INTENSITY OF SLEEP

Manawatu Times, 4 May 1926, Page 5

INTENSITY OF SLEEP

Vi MEASURED BY SCIENTIST. A definite step in unravelling tlio mystery of sleep, which has baffled scientists from earliest times, nas been made by Dr. Curt P. Richter, or the Henry Phipps Psychintic Clinic Of John Hopkins University, U.S.A. With a string galvonometer anj specially constructed electrodes. _he has boccn able to tell how soundly a person is sleeping without awakening him. His experiments not only have shown that sleep is of two distinctly different kinds, but that there is a groat difference between real sleep and conditions in which certain types of mentally ill people appear to be asleep. His discoveries are reported in a paper entitled. "The Significance of Changes in the Electrical Resistance of the Body During Sleep,” which appears in the current issue of the Proceedings of the National Academy of Sciences. His researches showed that the resistance to an imperceptible electrical current sent from hand to hand during sleep was localised almost entirely in the skin. This resistance increased in one instance from 30,000 ohms when the subject was awake to 500,000 ohms when asleep. The current was applied by tne electrodes of sine covered with a thick kaolin paste mixed with saturated zinc sulphate solution. These were attached ti the hands and connected to the strong galvometer, designed to measure the smallest currents. The experiments showed that the intensity of the resistance varied directly with the intensity of sleep. It was discovered, however, that when sleep was not sound the resistance of the skin on the backs of the hands usually decreased. In these cases the subject was not refreshed by sleep. In the case of patients suffering from catatonic stupors, which so closely resemble sleep that it is impossible to tell by looking at the patient that he is not asleep, a very different condition was found. In these cases it was discovered v* that the paim-to-palm resistance of the hand was less than normal, ln- ' dicating an intense consciousness; while the resistance from back to back of the hand was very high, indicating complete muscular relaxation and lack of control. From those studies it is hoped that new light will bo thrown upon nervous conditions, not only of mentally ill patients, but of relatively normal people suffering from nervous strain.