Rafael Lorente de Nó (1902-1990), Cajal's youngest pupil and the closed circuits American psychology built on

Cajal's youngest direct disciple, in Madrid at eighteen, in the United States from 1931 and at the Rockefeller Institute from 1936 to 1970. He named the cortical elementary unit in 1933, two decades before electrodes could test it, and described self-reexciting closed chains of neurons that gave Donald Hebb the mechanism for the cell assembly. He was nominated for the Nobel four times and never won, and he refused to the end to accept the ionic theory of the nerve impulse.