Submission 284
Visual and Tactile Contributions to Coordination During Object Handovers
MixedTopicTalk-02
Presented by: Knut Drewing
Handing an object from one person to another is a common yet surprisingly complex everyday action. Successful give-and-take requires precise coordination: the giver must retain their hold until the taker establishes a secure grip, while the taker must delay moving the object until the giver releases it. Both visual cues and tactile feedback likely contribute to this coordination. Here, we examined handover as a function of object weight (200–1000 g), object height (4–20 cm), and the availability of visual information (vision of hand versus blindfolded). Pairs of participants sat opposite each other at a table. In each trial, a designated giver lifted a cylindrical object (6 cm diameter) and transported it to the table’s center, where the taker received it midair and placed it back on the surface. Then the taker assumed the role of giver to hand the object back. There were four trials per object and visual condition. Using video recordings, we measured handover duration, the interval during which both partners simultaneously contacted the object. Handover durations were longer when participants were blindfolded compared to when vision was available. Duration also increased with object weight, with weight effects being substantially larger without vision. In contrast, object height had no measurable impact. These findings indicate that tactile information alone is sufficient to support give-and-take coordination, but vision markedly enhances efficiency. Notably, the visual benefit interacted with the invisible object weight, suggesting that vision facilitates both the initial planning and the real-time fine-tuning required for seamless human handovers.