Dear Peter
Thanks for the input. But I was using SPM12b (ver 5268) for the DCM
analyses. Sorry, I should have mentioned that in my original post. Perhaps
the bug from the earlier version of SPM8 was not fixed in SPM12b ver 5268?
I've just noticed that the latest version of SPM12b - ver 5441 (24th April
2013) - is now available. I'll try re-running the post hoc DCM analysis
with that and will let you know if the problem has gone.
Best wishes,
Anthony
On 03/05/2013 09:26, "Zeidman, Peter" <[log in to unmask]> wrote:
>Dear Anthony,
>I have a feeling this may relate to a bug which has been fixed in the
>latest update of SPM8. Please could you download the update dated
>04-Feb-2013 and see if that fixes the problem? You will need to recompute
>your results.
>
>Updates are at http://www.fil.ion.ucl.ac.uk/spm/software/spm8/#Updates .
>
>Best,
>Peter.
>
>> -----Original Message-----
>> From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
>> On Behalf Of Anthony Atkinson
>> Sent: 02 May 2013 11:43
>> To: [log in to unmask]
>> Subject: [SPM] Interpretation of DCM post hoc network discovery results
>>
>> Dear DCM experts
>>
>> I am puzzled about the relationships between certain parts of the
>> output produced by the DCM post hoc network discovery function
>> (spm_dcm_post_hoc). In particular, the graphs of the connectivity
>> structure that are produced (in anatomical and functional spaces) do
>> not seem to correspond to the network that is represented by the
>> Bayesian parameter average values (from DCM.Ep stored in DCM_BPA.mat)
>> and their associated posterior probabilities (from DCM.Pp stored in
>> DCM_BPA.mat). For the DCM post hoc analysis that I ran, I got graphs
>> that show a connectivity structure that has many more connections
>> between nodes than the number of connections identifiable from the
>> DCM.Ep.A and DCM.Ep.B matrices combined (i.e. the connections with non-
>> zero BPA values and non-zero posterior probabilities).
>>
>> Could someone please help clarify this for me?
>>
>> Regards,
>>
>> Anthony
>
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