Feedback Contributions to Visual Awareness in Human Occipital Cortex Export

@article{citeulike:2064535, abstract = {It has traditionally been assumed that processing within the visual system proceeds in a bottom-up, feedforward manner from retina to higher cortical areas [1]. In addition to feedforward processing, it is now clear that there are also important contributions to sensory encoding that rely upon top-down, feedback (reentrant) projections from higher visual areas to lower ones [2]. By utilizing transcranial magnetic stimulation (TMS) in a metacontrast masking paradigm [3], we addressed whether feedback processes in early visual cortex play a role in visual awareness. We show that TMS of visual cortex, when timed to produce visual suppression of an annulus serving as a metacontrast mask, induces recovery of an otherwise imperceptible disk. In addition to producing disk recovery, TMS suppression of an annulus was greater when a disk preceded it than when an annulus was presented alone. This latter result suggests that there are effects of the disk on the perceptibility of the subsequent mask that are additive and are revealed with TMS of the visual cortex. These results demonstrate spatial and temporal interactions of conscious vision in visual cortex and suggest that a prior visual stimulus can influence subsequent perception at early stages of visual encoding via feedback projections [4].}, author = {Ro, Tony and Breitmeyer, Bruno and Burton, Philip and Singhal, Neel S. and Lane, David}, citeulike-article-id = {2064535}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/S0960-9822(03)00337-3}, citeulike-linkout-1 = {http://www.sciencedirect.com/science/article/B6VRT-48W8P8S-S/2/b88843a4270891698badadead1e4fd7d}, day = {17}, doi = {10.1016/S0960-9822(03)00337-3}, journal = {Current Biology}, keywords = {consciousness, early-vision, feedback}, month = {June}, number = {12}, pages = {1038--1041}, posted-at = {2007-12-06 03:41:01}, priority = {3}, title = {Feedback Contributions to Visual Awareness in Human Occipital Cortex}, url = {http://dx.doi.org/10.1016/S0960-9822(03)00337-3}, volume = {13}, year = {2003} }

TY - JOUR ID - citeulike:2064535 L3 - citeulike-article-id:2064535 N2 - It has traditionally been assumed that processing within the visual system proceeds in a bottom-up, feedforward manner from retina to higher cortical areas [1]. In addition to feedforward processing, it is now clear that there are also important contributions to sensory encoding that rely upon top-down, feedback (reentrant) projections from higher visual areas to lower ones [2]. By utilizing transcranial magnetic stimulation (TMS) in a metacontrast masking paradigm [3], we addressed whether feedback processes in early visual cortex play a role in visual awareness. We show that TMS of visual cortex, when timed to produce visual suppression of an annulus serving as a metacontrast mask, induces recovery of an otherwise imperceptible disk. In addition to producing disk recovery, TMS suppression of an annulus was greater when a disk preceded it than when an annulus was presented alone. This latter result suggests that there are effects of the disk on the perceptibility of the subsequent mask that are additive and are revealed with TMS of the visual cortex. These results demonstrate spatial and temporal interactions of conscious vision in visual cortex and suggest that a prior visual stimulus can influence subsequent perception at early stages of visual encoding via feedback projections [4]. IS - 12 JF - Current Biology EP - 1041 TI - Feedback Contributions to Visual Awareness in Human Occipital Cortex VL - 13 SP - 1038 KW - consciousness KW - early-vision KW - feedback AU - Ro, Tony AU - Breitmeyer, Bruno AU - Burton, Philip AU - Singhal, Neel AU - Lane, David PY - 2003/06/17/ UR - http://dx.doi.org/10.1016/S0960-9822(03)00337-3 ER -