title: Successful verbal retrieval in elderly subjects is related to concurrent hippocampal and posterior cingulate activation.
abstract: OBJECTIVE
  Memory decline and hippocampal atrophy are two major aspects of Alzheimer's disease. Using a response-related fMRI design, we investigated the relationship between successful verbal retrieval and concurrent cerebral activation in elderly subjects in different stages of cognitive decline. We chose a correlational over the more traditional categorical approach to increase the power of detecting relevant activations.
  
  
  METHODS
  Eleven subjects with Alzheimer's disease, 21 elderly subjects with mild cognitive impairment, and 29 age-matched cognitively unimpaired subjects learned 180 nouns. While measuring brain activation with fMRI, the subjects had to classify these 180 learned plus 180 new distractor words as known or new. Response-related fMRI analysis was used to identify cerebral activation by correctly remembered words (hits) that correlated with retrieval success in the whole group.
  
  
  RESULTS
  Successful verbal retrieval was significantly correlated with concurrent activation of the left hippocampus and posterior cingulate gyrus.
  
  
  CONCLUSIONS
  The study confirms the importance of adequate hippocampal function for successful verbal retrieval in the elderly. In addition, our study supports connectivity studies indicating a functional relationship between the hippocampus and the posterior cingulate gyrus during successful verbal retrieval in the elderly in different stages of cognitive decline.
authors.affiliation: Department of Psychiatry, University of Birmingham, Birmingham, UK. r.heun@bham.ac.uk
authors.forename: Reinhard
authors.initials: R
authors.lastname: Heun
authors.forename: Katrin
authors.initials: K
authors.lastname: Freymann
authors.forename: Michael
authors.initials: M
authors.lastname: Erb
authors.forename: Dirk T
authors.initials: DT
authors.lastname: Leube
authors.forename: Frank
authors.initials: F
authors.lastname: Jessen
authors.forename: Tilo T
authors.initials: TT
authors.lastname: Kircher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Grodd
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology / Q000523:psychology; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology / Q000502:physiology*; D006624:Hippocampus / Q000473:pathology / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D021641:Recognition, Psychology / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology