Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States.
Department of Psychology, Northeastern University, Boston, MA, United States.
Prog Neurobiol. 2023 Jan;220:102374. doi: 10.1016/j.pneurobio.2022.102374. Epub 2022 Nov 17.
In humans and non-human primates (NHPs), motion and stereopsis are processed within fine-scale cortical sites, including V2 thick stripes and their extensions into areas V3 and V3A that are believed to be under the influence of magnocellular stream. However, in both species, the relative functional organization (overlapping vs. none overlapping) of these sites remains unclear. Using high-resolution functional MRI (fMRI), we found evidence for two minimally-overlapping channels within human extrastriate areas that contribute to processing motion and stereopsis. Across multiple experiments that included different stimuli (random dots, gratings, and natural scenes), the functional selectivity of these channels for motion vs. stereopsis remained consistent. Furthermore, an analysis of resting-state functional connectivity revealed stronger functional connectivity within the two channels rather than between them. This finding provides a new perspective toward the mesoscale organization of the magnocellular stream within the human extrastriate visual cortex, beyond our previous understanding based on animal models.
在人类和非人类灵长类动物（NHPs）中，运动和立体视知觉是在精细的皮质区域内处理的，包括 V2 厚条纹及其延伸到 V3 和 V3A 区域，这些区域被认为受到大细胞流的影响。然而，在这两种物种中，这些区域的相对功能组织（重叠或不重叠）仍不清楚。使用高分辨率功能磁共振成像（fMRI），我们发现人类外纹状区存在两个最小重叠的通道，这些通道有助于处理运动和立体视知觉。在包括不同刺激（随机点、光栅和自然场景）的多个实验中，这些通道对运动与立体视知觉的功能选择性保持一致。此外，对静息状态功能连接性的分析显示，两个通道内的功能连接性更强，而不是它们之间的功能连接性。这一发现为人类外纹状视觉皮层中大细胞流的中尺度组织提供了一个新的视角，超越了我们以前基于动物模型的理解。
