COLOR, VISION, AND PHYSIOLOGICAL OPTICS

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B05171A000600070048-5
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 3
• Document Creation Date: December 28, 2016
• Document Release Date: April 7, 2003
• Sequence Number: 48
• Content Type: OPEN

BALLROOM 3 AT 9:45 A.M.
TIIURSDAY, IA ~ F Bk lease 2003/05/14: CIA-RDP78B05174 00600070048-5
GUNTER W. WYSZECKI, Chairman
Color, Vision, and Physiological Optics
ThDll. Two Types of Threshold Sensitivity in the Blue
Region of the Spectrum.GILBFRT B. Lac, Department of
Ophthalmic Surgery, University of Michigan, Ann. Arbor,
Michigan 48104.-Three different luminosity clove types
obtained from color normal subjects were previously dc-
scribed.' These were type-A, the largest group, resembling the
classic CIE photopic curve; type-B, the dcutan-looking group
showing a sensitivity loss in the blue and blue-green region;
and type-C, the protan or red weak group. More recent work
is being reported now on two of these groups, type-A and
type-B. Using a modified Stiles foveal-threshold sensitivity
technique' one receptor mechanism ata time was altered (light-
adapted) while 30 points at 10-nm intervals through the spec-
trum were studied. A a?-target flashing once/sec from a Hilger
monochromator was centered in a 3.5?-field of moderately
bright colored light (red; green, and blue). The subject ad-
justed the intensity of this stimulus test [lash (0.040 sec) to his
increment brightness threshold. Four type-A subjects and five
type-B subjects were tested. All of the type-A group showed a
loss in sensitivity to blue under blue light. None of the type-B
group showed this. Their blue-adapted sensitivity threshold
curves were indistinguishable in shape from their brightness-
matching luminosity curves. (13 min.)
I G. B. Lee, J. Opt. Soc. Am, 56, 1451 (1966).
2'N. S. Stiles, Science 145, 1016 (1964).
ThD12. Metamerism and Color-Rendering Indexes. 1.
NIMRROFF, National Bureau of Standards, Washington, D. C.
20234.-The color of fluorescent lamps, which emit spectral
flux that consists of spectral lines and a continuum, has been
customarily designated by the correlated color temperature,
the temperature of a blackbody whose chromaticity most
nearly matches that of the lamp. When this practice was found
to give inadequate descriptions of the spectral characteristics
Declass Review by NIMA/DOD
Approved For Release 200?/05/14 : CIA-RDP78BO5171A000600070048-5
 Approver Release 2003/05/14: CIA-RDP78B0690Aj Q9 q?QT0048-5
SOCIETY A 15
1968 ANNUAL MEETING OPTICAL
of these lamps and the color appearance of objects illuminated
by them, a general color rendering index' was devised, supple-
mented by special color-rendering indexes. The calculation of
general color-rendering index is a long procedure that involves
the spectral characteristics of eight colored surfaces to sample
the color gamut, two sources (the lamp and its nearest-match-
ing blackbody), and the three CIE standard-observer func-
tions. But, as these two sources are metameric matches
(spectrally different color matches), a metameric index to
describe the degree of spectral.,mismatch may be all that is
required. In computing the gnetanlerism index' only the
spectral data of the two sources and the three standard-
observer functions are needed. The correlation between the
general color-rendering index and the metamerism index,
obtained for six types of fluorescent lamps was found to be
very high, 96% (10 min.)
I CIE Publication No. 13 (E-1.3.2) 1965 (Bureau Central de la Commission
Internationale de l'Eclairage, Paris, France).
8 I. Nimeroff and J. A. Yurow, J. Opt.Soc. Am. 55, 185 (1965).
Ironies Command, Night Vision Laboratory, Fort Belvoir,
Virginia 22060.-Electro-optical systems display video in-
formation to the eye of an observer. This paper is concerned
with the modulation transfer function describing that part of
the information which is perceived by the observer. The effect
of noise on the modulation transfer function was studied by
means of threshold measurements. White noise and 1/f noise
of various levels and different cut-off frequencies were dis-
played on a television screen together with a sinusoidally
modulated bar pattern. The signal-to-noise threshold for
perception was measured as a function of the spatial frequency
of the bar pattern. It was found that the signal-to-noise
threshold, in addition to being strongly dependent on the bar
pattern frequency, is also dependent on the rms value and the
frequency distribution of the noise and on the difference be-
tween the bar pattern frequency and the mean frequency of the
noise. An attempt was made to explain the results by observa-
tion of the recognition of the bar pattern in the presence of
narrow bandwidth noise. (13 min.)
ThD13. Matrix Model for Color Perceptability Ellipsoids.
K. D. CIIICIiERING, Kollmorgen Corporation Holyoke, Massa-
chusetts 01040.-A model relating aspects of both the Yount
Helmholtz trichromatic theory and the Hering opponent
response theory' is presented in a matrix-vector form. The
model converts a vector in the system in which physical color-
difference measurements are described in two stages to a vector
in the system in which the eye responds to that difference. An
orthogonal matrix operator is considered which transforms the
perceptability ellipsoid to canonical form. The last operator
results in a vector representing the conscious response of the
brain as the final step in the process of color-difference per-
ception. Influenced by the Friele model' and the resulting
FMC equations 3,4 this more general model contains, when
suitably rewritten, the FMC equations as a special case. When
applied to experimental data such as those of Brown-Mac-
Adam,' the model can be used to show that the perceptability
thresholds should be the positive square roots of the eigen-
values corresponding to the matrix of color-metric coefficients
in the visual system. (13 min.)
' A. Meessen, J. Opt, Soc. Am. 58, 702 (1968).
8 L. F. C. Friele, J. Opt. Soc. Ain. 55, 1314 (1965).
8 D. L. MacAdam, J. Opt. Soc. Am, 56, 1784 (1966).
' K. D. Chickering, J. Opt. Soc. Am, 57, 537 (1967).
6 W. K. J. Brown and D. L. MacAdam, J. Opt. Soc. Am. 39, 808 (1949).
ThD14. Visibility of Colors Underwater Using Artificial
Illumination. Jo ANN S. KINNEY, S. M. LURIA, AND DONALD
0. WEITZMAN, Naval Submarine Medical Center, Naval Sub-
marine Base New London, Groton, Connecticut 06340.-The
visibility of various colors underwater with artificial illumi-
nation has been, measured in three different bodies of water.
Subjects were SCUBA divers who observed the colors at night,
using a mercury and an incandescent light source. The waters
were selected to sample the continuum from very murky to
clear. Colors were chosen to be representative of commercially
available paints in both fluorescent and nonfluorescent types.
The data are analyzed in tern's of the most and least visible
colors for the two lights and the various water clarifies.
Numerous interactions are found between color, fluorescence,
light source, and water; from these results, it is possible to
select the optimum combination to be used under a wide
variety of conditions. These data extend the work of a previous
investigation' in which similar experiments were performed
using natural illumination conditions. (13 min.)
J. A. S. Kinney, S. M. Luria, and D. O. Weitzman, J. Opt. Soc. Am. 57,
802 (1967).
ThD15. Effect of Noise on the Modulation Transfer Function
of the Visual Channel. HERBERT POLLEIIN (introduced by
Werner K. Weihe) AND HANS ROEIIRIG, U. S. Army Elec-
ThD16. Impulse Response of the Human Visual System.
JOAN L. LEVINSON, Bell Telephone Laboratories, Inc., Murray
Hill, New Jersey 07974.-It is not enough to know the "fre-
quency characteristic" of the visual system. (Frequency
characteristics were introduced to vision by de Lange, who
used sinusoidal modulation of otherwise steady light to
produce flicker of independently variable frequency and
amplitude.) A general stimulus may include components of
several different frequencies at once, and even if these com-
ponents combine linearly, the result is not computable unless
the delays of the various frequencies are also known. How to
measure delay without resort to microelectrodes? Previous
psychophysical experiments have given ambiguous results.
But a system may be described completely in another manner,
namely, by its impulse (i.e., flash) response. Impulse response
and frequency characteristic (including phase, or delay) are
related by a Fourier transformation. It is shown that a linear
system responds with greatest amplitude to a signal consisting
of its impulse response reversed in time, if signals of "equal
energy" are compared. Thus the problem reduces to finding
that flash waveform to which the observer is most sensitive,
under the restriction to waveforms for which the integrated
square of the modulation amplitude is the same. (13 min.)
ThD17. Wavelength Difference Thresholds for the Detection
of Square-Wave Gratings.* R. HILZ (introduced by C. R.
Cavonius) AND C. R. CAVONIus, The Eye Research Foundation,
8710 Old Georgetown Road, Bethesda, Maryland 20014.-Wave-
length discrimination functions were measured from 480 nm
to 660 nnl at spatial frequencies between 2.3 cycles/degree and
18.4 cycles/degree. The wavelength difference needed to
resolve gratings increases with spatial frequency in all parts of
the spectrum, so that the shape of the wavelength discrimina-
tion function changes very little over a wide range of spatial
frequencies. Unlike luminance difference thresholds, which
often go through a minimum at low spatial frequencies, the
wavelength difference threshold shows no minimum within the
frequency range tested. This agrees with the results of van der
Horst et al.' The effect of small suprathreshold luminance
differences between adjacent grating bars was also investi-
gated. Wavelength measured with gratings is generally im-
proved by the introduction of these luminance differences.
Also, the shape of the wavelength difference threshold (vs
spatial frequency) function is changed by the introduction of
luminance differences. (13 min.)
* Work supported by the Office of the Surgeon General, U. S. Army.
i G. J. C. vats der I-Iorst, C. M. M. de Weert, and M. Bouman, J. Opt. Soc.
Ain. 77, 1260 (1967).
Approved For Release 200?/05/14 : CIA-RDP78BO5171A000600070048-5
 Approvedr Release 2003/05/14: CIA-RDP78BOW 1A000600070048-5
1968 ANNUA . MEETING ? OPTICAL SOCIETY OF AMERICA
ThD18. Cortical and Subcortical Responses to Flicker.
JOSEPH F. STURR, VONNELL G. MASTRI, JOSEPH I. MARKOrF,
MICHAEL S. SHANSKY, AND EHUD KAPLAN, Department of
Psychology, Syracuse University, and Syracuse Veterans
Administration Hospital, Syracuse, New Yorle 13210.-Bipolar
recordings were taken from cortex (VI) and deeper structures
(OT, LGB, and radiations) in 35 anesthetized cats. A square-
wave pulse train of 400 cosec was presented to the right eye at
three photopic luminances, at frequencies ranging from 7.5 to
100 Hz. Photic following or entrainment was defined as fre-
quency-specific responses to the stimulus. In general, although
the deeper structures followed up to the limits of the equip-
ment (100 Hz), cortical following did not extend beyond
30-50 Hz. Above 20 Hz, entrainment in cortex and subcortex
was preceded for approximately 100 msec by an initial re-
sponse. The amplitude of the entrained response was syste-
matically attenuated at higher frequencies. Below 20 Hz,
entrainment appeared immediately, often with double re-
sponses to each pulse in the flicker train. The effects of levels
of anesthesia are discussed. (13 min.)
ThD19. Directional and Nondirectional Auditory Feedback
in Control of Eye Position. SAMUEL C. MCLAUGHLIN, MICHAEL
J. DESISTO, AND MARTIN BRESLOW, Department of Psychology,
Tufts University, North Hall, Medford, Massachusetts 02155.-
The experiment started with S looking at a point of light in
an otherwise darkened room, his eye position being monitored
continuously by measurement of diffuse infrared reflectance
from the external limbus. After 5-10 see, the light was turned
out, and S was instructed to "keep looking where the light
was" for 20 sec. Whenever his eye drifted from its starting
position by 1 ? or more, S heard an auditory signal. It has
been shown [W. Smith, Psychon. Sci. 1, 233 (1964)] that
eye position is more stable in the presence of such an auditory
signal than in its absence-i.e., that S is able to use the
auditory information as a surrogate for the missing visual
feedback. In the present experiment, we evaluated stability
of ocular position in the presence of each of two types of
auditory feedback: a "non-directional" signal which was
delivered to both ears; and a "directional" signal which was
delivered to one ear or the other depending on which way
the eye drifted off target. For each of three S's, the directional
signal was more effective in keeping the eye "on target."
(13 min.)
ThD20. Energy Level Models of Binocluar Vision. GEORGE
SPERLING, Bell Telephone Laboratories, Inc., Murray Hill,
New Jersey 07974.-The classical energy-level model consists
of a marble rolling freely on a bumpy energy surface. Dips on
the surface (energy-wells) represent stable states in which the
marble becomes trapped. This classical model is applied to
three major processes of binocular vision: accomodation (a),
vergence (v), and fusion (f). Here the lateral position of the
marble represents the instantaneous value of the depth plane
of a (or v or f). For example, the basic surface governing
vcrgenee is bowl-shaped, this shape being determined by
internal factors. The marble always rolls to the center of the
bowl, representing the tendency of the eyes to verge to a
neutral position in the absence' of a stimulus to vergence. The
external stimulus adds perturbations to the basic surface,
creating new stable states. This simple model serves nicely to
illustrate the path-dependence of vergence (e.g., different
vergence states may occur with the same external stimulus),
and it shows how extreme values of vergence can be achieved.
Similar properties are proposed for a and f systems, and a
complete model is presented to account for the a-v-f inter-
actions. Although the energy models of a, v, and f are formally
similar, the proposed underlying neural mechanism of fusion
is fundamentally different from the others. It depends on a
binocular neural field which, at any spatial x, y coordinate,
permits fusion at only one depth plane and suppresses other
possible fusion modes. (10 min.)
ThD21. Enhanced Sensitivity Associated with Saccades.
WHITMAN A. RICHARDS, Massachusetts Institute of Technology,
Cambridge, Massachusetts 02139.-Most previous studies which
show an elevation of t'resholds associated with the saccade
have used test-flashes presented against a background. No
saccadic effect was found, however, in at least one study using
no background.' These differences imply that the background
level may be an independent variable which can alter the
effects of saccades on thresholds. To examine this variable,
foveal thresholds for a test-flash which followed a saccade by
40 cosec were determined at 13 wavelengths for two real-light
backgrounds, 471 and 645 nm. In each case, the maximum
suppression associated with the saccade occurred for wave-
lengths in the neighborhood of the background wavelength.
This suggests that the effect of the saccade is to raise the noise
of the real-light background rather than to attenuate the
incoming test-flash signal. A second study of the importance of
background activity compared the effects of a real-light back-
ground vs its after-image. Contrary to what is found for a
real-light background, the flash could be detected much more
readily against the after-image if a saccade had been made.
This observation of "saccadic enhancement" is as if the effect
of the eye movement is to wipe-out that part of the background
noise associated with the after-image, thus improving signal
detectability. These differences between the real-light and
after-image backgrounds may be interpreted as a release of
lateral inhibition following the saccade. (13 min.)
I J. Krauskopf, V. Graf, and K. Gaarder, Am. J. Psychol. 71, 73 (1966).
ThD22. Computer Analysis of the Electroretinograms.
STANLEY BUCKSER, Department of Biology, East Carolina
University, Greenville, North Carolina 27834.-A simple model
was assumed regarding the eiectroretinogram (ERG) as the
summation of potentials produced by three different processes
initiated by a light flash stimulus. The first process corresponds
to the initial negative potential, the a-wave. Rising from the
a-wave with positive polarity is the rise portion of the b-wave,
the second process. The b-wave reaches a maximum and falls
off in the decline portion of the b-wave, represented by the
third process. Each of these processes is assumed to have the
form: f(t)=C?(1-exp[-k(t-J)]}. These functions can be
derived from physiological phenomena, e.g., ion diffusion
across a membrane with the observed potential being propor-
tional to the difference in concentration between intracellular
space and the surrounding medium. A series of ERG's was
obtained from a curarized dark-adapted albino rat response
to a constant light stimulus during various stages of anoxia.
This fractionates the a-wave as the ERG b-wave decreases
with increasing anoxia, and finally disappears, leaving only the
a-wave. This is reversible when oxygen is supplied. Five curves
of this series at different stages of anoxia were digitized and put
in a form suitable for processing by the IBM 7094 computer.
Programs were written which systematically vary the param-
eters of the model in such a way as to reduce the sum of squares
of differences between the model and the experimental data.
Final parameters are obtained when the algorithm can no
longer reduce the sum of squares. The fit between the experi~
mental data and the summated functions of the model for the
various stages of anoxia is examined and a view of each
process, uncomplicated by the others occurring in the same
ERG, is obtained. A discussion of the basic parameters and
others derived from the model and their change with anoxia
is given. (13 min.)
Approved For Release 200?/05/14 : CIA-RDP78BO5171A000600070048-5