How to add positions of 64 EEG Channels of g.tec?

Hi All,

I’m working with 64 Channel EEG data captured by g.tec cap, and I have a problem regarding adding EEG positions. I see based on the number of channels for some caps such as ANT, BioSim, BrainProducts, and NeuroScan; there are some available EEG channel position mapping for the default head model. However, this feature is not available for g.tec. Nonetheless, I can add their positions using Generic, ASA 10-20 94. As this position mapping is related to 94 channels and I have 64 channels from a different model (but the same system of positioning of 10-20), I’m doubtful that my source localization would be accurate. However, those 64 channels have been appropriately recognized (with their own name), and their positions on the head look good. So, I was wondering if you could let me know am I allowed to use Generic, ASA 10-20 94 for g.tec 64 or not.

Thank you.

If the g.tec caps respect the 10-10 or 10-20 convention, you should be able to use the default positions in the "Generic" menu, indeed. This is actually why this standard (10-10/10-20) was adopted in the EEG community, it ensures that an electrode label (eg. Cz or P3) refer to the same position on the scalp across people and across devices.

I can't help you validate this statement with you g.tec caps, but this is something you could easily check yourself - or ask the g.tec customer support about what they think about their compliance to these standards.

Keep in mind that when working with EEG and template heads, electrode placements and source locations have to be interpreted as loose approximations. Do not expect a precision below 1-2 cm.

Thank you very much, Francois.