Helmich I, Lausberg H
Department of Neurology, Psychosomatic Medicine and Psychiatry, Institute of Health Promotion and Clinical Movement Science, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany,
Exp Brain Res. 2014 Oct;232(10):3159-73. doi: 10.1007/s00221-014-4006-x. Epub 2014 Jun 11.
The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that represent action stem from a left hemispheric system of conceptualization.
本研究探讨了先前讨论过的关于左右脑半球对自发手部运动和手势的产生及概念化所做贡献的争议。尽管已经表明每个半球都具备产生手部运动的能力，但左半球侧化运动功能的结果对侧手运动产生系统的观点提出了挑战。为了研究半球在手部运动和手势产生方面的特化，对10名右利手参与者进行了速示呈现日常生活动作图片的实验。要求参与者用手演示但不说话，展示他们在图片上看到的内容。两名独立的盲评者使用神经心理学手势编码系统对录像中的手部运动和手势进行评估。结果显示，无论刺激的侧化情况如何，右手和左手运动的总体频率是相等的。当从结构角度分析手部运动时，向左半球呈现动作刺激会导致比向右半球呈现时更多具有相位结构的手部运动。此外，向左半球呈现刺激会导致更多具有相位结构的右手和左手运动，而向右半球呈现刺激时，与无相位结构的手部运动相比，仅增加了具有相位结构的对侧左手运动。描绘动作的手势主要是对右侧视野呈现的刺激做出反应，而非左侧视野。本研究表明，两个半球都具备对动作刺激做出反应而产生手部运动的能力。然而，左半球在具有相位结构的手部运动和描绘动作的手势产生方面占主导地位。因此，我们得出结论，具有相位结构的手部运动和代表动作的手势源于左半球的概念化系统。
