[1] He joined the University of Alberta, Canada, in 1975 when he took the Killam Memorial Chair as Professor of Physics, a position which he held until his retirement in 1992.
This model was subsequently expanded by Stuart, Takahashi and Umezawa with their proposal of the development of long range correlations among neurons due to the interaction of two quantum fields.
The approach was built upon by many others, including Karl H. Pribram, and was later expanded by Giuseppe Vitiello to a dissipative quantum model of brain.
[3][4][5] Umezawa's scientific work has been characterized by his colleagues at UWM as "marked by extreme originality".
[1] After his death in 1995, Umezawa's family, friends and students set up the Umezawa Fund at the University of Alberta in his memory, dedicated to support studies in physics; among the Memorial Distinguished Visitors has been physicist Gordon Baym of the University of Illinois in 2007.