Karl Spenser Lashley

Karl Spenser Lashley

American psychologist
Date of Birth: 07.06.1890
Country: USA

  1. Biography of Karl Spencer Lashley
  2. Karl Spencer Lashley passed away in Paris on August 7, 1958.

Biography of Karl Spencer Lashley

Karl Spencer Lashley (1890–1958) was an American psychologist known for his experimental work in the field of brain mechanisms and intelligence. He was born on June 7, 1890, in Davis, West Virginia. Lashley received his education at the University of West Virginia and the University of Pittsburgh. In 1914, he defended his dissertation in zoology at Johns Hopkins University.

Lashley began his career as a faculty member at Johns Hopkins University and St. Elizabeth's Hospital in Washington, D.C. He later worked at the University of Minnesota (1917–1924), the Research Foundation for the Study of Behavior in Chicago (1926–1929), and the University of Chicago (1929–1935). In 1935, he accepted an invitation from Harvard University, where he remained until 1955.

In 1942, Lashley became the director of the Primate Biology Laboratory at Orange Park, Florida, succeeding Robert Yerkes. This laboratory was home to renowned scientists such as Donald Hebb, Roger Sperry, and Karl Pribram.

Lashley's experimental findings were published in his book "Brain Mechanisms and Intelligence" in 1929. At that time, the cerebral cortex was believed to consist of separate but interconnected areas, each with its specific function. It was thought that mental processes, such as the emergence of conditioned reflexes, were associated with specific localized structures.

Lashley proposed two concepts that gained widespread recognition. In his experiments, when a specific area of the cerebral cortex in an animal was damaged, another area would take over its functions. This concept, known as equipotentiality, described the ability of the remaining part of the cortex to compensate for the loss.

The concept of mass action described one of the consequences of cerebral cortex damage: the quality of task performance decreased in proportion to the volume of destruction and did not necessarily depend on the localization of the injury.

Neither of these concepts contradicted Lashley's main approach, which stated that different brain areas were responsible for different functions. However, according to his observations, localization had less influence on more complex mental processes.

Karl Spencer Lashley passed away in Paris on August 7, 1958.