⚗️Chapter 1: EEG Net Preparation

Part I. Measure Head Circumference [Session 2]

1. After the participant has completed all Session 2 tasks, guide them into the EEG area and seat them in the Polhemus chair.

2. Measure the circumference of the participant’s skull.

   • Acquire verbal consent to touch their head, i.e. “Is it cool if I touch your head?”

   • Start at the nasion (point between eyebrows directly above nose bridge) and wrap the measuring band once around the skull. Make sure that the band covers the inion in the back.

3. Note down the head size HERE (MURI Subject Database).

Part II. EEG Net Preparation [Session 3]

Begin preparing the appropriate sized EEG cap before the participant arrives. Allow it to soak until they arrive for their session.

ALWAYS HOLD THE CONNECTOR HIGHER THAN THE NET IN SEPARATE HANDS. Only the wire should hang freely. Do this to prevent any liquid from dripping down the wire to the connector.

1. Select the appropriate net size based on the circumfrence measurement (this should have been measured at the end of Session 2.

   • Small = 54-56cm, Medium = 56-58cm, Large = 58-61cm

   • Choose the larger net when between measurement is between sizes.

2. Prepare fresh electrolyte for each participant.

   Prepare fresh electrolyte for each participant.

3. Using the desinated measuring spoons, add and thoroughly mix the following in the electrolyte bucket:

   • 1 scoop potassium chloride crystals

   • 1 liter of water (fill to the 1 line on the bucket)

   • 1 scoop (5 ml) of Johnson & Johnson baby shampoo

4. Soak the net until the participant arrives for their session.

5. Remove the net. Shake off the excess liquid, and lightly dab the net with a towel.