The effects of sleep deprivation (SD) on the neural substrates of inhibition control are poorly understood. Here we used functional magnetic resonance imaging to examine the effects of 24 h of SD on cerebral activation during a stop-signal task in 20 normal young subjects. Behaviorally, subjects showed significantly delayed stop-signal reaction time (SSRT) following SD. In addition, reduced cerebral activation was found in the "stopping network" (including the inferior frontal gyrus [IFG], supplementary motor area, subthalamic nucleus [STN] and insula) and vision-related regions (occipital cortex, lingual gyrus and fusiform gyrus) after SD. These findings support the hypothesis that task-related activation in prefrontal cortex is particularly vulnerable to SD. After rested wakefulness (RW), significant negative correlations were found between SSRT and cerebral activation in left IFG, right hippocampus, right lingual gyrus, left STN and bilateral fusiform gyrus, with activation in left IFG making the most contribution. After SD, significant negative correlations were found between SSRT and activation in right middle frontal cortex, right IFG and left lingual gyrus, with the activation in right IFG making the most contribution. Furthermore, we observed significant interaction effects of state (SD or RW) with activation in bilateral IFG, left STN and left lingual gyrus on SSRT. In conclusion, sleep deprivation is associated with the deficits in inhibition-related neural activation and the altered correlation between SSRT and cerebral activation, especially in the bilateral IFG, left STN and left lingual gyrus.
Keywords: Inferior frontal gyrus; Response inhibition; Sleep deprivation; Stop-signal task; fMRI.