• Choose a category
• All
• Classic-Fiction

By Root 1040 0

taint of religion and superstition. What James had identified as central topics—“the stream of thought,” “the consciousness of self,” the perception of time and space, imagination, reasoning, and will—had no place in Pavlov’s laboratory. All a scientist could observe was behavior, and this, at least, could be recorded and measured. The behaviorists, particularly John B. Watson in the United States and then, most famously, B. F. Skinner, made a science based on stimulus and response: food pellets, bells, electric shocks; salivation, lever pressing, maze running. Watson said that the whole purpose of psychology was to predict what responses would follow a given stimulus and what stimuli could produce a given behavior. Between stimulus and response lay a black box, known to be composed of sense organs, neural pathways, and motor functions, but fundamentally off limits. In effect, the behaviorists were saying yet again that the soul is ineffable. For a half century, their research program thrived because it produced results about conditioning reflexes and controlling behavior.

Behaviorists said, as the psychologist George Miller put it afterward: “You talk about memory; you talk about anticipation; you talk about your feelings; you talk about all these mentalistic things. That’s moonshine. Show me one, point to one.”♦ They could teach pigeons to play ping-pong and rats to run mazes. But by midcentury, frustration had set in. The behaviorists’ purity had become a dogma; their refusal to consider mental states became a cage, and psychologists still wanted to understand what the mind was.

Information theory gave them a way in. Scientists analyzed the processing of information and built machines to do it. The machines had memory. They simulated learning and goal seeking. A behaviorist running a rat through a maze would discuss the association between stimulus and response but would refuse to speculate in any way about the mind of the rat; now engineers were building mental models of rats out of a few electrical relays. They were not just prying open the black box; they were making their own. Signals were being transmitted, encoded, stored, and retrieved. Internal models of the external world were created and updated. Psychologists took note. From information theory and cybernetics, they received a set of useful metaphors and even a productive conceptual framework. Shannon’s rat could be seen not only as a very crude model of the brain but also as a theory of behavior. Suddenly psychologists were free to talk about plans, algorithms, syntactic rules. They could investigate not just how living creatures react to the outside world but how they represent it to themselves.

Shannon’s formulation of information theory seemed to invite researchers to look in a direction that he himself had not intended. He had declared, “The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point.” A psychologist could hardly fail to consider the case where the source of the message is the outside world and the receiver is the mind.

Ears and eyes were to be understood as message channels, so why not test and measure them like microphones and cameras? “New concepts of the nature and measure of information,” wrote Homer Jacobson, a chemist at Hunter College in New York, “have made it possible to specify quantitatively the informational capacity of the human ear,”♦ and he proceeded to do so. Then he did the same for the eye, arriving at an estimate four hundred times greater, in bits per second. Many more subtle kinds of experiments were suddenly fair game, some of them directly suggested by Shannon’s work on noise and redundancy. A group in 1951 tested the likelihood that listeners would hear a word correctly when they knew it was one of just a few alternatives, as opposed to many alternatives.♦ It seemed obvious but had never been done. Experimenters explored the effect of trying to understand two conversations at once. They began considering how much information an