The SEAS Study: Sensory Engagement and Activation During Noninvasive Stimulation

Inclusion Criteria: * Able to provide written informed consent in English. * Willing and able to complete study procedures (e.g., \~1-hour sessions with non-invasive recordings, \~3-hour visit). Exclusion Criteria: * History of neurological disorders (e.g., epilepsy, migraines) or psychiatric conditions requiring medication. * Active implanted medical devices (e.g., pacemakers, cochlear implants) or metal in the neck/forearm that could interfere with stimulation or recordings. * Skin conditions or open wounds at stimulation sites (cervical neck, forearm). * Women who are pregnant or breastfeeding. * Current use of medications affecting autonomic or cortical function (e.g., beta-blockers, sedatives). * Inability to sit still for recordings or understand instructions (e.g., due to severe vision/hearing impairment).