Applied Cognition Benchmarking Study

The study population will consist of healthy individuals, ages 55 to 65, that are cognitively normal and do not have a medical history of neurological or sleep disorder, cardiovascular disease, hypertension, or diabetes. The objectives of this study are to define whether sleep- and wake-associated device measurements (i) faithfully reflect glymphatic function measured by gold-standard contrast enhanced MRI and non-invasive MRI-based measures of glymphatic function; (ii) replicate pre-clinical findings between sleep EEG power bands and glymphatic flow; (iii) predict plasma levels of Alzheimer's disease (AD)-related biomarkers; and (iv) predict morning cognitive performance.

Inclusion criteria

• Participants must have a Montreal Cognitive Assessment (MoCA) score at least 26.
• Participants must have a Geriatric Depression Scale (GDS) 15-item score of 4 or less.

Exclusion criteria

• Participants with a formal diagnosis of any sleep disorder (e.g., sleep apnea on positive-airway-pressure (PAP) therapy, insomnia, restless leg syndrome, circadian rhythm sleep disorder, parasomnia).
• Participants with a history of significant neurological disease or history of epilepsy.
• Participants with cardiovascular disease or cardiovascular risk factors (smoking or hypertension).
• Participants with diabetes.
• Participants with traumatic brain injury, or serious mental illness including bipolar disorder, schizophrenia, major depressive disorder or post-traumatic stress disorder.
• Participants who have taken in the past 30 days prescribed or overthe- counter (OTC) stimulants, sleeping medications, or psychiatric medications including antidepressants.
• Participants who consume more than 400 mg/day of caffeine. Participants will be required to not consume caffeine beginning 12pm on the day-of the sleep study.
• Female Participants who consume more than 3 alcoholic drinks on any day or more than 7 drinks per week. Male participants who consume more than 4 alcoholic drinks on any day or more than 14 drinks per week.
• Participants planning travel to alternate time zones within two weeks of study participation
• Participants with travel plans or conflicts that would prevent them from either Study Visit.
• Participants who are enrolled in other research studies and are receiving an investigational drug within 30 days of the planned start date.
• Participants who have any condition that, in the opinion of the Sponsor Principal Investigator, would compromise the well-being of the participant or the study or prevent the participant from meeting or performing study requirements.
• Participants with absolute or relative contraindications to MRI imaging based on current up-to-date screening questionnaires including claustrophobia, inability to lie still on their back for 30-45 minutes or require sedation prior to the MRI.
• Participants with a head circumference greater than 60 cm that would prevent use of a high-resolution 64 channel MRI head coil required for this study
• Participants who have a pre-planned surgery or medical procedure that would interfere with the conduct of the study.
• Participants who have an implanted medical device or contraindications that would exclude MRIs
• Participants with a serious infection requiring medical attention in the past 30 days
• Participants with a diagnosis of substance use-disorder in the past 2 years.
• Participants with known acute or chronic kidney disease and/or compromised GFR.