Evaluation of Point of Subject Equality Using Constant Method in Pseudo Force Sensation by Pressure Stimulation to the Palm*

Abstract

A psycho-physical experiment using constant method was conducted to investigate the characteristics of pseudo force sensation caused by pressurization to a palm. Kinesthetic force stimulus and tactile pressure stimulus were given to a subject at the same time, and their effect on force perception was investigated. Previous studies have reported two contradicting results regarding whether the strength of pseudo force sensation depends on the pressure or on the total amount of force. This paper further investigated this aspect using three types of indenters which differ in shape and width. The results suggested that the pseudo force sensation does not depend on total force. This, however, does not simply mean that the sensation depends on the pressure and the need for further investigations remains. The results found significant differences among subjects but also suggested that the narrower indenter with an integrated body is less susceptible to individual differences among subjects.