You need to correct such maps for the increased number of degrees of freedom in HCP data if you want to get a sense of sensitivity. For grayordiante-wise correlation analysis, you can increase SNR using a Wishart Rolloff as described in the supplementary methods of our recent publication:
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature18933.html Peace, Matt. From: <[email protected]<mailto:[email protected]>> on behalf of Daniel <[email protected]<mailto:[email protected]>> Date: Monday, July 25, 2016 at 12:48 PM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: [HCP-Users] SNR regarding resting state fcMRI in the HCP database Dear group, I analysed the SNR of a HCP subject (100206, rfMRI_REST2_LR) and was wondering that the SNR is quite low. Attached you can find the results for the threshold of 30. Using a threshold of 50 all signal disappeared! I am aware that the use of higher spatial resolution results in a lower SNR, however, using a SNR with such a low SNR we previously failed to analyze any variability and even connectivity for instance in and between the left-to-right motor cortex. Can anyone explain in more detail why the HCP SNR is quite low and if this affects data analysis? For instance variability between subjects may decreases but is this an artificial homegenization of subjects? Best regards, Daniel SNR lower thr=30 [cid:[email protected]] _______________________________________________ HCP-Users mailing list [email protected]<mailto:[email protected]> 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 [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
