The effect of intertrial conditioned stimuli in autoshaping

Three autoshaping experiments, using pigeon subjects, examined the effect of presenting an S+ or an S- on acquisition to a different conditioned stimulus (CS). Experiment 1 found that signalling intertrial food with an S+ or an S- allowed acquisition of responding to the target-CS; however, that acquisition was slower when the signal was the S+. Experiment 2 found that even when the S+ or S- were presented without food in the intertrial interval, acquisition was slower in the group receiving the S+. Experiment 3 found that a similar, but weaker effect occurred when the S+ or S- stimuli were presented in the session prior to target-CS training, rather than intermixed. These results have implications for the interpretation of experiments that use a signalling manipulation to assess the interaction of CS and context in Pavlovian conditioning; they suggest that signalling unconditioned stimuli (USs) may have consequences other than that of modulating context-US learning.     

Book reviews

Rajecki, D. W. (Ed.). Comparing behavior: Studying man studying animals. Hillsdale, N.J.: Lawrence Erlbaum Associates. 1983. IBSN 0-89859-259-3, Pp. 287, £22.95.