Staines W Richard, Padilla Mayra, Knight Robert T
Department of Psychology and the Helen Willis Neuroscience Institute, University of California at Berkeley, Berkeley, CA, USA.
Brain Res Cogn Brain Res. 2002 Apr;13(2):195-202. doi: 10.1016/s0926-6410(01)00113-6.
Learning novel visuomotor tasks requires precise processing and transformation of incoming sensory information to produce accurate motor responses. The present study characterized neural activity associated with sensorimotor processes during novel visuomotor learning. We hypothesized that the acquisition of a visuomotor skill would be accompanied by experience-dependent modulation of sensorimotor cortical activity. Subjects controlled a cursor on a computer screen with a joystick. With the goal to move the cursor to a cued target after a brief delay, the relationship between joystick and cursor movement was manipulated such that joystick movement controlled cursor velocity, not displacement (rate task). Individual trials in this task were further divided into early (rate1) and late (rate2) blocks. Event-related potentials (ERPs) were averaged to target presentation, the cue for movement, and movement onset. Subjects were more accurate after practice in late rate2 compared to early rate1 blocks. ERPs associated with movement onset were larger in amplitude and occurred earlier over centroparietal sites following practice. In contrast, ERPs to the cue to move were enhanced frontocentrally initially and diminished with practice. The results suggest that practice on a novel visuomotor task is associated with changes in frontoparietal networks involved in motor preparation and sensorimotor integration. Specifically, practice-related enhancement of movement-related ERPs supports experience-dependent alterations in the network subserving motor preparation.
学习新的视觉运动任务需要精确处理和转换传入的感觉信息,以产生准确的运动反应。本研究描述了在新的视觉运动学习过程中与感觉运动过程相关的神经活动。我们假设视觉运动技能的习得将伴随着感觉运动皮层活动的经验依赖性调节。受试者用操纵杆控制电脑屏幕上的光标。目标是在短暂延迟后将光标移动到提示目标,操纵杆和光标运动之间的关系,使操纵杆运动控制光标速度,而不是位移(速率任务)。该任务中的单个试验进一步分为早期(速率1)和晚期(速率2)阶段。对目标呈现、运动提示和运动开始时的事件相关电位(ERP)进行平均。与早期速率1阶段相比,受试者在晚期速率2阶段练习后更准确。练习后,与运动开始相关的ERP在中央顶叶部位的振幅更大且出现更早。相比之下,对运动提示的ERP最初在额中央部位增强,并随着练习而减弱。结果表明,在新的视觉运动任务上的练习与参与运动准备和感觉运动整合的额顶叶网络的变化有关。具体而言,与运动相关的ERP的练习相关增强支持了在服务于运动准备的网络中经验依赖性的改变。