cause
higher than themselves
!
- Self-determination theory: Focuses on three
fundamental psychological needs - competence,
autonomy and relatedness - and how these relate
to intrinsic and extrinsic motivation !
- Competence motivation: A basic human need to
experience oneself as capable, to master new
challenges and to perfect skills !
- Autonomy: When people experience their actions
as a result of free choice without external interference !
- Relatedness: Refers to our desire to form meaningful bonds with others !
- Amotivation: An absence of either extrinsic or intrinsic motivation - the behaviour has no real
!
motivational purpose and people either discontinue the behaviour or continue it out of pure
routine !
- External regulation: Behaviour is under the external control of rewards, punishment or
deadlines imposed by others!
- Introjected regulation: Internalisation of the reason for doing the behaviour has occurred e.g. the student may study because she has internalised from her parents that she should do
so!
- Identified regulation: Behaviour is done out of choice !
- Internal regulation: Behaviour is done for its own sake because it brings enjoyment, selffulfilment and stimulation!
HUNGER AND WEIGHT REGULATION
Physiology of hunger!
- Metabolism: The body’s rate of energy utilisation !
- Homeostatic mechanisms are designed to prevent us from running low on energy in the first
place !
- A set point: A biologically determined standard around which body weight is regulated !
- Thus if we overeat or under-eat, homeostatic mechanisms alter our energy utilisation and
hunger to return us close to our original weight !
!
Signals that start and terminate a meal!
- Hunger does not depend on the stomach at all !
- When you eat, digestive enzymes break food down into key nutrients e.g. glucose - a simply
sugar that is the body’s main source of fuel !
- After a meal, some glucose is transported to cells to provide energy while a large portion is
transferred to the liver and fat cells, where it is converted to other nutrients and stored !
- Sensors in the hypothalamus and liver monitor blood-glucose concentrations !
- When they decrease, the liver converts stored nutrients back into glucose !
- Changes in the supply of glucose available to cells provide a signal that helps the brain
regulate hunger !
- Stomach and intestinal distention are satiety signals!
- The walls of these organs stretch as food fills them up, sending nerve signals to the brain !
- This does not mean that your stomach has to be full for you to feel satiated !
- Cholecystokinin (CCK): Is a peptide that helps produce satiety !
- It is released into the bloodstream by the small intestine as food arrives from the stomach !
- These peptides travel to the brain and stimulate receptors in several regions that decrease
food intake
!
Signals that regulate general appetite and weight!
- Leptin: A hormone secreted by fat cells!
- It enters the bloodstream and reaches the brain, where it decreases appetite and increases
energy expenditure !
- It doesn’t make us feel full like CCK and other satiety signals but may influence appetite by
increasing the potency of these signals !
- As we gain fat, we secrete more leptin - We may eat less because satiety factors mae us feel
full sooner !
- As we lose fat and secrete less leptin - it may take a greater accumulation of satiety signals
and thus more food to make us feel full !
- Tend to fall more quickly when we lose weight than the rate it rises when we gain fat !
- The ob gene mutation results in a lack of leptin causing the subject to overeat !
- The db gene mutation results in the brain receptors being insensitive to leptin - they can’t
detect it and become me obese !
!
Brain mechanisms!
- Lateral hypothalamus (side areas): Stimulation of this area causes the want to eat !
- Damage to this area causes the want to stop eating - they also develop trouble swallowing
and digesting and become generally unresponsive to external stimuli !
- Ventromedial hypothalamus (lower-middle area): Stimulating this area causes the want to stop
eating !
- Paraventricular nucleus (PVN): A cluster of neurons packed with receptor sites for various
transmitters that stimulate or reduce appetite !
- Integrates several short-term and long-term signals that influence metabolic and digestive
processes !
!
Psychological aspects of hunger !
- Eating is positively reinforced by the good taste of food and negatively reinforced by hunger
reduction !
- Our expectation that eating will be pleasurable becomes an important motivator to seek and
consume food!
- Food availability is the most obvious environmental regulator of eating!
- Food taste and variety also regulate eating !
- Through classical conditioning, we learn to associate the smell and sight of food with its faste 0
these food cues can trigger hunger !
!
Eating disorders!
- Anorexia nervosa: An intense fear or being fat and severely restrict their for intake to the point of
self-starvation!
- Causes menstruation to stop!
- Produces bone loss!
- Stresses the heart!
- Increases the risk of death!
- Are normally people who are perfectionists !
- Bulimia nervosa: Afraid of becoming fat, binge-eating then purging the food !
- Results in gastric problems and badly eroded teeth !
- Are normally people who tend to be depressed and anxious, exhibit low impulse control and
seem to lack a stable sense of personal identity !
!
SEXUAL MOTIVATION!
- Four-stage sexual response cycle: Excitement, plateau, orgasm and resolution !
- Excitement: Arousal builds rapidly !
- Blood flow increases to arteries in and around the genital organs, nipples and women’s
breasts —> Causes these areas to sweet !
- The penis and clitoris become erect and the vagina becomes lubricated!
- Plateau: Arousal continues to build until there is enough muscle tension to trigger an orgasm!
- Orgasm!
- In males: Contractions of internal organs and muscle tissue surrounding the urethra project
semen out of the penis!
- In females: Rhythmic contractions of the outer third of the vagina !
- Resolution!
- Physiological arousal decreases rapidly and te genital organs return to their normal
condition !
- Males enter a refractory period, where they are temporarily unable to produce another
orgasm !
!
Sex hormones!
- The hypothalamus plays a key role in sexual motivation!
- It controls the pituitary gland, which regulates the secretion of hormones called gonadotropins
into the blood!
- These affect the rate at which the gonads secret androgens, testosterone/oestrogen !
- Sex hormones have organisation effects that direct the development of male and female sex
characteristics!
- Sex hormones have activation effects that stimulate sexual desire and behaviour !
!
The psychology of sex!
- Sexual fantasy can trigger genital erection and orgasm - can enhance arousal !
- Psychological factors ca trigger sexual arousal but also inhibit it!
- ‘Turned off’!
- Sexual dysfunction: Chronic, impaired sexual functioning that distresses a person !
- The psychological meaning of sex depends on cultural contexts !
- Environmental stimuli are pervasive and dependable elicitors of sexual desire and behaviour
e.g. Pornography!
!
Sexual orientation!
- Definition: One’s emotional and erotic preference for partners of a particular sex !
- Homosexual men and women felt that they were somehow different form their same-sex peers
and were more likely to engage in gender-non-conforming behaviours!
- The closer the genetic relatedness, the higher the concordance rates for sexual orientation!
!
SOCIAL MOTIVATION!
- Social relationships insulate us from stressors in our lives !
- They help us obviation positive stimulation!
- They provide us with emotional support!
- They give us attention!
- They permit social comparison - Comparing our beliefs, feelings and behaviours with those of
there people !
- Helps us determine what is normal and helps us judge the level of our cognitive and physical
abilities !
- Situational factors influence our tendency to affiliate - e.g. Fear-inducing situations increase our
desire to be with others !
- We seem to desire most strongly to be with others who have already been through the same or
similar situations !
!
Achievement motivation!
- Need for achievement: A positive desire to accomplish tasks and compete successfully with
standards of excellence !
- Can be driven by a motive for success and/or a fear of failure !
- High-need achievers: People high in achievement and low in fear of failure !
- Tend to strive harder for success when they perceive themselves as personally responsible
for the outcome !
- Achievement goal theory: Focuses on the manner in which success is defined both by the
individuals and within the achievement situation itself !
- Mastery orientation: Focuses on personal improvement, giving maximum effort and perfecting
new skills!
- Ego orientation: The goal is to outperform others!
- Motivational climate: Encourages or rewards either a mastery approach or an ego approach to
defining success!
!
Motivational conflict!
- Approach-approach conflict: Occurs when we face two attractive alternatives and selecting one
means losing the other!
- Avoidance-avoidance conflict: Occurs when we must choose between two undesirable
alternatives!
- Approach-avoidance conflict: Being attracted to and repelled by the same goal !
!
!
EMOTION !
- Definition: Feeling states that involve a pattern of cognitive, physiological and behavioural
reactions to events !
- Are an important form of social communication - provides clues about our internal states and
intentions - influences how other people behave towards us!
- Have important adaptive functions - they help us form intimate relationships and broaden our
thinking and behaviour !
!
The nature of emotions!
- Emotions are triggered by external or internal eliciting stimuli!
- Emotional responses result from our appraisal of these stimuli - gives the situation its meaning
and significance!
- Our bodies respond physiologically to our appraisals!
- Emotions include behaviour tendencies!
- Expressive behaviours: smiling when happy!
- Instrumental behaviours - ways of doing something about the stimulus that evoked the
emotion: Fighting back in self defence !
- Eliciting stimuli: Stimuli that trigger cognitive appraisals and emotional responses !
- Biological factors help determine which stimuli have the greatest potential to arouse emotions !
- Learning influences our emotions !
- Previous experiences can turn certain people or situations into eliciting stimuli !
- Cognitive appraisals: Interpretations and meanings that we attach to sensory stimuli !
- Explains how different people can have different emotional reactions to the same object,
situation or person !
!
The physiological component!
- Emotions involve important interactions between several brain areas, including the limbic system
and the cerebral cortex !
- The cerebral cortex has many connections with the hypothalamus, amygdala and other limbic
system structures !
- Cognitive appraisal processes involve the cortex, where the mechanisms for language and
complex thought reside !
- The ability to regulate emotion depends a lot on the executive functions of the prefrontal cortex !
- When the thalamus receives input from the senses, it can send messages along a ‘high road’,
that travels up to the cortex, and a ‘low road’ travelling directly to the nearby amygdala!
- The low road enables the amygdala to receive direct input from the senses and generate
emotional responses before the cerebral cortex has time to interpret what is causing the
reactions !
- Enables the organism to react with great speed before the cerebral cortex responds with a
more carefully processed cognitive interpretation of the situation !
- The amygdala also functions as an early-warning system for threatening social stimuli !
- The amygdala also reacts to stimuli that evoke strong positive emotions !
- Brain activity is also involved in the regulation of emotional behaviour !
- The prefrontal cortex is the seat of executive functions involving reasoning, decision-making
and control of impulsivity !
- The right hemisphere of the brain controls negative emotions while the left side of the brain
controls positive emotions !
!-
Cultural display rules: Dictate when and how particular emotions are to be expressed!
- Certain gestures, body posturers and physical movements can convey vastly different
meanings in different cultures !
- Instrumental behaviours: Directed at achieving some emotion-relevant goal !
- The more complex a task is, the lower the optimal arousal level !
!
Theories of emotion!
- James-lange somatic theory: Our bodily reactions determine the subjective emotion we
experience !
- We know we feel a certain way because our body’s reactions tell us so !
- Cannon-bard theory: The subjective experience of emotion and physiological arousal does not
cause on a mother but instead are independent responses to an emotion-arousing situation !
- Facial muscles involved in emotional displays feed messages to the brain!
- Facial feedback hypothesis: Feedback from the facial muscles to the brain plays a key role in
determining the nature and intensity of emotions that we experience !
- Cognitive-affective theories: Examine how cognitions and physiological responses interact !
- Two-factor theory of emotion: The intensity of physiological arousal tells us how strongly we
are feeling something, but situational cues give us the information we need to label the
arousal and tell ourselves what we are feeling