[Eeglablist] Spatial resolution

[Arnaud Delorme]

Spatial resolution also depends on the number of channels given to ICA.
In the mixing matrix, the contribution of one component (representing a 
brain EEG source) is a linear mixture of the potential at all 
electrodes. As a consequence, the more the electrodes, the more accurate 
the contribution of the component will be. This is especially true for 
local EEG sources that do not project to many electrodes on the scalp.
Spatial resolution of the localization of the components in the brain 
then depends on the accuracy of the dipole/or finite element software.

Arno

Lars O.D. Christensen wrote:

>Hi,
>
>I am trying to understand ICA and its possible applications. It's very
>interesting.
>
>One issue of importance for me is what the best spatial resolution one
>can obtain is, that is, e.g. in terms of anatomical distances how well
>can sources be separated (how close together can the sources be before
>they simply overlap/merge, if ever ...) ? A related question would, for
>example, be whether it is possible with ICA to separate sensory input to
>S1 from its effect on M1 (motor cortex) since these areas are clearly
>distinguisable (by the central sulcus) but anyway only separated by a
>few centimeters, or maybe only millimeters (at most).
>
>If anybody could tell me something about this, please do.
>
>Best regards,
>Lars
>  
>


-- 

*Arnaud Delorme, Ph.D.*
Computational Neurobiology Lab, Salk Institute
10010 North Torrey Pines Road
La Jolla, CA 92037 USA

*Tel* : /(+1)-858-458-1927 ext 15/
*Fax* : /(+1)-858-458-1847/
*Web page *: www.sccn.ucsd.edu/~arno <http://www.sccn.ucsd.edu/%7Earno>


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20030311/6c9ad307/attachment.htm