There is more unstructured noise in HCP data because of small voxel size and fast TR. Basically that means the ratio between the neural signal and the random noise is lower and that leads to lower correlation coefficients.
Peace, Matt. From: <hcp-users-boun...@humanconnectome.org<mailto:hcp-users-boun...@humanconnectome.org>> on behalf of Amin Dadashi <amin.dada...@uni-tuebingen.de<mailto:amin.dada...@uni-tuebingen.de>> Date: Monday, July 9, 2018 at 4:14 AM To: hcp-users <hcp-users@humanconnectome.org<mailto:hcp-users@humanconnectome.org>> Subject: [HCP-Users] Brainstem to cortex baseline r-value Dear HCP users, Recently, I have tried to calculate the zero-order correlation between some brainstem ROIs and the cortical vertices. Looking at the mean subjects' correlation map, the connectivity pattern totally makes sense. Even after doing the statistical testing (using permutation based on maximum t-statistics) the significant correlated clusters are located in the expected areas. However, the magnitude of the correlation coefficients are very small (in the order of 0.05 for the peak vertices in the mean map). I have also done the volume-based voxel-wise analysis for the same brainstem ROIs and I had similar findings there. Is there any explanation for such small r-values even though the significant correlations seem to be meaningful? Thank you all, Amin _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org<mailto:HCP-Users@humanconnectome.org> http://lists.humanconnectome.org/mailman/listinfo/hcp-users ________________________________ The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail. _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
