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Can you attach the models that you have tried to use. Make sure that you set the group variances to be equal. Also, with 2 measures per subject, there is no sphericity violations. Best Regards, Donald McLaren ================= D.G. McLaren, Ph.D. Research Fellow, Department of Neurology, Massachusetts General Hospital and Harvard Medical School Postdoctoral Research Fellow, GRECC, Bedford VA Website: http://www.martinos.org/~mclaren 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 Thu, Jan 10, 2013 at 1:39 PM, Devin Sodums <[log in to unmask]> wrote: > Dear SPM experts, > > I am trying to take a patient who has done the same test twice and run a flexible factorial design to see if there are any differences between scans. My end goal is to use the con.img's that would be outputted as another comparison with a group of controls that have also done the test twice. I have gotten the "no significant voxels." message each time I try comparing the single patient's scan 2 to scan 1. > > I have used a two-sample t-test, ANOVA-within a subject, and flexible factorial design, and each of them is still giving me the same error. After reading the posts about changing the independence and variance such that non-sphericitiy is assumed, yet I still receive the same message. I have checked the images with checkreg and they are the same dimensions and everything. I have also tried changing the defaults.stats.fmri.ufp to a more liberal threshold (from 0.001 to 0.01 and even to 0.1) but also still receive the same error message. > > This is the first time I have tried comparing a single subject's first and second scans, so perhaps I am doing something wrong to begin with? From what I have read, repeated measures analysis is appropriate, and I believe I set it up appropriately as well. > > Any advice/help would be greatly appreciated. > > Thank you, > > Devin