Forde E M, Humphreys G W
Neurosciences Research Institute, Aston University, Birmingham, United Kingdom.
Brain Cogn. 2000 Nov;44(2):214-52. doi: 10.1006/brcg.2000.1229.
We present a single case study of a patient, HG, who was severely impaired on routine everyday tasks, such as cleaning his teeth and preparing a cup of tea. We used the Action Coding System developed by Schwartz et al. (1991) to provide quantitative and qualitative measures of his performance in a number of experimental manipulations: (a) with task-congruent objects only, (b) with task-congruent objects and semantic distractors, (c) with a set of written commands to follow, (d) when he was given one command at a time, (e) when he was shown how the task should be performed before starting himself, and (f) when the task was divided into smaller subgoals. In general, the majority of HG's errors were step omissions, perseverations, sequence errors, and semantic errors. These semantic errors are particularly interesting since HG was able to name, gesture to, and define all the objects when they were presented in isolation or in task-congruent arrays. We suggest that semantic errors may arise for a number of reasons: (1) impaired access from semantic memory to a network representing action schema, (2) degradation of stored schema, and (3) behavior that is abnormally driven by the goal, by preceding actions, or by salient objects rather than by an appropriate association between these elements in working memory.
我们呈现了一个关于患者HG的单病例研究，他在日常常规任务中存在严重障碍，比如刷牙和泡茶。我们使用了施瓦茨等人（1991年）开发的动作编码系统，对他在一系列实验操作中的表现提供定量和定性的测量：（a）仅使用与任务相符的物体，（b）使用与任务相符的物体和语义干扰物，（c）遵循一组书面指令，（d）每次给他一个指令时，（e）在他自己开始之前向他展示任务应如何执行时，以及（f）当任务被分解为更小的子目标时。总体而言，HG的大多数错误是步骤遗漏、持续动作、顺序错误和语义错误。这些语义错误尤其有趣，因为当物体单独呈现或呈现在与任务相符的阵列中时，HG能够说出其名称、做出手势并进行定义。我们认为语义错误可能由于多种原因产生：（1）从语义记忆到表示动作图式的网络的访问受损，（2）存储图式的退化，以及（3）行为受到目标、先前动作或显著物体的异常驱动，而非由工作记忆中这些元素之间的适当关联驱动。
