You need an F-test (I label this as the omnibus F-test) that has N rows, where N is the number of conditions. In your 2 sample t-test: [1 0; 0 1] Then plot the F-test. For more complicated designs, this might not always be eye(N). But you can build the contrast for each condition and put it into a single F-contrast. Best Regards, Donald McLaren ================= D.G. McLaren, Ph.D. Postdoctoral Research Fellow, GRECC, Bedford VA Research Fellow, Department of Neurology, Massachusetts General Hospital and Harvard Medical School Office: (773) 406-2464 ===================== This e-mail contains CONFIDENTIAL INFORMATION which may contain PROTECTED HEALTHCARE INFORMATION and may also be LEGALLY PRIVILEGED and which is intended only for the use of the individual or entity named above. If the reader of the e-mail is not the intended recipient or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that you are in possession of confidential and privileged information. Any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited and may be unlawful. If you have received this e-mail unintentionally, please immediately notify the sender via telephone at (773) 406-2464 or email. On Mon, Aug 29, 2011 at 1:47 PM, Claire (Jung Eun) Han <[log in to unmask] > wrote: > Dear experts, > > I would like to plot the contrast estimate and 90% C.I. for the areas that > activated for a contrast of interest. > For anova, our lab created and used a f-contrast to plot the contrast > estimate (which shows the effect size for each condition for coordinates at > activation). > I do not know which contrast that I need to create which can be used to > plot the contrast estimate. In other words, what contrast should I put when > the SPM interface asks me after choosing to 'plot' and then 'Contrast > estimates and 90% C.I.'...My aim is to look at the effect size for each > condition for each group (compared to the 'baseline'). > > It was a two samples t test done. I have attached the graphics that may > help. > Hope my explanations are clear... > > Thanks, > Claire >