TMS involves sending magnetic fields into a person’s brain to stimulate nerve cells. Using TMS to stimulate the brain and measure brain activity is not currently FDA-approved for healthy people and is considered experimental.

Before testing, we will place electrodes on the skin of your hands. These electrodes will record muscle activity from your hands. A device called a coil will rest on your head, as shown here in the picture. We will send an electric current through the coil to create a magnetic field. The magnetic field will pass through your skin and skull and into your brain. You will not feel the magnetic field, and it will not hurt or damage your body. During this part of the experiment, you will hear a click, and it may feel like someone has lightly tapped your head. We will determine the intensity of stimulation needed for you; this is because everyone’s brain is different.

You will be seated in a chair with your arms placed in molded hand rests during the experiment. We will place one coil over the part of your brain called the motor cortex. We will place a second coil over a different part of your brain involved in planning voluntary hand movements. During the TMS procedure, you will experience slight twitching and muscle contractions in your arm and hand. During stimulation, we will measure your hand muscle activity through the electrodes. We will use TMS to study the excitability of the two parts of your brain and how different regions of your brain send commands to your hand muscles.