Knowing what you don't know

language insight in semantic dementia

Sharon A. Savage*, Olivier Piguet, John R. Hodges

*Corresponding author for this work

Research output: Contribution to journalArticle

6 Citations (Scopus)


Background: Reduced insight commonly occurs in dementia and can be specific to one area of functioning. Despite recent models identifying a role for semantic memory, little investigation of insight has been conducted in semantic dementia (SD), with patients often described as being aware of their language problems. Objective: This study aims to investigate language insight in SD. Method: Twenty-two SD (n = 11 severe, n = 11 mild-moderate) and 9 nonfluent primary progressive aphasic patients completed three experimental language tasks to assess knowledge and awareness of certain words. Skills in evaluating language were tested by comparing performance ratings on the Cookie Theft task with objective scoring. Awareness regarding the existence and previous use of certain words was tested using two additional tasks. Results: While SD patients were as accurate as nonfluent patients in rating their own performance on the Cookie Theft immediately following the task, they were significantly poorer at evaluating the same content re-recorded, or other examples of poor language. Compared to nonfluent patients, severe SD patients also made more errors identifying previously known lowfrequency words. Lastly, when tested on labels for specific aspects of an object, only SD patients made errors regarding the existence, or their past knowledge, of certain words. Conclusion: SD patients show a general awareness of their language impairments, but have difficulty evaluating language content. These difficulties adversely affect the ability to reflect upon current and past language skills producing an underawareness of language deficits. This mild, secondary form of anosognosia appears to increase with greater levels of semantic impairment.

Original languageEnglish
Pages (from-to)187-198
Number of pages12
JournalJournal of Alzheimer's Disease
Issue number1
Publication statusPublished - 7 May 2015
Externally publishedYes


  • Anosognosia
  • cognitive awareness
  • frontotemporal dementia
  • primary progressive aphasia
  • self-appraisal

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