Lecture 4 - Cognition I

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PL1101E: Introduction to Psychology 1

Cognition I

Learning and Memory

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Lecture Outline

What is Cognition?

Learning

Classical Conditioning

Operant Conditioning

Other LearningPhenomena

Memory

Types of Memory

Sensory Memory

Short-term Memory Long-term Memory

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What is Cognition?

From Colman (2001) in the OxfordDictionary of Psychology:

The mental activities involved in acquiring andprocessing information.

Its study includes cognitive psychology,psycholinguistics, artificial intelligence, andcognitive neuropsychology.

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What is Cognition?

Cognitive Psychology is the branch of psychology thatstudies topics such as: Attention

Perception

Learning Memory

Thinking

Problem solving

Decision making

Language

These will be surveyed in greater depth in PL3233Cognitive Psychology.

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Learning

What is learning? Any relatively lasting change

in behaviour resulting fromexperience.

The key points are behaviourand experience.

Contrast with maturationalchange, which is due togenetic dispositions E.g. height, weight, brain size Walking (can only occur once

nervous and muscular systemhas reached some level ofmaturity).

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Classical Conditioning: the association oftwo stimuli in the environment.

Does the mere sight of thegolden arches in front ofMcDonalds makes you feelpangs of hunger and thinkabout hamburgers?

If it does, you are displaying anelementary form of learningcalled classical conditioning.

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Applies to reflexive, involuntary behaviour.

Learning to make a reflex response toanother stimulus that is not the naturalstimulus that would normally invoke thatparticular reflex.

Discovered (by chance) by Ivan Pavlov.

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Important Concepts Stimulus Response

The stimulus refers to any object, event, or experience thatcauses a reaction (response) in the organism.

Unconditioned stimulus (UCS or US)A naturally occurring stimulus that produces the involuntary

response.

Unconditioned means unlearned or naturally occurring.

Unconditioned response (UCR or UR)An involuntary, reflexive reaction to a naturally occurring

stimulus.

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Conditioned stimulus (CS)

Stimulus that is subsequently capable of invoking a learnedreflex response on its own because it has been paired withthe original unconditioned stimulus.

Conditioned means learned.A neutral stimulus can become a conditioned stimulus when

paired with an unconditioned stimulus.

Conditioned response (CR)

Learned reflex reaction to a conditioned stimulus.

Sometimes called a conditioned reflex.

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UCSKiss

UCRRacing Heart

CSSight of

Significant Other

UCSKiss

UCRRacing Heart

CSSight of

Significant Other

CRRacing Heart



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Basic principles and findings

CS must come before UCS.

CS and UCS must follow each other closely in time -ideally, only several seconds apart.

Several to many pairings between the neutralstimulus and the UCS must take place beforeconditioning can occur.

CS is usually some distinctive stimulus that stands outfrom other competing stimuli.

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PL1101E: Introduction to Psychology13


Stimulus generalization

A stimulus that is similar to the original CS can elicit a CR.

Stimulus discrimination

Organisms can learn to be more discriminating if the similarstimulus is never paired with the UCS.

Extinction

When a learned response disappears or is weakened becauseof the removal or absence of the UCS.

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Spontaneous recovery

A learned response canreappear even afterextinction has occurred.

Learning is a relatively

permanent change inbehavior.

Higher-order conditioning

Another neutral stimulus

can become a second CSwhen it is paired with anexisting strong CS.

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Conditioned emotional response (CER) Classical conditioning of emotional responses to learned stimuli, e.g. fear of

dogs or the emotional reaction that occurs when seeing an attractiveperson. CERs may lead to phobias irrational fear responses.

Vicarious conditioning Watching the reactions of other people can induce classical conditioning of a

reflex response or emotion.

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Laws of Learning

Acquisition(conditioned response andunconditioned responsepresented together)

Training CS alone Pause Spontaneous recovery

STRONG

WEAK

Strength

ofConditioned

R

esponse(CR)

TIME



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Laws of Learning

TIME


Extinction (conditioned stimulus by itself)A basic phenomenon of learning that occurswhen a previously conditioned responsedecreases in frequency and eventuallydisappears.Acquisition

STRONG

WEAK

Strength

ofConditioned

R

esponse(CR)



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Laws of Learning

TIME


Spontaneous Recovery

The reemergence of anextinguished conditionedresponse after a period of restand with no furtherconditioning.Acquisition Extinction

Spontaneous recovery ofconditioned response

Extinction follows(conditionedstimulus alone)

STRONG

WEAK

Strength

ofConditioned

R

esponse(CR)



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Term coined by B. F. Skinner.

Applies to voluntary behaviour. Learning through the effects of pleasant and unpleasant

consequences to responses. Learning depends on what happens after the response the

consequence.

Developed from Thorndikes Law of Effect If a response is followed by a pleasurable consequence, it will

tend to be repeated, and if followed by an unpleasantconsequence, it will tend not to be repeated.

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Why is credit card use so insidious? (fromFeinberg, 1986). Hand card over to salesperson (behaviour).

Immediate delivery of desired item (reinforcer pleasant consequence).

Behaviour increases.

Having to pay for your purchases, or rackingup a debt (unpleasant consequence) occursmuch later, and may not be linked to theoriginal behaviour.

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PL1101E: Introduction to Psychology


Differences between classical and operantconditioning

Classical: Behaviour changes are due to the

association of two stimuli (CS-UCS) presented prior tothe response (CR).

Focuses on elicitedbehaviours.

Operant: Behaviour changes as the result of theconsequences that follow it (reinforcement orpunishment).

Focuses on emittedbehaviours.

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Important Concepts Reinforcement

Any event or stimulus, as a consequence of a response, thatincreases the probability that the response will occur again.

Positive reinforcement The reinforcement of a response as a result of the addition or

experiencing of a pleasurable stimulus. E.g. getting an A grade for studying hard.

Negative reinforcement The reinforcement of a response as a result of the removal, escape

from, or avoidance of an unpleasant stimulus. E.g. Taking Panadol is a negative reinforcer it removes your

headache.

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Intended Results

Increase in behaviour(reinforcement)

When stimulus is added, the result is . . .

Positive Reinforcement

Example: Giving a raise for goodperformance.

Results: INCREASE in response of goodperformance.




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Increase in behaviour(reinforcement)

When stimulus is removed, the result is .. .Negative Reinforcement

Example: Applying ointment to relieve itchy rashleads to higher future likelihood of applyingointment.

Results: INCREASE in response of using ointment

Intended Results




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Shaping

Breaking down the desired, complex behaviour into simplerones and reinforcing those simpler steps so as to reach thedesired behaviour.

Successive approximations the small steps in behaviourthat will sequentially lead to a particular goal behavior.

Extinction

Occurs if the behavior (response) is not reinforced.

Generalization, discrimination, and spontaneousrecovery also occur in operant conditioning.

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Reinforcement Schedules

Partial reinforcement effect

If a response is reinforced inconsistently (i.e., some, but notall, correct responses are reinforced), the response will tendto be very resistant to extinction.

Continuous reinforcement

All correct responses are always reinforced.

More easily extinguished.

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Partial Reinforcement Schedules

Ratio (response) based

Fixed ratio - number of responses required forreinforcement is consistent and does not change. E.g. get a stamp for every purchase and when you

collect 10 stamps, your 11th purchase is free!

Variable ratio - number of responses required forreinforcement changes for each trial or event. E.g. Jackpot machines.

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Partial Reinforcement Schedules:

Cum

ulativefrequenc

yof

responses

Time

Fixed-Ratio Schedule:A schedule by whichreinforcement is given onlyafter a specific number ofresponses are made.

Typical Outcome:Short pauses occur after eachresponse. Because the moreresponses, the more

reinforcement, fixed-ratioschedules produce a high rateof responding.

There are shortpauses after each

response.



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Cum

ulativefrequencyof

responses

Time

Variable-Ratio Schedule:A schedule by whichreinforcement occurs after avarying number of responsesrather than after a fixed

number.

Typical Outcome:Responding occurs at a highrate.

Responding occursat a high, steadyrate.



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Interval (time) based

Number of responses does not matter.

Fixed interval - the same amount of time must pass before

reinforcement becomes possible. Response rate tends to increase as the end of the interval

approaches

E.g. cramming for final exam.

Variable interval - the amount of time that must pass beforereinforcement becomes possible is not predictable.

E.g. consistent studying for potential pop quizzes.

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Variable-Interval Schedule:A schedule by which the timebetween reinforcements variesaround some average ratherthan being fixed.

Typical Outcome:Produces a fairly steadystream of responses.

Cum

ulativefrequencyof

responses

Time

Responding occurs

at a steady rate.



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PunishmentAny event or object that follows a response and

makes that response less likely to happen again. Dont confuse with negative reinforcement, which is meant

to increase the likelihood of the response!

Punishment by application Punishing a response with an unpleasant stimulus.

E.g. spanking Punishment by removal

Punishing a response by removing a pleasurable stimulus. E.g. youre grounded!

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Decrease inbehaviour(punishment)

When stimulus is added, the result is . . .

Positive Punishment

Example: Yelling at a teenager forstealing a bracelet.

Results: DECREASE in frequency ofresponse of stealing.

Intended Results




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Decrease inbehaviour(punishment)

When stimulus is removed, the result is .. .Negative Punishment

Example: Teenagers access to car restricted byparents due to teenagers breaking curfew.

Results: DECREASE in response of breaking curfew.

Intended Results




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Illustration of difference between negativereinforcement and punishment byremoval:

Desired behaviour submitting term paperson time:Negative reinforcement hand in paper before

deadline to avoid late penalty.Punishment by removal deduct 10 marks for

each day the paper is late.

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Effective Punishment

Immediacy punishment should immediately follow

the behaviour it is meant to punish.

Consistency punishment should be consistent.

Punishment of the wrong behaviour should be paired,whenever possible, with reinforcement of the rightbehaviour.

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Real-life applicationdealing with naughtychildren (as seen inSupernanny,

previously aired onArts Central):

Punishment time-outs, withdrawal of

privileges. Extinction ignore tantrums so they are not

reinforced.

Positive reinforcement praise, stars, treats.31 Jan 11


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Other Learning Phenomena

Learned helplessnessA history of repeated failures in the past may result in

a tendency for not trying to escape from a situationeven when escape is possible.

Observational learning Learning new behavior by watching that behaviour

being performed by someone else. Learning/performance distinction - referring to the

observation that learning can take place without actualperformance of the learned behavior.

TV violence?

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Memory

What is it?An active system that receives information from the

senses, organizes and alters it as it stores it away,and then retrieves the information from storage.

Three Major Memory Processes Encoding

Conversion of sensory information into a form that is usablein the brains storage systems.

Storage Keeping information for some period of time.

Retrieval Getting stored information into a form that can be used.

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Sensory MemoryThree-stage model of memoryIn this model, memory has three major components:(1) Sensory memory, which briefly holds incoming sensory information.

Sensory memory:+ iconic storage+ echoic storage

Types of Memory



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Types of Memory

Sensory memory

The stage where information first enters the nervous systemthrough the sensory systems the very first stage of memory.

Iconic memoryVisual sensory memory, lasting only a fraction of a second. Large capacity whatever that can be seen at one time.

Eidetic imagery - the rare ability to access a visual memory for 30seconds or more.

Echoic memory The brief memory of something that was just heard. Capacity - limited to what can be heard at any one moment and is

smaller than the capacity of iconic memory Duration lasts longer than iconic about 2 to 4 seconds.

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Short-term Memory:Three-stage model of memory(2) Working (short-term) memory, which processes certain information receivedfrom sensory memory and information retrieved from long-term memory.

Short-term memory: Lasts 12-30 secondsCapacity of 7 +/- 2 chunks of information

Types of Memory



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Types of Memory

Short-term memory (STM) (working memory)

Information is held for brief periods of time while being used. Used for selective attention:

Focusing on only one stimulus or task from among all sensory input.

Capacity magic number 7 (+ or 2). Maintenance rehearsal:

Practice of saying something over and over in ones head in order tomaintain it in STM.

Information in STM tend to be encoded in auditory form.

Duration lasts from about 12 to 30 seconds without rehearsal Susceptible to interference

e.g., if rehearsal is interrupted, have to start over.

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Long-term Memory:Three-stage model of memory(3) Long-term memory, which stores information for longer periods of time.Source: Adapted from Atkinson & Shiffrin, 1968.

Long-term memory:+ Permanent method of

storing memories+ Unlimited capacity

Types of Memory



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Types of Memory

Long-term memory (LTM) Where information is kept more or less permanently.

Information is primarily organized in semantic andconceptual associations.

Types of LTM Nondeclarative (procedural) memory

Memory for skills, procedures, habits, emotional associations,and conditioned responses.

These memories are not conscious (implicit memory) but areimplied to exist because they affect conscious behavior.

Amnesia typically does not affect procedural memory.

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Types of Memory

Declarative memory

Memory containing information that is conscious (explicitmemory) and known.

Semantic memory

Memory for facts. General knowledge, knowledge of language, and

information learned in formal education.

Episodic memory

Memory for events.

Contains personal information not readily available toothers, such as daily activities and occurrences.

Amnesia typically affects declarative memory.

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Long-Term Memory

Semantic Memory(general memory)

Episodic Memory(personal knowledge)

Declarative Memory(factual information) Procedural Memory(skills and habits)



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Long-Term Memory



Procedural Memory(skills and habits)Declarative Memory(factual information)

Example:Yusof Ishakwas the first presidentof Singapore



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Declarative Memory(factual information)

Example:Riding a bicycle

Procedural Memory(skills and habits)

Long-Term Memory



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Long-Term Memory


Example:Yusof Ishak is Malay.






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Example:Remembering your visit to YusofIshak House in NUS




Long-Term Memory



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References

Colman, A. M. (2001). A dictionary ofpsychology. Oxford: Oxford UniversityPress.

Feinberg, R. A. (1986). Credit cards asspending facilitation stimuli: A conditioninginterpretation. Journal of Consumer

Research, 13, 348-356.

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Summary

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Summary

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Summary

3 stages of memory Encoding

Storage

Retrieval

3 types of memory

Sensory (iconic and echoic) Short-term (working)

Long-term (declarative and nondeclarative)

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Take Home Message

Can you remember what you have learnedtoday?

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Lecture 4 - Cognition I

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