Revealing and quantifying the impaired phonological analysis underpinning impaired comprehension in Wernicke's aphasia.

TitleRevealing and quantifying the impaired phonological analysis underpinning impaired comprehension in Wernicke's aphasia.
Publication TypeJournal Article
Year of Publication2012
AuthorsRobson, H, Keidel, JL, Ralph, MALambon, Sage, KE
JournalNeuropsychologia
Volume50
Issue2
Date Published2012 Jan
Abstract

Wernicke's aphasia is a condition which results in severely disrupted language comprehension following a lesion to the left temporo-parietal region. A phonological analysis deficit has traditionally been held to be at the root of the comprehension impairment in Wernicke's aphasia, a view consistent with current functional neuroimaging which finds areas in the superior temporal cortex responsive to phonological stimuli. However behavioural evidence to support the link between a phonological analysis deficit and auditory comprehension has not been yet shown. This study extends seminal work by Blumstein, Baker, and Goodglass (1977) to investigate the relationship between acoustic-phonological perception, measured through phonological discrimination, and auditory comprehension in a case series of Wernicke's aphasia participants. A novel adaptive phonological discrimination task was used to obtain reliable thresholds of the phonological perceptual distance required between nonwords before they could be discriminated. Wernicke's aphasia participants showed significantly elevated thresholds compared to age and hearing matched control participants. Acoustic-phonological thresholds correlated strongly with auditory comprehension abilities in Wernicke's aphasia. In contrast, nonverbal semantic skills showed no relationship with auditory comprehension. The results are evaluated in the context of recent neurobiological models of language and suggest that impaired acoustic-phonological perception underlies the comprehension impairment in Wernicke's aphasia and favour models of language which propose a leftward asymmetry in phonological analysis.

ISSN Number1873-3514
KeywordsAged, Aged, 80 and over, Aphasia, Wernicke, Auditory Threshold, Comprehension, Discrimination (Psychology), Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Neuroimaging, Neuropsychological Tests, Phonetics, Semantics, Speech Perception
URLhttp://www.ncbi.nlm.nih.gov/pubmed/22172546?dopt=Abstract
DOI10.1016/j.neuropsychologia.2011.11.022
Alternate JournalNeuropsychologia
PubMed ID22172546
Grant ListG0501632 / / Medical Research Council / United Kingdom
MR/J004146/1 / / Medical Research Council / United Kingdom