Dear SPM experts,
I'm struggling with the problem of concatenating onsets in a
multisession design. In my case I have
- 4 sessions (200 scans per session, TR = 2000 ms).
- Prior to the beginn of each session and after its end there were some
dummy scanns.
- Event onsets (duration = 3000 ms) were referenced to the begin of the
first scan in a given session.
This information was sufficient to model the data in a
multi-sessions-design. But I just realized that for the concatenation
I'm missing precise information about when the recording was stopped in
each session.
Would it be correct to assume, that my session lasted for 400 seconds
(200 scans * 2000 ms)? In this case the concatenated onsets would look like:
session 1: onset_1.1, onset_1.2 ....
session 2: onset_2.1+ 400 sec, onset_2.2+ 400 sec ...
session 3: onset_3.1+ 800 sec, onset_3.2+ 800 sec ...
...
Is this precise enough or is there probably a better solution for
concatenating onsets?
Many thanks in advance!
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