MBB1 - Learning and Memory

Learning

set of biological, cognitive and social processes through which organisms make meaning from their experiences, producing long lasting changes in their behavioir, abilities and knowledge

Sensitisation

temporary state of heightened attention and responsitivity that accompanies sudden and surprising events. The learner remains alert to potentially threatening stimuli in the enviro and has an increased response to subsequent stimuli

Habituation

the gradual diminishing of attention and responsivity that occurs when a stimulus persists.

Classical conditioning

learning a predictive relationships between a neutral stimulus and a unconditioned stimulus that naturally cause a unconditioned resposne, so that the previously neutral stimulus becomes a conditioned stimulus that produces a conditioned response

Phases Of Classical conditioning

prior to conditioning - 1a - UCS+UCR

1b - NS+No UCR

during conditioning - 2 - NS+UCS=UCR

After conditioning - 3 -CS=CR

stimulus generalization

the tendency to respond to a stimulus that is only similar to the original conditioned stimulus with the conditioned response

extinction

the diminishing of a conditioned response; occurs in classical conditioning when an unconditioned stimulus (US) does not follow a conditioned stimulus (CS); occurs in operant conditioning when a response is no longer reinforced.

discrimination

in classical conditioning, the learned ability to distinguish between a conditioned stimulus and stimuli that do not signal an unconditioned stimulus

spontaneous recovery

the reappearance, after a pause, of an extinguished conditioned response. spaced over multiple sessions wll gradually prevent spontaneous recovery

rapid reacquisition

Learning in a second acquisition phase that follows extinction that occurs more quickly than in the initial acquisition phase.

operant conditioning

Relationship between stimuli and behavioural responses (voluntary) and events that follow (how consequences of behaviour shape future behaviour). Behaviour is shaped by the learner's history of experiencing rewards and punishments for their actions

positive reinforcement

learn to reproduce a behaviour if the consequence is receiving something pleasant

negative reinforcement

learn to reproduce a behaviour if the consequence is something unpleasant will stop

continuous reinforcement

rarely occurs naturally, leads to rapid extinction once the reinforcer is withheld

partial reinforcement

leads to more persistent learning because the learner becomes accustomed to reinforcement occurring on some occasions and not others. Not every behaviour gets rewarded, but worth doing it as some will be.

extinction burst

an increase in the frequency of responding when an extinction procedure is initially implemented.

shaping complex behaviour

reinforces successive approximations to the desired behaviour

1.Start by reinforcing a high frequency component of a desired response

2.Then drop this reinforcement - bheaviour becomes more variable again

3.Await a response that is still closer o the desired response then reintroduce reinforcer

4.Keep cycling through as closer and closer approximations to the desired behaviour are achieved

5.Enables a molding of a response that is not normally part of animals repertoire

punishment

a behaviour is punished (weakened) whenever the learner experiences an undesirable consequence for that behaviour

positive punishment

stop producing behaviour if consequence is the presentation of an unpleasant stimulus

negative punishment

stop producing a behaviour if the consequence is that something desiable is taken away.

punishment is effective

Contingency - the relationhsip between the behaviours and the punishment must be clear

Contiguity - the punisher must follow the behaviour swiftly

Consistency - the punisher needs occur for every occur

drawbacks to punishment

rarely works for long-term behaviour change

Doesnt teach more desirable behaviour

Brings more attention to behaviour

Threat of punishment removed behaviour returns

Produces negative feelings in the learner, dont promote new learning

Harsh punishment may teach learner to use such behaviour towards others (social learning)

alternatives to punishment

stop reinforcing the problem behaviour (extinction)

Reinforce alternative behaviour

Stimuli in enviro can become antecedents for operantly conditioned behaviours

antecedent

cue that signals the availability of a reinfrcer (eg, red light in rat box)

Antecedent-reinforcer relationship is based on a classically conditioned associatio

reinforcer

any consequence of a behaviour that makes that behaviour more likely to recur in the future

Little Albert Study

Watson and Rayner (1920). Example of classical conditioned emotional response in humans

1. Rat, horrible sound, 2 instances in initial session

2. Another 5 instances a week later

3. Sufficient to produce fear response to rat alone

4. Generalisation occurred to other furry animals and santas white beard

5. Albert removed before extinction could occur

B.F. Skinner and Operant Conditioning

-created the Skinner Box, which is a conditioned environment for studying conditioning

-(rat experiment with button that gave food and button that shocked=>at first rats pressed each button randomly, then followed conditioning

Pavlov's dog

Each time the dog was fed, a bell was rung for a few seconds and the amount of saliva produced was measured. Then the bell was rung and no food was given. He discovered that the amount of saliva produced on this trial was the same as when the food was given.

cognitive map

mental representation of the spatial characteristics of a familiar environment

Tolman and Latent Learning

Rats ran around a maze for 10 days, given food on the 11th, run fast on the 12th when they learn food is at the end.

challenged the traditional behaviorist account with another classic experiment in which he demonstrated that learning could occur in the absence of rewards and punishments.

Latent learning

learning that occurs but is not apparent until there is an incentive to demonstrate it

social-cognitive learning theory

the theory that people learn social behavior in large part through observation and imitation of others and by cognitive processes such as plans, expectations, and beliefs

Bandura modelling aggression

1. Bandura had children watch on a screen as modle was agrressive towards doll

2. Some children watched as the model experienced poisitive reinforcement afterwards

3. others watched as positive punishment occurred

4. others saw no consequences

5. results - Demonstrated vicarious reinforcement and vicarious punishment.

That learning can occur social through observation, in the absence of directly experienced consequences

Performance of aggressive acts is influenced by mental representaations of observed consequences

Knowledge remained latent in the model punished group until a reward was introduced

memory

A set of storage systems and processes for encoding, storing and retrieving information acquired through our sense and for relating this info to previously acquired knowledge.

A mental represntation of knowledge within memory systems stored within neural networks of the brain.

Atkinson and Shiffrin

Information Processing Model -- to encode, store and retrieve

encoding

The processes involved in attending to acquiring info from experiences and mental processes:

Registration of info in sensory regions of brain

Attention to elements of an experience

Interpretation and integration of experience with prior knowledge

storage

Encoding produces representations of info that are consolidated in memory traces in networks of neurons throughout the brain

Different kinds of memories are stored in different networks.

Storage capacity and duration differ between the different memory systems.

retrieval

Everything from personal reminiscence of past experiences, recalling facts, executing practiced motor skills to conditioned responses.

Explicit and implicit retrieval processes

A reconstructive and sometimes error-prone process that changes the memory trace through 'reconsolidation' after retrieval (misinformation effect).

sensory memory

A temporary, sensory based representation of input received through sensory channels

Provides a buffer between early sensory processes and later cognitive processes.

Only some of the info stored in sensory memory will be retained

Iconic (visual) and echoic (auditory) memory

Brief duration (decays quickly)

Large capacity (relative to STM)

George Sperling

Tested recall time by flashing rows of numbers and saw if participants could immediately recall the numbers

Full report->

Sperling found that participants could name only 4 of the letters on average

They reported feeling like they briefly had access to a visual image of the entire display, but that it faded more quickly than they had time to read the letters

It was as if the info was being read from a rapidly decaying icon

Partial report->

Array flashed for 50msecs

Auditory tone indicates line to be remembered

Subject repeats cued line

Capacity estimation increased from 4-12

full report method underestimated the capacity of the iconic trace by conforunding the reporting method with the duration of the iconic trace

short term memory

conscious representation of the present moment

The temporary store in which we integrate current sensory experience with long term memory to achieve current goals.

Capacity - limited

Duration 18-30secs

measuring verbal LTM capacity

Assessed using digit span task

Immediate serial recall of verbally presented digits in the order they were presented

The length of sequence is increased by one item after each successful attempt to determine the upper limit or span

A participants span is reached when they fail on two trials at a given series length

So if you were unable to recall both trials for a series of 8 items, then your digit span will be 7 items

Average adult span is 7 +- 2 items.

duration of stm

The brown-peterson task

Recall the names of 3 consonants

Memory probed at 3 second retention intervals

To prevent rehearsal, participants were required to count backwards from a given number in 3s until told to stop

Forgetting due to trace decay or interference from previous trials?

maintenance rehearsal and transfer to LTM

Verbal rehearsal keeps info active in stm and strengthens the trace to increase the chance it will be stored in LTM

Serial position effect

Immediate free recall of lists of numbers or words is affected by the position of items in the studied list

primacy effect

Primacy effect provides evidence for transfer to long-term memory for items that receive more rehearsal

Primacy effects are eliminated if rehearsal is prevented by introducing a concurrent task

recency effect

Recency effect reflects availability of info still in short term memory

Recency effect is reduced by introducing a filled retention interval before recall

Levels of processing

The purpose of STM is to encode information meaningfully

Meaningful processing of info during encoding will produce long-term memory traces

Shallow processing is less effective for long-term retention

Craik and Tulving (1975) test this hypothesis with their studo of levels of processing

Test the idea that LTM for words is influenced by the depth of the encoding process used in STM

Working memory

a newer understanding of short-term memory that focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory

phonological loop

A mental workspace for manipulatign auditory and verbal info

Digit span backwards is considered a test of phonological/verbal working memory because you must actively manipulate the info in memory, rather than just maintain the sentence

Important in language development and verbal reasoning tasks

visuo-spatial sketch-pad

A temporary store for representation of visual and spatial info such as faces, objects written words and cognitive maps

Enables the mental manipulation of visually and spatially represented info

Mental rotation of objects

Visual and spatial mnemonics

Mental arithmetic

Cognitive maps for navigation

central executive

Executive processes are used in planning and coordinating complex behaviour - goal orientation, focus attention, control of social behaviour, switching between tasks, planning and problem solving

Executive processes are governed by circuitry in the pre-frontal cortex, especially dorsalateral prefrontal cortex and the anterior cingulate cortex

Neural basis of working memory

Executive process are based within networks in the pre-frontal cortex

Phonological loop is a left hemisphere fronto-temporal love network

Visuo spatial sketchpad is a right occipital parietal network

The episodic buffer integrates multi-modal info in an integrated episodic trace within the parietal cortex

declarative memory

knowing what, why, where and when"

Facts, events, locations, autobiographical knowledge

Reminiscence of personally experienced events

Hippocampal-dependent

non-declarative memory

"knowing how"

Motor skills

Cognitive skills

Non-hippocampal dependent

episodic memory

sub-division of declarative memory

vivid first-person recall of personally experienced events

when/where memories

Contextualised memory

Mental time travel

semantic memory

general knowledfe of facts about the world and yourself

what/why memories

Abstract knowledge (including abstract self-knowledge)

procedural memory

subdivision of non-declarative memory

learning and performance of motor and cognitive skills

priming

subdivision of non-declarative memory

demonstrated by a change in the ability to identify a stimulus as the result of prior exposure to that stimulus, or a related stimulus

Repetition priming -> eg. prior to expose to a word in a lexical decision task will make that word easier to respond to ifit is repeated in the task

associative/semantic priming -> eg. the prior presentation of the word "nure" facilitates subsequent identification of the word "doctor"

other subdivisions of non-declarative memory

Classical conditioning

Operant conditioning

Non-associative learning

Amnesias

Deficits in memory caused by brain damage, disease, drug abus and psychological trauma

Selective deficits in memory processes seen in cases of amnesia provide support for the proposed division between the declarative and non-declarative memory systems

retrograde amnesia

an inability to remember knowledge acquired before the brain injury

Usually temporally graded (amnesia worse the closer to the event)

anterograde amnesia

an inability to recall anything since the time of the brain injury

Inability to learn new info

dissociation of declarative and non-declarative memory

Anterograde amnesiacs are capable of new procedural learning

Despite stating that they have neverperformed the task before, they showan improvement over time.• This demonstrates that procedurallearning can proceed independently ofthe brain systems required fordeclarative memories.

Preserved non-declarative memory in anterograde amnesia

Further studies show that patients with anterograde amnesia show other types of preserved non-declarative memories

Intact classical and operant conditioning

Intact priming effects

Normal habituation and sensitisation