ABSTRACT
Donald Olding Hebb's great legacy is his book, The Organisation of Behavior, first published in 1949, which would introduce the concepts of synaptic plasticity, cell assemblies and reverberatory activity to account for the neural events underlying thought and behaviour – ideas that have a profound impact on neuroscience and psychology. His ideas have not only stood the test of time but become engrained in just about every area of psychology and neuroscience. One of Hebb's most important innovations in The Organization of Behavior was to replace the simple reflex with a neural circuit that contained a large assembly of cells – an idea that had first been suggested by the Spanish neuroscientist Rafael Lorente de No in the 1930s. Hebb saw that if the assembly remained active after the sensory stimulation has ceased, then it could also provide the "structural engram" for imagery or mental representations in the brain.
