Hi > On 25 Aug 2015, at 18:04, Nomi, Jason <[email protected]> wrote: > > Dear Experts, > > I was just reading in the Smith et al. (2013) paper about correcting for > autocorrelations (footnote 7) and was wondering if there were any type of > corrections you would advise. > > I am aware that I should demean, and then normalize the individual time > series before concatenating across sessions > (https://wiki.humanconnectome.org/display/PublicData/HCP+Users+FAQ - point > 3), but I am wondering if there are any suggestions about mixture-model > corrections or pre whitening. > > I am interested in creating a parcellated connectome using the surface based > data based off of an ROI atlas and was wondering if concerns about > autocorrelations would be a problem when exploring dynamic functional > connections between the ROI time series.
For standard correlations between brain regions you can correct for autocorrelations at the stage of converting r to z - see FSLNets documentation and the PTN HCP data release documentation. For looking into "dynamic" connectivity, the need for, and methods for, correction for autocorrelations would depend on exactly what analysis you are trying to do, and I'm guessing for such analyses there are no established standards for that. Cheers. > > Thanks in advance! > > Jason > > > > > > _______________________________________________ > HCP-Users mailing list > [email protected] > http://lists.humanconnectome.org/mailman/listinfo/hcp-users --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Head of Analysis, Oxford University FMRIB Centre FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 222726 (fax 222717) [email protected] http://www.fmrib.ox.ac.uk/~steve <http://www.fmrib.ox.ac.uk/~steve> --------------------------------------------------------------------------- Stop the cultural destruction of Tibet <http://smithinks.net/> _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
