Timing matters: open‐loop stimulation does not improve overnight consolidation of word pairs in humans. (10th August 2016)

• Record Type: Journal Article
• Authors: Weigenand, Arne; Mölle, Matthias; Werner, Friederike; Martinetz, Thomas; Marshall, Lisa
• Editors: Molholm, Sophie
• Is Part Of: European journal of neuroscience. Volume 44:Number 6(2016:Sep.)
• Page Start: 2357
• Page End: 2368
• Publication Date: 2016-08-10
• Subjects: memory -- sleep -- slow oscillations -- spindles -- thalamocortical system; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.13334
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: The application of auditory clicks during non‐rapid eye movement (NREM) sleep phase‐locked to the up state of the slow oscillation (closed‐loop stimulation) has previously been shown to enhance the consolidation of declarative memories. We designed and applied sequences of three clicks during deep NREM sleep to achieve a quasi‐phase‐dependent open‐loop stimulation. This stimulation was successful in eliciting slow oscillation power in the stimulation period. Although fast and slow spindle power were markedly decreased during the stimulation period, memory consolidation did not differ from control. During putative up states fast spindle power remained, however, at control levels. We conclude that concurrence of slow oscillations and fast spindles suffices to maintain memory consolidation at control levels despite an overall decreased spindle activity. Abstract : Auditory clicks applied phase‐locked to the up state of the slow oscillation (closed‐loop stimulation) during NREM sleep have previously been shown to enhance the consolidation of declarative memories, slow oscillation and spindle power. Here, sequences of three clicks were applied to achieve a quasi‐phase‐dependent open‐loop stimulation. Stimulation successfully elicited slow oscillations, but spindle power decreased in the stimulation period. Memory consolidation did not differ from control.