Publication:

單維直線運動是否符合Fitts定律的預測

在Fitts的典範工作中，動作難度通常被拿來當作測量人類動作行為的訊息處理能力指標。本研究的主要目的係透過單維直線拖曳運動檢測動作難度與動作時間是否能符合Fitts定律的預測，並分析比較其動作過程中所產生的最大速度、最大速度標準差、最大速度位置點以及最大速度位置百分比等運動學參數。實驗參加者為15名健康成年人（20.8 ± 2.3歲），實驗要求參加者在線性移動儀（Gefran Model PK-M-0600-L）上反覆快速來回拖曳感應器到達所設置目標區，實驗共分成7組工作，分別由2公分和4公分的目標寬度與4公分、8公分、16公分、32公分之動作距離組合而成（共4種難度）。實驗的數據由Biopac MP-150 system （1000Hz）收集，並由AcqKnowledge 3.9.1版本軟體進行分析。實驗透過簡單線性迴歸分析三種計算方式檢測動作難度是否能預測動作時間，運動學參數以重複量數單因子變異數分析，並以HSD法進行事後比較，統計水準定為α = .05。研究結果顯示，本研究所採用的單維反覆拖曳工作可以符合Fitts定律的預測，且本研究發展之中心位置法能更合理的解釋實際動作之位置。單維反覆拖曳工作的運動學特徵，顯示參加者的最大動作速度隨著不同動作距離的增加而增加（p < .05），卻不受目標區大小所影響（p > .05）。此外，無論動作距離與目標區寬度為何，其加速距離皆佔全程工作距離的65%左右，所以單維反覆拖曳工作的加速距離相對於全程工作距離的百分比，不會受到工作距離與目標區寬度的不同而有所差異。

In the paradigm of Fitts’ law (1954), the task difficulty is always measured in bits to assess the cognitive information processing capacity of the behavior of the human motor system. The aim of this study was to examine the logarithmic relationship between the movement time and the index of difficulty (ID) that is determined in requirement of task or actual performance for one dimension dragging tasks, and also compared the kinematical characteristics among the different target widths or amplitudes. Fifteen adults (20.8 ± 2.3 years old) were recruited as the participants for this study. Participants were required to perform reciprocal dragging tasks on a linear displacement meter (Gefran Model PK-M-0600-L) under the conditions of two target widths and four movement amplitudes (four IDs in total). The Biopac MP-150 system (1000Hz) with AcqKnowledge ver. 3.9.1 was used to record and analyse the position change of reciprocal linear motion. In the approach of simple regression analysis, the ID was used to predict the movement time (MT). Repeated measures one-way ANVOA and HSD post hoc tests were used to test the statistical differences for kinematical parameters with the alpha level .05. The results of regression analysis showed the relationship between movement time and ID were coincide with the predicted by Fitts’ law for one dimension dragging tasks. The method of the center of position explained the real movement position reasonable and logical. The kinematical characteristics of one dimension dragging tasks showed the peak velocity was increased following the extended of movement amplitude (p < .05), but not in the target width (p > .05). Moreover, the acceleration distance was around 65% of movement amplitude regardless of the movement amplitude and target width. It indicated that the relative distance of acceleration was not the function of movement amplitude for one dimension dragging tasks, either target width.