Because of the “all-or-none” character of nervous activity, neural events and the relations among them can be treated by means of propositional logic. It is found that the behavior of every net can be described in these terms, with the addition of more complicated logical means for nets containing circles; and that for any logical expression satisfying certain conditions, one can find a net behaving in the fashion it describes. It is shown that many particular choices among possible neurophysiological assumptions (...) are equivalent, in the sense that for every net behaving under one assumption, there exists another net which behaves under the other and gives the same results, although perhaps not in the same time. Various applications of the calculus are discussed. (shrink)

Writings by a thinker—a psychiatrist, a philosopher, a cybernetician, and a poet—whose ideas about mind and brain were far ahead of his time. Warren S. McCulloch was an original thinker, in many respects far ahead of his time. McCulloch, who was a psychiatrist, a philosopher, a teacher, a mathematician, and a poet, termed his work “experimental epistemology.” He said, “There is one answer, only one, toward which I've groped for thirty years: to find out how brains work.” Embodiments of Mind, (...) first published more than fifty years ago, teems with intriguing concepts about the mind/brain that are highly relevant to recent developments in neuroscience and neural networks. It includes two classic papers coauthored with Walter Pitts, one of which applies Boolean algebra to neurons considered as gates, and the other of which shows the kind of nervous circuitry that could be used in perceiving universals. These first models are part of the basis of artificial intelligence. Chapters range from “What Is a Number, that a Man May Know It, and a Man, that He May Know a Number,” and “Why the Mind Is in the Head,” to “What the Frog's Eye Tells the Frog's Brain” (with Jerome Lettvin, Humberto Maturana, and Walter Pitts), “Machines that Think and Want,” and “A Logical Calculus of the Ideas Immanent in Nervous Activity” (with Walter Pitts). Embodiments of Mind concludes with a selection of McCulloch's poems and sonnets. This reissued edition offers a new foreword and a biographical essay by McCulloch's one-time research assistant, the neuroscientist and computer scientist Michael Arbib. (shrink)

Modern knowledge of servo systems and computing machines makes it possible to specify a circuit that can and will induce the rules and winning moves in a game like chess when they are given only ostensibly, that is, by playing against opponents who quit when illegal or losing moves are made. Such circuits enjoy a value social in the sense that it is shared by the players.La connaissance moderne des servomécanismes et des machines à calculer permet de concevoir un circuit (...) qui pourra suivre des règles et décider les coups décisifs dans un jeu comme le jeu d'échecs tout au moins quand les coups sont joués de faÇon apparente, c'est-à-dire contre des adversaires qui abandonneront dans le cas de coups irréguliers ou de coups absurdes.De tels circuits possèdent une „valeur” sociale dans la mesure où elle est partagée par les autres joueurs.Moderne Kenntnissen im Gebiete von Folgegeraeten und Rechenmaschinen ermoeglichen es einen elektrischen Kreis aufzuwerfen, der die Regeln und gewinnbringende Zuege eines Spieles wie Schach induktiv erfassen kann und wird, wenn diese Regeln und Zuege nur ostensiv gegeben sind; d.h. indem mit Gegnern gespielt wird, die das Spiel einstellen sobald regelwidrige oder verlustbringende Zuege gemacht werden. Solche Kreise schaffen demnach einen Wert, der gesellschaftlich in dem Sinn ist, dass er auch von den Mitspielern geteilt wird. (shrink)