TRANSLATIONAL RESEARCH
IN AFFECT AND COGNITION
About EEG Research
Participant Guide to EEG: What happens at an EEG visit?
To learn more about the process of an EEG visit, check out this video from Vanderbilt University's MED Lab called "What Is EEG?"
This page is adapted from the University of Central Florida's BRaIN Lab and Vanderbilt University's MED Lab
Step 1: Welcome & Consent
A researcher will greet you and explain the study. You’ll then have a chance to ask questions about the study and sign a consent form.
Step 2: Preparation
You’ll sit in a chair while the researcher measures your head with a tape measure then applies a stretchy cap (which feels similar to a shower cap) with small holes for electrical sensors. Then, a small amount of nonreactive gel will be applied to the sensors with an applicator: this is painless and the gel can be washed off afterwards with water.
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Step 3: Tasks
This is the main part of the experiment, and will be different each time! For the tasks, you'll typically sit in a quiet booth in front of a desktop computer.
Step 4: EEG Recording
While you perform the task, the EEG will record your brain activity. The process is completely non-invasive and painless. We may remind you to sit still or relax during certain parts.
Step 5: Wrap-Up
Once the recording is done, the researcher remove the cap and clean up any leftover gel. While you can ask any questions you have during the experiment itself, at this point you can ask any final questions.
Participant Guide to EEG: How do I prepare for an EEG visit?
General Instructions:
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Hair: Arrive with clean and dry hair, with minimal product use. If it's raining outside on the day of your visit, try to keep your hair/scalp as dry as possible!
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Clothing: Wear comfortable clothes so that if we get a little gel on your shoulder, it'll be okay. Gel washes off of clothes and skin easily, but you might not want to wear your Sunday best in case it gets dirty.
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After the EEG: After your visit, you will have gel throughout your hair; gel washes out easily, but you may still want to wash your hair thoroughly before engaging in any other activities. We recommend deep conditioning after a lab visit, as the gel can be slightly drying.
Instructions by Hair Type:
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Straight/Wavy Hair (Types 1 and 2):
We recommend washing your hair the day before the lab visit.
Brush or comb your hair and scalp thoroughly the day of the lab visit, and arrive with your hair down or in a tight, low ponytail or bun.
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Low/Medium Density Curly Hair (Type 3a/b):
We recommend washing your hair 1-2 days before the EEG. On the day of the lab visit, we suggest detangling and styling into a braided crown, tight low buns, braided pigtails, or 2-strand twists. We may need you to loosen your hairstyle to help with the fit of the cap, but this is rare.
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High Density/Coily Hair (Type 3c and 4):
We recommend washing your hair 1-2 days before the EEG. We suggest detangling and styling into tight low buns, 2-strand twists, or flat cornrows. Try to split your hair down the middle to provide as much access to the scalp as possible, especially along the midline. We may need you to loosen your hair style in some places to help with the fit of the cap.
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Locs:
We recommend scheduling the lab visit right before a retwist. On the day of the lab visit and before the EEG, wet the roots of your hair and flatten slightly with a wrap while your hair dries. Be sure that your hair dries completely before the lab visit.
Straight or Wavy:
Hair down or low pony
Low Density Curls: Low, controlled styles
High Density Curls: Low, controlled styles
Locs:
Hair down, just before re-twist
Participant Guide to EEG: What is EEG research?
An electroencephalogram (EEG) is a non-invasive neuroimaging technique that researchers use to investigate your brain's response to different stimuli in the environment.
The Electrogram: The Product of an EEG
When a participant undergoes an EEG, sensors placed on the scalp measure fluctuations in the brain’s electrical activity, particularly in the brain regions closest to the surface (the cortex).
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The activity detected at each sensor is represented as a waveform known as an electrogram.
Electrograms are not unique to EEG: other bio-monitoring systems, such as electrocardiograms (ECGs) and electroretinograms (ERGs), similarly record the electrical activity of the heart and the retina, respectively.
Activity Level and Emotional Responses: What Researchers Learn from EEG Data
Sometimes, researchers use the frequency of an EEG waveform's oscillations to gauge a person's level of brain activity. Check out the waveforms to the right!
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Faster frequencies are classified as either Alpha or Beta waves, and are typically observed while a person is awake: Alpha waves are generally observed during periods of calm/sleepy wakefullness. Beta waves, in contrast, are usually seen during more energetic mental activity.
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Slower frequencies are either Theta or Delta waves, and are typically observed during sleep.
Alpha Waves:
Beta Waves:
Theta Waves:
Delta Waves:
Researchers also use EEG data to identify Event Related Potentials (ERPs), which are changes in the brain's electrical activity in following an event in the environment.
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At the TRAC Lab, for example, one of our primary research interests is how the brain processes rewarding events, like receiving food, money, or social acceptance. Check out the waveform to the left to see the Reward Positivity, a reward-related ERP that the TRAC Lab is currently investigating.