title: Functional connectivity of visual cortex in the blind follows retinotopic organization principles.
abstract: Is visual input during critical periods of development crucial for the emergence of the fundamental topographical mapping of the visual cortex? And would this structure be retained throughout life-long blindness or would it fade as a result of plastic, use-based reorganization? We used functional connectivity magnetic resonance imaging based on intrinsic blood oxygen level-dependent fluctuations to investigate whether significant traces of topographical mapping of the visual scene in the form of retinotopic organization, could be found in congenitally blind adults. A group of 11 fully and congenitally blind subjects and 18 sighted controls were studied. The blind demonstrated an intact functional connectivity network structural organization of the three main retinotopic mapping axes: eccentricity (centre-periphery), laterality (left-right), and elevation (upper-lower) throughout the retinotopic cortex extending to high-level ventral and dorsal streams, including characteristic eccentricity biases in face- and house-selective areas. Functional connectivity-based topographic organization in the visual cortex was indistinguishable from the normally sighted retinotopic functional connectivity structure as indicated by clustering analysis, and was found even in participants who did not have a typical retinal development in utero (microphthalmics). While the internal structural organization of the visual cortex was strikingly similar, the blind exhibited profound differences in functional connectivity to other (non-visual) brain regions as compared to the sighted, which were specific to portions of V1. Central V1 was more connected to language areas but peripheral V1 to spatial attention and control networks. These findings suggest that current accounts of critical periods and experience-dependent development should be revisited even for primary sensory areas, in that the connectivity basis for visual cortex large-scale topographical organization can develop without any visual experience and be retained through life-long experience-dependent plasticity. Furthermore, retinotopic divisions of labour, such as that between the visual cortex regions normally representing the fovea and periphery, also form the basis for topographically-unique plastic changes in the blind.
authors: 1 Department of Medical Neurobiology, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 2 Department of Psychology, Harvard University, Cambridge, MA 02138 USA striemamit@fas.harvard.edu amira@ekmd.huji.ac.il.
authors: Ella
authors: E
authors: Striem-Amit
authors: 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors: Smadar
authors: S
authors: Ovadia-Caro
authors: 2 Department of Psychology, Harvard University, Cambridge, MA 02138 USA 5 Centre for Mind/Brain Sciences, Università degli Studi di Trento, Polo di Rovereto, Italy.
authors: Alfonso
authors: A
authors: Caramazza
authors: 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors: Daniel S
authors: DS
authors: Margulies
authors: 3 Mind and Brain Institute, Berlin School of Mind and Brain, Humboldt University, Berlin, Germany 4 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
authors: Arno
authors: A
authors: Villringer
authors: 1 Department of Medical Neurobiology, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 6 The Edmond and Lily Safra Centre for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem 91220, Israel 7 Cognitive Sciences Program, The Hebrew University of Jerusalem, Jerusalem 91220, Israel 8 Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, UMR_S 968, Paris, F-75012, France striemamit@fas.harvard.edu amira@ekmd.huji.ac.il.
authors: Amir
authors: A
authors: Amedi
mesh_terms: D000328:Adult; D001766:Blindness / Q000503:physiopathology*; D016022:Case-Control Studies; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D055815:Young Adult
keywords: blindness; development; plasticity; vision