Dear Steffie,
SPM can do the thresholding for you.
If you are doing a cluster size inference this will be on the
t-statistic image.
(so that only those voxels from the cluster inference appear in the MIP
in SPM8 do (i) select a low height threshold eg. 0.001 uncorr, (ii) look
at FWEc at the bottom of the resulting stats table, (iii) select the
contrast again, select 0.001 uncorr for height again, and then FWEc for
extent. SPM will then only display clusters containing more than FWEc
voxels).
You can then save the image of above threshold voxels (ie those voxels
that appear in the MIP) by pressing the save button (in SPM's bottom
left window). It will ask you for a name for this file.
You can then load this into xjview.
Best, Will.
Steffie Nelson wrote:
> Hello Imagers –
>
>
>
> I’ve just completed a 2^nd level analysis across 15 subjects using all
> of the con_0001.img files for the contrast I’m targeting.
>
>
>
> In my resulting folder, I have several images:
>
>
>
> beta_0001.img
>
> ess_0001.img
>
> spmF_0001.img
>
> spmT_0002.img
>
>
>
> Which of these do I use for statistics? Meaning, on which image do I
> now apply a threshold p-value and cluster size? I seem to get different
> results in xjview depending on which image I use, which is why I ask.
>
>
>
> Thanks in advance,
>
>
>
> Steffie
>
>
>
>
>
--
William D. Penny
Wellcome Trust Centre for Neuroimaging
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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