The role of sleep in explicit memory processes from the aspects of emotional salience

Abstract

The aim of our study was to investigate the effect of sleep and emotional salience in explicit memory processes. Thirty-four students participated in the experiment in two groups: in a sleep group and in a wake-group. We used word-pair task to assess explicit memory performance that contained emotionally negative, positive and neutral word pairs in an equivalent rate. There were two sessions for both group: Learning Phase and Testing Phase separated by 12 hours’ offline period with sleep for the sleep-group and 12 hours awake period for the wake-group. We revealed that the sleep-group demonstrated better performance from evening to morning compared with the wake-group caused by that the wake-group showed higher forgetting rate on the explicit task. Furthermore, we found higher improvement in the emotionally negative and neutral words in the sleep-group. These findings suggest that sleep facilitates the explicit memory consolidation, especially the emotional memory processes.