Analysis of Control Characteristics for Circular Tracking Movements with Rapidly Changing Target Speeds in 3D VR Environment

Visual information-based movements are crucial in everyday life, and movements involving rapid speed changes (e.g., acceleration and deceleration) are essential for analyzing actual human motor control characteristics. This study is relevant because it was conducted in 3D VR, which reflects similar movements as real movements, unlike motor control research conducted in 2D. In addition, the human motor control characteristics were quantitatively analyzed by extracting accurate positional data. This study selected three parameters (ΔD, Δθ, and Δω) to analyze the motor control characteristics resulting from rapid speed changes. We performed circular tracking movements with a target exhibiting speed changes in the frontal and sagittal planes. Unlike for uniform and decelerated motion, the largest errors in all the parameters for accelerated motion were observed owing to the influence of feedforward control, with the most impact occurring when the speed increased between 0.375 Hz and 0.438 Hz. During decelerated motion, two parameters (ΔD, Δθ) were used to observe the effects of brain time delay (sensorimotor delay, somatosensory delay) and trajectory learning models, with the most significant influence occurring as the speed decreased between 0.188 Hz and 0.156 Hz. By comparing the frontal and sagittal planes for each speed change, we confirmed that the accuracy of the visual information in the planes significantly influenced motor control more than the speed changes. Furthermore, by analyzing the quadrants in the sagittal plane, we found that the control strategies for adapting to speed changes were more impactful than the accuracy of the visual information based on the target position.