The Short Version
The claim aligns with the dominant scientific definition of "SuperAgers" — adults 80 and older whose episodic memory performance on standardized tests matches that of people 20 to 30 years younger. Multiple peer-reviewed studies and the Northwestern SuperAging Program confirm this benchmark. However, the phrase "cognitive function" is broader than what the research actually measures; the demonstrated equivalence is primarily in episodic memory (delayed word recall), not across all cognitive domains such as processing speed or executive function.