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A Wizard and A Pioneer: William Grey Walter


Sir Winston Churchill in his history of the Second World War wrote a chapter on the “wizards” who had helped Britain win the war in the air by the development and use of radar. William Grey Walter (1910-1977) was one of those young wizards. He built autonomous robots that embodied the principle of goal-seeking and scanning. His robots demonstrated that brains are simpler than many of us have supposed.

We can study Dr. W.Grey Walter as a neurophysiologist first, then as a pioneer of cybernetics.

Neurophysiology and Brain Waves

In the book “Discussions on Child Development”, we can see how he was influenced by the Pavlovian Theories in his early studies. Dr. W.Grey Walter contributed great improvement to the technologies of electroencephalography(EEG), the brain waves. He found the interesting event of contingent negative variation (CNV), or readiness potential. This is a very slow change in electrical potential at and around the vertex of the head. This event is seen only after a warning signal had been given to a human subject, who would then plan a possible movement in anticipation of a second signal. That allows observer to predict a subject will make a response within the next half to one second, before the subject is aware of an intention to act.

He studied Alpha wave activities and proposed that the alpha represented 'scanning' by the brain in search of local centers of activity when none was present, and that it stopped when a 'target' was found in the cortex. This 50 year old hypothesis was and still is controversial, but it is still not disproven. Also he demonstrated the use of delta waves to locate brain tumors.

After the War, Dr W.Grey Walter combined his interests in the physiology of nervous system to the influence of environment on children and how children grew up. Later he extended this “nervous system/environment influence/children development” studies to further thinking. This would lead to our cybernetics scientist Grey Walter.

Cybernetics and Robot Tortoise

This are Grey's tortoises.

In 1951, Dr. W.Grey Walter displayed his `tortoises' at the Festival of Britain. His electric toy simulated two basic characteristics of animal behavior:goal-seeking and scanning. The designer-endowed goal was moderate illumination. One vacuum tube was used to simulate two interconnected neurons. The first sensor was a photocell and it was connected to the drive and steering motors. The second sensor was a contact switch that indicated that the turtle’s “shell” had bumped into something. The simple actions of stop, back up ,turn allowed the turtles to move around or avoid obstacles. They could wander a room and return to a hutch to recharge batteries. His two papers, “An Imitation of Life” in 1950, “A Machine that Learns” in 1951 and his book “The Living Brain” in 1963 were widely read and studied.

The technique he used are reflected in today’s biologically-inspired robots. These are the B.E.A.M philosophy. The acronym BEAM is standing for: Biology, Electronics, Aesthetics, Mechanics. Biology means we look the nature for inspirations, to solve our problems; Electronics is the technology for us to get our creations work; Aesthetics means that something “looks cool” rather than something crappy though they may work; Mechanics is an intelligent design such as your robot can get around without optical or touch switches.

Papers and Books

people/xinyu_chen/wgw.txt · Last modified: 2014/10/26 14:23 by xychen