We use a task with a rapid, event-related design- with 6 s trials and a TR of 2 s. We hope to be able to disentangle activations relating to events WITHIN that brief 6s time frame. Thus, changes in 3dTshift seem huge.

Our subjects are scanned axially. To select the montage, I put up a midsagittal image and draw the 24 slices starting at the base of the orbitofrontal cortex moving the mouse cursor upward to the top of the corpus collosum. Since I am moving I to S with cursor, and the images are interleaved by default in RT-EPI, I use the "altplus" option in AFNI to interpret the I files.

My question is, what is different about the new 3dTshift? When Bob says the old one was "backwards", does that mean that assuming the images were actually acquired in the following order (I to S):

SUPERIOR
*******
24
12
23
11
22
10
21
9
20
8
19
7
18
6
17
5
16
4
15
3
14
2
13
1
*******
Inferior

.... that instead ANFI was incorporating the slice data upside-down (in my axial case) as:

1
13
2
14
3
15 etc.

or was it reversing direction when "reading-in" the single slices, like:

Superior
*******
13
12
14
11
15
10
16
9
17
8
18
7
19
6
20
5
21
4
22
3
23
2
24
1
****
INFERIOR

With our small areas of interest coupled with rapid events, the new datasets made with the revised 3dTshift have changed the overall multi-subject consolidated group maps considerably, and it would be nice to have some idea why.

Thanks.

Jim B