ABSTRACT
Encoding the location of tactile features during active exploration poses at least two problems for a perceptual system. First, as the hand is moved through space, processing delays may displace the perceived locations of features. Second, due to the sequential nature of the process, some form of memory, which itself may be subject to spatial distortions, is required for integration of spatial samples. This chapter investigates these issues using a task involving active haptic exploration with a stylus swept back and forth in the horizontal plane by flexing and extending the wrist. For a given sector, results for various offsets between the first and second force pulse were used to derive a psychometric function, and probit analysis was used to determine the point of subjective equality, that is, the amount by which the second pulse had to be offset with respect to the first to appear coincident with it.
