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INM-6 Seminar: Talk by Prof. Tetsuya Yagi

Graduate School of Engineering, Osaka University

18 Sep 2018 11:00
18 Sep 2018
Bldg. 15.9v, E1, Room 4001b

Reproducing dynamical properties of retinal responses in real time with a neuromorphic retina model

In the vertebrate retina, images are continuously transduced into graded voltage responses in the photoreceptor array and processed with electrochemical properties of the neuronal circuits. The ganglion cells, out neurons of the retina, transform images represented with the graded voltage responses into action potentials and send them to the brain in parallel. In order to understand how images are encoded with the spatio-temporal distribution neuronal voltage responses, physiological recordings have been made from isolated retinas, or retinas in anesthetized animals while using simplified or unrealistic optical stimulations, e.g. spot of light, randomly modulated checker patterns and so on. The images received by the retina under natural visual environment, however, are quite different from these stimulations and, more importantly, are continuously influenced by eye movements. Envisaging such technical restrictions of physiological experiments, we have developed a neuromorphic retina model that mimics fundamental circuit structure of the retina and reproduces neuronal responses to images in real time. The model consists of a neuromorphic silicon retina and FPGA module and can be installed on an eye movement apparatus. In my talk, I will demonstrate “virtual in vivo experiments” using the neuromorphic retina model to study the functions of retinal neurons in natural visual environment. I also refer to possible applications of the model to robot vision and visual prostheses.

Dr. Junji Ito