SKINNER’S “THEORY” OF INSTRUMENTAL CONDITIONING Two-term contingency: R  SR Nature of reinforcer can vary: R  S [SR, Sr, S-R, S-r]. 3-term contingency (Discriminative operant) SD : R  SR (light: bar press  food) S : R  SR (no light: bar press  food) Chaining of discriminative operants: Nature of discriminative stimulus can vary: [exteroceptive, interoceptive, proprioceptive].

SKINNER’S “THEORY” (con’t.) Contingency of reinforcement can vary: Rn/t  SR Schedule of reinforcement can vary: R  SR subject must emit n responses within a particular time frame t. Verbal Behavior. Behavior that is reinforced by a member of one’s verbal community. Private events. Discriminative responding to proprioceptive or interoceptive stimuli (stimuli under our skin, Sd : r  Sr)

Behaviorist Approach All learned behavior (human and animal) can be explained by the principles of classical and instrumental learning theory (2-factor learning theory). Classical conditioning: assumes that CS’s and US’s can be paired arbitrarily. assumes that temporal contiguity of CS and US is necessary and sufficient for establishing CR. Instrumental conditioning: assumes that responses selected for reinforcement are arbitrary. No need to postulate mental processes.

EVIDENCE THAT QUESTIONED BEHAVIORISTS’ ASSUMPTIONS “Misbehavior” of organisms Garcia’s experiment on taste aversion Autoshaping and omission training Blocking Rescorla’s experiment on predictiveness of US. Experiments on animal cognition Hunter’s definition of representation Radial maze Matching-to-sample

GARCIA EXPERIMENT ON TASTE AVERSION Rats signalled about two types of noxious stimuli (nausea and shock) by two types of CS (taste and sound). taste: liquid sweetened with saccharine nausea: induced by lithium chloride Group I: Compound CS [taste & sound]  Shock Group II: Compound CS [taste & sound]  Nausea Effect of CS evaluated in 2-bottle choice test: Bottle 1: saccharine flavored water Bottle 2: water Group I: preferred sweet drink (natural preference) Group II: preferred water (avoid natural preference)

Blocking experiment (Kamin) Training: CS1  Shock: CS1 + CS2  Shock Test: CS1  fear CS2  no fear

Predictable and Unpredictable Occurrences of Food _______ p ( F o o d /K ey Li gh t ) > p ( F o o d /K ey Li gh t ) P re d ic t a b le : Ke y L i g h t F oo d C S : U S : _______ p ( F o o d /K ey Li gh t ) = p ( F o o d /K ey Li gh t ) U n p re di cta bl e: C S : Ke y L i g h t F oo d U S :

Omission Training S D (Ke y l ig h t) : R ( Pe c k ) : S R (Fo o d) :

EVIDENCE THAT QUESTIONED BEHAVIORISTS’ ASSUMPTIONS “Misbehavior” of organisms Garcia’s experiment on taste aversion Autoshaping and omission training Blocking Rescorla’s experiment on predictiveness of US. Experiments on animal cognition Hunter’s definition of representation Radial maze Matching-to-sample

HUNTER ON “REPRESENTATIONS” ...If comparative psychology is to postulate a representative fact, ...it is necessary that the stimulus represented be absent at the moment of the response. If it is not absent, the reaction may be stated in sensory-motor term (Hunter, 1913, p. 21).

MATCHING-TO-SAMPLE A. Matching-to-Sample Peck

RADIAL MAZE