and maintain a good night vision, has for a
long time stimulated research towards improv-
ing it.

Studies on the value of the morphoscopic
night vision threshold, that is to say on the
perception of shapes under reduced conditions
of illumination, which seems to constitute the
best standard for testing the practical value of
an aviator’s night vision, have revealed that this
threshold improves with the number of night
flight hours.

It was therefore logical to try to simulate the
conditions of night flight in order to obtain
such an improvement of night vision as a great
number of night flight hours achieves, similarly
to pilot training accomplished on the ground
with a Link-Trainer.

The Rose and Flack device, modified and
improved by Perdriel, has been used syste-
matically for this purpose, according to a tech-
nique making it possible to achieve the suc-
cessive stages of mesopic and scotopic vision
and to demonstrate the possibilities as well as
the limitations of night vision, and the means
to avoid them.

An improvement by 18 per cent of the value
of the morphoscopic vision threshold after
eight training sessions has established the ef-
ficiency of this technique which permits check-
ing, maintaining and recovering a satisfactory
night vision without resorting to the expensive
and sometimes dangerous method of frequent
night flights. (Translated summary. )

Mercier, A., and Perdriel, G. Les problémes
visuels dans le vol a basse altitude. (The
problem of vision in flight at low altitudes. )
In Mercier, A. (Ed.), Visual Problems in
Aviation Medicine, N. Y.: Pergamon Press,
1962, pp. 78-83.

Flying at low altitude and high speed re-
quires an increased attention which produces
a nervous tension. Turbulences and accelera-
tions in the proximity of the ground may be
factors of vision impairment.

Increased speeds and reduced altitudes make
the detection of ground targets more difficult
because visual acuity depends essentially upon
the sensory-psycho-motor chronology. Meteor-

ological conditions, the nature of the region
flown over and the time of the flight have an
effect upon the detection of targets. Training
can improve flying under these conditions.

Variations in lighting inside and outside the
cockpit also affect vision. At low altitudes, the
detection of another aircraft becomes more
difficult. Heat, vibration, twilight or night fly-
ing are also the causes of visual disturbances.
(Translated summary. )

Mercier, A., and Perdriel, G. Les problemes
opthalmologiques posés par Tutilisation des
helicoptéeres et des appareils a decollage et
atterrissage vértigaux. (Opthalmological
problems posed by the use of helicopters
and vertical take-off and landing planes.)
In Mercier, A. (Ed.), Visual Problems in
Aviation Medicine, N. Y.: Pergamon Press,
1962, pp. 89-94.

Helicopter pilots must have a perfect stereo-
scopic sense because they must be able to de-
termine vertically the altitude, relief, and slope
of the ground. Therefore, the correction of re-
fractive defects, mainly myopia and myopic
astigmatism, is necessary.

Piloting a helicopter requires a constant vis-
ual effort, more sustained than on any other
kind of aircraft.

During certain missions, atmospheric turbu-
lences at low altitude increase visual fatigue;
sound vibrations have a similar effect.

The stroboscopic effect of the rotor blades
has been responsible for some cases of photo-
genic epilepsy. Predisposition to this condition
must be detected by means of an EEG with
make-and-break photic stimulation.

Great accelerations in the speed at which the
objects seem to pass by, and hovering flights
at higher altitudes sometimes cause a feeling
of vertigo.

Atmospheric conditions sometimes render the
evaluation of distances difficult.

Take-off and landing of VTOL aircraft may
raise a dense cloud of dust which impairs the
outside visibility during the most critical time.

Protection of the pilot’s eyes is also consid-
ered in relation to the required missions.
(Translated summary. )

-12~


tions (constant light, constant darkness). The
inborn endogenic component prescribes a cer-
tain form of periodicity (bigeminal pulse),
which cannot be changed from without at will
and which also limits the possibility of a pass-
ive frequency modulation.

The phase relation of the animal 24-hour
cycle is determined exclusively by known en-
vironmental stimuli — the physical-chemical
and sociological time indicators. Through ap-
propriate manipulation of these time indicators
any desired phase delay can be produced. With
a sudden delay of the time indicator by 180°
(inversion experiment) the animal phase fol-
lows slowly; complete synchronization is
reached on the average after eight days. If the
known time indicators are excluded, the fre-
quency of the animal periodicity changes. The
assumption of an unknown earthly or “cosmic”
factor which links the phase to the local time
is unfounded.

Man does not react basically differently from
animals to physical - chemical environmental
forces. If in spite of this the inversion of his
cycle in the experiment is not at all or only
incompletely achieved, it has the following
causes: 1. The reversal of the time indicator
is more or less incomplete. 2. The importance
of the sociological-psychological time indicators
is not recognized; they can only with consid-
erable effort be excluded or reversed. 3. The
knowledge of the true time of day suffices to
make inversion difficult even with quite com-
plete fulfillment of condition 1. Points 2 and
3, which are based on processes of conscious-
ness, are the cause of the fact that man in con-
trast to all animals appears in particular meas-
ure to be bound to local time. The assumption
of an unknown control factor is not necessary
for the explanation of this peculiarity. If in the
future still more entities should be discovered
in addition. to the more than 40 known diurnal
periodic meterological factors, they would
merely as additional time indicators join the
others, of which the light-darkness alternation
has by far the greatest importance. (Translated
summary. )

Aschoff, Jurgen. Aktivitatsperiodik bei Gim-
peln unter natiurlichen und kunstlichen Be-

lichtungsverhaltnissen. (Periodic cycle of

activity in bullfinches under natural and ar-

tificial conditions of illumination.) Zeitschrift

fur vergleichende Physiologie, 1953, 35, 159-

166.

1. The 24-hour periodicity of activity of di-
urnally active birds (bullfinch) with a main
maximum in the morning and a smaller maxi-
mum in the evening can be observed also dur-
ing artificial change of illumination with abrupt
turning on and off of light. When the light
phase of the artificial day is kept short in pro-
portion to the natural conditions, the evening
restlessness is suppressed: —

2. The periodicity of activity remains un-
changed under completely constant environ-
mental conditions — as long as they are bear-
able for the birds. The changes of frequency
which are observed are opposite those found
in nocturnally active animals. Continuous il-
lumination causes from the first day on a short-
ening of the duration of periodicity (e.g., 22
instead of 24 hours); during continuous dark-
ness the time at which restlessness sets in is
later every day by an approximately equal
amount. (Translated summary. )

Aschoff, Jurgen. Zeitgeber der tierischen Ta-
gesperiodik. (Time signals in the daily pe-
riodic cycle of animals.) Die Naturwissen-
schaften, 1954, 41, 49-56.

The frequency consistency of all daily peri-
odic biological processes and the absence of a
statistical distribution of the phases throughout
the day presumes synchronization. The syn-
chronizing factors are called time signals. Time
signals for animal 24-hour periodicity are all
those periodic environmental processes of a
continuous or discontinuous nature, coupled to
earth’s rotation, which have a stimulating ef-
fect on animals.

Time signal properties are not confined to
meteorological elements, but may also be part
of the animated environment of the animal
(ecological, sociological periodic events.)
Under natural conditions several time signals
are active simultaneously of which mostly one
determines the predominating phase of the ani-
mal periodicity; however, a conflict among dif-
ferent time signals may occur.

~3-



position of the sun (midnight sun) or on sun-
rise or sunset.

5. The same periodicity can be established in
the life processes of plants.

6. In addition to this periodicity of animals
and plants, there is a periodicity of the electri-

cal conductivity of air, which is likewise de-
pendent on the time of day and the local time;
it is however not the sole cause for the rhythm
of living things (see our monograph); instead,
all three of these periodicities are subject to a
cosmic principle which is as yet unknown.
(Translated summary. )

—~16—


an increase in the rest activity observed prior
to the rotation; in the case of contralateral ac-
celeration, the rest activity decreased. With re-
tardation excitation, a decrease in the rest ac-
tivity occurred for homolateral rotation, and an
increase in the rest activity was observed with
contralateral rotation (type I).

Approximately % of the neurons showed an
increase in activity with homolateral, as well
as with contralateral acceleration, and with re-
tardation, a decrease in the impulse frequency
was observed (type II).

In one experiment, a distinct short-lived ac-
tivity inhibition was observed with accelera-
tions toward both sides; with retardation, the
impulses returned (type III).

The response types found in the vestibular
nerve are also observed in the vestibular centers.

2. In a comparison of the short rotatory
excitation consisting of acceleration and retar-
dation, of the occurring frequency. fluctuations
in the electrical activity, and of the cupula
movements to be expected from Steinhausen’s
cupula theory, an activating effect was assigned
to the utriculopetal displacement of the cupula
in the horizontal semicircular canal, and a re-
tardation effect was assigned to the utriculo-
fugal displacement in case of the type I re-
sponse. The activity changes at the end of
rotations, which so far have been called “after-
effects”, were therefore not considered to be
postexcitatoric phenomena, but they were con-
sidered to be direct reactions to certain cupula
displacements.

3. The postrotatory course of the excitations
exhibited a rhythmic zig-zag pattern in which
short, steeper and longer, more level parts of
the curve could be distinguished. The dura-
tion of such an upward and downward move-
ment amounts to little more than one second.
The significance of this observation has been
discussed.

4. The different activity states of the left
and right vestibular center during the same
rotatory excitation were studied: immediately
after termination of the long rotation, a change
in activity could be detected by simultaneous
derivation from both vestibular centers: when

the activity of one side of a nucleus was en-
hanced in the first postrotatory phase, a dis-
tinct decrease in activity occurred in a second
postrotatory phase, whereas a nucleus which
was inhibited in its activity during the first
postrotatory phase, underwent a distinct in-
crease in discharge frequency in the second
postrotatory phase. This reversal in the ac-
tivity has been related to peripherous processes.

5. The position of the electrode tip, which
had been marked by the iron reaction, was ac-
curately determined by histological studies,
and the relation to the vestibular centers was
established. It was found that vestibular ro-
tatory responses (in the horizontal plane) of
typés I and II can be found in the nucleus
triangularis, as well as in nucleus Deiters. The
position for response type III could not be
determined.

6. The combination of the electrophysio-
logical experiments with histological checking
of the grounding site has been found to be
a suitable method for additional research on
the physiological functioning of the individual
vestibular centers. (Translated summary.)

Evrard, E. L’emploi du test de Bourdon-
Wiersma dans la sélection des aviateurs.
(Use of the Bourdon-Wiersma test in the se-
lection of pilots.) Revue de Médecine Aéro-
nautique, 1962, 1, 42-44.

Results of an experiment attempting to eval-
uate the Bourdon-Wiersma test for detection
of latent epilepsy and fluctuation in the level
of consciousness are presented. The experi-
mental group consisted of 651 pilot candidates
of the Belgian Air Force.

As regards the predictive value of the test
in the selection of pilots, the author concludes
that the test is of limited worth, as it does not
provide a clear-enough differentiation concern-
ing prediction of success in training to allow
for its substitution for a battery of tests, but
merely for its incorporation into such a battery.

As a diagnostic tool in the psychological ex-
amination of pilot candidates, however, it is
concluded that the test provides valuable in-
formation, as it undeniably contributes to the
detection of epileptics and hysterics.

~8—


II. Muscular activity increases body tem-
perature rapidly. The temperature rise contin-
ues as long as work continues. Work of the
same intensity causes the same rise in tempera-
ture. The end of work is soon followed by a
marked, long-lasting drop in temperature.

During the nights following hard muscular
work the temperature was lower than during
nights after a day of rest.

IV. The main effect of fasting consists in
decreasing the extent of the fluctuations of the
curve. Fasting after hard work caused a low-
ering of the daily fluctuation to about 0.6° C,
with long periods of almost constant tempera-
ture. The average temperature of a day of
fasting after a rest period was not noticeably
different from the normal daily temperature.
On days of fasting after hard work the average
level of the temperature was lower by almost
°c.

V. After ten successive days during which
work was performed at night and sleep and
rest were taken in the daytime no tendency for
an inversion of the temperature curve could be
observed.

Note of Translator: The basis for the temper-
ature degrees referred to in this paper was al-
ways melting sodium sulfate (see Pfliiger’s
Archiv, vol. 88, p. 497); however, the tempera-
ture of 32.484° C stated therein refers to a mer-
cury thermometer and not the international
hydrogen thermometer; when using the latter
we ought to substitute for the above figure
that of 32.379° C. When this is done here, all
figures in the present paper are 0.1° C too high.
Since all thermometers used today are based on
hydrogen it follows that in clinical use etc. all
data presented here must be reduced by 0.1° C.
(Translated summary. )
ter Braak, J. W. G. Untersuchungen ueber

Optokinetischen Nystagmus. (Research on

optokinetic nystagmus.) Archives Néerlan-

daises de Physiologie de Homme et des Ani-

maux, 1936, 21, 309-375,

Two types of optokinetic nystagmus are to
be distinguished from each other: “stare” nys-
tagmus and “look” nystagmus.

A. “Stare” nystagmus is characterized by
the fact that its occurrence is entirely deter-

mined by the physical-optical conditions in the
field of vision.

The excitatory stimulus is the displacement
of retinal images. Stare-nystagmus is exclus-
ively conditioned by this displacement; other
factors (e.g. attention) are not necessary for
its excitation.

Stare-nystagmus has been observed by us
in man and also in monkeys, dogs, cats, and
rabbits. The mechanism of stare-nystagmus is
simplest to study in the rabbit. Observations
on that animal have shown the following:

I. Stare-nystagmus is excited only when all
or at least the majority of the contrasts situ-
ated in the field of vision move in the same
direction.

II. Stationary objects (contrasts) in the
field of vision prevent its excitation, for the
reason that their images move in the opposite
direction as soon as the eyes follow the mov-
ing objects and thus constitute an opposite
stimulus.

III. If there are no stationary contrasts (e.g.
in the dark) the motion of a single point of
light in the field of vision suffices for excitation
of nystagmus (both the slow and the fast phase).

IV. It is immaterial what part of the retina
is stimulated by the various retinal images.

v. A shift of the retinal images that con-
ditions an increase in excitation in the recep-
tors of the retina (e.g. when a white stripe on
a black ground broadens on one side) consti-
tutes a strong stimulus, a shift which occasions
decrease in excitation (e.g. when a white stripe
on a black ground narrows on one side) a weak
stimulus. .

VI. Shift of the retinal images toward the
temple (ie. in the rabbit to the rear) consti-
tutes a strong stimulus, shift toward the nose
a weak stimulus.

VII. If one eye is fixed immovably with
clamps and a shift of contrasts takes place in
the field of vision of this eye, nystagmus of the
other eye is induced, provided no stationary
contrasts are present in the field of vision of
that eye, e.g. when it is blindfolded.

VIII. Stationary contrasts in the field of
vision of the immobilized eye in that case exert

-5-



The coordination of a periodicity with the
time signal is not always equally consistent.
Changes in stimulus sensitivity of the animal
leave room for substantial changes in the mat-
ing effect. Variations in the animal daily pe-
riodicity with regard to periodic form and
phase situation can in part be explained in this
manner.

For all daily periodic biological processes
with endogenic components, the time signal is
only conditionally of a determinant nature.
Phase shifts of the time signals follow biological
periodicity without any difficulty; frequency
modulation is subject to relatively narrow limits.

Knowledge of time signals and their effect
is the necessary prerequisite for good results in
the investigation of 24-hour periodicity. (Trans-
lated summary. )

Aschoff, J., and Wever, R. Resynchronisation
der Tagesperiodik von Vogeln nach Phasen-
sprung des Zeitgebers. (Resynchronization
of the daily cycle in birds after a phase
shift in the time signal.) Zeitschrift fiir ver-
gleichende Physiologie, 1963, 46, 321-335.

The periodic jump activity of finches (Frin-
gilla coelebs L.) is easily synchronized with an
artificial illumination - darkness change of a
12-hour illumination period (250 lux) and a 12-
hour dark period (0.5 lux), which acts as time
signal. The activity of the birds begins at the
time “light on” or for varying time periods
prior to this time (= more or less strongly neg-
ative phase angle difference). After a phase
shift of the time signal by a single shortening
or lengthening of the illumination period or the
dark period, several periods are usually re-
quired until the bird has restored its original
phase position relative to the time signal. Dur-
ing this resynchronization, the overall activity
in each period is decreased.

Phase shifts of 6 hours in the time signal are
compensated by the bird at varying rates de-
pending on the direction of the shifts: for a
single lengthening of an illumination period, or
a dark period, by 6 hours, resynchronization
takes 4-5 days; for a corresponding shortening
of the time signal period, resynchronization
takes only half as long.

The rate at which the bird displaces its phase
after a phase shift in the time signal depends
also on the original phase angle difference: a
bird with a strongly negative phase angle dif-
ference adjusts more slowly to a phase shift by
+6 hours than a bird with a phase angle dif-
ference of zero. These results are also expected
theoretically because the phase angle differ-
ence is a measure of the characteristic fre-
quency of the system; a more negative phase
angle difference corresponds to a higher char-
acteristic frequency.

After a 12-hour phase shift, by doubling of
an illumination period or of a dark period, the
finches behave similarly as in the case of a
+6-hour phase shift. They displace the phase
in both cases by several extensions of the pe-
riod. Individual cases for which after a dou-
bled illumination period two very short periods
seem to arise at first, may be explained, under
consideration of masking effects of the illumi-
nation on the activity, in the same way as the
uniform results of the experiments involving a
doubling of the dark period.

In agreement with data of other authors, the
mean rate of the phase displacement after a re-
tarding phase shift amounts to 1.0-2.0 hour/day.
The phase is displaced at twice this rate after
a phase shift involving shortening of the time
signal period. (Translated summary. )

Benedict, F. G., and Snell, J. F. Korpertem-
peratur-Schwankungen mit besonderer
Rucksicht auf den Einfluss, welchen die Um-
kehrung der taglichen Lebensgewohnheit
beim Menschen ausubt. (Fluctuations in
body temperature with particular regard to
the effect which inversion in daily routine
has for human beings.) Pfliigers Archiv fiir
die gesamte Physiologie, 1902, 90, 33-72.

I. The normal curves of the different indi-

viduals tested show the ordinary rhythm of the
temperature curves.

II. The curve for the axillary temperature
on the whole is parallel to that of rectal tem-
perature; however, deviations of between —0.06
and +0.38°C were found between the rectal
and the axillary temperature.

~4—




Under physiological conditions (rotation of the
animal with eyes open) there is neither opto-
kinetic post-nystagmus nor labyrinthine rota-
tion nystagmus.

B. In rabbits, dogs, and monkeys, stare-
nystagmus can still be excited after complete
extirpation of the cerebrum; it is therefore a
subcortical reflex.

After one-sided cerebrum. extirpation the
“stare” nystagmus in the dog becomes perma-
nently asymmetrical, while in the rabbit and
in the monkey no lasting differences in com-
parison to the intact animal have been proved.

C. “Look” nystagmus occurs only when ob-
jects that catch the attention move within the
field of vision. These objects need only con-
stitute a quite small part of the total contrasts
of the field of vision; this nystagmus is not sup-
pressed by stationary contrasts.

The slow phase of “look” nystagmus is iden-
tical with a “following movement;” the fast
phase on the other hand is not identical with a
“focusing movement.” Although in “look” nys-
tagmus the tendency exists to reflect “pre-
ferred” objects on the fovea, the periphery of
the retina is not without significance in its
excitation.

Apart from man, where it is best studied,
“look” nystagmus is found in dogs and mon-
keys. On the other hand it is always lacking
in the rabbit.

No indication is found of a central “inertia”
(post-nystagmus, etc. ).

D. After extirpation of the cerebrum, “look”
nystagmus is permanently lacking in the mon-
key and in the dog, as also after extirpation of
the two centers of vision (area striata). On
the other hand it is retained (in the dog) after
extirpation of the sensorimotor cortex. “Look”
nystagmus is thus a cortical reflex which comes
about by way of the visual cortex. (Trans-
lated summary.)

Bugard, P., and Henry, M. Quelques aspects
de la fatigue Vaviation de transport. (Some
aspects of fatigue in aviation transportation. )
La Presse Médicale, 1961, 69, 1903-1906.

The findings are summarized in the following
manner: Humoral manifestations were ob-

served in the crews of the jets and especially in
the plane captains. Hyperaldosternism due to
heat (there is a miniature tropical climate in
the plane), through emotional tension (pilot-
ing), through muscular fatigue (commercial
personnel). A drop in the 17-CS in the men
(because of fatigue), with a slight rise during
rest (irregularity of the basic rythm due to the
upsetting of the physiological timing as a result
of too rapid passage through different time
zones). Slight rise in the 17-CS in the hostesses
remaining in service for too long an interval
and who manifest, in this traveling occupation,
a “kind of rejection of their femininity.” Rise
in the 17-OH of both sexes, but also in the
creatinine, as the jet flight requires the suprare-
nal cortex to be in an “aroused state” that gen-
erates a feeling of alarm, as opposed to the
“cruising state” of conventional aircraft. Lastly,
the elevation of the chronaxies before the jet
flight shows that the crew is poorly rested from
the previous flight. Of course, a satisfactory
physical state is a primary condition for safety.
(Translated abstract. )

Eckel, Walter. Elektrophysiologische und his-
tologische Untersuchungen im Vestibularis-
kerngebiet bei Drehreizen. (Electrophysio-
logical and histological studies of rotatory
excitation in the nuclear region in the vesti-
bule of the ear.) Archiv fiir Ohren-, Nasen-,
und Kehlkopfheilkunde und Zentralblatt fir
Hals-, Nasen-, und Ohrenheilkunde sowie
deren Grenzgebiete, 1954, 164, 487-513.

After exposure of the medula oblongata in
the rabbit, the excitation effect of horizontal
short and long rotations on the individual neu-
rons of the vestibular centers was recorded by
means of microelectrodes, and the localization
of the investigated brain sites was histologi-
cally determined by means of iron coloration.
The following results were obtained:

1. As was the casé in Gernandt’s vestibular
nerve groundings, three different types of re-
sponses to short rotations (rotations by approx-
imately % of the circumference within one to
two seconds) arose:

Approximately % of the recorded neurons
reacted toward homolateral acceleration with

-7-



AM-65-17

Aviation Medicine Translations:
ANNOTATED BIBLIOGRAPHY OF RECENTLY
TRANSLATED MATERIAL. III.

Mary Ellen Allen
William E. Collins, Ph.D.
Jerry V. Tobias, Ph.D.
Ruth Ann Crain

Approved by Released by

Stemnbey  Menerhben Y db Wale

Srantey R. Mouter, M.D. M. S. Warrz, M.D.
Dmector, CARI Feperat Ain SURGEON

APRIL 1965

FEDERAL AVIATION AGENCY

Office of Aviation Medicine
Civil Aeromedical Research Institute
Oklahoma City, Oklahoma



2. On the other hand spontaneous turning
occurring in diffuse light and in the dark or
caused by application of shadows is arhythmi-
eal. Turnings in both directions occur with
equal frequency throughout the day. (English
summary. )

Grandjean, E., Abelin, T., and Rhiner, A. Eine
Apparatur zur Messung der Gleichgewichts-
bewegungen. (A new apparatus for the
quantitative measurement of equilibrium
movements.) Schweizerische Medizinische
Wochenschrift, 1963, No. 33, 1028-1030.

A new apparatus for the quantitative meas-
urement of equilibrium movements in the
standing subject is described. The body move-
ments are transmitted to a plate with contact
points in high density, and the number of con-
tacts is recorded by an electronic counter.

An initial series of experiments in 27 subjects
was conducted to determine the range of vari-
ation of the measurements under nonstandard-
ized conditions. (Translated summary.)

Kappey, F., and Albers, C. Der Einfluss der
relativen Feuchte auf die Auslosung des
Hechelns beim wachen Hund. (Influence
of relative humidity on tachypnea in the
dog.) Pfliigers Archives, 1963, 278, 262-272.

1. The influence of gradual increase and
decrease of ambient temperature, at three dif-
ferent values for relative humidity, on body
temperature and respiratory rate was investi-
gated by the authors in 5 non - anesthesized
dogs.

2. At the same ambient temperature, the
respiratory rate rose proportionately to relative
humidity. Body temperatures were also higher
at a high relative humidity than at low relative
humidity.

3. During the return of temperature to nor-
mal, the respiratory rate remained at a high
level longer than the skin temperature and the
brain temperature. The relations between rec-
tal temperature and respiratory rate did not
differ significantly during temperature increase
or decrease as well as at all three degrees of
humidity.

4. The findings justify the assumption that
the temperature of the mucosa in the upper
respiratory tract participates in triggering tach-
hypnea. The authors discuss the factors by
which the temperature of the mucosa can be
influenced. (Translated summary.)

Kappey, F., Thiele, P., and Albers, C. Der Ein-
fluss der Warmetachypnoe des Hundes auf
die alveolar-arterielle 0,.-Spannungsdifferenz
(AaD). (Influence on thermotachypnea in
the dog on alveolar-arterial oxygen tension
differential [AaD].) Pfliigers Archives, 1963,
278, 251-261.

1. Alveolar-arterial ,-tension differential
was tested during three stages of oxygen intake
on 12 dogs with weights from 17 to 31 kg under
chloralose narcosis during normal respiration
and during thermotachypnea.

2. When breathing air, the normal alveolar-
arterial differential (respiratory rate 15/min)
amounted to 8.1 Torr and during tachypnea
(respiratory rate 170/min) 5.6 Torr. The dif-
ference was not significant.

3. Under hyperoxia (alveolar 0,-pressure
233 Torr), the normal alveolar-arterial differ-
ential (respiratory rate 15/min) amounted to
43.0 Torr and during tachypnea (respiratory
rate 146/min) 39.7 Torr. From this was calcu-
lated a short-circuit blood flow of 2.0 and/or
1.3% of the cardiac volume per minute. This
difference was not significant.

4. Under hypoxia (alveolar 0,-pressure 45
and/or 52 Torr), the normal alveolar-arterial
differential (respiratory rate 31/min) amounted
to 1.7 Torr and during tachypnea (respiratory
rate 138/min) 3.7 Torr. From this was calcu-
lated an 0,-diffusion factor of 1.32 and/or 1.22
ml minTM Torr’ kg”. This difference was not
significant.

5. The authors concluded from the findings
that thermotachypnea does not reinforce the
functional inhomogeneities of the lung. (Trans-
lated summary. )

Lavernhe, J., Lafontaine, E., and Laplane, R.
Le transport aérien supersonique: Aspects
médico - physiologiques. (Supersonic air

-—10-—


A review of other evaluative studies of the
Bourdon-Wiersma test is also presented.

Fischer, H. Beitrag zur Frage der Fettembolie
bei tédlicher Druckfallkrankheit. (Contri-
bution to the question of fat embolism in
fatal decompression sickness.) Monatsschrift
fiir Unfallheitkunde und Versicherungs-
Medizin, 1963, 66, 318-322.

An examination of the role of fat and gas
embolism in decompression sickness was un-
dertaken through the study of several fatalities
occurring in the German Luftwaffe. Anatomi-
copathological findings are reported, and sev-
eral hypotheses are advanced; however, results
of the study provide no conclusive answer to
the question under investigation.

Geisler, Marianne. Untersuchungen zur Tages-
periodik des Mistkafers Geotrupes silvaticus
Panz. (Studies of the diurnal periodicity of
the dung beetle geotrupes silvaticus Panz.)
Zeitschrift fur Tierpsychologie, 1961, 18, 389-
420.

J. Periopicrry or ACTIVITY

1. Under the conditions of a natural change
of day and night and an artificial 12/12 hour
day the diurnal rhythmical activity of the
mainly day-active dung beetle Geotrupes silva-
ticus Panz. is diphasic and has two maxima of
activity, one in the morning and one in the
evening. This periodicity of activity is subject
to seasonal influences; the morning maximum
depends on the time of sunrise, whereas the
time of evening activity seems to be fixed.

2. The rhythm of activity is mainly endo-
genous. It adjusts only after some delay to a
sudden change in the rhythm of light and
darkness, or to a 12-hour shift in the light and
dark phases; adjustment takes about a fort-
night. Under constant lighting conditions (per-
manent light or darkness) the periodicity is
maintained for weeks, but shows only one max-
imum of activity per day. In constant darkness
a period of 24 hours is maintained, but in con-
stant light of 15 1x the rhythm period is 24.7
hours.

Il. RyramicaL OpmenraTion IN POLARIZED
Licut

1. In natural polarized light the dung bee-
tle controls its courses with the right eye before
and the left eye after noon. The preference
angles of 0°, 45°, and 90° respectively to the
position of the sun can be used “optionally,” in
the forenoon the beetle increases its angle on
the right side from 0° to 45° to 90°, and in the
afternoon it decreases its angle on the left from
90° to 45° to 0°. The optional use of these
time-dependent preference angles makes east
the preferred direction in the morning and west
in the afternoon.

2. Animals from different biotopes (south-
ern Germany and Sudharz) behaved alike.

3. Animals blindfolded on one side main-
tained courses different from those maintained
by two-eyed animals at the same time of day.

4, In artificial light polarized by a foil the
beetle also adjusts to preference angles of 0°,
45°, and 90° to the direction of oscillation.
These three angles are chosen with a relative
frequency of 2:3:5. There was no relation
between the preference and the time of day;
probably polarized artificial light cannot sub-
stitute for natural daylight.

5. The spontaneous diumal rhythmicity of
menotactic orientation can be interpreted as a
consequence of a link between the taxis mech-
anism and the endogenous periodicity (internal
clock). The rhythmical processes in activity
and in orientation coincide.

6, An attempt is made to establish, in ar-
thropods, a sequence of phyletic development
from single angle-retentiveness of menotaxis to
compass-time orientation.

III. Ruaytxm or Turninc TENDENCIES

1. In orientation in artificial polarized light
and in the odor field the sense of rotation in
the first oriented turning depends on the time
of day. This rhythm may also be adjusted to
an inverted day. In both cases the beetles, in
a normal day, turn more frequently to the left
before and to the right after noon.

-9-



no inhibiting influence, since their images can
no longer move over the retina.

IX. The maximum angular velocity of con-
trasts at which “stare” nystagmus can be ex-
cited is for the rabbit about 70°/sec.

X. No minimum angular velocity for ex-
citation of “stare” nystagmus could be estab-
lished, At an angular velocity of 6’/sec. (i.e.
one revolution of the striped cylinder in 60
hours) a definite nystagmus was observed; at
that velocity the movement of the contrasts is
no longer detected by the human eye.

XI. Experiments on the immobilized eye
showed that movement of the contrasts at 10 to
50’/sec constitute the strongest optokinetic
stimulus.

XII. The slow and the fast phase of nys-
tagmus are excited by the same optical stimu-
lus. Whether the nystagmus begins with a slow
or with a fast phase is primarily dependent on
the original position of the eye. Whether this
phenomenon is conditioned by proprioceptive
impulses of the muscles of the eye or by a
purely central automatic mechanism could not
be established. When the eye is deflected a
rapid phase can also be induced by acoustic
and tactile stimuli:

XIII. The angular velocity of the slow
phase can be used as a quantitative measure of
“stare” nystagmus.

XIV. Study of the quantitative relationships
between the optokinetic stimulus and the nys-
tagmus excited by it has shown that the central
apparatus exhibits an “inertia” and that “equi-
librium” between stimulus and nystagmus sets
in only after some time.

While at first the velocity of the slow phase
gradually increases, it finally attains a constant
value. This constant angular velocity can be
used as a quantitative measure of the strength
of the optokinetic stimulus.

XV. With stimulation of the immobilized
eye, at “optimal” velocity of contrasts (10-50'/
sec.) the velocity of the slow phase is maximal
and several times as great as the velocity of the
contrasts.

XVI. In stimulation of the freely movable
eye the velocity of the slow phase is generally
a little less than that of the contrasts. The shift
of the retinal images is thus compensated for
as far as possible and the reflection of the out-
side world fixed on the retina as far as possible.
This “fixation” of the outside world is achieved
by a “self-regulating mechanism.” The slow
phase cannot be faster in the freely movable
eye, because the stimulus immediately ceases
when the velocity of the ocular movement and
that of the contrasts has become the same.

XVII. At the beginning of a constant op-
tokinetic stimulus the velocity of the slow phase
increases approximately uniformly. Therefore
the acceleration of the slow phase at the be-
ginning of the stimulation can also be used as
a quantitative measure of the optokinetic
stimulus.

XVIII. After cessation of the optokinetic
stimulation nystagmus persists for some time
(optokinetic post - nystagmus). During this
post-nystagmus the velocity of the slow phase
gradually declines (to zero).

The retardation of the slow phase immedi-
ately after cessation of the stimulus can be used
as a quantitative measure of the central
resistance.

XIX. There are close connections between
“stare” nystagmus and labyrinthine rotational
nystagmus. The conditions for excitation of
“stare” nystagmus, under physiological condi-
tions, are usually not created by a movement
of the environment, but by a movement of the
animal, so that there is also stimulation of the
labyrinth.

Probably optokinetic and labyrinthine stim-
uli affect a common center. Labyrinthine stim-
ulus generally produces a much greater accel-
eration of the slow phase than optokinetic
stimulus.

At the beginning of a rotation it is chiefly the
labyrinthine stimulus that sets nystagmus in
motion, while the optokinetic stimulus keeps
nystagmus constant during the continued uni-
form rotation. Upon cessation of rotation laby-
rinthine stimulus is capable of neutralizing the
central excitation set up by central stimulation.

—~6—


Selection pressure favors organisms capable
of adapting their functions to the periodicity of
their surroundings and of taking advantage of
the latter. Primarily this process of adaptation
is elicited by favorable or unfavorable circum-
stantial factors. Adaption becomes fully ef-
fective when the animal has “learned” to pre-
pare for less favorable periods. Baker was the
first to make a distinction between those cir-
cumstantial factors (“ultimate causes”) which
originally release the process of adaptation and
those factors (“proximate causes”) which keep
the adapted organism in conformity with the
periodicity of its surroundings. These “proxi-
mate causes” necessarily must affect the course
of events before the “ultimate causes” do if
adaptation is to take effect advantageously — a
fact which has already been brought to atten-
tion in respect to the yearly periodicity. The
same applies to processes of higher frequency
(for instance daily periodicity) in which the
event to be controlled is not preceded by an
unusually long chain of causes, as it is in the
case of yearly periodicity. The process of adap-
tation “sets” the organism so that it responds
to a “signal” which procures for it a periodical
environment before the occurrence of those
biologically relevant events with which it has to
cope. Thus the causes (“ultimate causes”)
are replaced by time-setters.

For this reason A. L. Thomson 1950 avoided
the term “causes” and defined as follows:
“Ultimate factors . . . which give a survival
value to the adaptation of the bird’s cycle to
that. of the environment . . . proximate (or
“immediate” ) factors which provide that actual
timing that brings the adaptation into play.”

These considerations apply quite generally
to every process of adaptation to periodical
surroundings (see Cullen 1954). It is only in
rare cases that the external factor which origi-
nally caused adaptation, for instance the relation
between hunter and prey, will take over the
function of a time-setter, too. In some cases
a succession of several time-setters may guaran-
tee the controlled series of events. This particu-
larly applies. to the yearly periodicity. It is
quite possible that in the animal’s environment
one time-setter more or less merges into the
next in much the same manner in which, within

the organism, in the anoestrous cycle of organs,
one state of endocrine functions merges into
the next and as one behavior pattern is re-
placed by the following one. In animals breed-
ing in spring the growth of gonads is controlled
by the increasing duration of the daily period
of light, the anoestrous period by the short-
ened day-length of winter. It is hard to de-
cide at what times the endogenous factor and
at what times the time-setter is more effective
in this interaction.

The better the endogenous factor is devel-
oped the greater is its influence, under normal
conditions, on the cause of events and the more,
correspondingly, the time-setter tends to func-
tion as a mere synchronizer (Halberg 1953),
determining the phases without using up much
energy. Under these conditions the time-setter
may be likened to what is called a Steuerfre-
quenz (pilot frequency; the term is given in
German in the English summary) in technical
terms. If the time-setter is altered — in the
sense of a shifting of phases, or a change of
form or of frequency — an interaction develops
between that pair of forces, the endogenous pe-
riodicity and the timegiver; in this case the
behavior of the animal is, within the limits of
its plasticity, the resultant of these two forces.

Time-setters, in the sense of the definition
used in this paper, are always situated outside
the organism. In experiments their effects re-
semble in many ways the phenomenon which
von Holst 1939 termed relative coordination of
central nervous functions. Data, however, do
not suffice to achieve complete comparison.
(English summary. )

Aschoff, Jurgen. Exogene und endogene Kom-
ponente der 24-Stunden-Periodik bei Tier
und Mensch. (Exogenic and endogenic com-
ponents of the 24-hour periodic cycle in
animals and human beings.) Die Naturwis-
senchaften, 1955, 42, 569-575,

The 24-hour cycle in animals and man is
based on an inborn endogenic component which
in the exclusion of all external control factors is
demonstrable as “individual frequency” of a
different cyclical duration. The frequency de-
pends on the kind of animal (diurnal, nocturnal)
and the chosen constant environmental condi-

~2-


Nicolas, M., and Robion, J. Diabete sucre et
personnel navigant. (Sugar diabetes and
navigation personnel.) Reprint of work from
Centre Principal dExpertise Médicale du
Personnel Navigant de UAéronautique de
Paris. 24 pages.

The importance of the methods presently
recommended for the early detection of dis-
orders of glucidic metabolism needs no longer
to be stressed. They are of great value in the
medical examination of civilian and military
flying personnel.

On the basis of 54 observations of diabetics
and prediabetics, collected at the Medical In-
spection Center for Flying Personnel at Paris
from 1959 to 1963, among military and civilian
personnel, the authors examined the means for
improving detection both at the initial medical
examination as well as during the routine
checks. Obesity appears to be the most fre-
quent diabetogenic factor among the foregoing
cases. Systematic utilization of a simplified test
for provoking hyperglycemia is urged during
medical examination of any individual whose
weight exceeds the normal weight by more
than 10%. The same procedure is obviously
recommended whenever a latent diabetes is
suspected (diabetic heredity, staphylococcia,
accumulations of fat).

Subsequently, the authors define the criteria
of medical supervision necessary for certain di-
abetics ‘authorized to continue their activity.
They conclude, after consideration of some
special aspects of the medical and legal prob-
lems involved, by stating that the number of
decisions grounding personnel for diabetes,
closely related to the efficacity of detection,
should become more and more limited in the
future.

Diabetes mellitus continues to be a problem
in overall morbidity because there are still
nearly a million diabetics in France. From
the social point of view, its consequences vary
with age. In the child or the adolescent, its
diagnosis generally involves a corollary prob-
lem of vocational guidance. In the adult, mat-
ters are not as simple as that. Frequently, a
change of activity is necessary and this is the
case all the more when safety plays an import-

ant role in the activity previously exercised.
This latter situation presents itself to a marked
degree in military and civilian flying personnel.
Among the latter, carefully selected during the
initial medical examination, a genuine diabetes
mellitus is discovered not infrequently during
later routine medical checks. In such cases,
regulations force the examiner to ground the
individual. Depending on the degree of the
disorder, on the competence, on the function
aboard the plane, and on the seniority of the
individual in his activity, an exception to the
rule is sometimes suggested. Based on the
above elements, a more or less retricted per-
mission to continue in flying service is not too
infrequently issued by the last instance, the
Commission for Approval of Flying Status in
the case of military personnel, or the Medical
Council of Civil Aviation in the case of civilian
flying personnel. However, this always pre-
sents numerous difficulties.

Now that prophylaxis of diabetes is possible,
now that early detection makes treatment
possible at the reversible stage, and now that
the cure of certain types of diabetes seems
possible, it may be pertinent to review the
methods of detection and medical expertise
presently being practiced in medical examina-
tion centers for flying personnel.

This is the purpose of this report which
would not have been possible without access to
the files of the Medical Expertise Center for
Flying Personnel at Paris (CPEMPN).

A succinct analysis of the information ap-
pears to suggest a new concept of expertise
and further highlights some particular aspects
of the medico-legal problems. (Translated
summary. )

Popovic, M., Milovanovic, D., and Volf, N.
and Psychologists Dragioevic, C. Vlajnic M.,
and Berger J. HEKM ACHEKTH HEYPO3A KoA
paAtoreArl pa®ticra It KonTeoAoPA AETEHA
(Some aspects of neuroses among wireless
and flight control operators.) Medicinski
Glasnik, 1963, 17, 193-198.

A working team composed of neuropsychi-
atrists, psychologists, and social workers ex-
amined 95 wireless and flight control operators

~123—



B. Pigeons were trained to a compass direc-
tion within a certain circumscribed period (20
to 40 min. each day). Most of them main-
tained a constant angle to the sun when they
were tested outside the training time. Only
one of 7 pigeons failed to orient to the actual
position of the sun, but rather to the compass
direction derived from it. If the training times
are spread throughout the day, all pigeons
allow for the sun’s motion and choose the right
compass direction.

Under constant illumination the endogenous
rhythm used for the sun-azimuth compass runs
autonomously. ‘Nevertheless, if the phase of
the light-dark alternation is shifted by six hours,
coincidence of the internal rhythm’ with the
artificial day-night alternation is attained with-
in 3-4 days. Shifting back to the original phase
requires 2-3 days under artificial light; under
the conditions of the natural day (in an aviary)
less time is necessary.

Overcast sky does not prevent pigeons from
choosing the training direction, but they show
less accuracy than under a clear sky. They are
able to locate the sun even when the human
eye fails to do so. During the night pigeons
do not allow for solar movement.

C. Pigeons subjected to the shifting procedure
were released at distances varying from 100 to
5.5 miles. The distribution of the observed
departures is wider in the shifted birds than in
the controls. Shifting 6 hours in advance gave
an average deviation of 66° to the left regardless
of the direction of displacement. The deviation
of the experimental group remains constant in
relation to the bearing of the control pigeons
for each release point. Direction of departure
(in relation to the true home direction) and
success of homing are positively correlated.
Shifted pigeons tend to be reported from those
directions in which they departed. An average
deviation of 85° to the left (in relation to the
median direction of departures of the controls)
was found.

Many shifted pigeons must define their final
course within a range of not more than 1.2
miles from the release point, others correct
later on the way.

Under moderate overcast the homing ca-
pability remains effective; shifted pigeons still
show the deviation to the left.

The effect of shifting is considered in relation
to the recent hypotheses concerning orientation
and the possible interpretations of the findings
are discussed. (Translated summary.)

Vélker, Hans. Uber die tagesperiodischen
Schwankunken einiger Lebensvorgange des
Menschen. (On the daily periodic fluctua-
tions of some life processes in human beings. )
Pflugers Archiv fiir die gesamte Physiologie,
1927, 215, 43-77.

1. The observations with trained subjects in
Hamburg and Akureyri (Northern Iceland)
showed that there is a circadiane fluctuation
not only for the body temperature but that the
same behavior can be observed in all life proc-
esses investigated (pulse, blood pressure, gas
metabolism, basal metabolism, kidney secre-
tion). On the basis of this we can conclude
that there is a daily periodicity of life processes
in general.

2, The experiments, which were conducted
under a wide variety of conditions, and in which
maximum clarity was aimed at through the
elimination of‘ as many sources of disturbance
as possible, revealed increasingly normal curves,
as the arrangement was made increasingly
simple. Fasting experiments give a clearer
picture than experiments involving food intake;
experiments involving bed rest gave a clearer
and more definite picture than experiments
involving light laboratory work.

3. The effect of these factors on periodicity
consists in a shift, primarily of the minimums;
the values are shifted further and further away
from the normal (standard) point the greater
the sum of the opposite forces here — until an
excessively large quantity finally conceals it
(them). This was clearly proved in a series of
experiments with an increased effect from new
factors which could always be measured. All
reports about a successful inversion of perio-
dicity could thus be easily explained.

4. The circadiane periodicity is fixed on the
basis of local time; it does not depend on the

-~15—



AVIATION MEDICINE TRANSLATIONS:
ANNOTATED BIBLIOGRAPHY OF RECENTLY
TRANSLATED MATERIAL. III.

Abderhalden, Emil, and Grigorescu, L. Weitere
Untersuchungen uber das Verhalten des
Blutserums: gegenuber Rohrzucker vor und
nach erfolgter parenteraler Zufuhr dieses
Disaccharids. (Further investigations on the
behavior of blood serum towards sucrose be-
fore and after parenteral administration of
this disaccharide [dogs were used as experi-
mental animals].) Zeitschrift fiir physio-
logische Chemie, 1914, 90, 419-436.

Results of an experiment designed to investi-
gate the ability of blood serum to decompose
sucrose into its component parts are presented.
The disaccharide was administered parenterally
to a small group of adult dogs. Data obtained
in the study are not uniform, as the presence
of invertase was not always indicated after
sucrose administration. Presence of invertase
also varied from animal to animal with the
amount of sucrose administered and with the
length of the administration period.

The results of the present investigation are
discussed in the light of previous studies, and
an explanation of observed variability of be-
havior toward parenterally administered sucrose
is offered in terms of individual differences in
diet.

Observed physiological measures are given
for individual animals in a series of
experiments.

Abderhalden, Emil, and Wildermuth, F.
Weitere Untersuchungen itber das Verhalten
des Blutserums gegenitber Rohrzucker vor
und nach erfolgter parenteraler Zufuhr
dieses Disaccharids. Versuche an Kaninchen.
(Further studies on the behavior of blood
serum toward sucrose before and after par-
enteral supply of this disaccharide. Experi-
ments with rabbits.) Zeitschrift ftir physi-
ologische Chemie, 1914, 90, 388-418.

An investigation was carried out to determine
the behavior of the blood serum of rabbits to~
ward. sucrose.

The serum of normally-fed rabbits was not
found to decompose sucrose, whereas hydrolysis
of the disaccharide took place regularly when
it was administered parenterally.

Also examined were the ability of rabbit
serum to decompose lactose, dextrose, and
other sugars, and the possibility of reactivation
of inactivated sucrose. Data obtained in the
present study are discussed in view of results
reported by other experimenters.

Obtained values are reported individually for
all experimental animals.

Aschoff, Jurgen. Tierische Periodik unter dem
Einfluss von Zeitgebern. (Animal periodi-
city under the influence of time-setters.)
Zeitschrift fur Tierpsychologie, 1958, 15, 1-30.

-1-



FOREWORD

This annotated bibliography of recently translated, selected research
papers is presented as a scientific service of the Civil Aeromedical Research
Institute and the FAA Medical Librarian. The aims of the publication are:
(a) to provide interested researchers with information concerning transla-
tions of foreign-language articles as soon as the translations are available;
and (b) to prevent duplication of translation costs and efforts.

In achieving these aims, bibliographic listings such as the present one
are necessarily limited in number. They are also limited by the range of
activities represented in the agency preparing the material. Thus, selective
factors exist. Further, no attempt is made to evaluate the scientific worth
of a given article. However, by providing a central repository from which
such translated material can be obtained, it is hoped that interested scien-
tists will derive otherwise unavailable benefits.

Copies of the translated material cited in this report may be obtained
by writing to:

Medical Librarian, HQ-640
Federal Aviation Agency
Washington, D. C., 20553

Please provide the librarian with the complete reference information.


transport: Medico-physiological aspects.) La
Presse Médicale, 1962, 70, 1689-1691.

The next decade will probably see the ad-
vent of supersonic airliners flying at two or
three times the speed of sound. That will be
the greatest step forward in commercial avia-
tion since its birth. There are still immense
problems to be solved before this step can be
taken.

The predicted flight altitudes (15 to 25 km)
necessitate a cabin rigorously secured against
any failure, since any lesser means of protec-
tion is inadequate against the lightning-quick
death that awaits man in the stratosphere. The
ozone of high altitudes, because of its toxicity,
must be eliminated from the air of the cabins.
The speed of flow of the air will generate an
intense heat, so that a system of refrigeration
will be necessary. The high sound level of
aerodynamic noises will call for extreme sound-
proofing. Several tons of equipment will have
to be included in the weight estimates solely
to insure the comfort and safety of the
occupants.

These planes can be put into service only
after months and probably years of experimen-
tation and training. They will have to be bet-
ter adapted to man, but that will not relieve
the crews of the necessity of a difficult recon-
version of their methods of work and their
reflexes.

Much remains to be done before the first
supersonic commercial plane flies, and espe-
cially before it can dethrone the present sub-
sonic jets by offering the same regularity and
safety. It will get there, we cannot doubt,
thanks to the universal law of man in progress.
No doubt the utility of this progress will not
be apparent to all, when so much remains to be
done in other fields. (Translated summary
and conclusions. )

Mercier, A. La vision dans l’aviation
@aujourdhui. (Vision in aviation today.)
In Mercier, A. (Ed.), Visual Problems in
Aviation Medicine, N. Y.: Pergamon Press,
1962, pp. 1-16.

It appears that the new flying conditions
created by the utilization of jet aircraft, the

performances of which are each year higher
and higher, may bring about more marked vis-
ual effects.

Though considerable importance should be
granted to psychotechnical tests permitting the
evaluation of the rapidity and completeness of
sensory-psychomotor reaction times, it must be
admited that, as machines have now exceeded
human possibilities, electronic devices will be
more and more called upon to supply the de-
ficiencies of some physiological functions.

Pilots’ psycho-physiological balance should
also be subjected to check-ups at regular in-
tervals, in order to prevent the appearance of
sensorial illusions and combat the emotive
shock resulting from lonely flight in an empty
sky.
Varifying a 10/10 visual acuity and emme-
tropia at the initial examination no longer as-
sures the safety of vision in all circumstances
because of space myopia appearing in an empty
visual field.

Eye protection against dazzle raises a prob-
lem more and more urgent as the altitude in-
creases. Goggles, visors and tinted glass can-
opies should have at least a 75 per cent
absorption coefficient.

Higher landing speeds and the ever more fre-
quent use of helicopters give a new importance
to oculo-motor equilibrium and_ stereoscopic
vision.

Either in the case of aircraft in which air-
crews are subjected to wearing constantly an
oxygen-breathing apparatus, or in the case of
pressurized cockpit planes, the supply of oxy-
gen must be given considerable care, as the
first effect of anoxia is a disturbance of vision.

Night and twilight vision control and train-
ing should be effected. periodically so as to en-
sure the maintenance of one of the most im-
portant visual functions in flight. (Translated
summary. )

Mercier, A., and Perdriel, G. L’entrainement
de la vision nocturne. (Training for night
flying.) In Mercier, A. (Ed.), Visual Prob-
lems in Aviation Medicine, N. Y.: Pergamon
Press, 1962, pp. 84-88.

The importance, for combatants in general,
and more particularly for aviators, to acquire

-ll-



employed by the Civil Aviation Administration
in 1960 and 1961.

This examination found 31 neuroses (32.5
percent), mostly light. In another institution
(Institution X), 32 wireless operators were ex-
amined and 18 cases of neurosis found (56
percent).

The smaller number of neuroses among the
employees of the Civil Aviation Administration
can be explained primarily in terms of a good
selection process. These employees were posi-
tively motivated toward their occupation in
most cases, their general and specialized train-
ing was better than in Institution X, and they
tended to regard their jobs as temporary solu-
tions in fewer cases than in Institution X. The
quality of the selection procedure in civil avia-
tion is evident in the fact that 27 persons under-
went psychiatric examinations twice over a
period of several years without.any change in
the incidence and severity of neurosis in their
group. The lesser incidence of neurosis in the
Civil Aviation Administration is also due to
the concern there with the further specialized
training of their employees, to better interper-
sonal relations on the job, and to the opportuni-
ties for advancement.

This is to suggest that factors not directly
associated with work are of great importance in
the origins of neuroses among those undergoing
examination.

We found among the employees examined
that unfavorable conditions for development in
childhood predispose the person to develop a
neurosis.

In endeavoring to improve the selection pro-
cedure, we adapted the Minnesota Personality
Inventory for use in the Serbocroatian language
and found somewhat more introverted person-
alities than extroverted ones among the em-
ployees of the Civil Aviation Administration,
confirming to an extent our presupposition that
introverted personalities are more suited to this
type of work.

We found that success on the job is markedly
poorer in the case of severe neurosis.

We note that there are more compulsive
neuroses among wireless operators than among
the general population. Of 31 neurotic patients,

two were suffering from coordinational occu-
pational. neuroses.

Working conditions, particularly the great
emotional strain generated by the responsibility
of the job, had caused fatigue among 14 of the
95 civil aviation employees examined.

The unique phenomenon called by us “being
glued to letters” was observed among wireless
operators in the sense of constant errors with
a particular letter in 21.6 percent. This sign of
fatigue occurred more often in the neurotics.
We hypothesized dissociation or compulsive
phenomena.

To reduce the incidence of neurosis in wire-
less and flight control services in the future,
the selection procedure for choosing candidates
for, appointment to such positions ought to
utilize the experience gained in the course of.
this work. (Translated conclusion. )

Schmidt-Koenig, Klaus. Experimentelle Ein-
flussnahme auf die 24-Stunden-Periodik bei
Brieftauben und deren Auswirkungen unter
besonderer Berucksichtigung des Heimfin-
denvermégens. (Experimental influence on
24-hour periodicity in pigeons and its effect
with special reference to homing capability. )
Zeitschrift fur Tierpsychologie, 1958, 15,
301-331.

Pigeons were subjected to different conditions
of artificial light (shifted phase, change of fre-
quency, constant illumination) in lightproof
rooms. The influence on the endogenous time
mechanism was investigated with reference to
three criteria: (A) relief times during incuba-
tion; (B) direction-finding of pigeons trained to
a compass direction; (C) homing orientation
of shifted pigeons.

A. The incubation relief schedule readily
follows the shift in light-dark rhythm. The
rhythm loses its hold under constant illumina-
tion and shows irregularities even under re-
duced amplitude of illumination (twilight in-
stead of darkness). The adaptation to 10-hour
“night” and 10-hour “day” alternation is only
incompletely achieved. The rhythm depends
mainly on the light-dark cycle. There is a
slight but noticeable dependence on the en-
dogenous diurnal periodicity of approximately
24 hours.

~14—