[Eeglablist] Subjects head size

[Robert Oostenveld]

Hi Birju

Most important is to get the ratios between skin, skull, csf and brain 
correct. The real size of the head with which you could multiply these 
ratio's only ends up as scaling factor in the dipole position. 
Internally the forward computation uses dimensionless values, and works 
with relative dipole excentricity.

If you want to map a dipole position onto an MRI, you should get the 
dimensions as accurate as possible. The default dimensions of the 
spheres in DIPFIT are the same as in BESA. They are not neccesary 
optimal for your individuals MRI, or even for the cannonical MRI that 
is included in EEGLAB.

best regards,
Robert

On 9 Mar 2004, at 18:26, Birju Patel wrote:

> Hi,
>
> I'm trying to figure out the what value should be input for the shell 
> radii
> (skin) in the pop_dipfit_settings().  What is the best measurement to 
> take
> of a subject's head size for use in a spherical head model?
>
> Thanks,
> Birju Patel
>
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