Prospective motor control on tabletops

Abstract

Substantial amount of research in Psychology has studied how people manipulate objects in the physical world. This work has unveiled that people show strong signs of prospec tive motor planning, i.e., they choose initial grasps that avoid uncomfortable end postures and facilitate object manipula tion. Interactive tabletops allow their users great flexibility in the manipulation of virtual objects but to our knowledge pre vious work has never examined whether prospective motor control takes place in this context. To test this, we ran three experiments. We systematically studied how users adapt their grasp when asked to translate and rotate virtual objects on a multitouch tabletop. Our results demonstrate that target posi tion and orientation significantly affect the orientation of fin ger placement on the object. We analyze our results in the light of the most recent model of planning for manipulating physical objects and identify their implications for the design of tabletop interfaces.

WallTokens: Surface Tangibles for Vertical Displays

“…This is consistent with previous experiments (experiment 2 in [52], and lateral condition in [17]) where participants were faster for clockwise rotations (−90°) than for counterclockwise rotations (90°) with touch gestures. This might be because of a lower cost of movement planning [37] for right-handed users for clockwise rotations than for counterclockwise rotations. In comparison, Wall-Tokens are less sensitive to differences in orientations.…”

Manipulation, Learning, and Recall with Tangible Pen-Like Input

“…Many factors influence how a device is gripped and manipulated. For instance, Olafsdottir et al found grip is influenced by hand position, target position, and anticipated rotation when manipulating graphical objects on a tabletop [14]. However these are not tangible objects, and they do not control for object size.…”

TouchTokens

“…The cross can be in five different LOCATION. These locations are chosen on a semi-circle roughly centered on the participant as in [38] (see Figure 6), as the token's location on the surface (relative to the participant) may influence the neutral hand posture and thus how the token is grasped. The distance between the touch pattern's centroid and the center of the cross must be at most 50px.…”

“…Participants then have to slide the token along the path indicated by purple arrows. In this condition, participants can plan a manipulation with the token, which may influence their initial grasp [38]. When sliding the token, they can lift some fingers but must keep at least one finger in contact with the surface.…”