HI - maybe it just means that these images had no positive values
within the mask?
Cheers.
On 13 Jul 2007, at 16:56, Heather Cogswell wrote:
> Hi Steve,
> Thank you for your prompt reply!
>
> I used the same binary mask for six contrasts on one subject. The
> position of
> the max voxel for some of the contrasts is (0 0 0 ) which does not
> make sense.
> I was wondering why this is happening? Below is a sample featquery
> with the
> above problem (i.e. pe2 and pe4)
>
>
> 1 stats/pe1 5 0.00 0.31 0.59 0.62 0.89 0.89 23 37 7 25.32 1.38 -15.90
> 1 stats/pe2 5 -0.74 -0.74 -0.62 -0.70 -0.39 0.00 0 0 0 103.93
> -112.31 -36.09
> 1 stats/pe3 5 -0.35 -0.35 -0.07 -0.17 0.32 0.32 24 36 7 22.06 -1.59
> -15.59
> 1 stats/pe4 5 -2.54 -2.54 -1.94 -1.92 -1.46 0.00 0 0 0 103.93
> -112.31 -36.09
> 1 stats/pe5 5 -0.13 -0.13 0.52 0.59 0.90 0.90 24 36 7 22.06 -1.59
> -15.59
> 1 stats/pe6 5 -0.65 -0.65 -0.25 -0.45 0.64 0.64 24 37 7 22.03 1.34
> -16.02
>
> Many thanks,
> Heather
>
>
>
>
> Quoting Steve Smith <[log in to unmask]>:
>
>> Hi,
>>
>> On 12 Jul 2007, at 16:30, Heather Cogswell wrote:
>>
>>> Dear FSL users,
>>>
>>> I'm an FSL newbie, so thanks in advance for your help!
>>>
>>> How can I make a mask from a 3rd level activation? I tried
>>> avwroi but it
>>> just creates the mask of the specific voxels that I input . . .
>>> I want to
>>> create a mask of the chosen voxels overlaid on the entire brain.
>>
>> I'm not sure what you're asking - you should probably take the
>> appropriate thresh_zstat image from inside the appropriate
>> something.gfeat/cope??.feat directory and maybe binarise this
>> with avwmaths++
>>
>>> For Featquery analysis I can choose "stats/pe" or "stats/cope".
>>> Which one
>>> should I use for ROI analysis?
>>
>> It's up to you. If this isn't clear then you should probably read
>> the FEAT manual carefully, including the intro to GLM etc stuff
>> in it - hopfully then it will be clear which is what you want.
>>
>> Cheers, Steve.
>>
>>
>>
>>>
>>>
>>> Thanks,
>>> Heather
>>
>>
>> ---------------------------------------------------------------------
>> --- ---
>> 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
>> ---------------------------------------------------------------------
>> --- ---
>>
------------------------------------------------------------------------
---
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
------------------------------------------------------------------------
---
|