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Hi Giovanni, I think the type of analysis you want to perform is a conjunction. If you have contrast one for event A and contrast two for event B, you can hold down the shift key and select both contrasts, upon which spm will perform a conjunction for you. As to the different types, there are a couple of papers on this (of which you may want to start with the most recent ones as the concept evolved somewhat :) Cheers, Marko Giovanni Cosmati wrote: > Dear SPMers, > > I'm running a group study. > > I have 2 event types, A and B, from which I obtain 2 contrasts (cA, cB) at the single subject stage (i.e. 1st level analysis). > > Assuming that at the group level stage (i.e. 2nd level analysis) I want to show areas that are activated both by event A AND by event B, how should I proceed? > Is there a specific design at the 2nd level that I can use for this purpose? Or can I use some kind of computation with ImCalc, like cA*cB with a certain thresholding or scaling factor? Or the correct way is to generate a t-contrast at the 1st level for the logical AND of A and B (how?) and then run a t-test on this contrast at the 2nd level? > > Thank you in advance for you answer, > > Giovanni > -- ____________________________________________________ PD Dr. med. Marko Wilke Facharzt für Kinder- und Jugendmedizin Leiter, Experimentelle Pädiatrische Neurobildgebung Universitäts-Kinderklinik Abt. III (Neuropädiatrie) Marko Wilke, MD, PhD Pediatrician Head, Experimental Pediatric Neuroimaging University Children's Hospital Dept. III (Pediatric Neurology) Hoppe-Seyler-Str. 1 D - 72076 Tübingen, Germany Tel. +49 7071 29-83416 Fax +49 7071 29-5473 [log in to unmask] http://www.medizin.uni-tuebingen.de/kinder/epn ____________________________________________________