Disparity-defined 3D shape is processed in both the ventral and the dorsal visual stream. The network of cortical areas that is activated during the processing of disparity-defined 3D shape includes, in addition to parietal and premotor areas, three clearly distinct regions in inferotemporal cortex (ITC). To investigate the connectivity of the latter regions, we combined electrical stimulation with fMRI in male macaque monkeys. Electrical stimulation of each of the 3D-structure nodes in ITC mainly elicited increased fMRI activations in the other 3D-structure nodes and more variably in other parts of ventral visual cortex. Importantly, no increased activation was found in parietal areas, nor in PFC, whereas microstimulation in posterior parietal cortex did activate the ITC. Our results indicate that 3D-structure nodes in ITC form a strongly interconnected network, receiving input from parietal areas implicated in 3D-structure processing.

SIGNIFICANCE STATEMENT Previous studies combining electrical microstimulation with functional imaging showed an interconnected set of regions in the ventral stream processing faces or bodies, but is has been unclear whether the same is true for other visual categories. Here the authors show that there is a connected system of stereo-selective regions in inferotemporal cortex, receiving input from parietal areas in the dorsal stream.

视差定义的3D形状在腹侧和背侧视觉流中均得到处理。在视差定义的3D形状的处理过程中激活的皮质区域网络除了顶壁和运动前区域外，还包括颞下皮质（ITC）中三个明显不同的区域。为了研究后面区域的连通性，我们在雄性猕猴中将电刺激与功能磁共振成像相结合。ITC中每个3D结构节点的电刺激主要引起其他3D结构节点中腹侧视觉皮层其他部分的fMRI激活增加。重要的是，在顶叶区域和PFC中均未发现激活增加，而在顶叶后皮质中的微刺激确实激活了ITC。

意义声明先前的研究将电微刺激与功能成像相结合，显示腹侧流加工面或人体中的一组相互连接的区域，但是尚不清楚其他视觉类别是否也是如此。在这里，作者表明在颞下皮质中存在一个立体选择区的连接系统，该系统接收来自背流顶壁区域的输入。