The relationship between visuospatial perception networks and visual confrontation naming in aphasia

Naming visually presented stimuli is a commonly employed language assessment strategy used in evaluating aphasia in research and clinical settings. Naming problems are a hallmark of aphasia disorders commonly attributed to a variety of phonological properties, such as word class, syllable properties, or frequency of target word use, which contribute to patterns of naming performance in aphasia [1,6,12,18,22,23,51,52,66,77]. However, analysis of the linguistic variables alone fails to explain some observed patterns of naming dysfunction, which are subject to influence from a variety of semantic properties (e.g. prototypicality, imageability, semantic category, etc.) [1,6,12,18,22,23,51,52,66,77] and the specific effects of these semantic properties and the neural networks that subserve them remain relatively understudied. Models of visual confrontation naming performance agree that the features of a visual stimulus that identify it as a known entity with a unique configuration of semantic properties initiates the retrieval of the phonological form of a concept name [22,23]. The visual perception of a stimulus gives rise to a complex of semantic features associated with that stimulus, the particular combination of which distinguish it from other semantically or visually similar stimuli [2,14,22,23]. However, the neural networks responsible for mediating this component of naming performance have been relatively understudied. Reviewing evidence from studies of visuospatial perception (VSP) and aphasia suggests the knowledge of the complex of semantic features associated with a stimulus is stored in distributed networks that include areas active during perception [7,10,12,13,14,24,25,43,51,52,62,67,68]. Moreover,the location of these distributed networks is related to that of the relevant sensory and perceptual networks. For visual stimuli, these areas include networks in the ventral and dorsal visual processing streams-especially in the inferior temporal lobe (IFL) and inferior parietal lobule (IPL), respectively. Thus, performance on naming tasks involving a visual component are likely influenced by the integrity/dysfunction of networks in these areas, thereby explaining some of the naming patterns observed in aphasia.

Grantor dc:publisher

Boston University

Year dc:date.issued

2012

Author dc:creator

• Martin, Aaron D.

Language dc:language.iso

en_US

Dc Identifier Other

(ALMA)contemp

OAI identifier oai:identifier

oai:open.bu.edu:2144/12508