To study modafinil-induced blood oxygenation level-dependent (BOLD) regional brain activity during working memory after 36 hours total sleep deprivation (SD).METHODS:Fourteen healthy young men participated in 36 hours sleep deprivation three times,3 weeks apart each.According to a randomized,double-blind self control cross-over design,subjects received modafinil,caffeine or placebo during each sleep deprivation period and completed visual working memory task after 36 hours sleep deprivation studied with functional magnetic resonance imaging (fMRI).RESULTS:The performance of working memory declined after 36 hours SD and restored by modafinil intake.Significantly increased activities of cortex of parietal lobe and prefrontal lobe,and decreased activities of anterior cingutate were found when subjects performed the verbal working memory task.