pritha das wrote:
> Dear Will,
>
>
>
> I?m following the procedure described in the text file called README GLM
> PPI.txt (available from your website
> http://www.fil.ion.ucl.ac.uk/~wpenny/datasets/attention.html) to do PPI
> analysis. In the results section we choose a t-contrast in such a way
> that the interaction column has value 1 and all others 0 to see the
> regions whose responses have been
this should be 'positively modulated'
> modulated because of this interaction.
> Instead of +1 if I choose -1 what does the result tells me?
>
this would be 'negatively modulated'.
ie. this would show voxels having a correlation with V2 that
*decreases* during periods of high attentional load.
Best, Will.
>
>
> Thank you very much for your help.
>
>
>
> Best Regards,
>
> Pritha
>
--
William D. Penny
Wellcome Department of Imaging Neuroscience
University College London
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London WC1N 3BG
Tel: 020 7833 7478
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URL: http://www.fil.ion.ucl.ac.uk/~wpenny/
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