The dorsal stream contribution to phonological retrieval in object naming

1 Moss Rehabilitation Research Institute, Einstein Healthcare Network, Elkins Park, PA 19027, USA.
Brain (Impact Factor: 9.2). 11/2012; 135(12). DOI: 10.1093/brain/aws300
Source: PubMed


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.

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Available from: Junghoon Kim, Mar 16, 2014
    • "In a voxel-based lesion symptom mapping study, Schwartz and colleagues revealed an association between semantic errors and networks in the left anterior temporal cortex that extend well beyond the classical Wernicke's area [11]. In a separate study, they found a relationship between phonological errors and anterior networks not previously linked to such errors, including the premotor cortex, pre-and post-central gyri, supramarginal gyrus, and even some portions of the posterior temporal and temporoparietal cortices [12]. Such findings have been interpreted by many researchers as evidence for a strong interconnection at both the anatomical and the functional levels between language and short-term memory (STM) in the aphasic brain (Cahana-Amitay & Albert, 2015). "
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    • "Cytoarchitectonically, area Spt falls within area Tpt in the planum temporale/parietal operculum region which is not cellularly characteristic of nearby auditory cortex (Galaburda and Sanides, 1980), but rather shares features with Broca's area (Galaburda, 1982). Lesion-symptom and lesion-parameter mapping work has implicated the temporal– parietal junction in speech repetition (present study and reviewed above), as well as in phonological-level aspects of speech production (Dell et al., 2013; Schwartz et al., 2012). Both functional (Buchsbaum et al., 2001, 2005) and structural connectivity (Isenberg et al., 2012) studies have suggested a tight relation between Spt and the pars opercularis of Broca's area. "
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    • "alysis was impossible . Patients in the apraxic group appear to have frontal and subcortical lesions more often , but our information is too limited to carry out statistical analyses . Voxel - based symptom - lesion mapping should be used by future studies to distinguish lesion sites in patients with different types of sound errors ( e . g . , see Schwartz et al . , 2012 , for a dis - tinction between phonological and semantic errors ) ."
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