Physical Activity, Exercise Physiology, Movement
Adaptive and maladaptive human-robot team dynamics during arm reaching performance
(A. James Clark School of Engineering (UMD) Systems Engineering - Institute for Systems Research Other)
Humans have the capability to learn the biophysical properties of novel environments and/or tools in order to acquire new motor skills. Although many studies have examined motor learning during arm reaching movements, they generally did not consider the following factors: (i) the relationship between motor and cognitive performance (e.g., cognitive workload) and (ii) the dynamics of a context in which two teammates work together to face the challenge. We studied the changes in reaching performance of a virtual robotic arm controlled by user head movements through a human-body machine interface and assessed the corresponding level of cognitive workload. In the first group (safety group), the human user teams-up with an autonomous controller which acts as a safety system by reducing the velocity of the robotic arm within critical regions of the workspace. Outside these regions (i.e., in non-critical regions), the arm moved at a constant velocity. The second group (control group) performed alone, without the autonomous safety system. The participants of both groups performed reaching movements with the robotic arm towards various targets within a two-dimensional workspace. Compared to the control group, the safety group reached the critical regions of the workspace less often; however, they revealed a higher level of cognitive workload. We suspect that the changes in velocity regulated by the autonomous system to help control the robotic arm in the critical regions resulted in a sensorimotor mapping that was different from that used in the non-critical regions. Thus, the safety group had to learn to control the robotic arm through a piecewise mapping, which may have increased the cognitive workload. This work increases our understanding of the underlying cognitive-motor processes of arm reaching movements in the context of human-robot team dynamics and can inform the design of novel generations of assistive technology.
Importance to public health: