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HALDAN KEFFER HARTLINE
December 22, 1903-March 1S, 1983
BY FLOYD RATLIFF
FOR MORE THAN HALF A CENTURY Haldan Keffer
Hartline, Keffer to friends and close colleagues, conduc-
ted biophysical research on vision and the retina. He stucl-
iec] retinas from arthropods, vertebrates, and molluscs the
three major phyla with well-developec! eyes and his investi-
gations extended into many ant! diverse branches of the field.
During this long career Hartline elucidated numerous funcia-
mental principles of retinal physiology, laying the foundations
for the present-clay study of the neurophysiology of vision.
Hartline's four major accomplishments were all "firsts" in
their respective fields: With Clarence H. Graham he re-
corded the activity of single optic nerve fibers. He mapped
the activity of the visual receptive field to reveal a system of
many convergent pathways from many photoreceptors (the
foundation for modern concepts of parallel processing
by specialized channels). He recorded with Wagner ant!
NIacNicho!—intracellular generator potentials. And finally,
he discovered lateral inhibition in the retina and describecl
the integrative activity of neural networks with the Hartline-
Ratliff equations.
EDUCATION AND EARLY LIFE
Keffer Hartline was born on December 22, 1903, in
Bloomsburg, Pennsylvania, to Daniel Schollenberger
197
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BIOGRAPHICAL MEMOIRS
Hartline and Harriet Franklin Keffer Hartline. His father
taught science and his mother English at the Bloomsburg
State Normal School (now Bloomsburg State College) where
the young Hartline receiver! his early formal education. Per-
haps more significant to the young Kepler was the informal
but intensive training he received at home as an only chilcI.
Both of his parents hacI a strong interest in the natural world
around them, an interest that deeply affected the young Kef-
fer. Indeed, he was later to refer to his father as "my first ant!
best teacher," and the love of nature his parents instiller!
surely influenced his choice of experimental research in biol-
ogy as his lifelong career.
Upon completion of his studies at Bloomsburg in 1920,
Hartline spent the summer at the marine laboratory in Cold
Spring Harbor, I,ong Island, taking a six-week course in com-
parative anatomy. That fall he enterer} Lafayette College to
study biology and was encouraged by Professor B. W. Kunke!
to do research. Hartline was much impressed by Jacques
Loeb's quantitative work on tropisms, and his very first ex-
.
percents p ~ototropic responses of lancl isopods were
along the same lines. At Woods Hole in the summer of 1923
he showed the results of his experiments to Loeb, who en-
couraged him to publish the work in the journal of General
Physiology. Loeb also introduced Hartline to the biophysicist
Selig Hecht, who was just coming into prominence in the field
of vision research. That fall, Hartline entered the Johns Hop-
kins University School of Medicine.
Fincling time at Hopkins to continue his research, he came
under the influence of E. K. Marshall, head of the Depart-
ment of Physiology, anti, even more strongly, of Charles D.
Snyder. Snyder taught Hartline how to use and replace the
inevitable broken strings on a string galvanometer, then gave
him free access to that clelicate instrument. Hartline bore out
his confidence and soon thereafter published pioneering
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HALDAN KEFFER HARTLINE
199
work on the retinal action potential he hac! recorded from a
variety of species, including humans. His early research
helped lay the groundwork for modern electroretinography.
In 1927, Hartline received the M.D. degree from Hopkins
but—clearly more interested in research never went on to
· · ~
practice mec lclne.
Remaining at Hopkins for two years as a National Re-
search Council Fellow, Hartline ctecided, after a brief expo-
sure to quantitative experimental biology, to study mathe-
matics and physics. Drawn to these disciplines, he went so far
as to consider a career in either one or the other. On a ~ohn-
son Research Scholarship from the Elciridge Reeves Johnson
Foundation, he went to Germany to study uncler Arnold
Sommerfelct at Munich and uncler Werner Heisenberg at
Leipzig. It soon became evident, however, that Hartline
lacked the background! for these advanced courses and lec-
tures, and disappointed! with the outcome of this venture-
he returnee! to the United States after one year to take up his
first appointment in biology. Hartline's interest in mathemat-
ics and physics never waned, ant! his approach to experi-
mental biology remained! rigorously quantitative and based
on sound physical principles.
PROFESSIONAL CAREER
Detlev W. Bronk, director of the Elciridge Reeves Johnson
Foundation at the University of Pennsylvania from 1929, was
quick to recognize genius and soon offered Hartline a posi-
tion as a fellow in medical physics. This proved ideal for the
frustrated theoretical physicist, ant! Hartline remained at the
Johnson Foundation from 1931 until 1949 (except for a brief
and unsuccessful move, with Bronk, to Cornell University
Medical College from 1940 to 1941~.
While at the Johnson Foundation, Hartline met a number
of investigators who later became prominent in vision re-
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. .
BIOGRAPHICAL MEMOIRS
search. Among these were psychologists Clarence H. Graham
and Lorrin A. Riggs, who became his research collaborators,
ant} physiologist William A. H. Rushton, who turned to vision
research in his later years. It was also at the Johnson Foun-
clation that Hartline first met the neurophysiologist Ragnar
Granit. While at Woods Hole he became acquainted with the
biochemist George Wald. Hartline, Granit, and Walt! each
went his inclependent way in vision research, following the
work of the other two closely ant! admiring it, but never
working together in collaboration. They little dreamed
that a quarter of a century later—they wouIc! share the No-
be! Prize.
In 1949, Bronk accepted the presidency of the Johns
Hopkins University on the condition (among others) that a
biophysics department be established on the Homewoocl
campus. He appointed Hartline the first professor of bio-
physics and chairman of the new Thomas C. Jenkins Labo-
ratory of Biophysics. There Hartline continued his earlier
close association with Henry G. Wagner and E. F. (Ted)
MacNichol, Jr., while electronics engineer John P. Hervey and
instrument maker Walter Biclerlich provided valuable sup-
port services. ~ first met Hartline in 1950 when ~ joined his
laboratory on a one-year National Research Council fellow-
ship. We felt an instant rapport and would work together in
close collaboration for the next twenty-five years.
In September of 1953, Bronk became president of the
Rockefeller Institute for Medical Research (later The Rocke-
feller University) and immediately appointed Hartline a
member and head of the Institute's Laboratory of Biophysics.
Within the year, Hartline invites! me to leave Harvard for
The Rockefeller, and ~ immediately accepted. Over the next
few years we were joined by William H. Miller, Bruce W.
Knight, fir., Frederick A. Docige, fir., and electronics engineer
Norman Milkman. When the Rockefeller Institute became
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HALDAN KEFFER HARTLINE
201
The Rockefeller University, Hartline was appointed profes-
sor ant! heat! of laboratory. He never left The University
thereafter for any extended period, except for a sabbatical
leave as George C. Eccles Professor at the University of Utah
in 1972. That same year, he was named DetIev W. Bronk
Professor at The Rockefeller, the post he held until his re-
tirement until 1974.
MAJOR SCIENTIFIC CONTRIBUTIONS
Single Optic Nerve Fibers
In 1927, Ecigar D. Acirian and Rachel Matthews success-
fully recorder! electrical activity in an optic nerve, though—
in this early work (on the eye of the eel)—they were only able
to recorc! the massive discharge of the whole nerve trunk.
Adrian ant! Bronk later managed to dissect and isolate a
single fiber of the phrenic nerve ant! record its activity.
Inspired by their success, Hartline and Graham under-
took similar studies on the optic nerve of the horseshoe
"crab," Limulus. The compound eye of this venerable animal,
with its large photoreceptors and long optic nerve, was ideally
suited for this study, and in 1932 they were able to record
the activity of single optic nerve fibers for the first time. Their
research showed that impulses transmitted by an optic nerve
fiber are essentially iclentical and that information about the
intensity of light incident on the photoreceptor is coaled in
terms of the rate of discharge of impulses rather than the
shape or amplitucle of incliviclual impulses. Here began the
direct, quantitative, experimental investigation of informa-
· · · .
tlon-processlng in t he vlsua system.
The techniques used by Hartline and Graham also pro-
vided an indirect but proximate method for studying the
physical and chemical events in the photoreceptor that give
rise to nerve impulses. In 1935, for example, the two re-
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BIOGRAPHICAL MEMOIRS
searchers usect it to determine the spectral sensitivity of the
Limulus photoreceptor. Later, with P. R. McDonald, they mea-
surec! light ant! dark adaptation. Twenty-five years later Ruth
Hubbard and George WalcI confirmed the precision and re-
liability of Hartline's early spectral measurements by extract-
ing the photopigment from the eye of L,imulus to determine
its spectral absorption by direct methocis. The two curves
agreed almost point for point.
The Receptive Field
In his early research at the Johnson Foundation and later
at Johns Hopkins and Rockefeller, Hartline nearly always
worked in collaboration with other investigators. In all of
these collaborations, however, there was never a question in
anyone's minct about who was the master and who the ap-
prentice. Though unquestionably a brilliant collaborator,
Hartline's extraordinary ability and unique talents produce
the most startling results cluring the period of his thirties ant!
forties when he worked alone. The single-handed investiga-
tions, mainly on the vertebrate retina, of those years are per-
~ · · -
~aps nits most s~gn~hcant contra button to science.
With his exquisite microctissection technique, Hartline
was able to isolate single optic nerve fibers of the vertebrate
retina and, for the first time, record their activity. He found
that the response of the whole nerve resulted! from the sum-
mated activity of fibers whose individual responses differed
markedly. Some fibers discharged steadily in response to
steady illumination, some in response to the onset ant! ces-
sation of illumination, others only to its cessation. Many fibers
showed extreme sensitivity to moving patterns of light and
shade. Mapping the "receptive fielcls" of some of them in
detail showed that a retinal ganglion cell can receive excita-
tory and inhibitory influences over many convergent path-
ways from many photoreceptors. The optic nerve fiber
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HALDAN KEFFER HARTLINE
203
arising from the retinal ganglion cell is simply the final com-
mon pathway.
Hartline fount! that the processing of visual information
begins in the retina with the specialized activity of diverse
types of ganglion cells, thereby laying the foundation for
modern concepts of parallel processing by specialized chan-
nels. "The study of these retinal neurons has emphasized the
necessity for considering patterns of activity in the nervous
system," he remarked in his 1942 Harvey Lecture. "Individ-
ual nerve cells never act independently; it is the integrated
action of all the units of the visual system that gives rise to
vision" ~ ~ 942, ~ ).
The Generator Potential
As early as 1935 Hartline, using external electrodes, had
recorded the local "action current" of a single photoreceptor
unit in the compound eye of Limulus. Simultaneous records
of the propagated impulses in the optic nerve suggested that
this retinal action potential might be the generator of the
impulses. When micropipette electrocles with tips small
enough to penetrate cells were developed, opening the gen-
erator potential to direct stucly, Hartline's earlier interest in
this hypothesis was rekinclled.
Using the new micropipettes, Hartline, Wagner, and
MacNichol recorder! intracellular generator potentials for
the first time anct were able to study the photoreceptor as a
biological transducer relating nerve impulses to a genera-
tor potential, and generator potential to the light incident on
the photoreceptor.
MacNichol, Wagner, and Hartline further observed that
the rate of discharge of impulses was approximately linear
with depolarization of the cell whether incluced by light or
by current passed through the electrode—and that sponta-
neous activity was suppressed by hyperpolarizing current.
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BIOGRAPHICAL MEMOIRS
Hartline's colleague, Tsuneo Tomita, soon demonstrated that
the clepolarization resulted! from an increase in membrane
conductance short-circuiting the resting potential of the cell.
The way was now open to a proper biophysical understand-
ing of the generation of impulses by sensory receptor cells.
The Harttine-Ratli~Equations
One of Hartline's most important contributions to the
physiology of vision was his discovery of lateral inhibition in
the retina of the compound eye of Limulus. It is uncertain
when the discovery of this "lateral effect" (as it was first called)
was actually made, although according to Hartline's best
recollection it was the late 1930s. The first published report
(1949,1) on this pattern of central excitation and surround!
inhibition was long delayed, but even so it predated the dis-
covery of the analogous center-surround organization of the
vertebrate retina.
In our first studies carried out at Rockefeller, Hartline
and ~ focused on a quantitative account of the inhibitory in-
teractions in the eye of L`imulus. We were able with a pair
of simultaneous equations to express the reciprocal inter-
actions between two photoreceptor units in the steady state.
Although these equations were strongly nonlinear overall,
they were, as Hartline put it, "mercifully, piece-wise linear, to
a good approximation." These so-called "Hartline-Ratliff
equations" actually based upon, and testable by, direct elec-
trophysiological measurements provided the first mathe-
matical description of the integrative activity of a real neural
network.
Our subsequent discovery of the phenomenon of "inhi-
bition of inhibition" enabled us to extend the mathematical
description to any number of interacting units. This inhibi-
tion of inhibition or Inhibition as we preferred (following
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HALDAN KEFFER HARTLINE
205
PavIov) to call it confirmed! the notion we had already ex-
pressed in our pair of simultaneous equations describing the
interaction of two elements: the interaction was both mutual
and recurrent. With this knowledge, Hartline and ~ could
now express the interactions among not just two units, but
any number n either with a set of n simultaneous equations,
or, if the number was large enough, with integral equations.
The phenomenon of disinhibition first thought to be unique
to the Limulus retina has since turned out to be a general
principle of neural organization, widespread in the other
species and neural systems.
Our earliest studies of the dynamics of lateral inhibition
with William H. Miller and G. Davis! Lange were purely
empirical, but quantitative, theoretical approaches to the dy-
namics of neural mechanisms were in the air. Attractec! by
the symmetry of responses of the Limulus eye to equal incre-
ments and decrements, Bruce W. Knight, fir., a physicist and
appliecl mathematician, joined the I.aboratory in 1961.
Knight realized that the Limulus eye appeared to be a "time-
invariant linear system" that could be treated as a system of
linear transducers, and that the several transductions could
all be characterizes! by transfer functions.
The transduction from light to generator potential, gen-
erator potential to impulses, and impulses to self- and lateral-
inhibitory potentials were directly measured and character-
izec! as transfer functions, enabling the Laboratory to make
successful theoretical predictions of responses to a wide va-
riety of stimuli. These experiments—performed mainly in
collaboration with Bruce Knight, Jun-ichi Toyoda, and Fred
Docige showed the appropriateness of treating the Limulus
eye as a system of linear transducers over a wale range of
experimental conditions. But Hartline remained wary. "The
trouble with theories," he once said, "is that after a while one
begins to believe them."
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BIOGRAPHICAL MEMOIRS
~ SENSE OF HUMOR
l:lartline's wry humor often produced unexpected and
telling remarks. Capping a discussion of a new laboratory
building on campus much criticizer! by the scientists who hac!
to use it, he said drily that "it must have been designed by an
architect." He was also given to telling tall tales with a straight
face, many of which were taken for truth. His often repeated
assertion that he was "awarded the M.D. on the condition
that he never practice medicine," for instance, was widely be-
lieved. But Hartline's humor was a two-way street, and he
often quoted my own description of his untidy laboratory as
"a slightly disorganized, but extremely fertile, chaos."
HONORS AND AWARDS
While still in medical school Hartline receiver! the William
H. Howell Awarcl in Physiology. I:xperimental and physio-
logical psychologists were among the first to recognize the
importance of his later work to an understanding of human
visual perception, and the Society of Experimental Psychol-
ogists awarcled him the Howard Crosby Warren Medal in
1948. That same year saw his election to the National Acad-
emy of Sciences. He was elected to the American Philosoph-
ical Society in 1962, receiver! Case Institute of Technology's
Albert A. Michelson Awarc} in 1964, became a foreign mem-
ber of the Royal Society in 1966, anti, in 1969, received the
Lighthouse Award for Distinguished Service.
In 1967 the Nobel Prize in Physiology or Medicine was
awarcled jointly to Ragnar Granit (Karolinska Institute), Hal-
cian Keffer Hartline (The Rockefeller University), and
George Wald (Harvard University) "for their discoveries con-
cerning the primary physiological and chemical visual pro-
cesses in the eye."
Ironically, the Nobel Prize for Hartline's contributions to
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HALDAN KEFFER HARTLINE
207
vision research coincicled with a decline in his direct partici-
pat~on in such research. Slowly failing eyesight, a result of
senile macular degeneration, made it increasingly difficult
for Hartline to react and write, to use a microscope, ant! to
perform the highly skilled manual techniques for which he
was noted. "The loss of central vision is bad enough in itself,"
he once remarked, "but to be prematurely labeled senile only
adds insult to injury."
HOPE AND FAMILY
In 1936 Hartline married Elizabeth Kraus, daughter of
the eminent chemist C. A. Kraus, and, at that time, instructor
in comparative psychology at Bryn Mawr College. Mrs. Hart-
line shared her husband's interest in nature and later became
a cleclicatect conservationist. Their three sons Daniel Kepler,
Peter Halcian, and Frederick Flanders tutored by their fa-
ther as he had been by his all became biologists.
When Hartline accepted a position at Johns Hopkins in
1949, the family purchased a house near Hydes, Maryland,
about twenty miles from Baltimore. This country house,
which they called TurtIewood, is still the family home. In
1953, Hartline became a member of the Rockefeller Institute
and moves] to an apartment in New York City. Leaving Mrs.
Hartline and their three sons in Maryland, Hartline returnee!
home for long weekends ant] holidays, viewing the New York
apartment as little more than a "winter camp" in the city. The
family's "summer camp" was the Kraus family place on 01d
Point, just across Frenchman Bay, northwest of Bar Harbor,
Maine.
CONCLUDING REMARKS
Hartline enjoyed god health throughout most of his life
anti, despite his slight stature and rather frail appearance,
was an active out~loorsman. When young he enjoyed moun-
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BIOGRAPHICAL MEMOIRS
tain climbing and had some first ascents to his credit in the
Wyoming Rockies. He pilotecl his own open-cockpit plane
arounc! the country. He enjoyed sailing with Bronk near
their summer home in Maine and, on occasion, with Ragnar
Granit in the Baltic.
Continuing his outdoor activities even into oIc! age, Hart-
line decicled in his seventies to take a long-postponec! rafting
trip through the Grand Canyon. His carcliologist recom-
mendecl against the trip, but Hartline decided that it was now
or never, basing his decision (according to one of his apoc-
ryphal stories) on a favorable second opinion from a der-
matologist. In any event, he and Mrs. Hartline took the trip
and- except for being too coIcl and wet on the raft in the
rapids ant! too hot and ciry on the desert shore both en-
joyecl it immensely.
In his late seventies Hartline's chest pains became more
frequent and severe, and on March I8, 1983 as he was en-
tering his eightieth year he diec! of a heart attack at the
FalIston General Hospital in Maryland.
Keffer Hartline achieved great distinction in every phase
of his half-century of research on the physiology of vision
and was awarder! the highest of all honors in science. Yet he
remainec! modest and unassuming throughout and was
somewhat embarrassed by fame and public acclaim. He spe-
cifically requested that there be no official memorial service
or organized tribute to him at The Rockefeller University,
suggesting rather that one of the University concerts—which
he had enjoyed} so much over so many years would be an
appropriate memorial, bringingjoy to others rather than sor-
row. On March 7, 1984, the Stuttgart Chamber Orchestra,
with Karl Munchinger conducting, played to a full house in
a performance dedicated to Keffer Hartline's memory.
Keffer Hartline and ~ worked together day after day, year
after year, for more than a quarter of a century. The strong
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HALDAN KEFFER HARTLINE
209
bond of friendship between us transcended all time and
place, and all human frailty. To such a friend, the truest trib-
ute is one enshrined in memory and thought, unspoken.
INFORMATION ABOUT HARTLINE S life and work during the pe-
riod of 1903-1950 came from his own reminiscences dictated dur-
ing the last years of his life and transcribed by his long-time secre-
tary, Maria Lipski. The period of 1950-1983 is based primarily on
my own records and firsthand knowledge. For other accounts, see:
John E. Dowling and Floyd Ratliff, "Nobel Prize, Three Named for
Medicine, Physiology Award," Science, 1 58( 1 976) :468-73; Ragnar
Granit and Floyd Ratliff, "Haldan Keffer Hartline, 1903-1983,"
Biographical Memoirs of Fellows of the Royal Society, 31~1985~:262-92;
and Floyd Rashly, "Haldan Keffer Hartline (1903-1983)," Year Book
1984 (Philadelphia: American Philosophical Society), pp. 111-120.
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BIOGRAPHICAL MEMOIRS
SELECTED BIBLIOGRAPHY
1923
Influences of light of very low intensity on phototropic reactions
of animals. I. Gen. Physiol., 6: 137-52.
1925
The electrical response to illumination of the eye in intact animals,
including the human subject; and in decerebrate preparations.
Am. J. Physiol., 73 :600-612.
1928
A quantitative and descriptive study of the electric response to il-
lumination of the arthropod eye. Am. J. Physiol., 83:466-83.
1930
The dark adaptation of the eye of Limulus, as manifested by its
electric response to illumination. I. Gen. Physiol., 13:379-89.
With C. H. Graham. Nerve impulses from single receptors in the
eye. J. Cell. Comp. Physiol., 1:277-95.
1934
Intensity and duration in the excitation of single photoreceptor
units. J. Cell. Comp. Physiol., 5:229-47.
With C. H. Graham. The response of single visual sense cells to
lights of different wave lengths. I. Gen. Physiol., 18:917-31.
1938
The discharge of impulses in the optic nerve of Pecten in response
to illumination of the eye. I Cell. Comp. Physiol., 11 :465-78.
The response to single optic nerve fibers of the vertebrate eye to
illumination of the retina. Am. J. Physiol., 121 :400-15.
1940
The receptive fields of optic nerve fibers. Am. l. Physiol.,130:690-
99.
The effects of spatial summation in the retina on the excitation of
the fibers of the optic nerve. Am. J. Physiol., 130:700-11.
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HALDAN KEFFER HARTLINE
211
The nerve messages in the fibers of the visual pathway. I. Opt. Soc.
Am., 30:229-47.
1941-1942
The neural mechanisms of vision. Harvey Lect., 37:39-68.
1947
With P. R. McDonald. Light and dark adaptation of single photo-
receptor elements in the eye of Limulus. ]. Cell. Comp. Physiol.,
30:225-54.
1949
Inhibition of activity of visual receptors by illuminating nearby ret-
inal areas in the Limulus eye. Fed. Proc., 8:69.
With H. G. Wagner and E. F. MacNichol. The peripheral origin of
nervous activity in the visual system. Cold Spring Harbor Symp.
Quant. Biol., 17: 125 -41.
1954
With F. Ratliff. Spatial summation of inhibitory influences in the
eye of Limulus (Abstr.~. Science, 120:781.
1956
With H. G. Wagner and F. Ratliff. Inhibition in the eye of the Lim-
ulus. ]. Gen. Physiol., 39:651-73.
1957
With F. Ratliff. Inhibitory interaction of receptor units in the eye
of Limulus. ]. Gen. Physiol., 40: 357-76.
1958
With F. Ratliff. Spatial summation of inhibitory influences in the
eye of Limulus, and the mutual interaction of receptor units.
J. Gen. Physiol., 41: 1049-66.
With F. Ratliff and W. H. Miller. Neural interaction in the eye and
the integration of receptor activity. Ann. N.Y. Acad. Sci.,
74:210-22.
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212
BIOGRAPHICAL MEMOIRS
1959
With F. Ratliff. The responses of Limulus optic nerve fibers to pat-
terns of illumination on the receptor mosaic. I. Gen. Physiol.,
42: 1241-55.
1961
With F. Ratliff and W. H. Miller. Inhibitory interaction in the retina
and its significance in vision. In: Nervous Inhibition, ed. E. Florey,
New York: Pergamon Press, pp. 141-84.
1963
With F. Ratliff and W. H. Miller. Spatial and temporal aspects of
retinal inhibitory interaction. I. Opt. Soc. Amer., 53: 110-20.
1966
With D. Lange and F. Ratliff. Inhibitory interaction in the retina:
Techniques of experimental and theoretical analysis. Ann. N.Y.
Acad. Sci., 128:955-71.
With F. Ratliff and D. Lange. The dynamics of lateral inhibition in
the compound eye of Limulus I . In: Proceedings of an International
Symposium on The Functional Organization of the Compound Eye, ed.
C. G. Bernhard, Oxford and New York: Pergamon Press, pp.
399-424.
With D. Lange and F. Ratliff. The dynamics of lateral inhibition in
the compound eye of Limulus II. In: Proceedings of an Interna-
tional Symposium on The Functional Organization of the Compound
Eye, ed. C. G. Bernhard, Oxford and New York: Pergamon
Press, pp. 425-49.
1967
With F. Ratliff, B. W. Knight, Jr., and J. Toyoda. Enhancement of
flicker by lateral inhibition. Science, 158:392-93.
1968
With F. Ratliff and D. Lange. Variability of interspike intervals in
optic nerve fibers of Limulus: Effect of light and dark adapta-
tion. Proc. Natl. Acad. Sci. USA, 60:464-69.
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HALDAN KEFFER HARTLINE
213
1969
Visual receptors and retinal interaction. In: Les Prix Nobel en 1967,
The Nobel Foundation, Stockholm, pp.242-59. Also in: Rocke-
feller Univ. Rev., 5(no. 5~:9-11, and Science, 164:270-78.
1972
With F. Ratliff. Inhibitory interaction in the retina of Limulus. In:
Handbook of Sensory Physiology, VII/2, Heidelberg: Springer-
Verlag, pp. 381-447.
1973
With N. Graham and F. Ratliff. Facilitation of inhibition in the
compound lateral eye of Limulus. Proc. Natl. Acad. Sci. USA,
70:894-98.
1974
With F. Ratliff, B. W. Knight, Jr., and F. A. Dodge, Jr. Fourier
analysis of dynamics of excitation and inhibition in the eye of
Limulus: Amplitude, phase, and distance. Vision Res., 14:1155-
68.
Studies on Excitation and Inhibition in the Retina A Collection of Papers
from the Laboratories of H. K. Hartline, ed. F. Ratliff, New York:
The Rockefeller University Press, 668 pp.
Representative terms from entire chapter:
optic nerve
