Grasping motions led by visuo-haptic signals are most effective

NYU Abu Dhabi Assistant Professor of Psychology Robert Volcic and Postdoctoral Associate Ivan Camponogara compared participants' grasping movements towards an object sensed through visual, haptic, or visuo-haptic signals using special sensors capable of measuring hand and fingers movement in real-time.

When movements were based on haptic information only, hand pre-shaping was initiated earlier, fingers closed on the object more slowly, and the final phase was more cautious compared to movements based on only visual information. Instead, the simultaneous availability of vision and haptics led to faster movements and to an overall decrease of the grip aperture.

"Our findings also show that each modality contributes to a different extent in different phases of the movement, with haptics being more crucial in the initial phases and vision being more important for the final on-line control," said Volcic. "We confirmed that vision and haptics can be flexibly combined to optimize the execution of grasping movement."