O072 Episodes of drowsiness present during cognitively demanding tasks

INTRODUCTION: Insufficient sleep is associated with impaired performance in cognitive tasks and executive functioning. Adolescence is a time of increasing autonomy and lifestyle changes, where social, educational, and work demands often impact on sleep opportunity. The impact of habitual short sleep opportunity on cognitive functioning is poorly understood. We examined the difference in EEG-based alertness during low and high load cognitive tasks in sleep restricted young adults. METHODS: Ninety-nine habitually sleep restricted young adults (M=20.65, SD=1.91, 73% female) participated in the study. EEG-based (F4-M1, O2-M1) alertness was examined under two conditions: (1) low load; a simulated slow drive and (2) high load; a weekly activity mapping task. A novel model predicted alertness as a continuous function of EEG power in beta, alpha, theta, and delta frequency bands. Model output 1 indicates alertness (i.e., wake), while values approaching zero indicate reductions in alertness. Statistical significance was assessed by two-tailed t-test (unequal variance), and effect size reported by Cohen’s D. RESULTS: Mean model output values were significantly (p<0.0001) lower during the driving task (0.16, 95%CI=0.12-0.19) compared to the mapping task (0.92, 0.87-0.97), with substantial effect size (D=3.9). CONCLUSIONS: This study demonstrates that sleep restricted young adults are less alert during tasks with low cognitive demands, even though the task we tested (simulated drive) represents high real-world risk. In contrast, these individuals show elevated levels of alertness during cognitively demanding tasks despite absence of real-world risk. Further study investigating potential mitigating effects through sleep modulation may reveal simple health recommendations