Bio 281 2011 Lecture 3 - Learning - Lecture Notes Small

Learning Learning and reinforcement Learning A long-lasting change in behavior, or potential to change behavior, that results from experience Reinforcement Anything that affects the probability that a particular behavior will occur Simple learning Habituation and sensitization Aplysia Habituation Sensitization Percent birds responding Repeated presentation of stimulus chaffinch Playbacks Classical conditioning Eric Kandel Classical conditioning Is there any adaptive significance of classical conditioning? food (US) salivation (UR) food (US) + tone (CS) salivation (UR) tone (CS) salivation (CR) Ivan Pavlov 1 Classical conditioning Classical conditioning ♀ ♂ blue gourami Karen Hollis Mount Holyoke Classical conditioning Classical conditioning How might classical conditioning work in nature? Courtship behavior by female (US) Courtship (UR) Courtship behavior by female (US) + sex-recognition cue (CS) Courtship (UR) Sex-recognition cue (CS) Courtship (CR) Heritability of conditioned response Japanese quail Gene × environment interactions Proboscis extension response conditioned to various odors Offspring score Evidence of significant heritability Tryon Maze Dull and Bright rats Parent score 2 Operant conditioning Laws of effect and exercise Thorndike Operant conditioning Operant conditioning = association between behavior and its consequences Operant conditioning Positive reinforcement Negative reinforcement Increase likelihood that behavior will occur B.F. Skinner Operant conditioning Response cost “Punishment” What factors affect conditioning? 1. Contiguity 2. Relevance Decrease likelihood that behavior will occur John Garcia 3 The “Garcia effect” The “Garcia effect” Practical applications of the Garcia effect Schedules of reinforcement 1. 2. 3. 4. Operant conditioning Fixed (also continuous) Variable Ratio schedules Interval schedules What produces the characteristic “scalloping” effect in the FI schedule? Operant conditioning Learning sets Trials 1-5 Block 1 A B A B A B A B A B A B A B Trials 1-5 Block 2 A Why the “stair-step” pattern? B A B A B Where should monkey look first? Now where should monkey look? rhesus macaque 4 Learning sets Latent learning Development of generalized learning strategy Reinforcement not evident Wisconsin general test apparatus Percent correct Harry Harlow (1905-1981) Rhesus macaque Domestic cat Gray squirrel Number of problems solved Latent learning Latent learning Tinbergen observed beewolf’s circular flight as it departed burrow Wolfgang Kohler Insight learning Learning by applying previous knowledge Social learning Local enhancement: presence attracts others Social facilitation: presence facilitates learning 5 Social learning Social learning Two groups of cows conditioned to avoid larkspur by pairing with LiCl Copying versus imitation Reinforced in one group, extinct in the other Both paired with naïve cows Larkspur consumed Extinction cows Reinforcement cows Social learning Mate choice copying Mate choice copying in guppies Alternative explanations? A1: Focal female wants to school with groups of fish. focal ♀ ♀ ♀ ♀ model here or here ♂ ♀ focal ♀ Focal female chose male near model 17 of 20 times ♀ ♂ Replaced end males with females, and focal female showed no preference for 2 fish vs. 1 fish (10 of 20 trials) model here or here Mate choice copying Social learning Alternative explanations? A1: Focal female cues on behavior or physiological changes of chosen male. Why copy mate choice of others? Classic example in humans = Bandura’s “Bobo” experiments ♂ new focal ♀ ♂ Removed focal and model female, replaced with new female. She had no preference for primed male. May allow less discriminating, younger animals to make better choices 6 Social learning Teaching Can be vertical or horizontal A working definition of teaching Sex differences in tool-use imitation in chimpanzees Tandem running in Temnothorax ants Teaching Teaching prey capture Meerkats present toxic prey to young R = distance of antennal reach Teaching prey capture Groups with young pups Experimental playback of pup begging calls Groups with old pups 7