Mapping Common Aphasia Assessments to Underlying Cognitive Processes and Their Neural Substrates.
Mapping Common Aphasia Assessments to Underlying Cognitive Processes and Their Neural Substrates.
- 2017
Available online from MWHC library: 2006 - 2009, Available in print through MWHC library: 1999 - March 2006
BACKGROUND: Understanding the relationships between clinical tests, the processes they measure, and the brain networks underlying them, is critical in order for clinicians to move beyond aphasia syndrome classification toward specification of individual language process impairments. CONCLUSIONS: An extensive clinical aphasia assessment identifies 4 independent language functions, relying on discrete parts of the left middle cerebral artery territory. A better understanding of the processes underlying cognitive tests and the link between lesion and behavior may lead to improved aphasia diagnosis, and may yield treatments better targeted to an individual's specific pattern of deficits and preserved abilities. METHODS: Twenty-five behavioral tests were administered to a group of 38 chronic left hemisphere stroke survivors and a high-resolution magnetic resonance image was obtained. Test scores were entered into a principal components analysis to extract the latent variables (factors) measured by the tests. Multivariate lesion-symptom mapping was used to localize lesions associated with the factor scores. OBJECTIVE: To understand the cognitive, language, and neuroanatomical factors underlying scores of commonly used aphasia tests. RESULTS: The principal components analysis yielded 4 dissociable factors, which we labeled Word Finding/Fluency, Comprehension, Phonology/Working Memory Capacity, and Executive Function. While many tests loaded onto the factors in predictable ways, some relied heavily on factors not commonly associated with the tests. Lesion symptom mapping demonstrated discrete brain structures associated with each factor, including frontal, temporal, and parietal areas extending beyond the classical language network. Specific functions mapped onto brain anatomy largely in correspondence with modern neural models of language processing.
English
1545-9683
*Aphasia/dg [Diagnostic Imaging]
*Aphasia/pp [Physiopathology]
*Brain Mapping
*Cognition/ph [Physiology]
*Learning/ph [Physiology]
Adult
Aged
Aphasia/et [Etiology]
Executive Function/ph [Physiology]
Factor Analysis, Statistical
Female
Functional Laterality
Humans
Imaging, Three-Dimensional
Magnetic Resonance Imaging
Male
Memory, Short-Term
Middle Aged
Neuropsychological Tests
Regression Analysis
Stroke/co [Complications]
MedStar National Rehabilitation Network
MedStar Washington Hospital Center
Neurology
Journal Article
Available online from MWHC library: 2006 - 2009, Available in print through MWHC library: 1999 - March 2006
BACKGROUND: Understanding the relationships between clinical tests, the processes they measure, and the brain networks underlying them, is critical in order for clinicians to move beyond aphasia syndrome classification toward specification of individual language process impairments. CONCLUSIONS: An extensive clinical aphasia assessment identifies 4 independent language functions, relying on discrete parts of the left middle cerebral artery territory. A better understanding of the processes underlying cognitive tests and the link between lesion and behavior may lead to improved aphasia diagnosis, and may yield treatments better targeted to an individual's specific pattern of deficits and preserved abilities. METHODS: Twenty-five behavioral tests were administered to a group of 38 chronic left hemisphere stroke survivors and a high-resolution magnetic resonance image was obtained. Test scores were entered into a principal components analysis to extract the latent variables (factors) measured by the tests. Multivariate lesion-symptom mapping was used to localize lesions associated with the factor scores. OBJECTIVE: To understand the cognitive, language, and neuroanatomical factors underlying scores of commonly used aphasia tests. RESULTS: The principal components analysis yielded 4 dissociable factors, which we labeled Word Finding/Fluency, Comprehension, Phonology/Working Memory Capacity, and Executive Function. While many tests loaded onto the factors in predictable ways, some relied heavily on factors not commonly associated with the tests. Lesion symptom mapping demonstrated discrete brain structures associated with each factor, including frontal, temporal, and parietal areas extending beyond the classical language network. Specific functions mapped onto brain anatomy largely in correspondence with modern neural models of language processing.
English
1545-9683
*Aphasia/dg [Diagnostic Imaging]
*Aphasia/pp [Physiopathology]
*Brain Mapping
*Cognition/ph [Physiology]
*Learning/ph [Physiology]
Adult
Aged
Aphasia/et [Etiology]
Executive Function/ph [Physiology]
Factor Analysis, Statistical
Female
Functional Laterality
Humans
Imaging, Three-Dimensional
Magnetic Resonance Imaging
Male
Memory, Short-Term
Middle Aged
Neuropsychological Tests
Regression Analysis
Stroke/co [Complications]
MedStar National Rehabilitation Network
MedStar Washington Hospital Center
Neurology
Journal Article