Pupillometry and Locus Coeruleus Activation (PuLCA)

Inclusion Criteria: * Fluent English speaker with reading and writing proficiency. Exclusion Criteria: * Participants with significant visual impairment or ocular illness may be excluded at the discretion of the principal investigator. * Major medical illnesses including severe neurological illness (e.g. stroke, seizure history), autoimmune disorders, and severe psychiatric diseases (e.g., schizophrenia) * Any history of brain surgery, tumor, intracranial metal implantation, pacemakers, or other implanted devices. * Current (i.e. within 48 hours of the session) prescription medication or over-the-counter medication use. * Illicit alcohol or drug use. Caffeine (e.g, coffee, energy drinks) consumption prior to the visit.