Mid-air haptic congruence with virtual objects modulates the implicit sense of agency

Hand-tracking technologies allow interactions with virtual environments unmediated by any physical tool. Mid-air haptic technologies further this interaction paradigm by providing the user with tactile feedback. As an additive sensation not strictly bound to physical-based laws of objects, there is much room for exploration of various integration methods. Here, we investigate whether the psychological variable known as the sense of agency (SoA) is sensitive to variations of a mid-air haptic stimulus, where SoA captures the user’s feeling of control and causal influence in the virtual environment. To that end, we use a virtual button press-tone (action-effect paradigm) to measure SoA at the behavioural level as well as through self-report. Mid-air haptics accompanying the visual element of the virtual button press were varied at 4 levels: dynamic, fixed, on completion and no feedback. Results show a significant influence at the behavioural level but were not self-reported. Additive mid-air haptics that was not congruent with the visual elements negatively impacted the implicit feeling of SoA.