Hi,
I assume you are talking about a second-level group FEAT post-
analysis? In which case the filtered_func_data being fed into this is
the inputs to the second-level analysis, i.e. all subjects/sessions'
COPEs brought up from the outputs of the first-level analyses.
Hence when you run fslmeants you get an average of this across the ROI
that you feed in. I think the main answer to your question is in
understanding what COPEs are - I suggest maybe starting by reading the
GLM overview in the FEAT manual
http://fsl.fmrib.ox.ac.uk/fsl/feat5/glm.html
Cheers
On 16 Jul 2008, at 17:15, fabienne wrote:
> Hello,
>
> I wish to understand exactly what the fslmeants output represents.
>
> When I run fslmeants on "Single-Group Average" (One-Sample T-Test)
> data, using a ROI mask, I obtain positive and negative values. My
> understanding is that those values are average timeseries of
> intensities collapsed across the voxels inside the region of
> interest, and that I obtain one value for each individual of this
> group.
>
> However, I wonder in relation to *what* are those values positive/
> negative?
> Since this is a simple average of one event, not a contrast.
>
> Thank you for your help, and thank for this amazing list.
> Fabienne
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
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