Dear SPM community,

I have a problem with a specific graphic representation of contrast images in the SPM glass brain. The contrast images represent the differences between pre- and post- conditions after the second level analysis by a paired t–test. Because in SPM the paired t–test is two-tailed, both directions of differences are considered and therefore those brain areas involving increased and decreased brain activations are displayed in the SPM glass brain. I would like to separate both directions graphically and to show after the paired t–test analysis one time only brain regions, where activation is increased in the post-condition and another time only brain regions, where activation is decreased in the post-condition. I can’t find any possible programming option in SPM or MATLAB how to separate images showing increased from images showing decreased activation in the SPM glass brain after a paired t–test analysis?

Kind regards and many thanks for helping me!

Dipl.-Ing. Andreas Jell

Heinrich-Heine-Universität
Institut für Experimentelle Biologische Psychologie Gebäude 23.03
Universitätsstraße 1
D-40225 Düsseldorf

[fon] +49 (0)211 81-13958
[fax] +49 (0)211 81-14522

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