Examination of Transcranial Focused Ultrasound on Brain Activity in Adults

The investigators will examine ventral striatum (VS) target engagement by tFUS in healthy adults using a reward processing task that reliably activates the VS.

Inclusion criteria

• No present/lifetime history of major depressive disorder (MDD), psychosis, Bipolar Disorder; Hamilton Depression Rating Scale (HDRS)>7; Young Mania Rating Scale (YMRS)>10), borderline personality disorder, and present suicidal ideation
• No family history of MDD, psychosis, Bipolar Disorder, or epilepsy

Exclusion criteria

• Present/lifetime history of MDD, psychosis, Bipolar Disorder (HDRS>7; YMRS>10), borderline personality disorder, and present suicidal ideation. Childhood history of, but not present, anxiety disorders and Attention-deficit/hyperactivity disorder (ADHD) will be allowed as these are common disorders in childhood
• Family history of MDD, psychosis, Bipolar Disorder, or epilepsy
• History of head injury, neurological (e.g., epilepsy), pervasive developmental disorder (e.g., autism), systemic medical disease and treatment (medical records, participant report)
• Use of substances with seizure risk (e.g., stimulants) in the past month, as for other non-invasive neuromodulation techniques, assessed as screening and before each tFUS session
• Mini-Mental State Examination (MMSE) score (cognitive state) <24
• Premorbid North American Adult Reading Test (NAART) intelligence quotient (IQ) estimate <85;
• Visual disturbance: <20/40 (Snellen visual acuity)
• Left/mixed handedness (Annett criteria)
• History of alcohol or other substance use disorder (SUD), daily nicotine use, and/or illicit substance use over the last 3 months (SCID-5). Note: lifetime/present cannabis use (<3 times in the past month) at non-SUD levels will be allowed, given its common usage in young adults. Urine tests on scan days will exclude current illicit substance use. Salivary alcohol tests on scan days will exclude intoxicated individuals
• Binge drinking (as defined by National Institute on Alcohol Abuse and Alcoholism (NIAA) criteria: consuming 5 or more drinks (male), or 4 or more drinks (female), in about 2 hours.) in the week before, and/or >3 drinks/day for the 3 days before, and/or alcohol in the last 12 hrs before, any alcohol on tFUS scan day, confirmed at screening and scan days. Alcohol/nicotine/caffeine/cannabis use (below SCID-5 SUD and binge levels) will be allowed
• MRI exclusion criteria: metallic objects, e.g., surgical implants; claustrophobia; positive pregnancy test for females or self-report pregnancy
• Unable to understand English
• Taking any psychotropic medications in the past 3 months
• Any implanted neural device
• Color blind