Department of Psychology, Grinnell College, Grinnell, IA 50112, USA.
Department of Physical Therapy, Movement and Rehabilitation Sciences, Northeastern University, Boston, MA 02115, USA.
Hum Mov Sci. 2021 Apr;76:102752. doi: 10.1016/j.humov.2020.102752. Epub 2021 Jan 16.
The 'quiet eye' (QE) approach to visually-guided aiming behavior invests fully in perceptual information's potential to organize coordinated action. Sports psychologists refer to QE as the stillness of the eyes during aiming tasks and increasingly into self- and externally-paced tasks. Amidst the 'noisy' fluctuations of the athlete's body, quiet eyes might leave fewer saccadic interruptions to the coupling between postural sway and optic flow. Postural sway exhibits fluctuations whose multifractal structure serves as a robust predictor of visual and haptic perceptual responses. Postural sway generates optic flow centered on an individual's eye height. We predicted that perturbing the eye height by attaching wooden blocks below the feet would perturb the putting more so in QE-trained participants than participants trained technically. We also predicted that QE's efficacy and responses to perturbation would depend on multifractality in postural sway. Specifically, we predicted that less multifractality would predict more adaptive responses to the perturbation and higher putting accuracy. Results showed that lower multifractality led to more accurate putts, and the perturbation of eye height led to less accurate putts, particularly for QE-trained participants. Models of radial error (i.e., the distance between the ball's final position and the hole) indicated that lower estimates of multifractality due to nonlinearity coincided with a more adaptive response to the perturbation. These results suggest that reduced multifractality may act in a context-sensitive manner to restrain motoric degrees of freedom to achieve the task goal.
“静眼”（QE）方法用于视觉引导的瞄准行为，充分利用了知觉信息组织协调动作的潜力。体育心理学家将 QE 称为瞄准任务中的眼睛静止状态，并越来越多地用于自我和外部计时任务。在运动员身体的“嘈杂”波动中，静眼可能会减少姿势摆动和光流之间耦合的眼球跳动中断。姿势摆动表现出波动，其多重分形结构是视觉和触觉感知反应的有力预测指标。姿势摆动产生以个体眼睛高度为中心的光流。我们预测，通过在脚下附加木块来扰乱眼睛高度会使推杆更不稳定，尤其是在接受 QE 训练的参与者中比接受技术训练的参与者中更不稳定。我们还预测，QE 的功效和对扰动的反应将取决于姿势摆动的多重分形性。具体来说，我们预测较小的多重分形性将预测对扰动的更自适应反应和更高的推杆准确性。结果表明，较低的多重分形性导致更准确的推杆，而眼睛高度的扰动导致更不准确的推杆，尤其是对于接受 QE 训练的参与者。径向误差（即球的最终位置和孔之间的距离）的模型表明，由于非线性导致的多重分形性的较低估计与对扰动的更自适应反应一致。这些结果表明，减少多重分形性可能以上下文敏感的方式作用于约束运动自由度以实现任务目标。
