copyright © allyn and bacon 2009 1 chapter 3 learning and human nature this multimedia product and...

Copyright © Allyn and Bacon 2009

11

Chapter 3Chapter 3

Learning and Learning and Human NatureHuman Nature

This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or part, of any images; any rental, lease, or lending of the program. ISBN: 0-205-42428-7

22Copyright © Allyn and Bacon 2009

Learning vs. InstinctsLearning vs. Instincts

Learning – A process through which experience produces lasting change in behavior or mental processes

Habituation-Learning not to respond to stimulation

Instincts-Motivated behaviors that have a strong innate basis


Behavioral learning – Forms of learning that can be described in terms of stimuli and responses (e.g. classical and operant conditioning)

LearningLearning

Mere exposure effect – Learned preference for stimuli to which we have been previously exposed


Classical conditioning is a basic form of learning in which

a stimulus that produces an innate reflex becomes

associated with a previously neutral stimulus, which then acquires the power to elicit

essentially the same response

What Sort of Learning Does What Sort of Learning Does Classical Conditioning Explain?Classical Conditioning Explain?


The Essentials of Classical The Essentials of Classical ConditioningConditioning

Neutral stimulus – Any stimulus that produces no conditioned response prior to learning

Acquisition – Initial learning stage in classical conditioning

• conditioned response (CR) becomes elicited by the conditioned stimulus (CS)


Basic Features of Basic Features of Classical ConditioningClassical Conditioning

Unconditioned Unconditioned response (UCR)response (UCR)

Unconditioned Unconditioned stimulus (UCS)stimulus (UCS)

Conditioned Conditioned response (CR)response (CR)

Conditioned Conditioned stimulus (CS)stimulus (CS)



Unconditioned response (UCR)

Unconditioned Unconditioned stimulus (UCS)stimulus (UCS)

Conditioned response (CR)

Conditioned stimulus (CS)

The stimulus that elicits an unconditioned response



Unconditioned Unconditioned response (UCR)response (UCR)

Unconditioned stimulus (UCS)



The response elicited by an unconditioned stimulus without prior learning






Conditioned Conditioned stimulus (CS)stimulus (CS)

A previously neutral stimulus that comes to elicit the conditioned response





Conditioned Conditioned response (CR)response (CR)


A response elicited by a previously neutral stimulus that has become associated with the conditioned stimulus


Classical ConditioningClassical ConditioningPrior to conditioning

Conditioning

After conditioning

Neutral stimulus(tone)

(Orientation to soundbut no response)

Unconditioned stimulus(food powder in mouth)

Unconditioned response(salivation)

Neutral stimulusCS (tone)

Unconditioned stimulus(food powder)

+Conditioned response

(salivation)

Conditioned stimulus(tone)

Conditioned response(salivation)


Classical ConditioningClassical Conditioning

Extinction – Weakening of a conditioned association in the absence of an unconditioned stimulus or reinforcer

Spontaneous recovery –Reappearance of an extinguished conditioned response after a time delay


Acquisition, Extinction, and Acquisition, Extinction, and Spontaneous RecoverySpontaneous Recovery

(1)Acquisition(CS + UCS)

(3)Spontaneous Recovery(CS alone)

Res

t per

iod(2)

Extinction(CS alone)

(Time)

Trials

Str

engt

h of

the

CR

(Wea

k)(S

tron

g)


Classical Conditioning:Classical Conditioning:Generalization and DiscriminationGeneralization and Discrimination

Stimulus generalization involves giving a conditioned response to stimuli that are similar to the CS

Stimulus discrimination involves responding to one stimulus butnot to stimuli that are similar

Confusing stimuli may cause experimental neurosis


Applications of Classical ConditioningApplications of Classical Conditioning

Conditioned Food Aversions– Biological tendency in which an organism learns to avoid food with a certain sight, smell, or taste after a single experience, if eating it is followed by illness


Biological Predispositions:Biological Predispositions:A Challenge to PavlovA Challenge to Pavlov

Garcia & Koelling (1966) findings-

• Selective CS-UCS connection

• Innate disposition to associations

Why are some stimuli-consequence combinations readily learned while other combinations are highly resistant to learning?

What any organism can or cannot learn in a given setting is due in part to its evolutionary history


How Do We LearnHow Do We LearnNew Behaviors byNew Behaviors by

Operant Conditioning?Operant Conditioning?

In operant conditioning, the consequences of behavior,

such as rewards and punishments, influence the probability that the behavior

will occur again


How Do We LearnHow Do We LearnNew Behaviors byNew Behaviors by

Operant Conditioning?Operant Conditioning?

Trial-and-error learning – Learner gradually discovers the correct response by attempting many behaviors and noting which ones produce the desired consequences

Thorndike-law of effect


Skinner’s Radical BehaviorismSkinner’s Radical Behaviorism

B.F. Skinner believed that the most powerful influences on behavior are its consequences

“The power of reinforcement”

• reward = conditions that follow and strengthen a response

• Operant chamber

Copyright © Allyn & Bacon 2009

2121


The Power of ReinforcementThe Power of Reinforcement

Positive reinforcers –Stimulus presented after a response that increases the probability of that response happening again

• Positive = add or apply

Negative reinforcers – Removal of an unpleasant stimulus, that increases the probability of that response happening again

• Negative = subtract or remove


Contingencies of Reinforcement:Contingencies of Reinforcement:

Varying the timing and frequency of reinforcement

Continuous reinforcement – Reinforcement schedule in which all correct responses are reinforced

Partial (intermittent) reinforcement – Reinforcement schedule in which some, but not all, correct responses are reinforced


Schedules of ReinforcementSchedules of Reinforcement

Ratio schedules – Provide reward after a certain number of responses

Interval schedules – Provide reward after a certain time interval

Fixed Ratio (FR)Fixed Ratio (FR)

Fixed Interval (FI)Fixed Interval (FI)

Variable Ratio (VR)Variable Ratio (VR)

Variable Interval (VI)Variable Interval (VI)



Fixed Ratio (FR)Fixed Ratio (FR)

Fixed Interval (FI)

Variable Ratio (VR)

Variable Interval (VI)

Rewards appear after a certain set number of responses

e.g. factory workers getting paid after every 10 cases of product are completed



Fixed Ratio (FR)

Fixed Interval (FI)

Variable Ratio Variable Ratio (VR)(VR)


Rewards appear after a certain number of responses, but that number varies from trial to trial

e.g. slot machine pay-offs



Fixed Ratio (FR)

Fixed Interval Fixed Interval (FI)(FI)

Variable Ratio (VR)


Rewards appear after a certain fixed amount of time, regardless of number of responses

e.g. weekly or monthly paychecks



Fixed Ratio (FR)

Fixed Interval (FI)

Variable Ratio (VR)

Variable Interval Variable Interval (VI)(VI)

Rewards appear after a certain amount of time, but that amount varies from trial to trial

e.g. random visits from the boss who delivers praise



Primary reinforcers – Reinforcers that fulfill basic biological needs or desires, such as food and sex, that have an innate basis to an organism



Secondary (conditioned) reinforcers – Stimuli, such as money or tokens, that acquire their reinforcing power by their learned association with primary reinforcers


Factors that can influence Factors that can influence the effectiveness of reinforcementthe effectiveness of reinforcement

Instinctive drift-innate response tendencies interfere with learned behaviors; innate tendencies can override behaviors learned through reinforcement

e.g., reinforcing your cat to not scratch the furniture

Premack principle-

a preferred activity can reinforce a less preferred activity

e.g., children sitting quietly in class in order to go out for recess


PunishmentPunishment

Punishment – An aversive stimulus which diminishes the strength of the response it follows

How does this differ from negative reinforcement?


Punishment vs. Negative Punishment vs. Negative ReinforcementReinforcement

Loud Noise Press Lever

Press Lever

Loud Noise Removed

Loud Noise Applied

Response ConsequenceNegative Reinforcement

Punishment

No Noise


Types of PunishmentTypes of Punishment

Positive punishment – The application or presentation of an aversive stimulus after a response

Negative punishment –The removal of an attractive stimulus after a response

Both attempt to decrease the likelihood that a behavior will reoccur


Four Kinds of ConsequencesFour Kinds of Consequences

Positive(Add)

Negative(Subtract)

STIMULUS

DecreaseBehavior

PositivePunishment

Getting speeding ticketleads to less speeding

PositivePunishment

Missing dinner leads to less staying out late

IncreaseBehavior

PositiveReinforcementBonus for working hard leads to more hard work

NegativeReinforcement

Aspirin relieving headache

leads to more aspirin use

GO

AL


The Use of PunishmentThe Use of Punishment

Punishment can result in immediate change in behavior, often making it an easy solution; should be a logical consequence to make it work


The Abuse of PunishmentThe Abuse of Punishment

Problems associated with punishment:

• Power of use usually disappears when threat of punishment is removed

• Rewards can override/overpower the punishment

• Often triggers escape or aggression

• Teaches legitimate use of aggression to influence others

• May inhibit learning new and better responses

• Is often applied unequally


When does punishment work?When does punishment work?

• when presented without delay

• when consistent

• when limited in duration and intensity

• when consequence is logical

• limited to the specific situation at hand

• when no mixed messages are sent

• when negative punishment is used


A checklist for Modifying Operant BehaviorA checklist for Modifying Operant Behavior

Consider combining the following:

Positive reinforcement-encourage desirable behaviors

Punishment-use logical consequences, swiftly, without undue harm

Negative reinforcement

Extinction-control all possible reinforcers


Inset table to illustrate comparison of Classical and Operant Conditioning (pg. 3-40)


Operant and Classical Conditioning Operant and Classical Conditioning ComparedCompared

Classical conditioning involves the association of two stimuli (UCS + CS) before the response or behavior

Operant conditioning involves a reinforcing (reward) or punishing stimulus after a response or behavior


How DoesHow DoesCognitive PsychologyCognitive Psychology

Explain Learning?Explain Learning?

According to cognitive psychology, some forms of learning must be explained

as changes in mental processes, rather than as changes in behavior alone




Insight learning – Problem solving occurs by suddenly perceiving new forms or relationships

Cognitive maps –A mental image used to navigate through a familiar environment




Latent learning-

when learning occurs without reinforcement and without any hint that learning took place

cognitive explanation of learningvs. the behavioral explanation


Observational Learning: Bandura’s Observational Learning: Bandura’s Challenge to BehaviorismChallenge to Behaviorism

Observational learning (social learning)–

• form of cognitive learning

• new responses are acquired after watching others’ behavior and consequences of their behavior


Rethinking Behavioral Learning in Rethinking Behavioral Learning in Cognitive TermsCognitive Terms

Cognitive-behavioral psychologists

• associations occur when the organism is seen as an information seeker using logical and perceptual relations among events

• reinforcement changes expectations for future rewards or punishments


Brain Mechanisms and LearningBrain Mechanisms and Learning

Long-term potentiation –

• Biological process involving physical changes that strengthen the synapses in groups of nerve cells

• believed to be the neural basis of learning



Extinction-

• forgetting unimportant associations

• neurotransmitters block memories• glutamate; norephinephrine



Learning circuitry-

• Simpler circuits• Classical conditioning and operant learning

• Complex learning-• Concept formation, insight learning, and

observational learning



Observational learning and mirror neurons• Neurons that help us imitate others’

behaviors

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