Ohlendorf Sabine, Sprenger Andreas, Speck Oliver, Glauche Volkmar, Haller Sven, Kimmig Hubert
Department of Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany.
J Vis. 2010 Dec 20;10(14):21. doi: 10.1167/10.14.21.
The ability to pursue moving objects with the eyes is vital to humans. However, it remains unclear how the brain differentiates visual object motion, smooth pursuit eye movements (SPEM), and eye movement-induced relative motion on the retina and where visual-to-oculomotor transformation takes place. To characterize functional differences of SPEM-processing cortical areas, we simultaneously measured functional magnetic resonance imaging (fMRI) and smooth pursuit to visual, oculomotor, and visuo-oculomotor stimuli varying the quantity of background dots of the stimuli. Resulting activations involved the whole visuo-oculomotor network. They varied among regions depending on the functional tasks and parametric changes of the background. Activation in many SPEM regions increased from 1 to 16 background dots but decreased at 36 dots. This could be an effect of coherent-texture perception. Putative MST area was not influenced by the amount of moving or stationary background dots. It probably participates in visuo-oculomotor transformation. Parts of the posterior parietal cortex seem specifically activated with relative motion between eye and background, but not with motion per se. This could be important for the perception of spatial references.
用眼睛追踪移动物体的能力对人类至关重要。然而，大脑如何区分视觉物体运动、平稳跟踪眼球运动（SPEM）以及眼球运动引起的视网膜上的相对运动，以及视觉到动眼神经的转换发生在哪里，目前仍不清楚。为了表征处理SPEM的皮质区域的功能差异，我们同时测量了功能磁共振成像（fMRI）以及对视觉、动眼神经和视觉动眼神经刺激的平稳跟踪，这些刺激改变了刺激的背景点数量。由此产生的激活涉及整个视觉动眼神经网络。它们在不同区域之间有所不同，这取决于功能任务和背景的参数变化。许多SPEM区域的激活从1个背景点增加到16个，但在36个点时减少。这可能是连贯纹理感知的结果。假定的MST区域不受移动或静止背景点数量的影响。它可能参与视觉动眼神经转换。顶叶后部皮质的部分区域似乎在眼睛与背景之间的相对运动时被特异性激活，但不是在运动本身时被激活。这对于空间参照的感知可能很重要。
