CBS – Toyoizumi

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Taro Toyoizumi(豊泉 太郎)
toyoizumi

Adjunct Professor,
Department of Mathematical Informatics, Graduate School of Information
Science and Technology, University of Tokyo

RIKEN Center for Brain Science, Team Leader

2-1 Hirosawa, Wako-shi, Saitama 351-0198
Tel: +81-48-467-9644
Fax: +81-48-467-9670

E-mail:taro.toyoizumi@riken.jp

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Curriculum Vitae

Mar. 2001 Graduated from the Department of Physics, School of Science,
Tokyo Institute of Technology
Mar. 2003 Graduated from the Master Course of the Department of
Complexity Science and Engineering, Graduate School of Frontier
Sciences, The University of Tokyo
Mar. 2006 Graduated from the Doctor Course of the Department of
Complexity Science and Engineering, Graduate School of Frontier
Sciences, The University of Tokyo
Apr. 2006 – Feb. 2008 Japan Society for the Promotion of Science
Postdoctoral Fellow (RIKEN Brain Science Institute, Center for
Theoretical Neuroscience, Columbia University)
Mar. 2008 – Feb. 2010 The Robert Leet and Clara Guthrie Patterson
Trust Postdoctoral Fellow (Center for Theoretical Neuroscience,
Columbia University)
Apr. 2010 – Mar. 2011 Special Postdoctoral Researcher, RIKEN Brain
Science Institute
Apr. 2011 – Mar. 2018 Team Leader, RIKEN Brain Science Institute
Apr. 2018 Team Leader, RIKEN Center for Brain Science
Apr. 2019 Adjunct Professor, Department of Mathematical Informatics,
Graduate School of Information Science and Technology, University of
Tokyo

Research Themes

Computational Neuroscience, Theory of Neural Adaptation using
Statistical Physics and Information Theory Tools

Our research is in the field of Computational Neuroscience. Computer
models are used to study how information is processed in the brain and
how the brain circuits adapt to and learn from the environment. We
employ analytical techniques from statistical physics and information
theory to investigate key functional properties for neuronal circuits.
We use these techniques to reduce diverse experimental findings into a
few core concepts that robustly explain the phenomena of interest.
We are particularly interested in activity-dependent forms of
plasticity in the brain, which are known to have large impacts on
learning, memory, and development. With the aid of mathematical
models, we seek a theory that unites the cellular level plasticity
rules and the circuit level adaptation in different brain areas and
animal species. Efficacy of neurons to represent and retain
information is estimated from the structure and behavior of resulting
circuits.

Selected Publications

Isomura T and Toyoizumi T.: “Error-Gated Hebbian Rule: A Local
Learning Rule for Principal and Independent Component Analysis”
Scientific Reports , 8, 1835 (2018), doi:10.1038/s41598-018-20082-0


Buckley C L and Toyoizumi T.: “A theory of how active behavior
stabilizes neural activity: neural gain modulation by closed-loop
environmental feedback”
PLOS Computational Biology , 14, e1005926 (2018), doi:
10.1371/journal.pcbi.1005926


Kuśmierz Ł and Toyoizumi T.: “Emergence of Lévy walks from
second-order stochastic optimization”
Physical Review Letters, 119, 250601 (2017), doi: 10.1103/PhysRevLett.119.250601


Tajima S, Mita T, Bakkum D, Takahashi H, and and Toyoizumi T.:
“Locally embedded presages of global network bursts”
Proc. Natl. Acad. Sci, 114, 9517-9522 (2017), doi: 10.1073/pnas.1705981114


Huang H and Toyoizumi T.: “Clustering of neural code words revealed by
a first-order phase transition”
Physical Review E, 93, 062416 (2016), doi: 10.1103/PhysRevE.93.062416


Shimazaki H, Sadeghi K, Ishikawa T, Ikegaya Y, and Toyoizumi T.:
“Simultaneous silence organizes structured higher-order interactions
in neural populations.”
Sci Rep, 5, 9821 (2015), doi: 10.1038/srep09821


Toyoizumi T, Kaneko M, Stryker MP, and Miller KD.: “Modeling the
dynamic interaction of Hebbian and homeostatic plasticity”
Neuron, 84(2), 497-510 (2014), doi: 10.1016/j.neuron.2014.09.036


Toyoizumi T, Miyamoto H, Yazaki-Sugiyama Y, Atapour N, Hensch TK, and
Miller KD.: “A theory of the transition to critical period plasticity:
inhibition selectively suppresses spontaneous activity” Neuron, 80(1),
51-63 (2013), doi: 10.1016/j.neuron.2013.07.022


Toyoizumi T and Abbott LF.: “Beyond the edge of chaos: Amplification
and temporal integration by recurrent networks in the chaotic regime”
Physical Review, E 84(5), 051908 (2011), doi: 10.1103/PhysRevE.84.051908


Toyoizumi T, Aihara K, and Amari S.: “Fisher information for
spike-based population decoding.”
Phys Rev Lett, 97(9), 98102 (2006), doi: 10.1103/PhysRevLett.97.098102


Toyoizumi T, Pfister JP, Aihara K, and Gerstner W.: “Generalized
Bienenstock-Cooper-Munro rule for spiking neurons that maximizes
information transmission.”
Proc Natl Acad Sci U S A, 102(14), 5239-44 (2005), doi: 10.1073/pnas.0500495102


 

Professor Kantaro Fujiwara

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Kantaro Fujiwara
Kantaro Fujiwara
Project Associate Professor
International Research Center for Neurointelligence, The University of Tokyo
Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo

 

7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Tel: +81-3-5841-8247 (Ext. 28247)
Fax:

 

E-mail:fujiwara@mist.i.u-tokyo.ac.jp

 

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C.V.

March 2008 Graduated from the Doctor Course of the Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo
April 2008 Postdoctoral Fellow of Japan Society for the Promotion of Science (Institute of Industrial Science, The University of Tokyo)
April 2011 Assistant Professor at the Division of Mathematics, Electronics and Informatics, Graduate School of Science and Engineering, Saitama University
April 2014 Assistant Professor at the Department of Management Science, Faculty of Engineering, Tokyo University of Science
April 2018 Project Associate Professor at the International Research Center for Neurointelligence, The University of Tokyo

Research Themes

The main topics are computational neuroscience and data analysis of neural systems.
1. Computational Neuroscience
Mathematical modeling of neural networks. Modeling various neuronal phenomena such as learning and adaptation.
2. Data Analysis of Neural Systems
Establishing mathematical theories and novel analysis method of neuronal data.
3. Biological Information Processing
Mathematical modeling of pancreatic beta cell and diabetes.

Selected Publications

– R. Nomura , Y-Z Liang, K. Morita, K. Fujiwara and T. Ikeguchi,
Threshold-varying integrate-and-fire model reproduces distributions of spontaneous blink intervals,
PLOS ONE 13, 10, e0206528 (2018)
– T. Kobayashi, Y. Shimada, K. Fujiwara and T. Ikeguchi,
Reproducing Infra-Slow Oscillations with Dopaminergic Modulation,
Scientific Reports, 7, 2411 (2017)
– H. Ando and K. Fujiwara,
Numerical analysis of bursting activity in an isolated pancreatic β-cell model,
Nonlinear Theory and its Applications, 7, pp. 217-225 (2016)
– K. Fujiwara, H. Suzuki, T. Ikeguchi and K. Aihara,
Method for analyzing time-varying statistics on point process data with multiple trials,
Nonlinear Theory and its Applications, 6, pp. 38-46 (2015)

seisanken – omi

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Takahiro Omi(近江 崇宏)
近江 崇宏

Associate Professor
Institute of Industrial Science, The University of Tokyo
Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo

Aihara lab., Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Tel: +81-3-5452-6697 (Ext. 56697)
Fax:

E-mail:omi@sat.t.u-tokyo.ac.jp

Curriculum Vitae

March 2007 Bachelor of Science from Faculty of Science, Kyoto University
March 2009 Master of Science from Department of Physics, Graduate School of Science, Kyoto University
March 2012 Ph.D. in Science from Department of Physics, Graduate School of Science, Kyoto University
April 2012 Researcher, Japan Science and Technology
April 2013 Japan Society for the Promotion of Science Fellowship for Young Scientists
April 2016 Project Research Associate, Institute of Industrial Science, The University of Tokyo
April 2018 Project Associate Professor, Institute of Industrial Science, The University of Tokyo

Research Themes

Our main topics is time-series analysis. We especially focus on the statistical analysis of point process data, which describe events that occur irregularly in time. Our research includes

(1) the development of estimation and forecast method based on Bayesian statistics and

(2) its application to earthquake, economic, and social data.

Selected Publications

T. Omi, Y. Hirata, and K. Aihara,

“Hawkes process model with a time-dependent background rate and its application to high-frequency financial data”,

Physical Review E 96, 012303 (2017).


T. Omi, Y. Ogata, Y. Hirata, and K. Aihara,

“Forecasting large aftershocks within one day after the main shock”,

Scientific Reports 3, 2218 (2013).


T. Omi and S. Shinomoto,

“Optimizing time histograms for non-Poissonian spike trains”,

Neural Computation 23, 3125 (2011).