Info for New Participants

Information for New Participants

The First Session

The first time you come for a Brain-Computer Interface session, we will talk about everything that will happen over the course of the testing procedure, which is also explained on this page. After the experiment is described and any questions are answered, you will sign a form indicating that you give your consent to participate in the research. Additionally, this form lets you know that no personal information will be provided to people outside of our lab; if we publish results in a paper, poster, or by other means, you will not be personally identifiable. After the consent form is filled out, you will complete a short questionnaire that provides us with some basic information about you, such as whether you are right or left handed, etc. After these papers are filled out, we will begin the test. I will either send you the correct forms to fill out ahead of time, or you will fill them out in the lab.

Experimental Setup

In the BCI experiments, we record your brain activity from the scalp, which is called an electroencephalogram, or EEG. Setting up the EEG is relatively straightforward, and takes about 20 minutes. To record the EEG, we place an elastic cap over your head, like a swim cap; each of the recording locations are in this cap, and wires transmit your brain signals to the computer. The image below shows a person with an EEG cap on.

Before putting the cap on, we attach a small clip-on electrode to your ear lobe, which is used for recording as well. After this, the EEG cap is slid over your head, and strapped below the chin with velcro straps. In order to get a good recording, we place some gel inside the electrodes so that there is an electrical connection between each electrode and your scalp. This is done by squirting the gel into the electrodes with a blunt-tip needle; the needle is then used to lightly abrade the scalp to remove any dead skin cells that can reduce the quality of the recording. This is generally not painful, although it may be briefly uncomfortable. Once all of the electrodes have been checked, we can start the experiment.

What You Will Be Doing

In these experiments, we teach people how to voluntarily change their brain activity in order to control a computer program. We do this by recording from electrodes over the parts of the brain that control movement, particularly the hands, arms, and feet. These locations are more or less the same for all people, as shown in this picture:

When you make a movement, such as clenching your hand, the EEG on the channels over your hand area change, which we can detect with the computer. Additionally, when you just THINK about that movement, the EEG changes in the same way. We can therefore teach you to imagine movements to change your EEG, which can be used for an application. In our lab, we translate these EEG changes into the movement of a cursor. During the basic BCI task, you will learn to move the cursor left, right, up, and down using motor imagery. The goal of the basic task is to move the cursor to a target on the computer screen within a short period of time. This process can take a while to learn, so we usually ask participants to come back for multiple sessions (at least 4). You can come back as many times as you like though!

Beyond the Basics

Once you are proficient at moving the cursor, then we can start doing the "real" experiments. This will involve moving the cursor to more targets, which might be smaller or further away, or moving the cursor both horizontally and vertically at the same time.