To begin, store the amplifier for the caregiver in the back pocket of the EEG cap to minimize cable movement and reduce EEG noise. Before applying the cap, check that the amplifier is securely stored and connected. With gloves on and after obtaining the caregiver's permission, clean the caregiver's forehead using alcohol swabs containing 70%isopropyl alcohol.
Part the hair on both sides at the top of the ear following the natural hairline to expose the caregiver's ear. To measure the caregiver's head circumference, place the measuring tape around the nasion over the crest of the inion and between left and right dragus. Now using a crown like hand gesture, stretch the EEG cap from the inside.
Start placing the cap from the caregiver's forehead towards the back of their head. Then hold the straps without releasing the cap. Pull them down towards the chin and fasten the hook and loop ends.
Remove any bangs or strands of hair from the caregiver's face to avoid discomfort or vision obstruction. Then smooth down the cap gently to ensure close contact of the electrodes with the scalp and to eliminate any wrinkles on the cap. Next, place the measuring tape over the electrodes at the midline and measure the distance from the nasion to the inion.
Adjust the cap using the scrunch and release method if necessary. Then measure the distance between the left and right dragus to ensure that the CZ electrode is at the midpoint of this measurement. Begin by applying gel to the reference and ground electrodes then proceed to gel the remaining electrodes starting with those at the back.
When applying gel to the caregiver, use a syringe with a longer, finer tip. Insert the syringe's tip into the electrode opening, and use the bottom curve to part the hair. Dispense small amounts of gel while withdrawing the syringe.
While applying gel to the passive infant cap electrodes, fill all electrode openings with gel and then use the cotton tips to part the hair in a gentle left to right motion. To improve electrode contact, use light as an impedance reference guide or refer to EEG recording software readings. After achieving low impedance on all EEG electrodes, clean the soft area under the participant's left collarbone with alcohol wipes.
Attach circular tape to the bottom of the ECG electrode and apply enough gel to cover the electrodes well. Place the electrode on the soft area under the left clavicle and secure it with white masking tape over the sensor.
