Florida State University
This is a non-invasive brain stimulation and neuroimaging study that will examine how activity in the medial prefrontal cortex influences reward processing, particularly positive savoring, in individuals with depression. The central question is whether modulating medial prefrontal brain regions using transcranial magnetic stimulation (TMS) alters neural and behavioral responses to rewards. Brain activity will be recorded using both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) while participants perform reward tasks. The primary objectives are to (1) identify patterns of brain activity linked to impaired reward processing in depression using EEG and fMRI, and (2) determine the causal role of specific prefrontal areas in these processes through targeted TMS. The methods include four sessions over four weeks: a clinical assessment, EEG recording during reward tasks after participants learn/practice positive savoring, an fMRI session, and a TMS session combined with EEG while participants practice positive savoring and perform reward tasks during EEG.
Inclusion Criteria: * Between the ages of 18 and 65 * Able to provide informed consent * Have normal or corrected vision * Right handed * Willing to comply with all study procedures and be available for the duration of the study * Speak and understand English * Not color blind * Acceptable suicide risk as determined by less than 5 on the Depression Symptom Index Suicidality Subscale (DSI-SS) * A diagnosis of major depressive disorder (current episode) on the Structured Clinical Interview for the DSM-5 (SCID-5) * Between the ages of 18 and 65 Exclusion Criteria: * ADHD (currently under treat…
For accelerated intermittent theta burst stimulation (aiTBS), stimulation intensity will be set at 80% resting motor threshold (rMT), a level that has been established to be safe and effective. aiTBS will consist of bursts containing 3 pulses at 50 Hz. Bursts will be delivered at 5 Hz for 2 seconds at 80% of rMT, followed by 8 seconds without stimulation. This pattern will continue for 60 cycles (1800 pulses), for a total elapsed time of 10 minutes. Participants will be randomized to receive aiTBS to their mPFC, dlPFC, or primary somatosensory cortex (S1) a total of two times in a single session for 10 minutes each (spaced 50 minutes apart) before/after EEG preparation and practicing a positive affect technique (i.e., savoring), and before performing a positive savoring and reward responsivity task during EEG.