Hello,

My question is about conceptual realignment during preprocessing. I am trying to determine which approach would be better during preprocessing:

1) Realigning all sessions to one image, resulting in one mean image. That mean image would then be used in coregistration of the structural image followed by segmentation, normalization, and smoothing.

2) Realigning each session individually to an image in each respective session. This would generate 3 mean images. Using each mean image in different coregistration, segmentation, normalization, and smoothing. By different I mean conducting these steps individually for each session. I realize that I would be getting 3 sets of segmented images with this approach. 

Would (2) be a better approach than (1) since images within a particular session are more closely aligned?Whereas there may be more substantial head movement between sessions.

From,
Humza Ahmed