 |
 |
Dear SPMers, Concerning the voxel "raw" time-course in fMRI, SPM99: I wonder what the unit of the adjusted data of a voxel (xY.y) is. One gets these data as a long vector (column of numbers) after using the Results-VOI option (radius 1 mm); and also as the y variable after using the plot option. Scans of all sessions are concatenated (in my case 6 subjects with 6 sessions: 36 sessions in total). In SPM 99, it seems to be percent change of signal, is this correct ? But what is 100 % then, is it the mean value of the voxel across all sessions after normalization for global changes (I used "scaling" to normalize) ? Could anyone explain, please ? In SPM 96 (if I remember correctly), the variable y gave a matrix was arranged session by session. Furthermore, these data were not centered around zero, as in SPM 99. Thank you very much Johann Kuhtz-Buschbeck Dept of Physiology Kiel University D 24098 Kiel, Germany e-mail: [log in to unmask]