The impact of Donald O. Hebb on neuroscientific research

Donald Olding Hebb was born on the 22nd July 1904. He was the first born in a family that had four children. His father was called Arthur Hebb and the mother was Clara Hebb. Their family lived in Chester, Nova in Canada. He was a good performer during his elementary school period though he used to portray rebellious attitude. Donald had an ambition of becoming a novel writer. He joined Dalhousie with the sole aim of becoming a novelist. He was not an academically outstanding student at the university but performed above average in math and science. He graduated in 1925 with a degree in Arts. He chose to begin a career in teaching as he deemed it as being more practical. He was able to rise to the post of a principle in the field of education but he chose to quit. He ventured into farming in Alberta but was later to work as a laborer in Quebec. This required him to travel a lot and in the process he was able to access the works done by John Watson, William James and Sigmund Freud, all of whom he had greatly fancied. This made him contemplate joining the field of psychology (Sheehy, 2002).

Joining the field of psychology
After his 23rd birthday, Hebb plunged into the field of psychology. The desire was burning and irresistible. He approached William Tait who was at the helm of the department of psychology at Mc Gill University at that time. He was given a list of books to read for one year, a period which he resumed teaching. In 1928, he had joined the graduate school at the university though he did it on a part time basis. He had been appointed as the head teacher of a school in Montreal that had been marred by indiscipline. The interesting part is the manner in which he chose to counter the situation. He made schoolwork more interesting by administering interesting assignments and rude students would be sent out, to make the schoolwork more of a privilege. Hebb was sick and in the course of this period, he managed to read Conditioned Reflexes, a book that had been written by Ivan Pavlov. He was also able to read The Integrative Action of the Nervous System, which had been authored by Charles Sherrington. Later in the course of that year, he wrote his thesis for masters studies. It was named Conditioned and Unconditioned Reflexes and Inhibition. He was trying to demonstrate that cellular learning is what caused skeletal reflexes. While Hebb was not content with his thesis, it was approved by Boris Babkin, who had assisted Ivan Pavlov in his work. The thesis was able to demonstrate how the process of thought started. Boris made an arrangement for Hebb to further his research, specifically on conditioning, this time with Leonid Andreyev who had initially worked in Pavlovs laboratory (Haider, 2008).

By 1934, Hebb had written a book, Scientific Method in Psychology A Theory of Epistemology Based on Objective Psychology. This book was very rich in information but it was never able to reach the stage of publishing. It was to later provide a basis for the works of Hebb. He was not comfortable in Montreal and requested Robert Yerkes for a PhD. Position at Yale, but this was not to be as Boris was quick to convince him to join Karl Lashley in his studies at Chicago University. The title of his thesis was The problem of spatial orientation and place learning. He had to transfer to Harvard University when Karl Lashley did. This forced him to change his thesis to The effects of early visual deprivation upon size and brightness perception in a rat. This entailed rearing rats in conditions of light and darkness and then comparing their brains. He was awarded a PhD. by Harvard University in 1936. He continued to assist Lashley in research and as a teaching assistant at Radcliff College. He was later able to complete the research he had started at Chicago University (Sejnowski, 2003).

He made an application to join Montreal Neurological Institute and join Wilder Penfield in Research. He was biased towards establishing how brain surgery and injuries could affect the manner in which the brain functioned. He was able to conclude that while a childs brain was able to fully recover if a portion of it was removed the case was worse and almost irreversible as far as adult brain damage is the subject. His deduction was that external stimulation played a very pivotal role in the thinking process of an adult. He criticized Wechsler test together with Stanford - Binet test which were in application for determining the intelligence of patients who had undergone brain surgery. He felt that these test were focused on the overall intelligence of the patient while they were supposed to measure the effects that had been brought about by surgery. He teamed up with W. Morton to create Adult Comprehension Test and Picture Anomaly Test (Milner, 2006).

He got a teaching appointment to Queens University in 1939. He joined Kenneth Williams to come up with the Hebb-William maze, a device which was to be used on many occasions to determine animal intelligence. He was able to use this on rats and deduced that an aspect of childhood experience was important in the ability of an adult to solve problems. He went to Orange Park in Florida in 1942 at Yerkes National Primate Research Center. He advanced his studies on primates and was able to come up with a test that could determine the emotional status of chimpanzees. In 1947, he became a professor of psychology at Mc Gill University and the departmental chairman. He remained at the institution upto the period of his retirement (Leahey, 2000).

Conclusion
Hebb was able to come up with different intelligence tests which enabled neuroscientific research to be carried out easily and more specifically than had been the case previously. His tests could be carried out on human and animals. His studies led him to the conclusion that experience played a pivotal role on the intelligence of a person or animal. He postulated that behavior was determined by a combination of hereditary as well as the environmental components. He felt that behavior was difficult to understand because it was not easy to determine all the activities of our nervous system. Most notable conclusions of his work were summarized in the three postulates of his theory. These postulates included Hebbian learning-which is concerned with the neuron connection and synaptic activities, cell assemblies-which talks about groupings of neurons which act together, and the phase sequence-which demonstrates the sequence of thinking.

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