Wright C E
Dept. of Psychology, Columbia University, New York, NY 10027.
Acta Psychol (Amst). 1993 Mar;82(1-3):5-52. doi: 10.1016/0001-6918(93)90003-a.
Claims that time has a special role in the control of writing and the specific claim that writing time is absolutely invariant across changes in writing size are evaluated in two experiments. The first examined writing time for 24 undergraduate subjects who produced the string eyleyl with the dominant hand or arm in blocked repetitions having different vertical size targets. These variations produced small but systematic changes in writing time. The second experiment explored whether the small range of writing-time variation observed in experiment 1 was due to structural or strategic limitations. This experiment showed, for four undergraduate subjects, that writing time can be varied precisely across a wide range (0.6 to 1.66 of 'normal') while maintaining shape and vertical size constant. Taken together, these experiments suggest that, although relative stroke timing is approximately maintained, absolute timing is not critical to writing. The limited range of writing times typically observed should, rather, be ascribed to a strategic gradient that, along with other influences, broadly defines preferred writing times. This paper also describes a new application of Generalized Procrustes Analysis of shape, and this procedure is applied to the trajectories generated in both experiments. Although several small failures are noted, these analyses generally confirmed previous claims that shape is invariant across changes in writing time, size, and writing with the hand versus the arm. This result is a necessary buttress to the conclusions just described. Shape variability was also assessed in these analyses. This variability soared as writing time was reduced from normal, but showed only a small, insignificant increase as writing time was increased from normal. There were also small, predictable changes in spatial variability across changes in size and effector.
在两项实验中，对时间在书写控制中具有特殊作用这一说法，以及书写时间在书写大小变化时绝对不变这一具体说法进行了评估。第一项实验考察了24名本科受试者用优势手或手臂以不同垂直大小目标进行分组重复书写字符串“eyleyl”时的书写时间。这些变化导致书写时间出现了虽小但系统的改变。第二项实验探究了在实验1中观察到的书写时间变化范围较小是否是由于结构或策略限制所致。对于四名本科受试者，该实验表明，在保持形状和垂直大小不变的情况下，书写时间可以在很宽的范围内（正常时间的0.6至1.66倍）精确变化。综合来看，这些实验表明，尽管相对笔画时间大致保持不变，但绝对时间对书写并不关键。通常观察到的有限书写时间范围，反而应归因于一种策略梯度，该梯度与其他影响因素一起，大致定义了偏好的书写时间。本文还描述了形状广义普罗克汝斯分析的一种新应用，并将此程序应用于两项实验中生成的轨迹。尽管注意到了一些小的失败情况，但这些分析总体上证实了先前的说法，即形状在书写时间、大小以及用手与用手臂书写的变化中是不变的。这一结果是对上述结论的必要支持。在这些分析中还评估了形状变异性。当书写时间从正常时间减少时，这种变异性急剧增加，但当书写时间从正常时间增加时，仅显示出微小且不显著的增加。在大小和效应器变化时，空间变异性也有微小的、可预测的变化。
