A mainstay in the diagnosis and care of hospitalized patients is the assessment of mental status. Changes in mental status can have broad clinical significance, and while some patients are admitted with mental status changes, nearly half of the patients who experience delirium in the hospital develop it after admission in a manner that is hard to predict on the level of individual patients. Patients with altered mental status such as delirium have worse clinical outcomes, suggesting that early monitoring of mental status can identify important clinical populations who may benefit from targeted delirium prevention and intervention. Delirium remains under-recognized in the hospital, in part due to its fluctuating nature. Typically, mental status is assessed sporadically, perhaps once a day, through intermittent and subjective clinical interactions. As such, there is a clear clinical need for objective, continuous methods to monitor mental status. Such methods could potentially improve detection of delirium, potentially even predicting it prior to clinical recognition, and therefore direct multimodal delirium prevention and intervention strategies when most effective-before delirium becomes fully manifest. In this proposal we plan on testing noninvasive, continuous monitors of mental status in the inpatient setting, primarily through the use of EEG.

Inclusion Criteria:

• Admitted to a general medical ward
• Expected stay of at least one night

Exclusion Criteria:

• patients who have any scalp incisions or head wound(s) that would prevent EEG attachment
• Non-English speakers

Patients will be recruited after their admission to inpatient medical units at the participating hospital.