• Vol. 44 No. 9, 342–349
  • 15 September 2015

Hyperfamiliarity in Dementia and Mild Cognitive Impairment



Download PDF


Introduction: Hyperfamiliarity, a phenomenon in which feelings of familiarity are evoked by novel stimuli, is well described in epilepsy and the lesioned brain. Abnormality of familiarity in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) have also been described in the literature, but more from a neuropsychological approach perspective. Currently, there is a lack of study on the real-life experience of familiarity abnormality in dementia and MCI. Our aim was to compare the occurrence of hyperfamiliarity among dementia and MCI.

Materials and Methods: We recruited 73 participants, 29 with AD, 10 with vascular dementia, 7 with MCI and 27 healthy controls, and administered a questionnaire to assess hyperfamiliarity frequency.

Results: Hyperfamiliarity was observed in real-life in cognitive impairment, but was unrelated to its severity or underlying aetiology

Conclusion: This study highlights the similar rate of occurrence of hyperfamiliarity in the daily life of individuals with cognitive impairment. Future research should examine neuropsychological correlations and mechanisms that contribute to such observations.

Hyperfamiliarity, a phenomenon in which novel stimuli evoke feelings of familiarity, has been described in dementia, temporal lobe epilepsy (TLE) and the lesioned brain. There is currently no universal term for the phenomenon of hyperfamiliarity. Labels have been used to describe spurious feelings of familiarity, including ‘false memory’, ‘false recall’, ‘recognition without identification’ and indeed, ‘hyperfamiliarity’. Predominant theories on the cognitive processes behind hyperfamiliarity are highly similar. These theories postulate that hyperfamiliarity occurs when there is recognition without recollection—that is, though a stimulus is perceived to be familiar (i.e. it is recognised), there is no retrieval for contextual information regarding the stimulus (i.e. there is no recollection). However, the theories differ regarding which parts of the brain are responsible.

This article is available only as a PDF. Please click on “Download PDF” on top to view the full article.