Can I use FEAT to analyse fmri data from an animal study?
Analysing animal data in FEAT is, in theory, straightforward although there are some practical difficulties. The basic GLM and statistics are no different for animal data, however difficulties can occur during preprocessing – particularly with motion correction and brain extraction. One reason that problems occur is due to the scales used in motion correction, which starts at 8mm and is often too large for animal brains (e.g. rats). A work-around for this is to modify the voxel size recorded in the Analyze header (using fslchpixdim) so that the total brain size is similar to that of a human (150-200mm in each dimension). Once this is done note that all values entered into FEAT in mm will refer to this expanded image, hence the spatial smoothing should be set taking this into account. Problems with brain extraction are more serious and for animals with brains that are considerably different from humans (e.g. rats) then BET normally will not work. In such cases it is necessary to turn of
