Re katrien,
> the thing was to restrict analyses to areas that are relevant for the
> verb generation task before comparing groups (not entire brain,
> because then differences between groups are too small).
>
> so to define which areas are activated by verb generation (versus
> control: -1 0 1 as only contrast that interests me, not the drawings),
> I perform a 1ST with all sessions.
> so 37 sessions with results from the contrast -1 0 1 (individual,
> first level analysis) are used in a 1ST test with contrast 1 (second
> level analysis) to assess general verb generation activation.
> this gives me a con.img, a mask.img and a SPM_T.img [...]
Ok, you've got the main effect of nouns versus drawings .. now you want
to go further into details limiting your analysis to some areas. As I
proposed to you, one solution is to save this thresholded result ('save'
button in the visualisation panel). This result should be corrected for
multiple comparisons. Then, you can use it as a mask.. the WFU pickatlas
is doing a good job for that. Using other maps as con or smpT using
imcalc is not a good option, because of the mandatory statistical
thresholding...
>
> i hope i'm not driving you crazy ;-)
Well... ;-)
I hope this helps you ... tell me if not
Best
- cyril
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