Department of Physiology, Anatomy and Genetics, Oxford University, South Parks Road, Oxford, OX1 3QX England, United Kingdom; Social, Cognitive and Affective Neuroscience Unit, Faculty of Psychology, University of Vienna, Liebiggasse 5, 1010 Vienna, Austria(1).
Neurosci Res. 2013 Sep-Oct;77(1-2):50-7. doi: 10.1016/j.neures.2013.08.002. Epub 2013 Aug 19.
Concurrent eye and hand movements toward a common visual target require different motor programs based on identical visual input. We used event-related brain potentials (ERP) to determine if and when the processing of the visual target differs for the two motor systems. The N2, an index for target evaluation, was more negative for the target of a hand than of an eye movement in two experiments. A possible interpretation for this finding is different visual target processing. Targets for hand movements require a different weighting of visual information, for example concerning features such as surface structure which are important for hand but not for eye movements. In experiment 2, the early C1-component, which had an average maximum at 67 ms following target onset, was significantly more negative when subjects pointed at the stimuli. Traditionally, the C1 has been regarded as a sensory component, but recent studies have linked it to higher order processing, such as attention and expectations. Thus, the present data indicate that target processing for eye or hand movements is already context-specific during early visual information processing. We suggest that differences in a target's relevance for upcoming movements modify target processing as well as sensory expectations.
同时朝向共同视觉目标的眼睛和手部运动需要基于相同视觉输入的不同运动程序。我们使用事件相关脑电位 (ERP) 来确定这两个运动系统对视觉目标的处理是否以及何时存在差异。在两项实验中，手部运动目标的 N2（用于目标评估的指标）比眼部运动目标更负。这一发现的一种可能解释是视觉目标的处理不同。手部运动的目标需要对视觉信息进行不同的加权，例如，对手部运动很重要但对眼部运动不重要的表面结构等特征。在实验 2 中，当受试者指向刺激物时，起始后平均最大潜伏期为 67 毫秒的早期 C1 成分明显更负。传统上，C1 被认为是一个感觉成分，但最近的研究将其与更高阶的处理，如注意力和期望联系起来。因此，目前的数据表明，眼睛或手部运动的目标处理在早期视觉信息处理过程中已经具有上下文特异性。我们认为，即将到来的运动对目标的重要性差异会改变目标处理以及感觉预期。
