In a recent study on the pendulation of a small-sized humanoid robot (Lungarella & Berthouze, 2002a, b), we provided experimental evidence that starting with fewer degrees of freedom enables a more efficient exploration of the sensorimotor space during the acquisition of a task. The study came as support for the well-established framework of Bernstein (1967), namely that of an initial freezing of the distal degrees of freedom, followed by their progressive release and the exploitation of environmental and body dynamics. In this paper, we revisit our study by introducing a nonlinear coupling between environment and system. Under otherwise unchanged experimental conditions, we show that a single phase of freezing and subsequent freeing of degrees of freedom is not sufficient to achieve optimal performance, and instead, alternate freezing and freeing of degrees of freedom is required. The interest of this result is twofold: (1) it confirms the recent observation by Newell & Vaillancourt (2001) that Bernstein’s (1967) framework may be too narrow to account for real data; (2) it suggests that perturbations that push the system outside its postural stability or increase the task complexity may be the mechanism that triggers alternate freezing and freeing of degrees of freedom.
Arutyunyan, G. , Gurfinkel, V. , & Mirskii, M. (1969). Organization of movements on execution by man of an exact postural task . Biophysics, 14, 1162–1167 .
2.
Bernstein, N. (1967). The coordination and regulation of movements. Oxford: Pergamon .
3.
Bertenthal, B. , & Von Hofsten, C. (1998). Eye, hand, and trunk control: the foundation for manual development . Neuroscience and Biobehavioral Reviews, 22(4), 515–520 .
4.
Berthouze, L. , & Kuniyoshi, Y. (1998). Emergence of categorization of coordinated visual behavior through embodied interaction . Machine Learning, 31, 187–200 .
5.
Bjorklund, E. , & Green, B. (1992). The adaptive nature of cognitive immaturity . American Psychologist, 47(1), 46–54 .
6.
Bushnell, E. & Boudreau, J. (1993). Motor development in the mind: The potential role of motor abilities as a determinant of aspects of perceptual development . Child Development, 64, 1005–1021 .
7.
Elman, J. (1993). Learning and development in neural networks: The importance of starting small . Cognition, 48, 71–99 .
8.
Fitzhugh, R. (1961). Impulses and physiological states in theoretical models of nerve membrane . Biophyics H, 1, 445–456 .
9.
Goldfield, E. (1995). Emergent forms: Origins and early development of human action and perception. New York: Oxford University Press .
10.
Goldfield, E. , Kay, B. , & Warren, W. (1993). Infant bouncing: The assembly and tuning of an action system . Child Development, 64, 1128–1142 .
11.
Haehl, V. , Vardaxis, V. , & Ulrich, B. (2000). Learning to cruise: Bernstein’s theory applied to skill acquisition during infancy . Human Movement Science, 19, 685–715 .
12.
Hainline, L. (1998). How the visual system develops: Normal and abnormal development. In A. Slater , (Ed.), Perceptual development: Visual, auditory, and speech perception in infancy(pp. 5–50). Hove, Sussex: Psychology Press, Ltd.
13.
Haken, H. (1996). Principles of brain functioning. A synergetic approach to brain activity, behaviour, and cognition. Berlin: Springer Verlag .
14.
Hara, F. , & Pfeifer, R. (Eds.) (2003). Morpho-functional machines: The new species (designing embodied intelligence). Berlin: Springer-Verlag .
15.
Harris, P. (1983). Infant cognition. In M. M. Haith & J. J. Campos (Eds.). Handbook of child psychology: Infancy and developmental psychobiology, pp. 689–782. New York: Wiley .
16.
Jensen, J. , Thelen, E. , Ulrich, B. , Schneider, K. , & Zernicke, R. (1995). Adaptive dynamics of the leg movement patterns in human infants: Age-related differences in limb control . Journal of Motor Behavior, 27, 366–374 .
17.
Kay, B. (1988). The dimensionality of movement trajectories and the degrees of freedom problem: A tutorial . Human Movement Science, 7, 343–364 .
18.
Kelso, S. (1995). Dynamic patterns. Cambridge, MA: MIT Press .
19.
Ko, Y. , Challis, J. , & Newell, K. (2003). Learning to coordinate redundant degrees of freedom in a dynamic balance task . Human Movement Science, 22, 47–66 .
20.
Lungarella, M. & Berthouze, L. (2002a). Adaptivity through physical immaturity . In Proceedings of the 2nd International Workshop on Epigenetic Robotics, Lund University cognitive studies (Vol. 94, pp. 79–86 ). Lund. Lund University.
21.
Lungarella, M. , & Berthouze, L. (2002b). On the interplay between morphological, neural and environmental dynamics: A robotic case-study . Adaptive Behavior, 10(3/4), 223–241 .
22.
Lungarella, M. , & Berthouze, L. (2004). Robot bouncing: On the interaction between bodily and environmental dynamics. In F. Iida , R. Pfeifer , L. Steels , & Y. Kuniyoshi (Eds.). Berlin: Springer-Verlag .
23.
McDonald, P. , Emmerik, R. , & Newell, K. (1989). The effects of practice on limb kinematics in a throwing task . Journal of Motor Behavior, 21, 245–264 .
24.
Matsuoka, K. (1985). Sustained oscillations generated by mutually inhibiting neurons with adaptation . Biological Cybernetics, 52, 367–376 .
25.
Meltzoff, A. , & Moore, M. (1997). Explaining facial imitation: a theoretical model . Early Development and Parenting, 6, 179–192 .
26.
Metta, G. (2000). Babybot: A study on sensor-motor development. Unpublished Ph.D. Thesis, University of Genova.
27.
Mitra, S. , Amazeen, P. , & Turvey, M. (1998). Intermediate motor learning as decreasing active (dynamical) degrees of freedom . Human Movement Science, 17, 17–65 .
28.
Miyakoshi, S. , Yamakita, M. , & Furata, K. (1994). Juggling control using neural oscillators. In Proceedings of the 1994 IEEE/RSJ International Conference on Intelligent Robots and Systems(Vol. 2, pp. 1186–1193). Piscataway, NJ: IEEE .
29.
Murata, S. , Yoshida, E. , Kurokawa, H. , Tomita, K. , & Kokaji, S. (2001). Concept of self-reconfigurable modular robotic systems . Artificial Intelligence in Engineering, 15, 383–387 .
30.
Newell, K. , & Vaillancourt, D. (2001). Dimensional change in motor learning . Human Movement Science, 20, 695–715 .
31.
Newell, K. , & van Emmerik, R. (1989). The acquisition of coordination: Preliminary analysis of learning to write . Human Movement Science, 8, 17–32 .
32.
Ohgane, K. , Ei, S. , Kazutoshi, K. , & Ohtsuki, T. (2004). Emergence of adaptability to time delay in bipedal locomotion . Biological Cybernetics, 90(2), 125–132 .
33.
Piaget, J. (1953). The origins of intelligence. New York: Routledge .
34.
Piek, J. (2002). The role of variability in early development . Infant Behavior and Development, 156, 1–14 .
35.
Spencer, J. , & Thelen, E. (1999). A multiscale state analysis of adult motor learning . Experimental Brain Research, 128, 505–516 .
36.
Sporns, O. , & Edelman, G. (1993). Solving Bernstein’s problem: A proposal for the development of coordinated movement by selection . Child Development, 64, 960–981 .
37.
Taga, G. (1991). Self-organized control of bipedal locomotion by neural oscillators in unpredictable environments . Biological Cybernetics, 65, 147–159 .
38.
Taga, G. (1994). Emergence of bipedal locomotion through entrainment among the neuro-musculo-skeletal system and environment . Physica D, 75, 190–208 .
39.
Taga, G. (1997). Freezing and freeing degrees of freedom in a model neuro musculo skeletal systems for the development of locomotion . In Proceedings of the 16th International Society of Biomechanics Congress(p. 47-47 ).
40.
Thelen, E. , Fisher, D. , & Ridley-Johnson (1984). The relationship between physical growth and a newborn reflex . Infant Behavior and Development, 7, 479–493 .
41.
Thelen, E. , & Smith, L. (1994). A dynamic systems approach to the development of cognition and action. Cambridge, MA: MIT Press .
42.
Turkewitz, G. , & Kenny, P. (1982). Limitations on input as a basis for neural organization and perceptual development: A preliminary theoretical statement . Developmental Psychology, 15, 357–368 .
43.
Vereijken, B. , van Emmerik, R. , Whiting, H. , & Newell, K. (1992). Free(z)ing degrees of freedom in skill acquisition . Journal of Motor Behavior, 24, 133–142 .
44.
Williamson, M. (1998). Neural control of rhythmic arm movements . Neural Networks, 11(7/8), 1379–1394 .
45.
Wolpert, D. , Doya, K. , & Kawato, M. (2003). A unifying computational framework for motor control and social interaction . Philosophical Transactions of the Royal Society of London B, 358, 593–602 .
46.
Zernicke, R. , & Schneider, K. (1993). Biomechanics and developmental neuromotor control . Child Development, 64, 982–1004 .
