Textbook of AI

1904–1985, Psychologist, neuroscientist

Also known as: D. O. Hebb, Donald Olding Hebb

Donald Olding Hebb was a Canadian psychologist whose 1949 book The Organization of Behavior: A Neuropsychological Theory proposed the first plausible mechanism by which learning could be implemented in biological neural tissue. The proposal, now called the Hebbian rule, is captured in the slogan "cells that fire together, wire together": when a neuron repeatedly takes part in firing another, the synaptic connection between them strengthens. Hebb also introduced the idea of cell assemblies: groups of neurons that, through Hebbian strengthening, come to fire as a coherent group and so represent perceptual or cognitive units.

Hebbian learning is the conceptual ancestor of every unsupervised and self-organising learning rule in artificial neural networks, from the perceptron's update rule (a supervised refinement of Hebb), through the Kohonen self-organising map and the Hopfield network's storage rule, to long-term potentiation in modern computational neuroscience. The principle was experimentally vindicated decades later when Bliss and Lømo demonstrated long-term potentiation in the hippocampus in 1973.

Hebb spent most of his career at McGill University in Montréal, where he chaired the Department of Psychology from 1948 and shaped a generation of cognitive psychologists. He resisted the radical behaviourism dominant in his era and insisted that internal mental representations were a proper subject of scientific psychology, a stance that helped catalyse the cognitive revolution of the 1950s and 1960s.