NeobehavioristsNeobehaviorists

NeobehaviorismNeobehaviorism

Life after WatsonLife after Watson

OptimismOptimism

But….But….

NeobehavioristsNeobehaviorists

Influence by Watson?....Clearly.Influence by Watson?....Clearly. HullHull

TolmanTolman

SkinnerSkinner

Clark HullClark HullHull (1884-1952)Hull (1884-1952)

Ph.D from University of Wisconsin in Ph.D from University of Wisconsin in 19181918

Invited to Yale in 1929Invited to Yale in 1929

President of APA in 1935President of APA in 1935

Hull –Early InterestsHull –Early Interests

University of WisconsinUniversity of Wisconsin Books:Books:

Aptitude TestingAptitude Testing (1928) (1928) Hypnosis and SuggestibilityHypnosis and Suggestibility (1933) (1933)

32 papers32 papers

Hull’s System - YaleHull’s System - Yale

Stimuli and responses are assumed Stimuli and responses are assumed to be bridged by intervening to be bridged by intervening variables such as:variables such as:

DriveDrive FatigueFatigue Habit strengthHabit strength IncentiveIncentive

Hull’s SystemHull’s System

Example:Example:

SSEERR = = SSHHRR x D x V x K x D x V x K

E refers to action potential in a given situationE refers to action potential in a given situation H refers to habit strength (or number of previous trials in the H refers to habit strength (or number of previous trials in the

situation)situation) D is drive strength (e.g., the number of hours of deprivation)D is drive strength (e.g., the number of hours of deprivation) V refers to stimulus intensityV refers to stimulus intensity K refers to incentive motivationK refers to incentive motivation

Hull’s TheoryHull’s Theory

Reinforcement:Reinforcement: Played a key rolePlayed a key role

Law of reinforcement:Law of reinforcement: Stimuli that reduce drive stimuli are reinforcing.Stimuli that reduce drive stimuli are reinforcing.

Secondary reinforcementSecondary reinforcement Any stimulus consistently associated with Any stimulus consistently associated with

primary reinforcers takes on reinforcing primary reinforcers takes on reinforcing properties.properties.

Hull - LegacyHull - Legacy

Central figure in the development of Central figure in the development of quantitative approaches to behavior.quantitative approaches to behavior.

Principles of BehaviorPrinciples of Behavior (1943) (1943) A Behavior SystemA Behavior System (1952) (1952)

Edward C. TolmanEdward C. Tolman

Tolman (1886-1959)Tolman (1886-1959)

Graduates with B.S. from MIT (1911)Graduates with B.S. from MIT (1911)

Harvard (1915) – Ph.D in PsychologyHarvard (1915) – Ph.D in Psychology

President APA (1937)President APA (1937)

Tolman’s SystemTolman’s System

Great range of topics that we encounter in Great range of topics that we encounter in our daily livesour daily lives

Focus on the role of cognition and purposeFocus on the role of cognition and purpose

Wanted a psychology with true breadth of Wanted a psychology with true breadth of perspective that retained the desirable perspective that retained the desirable objective features of classical behaviorism.objective features of classical behaviorism.

Tolman’s SystemTolman’s System

Believed that psychological processes Believed that psychological processes intervene between stimuli and responses.intervene between stimuli and responses.

Intervening variables:Intervening variables: CognitionsCognitions ExpectanciesExpectancies PurposesPurposes HypothesesHypotheses AppetiteAppetite

Example:Example:

Expectancies:Expectancies:

Develops when a reward follows each Develops when a reward follows each successful response.successful response.

Then becomes involved in directing and Then becomes involved in directing and controlling behaviorcontrolling behavior

Tolman - ReinforcementTolman - Reinforcement

A reinforcer (e.g., food) has nothing to A reinforcer (e.g., food) has nothing to do with learning, as such, but do do with learning, as such, but do regulate the performance of learned regulate the performance of learned responses.responses.

Learning vs. Reinforcement vs. PerformanceLearning vs. Reinforcement vs. Performance

Cognitive mapsCognitive maps

Tolman - ReinforcementTolman - Reinforcement

Latent learningLatent learning

Reinforcement influences motivation Reinforcement influences motivation and hence performance, but learning and hence performance, but learning itself is an independent process.itself is an independent process.

Tolman’s - LegacyTolman’s - Legacy

Behaviorism could be more…Behaviorism could be more…

Set up the cognitive movement…Set up the cognitive movement…

Springboard for work in:Springboard for work in: MotivationMotivation Clinical PsychologyClinical Psychology NeuropsychologyNeuropsychology

B.F. SkinnerB.F. Skinner

Skinner BoxSkinner Box

Skinner BoxSkinner Box

Skinner’s Basic Law of Skinner’s Basic Law of Operant ConditioningOperant Conditioning

A response that is followed by a A response that is followed by a reinforcer is strengthened and is reinforcer is strengthened and is therefore more likely to occur again.therefore more likely to occur again.

A A reinforcer reinforcer is a stimulus or event is a stimulus or event that increases the frequency of a that increases the frequency of a response it follows.response it follows.

Operant ConditioniingOperant Conditioniing

1) The reinforcer must follow the 1) The reinforcer must follow the response.response.

2) The reinforcer must follow 2) The reinforcer must follow immediately.immediately.

3) The reinforcer must be contingent 3) The reinforcer must be contingent on the response. on the response.

What Behaviors Can Be What Behaviors Can Be Reinforced?Reinforced?

AcademicAcademic SocialSocial PsychomotorPsychomotor AggressionAggression Criminal ActivityCriminal Activity

Basic Concepts in OCBasic Concepts in OC

Shaping (Successive approximations)Shaping (Successive approximations) Shaping is a means of teaching a Shaping is a means of teaching a

behavior when the free operant level for behavior when the free operant level for that behavior is very low (or when the that behavior is very low (or when the desired terminal behavior is different in desired terminal behavior is different in form from any responses that the form from any responses that the organism exhibits).organism exhibits).

The Nature of ReinforcersThe Nature of Reinforcers

Primary Reinforcer:Primary Reinforcer: One that satisfies a built-in (perhaps One that satisfies a built-in (perhaps

biological) need or desire. biological) need or desire. Examples:Examples:

FoodFood WaterWater OxygenOxygen WarmthWarmth

The Nature of ReinforcersThe Nature of Reinforcers

Secondary (Conditioned) Reinforcers:Secondary (Conditioned) Reinforcers: A previously neutral stimulus that has A previously neutral stimulus that has

become reinforcing to an organism become reinforcing to an organism through repeated association with through repeated association with another reinforcer.another reinforcer.

Examples:Examples: PraisePraise Good gradesGood grades $$$$$$ Feelings of successFeelings of success

What Kinds of Consequences What Kinds of Consequences Do We Find Reinforcing?Do We Find Reinforcing?

Activity reinforcersActivity reinforcers An opportunity to engage in a favorite An opportunity to engage in a favorite

activity.activity. Premack Principle:Premack Principle:

A normally high-frequency response, when it A normally high-frequency response, when it follows a normally low-frequency response, follows a normally low-frequency response, will increase the frequency of the low-will increase the frequency of the low-frequency response.frequency response.

What Kinds of Consequences What Kinds of Consequences Do We Find Reinforcing?Do We Find Reinforcing?

Material reinforcersMaterial reinforcers Actual objects like food or toysActual objects like food or toys

Social reinforcersSocial reinforcers Gesture or sign from one person to Gesture or sign from one person to

another that communicates positive another that communicates positive regard like praise or a smile.regard like praise or a smile.

What Kinds of Consequences What Kinds of Consequences Do We Find Reinforcing?Do We Find Reinforcing?

Positive feedback:Positive feedback: Provides information as to which Provides information as to which

responses are desirable (and which are responses are desirable (and which are not).not).

Examples: material and social Examples: material and social reinforcersreinforcers

What Kinds of Consequences What Kinds of Consequences Do We Find Reinforcing?Do We Find Reinforcing?

Intrinsic reinforcersIntrinsic reinforcers When an individual engages in a When an individual engages in a

response not because of any external response not because of any external reinforcers but because of the internal reinforcers but because of the internal good feelings (the intrinsic reinforcers) good feelings (the intrinsic reinforcers) that such a response brings.that such a response brings.

Examples: feelings of success, feeling Examples: feelings of success, feeling relieved, feeling proudrelieved, feeling proud

Schedules of ReinforcementSchedules of Reinforcement

Ratio Schedules:Ratio Schedules: A schedule in which reinforcement occurs A schedule in which reinforcement occurs

after a certain number of responses have after a certain number of responses have been emitted (fixed or variable)been emitted (fixed or variable)

Interval Schedules:Interval Schedules: A schedule in which reinforcement is A schedule in which reinforcement is

contingent on the first response emitted contingent on the first response emitted after a certain time interval has elapsed after a certain time interval has elapsed (fixed or variable.(fixed or variable.

Ratio SchedulesRatio Schedules

Fixed Ratio (FR):Fixed Ratio (FR): Reinforcer is presented after a certain Reinforcer is presented after a certain

constant number of responses have constant number of responses have occurred.occurred.

Example - 1:3 or 1:10 Example - 1:3 or 1:10

Produces a high and consistent response Produces a high and consistent response raterate

Ratio SchedulesRatio Schedules

Variable Ratio (VR):Variable Ratio (VR): Reinforcement is presented after a Reinforcement is presented after a

particular, yet changing, number of particular, yet changing, number of responses have been emitted.responses have been emitted.

Example – In a 1:5 VR you may first be Example – In a 1:5 VR you may first be reinforced after four responses, then after reinforced after four responses, then after seven more, then after three, etc.seven more, then after three, etc.

Interval SchedulesInterval Schedules

Fixed Interval (FI):Fixed Interval (FI): Reinforcement is contingent on the first Reinforcement is contingent on the first

response emitted after a certain fixed response emitted after a certain fixed time interval has elapsed. time interval has elapsed.

Example: The organism may be reinforced Example: The organism may be reinforced for the first response emitted after five for the first response emitted after five minutes have elapsed. minutes have elapsed.

Interval SchedulesInterval Schedules

Variable Interval (VI):Variable Interval (VI): Reinforcement is contingent on the first Reinforcement is contingent on the first

response emitted after a certain time response emitted after a certain time interval has elapsed, but the length of interval has elapsed, but the length of that interval keeps changing from one that interval keeps changing from one occasion to the next. occasion to the next.

Example – The organism may be reinforced Example – The organism may be reinforced for the first response after five minutes, then for the first response after five minutes, then the first response after eight minutes, then the first response after eight minutes, then the first response after two minutes, etc.the first response after two minutes, etc.

Operant vs. Classical ConditioningOperant vs. Classical Conditioning Operant Operant

ConditioningConditioning Better explains Better explains

voluntaryvoluntary activity. activity.

Consequences are Consequences are contingent on behavior.contingent on behavior.

StimuliStimuli follow follow behavior: behavior:

Rat runs maze, receives Rat runs maze, receives rewardreward

Classical Classical ConditioningConditioning Better explains Better explains

involuntaryinvoluntary activity. activity.

CS not contingent on CS not contingent on behavior.behavior.

Stimuli Stimuli precedeprecede behavior:behavior:

Bell (CS) precedes Bell (CS) precedes salivationsalivation

Observational LearningObservational Learning Modeling (Albert Bandura)Modeling (Albert Bandura)

People learn by observing the People learn by observing the behavior of othersbehavior of others

Learning occurs without Learning occurs without reinforcementreinforcement

Bandura study on Aggressive Bandura study on Aggressive BehaviorBehavior

Children watch film of adults Children watch film of adults hitting & kicking a dollhitting & kicking a doll

These children were more These children were more aggressive with the doll than aggressive with the doll than children who didn’t see the filmchildren who didn’t see the film

TV violence & Aggressive TV violence & Aggressive BehaviorBehavior

Correlational studies: Children who watch a Correlational studies: Children who watch a lot of violent TV behave more aggressivelylot of violent TV behave more aggressively

Best studies: TV watching controlled, real-Best studies: TV watching controlled, real-world behavior observed.world behavior observed.

Finding: TV violence seems to cause Finding: TV violence seems to cause increase in aggressive behavior (mainly in increase in aggressive behavior (mainly in children who were already aggressive)children who were already aggressive)

Modeling Prosocial BehaviorModeling Prosocial Behavior Bandura study: Preschool Bandura study: Preschool

children overcoming fear of dogschildren overcoming fear of dogs Bandura study: Shy children Bandura study: Shy children

learn to interact with otherslearn to interact with others