0085 Vulnerability to Sleep Restriction is Associated with Decreased Working Memory Performance

Abstract

Abstract Introduction We investigated whether individuals with more lapses on the psychomotor vigilance task (PVT) after sleep restriction (SR) demonstrated poorer working memory compared to those with fewer PVT lapses. Methods Fifteen healthy men (22.3±2.8 years) participated in a 10-night inpatient protocol with three nights of 10-hour baseline time in bed (TIB), five nights of SR (5-hour TIB), then two recovery (10-hour TIB) nights. Participants completed the Visual Object Learning Task (VOLT) and Fractal 2-Back (F2B; visual n-back) measuring working memory and the PVT (Joggle Research® battery) approximately every two hours during wake. During the VOLT, participants indicated whether presented images had been shown previously. Outcomes included number of misses and false alarms. During the F2B, participants tapped the screen when an image appeared that had been shown 2 images previously. Outcomes included sensitivity and specificity. Median split of mean PVT lapses after the last night of SR was used to categorize participants into “vulnerable” (n=8) versus “resistant” (n=7) groups. Outcomes were analyzed in mixed models with the predictor day*vulnerability, excluding the first three baseline days to preclude practice effects. Results There was a significant interaction between day and attentional vulnerability for VOLT misses (p<.001); misses increased linearly across days in vulnerable (b=.18, p<.001) but not resistant (p=.956) participants. There was no interaction between day and vulnerability for VOLT false alarms, which did not change across days. There was a significant interaction between day and attentional vulnerability for F2B sensitivity (p=.002); sensitivity increased linearly across days in resistant (b=.02, p<.001) but not in vulnerable (p=.273) participants. There was no interaction between day and vulnerability for F2B specificity, which did not change across days. Conclusion Performance on the VOLT decreased in vulnerable participants only; performance on the F2B improved in resistant participants likely due to practice effects not seen in vulnerable participants. Findings indicate vulnerability to attentional lapses after SR is a marker of vulnerability to working memory decrements. Support This study was funded by grant UL1TR000127 from the Clinical and Translational Science Institute (Chang PI) and the College of Health and Human Development at the Pennsylvania State University.