Where are there instructions to include motion parameters as extra EVs?
On Tuesday, February 25, 2003, at 10:17 AM, Jonathan Brooks wrote:
> Hi,
>
> You could also try including the motion parameters as extra EVs - I
> guess the spike in
> the MC data might "detract" from the fit to the functional data at that
> timepoint, thus reducing
> its influence on the activation map. But Steve's suggestion is probably
> best :)
>
> Yours,
>
> Jon.
>
> Stephen Smith wrote:
>
>> Hi - there isn't currently a way to do this, no; whilst this is an
>> easy
>> thing to do in simple OLS, the complexity of the prewhitening step in
>> FEAT's time-series analysis makes this a messy thing to allow.
>>
>> The simplest workaround is to somehow clean up those images, for
>> example,
>> by replacing the dodgy time points with local (temporal) median/mean
>> images.
>>
>> Thanks, Steve.
>>
>>
>>
>> On Mon, 24 Feb 2003, Zrinka wrote:
>>
>>
>>
>>> Hello!
>>>
>>> Is it there a way (in feat) to ignore certain time points within a
>>> functional run? I have some datasets that have some big but brief
>>> motion
>>> and I would like to ignore those points when calculating stats. (AFNI
>>> allows this by modifying the equivalent of design.mat such that
>>> ignored
>>> points' values are changed to 99999).
>>>
>>> Thank you!
>>>
>>> Zrinka
>>>
>>>
>>>
>>
>> Stephen M. Smith MA DPhil CEng MIEE
>> Associate Director, FMRIB and Analysis Research Coordinator
>>
>> Oxford University Centre for Functional MRI of the Brain
>> John Radcliffe 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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