Abstract
This study aims to provide convergent understanding of the neural basis of auditory word processing efficiency using a multimodal imaging. We investigated the structural and functional correlates of word processing efficiency in healthy individuals. We acquired two structural imaging (T1-weighted imaging and diffusion tensor imaging) and functional magnetic resonance imaging (fMRI) during auditory word processing (phonological and semantic tasks). Our results showed that better phonological performance was predicted by the greater thalamus activity. In contrary, better semantic performance was associated with the less activation in the left posterior middle temporal gyrus (pMTG), supporting the neural efficiency hypothesis that better task performance requires less brain activation. Furthermore, our network analysis revealed the semantic network including the left anterior temporal lobe (ATL), dorsolateral prefrontal cortex (DLPFC) and pMTG was correlated with the semantic efficiency. Especially, this network acted as a neural efficient manner during auditory word processing. Structurally, DLPFC and cingulum contributed to the word processing efficiency. Also, the parietal cortex showed a significate association with the word processing efficiency. Our results demonstrated that two features of word processing efficiency, phonology and semantics, can be supported in different brain regions and, importantly, the way serving it in each region was different according to the feature of word processing. Our findings suggest that word processing efficiency can be achieved by in collaboration of multiple brain regions involved in language and general cognitive function structurally and functionally.
Highlights
Word processing is a key component of language comprehension
The results showed that regional activity of thalamus was significantly correlated with phonological efficiency (PE) (r = -0.51, p < 0.05) and posterior middle temporal gyrus (pMTG) activity was positively associated with semantic efficiency (SE) (r = 0. 53, p < 0.05) (S4 Fig)
The functional activity of the left thalamus was associated with phonological performance, whereas the level of activity in the left pMTG predicted semantic performance; Individuals with stronger activity in thalamus and less activity in pMTG showed better word processing efficiency
Summary
Word processing is a key component of language comprehension. Accumulating evidence from neurological and functional brain imaging studies has suggested that word processing is involved in the left lateralized large-scale of brain network including frontal, temporal, and parietal regions [1,2,3,4]. For successful comprehension in communication, it requires to retrieve and process word timely, which is described as word processing efficiency. Neural correlates of word processing efficiency efficiency varies across individuals and may be attributed to increase or decrease activity of brain regions in the distributed language network. It is important in our daily communication, the underlying neural mechanisms of word processing efficiency still remain unclear
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
