TIMING BEHAVIOR AND CONDITIONED FEAR.

Rats were trained on a two-response timing procedure which required that response B follow response A by at least a minimum specified interval in order to be reinforced with food. Repeated presentation (5 min on, 5 min off) of an auditory warning stimulus terminated by a brief electric shock to the feet (conditioned fear) produced a marked suppression in the frequency of A-to-B response sequences during the warning stimulus. The distribution of A-to-B interresponse times (timing behavior), however, did not change during the warning stimulus.