brainstructures
Character vector indicating which brain structure(s)
to read in: "left" (left cortex), "right" (right cortex)
and/or "subcortical" (subcortex and cerebellum). Can also be
"all" (read all three brain structures), or "existing"
(read all brain structures in the file). Default: "existing".
If a brain structure is indicated but does not exist, a warning will be raised and that brain structure will be skipped.