器物慣量與操作方式引致長度及環境賦使知覺

The inertia of implements and wielding styles induced the perception of lengths and affordances

個體以手揮動器物，藉由肌肉產生力量抵抗器物慣量，可獲得個體－器物間的相對關係，進而覺知器物的特性與其賦予個體達成特定工作的環境賦使，此即動態觸覺（dynamic touch）的概念。目的：本研究旨在探討操作方式與慣量改變，對器物長度與準確性觸擊工作環境賦使知覺的影響。方法：17名無持拍運動訓練經驗之參與者，進行觸擊前、後評估作業（棍棒長度和觸擊工作之適用性評分）、與實際觸擊三階段之評估作業。實驗工作可獲得知覺長度、適用性評分、與實際觸擊之誤差，並以重複量數三因子變異數分析與皮爾森積差相關進行統計分析。結果：當個體操作等長但慣量小之棍棒，會有較短的知覺長度，而評估準確性觸擊的適用分數較高；動態左右之操作方式會引致較長的知覺長度，不影響適用性評分。此外，個體對其棍棒長度覺知較長時，評估之適用分數低，同時以此棍棒執行觸擊動作會有較小的恆常誤差，但有較大的變異誤差。結論：不論操作方式為何，器物慣量改變會影響個體知覺長度與觸擊工作的環境賦使，實際觸擊並不會改變個體動態觸覺以及器物特性與適用性的知覺，且器物慣量引致的知覺長度會影響其適用性與實際觸擊之誤差。People can obtain the individual-implement relationship by using muscular effort to resist inertia of implements, and further to perceive the properties and affordances of objects for individuals to perform specific tasks. This is the concept of dynamic touch. Purpose: This study investigated the influence of wielding styles and the inertia of implements on the perception of lengths and affordances in precise hitting task. Methods: Seventeen participants who were inexperienced in racket or baseball training were recruited. The design of the pre-action ratings - actual hitting - post-action ratings was used as experimental tasks. The perceived length, the suitability rating for the precise hitting, and the errors in actual precise hitting were measured, and these data were analyzed by the 3-way repeated-measures ANOVAs and Pearson correlation coefficient. Results: When participants manipulated a stick with the same length as others but smaller inertia, the perceived length was shorter and the suitability rating was higher. The horizontal wielding induced longer perceived length, but wielding styles couldn't affect the suitability rating. Beside, the longer the perceived length of the stick, the lower the suitability rate and it also induced smaller constant errors but larger variable errors in actual hitting. Conclusion: Whatever wielding styles the participants took, the perceived length and affordances in the hitting task were affected by different inertia of implements. The actual hitting wouldn't change individual's dynamic touch to lead different properties of implement and suitability rating. The perceived length induced by the inertia of implements would affect the suitability and the accuracy of actual hitting.