I know I’ve seen you before: Distinguishing recent-single-exposure-based familiarity from pre-existing familiarity

•Subjects can divide pre-existing memory recall into recollection and familiarity.•Neural differences in recent-single-exposure-based and pre-existing familiarity.•Familiarity types were differentiated in whole-brain and MTL substructures.•These familiarity types led to differing MTL substructure function-correlations.