problems with 32 electrodes layout

dietcoke · Post by **dietcoke** » Sat Jan 08, 2011 6:43 pm

Hi all,

we have purchased a 32 A layout but realized that biosemi seems to take this 32 A layout from the 64 A+B layout. Thus, the recordings do not correspond to the actual electrode locations. As if the A layout has been directly taken from the A+B layout (we only have the A(oddsumbers) electrodes).

Moreover, some electrodes non-existant in the A layout (i.e., but do exist in the 64 layout) appear in the monopolar display, whikle others are absent. How can we set Biosemi to match with the 32 A layout only?

We also tried to manually select the electrodes (A1 to A32) using the freechoice, but the electrodes still dont match (ex. A4 = F1 in Biosemi, like in the 64 electrodes configuration. In our configuration, A4 should be F3).

I dont know if this could help you, but we re using a chidren cap...

any ideas how to solve this?

thanks a lot!

Alex[/i]

Post by **Coen** » Sun Jan 09, 2011 1:22 pm

Compare the layouts on http://www.biosemi.com/headcap.htm

If you want to do both 32 and 64 chan measurements, you should either relabel your caps and electrodes to ABC labeling, or you should purchase an extra dedicated A set for the the 32-chan measurements.

A 32-channel CFG is provided on the software CD and in the ActiView downloads on http://www.biosemi.com/download_actiview.htm

Best regards, Coen (BioSemi)

dietcoke · Post by **dietcoke** » Mon Jan 10, 2011 7:04 pm

Hi,

thanks a lot for your answer.

3 things:

-our team (but other team are using the same lab indeed) only wants to records with 32 electrodes

-we don t know how to relabel our caps annd electrodes. We must change manually the stickers or...?

-we dont want to buy another cap...unless its absolutely necessary!

thanks,

Alex