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Exp Brain Res (2017) 235:12971308 DOI 10.1007/s00221-017-4917-4
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Web End = How dothetwo visual streams interact witheach other?
A.D.Milner1,2
Abstract The current consensus divides primate cortical visual processing into two broad networks or streams composed of highly interconnected areas (Milner and Goodale 2006, 2008; Goodale 2014). The ventral stream, passing from primary visual cortex (V1) through to inferior parts of the temporal lobe, is considered to mediate the transformation of the contents of the visual signal into the mental furniture that guides memory, recognition and conscious perception. In contrast the dorsal stream, passing from V1 through to various areas in the posterior parietal lobe, is generally considered to mediate the visual guidance of action, primarily in real time. The brain, however, does not work through mutually insulated subsystems, and indeed there are well-documented interconnections between the two streams. Evidence for contributions from ventral stream systems to the dorsal stream comes from human neuropsychological and neuroimaging research, and indicates a crucial role in mediating complex and exible visuomotor skills. Complementary evidence points to a role for posterior dorsal-stream visual analysis in certain aspects of 3-D perceptual function in the ventral stream. A series of studies of a patient with visual form agnosia has been instrumental in shaping our knowledge of what each stream can achieve in isolation; but it has also helped us to tease apart the relative dependence of parietal visuomotor systems on direct bottom-up visual inputs versus inputs redirected via perceptual systems within the ventral stream.
Received: 12 October 2016 / Accepted: 13 February 2017 / Published online: 2 March 2017 The Author(s) 2017. This article is published with open access at Springerlink.com
Keywords Ventral Dorsal Streams Visual Cortex
Introduction
Otto Creutzfeldt, one of the pre-eminent European neuro-scientists of the post-war period, was a major player in the birth and development of Experimental Brain Research, and indeed succeeded Sir John Eccles as the chief editor from 1976, his stewardship ending only with his premature death in January 1992. In the 1980s, Creutzfeldt published two papers (1981, 1985), in which he recognized the crucial importance of output connections for a full understanding of the functional roles of dierent cortical visual areas.It is of course a truism that all visual processing...