White matter anisotropy in the ventral language pathway predicts sound-to-word learning success.
White matter anisotropy in the ventral language pathway predicts sound-to-word learning success.
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DOI：
10.1523/jneurosci.0999-11.2011
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发表时间：
2011-06-15
期刊：
影响因子：
--
通讯作者：
Wong PC
中科院分区：
文献类型：
--
作者：
Wong FC;Chandrasekaran B;Garibaldi K;Wong PC
According to the dual stream model of auditory language processing, the dorsal stream is responsible for mapping sound to articulation while the ventral stream plays the role of mapping sound to meaning. Most researchers agree that the arcuate fasciculus (AF) is the neuroanatomical correlate of the dorsal steam, however, less is known about what constitutes the ventral one. Nevertheless two hypotheses exist, one suggests that the segment of the AF that terminates in middle temporal gyrus corresponds to the ventral stream and the other suggests that it is the extreme capsule that underlies this sound to meaning pathway. The goal of this study is to evaluate these two competing hypotheses. We trained participants with a sound-to-word learning paradigm in which they learned to use a foreign phonetic contrast for signaling word meaning. Using diffusion tensor imaging (DTI), a brain imaging tool to investigate white matter connectivity in humans, we found that fractional anisotropy in the left parietal-temporal region positively correlated with the performance in sound-to-word learning. In addition, fiber tracking revealed a ventral pathway, composed of the extreme capsule and the inferior longitudinal fasciculus, that mediated auditory comprehension. Our findings provide converging evidence supporting the importance of the ventral steam, an extreme capsule system, in the frontal-temporal language network. Implications for current models of speech processing will also be discussed.
