To begin, assign participant IDs and ask participants to wash and dry their hair within one hour before participating in the experiment. Mix the electrolyte gel and abrasive electrolyte gel in a one-to-three ratio, adding a small amount of water. Stir the mixture evenly in a container with a spoon.
Prepare fine-tipped cotton swabs and a dry EEG cap. Now ask the participant to sit comfortably in a chair and inform them that the experimenter will apply the EEG cap. Provide the participant with instructions about the experimental tasks and an informed consent form for the experiment.
Obtain the participant's signature before proceeding with the preparation phase. Next, connect the EEG cap to the amplifier, which in turn connects to the EEG data acquisition computer. Use an additional monitor to check the color indicators on the 64 electrodes, as this study uses a passive cap.
Open BrainVision Recorder and import a customized workspace file that has defined the recording parameters. Click on Monitor to check the impedance. Ask the participant to sit upright in a chair.
Select an appropriately sized gel-based passive electrode system for the participant's head. Now dip a disposable cotton swab into the conductive paste and apply it to the holes of the cap, making sure to rub against the participant's scalp. An electrode's corresponding indicator turning green on the EEG data collection computer signifies that it is successfully collecting optimal data.
Once the indicative color for all electrodes on the screen except for the two independent sided electrodes turn green, apply the side electrodes to attach the left electrode near the participant's left eye and the right electrode near the right temple. Once all electrodes are green, place an elastic net over the participant's head to help the EEG cap fit more securely and stably against the participant's head. Then equip the participant with wired headphones.
Close the electromagnetic shielding door and guide the participant's actions through a microphone that allows communication inside and outside. Additionally, monitor the participant's movements through an external monitor, reminding them not to move their body significantly. Also, monitor the participant's progress in behavioral tasks through a behavioral data monitor.
Ask the participant to wear earphones connected to the behavioral collection computer through an audio interface.
