Inclusion Criteria: All must be present  Age is 18 years or older Clinical suspicion of delirium or subject at risk for delirium Admitted to the Intensive Care Unit (ICU) Expected ICU stay is greater than one (1) day Subject must be fluent in English  Exclusion Criteria: All must be absent  Age is younger than 18 years Subjects with a primary neurological or neurosurgical condition such as stroke, epilepsy, brain tumor, or witnessed seizures, Parkinson's disease, traumatic brain injury, craniectomy, known severe dementia, or CNS infection Active CNS substance abuse, intoxication, or withdrawal Unarousable or unresponsive subjects with RASS < -3 Subject is blind, deaf, or unable to speak or understand English