The purpose of this study is to explore whether a non-invasive form of ear stimulation called transcutaneous auricular vagus nerve stimulation (taVNS) can change the way you perceive pain. We will recruit up to 20 participants with chronic post-stroke upper extremity pain. The goal is to determine if there is a pain reduction after ear stimulation.

The purpose of this study is to explore whether stimulating different outer parts of the ear using a non-invasive form of ear stimulation called transcutaneous auricular vagus nerve stimulation (taVNS) will create different brain activation images. We will recruit 24 healthy participants. The ear stimulation will be delivered while taking brain images using a magnetic resonance imaging (MRI) machine.

The aim of this study is to use magnetic resonance imaging (MRI) to capture images of participants' brains and apply an image processing method called INSCAPE to assess brain states. This study will recruit participants who are scheduled to receive accelerated Transcranial Magnetic Stimulation (TMS) therapy for Major Depressive Disorder (MDD). Participation in this study involves two visits, each including a 30-minute MRI scan. The interval between each visit is about one week. Depressed participants will also complete mood assessments at various intervals while they are receiving accelerated TMS for depression.