Shun'ichi Amari

Shun'ichi Amari (甘利 俊一, Amari Shun'ichi), is a Japanese engineer and neuroscientist born in 1936 in Tokyo, Japan. He was a pioneer in information geometry and artificial intelligence.

Shun'ichi Amari
甘利 俊一
Shun'ichi Amari
Born	1936 (age 88–89) Tokyo, Japan
Alma mater	University of Tokyo
Known for	Information geometry Amari distance Artificial intelligence
Awards	IEEE Emanuel R. Piore Award (1997)
Scientific career
Fields	Neuroscience
Institutions	RIKEN

Education

He majored in Mathematical Engineering in 1958 from the University of Tokyo then graduated in 1963 from the Graduate School of the University of Tokyo.

His Master of Engineering in 1960 was entitled Topological and Information-Theoretical Foundation of Diakoptics and Codiakoptics. His Doctor of Engineering in 1963 was entitled Diakoptics of Information Spaces.

Career

Shun'ichi Amari received several awards and is a visiting professor of various universities.

He is the author of more than 200 peer-reviewed articles.^[1] He is known for developing information geometry. He also independently invented the Hopfield network in 1972,^[2] a form of self-organized recurrent neural network.

Artificial intelligence

Amari made significant advances in artificial intelligence. In 1967, he proposed the first deep learning artificial neural network (ANN) using the stochastic gradient descent (SGD) algorithm. The same year, Amari and his student H. Saito reported the first multilayer perceptron (MLP) neural network trained by SGD.^[3] The concept of backpropagation was also anticipated by Amari in the 1960s.^[4]

In 1972, Amari and Kaoru Nakano published the first papers on deep learning recurrent neural networks (RNN). The same year, Amari invented the Amari–Hopfield network. The Amari network, the earliest deep learning recurrent neural network (RNN), was first published by Amari in 1972. It was rediscovered by John Hopfield in 1982 as the Hopfield network.^[3]

Later career

He is currently holding a position of the RIKEN lab and is vice-president of Brain Science Institute, director of Brain Style Information Systems Group and team leader of Mathematical Neuroscience Laboratory.^[5]

He was a winner of the IEEE Emanuel R. Piore Award (1997).^[6]

Key works

• A Geometrical Theory of Information (in Japanese), Kyoritsu, 1968
• Information Theory (in Japanese), Daiamondo-sha, 1971
• Mathematical Theory of Nerve Nets (in Japanese), Sangyotosho, 1978
• Methods of Information Geometry,^[7] in collaboration with Hiroshi Nagaoka, originally published in Japanese in 1993 and published in English in 2000 with the American Mathematical Society (AMS).

Awards and honors

• Japan Academy Prize (1995)
• IEEE Emanuel R. Piore Award (1997)
• C&C Prize (2003)
• Person of Cultural Merit (2012)
• Order of Culture (2019)
• Kyoto Prize (2025)^[8]