Age differences in noise and variability of isometric force production.

This study examined whether age-related improvements observed in the motor performance of children result from a reduction of noise in the output of the sensori-motor system. Children ages 6, 8, and 10 years and young adults (N = 48, 12 per group) performed continuous, constant isometric force contractions with the index finger at four different force levels with and without visual feedback. The results revealed that: (a) performance improved with increases in age, (b) the force output signal exhibited increased irregularity and a more broadband frequency profile with increases in age under conditions with feedback, and (c) there were no age differences in the irregularity of the force signal and smaller age differences in the frequency profiles under conditions without feedback. It is proposed that the age-related enhancements in performance throughout childhood are primarily due to a more appropriate mapping of the organization of the sensori-motor system to the task constraints rather than to reduction of system noise.

[1]  C. E. SHANNON,et al.  A mathematical theory of communication , 1948, MOCO.

[2]  S. S. Stevens,et al.  Handbook of experimental psychology , 1951 .

[3]  P. Fitts.  The information capacity of the human motor system in controlling the amplitude of movement. , 1954, Journal of experimental psychology.

[4]  N. A. Bernshteĭn.  The co-ordination and regulation of movements , 1967 .

[5]  K. Connolly,et al.  Mechanisms of Motor Skill Development , 1971 .

[6]  H. Zelaznik,et al.  Motor-output variability: a theory for the accuracy of rapid motor acts. , 1979, Psychological review.

[7]  D. Sugden,et al.  Movement Skill Development , 1985 .

[8]  K. Haywood.  Life Span Motor Development , 1986 .

[9]  S M Pincus,et al.  Approximate entropy as a measure of system complexity. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[10]  Lambert Schomaker,et al.  Neuromotor noise and poor handwriting in children. , 1993, Acta psychologica.

[11]  Karl M. Newell,et al.  Variability and Motor Control , 1993 .

[12]  A L Goldberger,et al.  Physiological time-series analysis: what does regularity quantify? , 1994, The American journal of physiology.

[13]  Isometric force regulation in children , 1995 .

[14]  G P Van Galen,et al.  Dysgraphia in children: lasting psychomotor deficiency or transient developmental delay? , 1997, Journal of experimental child psychology.

[15]  Peter C. M. Molenaar,et al.  Applications of nonlinear dynamics to developmental process modeling , 1998 .

[16]  Jan P. Piek,et al.  Motor Behavior and Human Skill: A Multidisciplinary Approach , 1998 .

[17]  Karl M. Newell,et al.  Degrees of freedom and the development of postural center of pressure profiles. , 1998 .

[18]  K. Newell,et al.  Noise, information transmission, and force variability. , 1999, Journal of experimental psychology. Human perception and performance.

[19]  J. R. Thomas,et al.  Movement substructures change as a function of practice in children and adults. , 2000, Journal of experimental child psychology.

[20]  K M Newell,et al.  Variability and Noise in Continuous Force Production , 2000, Journal of motor behavior.

[21]  Claude E. Shannon,et al.  A mathematical theory of communication , 1948, MOCO.