You are right, it makes sense.
Thank you.
fabienne
Steve Smith a écrit :
> 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
>>
>
>
> ---------------------------------------------------------------------------
>
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ---------------------------------------------------------------------------
>
>
>
>
--
-------------------------------
Fabienne Cazalis, PhD
Semel Institute for Neuroscience & Human Behavior
UCLA School of Medicine
760 Westwood Plaza, Rm 58-217
Los Angeles, CA 90025 USA
|