Hi - In the most recent PTN release, all node maps (melodic_IC.dtseries.nii) created with group-ICA are sign-flipped (if necessary) to have positive maximum voxel/greyordinate, and then rescaled so this peak is 1. The values of other voxels across the map will vary from node to node, and the overall map determines the scaling of the node timeseries. So yes different nodes can have different amplitudes, but the scaling (for any given node) is consistent across subjects.
btw it looks like the actual stddev of those two timeseries are not massively different. Cheers. > On 24 Oct 2018, at 23:46, David Hofmann <davidhofma...@gmail.com> wrote: > > Hi all, > > I was taking a look at the ICA (100) node time series and noticed that some > ROIs have relatively large magnitude while others have a smaller magnitude > (see attached pictures). Can someone explain to me how these differences > arise? In other words, is this the "natural" BOLD activity within the ROI or > does it somehow come about through the ICA and does not have any meaning? > > Thanks in advance, > > David > _______________________________________________ > HCP-Users mailing list > HCP-Users@humanconnectome.org > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > > <ROI2.jpg><ROI1.jpg> --------------------------------------------------------------------------- Stephen M. Smith, Professor of Biomedical Engineering Head of Analysis, WIN (FMRIB) Oxford FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK +44 (0) 1865 610470 st...@fmrib.ox.ac.uk http://www.fmrib.ox.ac.uk/~steve --------------------------------------------------------------------------- Stop the cultural destruction of Tibet _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
