Most studies on consciousness focus on being conscious (or aware) of a particular thing, as opposed to being not conscious of it. Fewer studies focus on being conscious (or awake) as opposed to being unconscious. The former is easier to study, but the latter is just as important for understanding this foundational concept.

The aim of this project, directed by Melanie Boly at the University of Wisconsin, is to investigate the neural mechanisms of what makes us conscious as opposed to unconscious. It will focus on the transition between these states, in particular, loss of consciousness during sleep.

Previous studies in this field have used high-density EEG which can only provide relatively indirect evidence for the contribution of specific brain areas to consciousness. This project will use direct intracranial recordings in humans, which is a technique that is more difficult to carry out, but it provides much more detail. The aim is to establish which brain regions have the greatest change in activity during loss of consciousness, during both non-rapid eye movement (NREM) sleep and REM sleep.

The project will seek volunteer test subjects from a cohort of epileptic patients who undergo (as part of their medical treatment) sleep recordings and serial awakenings during 6-10 consecutive nights during their clinical stay at the epilepsy monitoring unit. The research team will collect subjective reports of the presence or absence of consciousness after 250 awakenings from sleep (from 20 patients) then compare slow-wave activity topographies during dreaming vs loss of consciousness.

If successful, the results will provide strong evidence to support or challenge different theories that emphasize the role of anterior vs. posterior cortical areas in consciousness. This research is expected to lead to several publications in high-impact neuroscience journals and to presentation in international conferences. The findings could lead to innovative neuromodulation therapies to prevent or revert loss of consciousness during seizures and other disorders of consciousness, and impact ethical decisions concerning withdrawal of care in unresponsive patients with severe brain damage.