The Cognitive Neurophysiology Laboratory, Children's Evaluation and Rehabilitation Center, Department of Pediatrics, Albert Einstein College of Medicine, New York, New York 10461, USA.
J Neurosci. 2011 Mar 2;31(9):3400-6. doi: 10.1523/JNEUROSCI.3296-10.2011.
Certain features of objects or events can be represented by more than a single sensory system, such as roughness of a surface (sight, sound, and touch), the location of a speaker (audition and sight), and the rhythm or duration of an event (by all three major sensory systems). Thus, these properties can be said to be sensory-independent or amodal. A key question is whether common multisensory cortical regions process these amodal features, or does each sensory system contain its own specialized region(s) for processing common features? We tackled this issue by investigating simple duration-detection mechanisms across audition and touch; these systems were chosen because fine duration discriminations are possible in both. The mismatch negativity (MMN) component of the human event-related potential provides a sensitive metric of duration processing and has been elicited independently during both auditory and somatosensory investigations. Employing high-density electroencephalographic recordings in conjunction with intracranial subdural recordings, we asked whether fine duration discriminations, represented by the MMN, were generated in the same cortical regions regardless of the sensory modality being probed. Scalp recordings pointed to statistically distinct MMN topographies across senses, implying differential underlying cortical generator configurations. Intracranial recordings confirmed these noninvasive findings, showing generators of the auditory MMN along the superior temporal gyrus with no evidence of a somatosensory MMN in this region, whereas a robust somatosensory MMN was recorded from postcentral gyrus in the absence of an auditory MMN. The current data clearly argue against a common circuitry account for amodal duration processing.
某些物体或事件的特征可以通过多个感觉系统来表示，例如表面粗糙度（视觉、听觉和触觉）、说话者的位置（听觉和视觉）以及事件的节奏或持续时间（通过所有三个主要感觉系统）。因此，可以说这些特性是感觉独立的或非模态的。一个关键问题是，共同的多感觉皮层区域是否处理这些非模态特征，或者每个感觉系统是否包含自己专门用于处理常见特征的区域？我们通过研究听觉和触觉之间的简单持续时间检测机制来解决这个问题；选择这些系统是因为在这两个系统中都可以进行精细的持续时间辨别。人类事件相关电位中的失匹配负波（MMN）成分提供了一种敏感的持续时间处理度量标准，并且已经在听觉和体感研究中独立地引出。我们采用高密度脑电图记录结合颅内硬膜下记录，询问 MMN（由 MMN 表示的精细持续时间辨别）是否无论所探测的感觉模态如何，都是在相同的皮质区域中产生的。头皮记录表明，在不同的感觉之间，MMN 的地形图存在统计学上的差异，这意味着潜在的皮质发生器配置存在差异。颅内记录证实了这些非侵入性发现，表明听觉 MMN 的发生器沿着颞上回分布，而在该区域没有体感 MMN 的证据，而在没有听觉 MMN 的情况下，从中脑后回记录到了强大的体感 MMN。当前的数据清楚地反对非模态持续时间处理的共同电路解释。
