Preserved adjustment but impaired awareness in a sensory-motor conflict following prefrontal lesions
Preserved adjustment but impaired awareness in a sensory-motor conflict following prefrontal lesions
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DOI：
10.1162/08989290151137386
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发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Dubois, B
中科院分区：
文献类型：
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作者：
Slachevsky, A;Pillon, B;Dubois, B
对行动的控制发生在执行过程的不同阶段，特别是在感觉-运动整合和意识监控的阶段。这项研究的目的是确定前额叶皮质在行为控制中的意义。为此，我们比较了15名额叶病变患者和15名匹配对照在产生行动计划和感觉-运动反馈之间冲突的实验范式上的表现。受试者必须用触控笔在图形平板电脑上画出一条矢状线。这只手被一面镜子遮住了，被计算机处理的轨迹线被投射到镜子上。在没有通知受试者的情况下，追踪的线条被修改，引入了向右的偏向，从2逐渐增加到42。为了完成这项任务，受试者必须修改他们的运动程序，并将他们的手偏离相反的方向。通过被跟踪的线与理想线之间的表面积来评估感觉-运动对偏差的调节，以补偿偏差。对冲突的认识是通过被试表达他们所追踪的线与他们所看到的线不同的感觉的偏见的角度来衡量的。患者和对照组的偏差也同样得到了补偿，直到24度。然后是14名对照组，但只有3名患者意识到了冲突。在此之后，对于不知情的患者，表现的变异性显著增加。这些结果表明，前额叶皮质在有意识的行为监测水平上是必需的，但在感觉-运动整合水平上也不是。
Control of action occurs at different stages of the executive process, in particular at those of sensory-motor integration and conscious monitoring. The aim of this study was to determine the implication of the prefrontal cortex in the control of action. For that purpose, we compared the performance of 15 patients with frontal lobe lesions and 15 matched controls on an experimental paradigm generating a conflict between the action planned and the sensory-motor feedback. Subjects had to trace a sagittal line with a stylus on a graphic tablet. The hand was hidden by a mirror on which the traced line, processed by a computer, was projected. Without informing the subjects, the line traced was modified by introducing a bias to the right, which increased progressively from 2 to 42. To succeed the task, subjects had to modify their motor program and deviate their hand in the opposite direction. The sensory-motor adjustment to the bias was evaluated by the surface between the line traced and the ideal line to compensate for the deviation. The awareness of the conflict was measured by the angle of the bias at which subjects expressed the feeling that the line they traced was not the same as the line they saw. The deviation was similarly compensated for by patients and controls until 24 degrees. Then 14 controls but only 3 patients were aware of a conflict. After that, the variability of performance increased significantly for the unaware patients. These results suggest that the prefrontal cortex is required at the level of conscious monitoring of actions, but nor at the level of sensory-motor integration.