Given the recent discussion on Hebb's place in history, I
thought the recent article would be of interest.
Ken
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Date: Mon, 15 Nov 1999 15:17:18 -0500
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Subject: psyc.99.10.045.lashley-hebb.2.robinson (271 lines)
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psycoloquy.99.10.045.lashley-hebb.2.robinson Mon Nov 15 1999
ISSN 1055-0143 (11 paragraphs, 5 references, 265 lines)
PSYCOLOQUY is sponsored by the American Psychological Association (APA)
Copyright 1999 Daniel N. Robinson
THE SNARK IS STILL A BOOJUM
Book Review of Orbach on Lashley-Hebb
Daniel N. Robinson
Distinguished Research Professor & Professor of Psychology
Georgetown University
Washington, D. C. 20057
[EMAIL PROTECTED]
and
Visiting Professor of Psychology
Brigham Young University
Provo, Utah 84602
ABSTRACT: This "living history" of the neuropsychological thinking
of Lashley and Hebb provides the reader with useful, instructive
and suggestive details on matters of priority, influence and
perspective. Orbach's own expert knowledge of neuropsychology
serves the reader well as the author assesses contemporary thinking
in the brain sciences in light of the issues that so engaged the
energies of Lashley and Hebb. But the greater service is bringing
to print a number of Lashley's own lectures and essays (chiefly his
Vanuxem Lectures) previously available only in special
collections. Even the several previously published articles take
on renewed importance as a result of Orbach's discussion and
critical appraisals of contemporary thought.
1. Jack Orbach (1998, 1999) has made an important contribution to
contemporary neurocognitive science not only in making available
Lashley's important and still timely Vanuxem Lectures, but by situating
the Lashley-Hebb neuropsychologies within a matrix of theoretical and
conceptual issues that remains central to the project of the "brain
sciences". For the historian of science, there are informative
"first-hand" discussions of questions of priority on such matters as
neural plasticity, reverberatory circuits, cell assemblies, etc. In
addition, Orbach brings the contemporary reader into the lively,
somewhat combative and competitive relationship between these two
luminaries of twentieth century thought in neuropsychology. The
author's own personal associations and experiences, combined with his
expert knowledge of neuropsychology, permit him to translate the bones
of contention into terms that still inform and test contemporary
theoretical and conceptual predilections.
2. Just under 400 pages, the volume is divided into two main parts,
with Part Two presenting Lashley's Vanuxem Lectures and a number of
carefully selected previously published essays. It is in Part One that
Orbach discusses matters of theoretical attachment and priority, and
the current and longer range implications of Hebb's and Lashley's
positions. It is useful to pause to consider this matter of priority.
3. Orbach's Prologue begins with a passage from Lashley's final public
lecture, given in 1957 at the University of Rochester; a lecture
remarkable for what is never mentioned; viz., Hebb's (1949) by then
celebrated and widely discussed "The Organization of Behavior" and its
central theoretical concept of "cell assemblies". Orbach is of the view
that Lashley had no need to comment on this, for Lashley years earlier
had advanced most of the ideas that gave Hebb's work weight and
promise: "...non-sensory control of behavor, the central autonomous
process, mechanisms of attention, and the importance of Lorente de No's
reverberatory circuit" (Orbach, 1998; p. xii). Matters of priority,
however, tend to be elusive, especially in scientific realms of inquiry
that develop progressively, bit by bit, as it were. One does not
deprecate the contributions of Lorente de No or Lashley and Hebb in
noting the fairly long and robust pedigree behind each of the central
ideas discussed by Orbach. Certainly any historical account, even a
quite general one, would include the experimental and technical
writings of David Hartley, Robert Whytt, Marshall Hall, Alexander Bain
(though see Milner's comments on p. 16), and David Ferrier, not only as
important precursors but even as perhaps surprisingly detailed
anticipations of the theories under consideration; and this cites only
the British contingent.
4. The point here is not one of priority or, alas, pedantry! Rather, in
light of the historical persistence and repetition of such notions, and
in light of the significant technical progress and enlargement of the
data-base taking place over this same span of time, one must ask
whether these very notions are, at base, "theoretical" in the fuller
scientific sense of the term. This issue is clearly too large for the
space reserved here. It is sufficient to point out that neither Orbach
nor Lashley and Hebb can be found considering this possibility. At the
level of anatomical elaboration and dynamics, the vertebrate nervous
system is at once the theoretician's dream and nightmare: It
instantiates any pet theory, for it instantiates all of them.
5. In the first chapter ("Setting the Stage"), Orbach rehearses the
influence of Lashley's teacher, John B. Watson, on dampening enthusiasm
for physiological theorizing: Watson's S-R psychology, which seemed to
leave out the brain. Of course, Watson's confidence in his behaviorism
was fortified to some extent by Pavlov's research and theory and,
though Watson resisted the notion of gremlins digging associational
grooves in the brain, he was not indifferent to the relationship
between a behavioral and a physiological psychology. By the same token,
Lashley was not uncritical in assessing the mechanisitic neurobiology
of the same period (Orbach, 1998; p. 133). If there was a more or less
official declaration of independence, it would come later, in the final
pages of Skinner's Behavior of Organisms (1938), which defends the
project of a "purely descriptive" science of behavior that need not
await enlightenment from the physiology laboratory. By then, of course,
Lashley's overall project was in full swing and could number among its
successfully vanquished critics a Skinnerian behaviorism that had yet
to be born. Orbach offers Lashley's specific comment on this in a 1952
address excerpted on pp. 111-112. What Lashley understood so fully is
that a mechanisitic Pavlovian neuropsychology, like a Skinnerian
descriptive behaviorism, becomes ever less credible the more broadly
one samples from the rich and various realms of behavior.
6. Lashley and, years later, his student Hebb, would both find in
Lorente de No's "reverberatory circuit," the means by which the past
could be preserved within the central nervous system. Once established,
such circuits give the brain autonomous activities no longer requiring
external stimulation. "Mechanism" now gives way to dynamism and to
what, in the idiom of a later time, would be seen as a self-organising
system. The famous search for the engram would end less in failure than
in a perspectival shift: It isn't anywhere, for it is more or less
everywhere that duplicated or resonant processes are generated. The
search itself may have begun as early as Lashley's sixteenth year when,
for 25 cents an hour, he cleaned the basement of the Zoology Department
at the University of West Virginia and became transfixed by Golgi
series for the frog brain (Orbach, 1998; p. 115). Orbach reminds
readers that Lashley's focus on the cerebral cortex was responsible for
his skepticism and that he "might well be astonished to learn that
Richard Thompson has proposed the cerebellum as the site for memory
traces of the classically conditioned response" (p. 24). Yet, so much
in Lashley resists place-theories that it is less than certain "traces"
would astonish him more if found in cerebellum than, for that matter,
in the Islets of Langerhans.
7. In the matter of reverberatory circuits and "field theories", it
appears that Lashley remained wedded to the notion that cell-to-cell
activity, only after some other mode of integration, may come to
comprise a "field" (Orbach, 1998; pp. 29-30). What is missing in the
account oddly for an "instinct" theorist is an appreciation of the
degree of "pre-wired" cell-to-cell activity (which is to say
pre-established "fields") that must already determine (because they
are) the cell-to-cell complex influences and dependencies. If there is
an important distinction to be made here -- for Lashley was surely a
"field" theorist -- it has to do with a system whose "tuning" is in
place for there to be resonant circuits. By 1949 Lashley is still
tentative on the point, noting only that "evidence is accumulating" in
favor of the view that "organization within integrative centers...is
entirely different from (a) simple chain conduction" (Orbach, 1999; p.
186). Yet, even here, there seems to be a sensed difference between
"organization" and what might be understood as richly rather than
simply chained influences. (Thus, if stubbornly, I am inclined to
believe that Lashley "thinks cell-to-cell activity is different from,
rather than the source of, the field"; Orbach, 1999, p. 29).
8. Regarding his credentials as an instinct theorist, Lashley's
scientific and, shame to be told, racist ideas are both given full and
fair treatment by Orbach. His constructive writings and teaching on the
subject would influence such of his students as Frank Beach; his
deplorable prejudices, one hopes, influenced no one. Both he and Hebb
left ample room for instinctual processes even at the level of
associative learning, but neither filled the room with much beyond
granny's furniture, as refinished and wonderfully arranged by Darwin,
George Romanes, Conwy Lloyd Morgan, et al. For Hebb, "instinct and
intelligence differ in complexity of mechanism" (p. 39), a position at
once startling and revealing when taken by someone possessed of so high
an intelligence. Nor was Lashley's own understanding of intelligence
(Orbach, 1998; p. 78) relevantly different, at least as this
understanding would be developed in "Brain Mechanisms and Intelligence"
(1929). If Hebb found no more to the matter than a "complexity of
mechanism", Lashley was content that "it" was genetically fixed and
sampled validly by such chores as maze-learning. These and kindred
conclusions from Lashley and from Hebb reveal the source of their
(generously bequeathed) confidence in the range and reach of the brain
sciences; a range and reach claiming to get hold of emotion,
motivation, learning, memory, intelligence, creativity. Such passages
could have (and, indeed, did) come from Pierre Cabanis a century and a
half earlier; the Cabanis described by Carlyle as one who, "goes
through a world of wonder unwonderingly".
9. Especially interesting (for they still defy easy explanation in
mechanistic terms) are Lashley's famous studies of recovery of
function, of the use of pathways non-functional during learning, etc.
This is fully developed in the Vanuxem Lectures with which Part Two of
the volume begins. It is here that the concept of equipotentiality
grows out of imaginative research which, at the same time, raises
doubts about the adequacy of "synaptic resistance" theories of learning
and memory. As for the research itself, Lashley appreciated (even if he
was not self-consciously guided by) William James's psychologist's
fallacy. What one is prepared to say about the powers and achievements
of human beings and non-human animals depends crucially on how one goes
about sampling these very powers and achievements.
10. Lashley admits that for nearly a decade he and any number of
scientists were convinced that dogs and rats were nearly blind, until
the right sort of assessments were introduced (Orbach, 1998; pp.
177-178). But if thus awakened from one dogmatic slumber, he seems
(along with so many of his colleagues and scientific descendents) to
drop off into another. The mammalian nervous system did not evolve
under the selection pressures of the Psychology laboratory. Less was it
expected to reveal itself clearly only after having been macerated by
the scalpel and the anatomical blowpipe. If such a laboratory as
recently as 1920 led thoughtful persons to regard dogs and rats as
nearly blind, one can only wonder how it continues to shape thinking.
If one would come to grips with the complexity and plasticity of
adaptive behavior, one wisely goes to where that behavior is shaped and
tested daily, hourly, even by the minute. And when one reaches that
privileged position of the observer of nature, one is careful to
disturb as little as possible, and surely as little of the brain and
body as possible. Here the confluence of ethical high-mindedness and
scientific aspiration is perhaps most complete. But nowhere in this
otherwise fine and instructive volume are such utterly pivotal issues
given the attention they should have demanded of Lashley, Hebb and
Orbach himself.
11. If that one pivotal question is essentially ignored, it is not
because Lashley and Hebb were timid about addressing each and every
quaestio vexata. Consider only Lashley's heroic entrance into that
enduring fray, the mind/body problem (Orbach, 1998; pp. 327-378). The
careful reader will find in these pages as much analytical rigor and
substantive use of clinical and experimental findings as any
contemporary philosopher or scientist, of materialist persuasion, has
offered. In a word, there is a neurophilosophy here rather more
informed and informing than current popular ("pop"?) versions. Lashley,
of whom it may be said that he had a vocation before the age of
careers, had read Haeckel and Huxley, James, Wundt, Titchener and
McDougall, Sherrington and Pavlov; he read those who had given
definition to the scientific side of the dispute. But he had also read
the philosophers, the ethologists, the poets, even Kant! If, in the
end, he concluded that "mind has no attributes other than its
organization" and that "this particular organization by which alone
mind can be defined is the organization of the activities of the brain"
(Orbach, 1998; p. 329), he reached this conclusion by default.
Alternative theories he judged to be either groundless or weaker or
less in concert with the laboratory and the clinic. That he misreads
Descartes (e.g., p. 332) seems by now to be an entrance-requirement for
the College of Positivistic Cognitive Neuroscience: "I eat, therefore I
am", indeed! (p. 333). And he certainly lived long enough for his own
reflections (pp. 333-334) on the "privacy of the mental" to derive more
rigorous support from Wittgenstein. But against the pardonable lacunae
and occasional howler can be projected arguments and understandings at
once forceful and original. In an age in which the "brain sciences" are
serving up so many volumes best described as "thick but thin", it is
gratifying to have one that is "thin but thick".
REFERENCES
Hebb, D. O. (1949) The Organization of Behavior: a Neuropsychological
Theory. New York: Wiley.
Lashley, K. S. (1929) Brain mechanisms and intelligence: A
quantitative study of injuries to the brain. New York: Dover.
Orbach, J. (1998) (Ed.) The Neuropsychological Theories of Lashley and
Hebb. University Press of America
Orbach, J. (1999) Precis of: The Neuropsychological Theories of Lashley
and Hebb. PSYCOLOQUY 10(23).
ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/
psyc.99.10.029.lashley-hebb.1.orbach
http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.29
Skinner, B. F. 1938. The behavior of organisms. New York:
Appleton-Century-Crofts.
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----------------------
Kenneth M. Steele [EMAIL PROTECTED]
Associate Professor
Dept. of Psychology
Appalachian State University
Boone, NC 28608
USA
