Department of Neurology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
Proc Natl Acad Sci U S A. 2010 Jan 19;107(3):1229-34. doi: 10.1073/pnas.0910742107. Epub 2009 Dec 28.
We continuously move our eyes when we inspect a visual scene. Although this leads to a rapid succession of discontinuous and fragmented retinal snapshots, we perceive the world as stable and coherent. Neural mechanisms underlying visual stability may depend on internal monitoring of planned or ongoing eye movements. In the macaque brain, a pathway for the transmission of such signals has been identified that is relayed by central thalamic nuclei. Here, we studied a possible role of this pathway for perceptual stability in a patient with a selective lesion affecting homologous regions of the human thalamus. Compared with controls, the patient exhibited a unilateral deficit in monitoring his eye movements. This deficit was manifest by a systematic inaccuracy both in successive eye movements and in judging the locations of visual stimuli. In addition, perceptual consequences of oculomotor targeting errors were erroneously attributed to external stimulus changes. These findings show that the human brain draws on transthalamic monitoring signals to bridge the perceptual discontinuities generated by our eye movements.
当我们观察一个视觉场景时，我们的眼睛会不断移动。尽管这导致了视网膜连续快照的快速连续和不连续，但我们感知到的世界是稳定和连贯的。视觉稳定性的神经机制可能依赖于对计划或正在进行的眼球运动的内部监测。在猕猴大脑中，已经确定了一种用于传递此类信号的途径，该途径由中央丘脑核中继。在这里，我们研究了该途径在一名选择性损伤影响人类丘脑同源区域的患者中对感知稳定性的可能作用。与对照组相比，该患者表现出对眼球运动监测的单侧缺陷。这种缺陷表现为连续眼球运动和判断视觉刺激位置的系统不准确性。此外，眼球运动靶向错误的知觉后果被错误地归因于外部刺激变化。这些发现表明，人类大脑利用丘脑间监测信号来弥合我们眼球运动产生的知觉不连续性。
