Inclusion Criteria:  Inclusion criteria:  Age 25-65 years, with age range matching our past sleep and MRI protocols in AUD; encompassing the young-middle age range for adults, allowing at least a 5 year drinking history for AUD and outside of adolescence (younger cut-off) and before substantial age-related impact on sleep and health (older cut-off); Male, female; At least 8 years of education; Meet cut-off criteria on cognitive tests (MoCA, > 23, WTAR,> 85)104,105,126 Meet clinical DSM 5 criteria for alcohol use disorder with at least a 5 year drinking history (AUD group) or not meet clinical DSM 5 criteria for any psychiatric disorder (Control group). Be at least 6 months abstinent, up to 36 months abstinent, based on 2,13,35 showing that REM sleep excess is evident  Exclusion Criteria:  History of medical or neurological illness or trauma that would affect the central nervous system (e.g., stroke, multiple sclerosis, epilepsy) History of loss of consciousness over 30 min, compound skull fracture or clear neurological sequelae; Greater than mild past other substance use disorder and/or current other substance use disorder not in remission (< 1 year since meeting criteria) (AUD only) Current post-traumatic stress disorder and/or generalized anxiety disorder; Current clinical diagnosis of moderate-severe substance use disorder (other than alcohol) History of schizophrenia or bipolar disorder; Current severe medical conditions (e.g. uncontrolled Diabetes, chemotherapy for cancer); Current use of benzodiazepine, hypnotic, or anti-depressant medications; Shift work in the six months prior to the study; Moderate-severe sleep-disordered breathing (apnea-hypopnea index 15 or greater at the clinical PSG); Periodic Limb Movements (PLM) Disorder with a PLM arousal index greater than 10 events per hour at the clinical PSG; Pregnant; Current use of drugs or alcohol at clinical visits (positive drug screen or breathalyzer > 0); MRI contraindications, such as: irremovable metal implements, cardiac pacemakers, claustrophobia, excessive body size compromising placement in scanner; Corrected visual acuity of less than 20/40 as assessed by the Snellen Visual Acuity chart  Age limits: 25-65 years