Department of General Psychology, University of Padova, Padova, Italy.
NatBrainLab, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom; Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom.
Cortex. 2018 Jun;103:224-239. doi: 10.1016/j.cortex.2018.02.016. Epub 2018 Mar 9.
According to the dual-stream theory, the processing of visual information is divided into a ventral pathway mediating object recognition, and a dorsal pathway supporting visuomotor control. Increasing evidence suggests that these streams are not independent, but where this dorsal-ventral stream integration occurs remains unknown. We explored the candidate white matter pathways linking dorsal and ventral visual streams in 30 right-handed participants performing object-oriented hand movements of varying complexity (reaching, grasping and lifting), using advanced diffusion imaging tractography based on the spherical deconvolution and kinematical analysis. We provided for the first time a direct evidence of cross-communication between dorsal and ventral visual streams in humans, through vertical occipital fasciculus and temporo-parietal fibers of the arcuate fasciculus during on-line control of grasping and lifting actions. We showed that individual differences in the microstructure of these cross-talk connections were associated with the variability of the arm deceleration, the grip opening and the grasp accuracy. This study suggests that hand kinematics, in skilled hand actions where high degree of online control is required, is related to the anatomy of the cross-talk networks between dorsal and ventral streams, bringing important insights to the dual-stream theory and the sensorimotor organization of hand actions.
根据双通道理论，视觉信息的处理分为腹侧通路介导的物体识别和背侧通路支持的运动控制。越来越多的证据表明，这些通路并非相互独立的，但背侧-腹侧通路整合发生的位置尚不清楚。我们在 30 名右利手参与者中探索了连接背侧和腹侧视觉流的候选白质通路，他们执行了不同复杂程度的面向物体的手部运动（伸手、抓握和提起），使用了基于球解卷积和运动学分析的先进扩散成像轨迹追踪技术。我们首次提供了人类背侧和腹侧视觉流之间交叉通讯的直接证据，即在抓握和提起动作的在线控制过程中，通过垂直枕束和弓状束的颞顶纤维进行交叉通讯。我们表明，这些交叉连接的微观结构的个体差异与手臂减速、握持张开和抓握精度的可变性有关。这项研究表明，在需要高度在线控制的熟练手部动作中，手部运动学与背侧和腹侧流之间的交叉对话网络的解剖结构有关，为双通道理论和手部运动的感觉运动组织提供了重要的见解。
