Data from: Posterior parietal cortex drives inferotemporal activations during three-dimensional object vision

The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D) object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP) during functional magnetic resonance imaging (fMRI) reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC) in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams.灵长类视觉系统包含两条专属通路：专司物体识别的腹侧视觉通路（ventral stream），以及对空间视觉与行为至关重要的背侧视觉通路（dorsal visual stream）。然而，学界对这两条通路之间的相互作用与信息流动仍知之甚少。本研究针对同时涵盖背侧与腹侧通路的三维（3D）物体信息加工网络中的相互作用展开探究。我们在功能磁共振成像（fMRI）过程中对猕猴尾侧顶内区（CIP）进行可逆性失活，结果发现背侧通路的后顶叶皮层的fMRI激活信号显著减弱，令人意外的是，腹侧视觉通路的颞下回皮层（ITC）的激活信号同样出现降低。此外，CIP失活会导致猕猴在深度结构分类任务中产生感知缺陷。fMRI环境下的CIP微刺激实验进一步表明，CIP通过后顶叶区域向腹侧通路的颞下回皮层传递视觉信息。据我们所知，本研究结果首次为背侧通路向腹侧通路传递视觉三维信息提供了因果性证据，并确认CIP是深度结构加工的关键脑区。综上，在fMRI实验中结合可逆性失活与电微刺激技术，能够清晰揭示两条视觉加工通路之间的功能性相互作用。