Application of psychophysical techniques to haptic research.

Various psychophysical methods have been used to study human haptic perception, although the selection of a particular method is often based on convention, rather than an analysis of which technique is optimal for the question being addressed. In this review, classical psychophysical techniques used to measure sensory thresholds are described as well as more modern methods such as adaptive procedures and those associated with signal detection theory. Details are provided as to how these techniques should be implemented to measure absolute and difference thresholds and factors that influence subjects' responses are noted. In addition to the methods used to measure sensory thresholds, the techniques available for measuring the perception of suprathreshold stimuli are presented. These scaling methods are reviewed in the context of the various stimulus and response biases that influence how subjects respond to stimuli. The importance of understanding the factors that influence perceptual processing is highlighted throughout the review with reference to experimental studies of haptic perception.