PSD of raw EEG recordings with VR headset

Support & Discussions
1

Hello,

We are designing a new EEG experiment in which participants need to wear a VR head mounted display.

During some pre-tests, we did several recordings:

  • EEG signals while a participant was wearing the headset unplugged,
  • EEG signals while the headset was plugged to the computer but not connected to the base stations (screen inside the headset was off)
  • EEG signals during the whole expriment: VR headset plugged and connected to base stations (a virtual environment was presented in the screen in the headset).

We computed and plotted the PSDs of the raw EEG signals. We obtained an unsual shape of the PSD for the signal during the whole experiment.

psd
psd1920×961 195 KB

However, PSDs of the EEG when the VR headset was unplugged, and plugged but disconnected from base stations (screen off) were ok.

psd_screen_off
psd_screen_off1920×977 164 KB

Has anybody already experienced such situation ?
We are using a Biosemi equipment for EEG recordings and a HTC vive pro 2 headset.

Thank you very much !

2

that does look weird. what does the continuous signal look like with the VR headset plugged in?

3

The second figure shows the PSD when the VR headset is plugged in but disconnected from the base stations.

4

yes, but that does the actual signal look like, not the PSD?

5

Could this be due to aliasing?