Beyond One Hand: Exploring Underlying Mechanisms of Bimanual Haptic Search

In daily life, we frequently feel for objects without vision using our sense called Haptics. Much of the research that has been done focused on single-handed searches with no agreed-upon conclusion on whether two hands are better than one. Here, we asked if there is a clear advantage, disadvantage, or no difference in simultaneous bimanual compared to sequential unimanual search. Participants felt for a unique target amongst uniformed distractors with their left hand only, right hand only, and with both hands simultaneously. Additionally, we asked how performance might vary when the distinguishing feature of the unique target was the same or different between the hands. Simultaneous bimanual search showed significantly more efficient search than the sequential unimanual search. Surprisingly, there was no appreciable difference between performance when searching for targets with the same and different features. This suggests that the advantage of searching bimanually isn’t due to sensory redundancy or perceptual advantages from shared features. Future research will investigate the role that action coupling might play in the bimanual search advantage. These findings can apply to developments in robotics, prosthetics, and rehabilitation processes. Additionally, they can support our understanding of attentional deployment in understudied modalities like haptics.