Story of Psychology - Morton Hunt [185]
In a variation, Wertheimer used a vertical line and a horizontal line. At the right speed his subjects saw one line rotating back and forth through 90 degrees. In another variation he used lights; these, at the critical speed, appeared to be a single light moving. In still others he used multiple lines, different colors, and different shapes, and in every case was able to produce the illusion of motion. Even after he told his three subjects what was happening, they could not make themselves not see the motion. Through still other variations, Wertheimer ruled out any possibility that the phenomenon was due to eye movements or retinal afterimages.
The illusion, he concluded, was a “psychic state of affairs,” which he called the φ phenomenon. The letter phi, he said, “designates something that exists outside the perceptions of a and b,” resulting from a “psychological short-circuit” in the brain.4 The φ phenomenon, he suggested, resulted from “a psychological short-circuit” in the brain between the two areas stimulated by the nerve impulses coming from the retinal areas stimulated by a and b.
This physiological hypothesis did not stand up in later research; what did was Wertheimer’s theory that the illusion of motion takes place not at the level of sensation, in the retina, but of perception, in the mind, where incoming discrete sensations are seen as an organized unity with a meaning of its own. Wertheimer called such an overall perception a Gestalt, a German word that means form, shape, or configuration but that he used to mean a set of sensations perceived as a meaningful whole.
Seemingly, he had spent months of work to explain a trivial illusion. In actuality, he and his co-workers had sown the seed of the Gestalt school of psychology, a movement that would enrich and broaden psychology both in Germany and the United States.*
The Rediscovery of the Mind
Wertheimer’s theory that the mind adds structure and meaning to incoming sensations was distinctly out of step with the antimentalist psychology that had been dominant in Germany for nearly half a century and in America for a generation.
His theory was also out of step with the Zeitgeist of 1910, which centered on the transformation of life and thought by the physical sciences and technology. The electric light was radically altering nighttime in cities and even remote towns, the automobile was changing the habits of nations, airplanes were becoming capable of sustained flight (Louis Blériot had flown across the English Channel), Marie Curie had just isolated radium and polonium, Rutherford was working out his theory of atomic structure, Zeppelin passenger service had recently begun, and Lee De Forest had lately patented the radio tube. The New Psychology was in harmony with such developments; mentalist psychology seemed more than ever metaphysical, unscientific, and passé.
But for some years a number of psychologists had considered Wundtian psychology barren and confining because it did not deal with complex forms of experience such as emotions, thinking, learning, and creativity—the most important aspects of human life. James, Galton, Binet, Freud, and the members of the Würzburg School, though they had dissimilar concerns, were all interested in and had been investigating phenomena that could be explained only in terms of higher mental processes.
In addition, other researchers had been turning up bits of evidence that perceptions are not identical with the sensations received by the retina or other sense organs but are the mind’s interpretation of the data in those sensations.
As far back as 1890, Christian von Ehrenfels,