You can use the following matlab code. You can ignore the warning printed after the toepliz operation. The OriginalRegressor should be a vector of length Ntp, then write out the NewRegressor to a new external regressor file.

TR=2; % seconds

Ntp=100; t = TR*[0:Ntp-1]';

h = fast_spmhrf(t);

a = zeros(Ntp,1); a(1) = 1; X = toeplitz(h,a);

NewRegressor = X*OriginalRegressor;

On 02/21/2017 04:02 PM, Reza Rajimehr wrote:

Hi Doug,

Since our external regressors are stimulus-related (e.g. mean luminance of stimuli), we need to convolve them with a hemodynamic response function. In mkanalysis-sess, we have used -spmhrf 0 to model conditions. Is there a code or Matlab script for HRF convolution, so that we apply exactly the same spmhrf function for modeling the external regressors?

Thanks, Reza

No, they are not

On 02/17/2017 05:09 PM, Reza Rajimehr wrote:

...

/During the functional analysis in FS-FAST, are the external regressors />/convolved with the hemodynamic response function? />//>/Thanks, />/Reza />//>//>/_______________________________________________ />/Freesurfer mailing list />/Freesurfer at nmr.mgh.harvard.edu

https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer />/https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer /

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