EVENT: Psychology Colloquium: Prof Morrone: Development and Plasticity of Primary visual cortex in human

Department of Translational Research in New Technologies in Medicine and Surgery University of Pisa - Fondazione Stella Maris IRCCS

Maria Concetta Morrone graduated in Physics from the University of Pisa, trained in Biophysics at the elite Scuola Normale Superiore and she is now a Professor of Pshysiology at University of Pisa, Medical School. Over the years her research has spanned most active areas of vision research, including spatial vision, development, plasticity, attention, color, motion, robotics, vision during eye movements and more recently multisensory perception and action. Prof. Morrone has published some 170 publications in excellent international peer-review journals, including Nature and her sister journals, Neuron, Current Biology and Trends in Neuroscience and Trend in Cognitive Neuroscience. She is a member of the Lincei Accademy. She has been editor of several major specialised journals and was one of the founding editors of the journal of vision, and currently she is Chief Editor and founder of the journal "Multisensory Research".

Title: Development and Plasticity of primary visual cortex in human.

The brain is a flexible, and continuously adapts to past experience. In this talk I will give two examples of visual cortical plasticity, during development, and in adult life. Using fMRI, we have demonstrated unexpected maturation of motion direction-sensitivity in young infants. BOLD responses to flow-motion versus random-motion in 7-week- old infants are nearly adult-like in parietal-occipital area, cuneous, posterior parietal and posterior insular cortex, which in adults receives visual-vestibular input. We also have evidence that MT receives independent input from V1 perinatally, and that V1 maturation is delayed respect other cortical visual area. This may help to explain the profound reorganization that we and others have observed in patients with perinatal lesions of optical radiation,where ipsilateral primary cortex codes non only the contralateral but also the ipsilateral visual field. Plastic changes in primary visual cortex are not limited to the developmental period, but can extend through life. We showed strong residual plasticity in the adult human visual cortex, particularly for processes involving competition between ocular inputs. One of the most sensitive measures of the effects of deprivation is binocular rivalry, a form of visual bistability that engages strong competition between monocular signals. surprisingly, short term monocular deprivation results in the deprived eye dominating rivalrous perception, lasting up to 3hr after patch removal.. Our results suggest that monocular deprivation may act to up-regulate contrast gain, resulting in stronger signals from the deprived eye(homeostatic plasticity, contrary to what is thought to occur with patching theraphy). We further show a release of GABAergic inhibition after short deprivation in occipital cortex measured by MR spectroscopy at 7T. In summary, the adult human visual cortex retains a high degree of plasticity using similar molecular mechanisms at core function in modulating plasticity during development.