OBJECTIVE: We hypothesized that an ERP word repetition paradigm, which reliably elicits and modulates the P600 and N400 components, would be particularly sensitive to the memory deficits and altered synaptic plasticity in mild Alzheimer's disease (AD). The P600 (a late positive component, or 'LPC'), and the N400, are sensitive indices of memory encoding and semantic processing, respectively. METHODS: We studied 11 patients with mild AD (mean MMSE=22.9) and 11 elderly (mean age=77.1) normal controls (NC) on a paradigm in which semantically 'congruous' category statement/exemplar pairs (50%) and 'incongruous' category statement/non-exemplar pairs (50%) repeat at 10-140 s intervals. A minimum of 19 channels ERP data were recorded and submitted to split-plot ANOVAs. RESULTS: Normal ERP data showed: (1) a significant word repetition effect for congruous words, with a wide-spread late positivity between approximately 300 and 800 ms post-stimulus (P600) that is larger for New than Old words; (2) a significant N400 repetition effect for incongruous words, with a right posterior negativity that is reduced for Old relative to New words. By contrast, neither of these word repetition effects was reliably present in the mild AD group. Good group discrimination was achieved by requiring that both these repetition effects were > or = the 10th percentile, with 100% sensitivity and 82% specificity. CONCLUSIONS: We found significant abnormalities of the N400 and P600 in mild AD, with both potentials showing markedly reduced sensitivity to word repetition. SIGNIFICANCE: The absence of normal N400 and LPC/P600 word repetition effects suggests impaired functioning of their neural generators, several of which are located in medial temporal lobe predilection sites (e.g. anterior fusiform, parahippocampal gyrus, hippocampus) for AD/tau pathology.
OBJECTIVE: We hypothesized that an ERP word repetition paradigm, which reliably elicits and modulates the P600 and N400 components, would be particularly sensitive to the memory deficits and altered synaptic plasticity in mild Alzheimer's disease (AD). The P600 (a late positive component, or 'LPC'), and the N400, are sensitive indices of memory encoding and semantic processing, respectively. METHODS: We studied 11 patients with mild AD (mean MMSE=22.9) and 11 elderly (mean age=77.1) normal controls (NC) on a paradigm in which semantically 'congruous' category statement/exemplar pairs (50%) and 'incongruous' category statement/non-exemplar pairs (50%) repeat at 10-140 s intervals. A minimum of 19 channels ERP data were recorded and submitted to split-plot ANOVAs. RESULTS: Normal ERP data showed: (1) a significant word repetition effect for congruous words, with a wide-spread late positivity between approximately 300 and 800 ms post-stimulus (P600) that is larger for New than Old words; (2) a significant N400 repetition effect for incongruous words, with a right posterior negativity that is reduced for Old relative to New words. By contrast, neither of these word repetition effects was reliably present in the mild AD group. Good group discrimination was achieved by requiring that both these repetition effects were > or = the 10th percentile, with 100% sensitivity and 82% specificity. CONCLUSIONS: We found significant abnormalities of the N400 and P600 in mild AD, with both potentials showing markedly reduced sensitivity to word repetition. SIGNIFICANCE: The absence of normal N400 and LPC/P600 word repetition effects suggests impaired functioning of their neural generators, several of which are located in medial temporal lobe predilection sites (e.g. anterior fusiform, parahippocampal gyrus, hippocampus) for AD/tau pathology.
Authors: R D Terry; E Masliah; D P Salmon; N Butters; R DeTeresa; R Hill; L A Hansen; R Katzman Journal: Ann Neurol Date: 1991-10 Impact factor: 10.422
Authors: John M Olichney; Jason R Taylor; Shiaohui Chan; Jin-Chen Yang; Andrew Stringfellow; Dieter G Hillert; Amanda L Simmons; David P Salmon; Vicente Iragui-Madoz; Marta Kutas Journal: Neuropsychologia Date: 2010-04-28 Impact factor: 3.139
Authors: Krishna L Bharani; Ken A Paller; Paul J Reber; Sandra Weintraub; Jorge Yanar; Robert G Morrison Journal: Neuropsychol Dev Cogn B Aging Neuropsychol Cogn Date: 2015-09-30
Authors: John M Olichney; Jason R Taylor; Dieter G Hillert; Shiao-Hui Chan; David P Salmon; James Gatherwright; Vicente J Iragui; Marta Kutas Journal: Neurobiol Aging Date: 2008-12-04 Impact factor: 4.673
Authors: Yang Jiang; Joann Lianekhammy; Adam Lawson; Chunyan Guo; Donald Lynam; Jane E Joseph; Brian T Gold; Thomas H Kelly Journal: Psychiatry Res Date: 2009-06-27 Impact factor: 3.222
Authors: Jin-Chen Yang; Lillian Chi; Sara Teichholtz; Andrea Schneider; Rawi Nanakul; Ralph Nowacki; Andreea Seritan; Bruce Reed; Charles DeCarli; Vicente J Iragui; Marta Kutas; Paul J Hagerman; Randi J Hagerman; John M Olichney Journal: Neuropsychologia Date: 2014-08-09 Impact factor: 3.139
Authors: John M Olichney; Jamie Pak; David P Salmon; Jin-Chen Yang; Tim Gahagan; Ralph Nowacki; Lawrence Hansen; Douglas Galasko; Marta Kutas; Vicente J Iragui-Madoz Journal: Cogn Neurosci Date: 2013-10-04 Impact factor: 3.065
Authors: Lucas S Broster; Shonna L Jenkins; Sarah D Holmes; Matthew G Edwards; Gregory A Jicha; Yang Jiang Journal: Neuropsychologia Date: 2018-05-07 Impact factor: 3.139
Authors: J-C Yang; C Simon; A Schneider; A L Seritan; L Hamilton; P J Hagerman; R J Hagerman; J M Olichney Journal: Genes Brain Behav Date: 2013-12-26 Impact factor: 3.449