To investigators who have been using HCP physiological monitoring data:
In preparation for the HCP 900 subjects data release, we have identified previously unknown timing errors in the in the processed physiological log files (e.g., rfMRI_REST1_RL_Physio_log.txt). One known bug in the processing code caused an offset between 25ms and 50ms in the respiratory monitoring data. More critically, some physiological data files created by the Siemens PMU were "malformed" in a manner that was not anticipated by our processing code. These malformed files caused variable offsets in timing, sometimes amounting to hundreds of milliseconds. We have decided to take several steps to remedy these timing issues in HCP physiological monitoring data: . First, we will contact a small group of external "beta testers" to assist with the processing of HCP physiological monitoring information. This group will be asked to review the raw data files created by the Siemens Connectom PMU, and the existing HCP processing code, to help identify and remedy any issues that may result in timing inaccuracies. . Second, we will correct known timing issues for all scans, including those previously released as part of the 500 Subjects data release, those slated for release as part of the 900 Subjects data release, and pulse oximetry data that was collected during diffusion MRI scans. The corrected processed physiological log files will be released in a patch that can be downloaded at some point after the 900 Subjects data release. (We do not yet have a projected release date for this patch.) . Third, we have opted to release the raw physiological monitoring files created by the Siemens PMU. This will allow external researchers to integrate the physiological timing information into their existing processing pipelines. These files will be accompanied by documentation describing known information about the timing and processing of those files. (We do not yet have a projected release date for these files.) Please let us know if you would be interested in helping to beta test the raw physiological data by emailing e...@wustl.edu. Once again, we apologize to any investigators whose research has been impacted by this problem. Best, The WU-Minn HCP Consortium Jennifer Elam, Ph.D. Outreach Coordinator, Human Connectome Project Washington University School of Medicine Department of Anatomy and Neurobiology, Box 8108 660 South Euclid Avenue St. Louis, MO 63110 <tel:314-362-9387> 314-362-9387 <mailto:el...@pcg.wustl.edu> el...@pcg.wustl.edu <http://www.humanconnectome.org> www.humanconnectome.org _______________________________________________ HCP-Users mailing list HCP-Users@humanconnectome.org http://lists.humanconnectome.org/mailman/listinfo/hcp-users
