Influence of sleep homeostasis and circadian rhythm on executive discriminative ability during a constant routine

Introduction & Objectives
The human brain upholds cognitive performance throughout a waking day due to putative circadian (C) arousal signal which counteracts the increase in homeostatic (H) sleep pressure associated to the deterioration in brain efficiency. When wakefulness is extended into the circadian night, maintenance of cognitive performance is jeopardized . Some individuals are very vulnerable to the negative effects of sleep loss and circadian misalignment, whereas others are resilient. These individuals differences can be readily explained within the conceptual framework of the circadian and homeostatic regulation of performance but also by individual genetic differences and notably the PERIOD3 gene polymorphism.
In this experiment, we investigated the consequences of sleep deprivation on cognitive performance during a working memory task (3-back). Following the signal detection theory, the ability to discriminate target from non-target stimuli is estimated by d prime (d') and criterion (cr). Here we assessed whether d' and cr were modulated by the raising sleep need and the oscillatory circadian signal. We also tested whether the individual vulnerability to sleep loss predicted by the PERIOD3 gene polymorphism influences this cognitive modulation, which is also driven by the sleep/wake regulation.