Experimental and Biological Psychology, Philipps-University Marburg, Germany.
Neuroimage. 2011 Feb 1;54(3):2401-11. doi: 10.1016/j.neuroimage.2010.09.080. Epub 2010 Oct 23.
Event-related functional magnetic resonance imaging was applied to identify cortical areas involved in maintaining target information in working memory used for an upcoming grasping action. Participants had to grasp with their thumb and index finger of the dominant right hand three-dimensional objects of different size and orientation. Reaching-to-grasp movements were performed without visual feedback either immediately after object presentation or after a variable delay of 2-12 s. The right inferior parietal cortex demonstrated sustained neural activity throughout the delay, which overlapped with activity observed during encoding of the grasp target. Immediate and delayed grasping activated similar motor-related brain areas and showed no differential activity. The results suggest that the right inferior parietal cortex plays an important functional role in working memory maintenance of grasp-related information. Moreover, our findings confirm the assumption that brain areas engaged in maintaining information are also involved in encoding the same information, and thus extend previous findings on working memory function of the posterior parietal cortex in saccadic behavior to reach-to-grasp movements.
事件相关功能磁共振成像被应用于识别在用于即将进行的抓握动作的工作记忆中维持目标信息的皮质区域。参与者必须用他们的右手拇指和食指抓取不同大小和方向的三维物体。伸手抓握动作要么在物体呈现后立即进行，要么在 2-12 秒的可变延迟后进行。在整个延迟过程中，右下顶叶皮层表现出持续的神经活动，与抓取目标编码期间观察到的活动重叠。即时和延迟抓取激活了相似的与运动相关的大脑区域，没有表现出差异活动。研究结果表明，右下顶叶皮层在抓握相关信息的工作记忆维持中起着重要的功能作用。此外，我们的发现证实了这样一种假设，即维持信息的大脑区域也参与了对相同信息的编码，从而将关于后顶叶皮层在扫视行为中工作记忆功能的先前发现扩展到伸手抓握动作。
