  Teleoperation is increasingly recognized as a viable solution for deploying
robots in hazardous environments. Controlling a robot to perform a complex or
demanding task may overload operators resulting in poor performance. To design
a robot controller to assist the human in executing such challenging tasks, a
comprehensive understanding of the interplay between the robot's autonomous
behavior and the operator's internal state is essential. In this paper, we
investigate the relationships between robot autonomy and both the human user's
cognitive load and trust levels, and the potential existence of three-way
interactions in the robot-assisted execution of the task. Our user study (N=24)
results indicate that while autonomy level influences the teleoperator's
perceived cognitive load and trust, there is no clear interaction between these
factors. Instead, these elements appear to operate independently, thus
highlighting the need to consider both cognitive load and trust as distinct but
interrelated factors in varying the robot autonomy level in shared-control
settings. This insight is crucial for the development of more effective and
adaptable assistive robotic systems.
