The Effect of Activity upon Learning and Retention in the Cockroach, Periplaneta americana

Abstract

The effect of activity upon retention and re-learning of avoidance responses to darkness was studied in the American cockroach, Periplaneta americana. Three degrees of activity were used: (a) forced activity on a treadmill, (b) normal resting activity, and (c) inactivity. Learning and re-learning were measured in terms of the number of trials required and shocks received in order to reach the criterion (9 avoidance responses in 10 trials). Intervals between learning and relearning from 10 min. to 24 hrs. were studied. It was found that forced activity affects relearning and retention adversely, and that the decrement was due chiefly to the physiological after-effects of activity. Relearning scores were considered to be determined by factor X (anti-consolidation) and factor Y (irritability). Factor X appears when activity follows learning closely, interfering with consolidation of the memory trace. Factor Y has its detrimental effect at the time of relearning. The sleep-like inactive state had a markedly beneficial effect on retention and relearning. The experimenters conclude that the superiority of retention and relearning after inactivity is chiefly due to a lack of irritability and the presence of no anti-consolidation factor.