Hi Nero,
ANOVA is used in the case where you wish to test hypothesis concerning >2 beta or contrast images. Using a paired t-test on 2 contrast images, as in your case, is more straight forward. Alternatively, you could subtract your contrast images in ImCalc and perform a one-sample t-test.
Best wishes,
Martin
On Feb 23, 2011, at 9:20 PM, Nero Evero wrote:
> Thank you Martin for your quick responses. I have another question, if anyone could help. After completing the 2nd level analysis and creating my contrast, I noticed I had no significantly activated clusters compared to the series of within-subjects contrasts I created earlier. I was curious why that may be; possibly a lack of power (i.e. only 17 subjects) to detect any significant difference between the two treatments? Again, here is a review of my design for my crossover study:
>
> Session 1 --> Treatment 1 --> Scan (Visual paradigm: Active vs. Control)
>
> Session 2 --> Treatment 2 --> Scan (Visual paradigm: Active vs. Control)
>
> Also, would it be reasonable to run a one-way ANOVA for each session (as opposed to a paired t-test) and compare which regions are significantly activated. With this approach I was concerned I would not be able to infer one treatment was signifcantly different than another, would I be correct? Thanks for any comments in advance.
>
> Nero
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