An exploration on the integration of vibrotactile and force cues for 3D interactive tasks

Abstract

Vibrotactile and force cues of the haptic modality is increasing used to facilitate interactive tasks in three-dimensional (3D) virtual environments (VE). While maximum likelihood estimation (MLE) explains the integration of multi-sensory cues in many studies, an existing work yielded mean and amplitude mismatches when using MLE to interpret the integration of vibrotactile and force cues. To investigate these mismatches, we proposed mean-shifted MLE and conducted a study of comparing MLE and mean-shift MLE. Meanshifted MLE shared the same additive assumption of the cues as MLE, but took account mean differences of both cues. In a VE, the study replicated the visual scene, the 3D interactive task, and the cues from the existing work. All human participants in the study were biased to rely on the vibrotactile cue for their task, departing from unbiased reliance towards both cues in the existing work. After validating the replications, we applied MLE and mean-shifted MLE to interpret the integration of the vibrotactile and force cues. Similar to the existing work, MLE failed to explain the mean mismatch. Mean-shifted MLE remedied this mismatch, but maintained the amplitude mismatch. Further examinations revealed that the integration of the vibrotactile and force cues might violate the additive assumption of MLE and mean-shifted MLE. This sheds a light for modeling the integration of vibrotactile and force cues to aid 3D interactive tasks within VEs.