MS 302.qxp

Study Objective: To examine whether differences in patterns of brain activation under baseline conditions relate to the differences in sleepdeprivation vulnerability. Design: Using blood oxygenation level dependent (BOLD) functional magnetic resonance imaging, we scanned 33 healthy young men while they performed the Sternberg working memory task following a normal night of sleep and again following 30 hours of sleep deprivation. From this initial group, based on their Sternberg working memory task performance, we found 10 subjects resilient to sleep deprivation (sleep deprivationresilient group) and then selected 10 ageand education-matched subjects vulnerable to sleep deprivation (sleep deprivation-vulnerable group). Setting: Inpatient General Clinical Research Center and outpatient functional magnetic resonance imaging center. Patients or Participants: Data from 10 young men (mean age 27.8 ± 1.7 years) in the sleep deprivation-resilient group and 10 young men (mean age 28.2 ± 1.9 years) in the sleep deprivation-vulnerable group were included in the final analyses. Interventions: None. Measurements and Results: We compared functional magnetic resonance imaging BOLD signal at rested baseline and sleep deprivation states in the 2 groups. As hypothesized, following sleep deprivation, both groups showed significant decreases in global brain activation compared to their rested group baseline. At rested baseline and in the sleep-deprivation state, the sleep deprivation-resilient group had significantly more brain activation than did the sleep deprivation-vulnerable group. There were also differences in functional circuits within and between groups in response to sleep deprivation. Conclusions: These preliminary data suggest that patterns of brain activation during the Sternberg working memory task at the rested baseline and the sleep-deprivation state, differ across individuals as a function of their sleep-deprivation vulnerability.