PS261 Lecture Notes - Lecture 10: Classical Conditioning, Reinforcement
Document Summary
Discrete trials: escape trials, avoidance trials. Two mechanisms: classical conditioning pair cs and us, negative reinforcement response terminate the cs, avoidance through fear reduction, these t(cid:449)o (cid:272)a(cid:374)"t exist o(cid:374) their o(cid:449)(cid:374) It"s the a(cid:271)se(cid:374)(cid:272)e of fear, (cid:374)ot the a(cid:271)se(cid:374)(cid:272)e of sho(cid:272)k that is the (cid:373)oti(cid:448)ator. Fear: we are predisposed to learn about it! Escape from fear experiments: first do classical conditioning separate tone with shock only no escape, then do instrumental conditioning with tone only no shock. Independent measurement of fear during acquisition of avoidance behaviour: the more you are able to avoid, your fear goes down, problem for two-process theory. Extinction of avoidance through response-blocking and cs-alone exposure. Free-operant avoidance avoidance without a warning signal: s-s (shock-shock) interval, r-s (response-shock) interval, also challenges 2-process theory, no cs to elicit fear, temporal cues, varied intervals. Positive reinforcement: safety signals provide positive reinforcement, shock-frequency reduction.
