Karl Lashley
Karl Spencer Lashley | |
---|---|
Born | June 7, 1890 |
Died | August 7, 1958 Poitiers, France | (aged 68)
Alma mater | Johns Hopkins University |
Known for | Learning and memory |
Awards |
|
Scientific career | |
Fields | Herbert S. Jennings |
Karl Spencer Lashley (June 7, 1890 – August 7, 1958) was an American psychologist and
Early life and education
Lashley was born on June 7, 1890, in the town of Davis, West Virginia. He was the only child of Charles and Maggie Lashley. He grew up in a middle-class family with a reasonably comfortable life. Lashley's father held various local political positions. His mother was a stay-at-home parent, and had a vast collection of books in the home. She brought in women from the community, whom she would teach various subjects. This is no doubt what gave Lashley his love of learning. Lashley has always held his family in high regard. He has said that his father was a kind man.[citation needed]
Lashley's mother was a strong advocate of schooling, and she encouraged Lashley intellectually from an early age. Lashley was a very active boy, both physically and mentally. He was able to read by the age of four. His favorite thing to do as a child was to wander through the woods and collect animals, like butterflies and mice. He spent most of his childhood alone. Lashley did not have many friends. The reasons for his lack of friendships is unclear. Lashley graduated high school at age 14.
Lashley enrolled at West Virginia University, where he had originally intended to become an English major. He took a course in zoology, however, and switched his major to zoology due to his interactions with the professor John Black Johnston. Lashley wrote, "Within a few weeks in his class I knew that I had found my life's work".[3]
After obtaining his
At Hopkins, Lashley minored in psychology under John B. Watson, whom he continued to work closely with him after receiving his PhD. It was during this time that Lashley worked with Shepherd Ivory Franz and was introduced to his training/ablation method. Watson had a great deal of influence on Lashley. Together the two conducted field experiments and studied the effects of different drugs on maze learning of rats.[4] Watson helped Lashley to focus on specific problems in learning and experimental investigation, followed by locating the area of the cerebrum involved in learning and discrimination.
Career
Lashley's career began with research concerning brain mechanisms and how they were related to sense receptors. He also conducted work on instinct as well as color vision. He studied many animals and primates, which had been an interest since his freshman year at college.
Lashley worked at the
Lashley's most influential research centered around the cortical basis of learning and discrimination. He researched this by looking at the measurement of behavior before and after specific, carefully quantified, induced brain damage in rats. Lashley trained rats to perform specific tasks (seeking a food reward), then lesioned specific areas of the rats' cortex, either before or after the animals received the training. The cortical lesions had specific effects on acquisition and retention of knowledge, but the location of the removed cortex had no effect on the rats' performance in the maze. This led Lashley to conclude that memories are not localized, but that they are widely distributed across the cortex. Today we know that distribution of engrams does in fact exist, but that the distribution is not equal across all cortical areas, as Lashley assumed.[5][6] His study of V1 (primary visual cortex) led him to believe that it was a site of learning and memory storage (i.e. an engram) in the brain. He reached this erroneous conclusion due to imperfect lesioning methods.
By the 1950s, two separate principles had grown out of Lashley's research:
Later life
In February 1954, while doing his teaching at Harvard, Lashley unexpectedly collapsed and was hospitalized. He was diagnosed with hemolytic anemia and put on a cortisone treatment. This eventually began to soften his vertebrae, and as a result a splenectomy was performed. Lashley was on the road to a full recovery until his trip to France with his wife Clair, where he once again unexpectedly collapsed, but this time to his death on August 7, 1958.[4]
Honors
Lashley was elected to many scientific and philosophical societies, including the
Lashley was awarded honorary Doctor of Science degrees from the
Criticisms
Lashley had a reputation as an objective scientist, but Nadine Weidman has tried to expose him as racist and a genetic determinist. But Donald Dewsbury and others, have disputed the claim that he was a genetic determinist, citing research of Lashley's in which he found evidence of both genetic and environmental influences on organisms. Dewsbury does admit however, that Lashley was quite racist. He cites a line from a letter that Lashley wrote to a German colleague which reads: "Too bad that the beautiful tropical countries are all populated by negros. Heil Hitler and Apartheit!"[11] This line alone would leave little debate on this matter, but he cites others as well.
Notable publications
- 1923 "The behavioristicinterpretation of consciousness." Psychological Review
- 1929 "Brain mechanisms and intelligence."
- 1930 "Basic neural mechanisms in behavior." Psychological Review
- 1932 "Studies in the dynamics of behavior." University of Chicago Press.
- 1935 "The mechanism of vision", Part 12: Nervous structures concerned in the acquisition and retention of habits based on reactions to light. Comparative Psychology Monographs 11: 43–79.
- 1943 "Studies of Cerebral Function in Learning", Journal of Comparative Neurology vol. 79.
- 1950 "In search of the engram." Society of Experimental Biology Symposium 4: 454–482.
- 1951 "The problem of serial order in behavior." Cerebral Mechanisms in Behavior.
See also
References
- ^ S2CID 73205669.
- S2CID 145668721.
- ^ Beach, Frank A. (1961). Karl Spencer Lashley 1890-1958 (PDF). Washington, D.C.: National Academy of Sciences. p. 9.
- ^ a b c d e http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/lashley-karl.pdf [bare URL PDF]
- PMID 20569648.
- ^ "Karl Lashley". Archived from the original on 2019-05-11. Retrieved 2013-11-28.
- ^ "About the Department § the Department of Psychology". Archived from the original on 2012-04-07. Retrieved 2013-11-28.
- ISBN 978-3-319-56782-2.
- ^ "Award Ceremony: Karl Spencer Lashley Award, 2008." American Philosophical Society. "Award Ceremony | American Philosophical Society". Archived from the original on 2010-08-01. Retrieved 2010-06-20.
- ^ "Daniel Giraud Elliot Medal". National Academy of Sciences. Archived from the original on August 1, 2012. Retrieved 15 February 2011.
- PMID 12115784.
Further reading
- Dewsbury, Donald A (2002), "Constructing representations of Karl Spencer Lashley.", Journal of the History of the Behavioral Sciences, vol. 38, no. 3, pp. 225–45, PMID 12115784
- Dewsbury, D A (2002), "The Chicago Five: a family group of integrative psychobiologists.", History of Psychology, vol. 5, no. 1 (published Feb 2002), pp. 16–37, PMID 11894885
- Sapetskiĭ, A O (1999), "[A physiologist's dialog with a psychologist]", Zhurnal Vyssheĭ Nervnoĭ Deiatelnosti Imeni I P Pavlova, vol. 49, no. 6, pp. 909–18, PMID 10693270
- Bruce, D (1986), "Lashley's shift from bacteriology to neuropsychology, 1910–1917, and the influence of Jennings, Watson, and Franz.", Journal of the History of the Behavioral Sciences, vol. 22, no. 1 (published Jan 1986), pp. 27–44, PMID 3511136
- Roofe, P G (1970), "Some letters from the Herrick-Lashley correspondence.", Neuropsychologia, vol. 8, no. 1 (published Jan 1970), pp. 3–12, PMID 4941968
- CARMICHAEL, L (1959), "Karl Spencer Lashley, experimental psychologist.", PMID 13658968
- WALSHE, F M (1958), "Karl S. Lashley.", Neurology, vol. 8, no. 11 (published Nov 1958), p. 870, PMID 13590401
- Weidman, Nadine (2002), "The depoliticization of Karl Lashley: A response to Dewsbury.", Journal of the History of the Behavioral Sciences, vol. 38, no. 3, pp. 247–53, discussion 255–7, PMID 12115785