Junping Yang wrote:
> Dear SPM users,
>
> I'm trying to use the simple regression of Basic Model to find the areas where change as the ages
> are increasing.
>
> My questions are: 1) Is it right to select the contrast of "effect of interest"?
This uses an F-contrast and will show regions that change positively or negatively.
2) When I get
> the statistical map, how can I discriminate the positive regressions and negative ones?
To do this you should use a t-contrast (not an F-contrast).
A value of +1 over the age regressor will look for positive correlations with BOLD.
-1 for negative correlations.
Best,
Will.
>
> I'm a new user of SPM, and thank you very much for helping me out of such elementary problems.
>
> Thank you in advance
>
> best regards
>
> Junping Yang [log in to unmask]
>
> 2005-07-26
>
>
--
William D. Penny
Wellcome Department of Imaging Neuroscience
University College London
12 Queen Square
London WC1N 3BG
Tel: 020 7833 7475
FAX: 020 7813 1420
Email: [log in to unmask]
URL: http://www.fil.ion.ucl.ac.uk/~wpenny/
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