Basic Principles of Learning

Basic Principles of Learning

Definition of Learning

• Relative permanent change in behavior brought about through experience or interactions with the environment– Not all changes result from learning

– Change in behavior not always immediate

• Years of isolating and studying behavior produced different principles of learning


Classical Conditioning: Learning by Association

• Ivan Pavlov in Russia– Nobel Prize for saliva in digestion– Reflexive response controlled by arbitrary

stimulus (salivation when attendant approached)

• Association - key element – First recognized by Aristotle– Pavlov: classical conditioning was form of

learning through association


Container of meat powder

Observation screen

Revolving drum for recording responses

Device to count drops of saliva

Tube for collection of saliva

Pavlov’s Experiment

Test of conditioning: after classical conditioning, the neutral stimulus becomes a conditioned stimulus (CS) that elicits the conditioned response (CR) of salivation

Neutral stimulus (metronome)

CS (metronome)

Conditioning procedure: during the classical conditioning procedure, the neutral stimulus is presented in association with the unconditioned stimulus (UCS) to elicit the unconditioned response (UCR)

UCR (salivation)UCR

(meat powder)

CR (salivation)

C

D

Pavlov’s Experiments

• Systematic, effective, precise studies

• Association of two stimuli

• The more frequently the metronome and food are associated, the more often the metronome will elicit salivation

• Timing of association is highly important– Longer time intervals were less effective;

almost no learning occurred


Number of drops of

saliva elicited by

metronome alone

Number of times metronome and meat powder were presented together

2

3

4

5

6

7

8

2

1

3 4 5 6 7 8 9 10 111

Pavlov’s Studies: the more often the metronome was associated in time with meat powder, the more effective in eliciting saliva

Pavlov’s Experiment

CR (salivation)

UCR (meat powder)

Before classical conditioning: initially, the metronome is a neutral stimulus that does not elicit the response of salivation

But the unconditioned stimulus (UCS) can elicit the unconditioned response (UCR)

UCR (salivation)

Neutral stimulus (metronome)

B

A

Terminology of Classical Conditioning

• Unconditioned stimulus (UCS) – Elicits response without learning

• Unconditioned response (UCR)– Unlearned, inborn response

• Conditioned stimulus (CS)– Acquires ability to elicit after paired

association with unconditioned stimulus

• Conditioned response (CR)– Elicited by conditioned stimulus


CS

UCS

(meat powder)

(metronome)

CRUCR (Salivation)

Application of Terminology to Pavlov’s Experiment

Definition of Classical Conditioning

• Form of learning in which– CS followed by UCS elicits UCR

– Pairing of CS and UCS allows CS to elicit CR almost identical or similar to UCR

• Considered learning because– New behavior acquired

– Old behavior elicited by new stimulus

– Does not depend on behavior of individual


Importance of Classical Conditioning

• Watson and Rayner – Made classical conditioning famous with

Little Albert experiments• Learned to fear rats - unethical today

• Watson and Jones– Counterconditioning: reversing the CR

• Useful in – Explaining aspects of human health– Explaining sexual fetishes and arousals


Watson and Raynor Study

CS

UCS

(rat)

(loud noise)

CRUCR

(fear)

Operant Conditioning: Learning from the Consequences of Your Behavior

• Form of learning – Consequences of behavior lead to change based

on probability of consequences occurring

• Thorndike and the puzzle box – Researching animal intelligence

– Law of effect: consequences determine response occurring in future


Operant Conditioning

• Three types of desirable and undesirable consequences that influence behavior

– Positive reinforcement

– Negative reinforcement

– Punishment


Reinforcement

• Positive reinforcers – learned and inborn

• Primary reinforcement – Innately reinforcing – Examples: food, water, warmth, physical activity

• Secondary reinforcement– Learned through classical conditioning– Examples: rewards, money, praise


Primary reinforcer

Secondary reinforcer

Schedules of Positive Reinforcement

• Continuous – reinforcer for every response

• Schedules – Fixed ratio – reinforcer given after each

specified or fixed number of responses

– Variable ratio – reinforcement after varying number of responses


Fixed Ratio Variable Ratio

Cu

mul

ativ

e re

spon

ses

Time

Cu

mul

ativ

e re

spon

ses

Time

Patterns of Behavior Produced by Reinforcement

Schedules of Positive Reinforcement

• Schedules– Fixed interval schedule – reinforcement

based on time (ie: every 2 hours)

– Variable interval schedule – reinforcement after variable amount of time (ie: reinforced after 1 hour, then after 4 minutes, then after 35 minutes like slot machine gambling)


TimeTime

Cu

mul

ativ

e re

spon

ses

Cu

mul

ativ

e re

spon

ses

Fixed Interval Variable Interval

Patterns of Behavior Produced by Reinforcement

Shaping

• Reinforcing steps toward targeted behavior or method of successive approximations

• Skinner – Skinner box– Rat pushes lever to get food after

• Rewarded for steps of nearing, touching, and pushing on lever

• Used for children and those with developmental handicaps


Operant Conditioning

Electric gridFood cup

Dispenser tube

Pellet dispenser

Lever

Signal lights

Speaker

To shock generator

Negative Reinforcement

• Something unpleasant, aversive, undesired is removed by behavior or does not happen at all– Not the same as punishment– Not a bad habit being reinforced– Very powerful method of reinforcement

• Escape conditioning – negative event stops

• Avoidance conditioning – negative event avoided


Punishment

• Consequence of behavior is negative– Behavior has been punished

– Behavior frequency will decrease

– When appropriately used – ethical and valuable tool for discouraging undesired behavior

• Physical punishment used by society, parents, and others – has dangers– Raises ethical questions


Dangers of Punishment

• Often reinforcing to the punisher

• Often has generalizing effect on the individual

• May lead to a worse problem (learning to dislike punisher, reacting aggressively towards others)

• Criticism trap – belief that punishment is ineffective leads to using criticism (criticism sometimes reinforces negative behavior)

• Punishment may suppress behavior temporarily but is not long term solution


Guideline for Use of Punishment

• Do not use physical punishment

• Punish inappropriate behavior immediately

• Positively reinforce appropriate behavior

• Clarify what behavior is being punished and why (separate the person from the behavior)

• Do not mix punishment with rewards

• Do not back down once you begin to punish



Contrasting Classical and Operant Conditioning

Classical conditioning involves– Association between

two stimuli– Reflexive, involuntary

behaviors– UCS making behavior

happen

Operant conditioning involves– Association between

response and consequence

– More complicated voluntary behaviors

– Reinforcing consequence occurring only if desired response is given


Stimulus Discrimination and Generalization

• Stimulus discrimination – deciding between appropriate and inappropriate occasions for a response– Learned by humans and animals

• Stimulus generalization – opposite of stimulus discrimination– Similarity of two or more stimuli

100

300

480 0

500 520

Mea

n to

tal r

espo

nses

560 580 600 640460 620

200

540

Wavelength

Stimulus Generalization and Reinforcement of a Pigeon’s Pecking


Extinction: Learning When to Quit

• Extinction – learned response stops occurring because

original source of learning was removed

• Classical conditioning– Fear is very difficult to extinguish– CR extinguished if CS is repeatedly presented

but UCS is no longer paired with it

• Operant conditioning– Extinction results from change in consequence


Extinction

• Differences between classical conditioning and operant conditioning

• Operant conditioning– Early stage extinction leads to frustration

– Partial reinforcement effect: schedule and type of reinforcement greatly influence extinction

• Fastest extinction - continuous reinforcement

– Response prevention: extinguishes avoidance responses quickly


Spontaneous Recovery and Disinhibition

• Course of extinction not smooth – learned response occurs often before extinction

• Spontaneous recovery– Response reappears during extinction

• Disinhibition– Presentation of intense, unrelated stimulus can

cause strength of response to return– Pavlov: no response is unlearned, just inhibited


Theoretical Interpretations of Learning

• Pavlov – Neural connections between brain areas of learning and responding acquired

• Other psychologists– Cognition plays central role in learning

• Place learning and cognitive map

• Latent learning

• Insight learning – sudden problem solving

• Learning set – learned to learn insightfully

Monkeys and Impact of Experience

110

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90

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2

Per

cent

of

corr

ect r

espo

nses

503 4 5 61

120

Trials

1-8

Problems

17-2425-32101-200

201-256257-312

9-16


Modeling: Learning by Watching Others

• Bandura – people learn through modeling– Demonstrates role of cognition in learning

– Cognitive learning occurs by watching before behavior occurs• Learn skills• Use of appropriate behavior in given situation• Reduce inhibitions• Learn what behaviors are reinforced


Modeling

• Powerful form of learning

• Vicarious reinforcement – likely to imitate reinforced behaviors

• Vicarious punishment – likely not to imitate behaviors that are punished

• High status, attractive, likeable, successful models more likely imitated– Concerns about television, movies, other media


Biological Factors in Learning

• Learning influenced several ways– Physical ability limitations (ie: fish cannot fly)

– Individual differences – (ie: fear inhibitions)

– Process of evolution – useful fears and survival mechanisms • Biological preparedness to learn• Learned taste aversion ( used on humans

and animals)

The End


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Basic Principles of Learning