Characterization of 2D Precision and Accuracy for Combined Visual-Haptic Localization

Madeline Fischer ¹ Umberto Saetti ^2* Martine Godfroy-Cooper ³ Douglas Scott Fischer ⁴

• ¹ University of Maryland, College Park, College Park, Maryland, United States
• ² Center for Environmental Science, University of Maryland, College Park, Cambridge, United States
• ³ Airbus (France), Toulouse, Occitanie, France
• ⁴ Boeing (United States), Chicago, Illinois, United States

This article describes a combined visual and haptic localization experiment focused on multimodal cueing. The investigation aimed to characterize the two-dimensional (2D) localization precision and accuracy of visual, haptic, and combined visual-haptic targets within peri-personal space—the area around the body where sensory information is perceived as ecologically relevant. Participants were presented with visual, haptic, or bimodal cues using a body-centered reference frame and instructed to indicate the perceived target location using a mouse pointer under open-loop feedback conditions.The study analyzed unimodal (visual and haptic) and bimodal (combined visual-haptic) localization performance using a Bayesian integration model to understand the nature of multisensory combination. The results revealed distinct characteristics of visual and haptic perceptive fields in terms of localization performance. Visual localization demonstrated well-known radial characteristics, while haptic localization showed a nonlinear pattern influenced by the midline of the torso and cutaneous regions on either side.Interestingly, bimodal cueing did not improve precision compared to the best unimodal condition, vision, suggesting sensory combination rather than optimal integration as predicted by the Maximum Likelihood Estimation (MLE) model. The hypothesis that bimodal accuracy would compromise between visual and haptic performance in favor of the more precise modality was also rejected. Instead, bimodal accuracy was equivalent to or exceeded that of vision alone, indicating a unique interaction between the two modalities.These findings provide insights into the sensorimotor processes employed by the brain and highlight the value of leveraging natural differences between vision and haptic perception to understand their interaction. The results have implications for designing human-machine interfaces with haptic feedback mechanisms, particularly in aviation contexts. Haptic localization can enhance situational awareness, improve spatial orientation, reduce workload, and ultimately contribute to safer operations. For future aircraft systems, haptic feedback could help pilots overcome visual illusions and reconcile discrepancies between visual and vestibular inputs, especially in degraded visual environments. These findings underscore the potential benefits of multimodal perception in enhancing pilot performance and operational safety.