1Chapter 11: BiologicalDispositions in LearningChapter Outline• Preparedness & Conditioning– Pavlovian conditioning– Operant conditioning• Operant-Pavlovian interactions– Instinctive drift– Sign tracking• Adjunctive behavior– Procedure and defining characteristics–Adjunctive behavior in humans–Adjunctive behavior as displacement activity• Activity anorexia– Procedure and defining characteristics– Comparison with anorexia nervosa–Underlying mechanisms & clinical implications• behavior systems theory2Preparedness & Conditioning•Pavlovian conditioning• Operant conditioningPreparedness & Pavlovian Conditioning• Equipotentiality hypothesis“Any natural phenomenon chosen at will may be convertedinto a conditional stimulus…any visual stimulus, anydesired sound, any sound, and the stimulation of any partof the skin” (Pavlov, 1928, p. 86)• Garcia & Koelling (naturalistic observation of behavior )– Investigated taste aversion learning in rats– Bait shyness – when left bait, rats consume small amount at first, ifthey survive they never touch it again– As expected – Bait (CS) : Nausea (US) → Illness (UR)– BUT…– AND…– Shouldn’t rats associate visual (location) cues with illness???3• Garcia & Koelling (1966)– Rats trained to drink water from tube– During drinking exposed to two types of CSs1.2.– Taste + Audio-Visual compound are CSs– Following conditioning• Half rats given dose lithium chloride →• Half rats given electric foot-shock →– Test• Half rats from each group rats allowed to drink flavoredwater• Half rats from each group allowed to drink plain waterpaired with audio-visual compound•Diagrammatic representation of Garcia & Koelling (1966)All rats learn to drink liquid from sipper tube – 2 CSs are presented•Flavored water = Taste CS•Light+Noise = Audiovisual CSEle ctric ShockLithium ChlorideLight & Noise (Audiovisual CS)Liquid is unflavoredLiquid is flavored (Ta ste CS)Light & Noise not presentedPre-trainingExposure to1 of 2 USsTest: number of licks in the presence of the 2 CSs4Results• Shocked rats– Drank very little whendrinking paired withaudio-visual CS– Drank more when tastewas only CS presentduring drinking• Poisoned rats– Drank very little whendrinking paired withtaste CS– Drank more whenaudio-visual CS waspresent during drinking10 020 030 0Licks Per MinuteUS TypeShockSicknessAudiovisualTastePreparedness & Pavlovian Conditioning• Results in opposition to equipotentiality hypothesis– Taste aversion– Fear more•Preparedness (Seligman, 1970)– Biologically determined tendency to more readilyassociate certain types of stimuli– Evolutionary relevance of prepared associations• Nausea more likely from ingested material• Pain more likely with stimulus that can be seen or heard– Prepared associations vs. non-prepared associations intaste aversion learning1.2.3.5Preparedness & fear conditioning• Fear-relevant CSs and aversive US are thought to beprepared associations1. Selective (Hugdahl & Öhman, 1977)2. One trial learning (Öhman, Erikson, Olofson, 1975)3. Resistant to extinction (Öhman, Erixon, Löftberg, 1976)4. Unaffected by cognitive influence???– Lipp & Edwards (2002)• Differential fear conditioning paradigm• Half Ps trained with pictures of• Half Ps trained with pictures of• Following acquisition, half Ps in each group instructed no moreshocks delivered; other half no instructions• DV = second interval GSR• Resistance toextinction– Fear-relevantnot instructedgroup vs. fear-irrelevant notinstructed group•Cognitiveinfluence– Fear-relevantinstructed groupvs. fear-relevantnot instructedgroupMean SIR (sqrt[uS])Mean SIR (sqrt[uS])Mean SIR (sqrt[uS])Mean SIR (sqrt[uS]) Fear-relevant/Instructed Fear-irrelevant/Instru cted Fear-relevant/Not Instructed Fear-irrelevant/Not Instructed Acquisition ExtinctionAcquisition ExtinctionAcquisition ExtinctionAcquisition Extinction6Preparedness & Pavlovian Conditioning• Fear-relevant CSs and aversive US are:1. Selective (Hugdahl & Öhman, 1977)2. Single trial learning (Öhman, Erikson, Olofson, 1975)3. Resistant to extinction (Öhman, Erixon, Löftberg, 1976)4. Unaffected by cognitive factors (Lipp & Edwards, 2002)5. Occur outside of awareness???• Öhman & Soares (1998)– Differential conditioning paradigm– Ps shown pictures of snakes & spiders OR flowers &mushrooms– CS+ always followed by shock; CS- never with shock– Pictures presented backward masked to prevent awareness• Example of backward masking7Öhman & Soares (1998) cont.• Results– Ps presented with snakes and spiders showeddifferential conditioning– Ps presented with flowers and mushrooms failed toshow conditioningPreparedness & Pavlovian Conditioning• Preparedness can explain why phobias are soeasily acquired– It makes sense that some CS-US associations arereadily learned– Selectivity – no sense in learning all CS-USassociations e.g.,– Rapid learning– Rapid detection– Genes find their way next into next generation• Preparedness can explain why phobias are sodifficult to treat– Fear to snakes & spider extinguishes more slowly– Despite safety instructions Ps still fearful8Preparedness & OperantConditioning• Evidence for biological constraints inoperant conditioningPreparedness & Operant Conditioning• Bolles (1970)–Animals cannot be trained to give any behaviorfor any reward• Rats can easily be trained to lever-press to receivefood rewards (they have evolved high level use oftheir paws to forage for food)• Rats cannot easily be trained to lever-press to escapeshock (natural reaction to fear is run or freeze)– Training difficulties can be explained byanimal’s evolutionary history9Preparedness & Operant Conditioning•Biological dispositions in pigeon avoidanceresponses– Pigeons can be easily trained to– Pigeons cannot easily be trained to peck a disk to avoidshock– Pigeons can be easily trained to flap their wings toescape an electric shock– Pigeons cannot easily be trained to flap their wings toget food• It seems that some behaviors are naturallyassociated with certain types of need•Bolles (1979)– Preparedness plays an important role in avoidance behavior– Avoidance responses not operants (controlled byconsequences) – seem to be elicited behaviors (controlledby stimuli that precede them)– Aversive stimuli elicit SSDRs (species-specific