This file was created by the Typo3 extension sevenpack version 0.7.14 --- Timezone: CEST Creation date: 2013-06-20 Creation time: 06-52-13 --- Number of references 4 article 6155 Cerebral Cortex 2010 8 20 8 1946-1954 The processing of color and form is largely segregated within the visual brain. But there is also evidence to suggest that these features are coded in combination early in visual processing. Here, we combined high-resolution functional magnetic resonance imaging (fMRI) together with multivariate pattern classification to examine where in the visual cortex specific color form "conjunctions" are represented. Human subjects viewed visual displays containing colored spiral patterns. The spiral patterns could be red or green, and oriented either clockwise or counterclockwise, leading to 4 possible stimulus configurations. Two additional displays combined 2 of the above single color-form pairings, leading to double conjunctions. We applied linear classifiers to voxel activation patterns obtained while subjects viewed such displays. Our findings not only show that color and form information is coded across retinotopically defined visual areas, but also that the 2 double-conjunction stimuli can be distinguished. The voxels most informative about conjunctions were distinct from those most informative about color or form alone. Our results indicate that conjunctions of form and color may be coded by separate functional units as early as primary visual cortex. The results of this study have implications for theories concerning the segregation and binding of color and form information. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis http://cercor.oxfordjournals.org/cgi/reprint/bhp265v1 Biologische Kybernetik Max-Planck-Gesellschaft en 10.1093/cercor/bhp265 seymourKSeymour colincCWGClifford nikosNKLogothetis abartelsABartels article 5627 Current Biology 2009 2 19 3 177-183 Background. Colour and motion serve as the prime examples of segregated processing in the visual brain, giving rise to the question how colour-motion conjunctions are represented. This problem is also known as the ‘binding problem’. Results. Human volunteers viewed visual displays containing coloured dots rotating around the centre. The dots could be red or green, and rotate clockwise or counter-clockwise, leading to four possible stimulus displays. Superimposed pairs of such stimuli provided two additional displays, each containing both colours and both directions of motion, but differing in their feature-conjunctions. We applied multivariate classifiers to voxel activation patterns obtained whilst subjects viewed such displays. Our analyses confirm the presence of directional motion information across visual cortex, and provide evidence of hue coding in all early visual areas except V5/MT+. Within each cortical area, information on colour and motion appeared to be coded in distinct sets of voxels. Furthermore, our results demonstrate the explicit representation of feature conjunctions in primary visual cortex and beyond. Conclusions. The results show that conjunctions can be de-coded from spatial activation patterns already in V1, indicating an explicit coding of conjunctions at early stages of visual processing. Our findings raise the possibility that the solution of what has been taken as the prime example of the binding problem engages neural mechanisms as early as V1. http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis http://www.sciencedirect.com/science/article/pii/S0960982209005442 Biologische Kybernetik Max-Planck-Gesellschaft en 10.1016/j.cub.2008.12.050 seymourKSeymour colincCWGClifford nikosNKLogothetis abartelsABartels poster 5288 2008 7 http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis Biologische Kybernetik Max-Planck-Gesellschaft Brisbane, Australia Asia-Pacific Conference on Vision (APCV 2008) seymourKSeymour CClifford nikosNLogothetis abartelsABartels poster 5287 NeuroImage 2008 6 41 Supplement 1 S147 http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de http://www.kyb.tuebingen.mpg.de Department Logothetis Biologische Kybernetik Max-Planck-Gesellschaft Melbourne, Australia 14th Annual Meeting of the Organisation for Human Brain Mapping (HBM 2008) seymourKSeymour CClifford nikosNLogothetis abartelsABartels