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Visual perception involves a complex interaction between feedforward and feedback processes. A mechanistic understanding of these processing, and its limitations, is a necessary first step towards elucidating key aspects of perceptual functions and dysfunctions. In this talk, I will review our ongoing effort towards the understanding of how feedback visual processing operates at the level of the thalamus, a dynamic relay station halfway between the retina and the cortex. I will present experimental evidence from several recent electrophysiology studies performed on subjects engaged in visual detection tasks. The results show that modulatory driving provided by top-down processes (the feedback from primary visual cortex) critically influences the ongoing thalamic activity and shapes the message to be delivered to the cortex. When neuromodulatory techniques (Transcranial Magnetic Stimulation or static magnetic fields) are used to transiently disrupt cortical activity two very interesting effects show up: (1) alterations in stimulus detection and (2) the spatial properties of thalamic receptive fields are dramatically modified. Finally, I will show how sensory information can be a powerful tool to interact with the motor system and re-organize altered patterns of movement in neurological disorders such as Parkinson's disease.
Prof. Javier Cudeiro (University of A Coruña and The Centre for Brain Stimulation of Galicia)
Professor
Javier Cudeiro Mazaira holds a degree in Medicine and Surgery from the University of Santiago de Compostela and a Doctorate in Medicine from the same University. Dr. Cudeiro completed his training in neurophysiology at the University of London and obtained a Master degree in Physiology and Sleep Medicine at the University Pablo de Olavide (Spain). Currently he is full Professor of Physiology at the University of A Coruña. His research career has been developed in Spain (Universities of Santiago de Compostela and A Coruña), Germany (University of Marburg), England (Institute of Ophthalmology of London) and U.S (Harvard University and MIT). He has been President of the Spanish Society of Physiological Sciences, and member of the Communication Committee of the European Federation of Neuroscience Societies. Dr. Cudeiro is a member of the Royal Academy of Medicine of Galicia, member of the European Dana Alliance for the Brain, affiliated member of the Berenson-Allen Center for Noninvasive Brain Stimulation (Harvard) and President-elect of the Spanish Society of Neuroscience . He has received the 2001 APMIB Foundation National Research Prize, was awarded the 2004 Infanta Cristina second prize and in 2009 he was awarded by the Spanish Parkinson’s Disease Federation. He is the head of the Neuroscience and Motor Control Laboratory at the University of A Coruña, holds the HM-Hospitals Chair for Sports Traumatology and Neuroscience and he is the Director of the Brain Stimulation Center of Galicia, Spain.