RecruitingClinical trialDose-Dependent Effects of Low-Intensity Focused UltrasoundLow-intensity focused ultrasound (LIFU) has emerged as a tool to modulate the activity of deep brain structures noninvasively and reversibly, with anatomical precision. Following the results of a pilot study in which the investigators observed target engagement when LIFU was applied to the anterior limb of the internal capsule, the investigators now propose to determine the dose-response relationships of LIFU when applied to deep white matter tracts of the human brain. The investigators hope a successful study will be rapidly translatable into clinical trials seeking to understand mechanistic brain circuit-symptom relationships in major psychiatric disorders.