Table files

Table files are used for analysis using the first-level programs for fMRI or PET data. The format is very simple and general:

  • The first line contains a list of text headers. The number of text words must match the number of following data columns.
  • After the first line, each subsequent line contains a number of data values equal to the number of text headers on the first line.

The number of data rows in the table must match the number of time points in the corresponding data file. The number of tables columns is arbitrary, except that at least one column must exist for the PET SRTM analysis; the first column is the length of each time frame in the PET reconstruction in units of seconds. Such a file MUST be used for PET analyses to provide the length of all frames.

In the fMRI analysis package, the time model control file (“timeModel.dat”) might look like this:

      runs:

      ../subject1/run1.nii ../subject1/run1.glm  …/subject1/run1.table

and file “run1.glm” could contain entries like this:

     x table 1  # x shift from motion-correction

     y table 2 # y shift from motion-correction

with the table file looking like this (note column references start with index 0, so that “x-shift” is column 1).

index x-shift y-shift z-shift eye-x eye-y my-drug-regressor

0   0.1045  -0.2479 0.3621 4.57 -3.02 0

1   0.1153  -0,.2283 0.2892 4.58 -3.26 0

Joseph B. Mandeville, Athinoula A. Martinos Center for Biomedical Imaging at MGH/MIT/Harvard