International Encyclopedia of Systems and Cybernetics

St. BEER described the brain in cybernetic terms as follows: "We have in the cranium a slightly alkaline three-pound electrochemical computer running on glucose at about 25 watts. This computer contains some ten thousand million (that's 10) logical elements called neurons, operating on a basic scanning rhythm of ten cycles per second. Then this is a high-variety dynamic system all right; but it really is finite. It follows from ASHBY's law that we can recognize patterns up to a certain limit, and not beyond. Thus if something is going on that involves a higher variety than the brain commands, we shall not recognize what it is. This is the old constraint of requisite variety" (1974, p.58).

BEER adds the following: "About a quart of blood (about one seventh of the circulation) flows through the brain every minute, and is heated about one degree Fahrenheit. That takes about 25 watts.

"The resting state of the brain, called the alpha state, is characterized by the alpha rhythm, which tends to be stable at around ten cycles" (p.67).

Of course, in 1974, research on networks and connection machines was just starting. The analogies between the brain and the computer (digital or parallel, or both?) surely needs still more careful scrutiny.

From another angle, related to the general organization of the brain, it would seem that it is at the same time localized (with specific perceptive and active areas), distributed (even a seemingly global function, as for instance sight, is the global result of a synchronic synthesis of distinct perceptions of limits, position, shape, motion, depth, colors, etc.)… and hierarchical, in the sense that, admitting the modular character of brain organization, brain works in a coordinated way (Philippe LAMBERT on Xavier SERON's cognitive neuropsychology - 1999. p.39-43 - Hemai PARTHASARATHY, 1999, p.29-31).

However "hierarchical" does not imply an all powerful and precisely localized organizer. It seems to respond to a kind of chaotic determinism through multiple simultaneous neuronal interactions, within diffuse limits, leading to autopoiesis

This could better explain creativity, learning, and also partial readaptation after some disability (as a stroke, for example).

→ Algorithm (Back propagation); Algorithm (Framing); Algorithm (Iterative refinement); Algorithmization by selection; Information; Nervous system and brain, Memory (Distributed); Taxon memory