Loads every subject PEB found by dcm_peb_files and normalises
MATLAB structs to native R-list shape.
dcm_peb_load(peb_dir, subjects = NULL)List with pebs (named list of PEB structures),
subjects, and files.
Reading .mat files requires the R.matlab package. It is listed
in Suggests, so install it only if you have MATLAB PEBs to read;
.rds input needs nothing extra.
dcm_peb_of_pebs, which calls this.