Conson Massimiliano, Sacco Simona, Sarà Marco, Pistoia Francesca, Grossi Dario, Trojano Luigi
Neuropsychology Laboratory, Department of Psychology, Second University of Naples, via Vivaldi 43, 81100 Caserta, Italy.
Neuropsychologia. 2008 Sep;46(11):2622-8. doi: 10.1016/j.neuropsychologia.2008.04.015. Epub 2008 Apr 30.
Recent studies indicate that motor imagery is subserved by activation of motor information. However, at present it is not clear whether the sparing of motor efferent pathways is necessary to perform a motor imagery task. To clarify this issue, we required patients with a selective, severe de-efferentation (locked-in syndrome, LIS) to mentally manipulate hands and three-dimensional objects. Compared with normal controls, LIS patients showed a profound impairment on a modified version of the hand-laterality task and a normal performance on mental rotation of abstract items. Moreover, LIS patients did not present visuomotor compatibility effects between anatomical side of hands and spatial location of stimuli on the computer screen. Such findings confirmed that the motor system is involved in mental simulation of action but not in mental manipulation of visual images. To explain LIS patients' inability in manipulating hand representations, we suggested that the pontine lesion, both determined a complete de-efferentation, and affected a component of the motor system, which is crucial for mental representation of body parts, probably the neural connections between parietal lobes and cerebellum.
最近的研究表明，运动想象是由运动信息的激活所支持的。然而，目前尚不清楚运动传出通路的保留对于执行运动想象任务是否必要。为了阐明这个问题，我们要求患有选择性、严重去传入（闭锁综合征，LIS）的患者在脑海中操作手部和三维物体。与正常对照组相比，LIS患者在改良版的手部偏侧性任务上表现出严重受损，而在抽象项目的心理旋转任务上表现正常。此外，LIS患者在手部解剖学侧与计算机屏幕上刺激的空间位置之间未表现出视运动兼容性效应。这些发现证实，运动系统参与动作的心理模拟，但不参与视觉图像的心理操作。为了解释LIS患者无法操作手部表征的原因，我们认为脑桥病变既导致了完全去传入，又影响了运动系统的一个组成部分，该部分对于身体部位的心理表征至关重要，可能是顶叶和小脑之间的神经连接。
