Index
Contents
Name
mkcontrast-sess - creates a contrast matrix that is then used as input to test hypotheses.
Synopsis
mkcontrast-sess -contrast <contrastname> -analysis <analysisname> [options]
Arguments
Positional Arguments
None
Required Flagged Arguments
None
Optional Flagged Arguments
-analysis analysisname (or use -an) |
name of session-level functional analysis |
Name of the analysis to create the contrast for. The analysis must have been defined by mkanalysis-sess. Also, selxavg-sess must have been run at least once. |
-contrast contrastname (or use -co) |
contrast name |
The name of the contrast. This name is then used in later programs (eg, stxgrinder-sess). mkcontrast-sess will create a matlab file in the study analysis directory. This file will be called contrastname.mat. When stxgrinder-sess is run, it will create a subdirectory called contrastname under the analysis directory for each sessions. |
-a a1 <-a a2 ...> |
positive contrast conditions |
These specify which conditions to use in the contrast, where 1, a2, c1, c2, etc, are the condition numbers as found in the paradigm file. The -a conditions will be weighted positively. The -c conditions will be weighted negatively. Eg, -a 2 -c 1 -c 3 will weight conditions 1 and 3 by -0.5 and condition 2 by +1. |
-c c1 <-c c2 ...> |
negative contrast conditions |
These specify which conditions to use in the contrast, where 1, a2, c1, c2, etc, are the condition numbers as found in the paradigm file. The -a conditions will be weighted positively. The -c conditions will be weighted negatively. Eg, -a 2 -c 1 -c 3 will weight conditions 1 and 3 by -0.5 and condition 2 by +1. |
-nosumconds |
don't sum conditions (for f-test) |
Specifies that the conditions be tested separately |
-ircorr nircorr |
correlate with gamma function |
|
-deltarange dmin dmax |
range of delta for gamma function |
|
-taurange tmin tmax |
range of tau for gamma function |
|
-umask umask |
set unix file permission mask |
|
-scriptonly |
don't run, just generate a script |
|
-version |
print version and exit |
|
-help |
For FIR Designs
-setwdelay |
prompt for setting of delay weights |
For FIR designs, allows the user to set the weight for each post-stimulus delay. When the program runs, it will prompt the user to enter the weights (eg, if there are 10 points in the FIR, the the user will enter a list of 10 numbers). If you do not want to include a point, set its weight to 0. Eg, if thre are 10 points, but you only want to consider points 3-7, then enter 0 0 1 1 1 1 1 0 0 0. These weights are applied on a condition-by-condition basis. See also -sumdelays. |
-sumdelays |
sum weighted delays |
For FIR designs, sum the points inside the FIR window so that each condition is represented by a single number (ie, the sum). If delay weights have been specified (see -setwdelay), then the weighted sum is computed. |
-rmprestim |
subtract prestimulus baseline |
For FIR designs, compute a contrast such that the average hemodynamicresponse prior to simulus onset is subtracted from the hemodynamic response waveform. This is good for removing baseline shifts. |
Outputs
?? |
?? |
Description
mkcontrast-sesscreates a contrast matrix that is then used as input to test hypotheses. The actual voxel-by-voxel statistical test is performed by stxgrinder-sess.
Examples
Example 1
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Example 2
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Bugs
??
See Also
Links
Methods Description
description description
References
Reporting Bugs
Report bugs to <analysis-bugs@nmr.mgh.harvard.edu>