Donald Olding Hebb (July 22, 1904 – August 20, 1985) was a Canadian
psychologistA psychologist is someone who studies the human mind and behavior. Research psychologists study human perception, cognition, attention, emotion, motivation, personality, behavior and interpersonal relationships...
who was influential in the area of
neuropsychologyNeuropsychology is the basic scientific discipline that studies the structure and function of the brain related to specific psychological processes and overt behaviors. The term neuropsychology has been applied to lesion studies in humans and animals...
, where he sought to understand how the function of
neuronA neuron is an excitable cell in the nervous system that processes and transmits information by electrochemical signaling. Neurons are the core components of the brain, the vertebrate spinal cord, the invertebrate ventral nerve cord, and the peripheral nerves...
s contributed to psychological processes such as
learningLearning is acquiring new knowledge, behaviors, skills, values, preferences or understanding, and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning may...
. He has been described as the father of neuropsychology and neural networks.
Life
Donald Hebb was born in
ChesterChester is an incorporated Canadian village located in and part of Nova Scotia's Chester Municipal District in the southeastern part of Lunenburg County.-History:...
,
Nova ScotiaNova Scotia is a Canadian province located on Canada's southeastern coast. It is the most populous province in Atlantic Canada. Its capital, Halifax, is a major economic centre of the region. Nova Scotia is the second-smallest province in Canada with an area of...
, the oldest of four children of Arthur M. and M. Clara (Olding) Hebb, and lived there until the age of 16, when his parents moved to
Dartmouth, Nova ScotiaDartmouth , founded in 1750, is a community and planning area of the Halifax Regional Municipality, a provincially designated Metropolitan Area, and a former city in the Canadian province of Nova Scotia...
.
Donald's parents were both physicians. Donald's mother was heavily influenced by the ideas of
Maria MontessoriMaria Montessori was an Italian physician, educator, philosopher, humanitarian and devout Catholic; she is best known for her philosophy and the Montessori method of education of children from birth to adolescence...
, and she home schooled him until the age of 8. He performed so well in elementary school that he was promoted to the 7th grade at 10 years of age. Although his rebellious attitude and disrespect for authority may have contributed to his failing the 11th grade, he graduated from the 12th grade two years later. (At that time in Chester, the 9th, 10th and 11th grades were taught in the same classroom by the same teacher. The year Donald failed the 11th grade, most (almost all?) of the students in the three grades failed the provincial exams and hence their year. Those failing the 9th and 10th years were moved to the next grade despite their failures. There was no 12th grade in Chester for Donald to be moved to and so he repeated the 11th grade. The following year, then living in Dartmouth, he successfully completed the 12th grade at Halifax County Academy in Halifax.)
The older of Donald's younger brothers, Andrew, obtained a law degree but went on to a career in journalism and then insurance. Donald's youngest brother, Peter, became a physician like his parents. And his sister, Catherine, eventually became a prominent physiologist. But Donald, early in life, had no aspirations toward psychology or the medical field; rather, he wanted to be a writer. He entered
Dalhousie UniversityDalhousie University is a university located in Halifax, Nova Scotia, Canada. As the largest post-secondary educational institution in the Maritime Provinces it offers a wide array of programs, including a medical program and the Dalhousie Law School. The chancellor is Mr. Fred Fountain; Dr...
aiming to become a novelist. He wasn't an exceptional student (his best subjects were math and science) but he graduated with a
Bachelor of ArtsBachelor of Arts , from the Latin artium baccalaureus, is a bachelor's degree awarded for an undergraduate course or program in either the liberal arts, the sciences or both....
degree in 1925. Afterward, he became a teacher, teaching at his old school in Chester. Later, he became a farmer in
AlbertaAlberta is one of Canada's prairie provinces. It became a province on September 1, 1905.Alberta is located in western Canada, bounded by the provinces of British Columbia to the west and Saskatchewan to the east, the Northwest Territories to the north, and the U.S. state of Montana to the south....
and then traveled around, working as a laborer in
QuebecQuebec is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking identity and the only one whose sole official language is French at the provincial level....
. During his travels he encountered the works of
Sigmund FreudSigmund Freud , Sigismund Schlomo Freud , was an Austrian neurologist who founded the psychoanalytic school of psychology...
(which he regarded as "not too rigorous"),
William JamesWilliam James was a pioneering American psychologist and philosopher trained as a medical doctor. He wrote influential books on the young science of psychology, educational psychology, psychology of religious experience and mysticism, and the philosophy of pragmatism...
, and
John B. WatsonJohn Broadus Watson is an American psychologist who established the psychological school of behaviorism, after doing research on animal behavior. He also conducted the controversial "Little Albert" experiment...
which made him consider joining the field of psychology.
At the age of 23, he decided to enter the field of psychology. He asked William Dunlop Tait, the chairman of the psychology department at
McGill UniversityMcGill University is a public research university located in Montreal, Quebec, Canada. It bears the name of James McGill, a prominent Montreal merchant from Scotland, whose bequest formed the beginning of the university...
(a post Hebb would one day hold) what he'd have to do to get in and was given a reading list and told to come back in a year's time. During this year of study, he went back to teaching.
In 1928, he became a part-time graduate student at McGill University. But, at the same time, he was appointed headmaster of a troubled school in the suburbs of Montreal. He worked with two colleagues from the university, Kellogg and Clarke, to improve the situation. He took a more innovative approach to education—for example, assigning more interesting schoolwork and sending anyone misbehaving outside (making schoolwork a privilege).
In 1931, Hebb became bedridden because of
tuberculosisTuberculosis is a common and often deadly infectious disease caused by mycobacteria...
in his hip. He used the time to read
Charles Scott SherringtonSir Charles Scott Sherrington OM, GBE, PRS was an English neurophysiologist, histologist, bacteriologist, and a pathologist, Nobel laureate and president of the Royal Society in the early 1920s...
's
The Integrative Action of the Nervous System and
Ivan PavlovIvan Petrovich Pavlov was a Russian, and later Soviet, physiologist, psychologist, and physician. He was awarded the Nobel Prize in Physiology or Medicine in 1904 for research pertaining to the digestive system...
's
Conditioned Reflexes. His master's thesis, written later that year, titled
Conditioned and Unconditioned Reflexes and Inhibition, tried to show that skeletal reflexes were due to cellular learning. This he later dismissed as "nonsense, but no immediate disproof was available at the time." And yet, one of the men who later approved the thesis,
Boris BabkinBoris Petrovitch Babkin, M.D., D.Sc, LL.D was a Russian-born physiologist, who worked in Russia, England and Canada.- Career :...
, had worked with Pavlov himself. At the very least, the thesis demonstrated the start of a thought process that would later lead to the Hebb synapse. Hebb passed cum laude. Babkin arranged for Hebb to do research on conditioning with
Leonid AndreyevLeonid Nikolaievich Andreyev was a Russian playwright and short-story writer who led the Expressionist movement in the national literature...
, another former member of Pavlov's laboratory.
Between 1933 and 1934, Hebb wrote a booklet titled
Scientific Method in Psychology: A Theory of Epistemology Based on Objective Psychology. It was never published, but it contained many ideas that would become part of his later work.
By the beginning of 1934, Hebb's life was in a slump. His wife had died, following a car accident, on his twenty-ninth birthday (July 22, 1933). His work at the Montreal school was going badly. In his words, it was "defeated by the rigidity of the curriculum in Quebec's protestant schools." The focus of study at McGill was more in the direction of education and intelligence, and Hebb was now more interested in physiological psychology and was critical of the methodology of the experiments there.
He decided to leave Montreal and wrote to Robert Yerkes at Yale where he was offered a position to study for a
PhDPHD may refer to:* Parisada Hindu Dharma, an Indonesian reform organization* PHD, a track on The Crystal Method album Tweekend* PHD finger, a protein sequence* PHD Mountain Software, an outdoor clothing and equipment company...
. Babkin, however, convinced Hebb to go study with
Karl LashleyKarl Spencer Lashley , born in Davis, West Virginia, was an American psychologist and behaviorist well-remembered for his influential contributions to the study of learning and memory...
instead.
In July 1934, Hebb was accepted to study under Karl Lashley at the
University of ChicagoThe University of Chicago is a private, coeducational research university in Chicago, Illinois, USA. It was founded by oil magnate and benefactor John D...
. His thesis was titled "The problem of spatial orientation and place learning". Hebb, along with two other students, followed Lashley to Harvard University in September, 1935. Here, he had to change his thesis. At Harvard, he did his thesis research on the effects of early visual deprivation upon size and brightness perception in a rat. That is, he raised rats in the dark and some in the light and compared their brains. In 1936, he got his PhD from Harvard.
The next year he worked as a research assistant to Lashley and as a teaching assistant in introductory psychology for
Edwin G. BoringEdwin Garrigues Boring was an experimental psychologist who later became one of the first historians of psychology.-Life:...
at
Radcliffe CollegeRadcliffe College was a women's liberal arts college in Cambridge, Massachusetts, and was the coordinate college for Harvard University. It was also one of the Seven Sisters colleges. Radcliffe College conferred joint Harvard-Radcliffe diplomas beginning in 1963 and a formal merger agreement with...
. His Harvard thesis was soon published, and he finished the thesis he started at University of Chicago.
In 1937, Hebb married his second wife, Elizabeth Nichols Donovan. That same year, on a tip from his sister Catherine (herself a PhD student with Babkin at McGill University), he applied to work with
Wilder PenfieldWilder Graves Penfield, OM, CC, CMG, FRS was an American born Canadian neurosurgeon. During his life he was called "the greatest living Canadian"...
at the
Montreal Neurological InstituteThe Montreal Neurological Institute is an academic medical centre dedicated to neuroscience located in Montreal. The MNI is closely tied to McGill University as a teaching and research centre. Its clinical partner, the Montreal Neurological Hospital is one of five teaching hospitals of the McGill...
. Here he researched the effect of brain surgery and injury on human brain function. He saw that the brain of a child could regain partial or full function when a portion of it is removed but that similar damage in an adult could be far more damaging, even catastrophic. From this, he deduced the prominent role that external stimulation played in the thought processes of adults. In fact, the lack of this stimulation, he showed, caused diminished function and sometimes
hallucinationA hallucination, in the broadest sense, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid, substantial, and...
s.
He also became critical of the
Stanford-BinetThe development of the Stanford-Binet Intelligence Scales initiated the modern field of intelligence testing. The Stanford-Binet test started with the French psychologist Alfred Binet, whom the French government commissioned with developing a method of identifying intellectually deficient children...
and
WechslerThe Wechsler Adult Intelligence Scale intelligence quotient tests are the primary clinical instruments used to measure adult and adolescent intelligence. The original WAIS was published in February 1955 by David Wechsler, as a revision of the Wechsler-Bellevue Intelligence Scale...
intelligence tests for use with brain surgery patients. These tests were designed to measure overall intelligence, whereas Hebb believed tests should be designed to measure more specific effects that surgery could have had on the patient. Together with N.W. Morton, he created the Adult Comprehension Test and the Picture Anomaly Test.
Putting the Picture Anomaly Test to use, he provided the first indication that the right temporal lobe was involved in visual recognition. He also showed that removal of large parts of the frontal lobe had little effect on intelligence. In fact, in one adult patient, who had a large portion of his frontal lobes removed in order to treat his
epilepsyEpilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures...
, he noted "a striking post-operative improvement in personality and intellectual capacity." From these sorts of results, he started to believe that the frontal lobes were instrumental in learning only early in life.
In 1939, he was appointed to a teaching position at
Queen's UniversityQueen's University, generally referred to simply as Queen's, is a coeducational, non-sectarian, research intensive, public university located in Kingston, Ontario, Canada. In 2008, Queen's maintained its status as one of the top universities in Canada.The Church of Scotland established Queen's...
. In order to test his theory of the changing role of the frontal lobes with age, he designed a variable path maze for rats with
Kenneth WilliamsKenneth Charles Williams was a British comic actor, star of 26 Carry On films and radio comedies with Tony Hancock and Kenneth Horne, as well as being a witty raconteur.-Life and career:...
called the Hebb-Williams maze, a method for testing animal intelligence later used in countless studies. He used the maze to test the intelligence of rats blinded at different developmental stages, showing that "there is a lasting effect of infant experience on the problem-solving ability of the adult rat." This became one of the main principles of
developmental psychologyDevelopmental psychology, also known as human development, is the scientific study of systematic psychological changes that occur in human beings over the course of the life span. Originally concerned with infants and children, the field has expanded to include adolescence and adult development,...
, later helping those arguing the importance of the proposed
Head StartHead Start is a program of the United States Department of Health and Human Services that provides comprehensive education, health, nutrition, and parent involvement services to low-income children and their families....
programs for preschool children in economically poor neighborhoods.
In 1942, he moved to
Orange Park, FloridaOrange Park is a town and suburb of Jacksonville in Clay County, Florida, USA. The population was 9,081 at the 2000 census. According to the U.S. Census Bureau's 2004 estimates, the town had grown to 9,243....
to once again work with Karl Lashley who had replaced Yerkes as the Director of the Yerkes Laboratories of Primate Biology at the
Yerkes National Primate Research CenterThe Yerkes National Primate Research Center, located in Atlanta, Georgia at Emory University, is one of eight national primate research centers funded by the National Institutes of Health...
. Here, studying primate behavior, Hebb developed emotional tests for chimpanzees. The experiments were somewhat unsuccessful, however because chimpanzees turned out to be hard to teach. During the course of the work there, Hebb wrote
The Organization of Behavior: A Neuropsychological Theory, his ground-breaking book that set forth the theory that the only way to explain behavior was in terms of brain function.
Afterward, he returned to
McGill UniversityMcGill University is a public research university located in Montreal, Quebec, Canada. It bears the name of James McGill, a prominent Montreal merchant from Scotland, whose bequest formed the beginning of the university...
to become a professor of psychology in 1947 and was made chairman of the department in 1948. Here he once again worked with Penfield, but this time through his students, which included Mortimer Mishkin, Haldor Enger Rosvold, and
Brenda MilnerBrenda Milner, CC, GOQ, FRS has contributed extensively to the research literature on various topics in the field of clinical neuropsychology....
, all of whom extended his earlier work with Penfield on the human brain.
His wife Elizabeth died in 1962. In 1966, Hebb married his third wife, Margaret Doreen Wright (née Williamson), a widow.
Hebb remained at McGill until retirement in 1972. He remained at McGill after retirement for a few years, in the Department of Psychology as an emeritus professor, conducting a seminar course required of all department graduate students. Afterward, in 1980, he returned to Dalhousie University as
professor emeritusA Professor Emeritus is a full professor who retires in good standing. While technically this is the term for a male and women are known as Professor Emerita, women such as Germaine Greer are known by the masculine title. This title is also given to retired professors who continue to teach and to...
of psychology.
Hebb was a member of the
American Psychological AssociationThe American Psychological Association is a professional organization representing psychologists in the U.S., with around 150,000 members and an annual budget of around $70m...
(APA) and was its president in 1960. He won the APA Distinguished Scientific Contribution Award in 1961.
Donald Hebb died in 1985, two years after his wife, in Nova Scotia. He was survived by two daughters (both by his second marriage), Mary Ellen Hebb and Jane Hebb Paul.
The Donald O. Hebb Award, named in his honor, is awarded to distinguished Canadian scientists.
The Organization of Behavior (1949)
"The Organization of Behavior" is considered Hebb's most important book. A combination of his years of work in brain surgery mixed with his study of human behavior, it finally brought together the two realms of human perception that for a long time could not be connected properly. That is, it connected the biological function of the brain as an organ together with the higher function of the mind.
There were many theories on how the brain and the mind were connected. Pavlovian theories, for example, were based on a theory of stimulus and response, based on the belief that a path existed from sensory organs to the mind, which then made a response. The problem with the theory was that it was assumed that signals travel one way to the brain. It could not explain all the extra processing that adds to the input signals of human senses. Perhaps this was based on the fact that neurons themselves transmit in only one direction, but connections between various neurons are not necessarily one-way.
In 1929,
Hans BergerHans Berger was born in Neuses near Coburg, Thuringia, Germany. He is known as the first to record electroencephalograms from human subjects and is the discoverer of the rhythmic Alpha brain waves.- Background :...
discovered that the mind exhibits continuous electrical activity and cast doubt on the Pavlovian model of perception and response because, now, there appeared to be something going on in the brain even without much stimulus.
At the same time, there were many mysteries. For example, if there was a method for the brain to recognize a circle, how does it recognize circles of various sizes or imperfect roundness? To accommodate every single possible circle that could exist, the brain would need a far greater capacity than it has.
Another theory, the
Gestalt theoryGestalt psychology or gestaltism of the Berlin School is a theory of mind and brain positing that the operational principle of the brain is holistic, parallel, and analog, with self-organizing tendencies, or that the whole is different from the sum of its parts...
, stated that signals to the brain established a sort of field. The form of this field depended only on the pattern of the inputs, but it still could not explain how this field was understood by the mind.
The behaviorist theories at the time did well at explaining how the processing of patterns happened. However, they could not account for how these patterns made it into the mind.
Hebb combined up-to-date data about behavior and the mind into a single theory. And, while the understanding of the anatomy of the brain did not advance much since the development of the older theories on the operation of the brain, he was still able to piece together a theory that got a lot of the important functions of the brain right.
His theory became known as
Hebbian theoryHebbian theory describes a basic mechanism for synaptic plasticity wherein an increase in synaptic efficacy arises from the presynaptic cell's repeated and persistent stimulation of the postsynaptic cell...
and the models which follow this theory are said to exhibit Hebbian learning. This method of learning is best expressed by this quote from the book:
- When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased
This is often paraphrased as "Neurons that fire together wire together." It is commonly referred to as Hebb's Law.
The combination of neurons which could be grouped together as one processing unit, Hebb referred to as "cell-assemblies". And their combination of connections made up the ever-changing algorithm which dictated the brain's response to stimuli.
Not only did Hebb's model for the working of the mind influence how psychologists understood the processing of stimuli within the mind but also it opened up the way for the creation of computational machines that mimicked the biological processes of a living nervous system. And while the dominant form of synaptic transmission in the nervous system was later found to be chemical, modern
artificial neural networkAn artificial neural network , usually called "neural network" , is a mathematical model or computational model that tries to simulate the structure and/or functional aspects of biological neural networks. It consists of an interconnected group of artificial neurons and processes information using...
s are still based on the transmission of signals via electrical impulses that Hebbian theory was first designed around.
Hebb as an educator
Throughout his life Hebb enjoyed teaching and was very successful as a teacher. Both in his early years as a teacher and a headmaster in a Montreal school and in his later years at McGill University, he proved to be a very effective educator and a great influence on the scientific minds which were then his students.
As a professor at McGill, he believed that one could not teach motivation, but rather create the conditions necessary for students under which to do their study and research. One could train them to write, help them choose a problem to study, and even help keep them from being distracted, but the motivation and passion for research and study had to come from the students themselves. He believed that students should be evaluated on their ability to think and create rather than their ability to memorize and reprocess older ideas.
Hebb believed in a very objective study of the human mind, more as a study of a biological science. This attitude toward psychology and the way it is taught made McGill University a prominent center of psychological study.
Hebb also came up with the
A/S ratioThe A/S ratio is the proportion of the brain not directly connected with either receptor inputs or motor outputs, where A is the association cortex and S is the sensory cortex. The A/S ratio can be measured for any organism with a brain, and the higher the A/S ratio, the more complex the brain...
, a value that measures the brain complexity of an organism.
Sensory deprivation, military research, and torture
Hebb's name has often been invoked in discussions of the involvement of psychological researchers in interrogation techniques, including the use of sensory deprivation, because of his research into this field. Speaking at a Harvard symposium on sensory deprivation in June, 1958, Dr. Hebb is quoted as remarking:
The work that we have done at McGill University began, actually, with the problem of brainwashing. We were not permitted to say so in the first publishing.... The chief impetus, of course, was the dismay at the kind of “confessions” being produced at the Russian Communist trials. “Brainwashing” was a term that came a little later, applied to Chinese procedures. We did not know what the Russian procedures were, but it seemed that they were producing some peculiar changes of attitude. How?
One possible factor was perceptual isolation and we concentrated on that.
Recent research has argued that Dr. Hebb's sensory deprivation research was funded by and coordinated with the CIA (McCoy, 2007). Some of this research was done in secret, and the results were initially shared only with U.S. authorities. Some of this research involved human subjects that were put through hours of sensory deprivation treatments that by today's standards would be considered torture.
Known Students
- M. Philip Bryden
- Donald Forgays
- Stevan Harnad
thumb|right|Professor Stevan HarnadProfessor Stevan Harnad is a cognitive scientist.He was born in Budapest, Hungary. He did his undergraduate work at McGill University and his graduate work at Princeton University's Department of Psychology...
- Woodburn Heron
- Bernard Hymovitch
- W. Jake Jacobs
- Doreen Kimura
Doreen Kimura is a professor at Simon Fraser University. She holds a PhD in psychobiology. Among other interests, her interests include the relationship between sex and cognition and promoting academic freedom; she is the founding president of the .While some criticized Lawrence Summers' claims...
- Helen Mahut
- Ronald Melzack
Ronald Melzack, OC, OQ, FRSC is a Canadian psychologist.After studying for his Ph.D. in 1954 with D. O. Hebb at McGill University in Montreal, he began to work with patients who suffered from "phantom limb" pain — people who feel pain in an arm or leg that has been removed...
- Brenda Milner
Brenda Milner, CC, GOQ, FRS has contributed extensively to the research literature on various topics in the field of clinical neuropsychology....
- Peter Milner
- Mortimer Mishkin
- Gordon Mogenson
- Aryeh Routtenberg
- Seth Sharpless
- Case Vanderwolf