Semantic memory plays a critical role in communication and thought, but advances in the cognitive and neural basis for semantic memory have proven elusive. We propose a novel approach to semantic memory by focusing on generalized quantifiers like """"""""some of the apples"""""""" and """"""""most of the oranges."""""""" Our model of generalized quantifier comprehension includes at least a finite set of simple circuits that represent number knowledge, a working memory device the retains the results of intermediate computations, and a small set of combinatorial operations that manipulate information held in working memory. We map this semantic domain onto a large-scale neural network that includes at least parietal cortex (for number knowledge), inferior frontal cortex (for working memory), and dorsolateral prefrontal cortex (for executive switching). Preliminary computational work, behavioral studies in healthy seniors and patients with focal neurodegenerative diseases, and functional neuroimaging work support these distinctions. Patients with corticobasal degeneration have a fundamental deficit in number knowledge but little other lexical comprehension difficulty, related to parietal atrophy. They are particularly impaired in their comprehension of """"""""first-order quantifiers"""""""" like """"""""some of the X"""""""" that depend crucially on number knowledge; fMRI work in healthy adults relates comprehension of first-order quantifiers to parietal cortex. Frontotemporal dementia and Alzheimer's disease patients have limited working memory and poor switching that are associated with frontal atrophy. They are impaired in their comprehension of """"""""higher-order quantifiers"""""""" like """"""""most of the X"""""""" that, beyond number knowledge, also require working memory and the manipulation of information retained in working memory, fMRI work in healthy adults relates comprehension of higher-order quantifiers to frontal cortex. We propose additional modeling, behavioral, and functional neuroimaging studies in healthy seniors and patients with these neurodegenerative diseases to establish the cognitive and neural contribution of number knowledge, working memory, and executive switching during generalized quantifier comprehension. The results of these studies will provide a novel and important perspective on the neural basis for semantic memory, and will improve diagnostic and prognostic accuracy in patients suffering from dementia. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS044266-03
Application #
7059935
Study Section
Special Emphasis Panel (ZRG1-SSS-R (04))
Program Officer
Sutherland, Margaret L
Project Start
2004-05-01
Project End
2009-04-30
Budget Start
2006-05-01
Budget End
2007-04-30
Support Year
3
Fiscal Year
2006
Total Cost
$729,394
Indirect Cost
Name
University of Pennsylvania
Department
Neurology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Olm, Christopher A; McMillan, Corey T; Irwin, David J et al. (2018) Longitudinal structural gray matter and white matter MRI changes in presymptomatic progranulin mutation carriers. Neuroimage Clin 19:497-506
Wisse, L E M; Adler, D H; Ittyerah, R et al. (2017) Comparison of In Vivo and Ex Vivo MRI of the Human Hippocampal Formation in the Same Subjects. Cereb Cortex 27:5185-5196
Taskesen, E; Mishra, A; van der Sluis, S et al. (2017) Susceptible genes and disease mechanisms identified in frontotemporal dementia and frontotemporal dementia with Amyotrophic Lateral Sclerosis by DNA-methylation and GWAS. Sci Rep 7:8899
Ash, Sharon; Ternes, Kylie; Bisbing, Teagan et al. (2016) Dissociation of quantifiers and object nouns in speech in focal neurodegenerative disease. Neuropsychologia 89:141-152
Healey, Meghan L; Grossman, Murray (2016) Social Coordination in Older Adulthood: A Dual-Process Model. Exp Aging Res 42:112-7
Cousins, Katheryn A Q; York, Collin; Bauer, Laura et al. (2016) Cognitive and anatomic double dissociation in the representation of concrete and abstract words in semantic variant and behavioral variant frontotemporal degeneration. Neuropsychologia 84:244-51
Pustina, Dorian; Coslett, H Branch; Turkeltaub, Peter E et al. (2016) Automated segmentation of chronic stroke lesions using LINDA: Lesion identification with neighborhood data analysis. Hum Brain Mapp 37:1405-21
Irwin, David J; Byrne, Matthew D; McMillan, Corey T et al. (2016) Semi-Automated Digital Image Analysis of Pick's Disease and TDP-43 Proteinopathy. J Histochem Cytochem 64:54-66
Olm, Christopher A; Kandel, Benjamin M; Avants, Brian B et al. (2016) Arterial spin labeling perfusion predicts longitudinal decline in semantic variant primary progressive aphasia. J Neurol 263:1927-38
Grossman, Murray; Irwin, David J (2016) The Mental Status Examination in Patients With Suspected Dementia. Continuum (Minneap Minn) 22:385-403

Showing the most recent 10 out of 180 publications