Brain Oxygenation Marker for Cognitive Function in Healthy Adults

Inclusion Criteria: 1. Males and Females 25-45 years old 2. BMI between 18.5 kg/m2 and 29.9 kg/m2 3. Conditions for study procedure compliance: * Willing and able to sign an informed consent form * Be fluent in English (self-reported C1 or C2 English level) * Be able to provide a cortical oxygenation signal (based on feasibility to fix the measurement device on the scalp, which can be altered by hair thickness) * Be dominant right-handed * Have a normal or corrected-to-normal vision * Be expected to comply with the protocol Exclusion Criteria: The project exclusion criteria are: 1. Conditions that may affect cortical oxygenation: * Be insomniac (insomnia severity index, ISI, higher than 15 based on rating at the medical screening) or night shift worker (based on anamnesis) * Be currently diagnosed with migraine (based on anamnesis) * Be currently diagnosed with hypo- or hyper-tension (based on evaluation of BP measure against medical norms at the medical screening) * Have an historical or current neural, cerebrovascular, cardiovascular, or respiratory disease (based on anamnesis) * Have a heavy usual consumption of caffeine-based beverages i.e., more than 5 servings of caffeinated coffee/colas or tea or 1 serving of caffeinated energy drinks per day * Be a regular smoker (regularly defined as greater than 2 cigarettes per week) * Participate in a vigorous physical activity requiring more than 6 metabolic equivalents e.g., hiking, jogging at 10 km/h or more, carrying of heavy loads, bicycling fast at 23 km/h or more, basketball, soccer, and tennis single, greater than 4 times 45 minutes per week 2. Conditions that may affect cognition or the mental fatigue * Take illicit drugs (for e.g., cannabis, heroin, and cocaine) * Have an average alcohol consumption greater than 2 standard drinks per day over a week for males, and greater than 1 standard drink per day over a week for females. One standard drink contains 10-12 g of ethanol. Examples of standard drinks are one beer can (300 ml), one glass of wine (100 ml) or one glass of schnaps (30 ml). * Have a psychiatric disorder or be currently diagnosed with anxiety or depression * Be pregnant (verified by a pregnancy test in urine dipstick format) or seeking to become pregnant or breast feeding 3. Have a hierarchal or family relationship with any of the research team members. 4. Currently participating in another interventional study.