Tomou George, Baltaretu Bianca R, Ghaderi Amirhossein, Crawford J Douglas
Centre for Vision Research, York University, Room 0009A, Lassonde Bldg, Toronto, ON, M3J 1P3, Canada.
Centre for Integrative and Applied Neuroscience, York University, Toronto, Canada.
Sci Rep. 2025 Mar 28;15(1):10683. doi: 10.1038/s41598-025-95568-9.
Visual cortex is thought to show both dorsoventral and hemispheric modularity, but it is not known if the same functional modules emerge spontaneously from an unsupervised network analysis, or how they interact when saccades necessitate increased sharing of spatial information. Here, we address these issues by applying graph theory analysis to fMRI data obtained while human participants decided whether an object's shape or orientation changed, with or without an intervening saccade across the object. BOLD activation from 50 vision-related cortical nodes was used to identify local and global network properties. Modularity analysis revealed three sub-networks during fixation: a bilateral parietofrontal network linking areas implicated in visuospatial processing and two lateralized occipitotemporal networks linking areas implicated in object feature processing. When horizontal saccades required visual comparisons between visual hemifields, functional interconnectivity and information transfer increased, and the two lateralized ventral modules became functionally integrated into a single bilateral sub-network. This network included 'between module' connectivity hubs in lateral intraparietal cortex and dorsomedial occipital areas previously implicated in transsaccadic integration. These results provide support for functional modularity in the visual system and show that the hemispheric sub-networks are modified and functionally integrated during saccades.
视觉皮层被认为具有背腹侧和半球模块化特征，但尚不清楚相同的功能模块是否能从无监督网络分析中自发出现，或者当扫视需要增加空间信息共享时它们是如何相互作用的。在这里，我们通过将图论分析应用于功能磁共振成像（fMRI）数据来解决这些问题，这些数据是在人类参与者判断物体的形状或方向是否改变时获得的，无论是否有跨越物体的中间扫视。来自50个与视觉相关的皮层节点的血氧水平依赖（BOLD）激活被用于识别局部和全局网络特性。模块化分析揭示了注视期间的三个子网络：一个连接涉及视觉空间处理区域的双侧顶叶额叶网络，以及两个连接涉及物体特征处理区域的偏侧枕颞网络。当水平扫视需要在视觉半视野之间进行视觉比较时，功能连通性和信息传递增加，并且两个偏侧腹侧模块在功能上整合为一个单一的双侧子网络。这个网络包括外侧顶内皮层和背内侧枕叶区域中先前涉及跨扫视整合的“模块间”连接枢纽。这些结果为视觉系统中的功能模块化提供了支持，并表明半球子网络在扫视期间被修改并在功能上整合。
