Convergent Connectivity and Graded Specialization in the Rostral Human Temporal Lobe as Revealed by Diffusion-Weighted Imaging Probabilistic Tractography
Convergent Connectivity and Graded Specialization in the Rostral Human Temporal Lobe as Revealed by Diffusion-Weighted Imaging Probabilistic Tractography
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DOI：
10.1162/jocn_a_00263
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发表时间：
2012-10-01
影响因子：
3.2
通讯作者：
Ralph, Matthew A. Lambon
中科院分区：
文献类型：
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作者：
Binney, Richard J.;Parker, Geoffrey J. M.;Ralph, Matthew A. Lambon
近年来，多项独立的神经科学研究表明，喙侧颞叶在听觉和视觉感知、语言和语义记忆中起着关键作用。虽然出现在不同的认知功能的背景下，其中大多数都表明，有一个逐渐收敛的感觉信息在颞叶，最终在模态和感知不变的表征在最喙的方面。目前，然而，太少的是已知的连接在人类颞叶，以确定到底是如何以及在哪里收敛发生;现有的假设主要是来自跨物种的基础上，从侵入性的非人类灵长类动物的研究，其有效性是不清楚的，特别是在语言功能的关注。在这项研究中，我们映射的连接，人类头侧颞叶在体内首次使用扩散加权成像概率纤维束成像。结果表明，感觉信息在颞叶的会聚实际上是一个分级的过程，沿着其纵轴和横轴发生，并在最吻端达到高潮。我们强调我们的结果与先前的功能神经成像，计算建模和患者研究的一致性。通过超越简单的神经束重建，我们系统地探索了特定的颞叶区域的额叶和顶叶语言区域的连接。与颞叶内连接的分级相反，这种颞叶间的连接被发现在尾侧、中间和喙侧亚区之间分离。此外，我们确定了一个基底喙颞区非常有限的连接到颞叶以外的地区，这与最近的证据表明，该子区域的基础提取模态和上下文不变的语义表示。
In recent years, multiple independent neuroscience investigations have implicated critical roles for the rostral temporal lobe in auditory and visual perception, language, and semantic memory. Although arising in the context of different cognitive functions, most of these suggest that there is a gradual convergence of sensory information in the temporal lobe that culminates in modality- and perceptually invariant representations at the most rostral aspect. Currently, however, too little is known regarding connectivity within the human temporal lobe to be sure of exactly how and where convergence occurs; existing hypotheses are primarily derived on the basis of cross-species generalizations from invasive nonhuman primate studies, the validity of which is unclear, especially where language function is concerned. In this study, we map the connectivity of the human rostral temporal lobe in vivo for the first time using diffusion-weighted imaging probabilistic tractography. The results indicate that convergence of sensory information in the temporal lobe is in fact a graded process that occurs along both its longitudinal and lateral axes and culminates in the most rostral limits. We highlight the consistency of our results with those of prior functional neuroimaging, computational modeling, and patient studies. By going beyond simple fasciculus reconstruction, we systematically explored the connectivity of specific temporal lobe areas to frontal and parietal language regions. In contrast to the graded within-temporal lobe connectivity, this intertemporal connectivity was found to dissociate across caudal, mid, and rostral subregions. Furthermore, we identified a basal rostral temporal region with very limited connectivity to areas outside the temporal lobe, which aligns with recent evidence that this subregion underpins the extraction of modality- and context-invariant semantic representations.