TMS

This study is investigating how two types of non-invasive brain stimulation, transcranial electrical stimulation (TES) and transcranial magnetic stimulation (TMS), affect brain activity, and whether combining them produces stronger or more consistent effects than either one used alone. The motivation for this comes from the observation that TMS, which is FDA-approved for treating depression, tends to work less well in postmenopausal women because lower estrogen levels reduce the brain's ability to respond to stimulation. The research team believes that pairing TMS with TES, which targets a different set of brain cells, may be able to overcome this hormonal barrier and make stimulation more effective. Participants will come into the lab for up to 24 visits over 8 months, beginning with an initial visit to establish the right stimulation settings, followed by a series of stimulation sessions in which brain activity is measured before and after receiving either TES, TMS, or both together. For female participants, sessions will be scheduled at specific points in the menstrual cycle to capture the natural monthly rise and fall of estrogen, while male participants will be scheduled on a comparable fixed interval as a comparison group. The insights gained from this study could directly inform the development of better, more reliable brain stimulation treatments for women with depression.

Stroke is a major cause of long-term disability, with cognitive and motor deficits-especially action slowing and executive dysfunction-being strong predictors of poor recovery outcomes. Recent advances in network neuroscience suggest that action speed is governed by interactions between specific prefrontal and premotor regions. However, the precise neural mechanisms underlying action slowing in stroke remain unclear, limiting the efficacy of current rehabilitation approaches. This study integrates high-density EEG, fNIRS and dynamic causal modeling (DCM), and rTMS to map and modulate the neural circuits involved in action speed. In the first phase, we will assess the role of seven key brain regions in action speed modulation by applying virtual lesions using single-pulse TMS in 60 healthy individuals. In the second phase, we will apply offline intermittent theta burst stimulation (iTBS) to the most relevant regions and evaluate its impact on action speed. Finally, in the clinical phase, we will administer individualized iTBS to 20 stroke patients to enhance action speed. Patients will be assessed at baseline, immediately post-treatment, and after one and three months to track improvements in action speed using DCM and behavioral tests. Changes in connectivity and action speed performance will be compared to healthy controls to refine treatment parameters. Secondary outcomes include executive function and daily life motor performance. Longitudinal follow-up will determine the persistence of improvements, informing future personalized rehabilitation strategies. By characterizing effective connectivity changes post-stroke, we aim to refine neuromodulation strategies and develop a personalized rTMS approach. Our hypothesis is that targeting specific regions identified through integration of EEG, fNIRS and DCM can enhance action speed, ultimately improving functional recovery. This personalized approach could lead to more effective rehabilitation protocols, tailored to individual brain damage patterns.