- Diurnal variation in oculomotor performance - article ; n°1 ; vol.50, pg 201-215

Kleitmann

Description

L'année psychologique - Année 1949 - Volume 50 - Numéro 1 - Pages 201-215
Summary
1. In 18 subjects kept awake for more than 24 hours, on one or more occasions, there was a diurnal variation in oculomotor performance, as judged by the blinking rate, binocular fixation, and lateral oscillations of the eyes.
2. Poorest performance occurred in the early hours of the morning, coinciding with the development of drowsiness.
3. Without intervening sleep, there was a spontaneous recovery of oculomotor performance, along with an increase in alertness, later in the morning or afternoon.
4. An intermediate degree of oculomotor impairment manifested itself in poorer oscillations in post-fixation, as compared to pre-fixation, trials, and in the appearance of diplopia toward the end of the five-minute fixation period.
5. In the execution of lateral sweeps, the templeward moving eye completed its excursion faster than did the nasalward moving eye. This disparity also held in drowsiness, when the sweep was slowed in both eyes.
6. Amphetamine had no effect on oculomotor performance of subjects when the subjects were wide-awake,but ledto improvement of impaired performance observed during drowsiness.
7. Small amounts of alcohol often imitated the impairment of oculomotor performance that occurred in drowsiness.
15 pages
Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.

Informations

• Publié par: L-annee-psychologique
• Publié le: 01 janvier 1949
• Nombre de lectures: 9
• Langue: Français
• Poids de l'ouvrage: 1 Mo

Extrait

N. Kleitmann
J. E. Schreider
X. - Diurnal variation in oculomotor performance
In: L'année psychologique. 1949 vol. 50. pp. 201-215.
Abstract
Summary
1. In 18 subjects kept awake for more than 24 hours, on one or more occasions, there was a diurnal variation in oculomotor
performance, as judged by the blinking rate, binocular fixation, and lateral oscillations of the eyes.
2. Poorest performance occurred in the early hours of the morning, coinciding with the development of drowsiness.
3. Without intervening sleep, there was a spontaneous recovery of oculomotor performance, along with an increase in alertness,
later in the morning or afternoon.
4. An intermediate degree of oculomotor impairment manifested itself in poorer oscillations in post-fixation, as compared to pre-
fixation, trials, and in the appearance of diplopia toward the end of the five-minute fixation period.
5. In the execution of lateral sweeps, the templeward moving eye completed its excursion faster than did the nasalward moving
eye. This disparity also held in drowsiness, when the sweep was slowed in both eyes.
6. Amphetamine had no effect on oculomotor performance of subjects when the subjects were wide-awake,but ledto
improvement of impaired performance observed during drowsiness.
7. Small amounts of alcohol often imitated the impairment of oculomotor performance that occurred in drowsiness.
Citer ce document / Cite this document :
Kleitmann N., Schreider J. E. X. - Diurnal variation in oculomotor performance. In: L'année psychologique. 1949 vol. 50. pp.
201-215.
doi : 10.3406/psy.1949.8443
http://www.persee.fr/web/revues/home/prescript/article/psy_0003-5033_1949_hos_50_1_8443X
DIURNAL VARIATION
IN OCULOMOTOR PERFORMANCE
by Nathaniel Kleitman and Jonas E. Schreider
Department of Physiology, University of Chicago.
Changes in activity and position of the eyes and eyelids have
always been associated with falling asleep and awakening.
Gradual drooping of the upper eyelids and the appearance of
a " " stare are sure signs of drowsiness, and a firm glassy
closure of the eyes usually precedes the onset of sleep. The
overt contraction of the orbicularis palpebrarum muscle occurs
at the time when most of the other striated muscles are relaxing.
During sleep changes in the tonus of the extrinsic eye muscles
lead to an upward and outward deviation of the eyes, indicating
that even the parallelism of the visual axes maintained for far
vision is perhaps an active convergence of the eyes from their
resting positions. This, and the additional effort required to
converge the eyes for near vision and for scanning the visual
field, involves an incessant and varying activity of the oculo
motor apparatus during the entire period of wakefulness, irre
spective of whether the other muscles of the body are overtly
contracting or not. The diplopia observed in very drowsy indi
viduals could thus be ascribed to oculomotor fatigue. The
popular association of double vision with alcoholic intoxication,
rather than with drowsiness, may be due to the fact that at the
usual going-to-bed hour oculomotor coordination is not impaired.
Miles (1) made a quantitative study of oculomotor performance
in drowsiness by photographically recording the movements
of the eyes when their gaze was shifted from one luminous dot
to another, through an arc of 40 degrees, in the horizontal plane. 202 PSYCHO-PHYSIOLOGIE
In the alert state such an oscillation was carried out in about
100 ms (milliseconds), but in extreme drowsiness the movement
required from 160 to 250 ms, and the sweep was often broken
up into several saccadic jerks. Drowsiness also led to poorer
fixation of the dots at the termination of the sweep, and the
usual corrective adjustments were either omitted, or grossly
exaggerated.
In numerous studies on the effects of prolonged sleep depri
vation we noted a diurnal variation in the degree of drowsiness
overtaking our subjects (2). Extreme, almost overpowering
attacks of sleepiness usually occurred between 3 and 6 a. m.,
but later in the forenoon, and especially in the afternoon, the
subjects were much more alert. In the course of the succeeding
night, however, drowsiness appeared again and became progres
sively worse toward the critical early morning hours. While the
behavioral deterioration from loss of sleep was proportional to
the total duration of experimental insomnia, the waxing and
waning of drowsiness made it easier to keep the subjects awake
in the afternoon of third day than in the middle of the second
night. The purpose of this study was to find out if the diurnal
variation in alertness was associated with a parallel variation
in oculomotor performance.
Subjects, procedures, and methods. — Our observations were
made on 13 men and five women, most of them students in
their early twenties, all in good health at the time they were
kept awake for about 30 hours. Ten of these, six men and four
women, were studied only once, but the remaining subjects
went through two or more periods of sleep deprivation. Usually
four or five subjects were tested at one time, and our analysis
is based on 13 experiments and a total of 50 subject-nights.
The observations were made during the winter and spring, and
the subjects were indoors most of the time. They were not
permitted to lie down, nor to sit with their eyes closed, but
were not regimented otherwise with respect to activity.
The experimental procedure consisted of preliminary testing,
at irregular intervals, during the first day and evening, and
continuous surveillance and regularly spaced (every 2-3 hours)
testing during the night and the following forenoon, sometimes
also afternoon. When several individuals were studied simul
taneously, they were encouraged to engage in group activities,
such as conversation and card-playing. They were allowed to
eat, if they became hungry, but not to consume tea, coffee, or KLEITMAN, J. E. SCHREIDER. ■ OCULOMOTOR PERFORMANCE 203 N.
alcoholic beverages. In some cases body temperatures were taken
at two-hourly intervals throughout the period of observation.
Prior to each test, the subject was asked routinely to give
an estimate of his degree of alertness, and this was supplemented
by an objective description of his condition, furnished by the
test administrator. The quantitative evaluation of oculomotor
performance was based mainly on photographic records obtained
by means of a modified model of an Ophthalmograph, a portable
binocular eye-movement camera, manufactured by the American
Optical Company and designed to furnish information on the
characteristics and maturity of reading in school children (3).
The subjects is comfortably seated, with chin resting on a
adjustable support and forehead leaning lightly against a fixed
barrier, so that the position of the head with respect to the
camera is kept constant. Beams of light from two laterally
located lamps are reflected by the corresponding corneas into
adjustable telescope tubes that focus them as two tiny dots on
moving 35-mm photographic paper or film. As we used the
instrument, the subject was asked to look at a target card,
placed in a holder 33 cm away from the eyes, with a centrally cross and a 2-mm dot at each side edge. The distance
between the two dots was 13 cm, and, in shifting his gaze from
one dot to the other, the subject had to rotate his eyes through
an arc of 22.5 degrees. Records could be obtained of the position
of the eyes when the subject looked fixedly at the central cross
and of eye-motility, as the subject executed alternate sweeps
in looking at the dots.
In standard operation of the Ophthalmograph, only film is
used, and it is run by a synchronous motor at the rate of 13 mm
per second. We were able to reduce this speed ten times by
manually operating a crank attached to the feed-spindle. Fair
constancy of speed was obtained by turning the crank-handle
in synchrony with the second hand of an electric clock watched
by the operator. Another modification of the apparatus involved
the introduction of frosted glass screens in front of the lamps,
to be used when the speed of the film was reduced. In addition,
in some tests an electric timer was placed near the left-side
lamp. The revolving sectors of the timer interrupted the beam
of light reflected from the left cornea ten times per second, and
it was used as a check on the rate of movement of the film.
The oculomotor performance test involved continuous gazing
at the central cross for five minutes, preceded and followed by PSYCHO-PHYSIOLOGIE 204
a variable number of sweeps from one dot to the other, at a
rate of 70 per minute, timed by metronome clicks. During the
period of fixation, the operator counted and recorded the numb
er of blinking movements, as well as slower eyelid droopings,.
that occurred in each of the five minutes of observation. In the
early experiments we recorded either fixations, using Insurance
Bromide paper, or sweeps, on Panatomic-X film, but later we
were able to get both in the same test, by dimming the lamps
and greatly slowing the speed during the five minutes of fixation, using film throughout. The dimmed l