0222 A NAP HAS NO EFFECT ON THE TRANSITIVE INFERENCE TASK

Abstract

In the Transitive Inference (TI) task, subjects are given premise pairs of the form A > B, B > C, etc., and intuit the relationships between items not previously seen together (i.e. A?C). Previous studies have reported that in subjects trained to below-ceiling levels on the premise pairs, the passage of time affects performance on the TI task, and that sleep specifically boosts performance on 2º pairs-pairs of items linked by 2 intermediate items (A?D). Healthy subjects (18–30 yrs) were trained on the premise pairs of a six-item hierarchy of abstract visual stimuli. During learning subjects guessed, with feedback, which item to choose out of a pair, until they reached 70% accuracy. Later they were tested on pairs of items not seen together during training. In Experiment 1, subjects were tested only once, after 3 hours, or twice, after 20 minutes and 3 hours. In Experiment 2, all subjects were tested at both 20 minutes and 3 hours; some subjects napped between tests. In Experiment 1, there was no evidence that testing at 20 minutes affected performance at 3 hours, justifying the repeated measures approach of Experiment 2. In Experiment 2, performance at 3 hours did not differ significantly between subjects who did or did not nap. On average, there were no changes in performance on this task over the course of 3 hours, with or without sleep. In contrast to previous work, many subjects had high levels of performance after only 20 minutes, especially on 2º pairs. In contrast to how previous work on the effect of delay and sleep on the TI task has been done, changes in performance should be measured within-subject. Previously reported differences between performance at 20 minutes and later, or between performance after sleep and after wake, may have been due to cohort differences. Alternatively time and sleep dependent changes may take longer than 3 hr to develop. MH48832, TR000170.