Perception of Force with Haptic Interface

The present study is one of multidisciplinary works aimed to understand the processes characterizing the human haptic system. Such set of biomechanical, psychophysical and neurophysiological studies are also aimed to derive a solid scientific basis for haptic device design. A fundamental problem of Psychophysics is the stochastic nature of sensory thresholds due to the presence of an infinite number of imponderables in the perceptual system. How to measure differential limens, i.e. the minimum difference between two stimuli that can be perceived, is a very old problem for which many techniques have been developed since the pioneering works. A recent progress, linked to the advent of computers, is the development of adaptative methods, which can compute limens efficiently by selecting the stimuli in an optimal way. Our first objective is to verify whether haptic interfaces could be used to study human sensory thresholds for force perception. The second objective of this study is to collect data to validate a psychophysical method to compute differential limens that is based on the QUEST. To address this issue, we used two QUESTs and measured sensory thresholds in distinct conditions