Hi Jack,
may I also point out that it isn't really meaningful to judge
differences by looking at post-thresholded maps only. If you're
interested in quantifying the differences you probably want to start
by looking at differences in the unthresholded PEs first.
cheers
christian
On 10 Dec 2005, at 14:27, Jack Grinband wrote:
> Hi Steve,
> Have there been changes over the last few months that would affect the
> results of the fixed effects analysis? I have rerun an analysis since
> installing the latest version of FSL and the results are significantly
> different. For example, in one case the activity went from unilateral
> (previous analysis) to bilateral (latest analysis). thanks,
>
> jack
>
>
> On Fri, 2 Dec 2005 08:29:00 +0000, Stephen Smith
> <[log in to unmask]> wrote:
>
>> Hi Antti, I presume that you are talking about higher-level analysis?
>> There have been improvements in the accuracy of FLAME over the
>> last couple
>> of releases - see previous postings on the email list on this. If
>> you are
>> just seeing minor changes from your old analysis then yes I
>> wouldn't be
>> concerned about that.
>>
>> Cheers, Steve.
>>
>>
>>
>>
>> On Thu, 1 Dec 2005, Antti Korvenoja wrote:
>>
>>> Dear FSL developers,
>>>
>>> I have a question concerning subtle differences in results
>>> obtained with
>>> FEAT v. 5.1 vs. 5.4. It seems to us, that allthough the
>>> parameters were the
>>> same, there are slight differencies in the activation patterns.
>>> Certain
>>> activations that pass the thresholding with little margin in v.
>>> 5.1 are not
>>> seen in the v. 5.4 results.
>>>
>>> I would like to hear your opinion whether the differences are
>>> likely to be
>>> due to differencies between software versions or should we
>>> perform a recheck
>>> of the analysis parameters once again? The activation patterns
>>> are mostly
>>> the same anyhow.
>>>
>>> Greetings,
>>>
>>> Antti Korvenoja
>>>
>>
>> --
>> Stephen M. Smith DPhil
>> 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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