title: The dorsal stream contribution to phonological retrieval in object naming.
abstract: Meaningful speech, as exemplified in object naming, calls on knowledge of the mappings between word meanings and phonological forms. Phonological errors in naming (e.g. GHOST named as 'goath') are commonly seen in persisting post-stroke aphasia and are thought to signal impairment in retrieval of phonological form information. We performed a voxel-based lesion-symptom mapping analysis of 1718 phonological naming errors collected from 106 individuals with diverse profiles of aphasia. Voxels in which lesion status correlated with phonological error rates localized to dorsal stream areas, in keeping with classical and contemporary brain-language models. Within the dorsal stream, the critical voxels were concentrated in premotor cortex, pre- and postcentral gyri and supramarginal gyrus with minimal extension into auditory-related posterior temporal and temporo-parietal cortices. This challenges the popular notion that error-free phonological retrieval requires guidance from sensory traces stored in posterior auditory regions and points instead to sensory-motor processes located further anterior in the dorsal stream. In a separate analysis, we compared the lesion maps for phonological and semantic errors and determined that there was no spatial overlap, demonstrating that the brain segregates phonological and semantic retrieval operations in word production.
authors.affiliation: Moss Rehabilitation Research Institute, 50 Township Line Road, Elkins Park, PA 19027, USA. mschwart@einstein.edu
authors.forename: Myrna F
authors.initials: MF
authors.lastname: Schwartz
authors.forename: Olufunsho
authors.initials: O
authors.lastname: Faseyitan
authors.forename: Junghoon
authors.initials: J
authors.lastname: Kim
authors.forename: H Branch
authors.initials: HB
authors.lastname: Coslett
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001037:Aphasia / Q000150:complications / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D032882:Comprehension; D004192:Discrimination, Psychological; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology; D009483:Neuropsychological Tests; D010700:Phonetics; D011930:Reaction Time; D012660:Semantics; D014706:Verbal Learning / Q000502:physiology