The Role of Sleep in the Selective Reconsolidation of Declarative Memories
Abstract
While sleep has been shown to be involved in memory consolidation and the selective
enhancement of newly acquired memories of future relevance (Wilhelm, et al., 2011),
limited research has investigated the role of sleep or future relevance in processes of
memory reconsolidation. The current research employed a list-method directed forgetting
procedure in which participants learned two lists of syllable pairs on Night 1 and received
directed forgetting instructions on Night 2. On Night 2, one group (Labile; n = 15)
received a memory reactivation treatment consisting of reminders designed to return
memories of the learned lists to a labile state. A second group (Stable, n = 16) received
similar reminders designed to leave memories of the learned lists in their stable state. No
differences in forgetting were found across the two lists or groups. However, a negative
correlation between frontal delta (1 – 4 Hz) electroencephalographic (EEG) power during
Early Stage 2 non-rapid eye movement (NREM) sleep and forgetting of to-beremembered
material was found exclusively in the Labile group (r = -.61, p < .05).
Further, central theta (4 – 8 Hz ) EEG power during rapid eye movement (REM) sleep
was found to correlate with directed forgetting exclusively in the Labile group (r = .81, p
< .001) and total forgetting in the Stable group (r = .50, p < .05). These observed
relationships support the proposed hypothesis suggesting that sleep processes are
involved in the reconsolidation of labile memories, and that this reconsolidation may be
selective for memories of future relevance. A role for sleep in the beneficial reprocessing
of memories through the selective reconsolidation of labile memories in NREM sleep and
the weakening of memories in REM sleep is discussed.