ABSTRACT
Sleep promotes memory consolidation through unique neuromodulatory activity. However, little is known about the impact of attention during pre-sleep memory encoding on later memory performance. The current study aimed to address the question of whether attentional state prior to encoding, as indexed by alpha oscillatory activity, modulates the consolidation of images across periods of sleep and wake. 22 participants aged 18 – 41 years (mean age = 27.3) viewed 120 emotionally valenced images (positive, negative, neutral) before a 2hr afternoon sleep opportunity and an equivalent period of wake. Following the sleep and wake conditions, participants were required to distinguish between 120 previously seen (target) images and 120 new (distractor) images. Relative alpha power – adjusted according to participants’ individual alpha frequency — was computed to index attentional state prior to the learning phase. Generalised linear mixed effects modelling revealed memory performance was modulated by attention, such that greater pre-encoding alpha synchronisation promoted memory consolidation after wake, but not sleep. There was no difference in memory performance between positive, negative and neutral stimuli. Modulations in alpha oscillatory activity may help coordinate the flow of information between task-relevant cortical regions and a thalamo-cortical loop that subserves the formation of memory during times of wake but not sleep.