FILTER CHARACTERISTICS OF FINE-SURFACE-TEXTURE DISCRIMINATION IN HUMAN TACTILE PERCEPTION

点击翻译按钮获取中文摘要

Miyaoka et al. proposed "amplitude-information hypothesis" for the mechanisms of fine-surface-texture discrimination in human tactile perception. The tactile information-processing system has low-pass-filter characteristics and the amplitude information only passed through the filter was used for the discrimination tasks. The Purpose of this study was to investigate the low-pass filter characteristics.1.A mathematical model was produced to show what was observed if the tactile system had the low-pass filter. In roughness discrimination tasks of diffraction gratings, the mathematical model predicted that the psychometric functions of discrimination tasks showed specific patterns.2.In an active-touch experiment, diffraction gratings were used as stimuli. Their wavelengths were from 6.7 to 75.2 μm. Subjects moved their index fingers with velocity of 20 mm/s on the stimuli. They judged roughness of the stimuli with two-alternative, forced-choice technique. Psychometric functions were calculated from the data of the experiment. Shapes of the psychometric functions were similar to the results predicted by the model. The upper-limit frequency of the low-pass filter was between 400 and 600 Hz.3.In a passive-touch experiment, diffraction gratings, from 33.3 to 150.4 μm in wavelength, were used as stimuli. The stimuli were moved using an experimental instrument with a velocity of 60 mm/s. Subjects touched the moving stimuli and judged the roughness of stimuli. The experimental results coincided with the predictions of the model.The model and the results of the experiments supported the amplitude-information hypothesis.