Photography by Frank Miller

Participating in an EEG/ERP Study

ERP studies are quite different from most other Psychology studies that you may have participated in at Willamette. ERP technology allows us to record and monitor the electrical activity that is naturally occurring within your brain. We are essentially 'eavesdropping' on neural activity (though we can't in any way read your mind!), without taking anything out or putting anything in. Participating in an ERP study is safe and painless. Please let us know if you have questions or concerns regarding the safety or comfort of an experiment.

Prior to Testing Day

After signing up to participate in a study, you will be contacted by a lab member with more information about participation. We will also remind you of any exclusionary criteria for a particular study. For example, in most ERP studies, we are unable to include participants taking psychoactive medications (because this can affect the ERP signal in unknown ways). For our studies of neural systems for reading, we often can include only right-handed participants (because handedness affects lateralization). For some studies, you may be invited to a preliminary meeting so you can tour of the lab and ask any questions.

What to Expect on Testing Day

On the day of testing, you'll get a tour of the laboratory and, if you haven't already, be provided with a consent form to read and sign. For all ERP studies, the first 30 minutes or so will be devoted to applying an electrode cap so we can record brain activity. The electrode cap is made of fabric and fits similar to a swim cap. There are small plastic buttons on the cap that we can attach the electrodes to for recording. The electrodes never come in direct contact with your scalp. Instead, we use a little salt-based gel that helps the electrodes to pick up electrical activity at the surface of the scalp. The gel we use washes out in the shower like hair gel would, but you should expect to have some gel in your hair after participating. We also will place a few electrodes on your face that are attached with stickers. Removing these at the end of the experiment feels a bit like removing a BandAid. After capping you will begin the experiment. Typically, experiments last between 30min-1hr but this will depend on the specific experiment you are participating in. Prior to participating, a lab member will be able to give you a pretty good idea for the amount of time you should allot for participating in a specific experiment.

Reminders for Testing Day

  • Please come with clean and dry hair. If you have long thick hair you may want to bring a hair-tie to put your hair into a low ponytail.
  • If you wear contacts, we ask that you wear glasses for the experiment if possible. This can help reduce excessive blinking (as you'll see when you arrive, blinks produce a large signal that makes it hard to see the brainwaves!).
  • The testing room is kept relatively cool, as sweat interferes with the signal, so you may want to bring a light zip-up sweatshirt. Please make sure it is a zip-up sweatshirt not a pullover as it is difficult to remove a shirt once the electrode cap is on.