Dear Geon-Ho,
no, you don't need extra smoothing in most cases.
Volkmar
On Fri, 7 Sep 2007, Geon-Ho Jahng wrote:
> Dear Volkmar,
>
> Thank you for advise. Do I need to smooth again the con images that generate
> from the 1st level analyses? Currently, I directly use the con images
> without smoothing.
>
> Best
> Geon-Ho
>
>
>
> On 9/6/07, Volkmar Glauche <[log in to unmask]> wrote:
>>
>> Dear Geon-Ho,
>> something went wrong while estimating spatial smoothness of the residuals
>> of your 2nd level model. This is difficult to track, but you should check
>> your data - they may have sharp edges in them, or they may have only
>> discrete values - try looking at an histogram of your data using the
>> volumes toolbox.
>>
>> Volkmar
>>
>>
>> On Thu, 6 Sep 2007, Geon-Ho Jahng wrote:
>>
>>> Dear All,
>>>
>>> After we finish the first level analysis, we try to analyze the second
>> level
>>> using "con" images with paired t-test of pre- and post- fMRI task.
>>> During the Estimation of the paired T-test model, I got the following
>> error
>>> message. Please give me an advise how to solve?
>>>
>>>
>>> Plane 69/69 , block 2/2 : ...closing
>> files
>>> Spatial non-sphericity (over scans) : ...estimating derivatives
>>> Spatial non-sphericity (over scans) : ...writing resels/voxel image
>>>
>>> Warning: Divide by zero.
>>> (Type "warning off MATLAB:divideByZero" to suppress this warning.)
>>>> In C:\MATLAB6p5\toolbox\matlab\datafun\mean.m at line 26
>>> In c:\spm\spm2\spm_est_smoothness.m at line 150
>>> In c:\spm\spm2\spm_spm.m at line 880
>>> Warning: Divide by zero.
>>> (Type "warning off MATLAB:divideByZero" to suppress this warning.)
>>>> In C:\MATLAB6p5\toolbox\matlab\datafun\mean.m at line 26
>>> In c:\spm\spm2\spm_est_smoothness.m at line 151
>>> In c:\spm\spm2\spm_spm.m at line 880
>>> ??? Second argument must be numeric, real, full and double.
>>>
>>> Error in ==> c:\spm\spm2\spm_resels_vol.dll
>>> Error in ==> c:\spm\spm2\spm_spm.m
>>> On line 881 ==> R = spm_resels_vol(VM,FWHM)';
>>>
>>> ??? Error while evaluating uicontrol Callback.
>>>
>>>>>
>>> Best
>>> Geon-Ho
>>>
>>>
>>>
>>>
>>>
>>
>> --
>> Volkmar Glauche
>> -
>> Department of Neurology [log in to unmask]
>> Universitaetsklinikum Freiburg Phone 49(0)761-270-5331
>> Breisacher Str. 64 Fax 49(0)761-270-5416
>> 79106 Freiburg http://fbi.uniklinik-freiburg.de/
>>
>
>
>
>
--
Volkmar Glauche
-
Department of Neurology [log in to unmask]
Universitaetsklinikum Freiburg Phone 49(0)761-270-5331
Breisacher Str. 64 Fax 49(0)761-270-5416
79106 Freiburg http://fbi.uniklinik-freiburg.de/
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