BJMB
Brazilian Journal of Motor Behavior
Special issue:
“In memory of Michael Turvey”
!
Feldman
2023
VOL.17
N.6
294 of 296
Biological Movements as Objects of Natural Science (In memory of Michael Turvey,
February 14, 1942 - August 12, 2023)
ANATOL G. FELDMAN
1
1
Department of Neuroscience, University of Montreal, and Center for Interdisciplinary Research in Rehabilitation (CRIR), Canada
Correspondence to:!Anatol Feldman, PhD, DSci
Neuroscience, University of Montreal, Canada
email: feldman@med.umontreal.ca
anatol.g.feldman@umontreal.ca
https://doi.org/10.20338/bjmb.v17i6.413
ABBREVIATIONS
EP Equilibrium-point
FR Frame of reference
λ Lambda
PUBLICATION DATA
Received 27 11 2023
Accepted 15 12 2023
Published 22 12 2023
ABSTRACT
Michael Turvey was a great scientist, encyclopedist, fine lecturer, and, together with his wife
and colleague Claudia Carello a wonderful friend of many. Mike Turvey was able to educate
the next generation of students and influence the thinking of many outstanding researchers by
focusing on a multidisciplinary approach to ecological psychology in which organisms directly
perceive sensory stimuli and evaluate them depending on actions they can accomplish in the
environment (Gibson 1968). This, “affordance principle” is applied to all biological kingdoms
from a single cell amoeba to multi-celled organisms. Some other essential ideas in behavioral
neuroscience advanced by Turvey are considered.
KEYWORDS: Behavioral neuroscience | Ecological framework | Action-perception coupling |
Equilibrium-point hypothesis | Referent body configuration | Synergy | Parametric control |
Neural patterns | Spatial frames
INTRODUCTION
Michael Turvey was a great scientist, encyclopedist, fine lecturer, and, together with his wife and colleague Claudia Carello a
wonderful friend of many. Mike Turvey was able to educate the next generation of students and influence the thinking of many
outstanding researchers (e.g., William Warren, Elliot Saltzman, Scott Kelso, Mark Latash and many others), by focusing on a
multidisciplinary approach to ecological psychology in which organisms directly perceive sensory stimuli and evaluate them depending on
actions they can accomplish in the environment (Gibson 1968). This, “affordance principle” is applied to all biological kingdoms from a
single cell amoeba to multi-celled organisms.
I first became familiar with the work of Turvey’s group in 1980 by reading the paper by P.N. Kugler, J.A.S. Kelso, M.T. Turvey
entitled “On the concept of coordinative structures as dissipative structures: I. Theoretical lines of convergence.” At the time I was a PhD
student in the Faculty of Physics of Living Systems at the Moscow Institute of Physics and Technology. The paper by Kugler et al.
implied that it is important to consider action and perception in the context of natural sciences, especially, the dynamic systems theory. In
addition, the paper appealed to me since I considered it as a step in the understanding of the concept of synergy applied to the redundant
degrees of freedom in neuromuscular systems, as suggested by Nicolai Bernstein (1967), whose work was considered with much respect
by Mike Turvey. Later, by reading Mike Turvey’s work and communicating with him personally, I was impressed by his ability to consider
action and perception in the broad context of natural laws and principles applied to all biological creatures, which deeply influenced and
continues to influence my thinking about action and perception. This approach to biological phenomena is well reflected in his text
“Lectures on Perception. An Ecological Perspective (2019)”. I regularly consult these lectures during my research.
I would like to also emphasise an important role the writings of Mike Turvey played in familiarizing Western researchers with the
work on behavioural neuroscience conducted in Russia. Specifically, approximately in 1959, a great mathematician, Israel Gelfand
organized the Moscow Biological School with the purpose of attracting specialists in biology, mathematics, physics, engineering and
biochemistry to join in what is now known as a multidisciplinary approach to biology in general and to the neural control of movement in
particular (Berkinblit and Latash 2005; Chapter 1 in Feldman 2015). Nikolai Bernstein gave a cycle of lectures on motor control for this
group and his ideas were well appreciated. Before I joined this school in 1963, scientists at the lab had made many achievements. For
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Brazilian(Journal(of(Motor(Behavior(
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Feldman
2023
VOL.17
N.6
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Special issue:
“In memory of Michael Turvey”
example, my colleagues, Grisha Orlovsky, Feodor Severin and Mark Shik had discovered a small neural area in the brain stem, called
the mesencephalic locomotor area, which when continuously electrically stimulated at a certain frequency, compelled the intact and even
decerebrated cat to walk and run. By using this technique, neuronal mechanisms of locomotion were studied in our lab and later, in many
other labs abroad (summarized in Shik and Orlovsky 1976; Grillner 1975; Rossignol et al. 2006). I contributed to these achievements by
formulating the equilibrium-point (EP) hypothesis in 1965. The first description of the EP hypothesis was initially published in Russian and
badly translated into English in J Biophysics. Not surprisingly, the EP hypothesis was poorly understood, and it was necessary to clarify
its essence, which I did in a paper edited by Scott Kelso (Feldman 1986). In the totalitarian regime of Russia, I was locked beyond the
iron curtain. Like many other scientists in Russia, I was not allowed to travel to the West and to communicate or work with scientists
abroad. After about 21 years, I finally obtained permission to travel abroad and was able to meet Mike Turvey. He told me that he gave a
cycle of lectures at MIT about the EP hypothesis and our group in Moscow. In so doing, he strengthened the scientific bridge between our
groups in Moscow and in the West, which I especially appreciated since he removed artificial obstacles to scientific communications
created by the totalitarian regime in Russia.
I will consider some, far from complete ideas of Mike Turvey and his group that especially influenced my thinking about action
and perception. One of them is the notion of dualism in the behavior of biological systems- that their behavior should be considered
together with the environments to which they are usually well adapted. In consonance with this notion, the EP concept symbolises the
control of balance between muscle forces and forces acting in the environment, particularly gravitational forces. In the simplest case, the
environment is represented by the external loads with which muscles and body segments interact. While discussing the EP hypothesis
with me, Mike noted that the lambda (λ), the threshold at which motoneurons begin to be recruited or de-recruited, is a parameter that is
“scalable” across different hierarchical levels of neural control. To clarify, he implied that the threshold of recruitment can refer not only to
motoneurons of a single muscle but globally, to the entire set of muscles of the body by controlling them as a coherent unit without
redundancy problems. I readily accepted this idea, and subsequently expressed it in the idea of the referent body configuration, i.e.,
specific body posture at which numerous muscles of the body can be at relative rest (“silent”) but can be activated depending on the
deflection of the actual body posture, Q, from the threshold posture R. The idea that muscle activation depends on the two variables
implied a dualism in the control of multiple muscles. In addition, it implied that all possible body postures (configurations) can be
considered as comprising a spatial frame of reference (FR) or system of coordinates in which the referent body configuration plays the
role of the origin point such that the distance of other body postures, Q, from the R defines how muscles of the body are activated. This
concept is also consonant with the idea of Turvey (2019) that action and perception are produced in certain, spatial FRs. The suggestion
that redundancy problems are solved through the interaction of the organism with the environment also followed from the notion that
referent control is also a form of parametric control (Chap. 2, in Feldman 2015). Thereby, motor actions represent manifestations of
physical laws parameterized by the nervous system thus influencing the interaction between the organism and the environment. Once
parameters are specified, the nervous system takes advantage of physical laws by allowing them to produce an unique motor action. This
process manifests in the neural selection of a specific action pattern from many other possible patterns (see Fowler and Turvey 1978).
Neural selection of action patterns is comparable with the natural selection of species in evolution, although neural selection of action
patterns is produced during a much shorter time scale. Thus, based on personal communications with Mike Turvey, I proceeded with
advancing the EP hypothesis to the referent control theory of action and perception (Feldman 2015). Indeed, other researchers will also
find that Turvey’s publications, and particularly “Lectures on Perception” are outstanding contributions to behavioral neuroscience.
Let the memory of his brilliant mind and beautiful soul be a blessing for those who knew him and his work.
REFERENCES
1. Berkinblit M.B. & Latash M.L. (2005) Introduction. In: Forty Years of Equilibrium-point Hypothesis. M.F. Levin (ed) Tristar Printing INC, Lachine, QC,
p 1-2.
2. Bernstein N.A. (1967) Co-ordination and Regulation of Movement. Pergamon, Oxford.
3. Feldman A.G. (1986) Once more on the equilibrium-point hypothesis (lambda model). J Mot Beh 18, 17-54.
4. Kugler P.N., Kelso J.A.S. & Turvey M.T. (1980) On the concept of coordinative structures as dissipative structures: I. Theoretical lines of
convergence. In: Tutorials in Motor Behavior, G. E. Stelmach and J. Requin (eds) North-Holland Publishing Company.
5. Gibson J.J. (1968) Senses Considered as Perceptual Systems. George Allen and Unwin LTD, London, 336 pp.
6. Turvey M.T. (2019) Lectures on Perception, An Ecological Perspective. Routledge, Taylor and Francis Group, NY, London, 432 pp.
7. Feldman A.G. (2015) Referent Control of Action and Perception. Challenging Conventional Theories in Behavioral Neuroscience. Springer, NY, 242
pp.
8. Grillner S. (1975) Locomotion in vertebrates: Control mechanisms and reflex interactions. Physiol Rev 55(2) 247-304. doi:
10.1152/physrev.1975.55.2.247
9. Fowler C.A. & Turvey M.T. (1978) Skill acquisition, an event approach with special reference to searching for the optimum of a function of several
variables. In: Information Processing in Motor Control and Learning. G.E. Stelmach (ed) Academic, NY, p 1-40.
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Special issue:
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10. Rossignol S., Dubuc R. & Gossard J.P. (2006) Dynamic sensorimotor interactions in locomotion. Phys Rev 86(1) 89-154. doi:
10.1152/physrev.00028.2005
11. Shik M.L. & Orlovsky G.N. (1976) Neurophysiology of locomotor automatism. Phys Rev, 53(3) 465-501. doi: 10.1152/physrev.1976.56.3.465
Citation: Feldman AG. (2023).!Biological Movements as Objects of Natural Science (In memory of Michael Turvey, February 14, 1942 - August 12, 2023). Brazilian Journal
of Motor Behavior, 17(6):294-296.
Editor-in-chief: Dr Fabio Augusto Barbieri - São Paulo State University (UNESP), Bauru, SP, Brazil. !
Associate editors: Dr José Angelo Barela - São Paulo State University (UNESP), Rio Claro, SP, Brazil; Dr Natalia Madalena Rinaldi - Federal University of Espírito Santo
(UFES), Vitória, ES, Brazil; Dr Renato de Moraes – University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
Guest editor: Dr Vitor Leandro da Silva Profeta - University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.!
Copyright:© 2023 Feldman and BJMB. This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives 4.0
International License which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Nothing to report.
Competing interests: The authors have declared that no competing interests exist.
DOI:!https://doi.org/10.20338/bjmb.v17i6.413