What do the electrodes look like?

Here are some basic pictures to give you an idea.

Three silver electrodes are connected to a special EEG amplifier. After being placed on the head, the electrodes will detect very tiny electrical signals generated by the brain and send them to the EEG amplifier. Signals are millionths of a volts (microvolts) at the scalp. The EEG amplifier must take that signal, multiple it, and send it to the computer where it’s interpreted and displayed by special software.

We prefer using the best possible amplifier since the amplifier is responsible for the integrity of the signal. Like a radio trying to tune in to a far away station, the more accurately and sensitively that signal is read and amplified, the clearer the information the brain will receive about itself.

Notice the yellow electrode now has paste. That’s a flat electrode. It will be placed directly at a site on the head. The wax or paste is electrically conductive.

The ear clips (like earrings) are placed on the ear lobe. They also must use the same electrically conductive paste. The paste allows the tiny electrical signal to be more easily read.

Rather than having 2 ear clips and 1 flat electrode, you can also have 1 ear clip and 2 electrodes on the head. Either of those combinations make up one EEG channel.

This is the flat electrode with paste about to be placed at C4  on the right side of head.

We always recommend that the site be prepped by scrubbing it with an abrasive such as Nu-Prep prior to sticking the electrode on the scalp. That helps minimize any noise from getting into the feedback.

We also recommend: When the electrode is placed, a measurement be made to ensure a quality connection.

Here’s the ear clip with paste about to be placed. We recommend the ears also be prepped with an abrasive to ensure a consistent signal and connection.

Here’s an electrode placed a little higher than C4. The other end is connected to the amplifier. In this case, there’s not too much hair to worry about. In most cases, the placement needs to be made carefully, so there’s not much hair underneath the electrode. It needs a good connection with the skin. Even with the thickest hair, it is still possible to get a good connection.