[Eeglablist] EGI 256 to 128 channels ?

[Joseph Dien]

The EP Toolkit can remap from 256 to 128 using spatial interpolation (https://sourceforge.net/projects/erppcatoolkit)

Joe

> On Jul 19, 2017, at 18:56, Tarik S Bel-Bahar <tarikbelbahar at gmail.com> wrote:
> 
> Much appreciated Jeff, that should work as ideal solution. It's curious that no one seems to have done it yet. There are a few methodological articles out there that look at subsets of 256 and there relations to 10-5 and other location systems. Yes in my experience 128 to 32, and 64 to 32 is easier to do, and the 256 to 128 is more difficult.
> 
> EGI did not have a working solution/match comparing 128 and 256, but provides the 128 and 256 channel locations, placards, and 256/128 10-10 locations tech note.
> 
> In general, a manual solution is workable if one has the 128 and 256 placards (both on web and from egi support), and the EGI tech note on 10-10 locations of 256 and 128 channels. The placards are easily found googlable and at EGI's knowledge center, which includes the tech note named as below.
> relating-the-hcgsn-sensor-positions-to-the-10-10-international-electrode-placement-system
> 
> 
> 
> 
> 
> 
> On Mon, Jul 17, 2017 at 6:47 PM, K Jeffrey Eriksen <eriksenj at ohsu.edu <mailto:eriksenj at ohsu.edu>> wrote:
> My 2 cents worth:
> 
>  
> 
> Because of the geodesic (and in general spherical) layout of the electrodes, there is a very nice spatial down-sampling from 256 to 64, or from 128 to 32 (that is by a factor of 4). Going from 256 to 128 is problematic spatially. If possible I suggest spatially interpolating the 256 channel data to the exact 128 channel locations.
> 
>  
> 
> -Jeff Eriksen
> 
>  
> 
>  
> 
> From: eeglablist [mailto:eeglablist-bounces at sccn.ucsd.edu <mailto:eeglablist-bounces at sccn.ucsd.edu>] On Behalf Of Tarik S Bel-Bahar
> Sent: Sunday, July 16, 2017 2:19 PM
> To: eeglablist
> Cc: Support Team
> Subject: [Eeglablist] EGI 256 to 128 channels ?
> 
>  
> 
> Greetings,
> 
> Does anyone have (or know of) a list of which EGI 256 hydrocel channels
> 
> that match up with the EGI 128 hydrocel channels ?
> 
> We're basically looking for the best possible match,
> 
> and a list of which channels from the 256 layout to keep
> 
> in order to get as close as possible to the 128 channel layout.
> 
> Thanks very much for any info that is available!
> 
> PS. we are doing this somewhat manually/visually at this time,
> 
> and we already have access to the 10-10 correspondences tech note from EGI.
> 
> 
> 
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html <http://sccn.ucsd.edu/eeglab/eeglabmail.html>
> To unsubscribe, send an empty email to eeglablist-unsubscribe at sccn.ucsd.edu <mailto:eeglablist-unsubscribe at sccn.ucsd.edu>
> For digest mode, send an email with the subject "set digest mime" to eeglablist-request at sccn.ucsd.edu <mailto:eeglablist-request at sccn.ucsd.edu>
> 
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to eeglablist-request at sccn.ucsd.edu

--------------------------------------------------------------------------------

Joseph Dien, PhD
Senior Research Scientist
Maryland Neuroimaging Center
University of Maryland, College Park
http://joedien.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20170728/61278ccb/attachment.html>