Haptic perception is an active process in which people take in information in a targeted manner. For example, if we want to feel how soft an object is, we must first explore it appropriately so that the sensors pick up relevant information. We investigate the mechanisms controlling the motion-perception feedback loop in human sensing. In doing so, we hypothesize that humans perform their sensing movements "optimally". Further research focuses on the perception of softness, emotional-motivational aspects of haptic perception, time perception, and the interplay of sensing and seeing, e.g., by means of the "size-weight illusion".