[Eeglablist] EGI 256 to 128 channels ?

[Tarik S Bel-Bahar]

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-internation
al-electrode-placement-system






On Mon, Jul 17, 2017 at 6:47 PM, K Jeffrey Eriksen <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] *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
> To unsubscribe, send an empty email to eeglablist-unsubscribe at sccn.uc
> sd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20170719/eddd6b38/attachment.html>