0214 Paradoxical Effect of Stimulus Density on PVT Time-on-Task Effect during Sleep Deprivation. (27th April 2018)

• Record Type: Journal Article
• Authors: Honn, K A; Van Dongen, H
• Is Part Of: Sleep. Volume 41(2018)Supplement 1
• Page Start: A84
• Page End: A84
• Publication Date: 2018-04-27
• Subjects: Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsy061.213
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Introduction: The 10min psychomotor vigilance test (PVT), which requires responding as fast as possible to stimuli presented at random inter-stimulus intervals (ISIs) of 2s-10s, is highly sensitive to vigilant attention deficits due to total sleep deprivation (TSD). The deficits are evident in increased response times (RTs) during task performance, which are amplified by time on task. However, it is not clear what aspect of performing the PVT drives the time-on-task effect. One perspective is that cognitive load associated with the relatively high density of stimuli in the PVT is responsible for its sensitivity to sleep loss and the time-on-task effect. It would thus be expected that increasing the stimulus density should amplify the time-on-task effect. We tested this prediction in a laboratory TSD study comparing the standard task (PVT) to a higher stimulus density version with ISIs of 2s-5s (HD-PVT). Methods: N=18 subjects (ages 21–37, 14 females) took the HD-PVT at 18:00 after 34h awake, flanked by the standard PVT at 17:00 and 19:00. RTs per 1min bin were analyzed using mixed-effects linear regression to compare the slope of the time-on-task effect between test sessions. Results: RTs showed significant interaction of test session by slope (F2, 6086 =4.16, p =0.016), with a smaller time-on-task effect in the HD-PVT at 18:00 as compared to the standard PVTs at 17:00 (t6086 =1.73, p =0.083) and 19:00 (t6086 =2.79, p =0.005). Conclusion: Contrary to expectation, increasing the stimulus density in the 10min PVT did not increase the time-on-task effect, but rather reduced it. This suggests that cognitive load associated with responding to stimuli is not what determines the PVT's sensitivity to sleep loss and the magnitude of the time-on-task effect. Instead, the durations of periods between trials, when response inhibition is required, may be the primary contributor to PVT impairment and the time-on-task effect during sleep deprivation. Support (If Any): CDMRP grant W81XWH-16-1-0319.