Dear Debora
I'm assuming the subjects with low explained variance had little or no activation in their SPM analyses (particularly in the region(s) that receive driving input).
You can either include the subjects with little or no activation - acknowledging that a representative sample of the population will include some people for whom experimental effects couldn't be detected - or you can exclude them, focussing your results on just those who do show activation. Both approaches have been used and can reasonably be justified.
All the best
Peter
-----Original Message-----
From: SPM (Statistical Parametric Mapping) <[log in to unmask]> On Behalf Of Debora Toro
Sent: 22 March 2024 09:28
To: [log in to unmask]
Subject: [SPM] Subjects with less than 10% explained variance in DCM_PEB
⚠ Caution: External sender
Dear SPM and DCM experts,
I'm running a DCM analysis. While checking diagnostics I noticed the presence of some subjects with poor explained variance (less than 10%). After checking their single-subject First level SPM Maps, am I entitled to esclude these subjects from the 2nd level DCM analysis? Does the esclusion of these subjects affect the results obtained from the model comparison?
Best regards
Debora
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