Cortical Excitability

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.

When learning a new skill, much of the improvement comes from small alterations the brain makes with each repetition during practice, but this isn't the only time that improvements are made during the learning process. Individuals also get better at the motor skills during the time between practices, through a process called "consolidation." It is known that an area of the brain called the primary motor cortex is involved in learning during active practice, but the investigators want to study if the primary motor cortex is important for consolidation. The investigators will examine how lowering the activity in this brain region affects your ability to consolidate learning to play a song on the videogame Guitar Hero.

The purpose of this study is to evaluate tDCS combined with cognitive-motor training on dual-task interference during dual-task walking, dual-task foot pedaling and the corresponding alterations of brain activity.

This double-blind, randomized, sham-controlled clinical trial will evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on children and adolescents with attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) and matched healthy controls. Participants aged 6-19 years will be assigned to active or sham rTMS protocols targeting the dorsolateral prefrontal cortex over 3 weeks, with assessment of changes in disorder-specific symptoms and cortical excitability. The study aims to determine the safety, feasibility, and preliminary efficacy of rTMS as a non-invasive neuromodulation approach in pediatric neurodevelopmental disorders.