Profile

Satoru Iwata　

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

Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan
Tel: +81 3 5841 7430 (ext. 27430) 

E-mail：iwata＠mist.i.u-tokyo.ac.jp

[ Personal Site ]

Biography

Research Topics

Solving Fundamental Problems in Mathematical Engineering
– Discrete Optimization: Design and Analysis of Efficient Algorithms on Matroids and Submodular Functions
– Discrete Mathematical Engineering: Engineering Applications of Discrete Optimization Methods (Systems Analysis and Chemoinformatics)

Selected Publications

S. Iwata and M. Takamatsu: Index minimization of differential-algebraic equations in hybrid analysis for circuit simulation, Mathematical Programming, 103 (2010), 105-121.

J. F. Geelen, S. Iwata, and K. Murota: The linear delta-matroid parity problem, Journal of Combinatorial Theory, B88 (2003), 377-398.

S. Iwata, L. Fleischer, and S. Fujishige: A combinatorial strongly polynomial algorithm for minimizing submodular functions, Journal of the ACM, 48 (2001), 761-777.

Profile

Andrea Benucci

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: +81-48-467-5203
Fax:

E-mail：andrea.benucci@riken.jp

[Home Page]

略歴

Research Themes

Computations in biological neural networks, in particular linear and non-linear analyses of large-scale neuronal recordings.

My research aims at linking neural architectures to the underlying computations. To do so, I integrate experimental methods for all-optical dissection of neuronal circuits with large-scale dynamical network models based on artificial neural networks (aNNs). The connectivity architecture of aNNs closely mirrors that of biological neural networks, thus representing an effective theoretical framework to unify computational, algorithmic, and implementation levels of analysis.

Selected Publications

Aoki, R., Tsubota, T., Goya, Y., Benucci, A., An automated platform for high-throughput mouse behavior and physiology with voluntary head-fixation. Nature Comms., 8:1196, (2017)

Benucci, A., Saleem, A.B., Carandini, M. Adaptation maintains population homeostasis in primary visual cortex. Nature Neurosci., Jun; 16(6):724-9, (2013)

Pearson R.A., Barber A.C., Rizzi M., Xue T., West E.L., Duran Y., Smith A.J., Chuang J.Z., Azam S.A., Luhmann U.F.O., Benucci A., Sung C.H., Carandini M., Yau K.W., Sowden J.C., Ali R.R. Restoration of vision after transplantation of photoreceptors. Nature, 485(7396):99-103, (2012)

Benucci, A., Ringach, D.L., Carandini, M. Coding of stimulus sequences by population responses in visual cortex. Nature Neurosci., 12(10):1317-24, (2009)

Profile

Taro Toyoizumi（豊泉 太郎）

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

[Home Page]

Curriculum Vitae

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