Speed/accuracy trade-off in the effects of acute total sleep deprivation on a sustained attention and response inhibition task.

Total sleep deprivation (TSD) is known to impair sustained attention. However, previously reported effects of TSD on response inhibition are mixed. We administered a "stop-signal" variation of the psychomotor vigilance test, which included 25% of trials requiring withholding of a response to assess response inhibition alongside sustained attention. Participants completed the task at baseline and after 34.5 h of wakefulness. Accuracy was not reduced during TSD. However, response times were significantly slower. A speed/accuracy trade-off allowed participants to effectively withhold responses on inhibition trials and conferred resilience of inhibitory control during TSD under conditions of relatively low time pressure.

DRD2 C957T genotype modulates the time-on-task effect during total sleep deprivation.

Total sleep deprivation (TSD) and time-on-task (TOT), especially in combination, increase cognitive instability and cause performance impairment. There are large inter-individual differences in TSD and TOT effects which, in part, have a genetic basis. Here, we show that the dopamine receptor D2 C957T genetic polymorphism predicts the magnitude of the TOT effect on a psychomotor vigilance test (PVT) during 38 h of TSD. This finding indicates that dopamine availability in the striatum, where the dopamine receptor D2 is most prevalent, influences the TOT effect, suggesting a role for dopaminergic pathways in sustained attention deficits during sleep loss.