Memory impairments observed after a half night sleep restriction are not mediated by working memory, attention, or inhibitory control mechanisms

Sleep restriction is a growing issue in our modern society and thus it is crucial to uncover its neurocognitive consequences. Especially declarative memory is negatively affected by sleep loss due to its critical dependence on the hippocampus, a brain area known to be susceptible to sleep loss. Studies have shown that even a half night sleep restriction is sufficient to induce impairments in a range of hippocampus-dependent forms of memory. Nevertheless, memory performance is, at least to some extent, dependent on other cognitive functions. The aim of the current study was to reveal whether memory deficits observed after one night sleep deprivation, as observed in animal studies, translate to man, and whether these effects are mediated by impairments in other cognitive domains. We hypothesized that the memory paradigms would be affected but that, due to the short nature of the sleep restriction, this effect would not be mediated by other cognitive functions. To this end, fifty-five healthy participants conducted a test battery containing paradigms measuring verbal learning, spatial memory, attention, working memory, and response inhibition after a night of regular sleep or acute partial sleep restriction. The results of the study showed an impairment in both hippocampus-dependent memory tests, while no negative consequences of sleep deprivation were revealed on the other cognitive domains. In conclusion, our data indicate that the observed deficit in memory performance after a half night sleep deprivation is not mediated by impairments in attention (alerting, orienting, and executive control), working memory, or motor inhibitory control mechanisms.