Two experiments examined processing of lexical ambiguity in healthy older control (HC), mild cognitive impairment (MCI) and Alzheimer's disease (AD) participants. In Experiment 1, groups of HC, MCI and AD participants took part in an ERP study in which they read lexically ambiguous items presented in a subordinate context and primed by the same item presented in a dominant context. Ambiguous items were homonyms (e.g., bank), metaphorical polysemes (e.g., star), or metonyms (e.g., rabbit). All participants exhibited smaller N400s for items preceded by a related prime. In addition, HC participants exhibited a smaller N400 for metonyms than for metaphorical polysemes or homonyms; this effect was diminished in MCI and AD participants. In Experiment 2, HC and MCI participants completed a primed lexical decision task where targets related to the subordinate meaning/sense of ambiguous items were preceded by primes biasing the dominant meaning/sense (e.g., financial-bank-river). In contrast to the results of Experiment 1, both HC and MCI participants showed priming for metonymic items, but not homonyms or metaphorical polysemes. These results suggest that basic knowledge of multiple senses of metonyms is preserved in MCI, but the processing advantage conveyed by this semantic richness is diminished in MCI and AD.
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http://dx.doi.org/10.1016/j.neuropsychologia.2009.01.028 | DOI Listing |
Neurology
January 2025
Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD.
Background And Objectives: Blood-based biomarkers of amyloid and tau have been shown to predict Alzheimer disease (AD) dementia. Much less is known about their ability to predict risk of mild cognitive impairment (MCI), an earlier disease stage. This study examined whether levels of blood biomarkers of amyloid (Aβ/Aβ ratio), tau (p-tau), neurodegeneration (NfL), and glial activation and neuroinflammation (glial fibrillary acidic protein [GFAP], YKL40, soluble triggering receptor expressed on myeloid cells 2 [sTREM2]) collected when participants were cognitively normal are associated with the time to onset of MCI.
View Article and Find Full Text PDFCNS Neurosci Ther
December 2024
Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China.
Aims: The nucleus basalis of Meynert (NBM) is a major source of cholinergic innervation in the central nervous system. We aimed to investigate the characteristics of structural and functional alterations in the NBM and its projections in patients with mild cognitive impairment (MCI) and the effects of computerized cognitive training (CCT).
Methods: Forty-five patients with MCI and 45 cognitively unimpaired controls (CUCs) were recruited.
Neurol Clin Pract
February 2025
University of Rochester School of Medicine and Dentistry (JS, AV); Center for Health and Technology (CHeT) (JS, JW, AV, SJR, CE, AA, CZ, CRH), University of Rochester; University of Utah Spencer Fox Eccles School of Medicine (SJR); Des Moines University College of Osteopathic Medicine (AA); Department of Biostatistics and Neurology (ND), University of Rochester; Alzheimer's Disease Care, Research and Education Program (AD-CARE) (AM, SS-S, EJS), University of Rochester; and Department of Neurology (CRH), University of Rochester.
Background And Objectives: In preparation for future clinical trials involving individuals with Alzheimer disease (AD), mild cognitive impairment (MCI), and dementia, it is important to ascertain the widespread impact of symptoms from the direct perspectives of patients and caregivers. In this study, we performed cross-sectional surveys using large-scale patient and caregiver data to identify the prevalence and average impact of symptoms and symptomatic themes experienced by adults with AD, MCI, and dementia. Subsequent analyses were used to determine which demographic and disease-specific factors are associated with more severe disease.
View Article and Find Full Text PDFDrug Saf
December 2024
Division of Neurology, Department of Clinical Sciences Lund, Lund University, Box 117, 22100, Lund, Sweden.
Drug-induced cognitive impairment (DICI) is a well-established, yet under-recognised, complication of many types of pharmacological treatment. While there is a large body of scientific literature on DICI, most papers are about drug-induced dementia in the elderly and one specific drug class. However, DICI also comprises subclinical symptoms, domain-specific forms of cognitive impairment as well as mild cognitive impairment (MCI), and delirium.
View Article and Find Full Text PDFIBRO Neurosci Rep
December 2024
Department of Internal medicine and Therapeutics, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana.
Background: The Global prevalence of dementia is projected to rise, particularly in low and middle-income countries like Ghana. Mild cognitive impairment (MCI), an intermediate phase between normal cognitive aging and dementia, is characterized by an objective and subjective decline in cognitive abilities. Individuals with MCI have a greater likelihood of progression to dementia.
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