Dear Daiming,
A negative connection from region A to B means that A causes a reduction in B (or, equivalently, reduces that rate of change in B). Similarly for negative driving or modulatory inputs.
Best,
Peter.
-----Original Message-----
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of D. Xiu
Sent: 13 June 2014 15:39
To: [log in to unmask]
Subject: [SPM] negative BMA parameter estimates of connectivities
Dear SPMers:
When I was doing DCM, in order to obtain the effective connectivities, we applied the random effects of Bayesian model averaging (BMA) to acquire subjects’ connectivity estimates across all models (42 models) based on the group winning family. Because I want to analysis the correlation between the connectivities and behaviors. However, for some subjects, the BMA estimates of connectivities are negative. What does the "negative connectivities" mean?
All the bests,
Daiming
|