Hi
the filtered_func_data is the data that feeds into the analysis, not  
the output - so yes, it will still have voliume 14 in it. The easiest  
way of checking that Feat ignored the 14th volume is to have a simple  
contrast on the EV - the COPE image should be identical to the de- 
meaned (across time) 14th image from filtered_func data (note that in  
your design you want to switch off convolution , filtering and  
temporal derivative for this EV).
Also, are you certain that the upload worked? Our system cant find  
anything with that upload ID.
cheers
christian



On 4 Aug 2006, at 20:37, Gonzalo Rojas Costa wrote:

> Dear Mark:
>
>   I used a custom EV to ignore the 14th volume of a study, because  
> it has
> a strange "artifact" (miss ordering of some slices)... How can I  
> verify if
> FSL ingored that volume during the fMRI processing (I view the file
> filtered_func_data.nii.gz but it currently has that 14th volume) ?...
>
>   Could you please send me the answer as soon as posible...
>
>   Besides, do you know why occurs that "artifact" ?... I uploaded the
> complete study (ID: 158909)...
>
>   Sincerely,
>
>
> Gonzalo Rojas Costa
>
>
> On Mon, 31 Jul 2006 10:33:18 +0100, Mark Jenkinson  
> <[log in to unmask]>
> wrote:
>
>> Dear Gonzalo,
>>
>> I'm not sure why you need to skip the first two volumes of each  
>> period.
>> This is certainly not a normal thing to need to do.
>>
>> If you do have a very good reason for needing to do this, then the
>> best approach is to include separate EVs (regressors) of no interest
>> for each time point that you want to ignore (or "skip").  For  
>> example,
>> if
>> you wanted to ignore timepoints 0, 1, 10, 11, 20, 21, 30 and 31  
>> then you
>> would include 8 separate EVs.  The first EV would have a one at
>> timepoint
>> 0 and zeros for all other timepoints.  The second would have a one at
>> timepoint 1 and zeros for all others.  The third would have a one at
>> timepoint 10 and zeros for all others.  And so on.  These are easy to
>> make with custom EVs or by using the square wave input with  
>> appropriate
>> "skip" and "stop after" settings.  It is also important that you turn
>> off both convolution and temporal derivative (but leave temporal
>> filtering on).
>>
>> If you do this then you will effectively remove all of the signal
>> contributed from these timepoints, but without introducing the nasty
>> effects which would occur if you just removed these timepoints from
>> the data.
>>
>> Before you do go ahead and do this, however, please think about why
>> you would do this in case it is not necessary.
>>
>> All the best,
>> 	Mark
>>
>>
>>
>> On 29 Jul 2006, at 18:48, Gonzalo Rojas Costa wrote:
>>
>>> Hi:
>>>
>>>   I have an fMRI study with TR = 4 seconds, 10 temporal dynamics per
>>> off-
>>> on period (40 seconds duration each off-on period)... I must skip  
>>> the
>>> first two dynamics of each off-on period to process the study... How
>>> can I
>>> do it with FSL ?...
>>>
>>>   Sincerely,
>>>
>>>
>>> Gonzalo Rojas Costa
>>> Service of Neuroradiology
>>> Institute of Neurosurgery Dr. Asenjo
>> ===================================================================== 
>> ====

--
  Christian F. Beckmann
  Oxford University Centre for Functional
  Magnetic Resonance Imaging of the Brain,
  John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
  Email: [log in to unmask] - http://www.fmrib.ox.ac.uk/~beckmann/
  Phone: +44(0)1865 222551 Fax: +44(0)1865 222717