There are three psychologists who, in my opinion, are most responsible for the development of cognitive psychology as a movement as well as for its incredible popularity today. They are Donald Hebb, George Miller, and Ulric Neisser. There are no doubt others we could add, but I am sure no one would leave these three out!

Donald Olding Hebb was born in 1904 in Chester, Nova Scotia. He graduated from Dalhousie University in 1925, and tried to begin a career as a novelist. He wound up as a school principle in Quebec.

He began as a part-time graduate student at McGill University in Montreal. Here, he began quickly disillusioned with behaviorism and turned to the work of Wolfgang Kohler and Karl Lashley. Working with Lashley on perception in rats, he received his PhD from Harvard in 1936.

He took on a fellowship with Wilder Penfield at the Montreal Neurological Institute, where his research noted that large lesions in the brain often have little effect on a person’s perception, thinking, or behavior.

Moving on to Queens University, he researched intelligence testing of animals and humans. He noted that the environment played a far more significant role in intelligence than generally assumed.

In 1942, he worked with Lashley again, this time at the Yerkes Lab of Primate Biology. He then returned to McGill as a professor of psychology, and became the department chairperson in 1948.

The following year, he published his most famous book, The Organization of Behavior:  A Neuropsychological Theory.  This was very well received and made McGill a center for neuropsychology.

The basics of his theory can be summarized by defining three of his terms:  First, there is the Hebb synapse.  Repeated firing of a neuron causes growth or metabolic changes at the synapse that increase the efficiency of that synapse in the future.  This is often called consolidation theory, and is the most accepted explanation for neural learning today.

Second, there is the Hebb cell assembly.  There are groups of neurons so interconnected that, once activity begins, it persists well after the original stimulus is gone.  Today, people call these neural nets.

And third, there is the phase sequence.  Thinking is what happens when complex sequences of these cell assemblies are activated.

He humbly suggested that his theory is just a new version of connectionism -- a neo- or neuro-connectionism.  This connectionism is today the basic idea behind most models of neurological functioning.  It should be noted that he was president of both the APA and its Canadian cousin, the CPA.  Donald Hebb died in 1985.