Auditory Closed-Loop Stimulation of the Sleep Slow Oscillation Enhances Memory

SummaryBrain rhythms regulate information processing in different states to enable learning and memory formation. The <1 Hz sleep slow oscillation hallmarks slow-wave sleep and is critical to memory consolidation. Here we show in sleeping humans that auditory stimulation in phase with the ongoing rhythmic occurrence of slow oscillation up states profoundly enhances the slow oscillation rhythm, phase-coupled spindle activity, and, consequently, the consolidation of declarative memory. Stimulation out of phase with the ongoing slow oscillation rhythm remained ineffective. Closed-loop in-phase stimulation provides a straight-forward tool to enhance sleep rhythms and their functional efficacy.Video Abstract To view the video inline, enable JavaScript on your browser. However, you can download and view the video by clicking on the icon belowHelp with MP4 filesOptionsDownload video (74257 K)

► Sounds in phase with slow oscillations enhance brain slow oscillatory activity. ► In-phase stimulation enhances spindle activity phase coupled to slow oscillations. ► In-phase stimulation promotes sleep-dependent memory consolidation. ► Closed-loop stimulation provides a new tool for probing the function of EEG rhythms