Ley Pia, Röder Brigitte
Multisens Res. 2014;27(2):139-60. doi: 10.1163/22134808-00002445.
The present study investigated whether effects of movement preparation and visual spatial attention on visual processing can be dissociated. Movement preparation and visual spatial attention were manipulated orthogonally in a dual-task design. Ten participants covertly prepared unimanual lateral arm movements to one hemifield, while attending to visual stimuli presented either in the same or in the hemifield opposite to the movement goal. Event-related potentials to task-irrelevant visual stimuli were analysed. Both joint and distinct modulations of visual ERPs by visual spatial attention and movement preparation were observed: The latencies of all analysed peaks (P1, N1, P2) were shorter for matching (in terms of direction of attention and movement) versus non-matching sensory-motor conditions. The P1 amplitude, as well, depended on the sensory-motor matching: The P1 was larger for non-matching compared to matching conditions. By contrast, the N1 amplitude showed additive effects of sensory attention and movement preparation: with attention and movement preparation directed towards the visual stimulus the N1 was largest, with both directed opposite to the stimulus the N1 was smallest. P2 amplitudes, instead, were only modulated by sensory attention. The present data show that movement preparation and sensory spatial attention are tightly linked and interrelated, showing joint modulations throughout stimulus processing. At the same time, however, our data argue against the idea of identity of the two systems. Instead, sensory spatial attention and movement preparation seem to be processed at least partially independently, though still exerting a combined influence on visual stimulus processing.
本研究调查了运动准备和视觉空间注意对视觉加工的影响是否可以分离。在一项双任务设计中，对运动准备和视觉空间注意进行了正交操纵。十名参与者在暗中准备向一个半视野进行单侧手臂运动的同时，关注与运动目标同侧或对侧半视野中呈现的视觉刺激。分析了对任务无关视觉刺激的事件相关电位。观察到视觉空间注意和运动准备对视觉ERP的联合调制和独特调制：在匹配（就注意和运动方向而言）与不匹配的感觉运动条件下，所有分析峰值（P1、N1、P2）的潜伏期都更短。P1波幅也取决于感觉运动匹配：与匹配条件相比，不匹配时P1波幅更大。相比之下，N1波幅显示出感觉注意和运动准备的相加效应：当注意和运动准备都指向视觉刺激时，N1波幅最大，当两者都与刺激方向相反时，N1波幅最小。相反，P2波幅仅受感觉注意的调制。目前的数据表明，运动准备和感觉空间注意紧密相连且相互关联，在整个刺激加工过程中表现出联合调制。然而，与此同时，我们的数据反对这两个系统完全相同的观点。相反，感觉空间注意和运动准备似乎至少部分是独立加工的，尽管仍然对视觉刺激加工产生综合影响。
