0813 ENHANCING SLOW WAVE ACTIVITY VIA AN AUTOMATED PHASE LOCKED ACOUSTIC STIMULATION

Abstract

Introduction: Slow wave activity (SWA) is essential for cortical reorganisation and cognitive function. In healthy young adults, slow wave sleep (SWS) occupies ∼18% of TST, declining 2‐3%/decade, with a marked reduction in SW amplitude. Given the importance of SWA in maintaining optimal brain function, enhancing SWA is a clear target for improving cognitive function. Methods: Nine healthy adult men aged 35‐47 years participated in a randomized, double blind, cross‐over study involving two nights in the laboratory (baseline/night 1 + experimental/night 2) on two occasions, with at least one week in between. Participants wore an automated device delivering auditory tones phase locked to the slow wave to enhance slow wave activity during the STIM condition, but not in the SHAM condition. PVT was administered bi‐hourly and measures of executive function 2‐4 hours post habitual wake. Data were scored for SWS and power spectra in the delta (0.5‐4Hz) and slow oscillations (<1Hz). Results: Relative to SHAM, STIM significantly increased power spectra for both delta and slow oscillation frequencies, largely due to increased power spectra in the 3rd (slow oscillation) and 4th (delta & slow oscillation) SWS cycle. While this increase was observed over central derivations, this was most apparent at frontal sites. At the individual level, ∼80% of participants exhibited enhanced SWA, which ranged from a 5.1‐33.5% increase (in power spectra). Large effect sizes were observed for improved executive function (Verbal Fluency) and morning vigilance (PVT) following STIM relative to SHAM. Conclusion: Our preliminary data suggest an automated phase locked acoustic stimulation device significantly enhanced SWA in healthy middle‐aged men, with a clear improvement in cognitive function. Data collection and analyses are ongoing.