Boston University, Brain and Vision Research Laboratory, Boston, MA 02215, USA.
Neurosci Lett. 2011 May 16;495(2):102-6. doi: 10.1016/j.neulet.2011.03.048. Epub 2011 Mar 31.
We describe psychophysical performance of two stroke patients with lesions in distinct cortical regions in the left hemisphere. Both patients were selectively impaired on direction discrimination in several local and global second-order but not first-order motion tasks. However, only patient FD was impaired on a specific bi-stable motion task where the direction of motion is biased by object similarity. We suggest that this bi-stable motion task may be mediated by a high-level attention or position based mechanism indicating a separate neurological substrate for a high-level attention or position-based mechanism. Therefore, these results provide evidence for the existence of at least three motion mechanisms in the human visual system: a low-level first- and second-order motion mechanism and a high-level attention or position-based mechanism.
我们描述了两位左半球不同皮质区域病变的脑卒中患者的心理物理学表现。这两位患者在几个局部和全局的二阶运动任务中，但不是在一阶运动任务中，均表现出对方向辨别能力的选择性损伤。然而，只有患者 FD 在一个特定的双稳态运动任务中受到影响，该任务中运动的方向受到物体相似性的影响。我们认为，这种双稳态运动任务可能是由一个高级注意力或基于位置的机制介导的，这表明存在一个用于高级注意力或基于位置的机制的独立的神经学基础。因此，这些结果为人类视觉系统中至少存在三种运动机制提供了证据：一种低级的一阶和二阶运动机制，以及一种高级的注意力或基于位置的机制。
