Mark Richard Rosenzweig (September 12, 1922 – July 20, 2009) was an American research psychologist whose research on

neuroplasticity Neuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of neural networks in the brain to change through growth and reorganization. It is when the brain is rewired to function in some way that differs from how it p ...

in animals indicated that the adult

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

remains capable of anatomical remodelling and reorganization based on life experiences, overturning the

conventional wisdom The conventional wisdom or received opinion is the body of ideas or explanations generally accepted by the public and/or by experts in a field. In religion, this is known as orthodoxy. Etymology The term is often credited to the economist John ...

that the brain reached full maturity in childhood.

Early life and education

Rosenzweig was born on September 12, 1922, in

Rochester, New York Rochester () is a City (New York), city in the U.S. state of New York (state), New York, the county seat, seat of Monroe County, New York, Monroe County, and the fourth-most populous in the state after New York City, Buffalo, New York, Buffalo, ...

, to Jews of Eastern European origin, in which his bilingual parents (his lawyer father and homemaker mother spoke both

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

and

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

) helped foster an interest in language and learning.Anwar, Yasmin
"Mark Rosenzweig, pioneer in brain plasticity, learning and hearing, has died at 86 "
''UCBerkeley News'', August 3, 2009. Accessed August 12, 2009. He attended the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of ...

there planning to major in history, but ended up switching to psychology and receiving a bachelor's degree in 1943 and a master's degrees in 1944 with a focus on

auditory perception Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory ...

. Following the completion of his studies in 1944, he enlisted in the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

, initially serving as a radar technician at the

Anacostia Naval Station Anacostia is a historic neighborhood in Southeast Washington, D.C. Its downtown is located at the intersection of Good Hope Road and Martin Luther King Jr. Avenue. It is located east of the Anacostia River, after which the neighborhood is nam ...

. He was later relocated to Tsingtao in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

, where he was stationed on the

seaplane tender A seaplane tender is a boat or ship that supports the operation of seaplanes. Some of these vessels, known as seaplane carriers, could not only carry seaplanes but also provided all the facilities needed for their operation; these ships are rega ...

USS ''Chincoteague''. He attended

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of highe ...

after completing his military service in 1946, and was awarded a Ph.D. in 1949. His thesis showed that the connections between the

cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory o ...

and the cerebral cortex could be monitored using electrodes placed on the scalp, without requiring cranial surgery.

University of California, Berkeley

Rosenzweg was hired by the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant un ...

in 1949 as an assistant professorship in physiological psychology, and remained on its faculty until he retired in 1991.Carey, Benedict
"Mark Rosenzweig, Brain Researcher, Is Dead at 86"
''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

'', August 11, 2009. Accessed August 12, 2009. Dissatisfied with existing textbooks in biological psychology, he and colleague Arnold Leiman wrote a textbook in the 1980s that is still in print. Rosenzweig initiated experimental research upon enriched environment and the brain. Donald O. Hebb, in 1947, had found that rats raised as pets performed better on problem solving tests than rats raised in cages. But his research did not investigate the brain directly nor use standardized impoverished and enriched environments. Mark Rosenzweig with his colleagues

David Krech David Krech (March 27, 1909 – July 14, 1977) was a Polish-born American experimental and social psychologist who lectured predominately at the University of California, Berkeley. Throughout his education and career endeavors, Krech was with man ...

, Edward Bennett and Marian Diamond started this research in the late 1950s by comparing single rats in normal cages, and those placed in ones with toys, ladders, tunnels, running wheels in groups. They found that growing up in enriched environments affected activity of the enzyme cholinesterase in the brain. This work led in 1962 to the discovery that environmental enrichment increased

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting o ...

volume. He published details of his research in a book ''Enriched and Impoverished Environments: Effects on Brain and Behavior'' in 1987. These findings contradicted the prevailing scientific theory that the brain's structure was fixed before adulthood and that later learning and experience did not affect its structure. Later research confirmed that the changes occurred in adulthood and were not tied to differences in diet.

Neurobiologist A neuroscientist (or neurobiologist) is a scientist who has specialised knowledge in neuroscience, a branch of biology that deals with the physiology, biochemistry, psychology, anatomy and molecular biology of neurons, neural circuits, and glial c ...

James McGaugh James L. McGaugh (born December 17, 1931) is an American neurobiologist and author working in the field of learning and memory. He is a Distinguished Professor Emeritus in the Department of Neurobiology and Behavior at the University of Califor ...

credited Rosenzweig's research with having "laid to rest the idea that the brain is fixed in terms of its composition; that's now regarded as nonsense" with the subject of research changing to how, not if, the brain changes based on experience. Rozenzweig was the co-editor of the ''

Annual Review of Psychology The ''Annual Review of Psychology'' is a peer-reviewed academic journal that publishes review articles about psychology. First published in 1950, its longest-serving editors have been Mark Rosenzweig (1969–1994) and Susan Fiske (2000&ndas ...

'' with Paul H. Mussen from 1969 to 1974 and with Lyman Porter from 1975 to 1994. Rosenzweig retired from UC Berkeley in 1991. The

American Psychological Association The American Psychological Association (APA) is the largest scientific and professional organization of psychologists in the United States, with over 133,000 members, including scientists, educators, clinicians, consultants, and students. It ha ...

recognized him with its Distinguished Scientific Contribution Award in 1982.

Personal life and death

A resident of

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and E ...

, Rosenzweig died at his home at age 86 of

renal failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

on July 20, 2009. He was survived by two daughters, a son, six grandchildren and four great-grandchildren. He married his French-born wife, the former Janine Chappat, in the summer of 1947. She had studied anthropology and education at the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

and had been visiting the United States when they met. She died in April 2008 after they had been married for 60 years.

References

{{DEFAULTSORT:Rosenzweig, Mark 1922 births 2009 deaths American people of German-Jewish descent 20th-century American psychologists Deaths from kidney failure Harvard University alumni Scientists from Rochester, New York People from Berkeley, California United States Navy sailors 20th-century American Jews University of California, Berkeley faculty University of Rochester alumni Members of the United States National Academy of Sciences Jewish physicians Annual Reviews (publisher) editors 21st-century American Jews