Wernicke's aphasia reflects a combination of acoustic-phonological and semantic control deficits: a case-series comparison of Wernicke's aphasia, semantic dementia and semantic aphasia.

TitleWernicke's aphasia reflects a combination of acoustic-phonological and semantic control deficits: a case-series comparison of Wernicke's aphasia, semantic dementia and semantic aphasia.
Publication TypeJournal Article
Year of Publication2012
AuthorsRobson, H, Sage, KE, Ralph, MALambon
JournalNeuropsychologia
Volume50
Issue2
Date Published2012 Jan
Abstract

Wernicke's aphasia (WA) is the classical neurological model of comprehension impairment and, as a result, the posterior temporal lobe is assumed to be critical to semantic cognition. This conclusion is potentially confused by (a) the existence of patient groups with semantic impairment following damage to other brain regions (semantic dementia and semantic aphasia) and (b) an ongoing debate about the underlying causes of comprehension impairment in WA. By directly comparing these three patient groups for the first time, we demonstrate that the comprehension impairment in Wernicke's aphasia is best accounted for by dual deficits in acoustic-phonological analysis (associated with pSTG) and semantic cognition (associated with pMTG and angular gyrus). The WA group were impaired on both nonverbal and verbal comprehension assessments consistent with a generalised semantic impairment. This semantic deficit was most similar in nature to that of the semantic aphasia group suggestive of a disruption to semantic control processes. In addition, only the WA group showed a strong effect of input modality on comprehension, with accuracy decreasing considerably as acoustic-phonological requirements increased. These results deviate from traditional accounts which emphasise a single impairment and, instead, implicate two deficits underlying the comprehension disorder in WA.

ISSN Number1873-3514
KeywordsAged, Aged, 80 and over, Aphasia, Aphasia, Wernicke, Comprehension, Female, Frontotemporal Lobar Degeneration, Humans, Male, Middle Aged, Neuropsychological Tests, Psycholinguistics, Semantics, Severity of Illness Index, Speech Perception, Temporal Lobe, Visual Perception
DOI10.1016/j.neuropsychologia.2011.11.021
Alternate JournalNeuropsychologia
PubMed ID22178742
Grant ListG0501632 / / Medical Research Council / United Kingdom
MR/J004146/1 / / Medical Research Council / United Kingdom