Hi - this is calculated from the design.con header which tells you the
peak-peak height of the "effective regressor" (see our NeuroImage
efficiency paper) associated with contrast 1 - so have a look at this
file and the design in general - did something go weirdly wrong with
this design matrix?
Cheers.
On 12 May 2009, at 18:18, James Porter wrote:
> Howdy-
>
> I have a follow-up question. I'm going through the featquery shell
> script
> and logs, and I'm not quite able to follow all parts. Specifically,
> I can't
> tell where the value 24.2645433553 comes from in the following log
> line.
>
> /opt/bliss/fsl/bin/fslmaths stats/cope1 -mul 24.2645433553 -div
> mean_func
> cope1.feat/featquery/tmp
>
> For the problem subject discussed below, the value is 4.91862312076e
> +16, and
> this seems to be the source of the goofy percent signal change values.
> However, I'm still unable to diagnose the root problem without
> knowing where
> the value in question comes from. Can you point me in the right
> direction?
>
> Thanks in advance,
> Jim
>
>
>
> On Thu, 7 May 2009 15:08:22 -0500, James Porter <[log in to unmask]>
> wrote:
>
>> Hello-
>>
>> Can anybody clue me in on an obvious reason why one subject (47 other
>> subjects do not show this problem) would have insanely large percent
>> signal change values--but not z-values--when running a masked
>> featquery
>> examination? We're talking absurdly large values, like
>> 370,200,000,000,000 % signal change, and the values are identical for
>> all of the descriptive stats (i.e., min, mean, max are all the same
>> value).
>>
>> --
>> ---------
>> Jim Porter
>> Graduate Student
>> Clinical Science & Psychopathology Research
>> University of Minnesota
>
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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
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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