Begin by assembling the 16-channel EEG data acquisition system. Attach the Daisy module, which has eight EEG channels, to the board containing eight EEG channels. Using a Y-splitter cable, connect the reference electrode to the bottom reference pin on the Daisy board and the board both labeled as SRB.
Connect the ground electrode to the BIAS pin on the bottom board. Next, connect the 16 EEG electrodes to the bottom board pins and the Daisy bottom pins labeled N1P to N8P. Insert the electrodes on the gel-free cap at the labeled locations as per the international 10-20.
Soak 18 sponges provided for the EEG electrodes in a saline solution for 15 minutes. Insert the soaked sponges on the underside of each electrode to establish contact between the scalp and the electrode. Then, let the participant sit comfortably in a quiet room.
Place the gel-free EEG cap on the participant's scalp, and ensure the cap is aligned to fit over the participant's ears. Connect the USB dongle to the laptop, open the EEG GUI, click on EEG System. Under the Data Source option, select Serial 16 Channels, and Auto Connect.
Inside the data acquisition screen, select the signal widget to check the signal quality of the connected electrodes. At each electrode site, verify an optimal impedance level of less than 10 kiloohm. If the impedance is higher than 10 kiloohm, add a few drops of saline solution to the sponge under the electrode.
Then, close the GUI. Next, open the Acquisition Server software and select the appropriate EEG board under Driver. Click Connect and then Play to establish a connection with the EEG system.
For game design, open the Game Engine software and select Motor Imagery Training Project. Enable VR support by clicking on Edit, then Project Settings followed by XR Plug-In Management. Check the box for the VR headset listed under Virtual Reality SDKs.
Delete the default camera and drag the VR camera from the VR integration package into the scene. Also, place the imported animation file in the scene and adjust the scale and orientation as needed. For motor imagery training, set the OSC listener game object with pre-written scripts to trigger model animations for left and right-hand movements based on OSC messages.
Next, in the Game Engine software, open File and click on Build Settings. Select PC, Mac, and Linux standalone, then Target Windows followed by clicking Build And Run. For the motor imagery testing project, use the OSC listener game object configured with scripts to receive OSC signals indicative of the participant's imagined hand movements and make the avatar perform the imagined movement.
