0209 Examining the Role of Menstrual Phase on Sustained Attention Throughout Total Sleep Deprivation

Abstract Introduction Menstruation has been argued to affect the cognitive performance of women, but the available research is limited and its findings remain mixed. In this study, we investigated the effect of menstrual phase on one aspect of cognitive performance (i.e., sustained attention) throughout a period of total sleep deprivation (TSD). Methods A total of 31 healthy women (10 controls, mean age 27.6y ± 6.6y; 21 TSD, mean age 28.2y ± 5.9y) completed one of two highly controlled in-laboratory sleep studies each with a 38h TSD period or matching control condition with a 10h sleep opportunity. Performance was measured using a 10min version of the Psychomotor Vigilance Task (PVT). Test bouts administered at identical times in each study were used for analysis. Onset of menses and menstrual duration was determined using self-reported cycle length and regularity, most recent period, and next predicted period. The follicular phase was defined as the beginning of menstruation to the start of ovulation. Ovulation was defined as 14 days prior to the predicted date of the next period. The luteal phase was defined as the start of ovulation to the onset of menstruation. In our sample, 11 women were in the follicular phase, 9 were in the luteal phase, and 11 were menstruating. No women were in the ovulation phase during experimentation. Results There was a significant increase in both the number of lapses of attention (RT500ms) and mean reaction time in the TSD group (all F4.50, P 0.01). Performance on the PVT was not significantly affected by menstrual phase (all F 1.3, P0.30). Conclusion As expected, TSD degraded performance on the PVT as evidenced by an increase in the number of lapses and mean RT. Although we did not have any women in the ovulation phase during experimentation, it does not appear that menstrual phase impacted performance on a sustained attention task beyond the effects of TSD itself. Future research will examine the impact of menstrual phase on subjective ratings of sleepiness and cognitive tasks measuring other facets of cognition administered throughout TSD. Support (if any) ONR grant N00014-13-C-0063 and USAMRDC W81XWH-20-1-0442