The relationship between expected magnitude and produced magnitude in production of force and running time

Abstract

The purpose of this study was to examine the relationship between expected magnitude and produced magnitude in producing handgrip force and running time by using the method of magnitude production from the view point of psychophysics, and to investigate the directionality and the consistency of production errors by analysing the constant error (CE) and the ratio of variable error (RVE). The standard force and time (modulus), designed as 100% grade, were handgrip force and time of 20 meter-run under the condition of maximum exertion. The instructed grades were l0, 30, 50, 70,and 90% to maximum. The main resu1ts are summarised as follows: 1) A produced magnitude grew ad a power function of an expected magnitude with the exponent of 1.83 for handgrip force and 1.72 for running time. There were no significant differences between males and females with respect to the exponent of the function in both tasks. 2) On handgrip force, the central tendency as a central point around 50% grade, where smaller force (10% and 30%) tended to be overshot and larger force (70% and 90%) tended to be undershot, was recognized on the CE. On running time, the CE was characterized by overshooting in all conditions, while the tendency of overshooting significantly increased as the instructed grade decreased. There were no significant differences between males and females on the CE for both tasks. 3) The RVE for the instructed grade of 10% was significantly higher than that for each of the others on both handgrip force and running time. There were no significant differences between males and females on the RVE for both tasks.