SLEEP AND BRAIN EXPERIMENTS.

Gisborne Times, Volume XXVIII, Issue 2769, 26 March 1910, Page 3 (Supplement)

SLEEP AND BRAIN EXPERIMENTS.

Experiments regarding the brain and the mysteries of sleep recently made by Michigan University are detailed (says the New York correspondent- of the “Daily Telegraph”) by Proiessor We ally, who declares authoratively that the investigations have destroyed many accepted theories. The accepted theory of sleep has been the lessening of the blood-pressure in the brain. The experiments showed directly opposite conditions. By delicate and most- careful measurements the following results \vcre4 tabulated: —The size or volume of the brain increases -when the individual goes to sleep, and decreases when be awakens. Un this point it was noted that in some cases the brain became, smaller at first, and increased 4$ the sleep became deeper. Very striking was the evidence that the size of the arterial pulse in tlie brain increases steadily with the increase in the volume —i.e.,'that the dilating of the arteries after each beat of the heart is more pronounced. This is particularly true when jblie subject is propped up. As the sleep passes off the brain volume decreases, but then the blood increases. These results show tnat whatever sleep may be caused by, it is not a lessening of the blood-supply to the brain, for there is no such lessening.