table of contents
LIPSIA     Average and PCA of fMRI time courses within ROIs
vtc
This program analyses fMRI time series within regions of interest (ROI) specified in a mask. The mask can be generated using 'vledit' or 'vmaskedit'. The time series within each ROI are either averaged or their first principal component (PC) is computed. The resulting averages or PCs are written to a data file, and optionally also printed to an ASCII file.

The data file specified by '-out' mimicks an fMRT raw data file. It can be further processed using a standard sequence of statistical analysis using 'vcolorglm' or 'vwhiteglm' to produce a statistical map containing z-values for each ROI.

The parameter '-type' specifies the way in which the analysis is done. If set to 'mean' the time courses within each ROI are averaged. If set to 'pca', the first principal component within each ROI is computed.

Instead of specifying ROIs in a mask, it is also possible to supply a voxel address. In this case, no averaging or PCA analysis is done. The program then simply outputs the values of this single time course - optionally normalized to N(0,1).

If a report file is specified (parameter '-report'), the output is printed to this file in ASCII.

vtc -in tbsm_xx1t.v -norm true -mask mask.v -out roi.v


Parameters of 'vtc':
-help
Prints usage information.
-in
Input file. Default: (none)
-out
Output file. Default: (none)
-normalize [ true | false ]
Whether to normalize the output to mean=0,sigma=1. Default: true
-type [ mean | pca ]
Type of analysis. Default: (none)
-mask
Mask file. Default: (none)
-minval
Mininum value for time courses. Default: 0.
-report
Report file (ASCII). Default: (none)
-addr
Voxel address (x,y,z) (NOT Talairach coordinates). Default: 0 0 0


Max Planck Institute for Human Cognitive and Brain Sciences. Further Information: lipsia@cbs.mpg.de
Copyright © 2007 Max Planck Institute for Human Cognitive and Brain Sciences. All rights reserved.