The hippocampus supports recognition memory for familiar words but not unfamiliar faces

Curr Biol. 2008 Dec 23;18(24):1932-6. doi: 10.1016/j.cub.2008.10.046. Epub 2008 Dec 11.


Bilateral damage to the human hippocampus profoundly impairs the ability to form long-term, consciously accessible memories, producing a classic amnesic syndrome. However, the effect of hippocampal damage on our ability to recognize items via a feeling of familiarity is hotly disputed. Dual-process theory predicts no effect, whereas declarative memory theory predicts impairment of all types of recognition memory. Here, we demonstrate a striking material specificity in the effect of focal hippocampal damage: Recognition memory is impaired for words but intact for faces. The latter finding is incompatible with declarative memory theory, whereas the former constrains dual-process theory by revealing the limitations of postulated extrahippocampal familiarity-based processes. We suggest that the hippocampus boosts recognition of well-known stimuli (high-frequency words) by activating pre-experimental associations that enrich the context of their presentation. By contrast, recognition memory for some kinds of previously unfamiliar stimuli (unfamiliar faces) may be supported by extrahippocampal familiarity-based processes, at least over short intervals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Auditory Perception / physiology
  • Case-Control Studies
  • Face
  • Female
  • Hippocampus / injuries
  • Hippocampus / physiology*
  • Hippocampus / physiopathology
  • Humans
  • Male
  • Memory / physiology*
  • Models, Neurological
  • Models, Psychological
  • Neuropsychological Tests
  • Speech Acoustics
  • Visual Perception / physiology