State anxiety moderates memory benefits of wakeful rest: Greatest inhibition of offline consolidation at moderate anxiety levels

Brief periods of offline wakeful rest following learning reliably enhance declarative memory consolidation and retention compared to online cognitively demanding post-encoding tasks. The influence of individual differences, including affective states, on this process remains under-researched, but emerging evidence suggests that trait anxiety may play a moderating role in rest effects on memory. The contribution of state anxiety - during both offline and online states - to awake consolidation remains to be established. The present study investigated whether state anxiety during post-learning wakeful rest and task engagement influences declarative memory consolidation. In a counterbalanced repeated-measures design, adults with no clinical presentation of anxiety encoded wordlists followed by either a wakeful rest period or an active task. State anxiety was measured during each post-encoding condition using a standardised self-report scale, and delayed recognition was used to assess memory retention via a signal detection approach. As expected, hit rates were modestly higher following wakeful rest than task engagement although overall recognition sensitivity (d') did not differ significantly. Crucially, hit rates and d' scores following wakeful rest varied non-linearly with state anxiety: moderate anxiety impaired memory, whereas low and high anxiety preserved it. No such non-linear relationship was observed for false alarm rates or for any memory outcomes in the task engagement condition, and contrary to previous research, trait anxiety did not influence memory. These findings suggest that while wakeful rest supports awake consolidation, the internal affective state - specifically moderate levels of anxiety - may disrupt the mental processes conducive to early memory stabilisation.