Hi Reza, Your interpretation of the timing is correct. The validation segment in each movie scan was shifted by 40-200ms for the "v2" version. This was done in order to make that final 83 second clip begin precisely at the start of the next TR for all 4 movie sessions.
Given HRF variability, ignoring this change will probably not adversely impact most analyses. -Keith On Fri, May 31, 2019 at 9:05 PM Reza Rajimehr <rajim...@gmail.com> wrote: > Hi, > > The HCP S1200 Reference Manual says that there are two versions of 4 movie > files. Some subjects have been scanned with one version, and the remaining > subjects have been scanned with another version. Version 2 includes these > changes: > > 7T_MOVIE1_CC1_v2 remains unchanged. > > 7T_ MOVIE2_HO1_v2 removed 1 frame of rest before the validation clip. > > 7T_MOVIE3_CC2_v2 removed 5 frames of rest before the validation clip. > > 7T_MOVIE4_HO2_v2 added 4 frames of rest before the validation clip. > > Here *frame* is a frame of the movie, right? > > Assuming that the movies are ~25 frames per second, the deviations are > between 0 and ~200 ms in each movie file. Considering the TR of one second > and the slow hemodynamic BOLD responses, these deviations are negligible, > and we can possibly ignore them when concatenating time-series data across > all subjects. Would you agree? > > Thanks, > Reza > > _______________________________________________ > HCP-Users mailing list > HCP-Users@humanconnectome.org > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users