Record 32 or 64 channels with 128 channel cap

magnuson · Post by **magnuson** » Sat May 15, 2010 1:09 am

Are there maps available for ideal electrode placement if we are only going to record from 32 or 64 channels with 128-channel caps?

Thanks,

jim

Post by **Coen** » Mon May 17, 2010 11:43 am

The 32 and 64 layouts in 10/20 style are not subsets of the 128 layout (see http://www.biosemi.com/download/Cap_coords_all.xls ). We recommend to purchase 32 and 64 caps with ABC labeling.

Best regards, Coen (BioSemi)

magnuson · Post by **magnuson** » Mon May 17, 2010 11:55 am

We would if we could, but we don't have the funds for new caps right now. Has anyone worked out the approximations?

Thanks,

jim

Post by **Coen** » Mon May 17, 2010 12:17 pm

The coordinate file (128-chan worksheet, column D) provides 22 positions that coincide between 128 and 64 channel layouts. The remaining positions can be approximated by comparing the coordinates.

Best regards, Coen