 |
 |
Dear Morgan, SPM will be able to tell you which voxels are more active under condition 1 than condition 2 (or vice-versa). You'll first need to re-align, normalise and smooth your images (using the Realign, Normalize and Smooth buttons). Then set up a general linear model (GLM) that models the activity at each voxel as a function of condition (using the fMRI models button). You then specify a 'contrast' which picks out voxels showing significantly greater activity under condition 1 than 2 (using the Results button). See http://www.fil.ion.ucl.ac.uk/spm/course/notes01/intro/img3.htm for an overview, and eg. http://www.fil.ion.ucl.ac.uk/spm/course/notes01/glm/welcome.htm for details on setting up the GLM. Hope this helps, Will. morgan wrote: > I am looking for some advice on analyzing an fMRI time series. What > I have is an fMRI paradigm which involves 30s of rest (no imaging) > followed by 90s of stimulus (no imaging) then 30s of stimulus > with imaging. This is repeated three times for one condition > then three times with a second condition. I have been using spm > for only a short time and would apreciate any advice. -- William D. Penny Wellcome Department of Cognitive Neurology University College London 12 Queen Square London WC1N 3BG Tel: 020 7833 7478 FAX: 020 7813 1420 Email: [log in to unmask] URL: http://www.fil.ion.ucl.ac.uk/~wpenny/