0170 Trial-to-Trial inconsistency in Reaction Time on the Psychomotor Vigilance Test Alters Self-Reported Sleepiness

Abstract

Daytime sleepiness is associated with impaired attention processes, including slower and more variable reaction time. Although results are mixed, recent research has started to show the positive association between insomnia severity, greater daytime sleepiness and impaired simple attention processes. In this study, we aimed to determine whether performance on an attention task influences self-reported sleepiness of individuals across the sleep disturbance spectrum. Participants (N=50) included individuals across the insomnia spectrum from good sleepers to patients with insomnia disorder. Insomnia severity was assessed using the Insomnia Severity Index. Simple attention was assessed using a computerized Psychomotor Vigilance Test (PC-PVT) administered in the morning. Participants’ rated their sleepiness on a scale from 1 (not sleepy) to 10 (extremely sleepy) before and after they completed the PVT. Spearman’s correlation coefficient was used to assess associations between insomnia severity, sleepiness, and PVT performance. Multiple regression was used to determine whether mean or trial-to-trial variability in reaction time predicted post-PVT sleepiness, adjusting for pre-PVT sleepiness and Insomnia Severity Index score. Greater trial-to-trial variability in PVT reaction time predicted greater post-PVT sleepiness after adjusting for pre-PVT sleepiness and insomnia severity, t=2.9, p=0.005. Insomnia symptom severity was associated with greater sleepiness at pre- and post-PVT, rs (50)=0.41, p=0.003 for both. After adjusting for pre-PVT sleepiness, insomnia severity was not a significant predictor of post-PVT sleepiness. Average PVT reaction time was not associated with sleepiness. Participants with greater inconsistency in simple attention performance reported greater sleepiness than they had reported 10 minutes previously. Trial-to-trial variability in reaction time performance may have raised participants’ awareness of their sleepiness. Alternatively, participants with inconsistent performance may have altered their self-report to match their performance. Although insomnia symptom severity was associated with sleepiness it did not make participants more prone to biased sleepiness reports based on performance on the PVT. N/A