Hi,
Sorry, not clear what you mean - you mean you want to turn a user-
defined cluster extent into a p-value? Not sure what you'd want to do
that though.....?
Cheers.
On 19 Feb 2009, at 15:50, Markus Ploner wrote:
> Hi Steve,
>
> thanks a lot for the kind answer. I will try to familiarize myself
> with
> TFCE. However, is there, in principle, a way to calculate the p-values
> from our presets?
>
> Best
>
> Markus
>
>
>> Hi Markus,
>>
>> "Minimum cluster extent" isn't an explicit part of any of the
>> thresholding programs. However, if you're doing cluster-based
>> thresholding in FEAT or with randomise, then the final cluster
>> corrected p-value, when thresholded at say p<0.05, is exactly
>> _equivalent_ to setting a minimum cluster extent (but specified via
>> the corrected p-value, not cluster size) - so you don't have to
>> specify this yourself.
>>
>> Still, better to use TFCE.....
>>
>> Cheers.
>>
>>
>>
>> On 15 Feb 2009, at 16:39, Markus Ploner wrote:
>>
>>> Hi,
>>>
>>> a very simple thresholding question:
>>>
>>> I have a map with uncorrected p-values (e.g. 0.001), a mask for a
>>> priori
>>> defined regions of interest and I assume a minimum cluster extent
>>> (e.g. 10
>>> voxels). How can I calculate which (FDR and FWE)-voxel-corrected p-
>>> value
>>> corresponds to my presets (uncorrected p-value, mask and minimum
>>> cluster
>>> extent)?
>>>
>>> Thanks a lot
>>>
>>> Markus
>>>
>>>
>>>
>>
>>
>> ---------------------------------------------------------------------------
>> 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
>> ---------------------------------------------------------------------------
>>
>>
>
>
> --
> Dr. Markus Ploner
> Humboldt Research Fellow
> FMRIB Centre
> University of Oxford
> Fon 0044-1865-222488
> [log in to unmask]
>
---------------------------------------------------------------------------
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
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