Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Donald O. Hebb


Scientific American, January 1993, p.124

The Mind and Donald O. Hebb

Peter M. Milner

Professor Emeritus of psychology, McGill University

Most of Donald Hebb’s research at McGill University was related to his cell-assembly theory. His 1949 book, The Organization of Behavior, is a keystone of modern neuroscience.

Hebb proposed that adult intelligence was crucially influenced by experience during infancy. Most experimental results supported his theory that animals raised in an enriched, or more complex, environment would, in later life, outperform animals raised in bare cages.

His work with chimpanzees influenced his conclusion that level of play provides a good index of intelligence.

His work in vision encompassed the knowledge that point-to-point projection from the retina to the cortex does not extend beyond the primary visual cortex.

He assumed that primary visual cortex neurons projected into surrounding cortex, which could recombine signals from different parts of the image.  The convergence on the same target neurons could then return to earlier neurons, closing feedback loopsRepeated activation of any given loop might then strengthen that loop.  If synapses persistently take part in firing of neurons, a growth process takes place to increase the efficiency of neuronal stimulation.  Synapses that behave according to this postulate became known as Hebb synapses.

Hebbian cell assembly has often been stated as: "Neurons that fire together wire together."



   Link to — Donald Hebb — Scientific American article