Dear DCM experts
Our model includes a region that shows deactivation in the conventional
analysis (greater activation for fixation > words).
Our DCM analysis shows that this region has significant negative
bidirectional intrinsic connections with other regions.
The results also show significant negative modulatory effect of the task
(words) on the output connections from this region.
My questions are:
1 - How can one interpret negative intrinsic connections? can they reflect
a direct inhibition?
2- How can one interpret negative modulatory effect on a negative
intrinsic connection? (Does it mean the task increases the negativity of
the connection, so there is MORE inhibition during the task; or does it
mean the task decreases the absolute strength of the connection, so there
is less inhibiton during the task?)
3- When a region shows deactivation in the conventional analysis, would it
necessarily show negative modulatory effects of input or output
connections?
I would very much appreciate your help.
Tali Bitan
Northwestern University
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