RELATIONSHIPS BETWEEN DISHABITUATION, SENSITIZATION, AND INHIBITION OF THE GILL-WITHDRAWAL AND SIPHON-WITHDRAWAL REFLEX IN APLYSIA-CALIFORNICA - EFFECTS OF RESPONSE MEASURE, TEST TIME, AND TRAINING STIMULUS

Previous studies have raised questions about the relationships between habituation, dishabituation, sensitization, and inhibition of reflex responses. To explore this issue further, a systematic study of these simple forms of learning was carried out in unrestrained Aplysia in wh ich the amplitude as well as the duration of both the gill-and siphon- withdrawal reflexes were measured after either tailshock or mantle sho ck. The results suggest that transient reflex inhibition is not an inv ariant effect of noxious stimulation but depends instead on the respon se measure, test time, and type of noxious stimulus. Furthermore, the results suggest that dishabituation and sensitization may not involve different processes at the behavioral level; rather the observed diffe rences between them may be due largely to an interaction between habit uation and inhibition.