Print

Print
Hello everybody,

I have a question with respect of SPM volume images derived from MEEG source reconstruction (and thus from cortical surface meshes). In the manual of SPM8 it states:  "SPM statistical machinery has been optimized to deal with these peculiarities and get sensible results. This presently only works for T-contrasts but not for F." Can anybody explain me why this is the case? How are "these peculiarities" dealt with in case of T contrast and what one should do to be able to compute sensible F contrasts?

Thanks a lot in advance,

Best,

Stephan

________________________________________________________
Stephan Moratti, PhD

see also: http://web.me.com/smoratti/

Universidad Complutense de Madrid
Facultad de Psicología
Departamento de Psicología Básica I
Campus de Somosaguas
28223 Pozuelo de Alarcón (Madrid)
Spain

and

Center for Biomedical Technology
Laboratory for Cognitive and Computational Neuroscience
Parque Científico y Tecnológico de la Universidad Politecnica de Madrid
Campus Montegancedo
28223 Pozuelo de Alarcón (Madrid)
Spain


email: [log in to unmask]
Tel.:    +34 679219982

El 14/12/2012, a las 18:37, Aggie McMahon escribió:

Hello again!
I have a screen shots contrasting my grey matter results when the only thing I have altered in the VBM8 estimate & write step is the tissue probability map (TPM).  I have also included a screen shot of each tissue map 1-6, in the SPM8 default TPM and my TOM8 TPM.
The differences of the TPM's, while obvious, don't strike me as significant enough to produce the skewed VBM results when using the TOM TPM.  This is the same effect across all subjects.  Any thoughts / suggestions / similar problems?
Thanks, SPMers!
-Aggie
<comparison_GM.png><comparison_TPM.png>