Dear Eraldo,
Not if you are trying to compare *only* two clusters (say one from
group/condition A
to one from group/condition B). This is simply because we have good
approximations
of the distribution of the size under the NULL hypothesis but not under
the alternative hypothesis, under which you probably are ...
Of course, things are different if you have more than one estimation of
this
cluster size under gp/cond A and B ... in which case you'd know what to
do ...
very best
jb
>
> Dear Karl and other experts in SPM statistics
>
> It there is a formal way (according to theory of gaussian fields) of
> comparing whether the size (number of voxels over threshold) of two
> clusters is signifcantly different?
>
> Thanks for replying
>
> E. Paulesu
>
> Prof. Eraldo Paulesu
> Università degli Studi di Milano - Bicocca
> Dipartimento di Psicologia
> Piazza dell'Ateneo Nuovo 1
> Edificio U6
> 20126 Milano, Italia
> phone +39 02 6448 6748
> fax +39 02 6448 6705
> *************************************
> Laboratory address
> Centro Ciclotrone/PET
> Scientific Institute H San Raffaele
> via Olgettina 60
> 20132 Milano
> Italia
> phone +39 02 2171 7544
> fax +39 02 2171 7558
>
> Web http://web.tiscalinet.it/epaulesu/
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