cPAS-fMRI

Study Purpose: To use neuroimaging and behavioral metrics to track the impact of repetitive multi-focal stimulation on the parietal-frontal network involved in motor control over multiple days. 

Who is eligible: Healthy, right-handed, English-speaking adults between the ages of 18 and 50 years with no history of neurological disorder can take part in this study. 

What to expect: Up to 15 sessions, including an initial 2-hour screening and behavioral and neurophysiological measures. During week 1, there is an initial 2-hour fMRI session, followed by five 1-hour sessions of TMS (electrical brain stimulation), and a final 2-hour fMRI session. Stimulation weeks are separated by an interval of at least 4 weeks, then week 2 follows the same schedule as week 1. 

Time commitment: Over the course of 2 weeks, participants will undergo 1 week of full-intensity stimulation and 1 week of sham stimulation, separated by at least 4 weeks. 

Compensation: Up to $500.

Recruitment status: Recruiting soon!

IRBMED HUM00257788Date of approval: 09/01/2024

What are TMS and tDCS?

Transcranial magnetic stimulation (TMS) and Transcranial direct current stimulation (tDCS) are both forms of non-invasive brain stimulation (NIBS). This process is considered non-invasive because it does not involve placing anything under your skin or inside your body. 


TMS

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. 

tDCS

tDCS involves sending a weak electrical current through the brain via electrodes attached to the scalp. The tDCS device used in this study has not received FDA approval and is limited to investigational use in the US.

 

We will apply tDCS using a battery-operated stimulator delivered through a pair of saline soaked surface sponge electrodes or gelled electrodes placed in holes of a neoprene cap (see picture) for ~20 minutes. You might feel a slight itch under the electrode.  This is normal, and it will not hurt or damage your body. During the tDCS procedure, you likely will experience a tingling sensation on the scalp where electrodes are attached; this tingling sensation usually diminishes after several seconds. The goal of the tDCS portion of our study is to determine the roles of brain regions used to control hand movement, by measuring behavior and brain activity during stimulation.

 

When we remove the electrodes, a small amount of gel may remain in your hair; this generally comes out easily with water and shampoo.


Brain Behavior Lab

Kinesiology Building

Parking 

at the Kinesiology Building

Functional MRI Laboratory

Bonisteel Building