Hi Dorian
For more detail on doing within-subjects ANOVAs in SPM, I would also
recommend this guide:
http://www.mrc-cbu.cam.ac.uk/people/rik.henson/personal/HensonPenny_ANOVA_03.pdf
best regards,
Jonathan
On Mon, Oct 19, 2009 at 7:23 AM, Stephen J. Fromm <[log in to unmask]> wrote:
> On Fri, 16 Oct 2009 13:45:08 +0200, Dorian P. <[log in to unmask]> wrote:
>
>>Thank you for answering.
>>
>>Now I understand the reason behind that. But how can I investigate
>>interactions amongst conditions in 2nd level without loosing the
>>statistical power this way?
>>
>>The one-sample (and paired t-test) show activity without any doubt
>>(FWE corrected, k=5). If I use ANOVA, instead, it will simply
>>disappear even at p < 0.001. Previously I thought setting
>>"independence = no" would be the same as doing the contrasts in 1st
>>level. Apparently I was wrong. Can we conclude that ANOVA is producing
>>false negatives and stick to analysis without interactions? What would
>>you do in my case?
>
> Make sure you model the effect of subject in your second level ANOVA.
>
> You can get info on how to do that by searching the list like
> anova AND "effect of subject"
> or
> anova AND "subject effects"
>
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