fig4

Figure 4. PMA sponge electrodes integrated on a VR headset for EEG recording; (A) Placement of sponge electrodes on a VR headset, with Fp2 at a hairless site and Cz and Oz at hairy sites; (B) The complete setup for EEG recording in which commercial cables are clipped on the FCA terminals; (C) Alpha bandpass filtered EEG signals (8-12 Hz) captured during eye-close and eye-open periods from one subject, with similar results for three other participants; (D) Time-frequency analysis of the EEG signals recorded at Oz, showing event-related spectral perturbation (ERSP) as a ratio of average amplitudes in the experimental condition (eyes-close or eye-open) to baseline epoch (taken from the start of the recording before subject instructions were given). In (C) and (D), shaded areas indicate eye-closed periods; (E) PSD of the EEG signals recorded at Oz during eye-close (blue) and eye-open (red) conditions; (F) Comparison of the EEG signals recorded by the sponge electrode and the solid gel electrode at comparable locations (Fp2 and Fp1, respectively) after bandpass filtering (1.5-50 Hz); (G) Comparison of EEG signals recorded by the sponge electrode (Cz) and a commercial comb electrode (OpenBCI) located adjacent to it. EEG: electroencephalography; PMA: poly (3,4-ethylenedioxythiophene) polystyrene sulfate/melamine; VR: virtual reality.