Schroeder Charles E, Foxe John J
Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Rd., Bldg. 37, Orangeburg, NY 10962, USA.
Brain Res Cogn Brain Res. 2002 Jun;14(1):187-98. doi: 10.1016/s0926-6410(02)00073-3.
Two fundamental requirements for multisensory integration are convergence of unisensory (e.g. visual and auditory) inputs and temporal alignment of the neural responses to convergent inputs. We investigated the anatomic mechanisms of multisensory convergence by examining three areas in which convergence occurs, posterior auditory association cortex, superior temporal polysensory area (STP) and ventral intraparietal sulcus area (VIP). The first of these was recently shown to be a site of multisensory convergence and the latter two are more well known as 'classic' multisensory regions. In each case, we focused on defining the laminar profile of response to the unisensory inputs. This information is useful because two major types of connection, feedforward and feedback, have characteristic differences in laminar termination patterns, which manifest physiologically. In the same multisensory convergence areas we also examined the timing of the unisensory inputs using the same standardized stimuli across all recordings. Our findings indicate that: (1) like somatosensory input [J. Neurophysiol., 85 (2001) 1322], visual input is available at very early stages of auditory processing, (2) convergence occurs through feedback, as well as feedforward anatomical projections and (3) input timing may be an asset, as well as a constraint in multisensory processing.
多感官整合的两个基本要求是单感官（如视觉和听觉）输入的汇聚以及对汇聚输入的神经反应的时间对齐。我们通过检查三个发生汇聚的区域，即后听觉联合皮层、颞上多感觉区（STP）和腹侧顶内沟区（VIP），来研究多感官汇聚的解剖学机制。其中第一个区域最近被证明是多感官汇聚的位点，而后两个区域作为“经典”的多感官区域更为人所知。在每种情况下，我们专注于定义对单感官输入的反应的层状分布。这些信息很有用，因为两种主要类型的连接，即前馈和反馈，在层状终止模式上有特征性差异，这在生理上表现出来。在相同的多感官汇聚区域，我们还使用所有记录中相同的标准化刺激来检查单感官输入的时间。我们的研究结果表明：（1）与体感输入一样[《神经生理学杂志》，85（2001）1322]，视觉输入在听觉处理的非常早期阶段就可用，（2）汇聚通过反馈以及前馈解剖投射发生，并且（3）输入时间可能是多感官处理中的一项资产，也是一个限制因素。
