Delayed emergence of EEG-based task-relevant representations

This paper examines the effect of a period of quiet wakefulness (an “offline wake” state) on the performance of a decision making task. An initial feedback-based learning period using a subset of stimuli, was followed by (i) a “pre-test” phase using both “old” and “new” stimuli without feedback, (ii) a delay period of either active or offline wakefulness, and (iii) a “post-test” period, again without feedback. Behaviourally, we found that offline wakefulness significantly improved generalization — the ability to apply learned knowledge to novel stimuli. However, we did not find any EEG-based neural correlates of this generalization improvement. Rather, we found that task-relevant representations emerged only after the delay period, independently of whether the delay was active or offline.