Dear DCM-PEB experts,
I am currently using DCM-PEB to test if two conditions (A and B) modulate the effective connectivity between visual and motor areas in a different way. At the first level, bilateral visual and bilateral motor areas were involved, and the between-region connections were modulated by both conditions A and B. After the group-level analysis, I found that condition_A positively modulated the bottom-up connections from the left visual to the left motor, while condition_B positively modulated the bottom-up connections from the left visual to the right motor (you can find the figure of the results attached) across subjects.
Now I wonder if I could compare these two positive modulatory effects directly.
Because the different modulation effects on the sensorimotor connections due to the two conditions are the main interest of our study.
However, I realized these two parameters were calculated involving different target regions (one was calculated using the left motor area timeseries, and the other with the right motor area timeseries)...
If it is doable, I feel like, for each subject, two DCMs will need to be fitted, one for the network architectures only including the right motor area, and the other for that only including the left motor areas. That means, there will be GCM_RightMotor and GCM_LeftMotor. Then at the second level, a PEB model will be used to test the difference between the right and left motor related connections using 1 and -1 regressors.
Any suggestions would be greatly appreciated. Thank you very much in advance.
Best wishes,
Yuqian Yang
|