AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

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bob cox
August 07, 2003 07:16PM
3dDeconvolve has a linear model for data in each voxel:

v[n] = stim[0]*iresp[n] + stim[1]*iresp[n-1] + stim[2]*iresp[n-2] + ... + baseline[n] + noise

The stim[] time series you input with the -stim_file options. The program computes the iresp[] time series (with iresp[j] nonzero only for j between min lag and max lag).

The fitts output is the fitted model, which is the equation above without the noise. This is good for plotting on top of the data (v[]) time series so that you can see if the model captures most of the interesting features of the data.

The iresp[] time series, which is usually very short compared to the data and fitts time series, is useful for determining the amplitude and shape of the response. The statistics of the iresp[] time series (the partial and/or overall F scores) are what you use "to figure out how well stimuli in a experiment are causing an effect".

bob cox
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Subject Author Posted

-fitts vs. iresp

Michael August 07, 2003 05:51PM

Re: -fitts vs. iresp

bob cox August 07, 2003 07:16PM

Re: -fitts vs. iresp

Michael August 08, 2003 09:20AM