Apologies: I've had to temporarily delete DMCC13benchmark from OpenNeuro. We plan to upload a new version ASAP. The images and associated data in the new version will be the same, and I will keep the same dataset name.
The problem was with the subject ID codes: some of the DMCC participants were members of the Young Adult HCP, and we released DMCC13benchmark with those HCP ID codes. In consultation with members of the HCP we decided that it would be most appropriate to release data with unique ID codes instead. The subject key (linking the subject IDs released on openneuro to the actual HCP ID codes) is available via the HCP ConnectomeDatabase for people who have accepted the HCP data use terms (ConnectomeDB00026, titled "DMCC (Dual Mechanisms of Cognitive Control) subject key").
Again, I apologize for any inconvenience. We are working to upload a corrected version of DMCC13benchmark soon. Please contact me with questions or if you need something sooner; I will add links to this post when DMCC13benchmark is again public.
UPDATE 4 January 2021: The corrected version of DMCC13benchmark is now available as openneuro dataset ds003452, doi: 10.18112/openneuro.ds003452.v1.0.1. We ask anyone using the dataset to use this version (all subject IDs
starting with "f") rather than the previous. Every file should be identical between the versions, excepting the subject IDs.
I again apologize for any inconvenience this change may have caused you, and urge you to contact me with any questions or concerns.