Laboratories of Integrative Neuroscience and Cognition, Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA.
J Neurosci. 2011 Jun 22;31(25):9345-52. doi: 10.1523/JNEUROSCI.1448-11.2011.
Converging evidence supports the hypothesis that an anterolateral processing pathway mediates sound identification in auditory cortex, analogous to the role of the ventral cortical pathway in visual object recognition. Studies in nonhuman primates have characterized the anterolateral auditory pathway as a processing hierarchy, composed of three anatomically and physiologically distinct initial stages: core, belt, and parabelt. In humans, potential homologs of these regions have been identified anatomically, but reliable and complete functional distinctions between them have yet to be established. Because the anatomical locations of these fields vary across subjects, investigations of potential homologs between monkeys and humans require these fields to be defined in single subjects. Using functional MRI, we presented three classes of sounds (tones, band-passed noise bursts, and conspecific vocalizations), equivalent to those used in previous monkey studies. In each individual subject, three regions showing functional similarities to macaque core, belt, and parabelt were readily identified. Furthermore, the relative sizes and locations of these regions were consistent with those reported in human anatomical studies. Our results demonstrate that the functional organization of the anterolateral processing pathway in humans is largely consistent with that of nonhuman primates. Because our scanning sessions last only 15 min/subject, they can be run in conjunction with other scans. This will enable future studies to characterize functional modules in human auditory cortex at a level of detail previously possible only in visual cortex. Furthermore, the approach of using identical schemes in both humans and monkeys will aid with establishing potential homologies between them.
越来越多的证据支持这样一种假设，即前外侧处理途径介导了听觉皮层中的声音识别，类似于腹侧皮层途径在视觉物体识别中的作用。非人类灵长类动物的研究已经将前外侧听觉途径描述为一个处理层次结构，由三个在解剖学和生理学上不同的初始阶段组成：核心、带和副带。在人类中，这些区域的潜在同源物在解剖学上已经被确定，但它们之间可靠和完整的功能区别尚未建立。由于这些区域在不同个体中的位置不同，因此需要在单个个体中定义这些区域，以研究猴子和人类之间潜在的同源物。我们使用功能磁共振成像（fMRI）呈现了三类声音（音调、带通噪声爆发和同物种发声），与之前在猴子研究中使用的声音等效。在每个个体受试者中，很容易识别出三个与猕猴核心、带和副带具有功能相似性的区域。此外，这些区域的相对大小和位置与人类解剖学研究报告的结果一致。我们的研究结果表明，人类前外侧处理途径的功能组织在很大程度上与非人类灵长类动物一致。由于我们的扫描时间每个受试者仅为 15 分钟，因此可以与其他扫描同时进行。这将使未来的研究能够以以前在视觉皮层中才有可能达到的细节水平来描述人类听觉皮层中的功能模块。此外，在人类和猴子中使用相同方案的方法将有助于确定它们之间的潜在同源性。
