Achievement

Evidence suggests that brain regions that have been disproportionately used during waking will require a greater intensity and/or duration of sleep. The parsimonious interpretation of findings is that sleep is distributed across local brain regions and is use-dependent. We have explored two physiological markers of local, use-dependent sleep: an electrical marker apparent as a change in the size and shape of an electrical evoked response, and a metabolic marker evident as an evoked change in blood volume and oxygenation delivered to activated tissue. Both markers provide a means to investigate physiological mechanisms for the distributed homeostatic regulation of sleep, and may yield insights into the consequences of sleep loss and sleep pathologies on waking brain function. We are designing a non-invasive method of monitoring this mechanism to study the effect of aging on sleep quality and its impacts on functional performance.