McIntosh Robert D, Ambron Elisabetta, Della Sala Sergio
Human Cognitive Neuroscience, University of Edinburgh, Edinburgh, UK.
Cogn Neuropsychol. 2008 May;25(3):376-94. doi: 10.1080/02643290802028981.
"Closing-in behaviour" (CIB) is a phenomenon observed on copying and imitation tasks, in which the copy is made inappropriately close to or on top of the model. CIB is classified clinically as a manifestation of constructional apraxia (CA), but its underlying causes are not understood. Compensation hypotheses propose that CIB is a strategic adaptation to underlying deficits in visuospatial and/or memory functions. The attraction hypothesis suggests that CIB reflects a primitive default behaviour in which the acting hand is drawn towards the focus of visual attention. We tested between these hypotheses in a 62-year-old woman with moderate Alzheimer's disease precipitating CA and apraxia, who showed marked CIB in graphic copying and gesture imitation. We presented two dual tasks: In the first, a straight-line drawing task was combined with a letter-reading task; in the second, simple gesture production was combined with a letter-reading task. In each case, the patient's productions deviated markedly towards the location of the reading task. These data provide strong support for the attraction hypothesis and show that CIB is not specific to copying.
“靠近行为”（CIB）是在复制和模仿任务中观察到的一种现象，即在复制时不恰当地靠近模型或置于模型之上。CIB在临床上被归类为结构性失用症（CA）的一种表现，但其根本原因尚不清楚。补偿假说提出，CIB是对视觉空间和/或记忆功能潜在缺陷的一种策略性适应。吸引假说表明，CIB反映了一种原始的默认行为，即执行动作的手被吸引到视觉注意的焦点。我们在一名62岁患有中度阿尔茨海默病并引发CA和失用症的女性患者身上对这些假说进行了测试，该患者在图形复制和手势模仿中表现出明显的CIB。我们呈现了两项双重任务：第一项任务中，直线绘制任务与字母阅读任务相结合；第二项任务中，简单手势制作与字母阅读任务相结合。在每种情况下，患者的表现都明显朝着阅读任务的位置偏移。这些数据为吸引假说提供了有力支持，并表明CIB并非复制所特有。
