[Seminar] "A dynamical principle of functional differentiation in the brain: a mathematical point of view" by Professor Ichiro Tsuda

Speacker: Professor

Affiliation: Chubu University Academy of Emerging Sciences

Title: A dynamical principle of functional differentiation in the brain: a mathematical point of view

Abstract:

One of the most striking characteristics of the developing brain is the generation of functionally differentiated neural areas, while emerging interactions develop between networking areas, whereby the brain works as a whole. Functional differentiation is well known as, typically, Brodmann areas or as a functional map in that different areas represent different cognitive and behavioral functions. Recently, the functional parcellation of the human neocortex was observed by means of the functional connectivity of the dynamics involved in the corresponding neural networks, and was shown to consist of finer areas compared with the functional map. The presence of functional parcellation suggests that a self-organization of neural networks occurs rapidly, based on chaotic dynamics, under various constraints of behaviors. A similar self-organization of neural networks may also occur during the ontogenetic development of the brain under constraints, which may be stimulation by light and sound from the external environment or the physical pressure stemming from the individual’s own skull. In this respect, we hypothesize the existence of a common principle of self-organization with constraints in both functional differentiation and functional parcellation.

To clarify the neural mechanism of functional differentiation, we constructed a mathematical model of self-organization with constraints. By casting different constraints, we investigated the mathematical structures embedded into the process of functional differentiation at various stages of neuronal development and obtained the following dynamic behaviors. We observed the genesis of a neuron-like dynamical system in the developmental process of coupled dynamical systems. We found the genesis of neuron-like units that respond specifically to sensory stimuli. We also detected the genesis of functional modules from randomly uniform networks of oscillations, where one module can be interpreted as a “higher” level (such as a cognitive area) and the other can be interpreted as a “lower” level (such as a motor area interacting with the body). In all cases, the appearance of chaos and chaotic itinerancy in the whole network plays an essential role in the generation of functional elements.

Biography:

1953, born in Okayama prefecture in Japan.

1982, graduate from Kyoto University, Graduate School of Science,

Department of Physics. (Dsc degree in Physics from Kyoto University)

1988, Associate professor of Kyushu Institute of Technology,

Faculty of Computer Science, Department of Artificial Intelligence.

1993, Professor of Hokkaido University, Faculty of Science,

Department of Mathematics.

2005, Professor of Research Institute for Electronic Science , Hokkaido University.

2015, Professor of Department of mathematics, Graduate School of Science, Hokkaido University

2017, Professor of Chubu University Academy of Emerging Sciences, Chubu University

Administration:

2008‒2015, Director of Research Center for Integrative Mathematics, Hokkaido University.

2012‒2013, Deputy Director of Research Institute for Electronic Science, Hokkaido University.

Main social activity:

2014, Associate Member of Science Council of Japan

2016, Steering Committee of MEXT Joint Usage/Research Center “Center for Mathematical Modeling and Applications”, Meiji Institute for Advanced Study of Mathematical Sciences

Main Award:

・Plenary Lecture in the 1st SIAM Pacific Rim Conference on the Dynamical Systems, 2000.

・Plenary Lecture in the 6th International Congress on Industrial and Applied Mathematics (ICIAM), 2007.

・2010 HFSP　Program Award, “ Deliberative Decision Making in Rats”.

・ICCN2013 Merit Award, “Pioneering and Outstanding Contribution to the Field of Cognitive Neurodynamics, Its Journal and Series of Conference”.