Animal ResearchAnimal Research

Problem of Variability of human participantsProblem of Variability of human participants Use Animals to increase controlUse Animals to increase control

Rearing - littermatesRearing - littermates Genetics – littermates, inbred strains Genetics – littermates, inbred strains Experience- what they were exposed toExperience- what they were exposed to Environmental conditions – food, water, lighting, Environmental conditions – food, water, lighting,

temperature, cage size, etc.temperature, cage size, etc.

Use of animalsUse of animals

To reduce variabilityTo reduce variability To study basic processesTo study basic processes To study special variables that can’t be tested To study special variables that can’t be tested

in humans – e.g. brain functionin humans – e.g. brain function To learn more about animalsTo learn more about animals

Research DesignsResearch Designs

Random GroupsRandom Groups Split litter (Matched groups)Split litter (Matched groups) Within subjectsWithin subjects Mixed designsMixed designs Small N design (ABA design)Small N design (ABA design) Classical ConditioningClassical Conditioning Instrumental ConditioningInstrumental Conditioning Ethological methodsEthological methods

Classical ConditioningClassical Conditioning

PavlovPavlov DigestionDigestion SalivationSalivation DogsDogs Inappropriate salivationInappropriate salivation Psychic secretionsPsychic secretions UCS, UCR, CS, CR, contiguityUCS, UCR, CS, CR, contiguity

Classical Conditioning of drug Classical Conditioning of drug related stimulirelated stimuli

UCS = morphineUCS = morphine UCR = Heart rate decreaseUCR = Heart rate decrease CS = drug stimuliCS = drug stimuli CR = ??CR = ??

CR = heart rate up!CR = heart rate up! Compensatory responseCompensatory response

Drug OverdoseDrug Overdose

CS is differentCS is different UCS = same as beforeUCS = same as before CR = no compensatory responseCR = no compensatory response Heart rate too low – person diesHeart rate too low – person dies

Contiguity TheoryContiguity Theory

Pavlov’s explanationPavlov’s explanation Two events that occur closely together will Two events that occur closely together will

become associatedbecome associated Temporal contiguityTemporal contiguity Spatial contiguitySpatial contiguity

Methods in Classical ConditioningMethods in Classical Conditioning

Tests of Contiguity theoryTests of Contiguity theory CS – UCS temporal relationshipsCS – UCS temporal relationships

Square wave diagramSquare wave diagram Simultaneous conditioningSimultaneous conditioning

resultsresults Delayed conditioningDelayed conditioning

Short – delayShort – delay Long - delayLong - delay

Trace conditioningTrace conditioning Short – delayShort – delay Long - delayLong - delay

Backward conditioningBackward conditioning

Inhibitory Classical ConditioningInhibitory Classical Conditioning

Excitatory classical ConditioningExcitatory classical Conditioning A CR is producedA CR is produced

Inhibitory classical conditioningInhibitory classical conditioning A CR is inhibitedA CR is inhibited Must first have excitatory to demonstrate Must first have excitatory to demonstrate

inhibitoryinhibitory Pop quiz examplePop quiz example

Higher – Order conditioningHigher – Order conditioning

DiagramDiagram Sequence of CSsSequence of CSs Waterfall exampleWaterfall example

Sensory PreconditioningSensory Preconditioning

Pair two stimuli for several trialsPair two stimuli for several trials Use one as a CS until you get CRsUse one as a CS until you get CRs Test other stimulusTest other stimulus Do you get a CR to second stimulus?Do you get a CR to second stimulus?

YesYes Pairing stimuli before training in some way Pairing stimuli before training in some way

makes them equivalentmakes them equivalent Evidence for S – S association in classical Evidence for S – S association in classical

conditioningconditioning CS – UCS association produces conditioningCS – UCS association produces conditioning

Other methods: PreexposureOther methods: Preexposure

CS pre-exposureCS pre-exposure Present CS alone for several trials (16-20trials)Present CS alone for several trials (16-20trials) Pair CS with UCS in excitatory conditoningPair CS with UCS in excitatory conditoning Test for CR Test for CR

UCS pre-exposureUCS pre-exposure Present UCS alone for several trialsPresent UCS alone for several trials Pair UCS with a CSPair UCS with a CS Test for CRTest for CR

Measuring the CRMeasuring the CR

Determining if CR occursDetermining if CR occurs Omit the UCSOmit the UCS

See if CR occursSee if CR occurs Problem: Extinction occursProblem: Extinction occurs

Probe trialsProbe trials See if CR occurs on probe trial only (e.g. 1/15)See if CR occurs on probe trial only (e.g. 1/15)

Measuring Strength of CRMeasuring Strength of CR Frequency –e.g. 7/10 probe trialsFrequency –e.g. 7/10 probe trials Latency – e.g. number second to produce CRLatency – e.g. number second to produce CR Magnitude – e.g. number of drops of saliva Magnitude – e.g. number of drops of saliva

DiscriminationDiscrimination

A tool to measure other behaviorsA tool to measure other behaviors Pavlov – discrimination of shape by dogsPavlov – discrimination of shape by dogs CS+ paired with ucs = CRCS+ paired with ucs = CR CS- not paired with ucs = no CRCS- not paired with ucs = no CR Experimental neurosisExperimental neurosis

CS+ = circleCS+ = circle CS- = ellipse (9:1)CS- = ellipse (9:1) Dogs became neuroticDogs became neurotic

GeneralizationGeneralization

A tool to study other behaviorsA tool to study other behaviors Train on one CS (e.g. cs = red)Train on one CS (e.g. cs = red) Test on new CS’s (orange, bluish red, etc)Test on new CS’s (orange, bluish red, etc) The more similar the new CS’s the more The more similar the new CS’s the more

generalization that occursgeneralization that occurs Generalizaton gradientGeneralizaton gradient Training one stimulus trains a whole host of Training one stimulus trains a whole host of

stimulistimuli

ExtinctionExtinction

As a tool to measure the strength of CRAs a tool to measure the strength of CR Present CS without UCSPresent CS without UCS CR dies out or extinguishesCR dies out or extinguishes Pavlov – extinction involves the active Pavlov – extinction involves the active

withholding of the CRwithholding of the CR Spontaneous recoverySpontaneous recovery Faster relearningFaster relearning

Instrumental ConditioningInstrumental Conditioning

Instrumental/Operant =The consequences of a Instrumental/Operant =The consequences of a response change the future probability of the response change the future probability of the responseresponse

Classical vs InstrumentalClassical vs Instrumental Subject passive subject activeSubject passive subject active Stimuli imposed stimuli unknownStimuli imposed stimuli unknown Behavior Behavior elicitedelicited Behavior Behavior emittedemitted S – S; S – R R – S S – S; S – R R – S Autonomic mainly skeletal mainlyAutonomic mainly skeletal mainly

Pre-training ProceduresPre-training Procedures

DeprivationDeprivation 85-90% body weight85-90% body weight Weigh daileyWeigh dailey Calculate food amountsCalculate food amounts

HandlingHandling Sampling the reinforcerSampling the reinforcer Adaptation to apparatusAdaptation to apparatus Magazine trainingMagazine training

Pre-training (Cont.)Pre-training (Cont.)

Measure operant levelMeasure operant level ShapingShaping

AutoshapingAutoshaping Successive approximationSuccessive approximation

Now ready to start experimentNow ready to start experiment

Instrumental DesignsInstrumental Designs

Free Operant (Skinner)Free Operant (Skinner) Operant chamberOperant chamber Animal free to make response at any timeAnimal free to make response at any time DV = rate of responding (responses/unit time)DV = rate of responding (responses/unit time) Cumulative responsesCumulative responses Cumulative recorderCumulative recorder Interpret graphs of dataInterpret graphs of data Small-n designSmall-n design

Discrete TrialDiscrete Trial

Response can only occur at a time specified by Response can only occur at a time specified by the researcher (Thorndike and others)the researcher (Thorndike and others)

Many possible DVsMany possible DVs Latency – straight alley, Morris water mazeLatency – straight alley, Morris water maze Speed of response – straight alleySpeed of response – straight alley Choice – T-mazeChoice – T-maze Percent correct – Stone maze, WGTAPercent correct – Stone maze, WGTA Errors – complex mazeErrors – complex maze

ReinforcementReinforcement

A reinforcer is any thing (stimulus) that A reinforcer is any thing (stimulus) that increasesincreases the probability of the response that it the probability of the response that it follows.follows.

Must make sure that a stimulus actually is a Must make sure that a stimulus actually is a reinforcer first before using it to change reinforcer first before using it to change behaviorbehavior

E.g “gold stars”E.g “gold stars”

Types of ReinforcementTypes of Reinforcement

Positive ReinforcementPositive Reinforcement A response, followed by the presentation of a A response, followed by the presentation of a

reinforcing stimulus, increases the future reinforcing stimulus, increases the future probability of the response.probability of the response.

A hungry rat presses a lever to get foodA hungry rat presses a lever to get food Mom gives junior a cookie for picking up his toysMom gives junior a cookie for picking up his toys

Negative ReinforcementNegative Reinforcement

Also called “escape training”Also called “escape training” A response, followed by the withdrawal of the A response, followed by the withdrawal of the

reinforcing stimulus, reinforcing stimulus, increasesincreases the future the future probability of the responseprobability of the response A rat jumps a low hurdle and a loud noise is turned A rat jumps a low hurdle and a loud noise is turned

offoff A person, stopped at a red light, rolls up the car A person, stopped at a red light, rolls up the car

window to decrease the sound of a jack hammer window to decrease the sound of a jack hammer working on the concrete curbworking on the concrete curb

PunishmentPunishment

A punisher is any thing (stimulus) that A punisher is any thing (stimulus) that decreasesdecreases the probability of the response that it the probability of the response that it follows.follows.

Must check to see that a stimulus is a punisherMust check to see that a stimulus is a punisher E.g. tantrums E.g. tantrums

Types of PunishmentTypes of Punishment

Punishment by presentationPunishment by presentation A response, followed by the presentation of a A response, followed by the presentation of a

punishing stimulus, becomes less probable in punishing stimulus, becomes less probable in the futurethe future A rat, steps off a pedestle and gets shockedA rat, steps off a pedestle and gets shocked Johnny hits his sister and gets spanked by dadJohnny hits his sister and gets spanked by dad

(What’s Johnny learning here?)(What’s Johnny learning here?)

Punishment by withdrawalPunishment by withdrawal

Also called “ omission training”Also called “ omission training” A response, followed by the withdrawal of a A response, followed by the withdrawal of a

positive reinforcer, positive reinforcer, decreases decreases the future the future probability of the responseprobability of the response A rat, presses a lever, and as a result, loses access A rat, presses a lever, and as a result, loses access

to food for 60 secondsto food for 60 seconds Johnny hits his sister, and as a result, doesn’t get to Johnny hits his sister, and as a result, doesn’t get to

watch his favorite violent cartoon showwatch his favorite violent cartoon show

Categories of ReinforcementCategories of Reinforcement

PrimaryPrimary UnlearnedUnlearned PhysiologicalPhysiological

FoodFood WaterWater SexSex PainPain

Categories of ReinforcementCategories of Reinforcement

Secondary/ConditionedSecondary/Conditioned LearnedLearned Neutral initiallyNeutral initially Paired with a primary reinforcerPaired with a primary reinforcer Tokens/token economiesTokens/token economies

ChimpsChimps Strip mines Strip mines

Categories of ReinforcementCategories of Reinforcement

SocialSocial

AttentionAttention

AffectionAffection

Praise Praise

Trans-situationalTrans-situational

Paired with several reinforcersPaired with several reinforcers

Money Money

Schedules of ReinforcementSchedules of Reinforcement

Simple Schedules (only one requirement for Simple Schedules (only one requirement for reinforcement)reinforcement)

Ratio Schedules (responses)Ratio Schedules (responses) Fixed RatioFixed Ratio Variable RatioVariable Ratio

Interval Schedules (time)Interval Schedules (time) Fixed IntervalFixed Interval Variable IntervalVariable Interval

Ratio SchedulesRatio Schedules

Fixed Ratio (e.g. FR10)Fixed Ratio (e.g. FR10) Number of responses per reinforcement is fixed Number of responses per reinforcement is fixed

and unchangingand unchanging No reinforcement for responses until the ratio is No reinforcement for responses until the ratio is

completed: last response produces reinforcercompleted: last response produces reinforcer In well trained subjects:In well trained subjects:

Ratio is run off all at onceRatio is run off all at once Post-reinforcement pausePost-reinforcement pause E.g. piece workE.g. piece work

Variable RatioVariable Ratio

Variable Ratio (VR10)Variable Ratio (VR10) Number of responses required is constantly Number of responses required is constantly

changing from one reinforcement to the nextchanging from one reinforcement to the next UnpredictableUnpredictable

Best strategy:Best strategy: Work fastWork fast Work consistentlyWork consistently E.g. gamblingE.g. gambling

Interval SchedulesInterval Schedules

Fixed Interval (FI60)Fixed Interval (FI60) Amount of time that must pass between Amount of time that must pass between

reinforcements is fixed.reinforcements is fixed. PredictablePredictable

Best strategy:Best strategy: Wait until appropriate amount of time has passedWait until appropriate amount of time has passed

Scallop shaped recordsScallop shaped records E.g. test datesE.g. test dates

Variable IntervalVariable Interval

Variable Interval (VI60)Variable Interval (VI60) Amount of time that must pass between Amount of time that must pass between

reinforcements is constantly changingreinforcements is constantly changing UnpredictableUnpredictable Best strategy:Best strategy: Work consistentlyWork consistently E.g. pop quizzesE.g. pop quizzes A tool for studying other behaviorsA tool for studying other behaviors

Complex SchedulesComplex Schedules

More than one requirement must be metMore than one requirement must be met Often used as tools to study other aspects of Often used as tools to study other aspects of

researchresearch DRLDRL Progressive ratioProgressive ratio

DiscriminationDiscrimination

Differential responding to stimuliDifferential responding to stimuli Sd – sets occasion for reinforcementSd – sets occasion for reinforcement S-delta – sets occasion for non-reinforcementS-delta – sets occasion for non-reinforcement

As in classical conditioning, discrimination can be As in classical conditioning, discrimination can be used as a tool to study other behaviorsused as a tool to study other behaviors

E.g. recognition memory in monkeys using DNMSE.g. recognition memory in monkeys using DNMS

GeneralizationGeneralization

Same as in classical conditioningSame as in classical conditioning Can be used to study other behaviorsCan be used to study other behaviors Reinforce behavior in presence of one Reinforce behavior in presence of one

stimulus, look at how the behavior generalizes stimulus, look at how the behavior generalizes to other similar stimulito other similar stimuli

E.g. taking notes in biology class – taking E.g. taking notes in biology class – taking notes in psychology class.notes in psychology class.

ExtinctionExtinction

Also like classical conditioningAlso like classical conditioning Used to study other behaviorsUsed to study other behaviors E.g. preference for a reinforced location in the E.g. preference for a reinforced location in the

Morris water maze. Morris water maze. Study annulus crossings during extinctionStudy annulus crossings during extinction