Functional imaging of working memory following normal sleep and after 24 and 35 h of sleep deprivation: Correlations of fronto-parietal activation with performance.

Working memory was evaluated after normal sleep, and at 24 and 35 h of sleep deprivation (SD) in 26 healthy young adults to examine the neural correlates of inter-individual differences in performance. The extent of performance decline was not significantly different between the two SD test periods although there was greater variability in performance at SD35. In both SD sessions, there was reduced task-related activation (relative to normal sleep) in both superior parietal regions and the left thalamus. Activation of the left parietal and left frontal regions after normal sleep was negatively correlated with performance accuracy decline from normal sleep to SD24 thus differentiating persons who maintained working memory performance following SD from those who were vulnerable to its effects.