Contribution of the Dorsal and Ventral Visual Streams to the Control of Grasping

Since 1982 Ungerleider and Mishkin's paper about the different roles of dorsal and ventral visual streams, the first as "where" and the last as "what", there is no consensus, what these pathways really do and are they really exist. In this review the contribution of parietal, premotor and prefrontal cortical regions in the control of grasping in the context of the existence of two visual streams is discussed. There is evidence that each of the two streams consists of two subdivisions. The roles of the subdivisions in control of grasping such as: the memorizing of the features of object for grasping, the calculation of value of the object for grasping, the control of the movement's precision, the retention of the movement's goal in working memory, and so on, are analyzed. The complementarity of the dorsal and ventral regions of visual pathways in motion control is shown. The separate problem is the coherency of the execution of all this tasks. Each of the pathways performs its part by interchanging signals and ensuring coordinated execution of the work.