MEASURING SLEEP

Greymouth Evening Star, 29 December 1934, Page 3

MEASURING SLEEP

RECORDS BY NEW DEVICE “I sleep like a log” may be your own evaluation of what happens when your head falls back on the pillow, but to Dr. Donald A. Laird of the Psychological Laboratory, Hamilton, NewYork, it means nothing. With his somnokinetograph (sleep movement recorder) ho finds no difficulty at all in proving that you twist and squirm I throughout your heaviest sleep. If j you do most of your twisting and squirming in the first, hour you are | what he calls a “diminuendo type,” I and if you become more and moie i restless as the night wears on you are | a “crescendo.” The records of the somnokinetograph place you where von belong as surely as your comp.ex- . ion and hair classify you as a blonde or a brunette. Despite its formidable mime the somnokinetograph is simple enough in principle. On top of your matt’, ess is n small brass plate. A thin rod (it passes through the mattress) and a fish line to connect the plate with the recorder. Lift your hand only tAVO inches, turn your head only an meh, and you unwittingly change the tension of the fish line. A writing .ever (or pen) makes a record of the piling and slackening on a paper tape which moves along at the rate of about, three-quarters of an inch a minute. From the marks made Dr. Laird can tell exactly just when you moved m your sleep and how much. , It turns out from scores ol reeoruS that the average sleeper moves about ten times an hour. One hoy who slept in Dr. Laird’s laboratory moved more than 150 times some nights, althouga the total actual time spent in twisting and squirming was less than five mm'ltAbout half of the subjects thus far studied did most of their moving dining the first hour or two and therefore belong to the diminuendo type. Gt course the recorder is not started unto Dr. Laird is reasonably sure that sleep has actually begun. Slight noises do not explain this diminuendo sleeping. Two subiects may sleep in the same | room and still show different curves i From the studies thus tar made it looks as if crescendo sleeping is the more typical. Six of Dr. Laird s subjects were normally crescendos. He studied their sleep after they had eate.l dill pickles, baked beans and cabbage ; salad and at other, times alter ; they . had eaten a light cereal. They remainled crescendos after cereal but became ; I diminuendos after the heavier meals. In • cidentally the evidence is good that by : eating the right kind of light meal bei fere going to bed sleeping can be im- . proved. >• Do the diminuendos settle down and 11 become less restless than the crescen- , i dos? Not according to the records. HNot only do the diminuendos move i more times during the night than the I others, but. they also move more in the. - last hour.