"Time is telescoped to such an extent and we have so many stimuli that the patterns of memory are broken up," is Doctor Bill's way of putting it. "The pace at which modern society lives has much to do with the situation."

What psychologists call "retroactive inhibition"-involuntaryis the main cause of forgetting. Learning a second thing may cause us to forget the first. For example, important inventions and discoveries we--e once few and far between. But today we have no time in which to accept the jet-propulsion plane before we are told of the atomic bomb.

Emotional inhibition is temporary and an insignificant factor, but there is more of it today than formerly, thinks Doctor Bills. Poor fixation also must be considered, because it is easy to forget something which we have not learned well at the outset. The great number of things to be remembered these days also affects fixation. The fading out of memory is not a major factor.

To illustrate that mere passing of time need not cause forgetfulness, Doctor Bills cites a test involving sleep. In the first part of a test a subject learned something, slept an hour and was awakened. In the second part of the test he learned something, slept eight hours, and then was awakened. In both cases he remembered equally well, despite the seven-hour difference in sleep. In other words, mere passage of time need not cause forgetfulness.

If that same subject remains awake eight hours, he will forget 60 per cent of what he has learned. This proves that "retroactive inhibition" is caused not by mere passage of time but by what the brain does between learning and attempting to recall what was learned.-W. K. N. Y. Times