BLOCKING OF SUBSEQUENT AND ANTECEDENT EVENTS

Stimulus competition (e.g., blocking) has been observed between antece dent events (i.e., conditioned stimuli or potential causes), but recen t evidence within the human causal learning literature suggests that i t could also be obtained between subsequent events (i.e., unconditione d stimuli or potential effects). The present research tested this hypo thesis with rat subjects. To avoid confounding the antecedent versus s ubsequent variable with the affective value of the events involved (i. e., unconditioned stimuli are ordinarily of greater affective value th an conditioned stimuli), a preparation was used in which antecedent an d subsequent events all lacked affective value during the blocking pha ses of the study. This was achieved through the use of sensory precond itioning. Blocking of subsequent events as well as antecedent events w as observed. The challenge to most associative theories that is provid ed by blocking of subsequent events is discussed.