Walter Pitts
Encyclopedia
Cognitive psychology
Cognitive psychology is a subdiscipline of psychology exploring internal mental processes.It is the study of how people perceive, remember, think, speak, and solve problems.Cognitive psychology differs from previous psychological approaches in two key ways....
.
He proposed landmark theoretical formulations of neural activity and emergent processes that influenced diverse fields such as cognitive sciences and psychology
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
, philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
s, computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
, artificial neural network
Artificial neural network
An artificial neural network , usually called neural network , is a mathematical model or computational model that is inspired by the structure and/or functional aspects of biological neural networks. A neural network consists of an interconnected group of artificial neurons, and it processes...
s, cybernetics and artificial intelligence
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
, together with what has come to be known as the generative sciences. He is best remembered for having written along with Warren McCulloch, a seminal paper entitled "A Logical Calculus of Ideas Immanent in Nervous Activity" (1943). This paper proposed the first mathematical model of a neural network
Neural network
The term neural network was traditionally used to refer to a network or circuit of biological neurons. The modern usage of the term often refers to artificial neural networks, which are composed of artificial neurons or nodes...
. The unit of this model, a simple formalized neuron, is still the standard of reference in the field of neural networks. It is often called a McCulloch–Pitts neuron.
Early life
Walter Pitts was born in Detroit. MichiganMichigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
on April 23, 1923, the son of Walter and Marie (née Welsia). He was an autodidact
Autodidacticism
Autodidacticism is self-education or self-directed learning. In a sense, autodidacticism is "learning on your own" or "by yourself", and an autodidact is a person who teaches him or herself something. The term has its roots in the Ancient Greek words αὐτός and διδακτικός...
who taught himself logic
Logic
In philosophy, Logic is the formal systematic study of the principles of valid inference and correct reasoning. Logic is used in most intellectual activities, but is studied primarily in the disciplines of philosophy, mathematics, semantics, and computer science...
and mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
and was able to read a number of languages including Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
and Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
. At the age of 12 he spent three days in a library reading Principia Mathematica
Principia Mathematica
The Principia Mathematica is a three-volume work on the foundations of mathematics, written by Alfred North Whitehead and Bertrand Russell and published in 1910, 1912, and 1913...
and sent a letter to Bertrand Russell
Bertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS was a British philosopher, logician, mathematician, historian, and social critic. At various points in his life he considered himself a liberal, a socialist, and a pacifist, but he also admitted that he had never been any of these things...
pointing out what he considered serious problems with the first half of the first volume. Russell was appreciative and invited him to study in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. Although this offer was not taken up, Pitts decided to become a logician.
Academic career
Pitts probably continued to correspond with Betrand Russell; in any case, since his father and brothers were unappreciative of his intellectual endeavors and wanted him to leave school to go to work, he ran away from home at the age of 15 to attend Russell's lectures at the University of ChicagoUniversity of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
. He stayed there, without registering as a student. While there, in 1938 he met Jerome Lettvin
Jerome Lettvin
Jerome Ysroael Lettvin was a cognitive scientist and professor Emeritus of Electrical and Bioengineering and Communications Physiology at the Massachusetts Institute of Technology . He is best known as the author of the 1959 paper, "What the frog's eye tells the frog's brain", one of the most...
, a pre-medical
Pre-medical
Pre-medical is a term used to describe a track an undergraduate student in the United States pursues prior to becoming a medical student...
student, and the two became close friends. Bertrand Russell was a visiting professor at the University of Chicago in the Fall of 1938, and he directed Pitts to go study there with the logician Rudolf Carnap
Rudolf Carnap
Rudolf Carnap was an influential German-born philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism....
. Pitts met Carnap at Chicago by walking into his office during office hours, and presenting him with an annotated version of Carnap's recent book on logic, The Logical Syntax of Language. Since Pitts did not introduce himself, Carnap spent months searching for him, and, when he found him, he obtained for him a menial job at the university and had Pitts study with him. Pitts at the time was homeless and without income. He mastered Carnap's abstract logic, then met with and was intrigued by the work of the Russian mathematical physicist Nicolas Rashevsky
Nicolas Rashevsky
Nicolas Rashevsky was a Ukrainian-American theoretical biologist who pioneered mathematical biology, and is also considered the father of mathematical biophysics and theoretical biology.-Academic career:...
, who was also at Chicago and was the founder of mathematical biophysics
Biophysics
Biophysics is an interdisciplinary science that uses the methods of physical science to study biological systems. Studies included under the branches of biophysics span all levels of biological organization, from the molecular scale to whole organisms and ecosystems...
, remodeling biology on the structure of the physical sciences and mathematical logic. Pitts also worked closely with the mathematician Alston Householder
Alston Scott Householder
Alston Scott Householder was an American mathematician who specialized in mathematical biology and numerical analysis, inventor of the Householder transformation and of Householder's method...
who was part of Rashevsky's group.
Later Warren McCulloch also arrived at the University of Chicago, and in early 1942 invited Pitts, who was still homeless, together with Lettvin to live with his family. In the evenings McCulloch and Pitts collaborated. Pitts was familiar with the work of Gottfried Leibniz
Gottfried Leibniz
Gottfried Wilhelm Leibniz was a German philosopher and mathematician. He wrote in different languages, primarily in Latin , French and German ....
on computing and they considered the question of whether the nervous system could be considered a kind of universal computing device as described by Leibniz. This led to their seminal neural network
Neural network
The term neural network was traditionally used to refer to a network or circuit of biological neurons. The modern usage of the term often refers to artificial neural networks, which are composed of artificial neurons or nodes...
s paper A Logical Calculus of Ideas Immanent in Nervous Activity.
In 1943 Lettvin introduced Pitts to Norbert Wiener
Norbert Wiener
Norbert Wiener was an American mathematician.A famous child prodigy, Wiener later became an early researcher in stochastic and noise processes, contributing work relevant to electronic engineering, electronic communication, and control systems.Wiener is regarded as the originator of cybernetics, a...
at MIT, who had recently lost his "right-hand man". Their first meeting, where they discussed Wiener's proof of the ergodic theorem
Ergodic theory
Ergodic theory is a branch of mathematics that studies dynamical systems with an invariant measure and related problems. Its initial development was motivated by problems of statistical physics....
, went so well that Pitts moved to Boston to work with Wiener. Pitts was a special student of Weiner's at MIT.
In 1944 Pitts was hired by Kellex Corporation (later acquired in 1950 by Vitro Corporation
Vitro Corporation
Vitro Corporation was a major United States defense contractor which became part of BAE Systems in 1999.-History:Vitro was incorporated in 1950 as the Vitro Manufacturing Company. Its main product was slide transparencies for overhead projectors...
) in New York City, part of the Atomic Energy Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
.
From 1946, Pitts was a core member and involved with the Macy conferences
Macy conferences
The Macy Conferences were a set of meetings of scholars from various disciplines held in New York by the initiative of Warren McCulloch and the Josiah Macy, Jr. Foundation from 1946 to 1953...
whose principal purpose was to set the foundations for a general science of the workings of the human mind.
In 1951 Wiener convinced Jerry Wiesner to hire some physiologists of the nervous system. A group was established with Pitts, Lettvin, McCulloch, and Pat Wall. Pitts wrote a large thesis on the properties of neural nets connected in three dimensions. Lettvin described him as "in no uncertain sense the genius of the group … when you asked him a question, you would get back a whole textbook". Pitts was also described as an eccentric, refusing to allow his name to be made publicly available. He refused all offers of advanced degrees or official positions at MIT as he would have to sign his name.
Pitts was part of the Research Laboratory of Electronics at MIT
Research Laboratory of Electronics at MIT
The Research Laboratory of Electronics at the Massachusetts Institute of Technology was founded in 1946 as the successor to the famed MIT Radiation Laboratory of World War II....
from 1952-1969.
Emotional trauma and decline
Wiener suddenly turned against McCulloch, on account of his wife Margaret Wiener who hated McCulloch, and broke off relations with anyone connected to him including Pitts. This sent Walter Pitts into 'cognitive suicide', a gradual but steep decline into social isolation, from which he never recovered. He burnt the manuscript on three dimensional networks and took little further interest in work. The only exception was a collaboration with Robert Gesteland which produced a paper on olfactionOlfaction
Olfaction is the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates...
. Pitts died in 1969 of bleeding esophageal varices, a condition usually associated with alcoholism.
Publications
- Walter Pitts, "Some observations on the simple neuron circuit", Bulletin of Mathematical Biology, Volume 4, Number 3, 121-129, 1942.
- Warren McCulloch and Walter Pitts, "A Logical Calculus of Ideas Immanent in Nervous Activity", 1943, Bulletin of Mathematical Biophysics 5:115-133.
- Warren McCulloch and Walter Pitts, "On how we know universals: The perception of auditory and visual forms", 1947, Bulletin of Mathematical Biophysics 9:127-147.
- Howland, R., Jerome Lettvin, Warren McCulloch, Walter Pitts, and P. D. Wall, "Reflex inhibition by dorsal root interaction", 1955, Journal of Neurophysiology 18:1-17.
- Wall, P. D., Warren McCulloch, Jerome Lettvin and Walter Pitts, "Effects of strychnine with special reference to spinal afferent fibres", 1955, Epilepsia Series 3, 4:29-40.
- Jerome Lettvin, Humberto MaturanaHumberto MaturanaHumberto Maturana is a Chilean biologist and philosopher. He is considered a member of the second wave of cybernetics, known for developing a theory of autopoiesis about the nature of reflexive feedback control in living systems.- Biography :After completing secondary school at the Liceo Manuel de...
, Warren McCulloch, and Walter Pitts, "What the Frog's Eye Tells the Frog's Brain", 1959, Proceedings of the Institute of Radic Engineers 47: 1940-1959 - Humberto Maturana, Jerome Lettvin, Warren McCulloch, and Walter Pitts, "Anatomy and physiology of vision in the frog", 1960, Journal of General Physiology, 43:129—175
- Robert Gesteland, Jerome Lettvin and Walter Pitts, "Chemical Transmission in the Nose of the Frog", 1965, J.Physiol. 181, 525-529.
Further reading
- Piccinini, Gualtiero, "The First Computational Theory of Mind and Brain: A Close Look at McCulloch and Pitts's 'Logical Calculus of Ideas Immanent in Nervous Activity'", Synthese 141: 175–215, 2004. Kluwer Academic PublishersWolters KluwerWolters Kluwer N.V. is a global information services and publishing company. The company provides products and services for professionals in the health, tax, accounting, corporate, financial services, legal and regulatory sectors...
External links
- "Walter Pitts", website of Professor Charles Wallis, California State University Long Beach, Department of Cognitive Science, accessed 30 Jan. 2009 (archived 2009)