Editor's note: Roger Sperry, Nobel prize-winning physiological psychologist,
is remembered here by one of his early students and followers, Robert W. Doty.
Sperry, an APS Charter Fellow, is perhaps best known for his pioneering
split-brain research and his work on neurospecificity which won him, among
other awards, the Nobel Prize for Medicine (1981) and the National Medal of
Science (1990). One of a handful of psychologists (i.e., sensory physiologist
Georg von Békésy and APS Charter Fellow Herbert Simon) to have received the
Nobel Prize, Sperry's research has had a profound effect on the progress of
physiological psychology specifically and brain science generally. Insights
are provided into Sperry s later endeavors and philosophical interests, in the
January 1990 Observer, but Robert Doty presents here a personal remembrance of
this scientific giant and an elaboration on Sperry s most recent philosophical
writings. As a graduate student, Doty took Sperry s neuroanatomy course in
the late 1940s, and Sperry served as a guest examiner on Doty s dissertation
defense committee.

On Sunday, 17 April 1994, Roger Sperry obtained surcease from quickening
neurological loss of motor control that had been insidiously crippling him for
almost three decades. For this exceptional athlete, avid fisherman, savvy
fossil hunter of the wilder American West, peerless surgeon, and talented
sculptor his affliction must have been particularly difficult to bear. He did
so with quiet courage, remarking toward the end in his typically gentle humor
that he was beginning to fear some encroachment upon more than his motor
system. But, there was not the slightest evidence of this in his writings or
correspondence. Mercifully, the final thrust was from cardiac arrest rather
than failure of brainstem motoneurons. The accompanying photo, provided by
one of his former students, Marge Scott Scherick, shows him in sturdier
circumstance in the late 1950s.
He had an almost uncanny knack of selecting problems of fundamental
import, and then devising ingenious experiments to yield clear, definitive
answers. He revolutionized two fields of neuroscience, showing: (a) that
neuronal connections are formed and maintained with a high degree of
precision, presumably via chemical interchange; and (b) that each cerebral
hemisphere is potentially an independent cognitive mechanism. An even greater
societal impact, however, may yet flow from his philosophical reworking of the
mind-brain problem, promulgating a directly simple concept that could
reverberate throughout human behavior.

naught of his early years. It is apparent that his talents were well-nurtured
at Oberlin College, where in 1935 he received his Bachelors degree in English,
and then continued for a Masters degree in psychology two years later. His
first major philosophical contribution (1952), arguing the primacy of movement
over perception as a guide to comprehending the mind-brain relationship,
acknowledges his indebtedness to his young professor of psychology at Oberlin,
R. H. Stetson.

Chicago with Paul Weiss, a major figure in zoology. From a long series of
ingenious experiments Weiss had come to propose a physiologically peculiar
theory of resonance between a muscle and its central control circuitry (see
Weiss, 1952). While Weiss facts remain largely unchallenged, Sperry s
doctoral thesis and later work ultimately forced a complete re-evaluation of
Weiss interpretation. This process was perhaps crowned by Sperry s
dramatically brilliant experiments on newts with rotated eyes. The newt
forever reacted as though the world were upside down, even when the optic
fibers from the rotated eye were allowed to reform their central connections.
His thesis work on cross-innervation and muscle transposition in rats had, in
addition, also put an end to almost a century of nonsense about facile
reorganization of the central nervous system consequent to changing peripheral
connections, as he meticulously set forth in his 1945 review.

that incomparable shaker of the temple of neuroscience, Karl Lashley, as a
postdoctoral mentor. On his fellowship at Harvard and the Yerkes primate
laboratories, then at Orange Park, Florida, he attacked another dubious
concept of neuronal integration, that electrical fields or waves are critical
in neocortical processes. The approach was to place multiple insulating
elements (mica plates or subpial scarring) or short-circuiting elements
(tantalum pins) into the cortex, and then examine the function subserved by
the affected system. The effects were essentially nil, and in sum adumbrated
the now well-supported idea that the neocortical feltwork is organized
vertically, into overlapping and interdigitating columns of neurons.

investigating the puzzle of the corpus callosum. Although there had been
sporadic work, reported in German and Russian, showing behavioral consequences
in animals of severing this massive interconnection between the two
hemispheres, observations at the University of Rochester in the early 1940s by
two skilled psychologists, A. J. Akelaitis and K. U. Smith, on epileptic
patients with large but varying transections of the callosum, had failed to
find significant deficit. This can best be attributed to the incompleteness
of many of the transections as well as to the inadequacy of their tests; but
the fact that such patients seemed to display normal mentality and bimanual
dexterity (e.g., playing the piano), provided a startling challenge to
understanding what might be going on in the brain. The clever invention of
the split-brain preparation, severing the optic chiasm to channel all visual
input to one or the other hemisphere, followed by transection of various
interhemispheric connections, allowed thorough and decisive testing of the
latter pathways in conveying visual information from one half of the brain to
the other. Exploitation of this procedure by Sperry and his students rapidly
led to appreciation of the manifold roles of the interhemispheric commissures
in behavior.

revising both concepts and techniques, that made possible the unprecedented
insights into functions of the individual hemispheres in man. The
shortcomings of the University of Rochester experiments could now be avoided
when human patients again treated largely successfully with callosotomy (and
transection of the anterior commissure) for intractable epilepsy by
neurosurgeons Phillip J. Vogel and Joseph E. Bogen became available for
testing in the Sperry laboratory. His proof that human consciousness could
reside in the linguistically retarded right hemisphere was on an intellectual
par with the Copernican and Darwinian revelations that helped define man s
place in nature; for it is apparent from the work of Sperry and his colleagues
that each human brain has, potentially, two vast networks capable of human
experience a fact cogently verified in instances of left hemispherectomy.

profound philosophical enigmas, and Sperry, true to his 1952 interest in the
mind/brain dilemma, pursued and wrote widely on the meaning of these
discoveries. Here, again, he has taken a revolutionary step, although now in
the realm of philosophy proof will be incomparably more elusive. The
deceptively simplistic nature of his proposal is that the mind, wholly a
creation of the brain, works back upon the brain pari passu, and therefore
controls the neuronal outcome.

ineluctable culmination of cascading neuronal connections ascending causally
from Brownian motion to neuronal populations. Such upward evolution, from
atomic level to neurons, would inescapably induce a mere robotic mind, driven
by the chemistry of its past and the chance though intricate fluctuations of
the moment; whereas if the causal chain proceeds from the highest, mental
level downward, the integrated output of the neuronal action incorporates, and
is controlled by, the conscious decision so familiar to each human being.
This immediately gives new meaning to consciousness, and returns
responsibility to the mind as distinct from ionic whim. Materialists will
no doubt bridle at the thought, contradicting as it does some three centuries
of effort to depict mental experience solely in terms of molecular-neuronal
events; yet there is nothing immaterial in the concept, only the supposition
that the operation of certain vast neuronal networks transcends their
molecular description. In a manuscript to be published posthumously, Sperry
renders the choice between upward versus downward control with his usual
ingenuity: (a) given that the brain is the sine qua non of mental experience,
and (b) that ignorance is essentially total as to how this comes about, it is
not only more logical to assume that the mental aspect is capable of
controlling the entity (i.e., the neuronal network), it is socially far more
constructive than accepting, willy nilly, arguments for the robotic mind in
the absence of decisive evidence either way! It bears emphasis that nothing
psychic is implied in these ideas, Sperry having already made the astutely
devastating criticism of such pseudoscience; were paranormal communication to
exist, where better to expect it than between the two hemispheres of patients
lacking the corpus callosum!?

Psychological Society, was repeatedly honored for his contributions: the
Passano Award, 1973; the Lashley Award of the American Philosophical Society,
1976; the Wolf Prize in Medicine, 1979; and the Lasker Medical Research Award,
1979; the Nobel Prize in Physiology and Medicine, 1981, which he shared with
David H. Hubel and Torsten N. Wiesel; and the National Medal of Science, 1989.
Of equal value to him was the keen enthusiasm of his many students and
colleagues, so richly instantiated in the volume edited by Colwyn Trevarthen
(1990); and yet another Festschrift is in the making; it was to have honored
his 81st birthday.

of a life so wonderfully and courageously lived.