视觉皮层中运动与形态的相互作用——一种神经模型。
Interactions of motion and form in visual cortex - A neural model.
作者信息
Beck Cornelia, Neumann Heiko
机构信息
Institute for Neural Information Processing, University of Ulm, Germany.
出版信息
J Physiol Paris. 2010 Jan-Mar;104(1-2):61-70. doi: 10.1016/j.jphysparis.2009.11.005. Epub 2009 Nov 10.
In this work, we present a neural model simulating parts of the motion and the form pathway of the visual cortex. It is shown how the visual features motion, disparity, and form that are represented in a distributed way in areas V1, V2, and MT mutually interact at several levels. Thus, their information is shared without the need of explicit neural representation for each combination of features. In particular, we address the issue of 2D extrinsic motion cues generated at occlusions that have to be treated differently than 2D intrinsic motion features of the same object. We suggest that here information of the form channel, namely the indication of a junction, is necessary to achieve a correct percept in the motion pathway. Furthermore, we investigated the question of how a percept of either pattern or component motion is generated in a scenario of moving bars that only differs in the presence or absence of occlusions, like in the chopstick and the barberpole display. We propose different roles for various kinds of MT cells that are involved in the interactions with the form pathway, simulating purely integrative cells tuned to motion and to motion and stereo, but also contrast cells responding strongly when motion in the surround is in the opposite direction. The model simulations reproduce psychophysical and neurophysiological results of the chopstick as well as of the barberpole illusion. The temporal course of the dominant motion percept generated by the iterative interplay between motion and form pathway is in line with data of ocular following responses in primates and humans.
在这项工作中,我们展示了一个模拟视觉皮层运动和形态通路部分的神经模型。展示了在V1、V2和MT区域以分布式方式表示的视觉特征——运动、视差和形态如何在多个层面相互作用。因此,它们的信息得以共享,而无需为每个特征组合进行明确的神经表征。特别是,我们解决了在遮挡处产生的二维外在运动线索的问题,这些线索必须与同一物体的二维内在运动特征区别对待。我们认为,在这里,形态通道的信息,即交点的指示,对于在运动通路中实现正确的感知是必要的。此外,我们研究了在仅在有无遮挡方面存在差异的移动条纹场景中,如筷子和理发店旋转招牌展示中,如何产生图案或成分运动感知的问题。我们提出了参与与形态通路相互作用的各种MT细胞的不同作用,模拟了纯粹调谐到运动、运动和立体视觉的整合细胞,以及当周围运动方向相反时强烈反应的对比细胞。模型模拟再现了筷子以及理发店旋转招牌错觉的心理物理学和神经生理学结果。由运动和形态通路之间的迭代相互作用产生的主导运动感知的时间进程与灵长类动物和人类的眼球跟踪反应数据一致。