The supportive role sleep performs for maintaining optimal cognitive performance

Sleep is one of many pillars of cognitive health, as it performs vital functions for maintaining optimal cognitive performance. In a major role, sleep sustains and prepares the ideal neurophysiological conditions for cognitive functions the following day. This is obvious given the drastic effects that sleep deprivation has on cognitive performance, however the processes for how sleep performs this vital function are still unclear. In this presentation I will describe studies using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) that investigate the neural correlates of cognitive impairments due to sleep deprivation. By leveraging a bidirectional design of sleep deprivation and recovery sleep (Cross et al. 2021a), we are able to propose a neurophysiological model for how sleep loss may impair effective communication within the brain via altering the balance of integration and segregation of functional brain networks (Cross et al. 2021b). This imbalance can be observed through dynamic functional connectivity and will be discussed in the context of autonomic and other physiological (e.g. cardiovascular) mechanisms. The role of the BOLD global signal in this context will also be addressed. Finally, this presentation will describe ways in which these neurophysiological patterns can be used to not only understand cognitive processes, but how to leverage this knowledge in clinical research to gain important insight into sleep disorders such as central hypersomnolence (eg. narcolepsy) and their debilitating behavioural symptoms.