Learning & Memory

Learning and Memory

Definition and nature of learningTypes of learning

Pavlov’s Classical Conditioning Skinner’s Operant/ Instrumental

Conditioning Bandura’s Social Learning Theory

Memory and forgetting

Learning Learning

relatively permanent change in an organism’s behavior due to experience

What is learning?

Some learning involves development of new skills.

I am learning how to ride a bike.Some learning involves changes in existing behavior.

She’s learning to control her temper.Some learning involves simple associations.

I finally learned that where there is smoke, there is fire.

What is learning?

And sometimes it involves learning complex belief systems.

He is trying to learn the Buddhists view of life.

We also figure things out for ourselves.Learning a mathematical formula.

Learning can also be imposed on us by circumstance.

If you touch a hot stove, you’ll burn your hand.

Learning Theory

What mechanisms are responsible for the complexity of learning? Locke (1600s) and Berkeley (early1700s)

AssociationistsWe learn by associating one idea with

another•The word “flower” with the smell and

sight of a flower•The word “stove” with the sensation of

heatMore complex learning more associations

AssociationLearning to

associate two events

learning that two events occur together

two stimulia response and

its consequences

Event 1 Event 2

Sea snail associates splash with a tail shock

Seal learns to expect a snack for its showy antics

Animals vs. Human

Study of animals: reveals same principles of learning that apply to humansHow does a dog learn to sit on command?

Look Bruce, Look Bruce, when I said when I said

SIT...SIT...

Habituation

One of the simplest forms of learningIt means; decline in response of

organism’s response to stimulus once that stimulus becomes familiar; simply getting used to...

However, organism does not learn anything new from that event

Habituation

A common way occurs in which a person’s attention is captured by a loud or sudden stimulus. For example, a person who moves to a house on a busy street may initially be distracted every time a loud vehicle drives by. After living in the house for some time, however, the person will no longer be distracted by the street noise—the person becomes habituated to it and the initial response disappears.

Habituation

Our environments are full of sights and sounds

Habituation allows us to ignore repetitive, unimportant stimuli.

Habituation occurs in nearly all organisms, from human beings to animals

Learning in Animals

There are three major areas of learning:

Habituation

Classical Conditioning (by Pavlov)

Instrumental (Operant) Conditioning (by Skinner)

Classical or Pavlovian Conditioning

We learn to associate two stimuli

Two related events:

Lightning

Stimulus 1

Thunder

Stimulus 2

Result after repetition

We see lightning

Stimulus

We wince anticipatingthunder

Response

Operant Conditioning

We learn to associate a response and its consequence

Response: Pushingvending machine button

Consequence:Receivinga candy bar

Learning

Behaviorism Promoted by John B. Watson View that psychology…

should be an objective sciencestudies behavior without reference to mental processes

Classical or Pavlovian Conditioning

Ivan Pavlov 1849-1936 Russian physician/

neurophysiologist Nobel Prize in 1904 studied digestive

secretions

Classical or Pavlovian Conditioning

Classical Conditioning organism comes to associate two stimuli

lightning and thundertone and food

begins with a reflex a neutral stimulus is paired with a

stimulus that evokes the reflex neutral stimulus eventually comes to

evoke the reflex

Classical or Pavlovian Conditioning

Pavlov’s device for recording salivation

Classical or Pavlovian Conditioning

Unconditioned Stimulus (UCS) effective stimulus that unconditionally-

naturally and automatically - triggers a response

Unconditioned Response (UCR) unlearned, naturally occurring response

to the unconditioned stimulussalivation when food is in the mouth

Classical or Pavlovian Conditioning

Conditioned Stimulus (CS) originally neutral stimulus that, after

association with an unconditioned stimulus, comes to trigger a conditioned response

Conditioned Response (CR) learned response to a previously neutral

conditioned stimulus

Pavlov’s Classic Experiment

Before Conditioning

During Conditioning After Conditioning

UCS (foodin mouth)

Neutralstimulus(tone)

Nosalivation

UCR (salivation)

Neutralstimulus(tone)

UCS (foodin mouth)

UCR(salivation)

CS(tone)

CR (salivation)

Classical or Pavlovian Conditioning

Acquisition the initial stage of learning, during which

a response is established and gradually strengthened

the phase associating a neutral stimulus with an unconditioned stimulus so that the neutral stimulus comes to evoke a conditioned response

Classical or Pavlovian Conditioning

Extinction diminishing of a conditioned

response in classical conditioning, when

an unconditioned stimulus does not follow a conditioned stimulus

Classical or Pavlovian Conditioning

Spontaneous recovery reappearance, after a rest period, of

an extinguished conditioned responseGeneralization

tendency, once a response has been established, for stimuli similar to the conditioned stimulus to evoke similar responses

Classical or Pavlovian Conditioning

Discrimination in classical conditioning, the

ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus

Nausea Conditioning among Cancer Patients

UCS(drug)

UCR(nausea)

CS(waiting room)

CS(waitingroom) CR

(nausea)

UCS(drug)

UCR(nausea)

Little Albert’s Fear Conditioning

UCS(loud noise)

UCR(fear)

CS(rat)

CS(rat)

CR(fear)

UCS(loud noise)

UCR(fear)

Stimulus similarto rat (such as rabbit)

Conditioned fear(generalization)

Operant Conditioning

Operant Conditioning type of learning in which behavior is

strengthened if followed by reinforcement or diminished if followed by punishment

Law of Effect Thorndike’s principle that rewarded

behavior is likely to recur

Operant Conditioning

Operant Behavior complex or voluntary behaviors

push button, perform complex task

operates (acts) on environment produces consequences

Respondent Behavior occurs as an automatic response to

some stimulus

Operant Conditioning

B.F. Skinner (1904-1990) elaborated

Thorndike’s Law of Effect

developed behavioral technology

Operant Conditioning

Operant Chamber (“Skinner Box”) soundproof chamber

with a bar or key that an animal can manipulate to obtain a food or water reinforcer

contains a device to record responses

Operant Conditioning

Reinforcer any event that strengthens the

behavior it followsShaping

operant conditioning procedure in which reinforcers guide behavior toward closer approximations of a desired goal

Principles of Reinforcement

Primary Reinforcer an innate reinforcer satisfies a biological need

Secondary Reinforcer a conditioned reinforcer an event that gains its reinforcing

power through its association with a primary reinforcer

Schedules of ReinforcementContinuous Reinforcement

reinforcing the desired response each time it occurs

learning occurs rapidly extinction occurs rapidly

Partial Reinforcement reinforcing a response only part of the time results in slower acquisition greater resistance to extinction

Schedules of Reinforcement

Fixed Ratio (FR) schedule that reinforces a response

only after a specified number of responses

the faster you respond, the more rewards you get

different ratios very high rate of responding like piecework pay

Schedules of Reinforcement

Variable Ratio (VR) schedule that reinforces a

response after an unpredictable number of responses

like gambling, fishing very hard to extinguish because

of unpredictability

Schedules of Reinforcement

Fixed Interval (FI) a schedule that reinforces a

response only after a specified time has elapsed

response occurs more frequently as the anticipated time for reward draws near

Schedules of Reinforcement

Variable Interval (VI) schedule that reinforces a

response at unpredictable time intervals

produces slow, steady responding like pop quiz

Punishment

Punishment aversive event that

decreases the behavior that it follows

powerful controller of unwanted behavior

Problems with Punishment

Punished behavior is not forgotten, it's suppressed--behavior returns when punishment is no longer eminent

Causes increased aggression- shows that aggression is a way to cope with problems-- explains why aggressive delinquents and abusive parents come from abusive homes

Problems with Punishment

Creates fear that can generalize to undesirable behaviors, e.g., fear of school, learned helplessness, depression

Does not necessarily guide toward desired behavior--reinforcement tells you what to do,punishment tells you what not to do-- combination of punishment and reward can be more effective than punishment alone

Punishment teaches how to avoid it

Cognition and Operant Conditioning

Cognitive Map mental representation of the layout of one’s

environment example: after exploring a maze, rats act as

if they have learned a cognitive map of itLatent Learning

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

Operant vs Classical Conditioning

Comparison of Classical and Operant ConditioningClassical Conditioning Operant Conditioning

The response Involuntary, automatic “Voluntary,” operates on environment

Acquisition Associating events; CS announces Associating response with a conse- UCS. quence (reinforcer or punisher).

Extinction CR decreases when CS is repeatedly Responding decreases when reinforce- presented alone. ment stops.

Cognitive Subjects develop expectation that Subjects develop expectation that a processes CS signals the arrival of UCS response will be reinforced or punished;

they also exhibit latent learning, without reinforcement.

Biological Natural predispositions constrain Organisms best learn behavior similar to predispositions stimuli and responses can easily be their natural behaviors; unnatural be- associated. haviors instinctively drift back toward

natural ones.

Observational Learning

Observational Learning learning by observing and imitating the

behavior of othersModeling

process of observing and imitating behavior

Prosocial Behavior positive, constructive, helpful behavior opposite of antisocial behavior