Smyth M M
Acta Psychol (Amst). 1989 May;70(3):253-65. doi: 10.1016/0001-6918(89)90025-5.
In this experiment adult subjects copied three types of material (letters, reversed letters and geometric shapes) with and without sight of the hand and the writing trace. Without vision the number of movement segments decreased and the sequence and direction of movements were altered. This means that subjects did not use a fixed stored representation to produce items nor did they obey the rules of Goodnow and Levine's (1973) grammar of action. When spatial location is made more difficult by the removal of vision, movement production is simplified to reduce the number of relocations required. The use of consistent directions of movement depends on the ability to use visual control of spatial location.
在本实验中，成年受试者在可见和不可见手部及书写轨迹的情况下抄写三种类型的材料（字母、反转字母和几何形状）。在没有视觉的情况下，动作片段的数量减少，动作的顺序和方向发生改变。这意味着受试者既没有使用固定的存储表征来生成项目，也没有遵循古德诺和莱文（1973年）动作语法的规则。当通过去除视觉使空间定位变得更加困难时，动作产生会被简化以减少所需的重新定位次数。动作方向一致性的使用取决于利用视觉控制空间定位的能力。
