Relationship between Perceived Maneuverability and Involuntary Eye Movements under Systematically Varied Time Constants of Ride-on Machinery

Studies suggest that involuntary eye movements exhibit greater stability during active motion compared to passive motion, and this effect may also apply to the operation of ride-on machinery. Moreover, a study suggested that experimentally manipulating the sense of agency (SoA) by introducing delays may influence the stability of involuntary eye movements. Although a preliminary investigation examined involuntary eye movements and perceived maneuverability under two distinct machine dynamics with preserved SoA, it remains unclear how systematic variations in motion dynamics influence these factors. Therefore, the purpose of the present research was to investigate whether systematic variations in the dynamic properties of a ride-on machine, where the perceived maneuverability is modulated, influence the accuracy of involuntary eye movements in human operators. Participants rode a yaw-rotational platform whose time constant from joystick input to motor torque of a rotational machine was systematically manipulated. During the operation, eye movements were recorded while participants fixated on a visual target. After each condition, participants provided subjective ratings of maneuverability and cognitive load. As the platform's time constant increased, the perceived maneuverability scores decreased while the cognitive loads increased. Concurrently, involuntary eye movement accuracy decreased. Moderate to weak positive correlations emerged between the perceived maneuverability scores and the eye movement gain and accuracy, while a weak negative correlation was found with cognitive load.