Vision Systems Physiology: Stimuli

Multifocal stimulus The 60-region multifocal experiment is good for automatic localization of the V1 cortex, with some 6% of outlier clusters with the two runs in our 8-channel coil (GE 3T Signa). The timing as indices to the 4-TR miniblocks is included in the a.mat structure, separately for each region. For specifications of the voxel dimensions and other measurement parameters (but another coil), see

Vanni S, Henriksson L, James A: Multifocal fMRI of visual cortices, NeuroImage 27 (2005) 95-105.

You can find the functions creating the stimulus from or Multifocal.tar. This toolbox contains README file, and the functions should be modified to accomodate your needs (e.g. viewing distance, calibration data, the number of regions, etc). In addition the toolbox contains example script for statistical estimation, which is tedious without automation. This toolbox has been published in SPM mailing list, and is currently included as an SPM extension at their web site

If you have any comments, questions, or requests for help in analysis etc, we are most willing to help. Contact henriksson [at] or vanni [at]