Hi,
I am after some general advice about reporting SPM activations.
Looking at the literature, it seems like a standard way of describing
one's SPM results is to include the volume cluster summary (Talairach
coordinates, Z scores etc.).
However, for many paradigms, the SPM results can form large connected
clusters which extend over several neuroanatomical areas. I am writing
up just such a study in which I have connected activation in lateral and
medial visual areas together with posterior parietal activation. As far
as SPM is concerned I have one big connected cluster. Of course, SPM
picks out sub-cluster local maxima, but it seems to me that it seems
rather arbritary to pick out these maximal points from an activation map
which is above my statistical threshold (height corrected 0.05) at many
more anatomical positions.
It seems to me that in these kind of cases the cluster summary does not
provide much useful information.
So, my question is:. Does it seem reasonable in these cases to just
describe the activations in terms of which neuro-anatomical areas show
activated voxels within them i.e. can I dispense with the volume summary
altogether (except in the case of smaller discrete clusters)?
I'd be interested in any opinions and I'd especially like to know if
anyone has had trouble with referees over this particular issue.
All the best,
Krish
--
Dr Krish D Singh
Department of Vision Sciences
Aston University
Aston triangle
Birmingham
B4 7ET
ENGLAND
tel: +44 (0)121 359 3611 ext 5176/5190
fax: +44 (0)121-333 4220
email: [log in to unmask]
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