The Neural Correspondences Associated With Sleep Deprivation In Waking Cognitive Performance Of Military Clearance Divers

PURPOSE: The aim of the present study was to investigate the effects of reduced sleep duration on Electroencephalogram (EEG) activity during cognitive performance tasks in Military Clearance Diver trainees, using a novel dry-electrode EEG system. METHODS: Using a repeated measures design, seven participants completed two 5-day periods of data collection separated into a baseline and a ‘live-in’ phase, with the ‘live-in’ phase comprising an increased workload and reduced sleep (5.4 ± 0.1 versus 7.4 ± 0.7 hours). EEG was recorded each day in separate groups of divers during early morning (AM) and late-afternoon (PM) during a Psychomotor Vigilance Test (PVT) and two oculography tests (AM: n = 4; PM: n = 3); EEG was also recorded each day (AM and PM) during two-minutes of eyes-closed. RESULTS: Significant increases were found during the PVT in the theta (t(29) = 2.308, p = 0.028, d = 0.421, CI = [0.528, 8.755]) and alpha (t(29) =2.124, p = 0.042, d = 0.388, CI = [0.144,7.852]) power spectrum densities (PSD) for the ‘live-in’ week compared to the baseline week. These results were in alignment with lower frequency bands increasing with time elapsed since waking, and thus, in parallel with sleep propensity. CONCLUSION: The present study demonstrates detectable modulation in waking neuronal activity using novel dry-electrode EEG technology, which may act to support characterizable fatigue-based markers for implementation within operational settings (e.g. military divers). This research project was funded by Ministry of Defence (UK) and managed by Defence Science Technology Laboratory (Dstl); it was contracted through the Human Social Science Research Capability (HSSRC).