The functions and roles of parallel motion processes

认为人类视觉系统存在两种不同的视觉运动机制，它们的最敏感速度不同。然而，极慢运动的机制，以及它与快运动的相互作用还不清楚。我们在心理物理学和功能磁共振成像方法中使用方向选择性适应技术，并在心理物理学中使用掩蔽技术来解决这些问题。心理物理学结果表明，存在两个不同的运动系统，具有不同的时空调谐。功能磁共振成像结果表明，这两个运动系统存在于不同的视觉区域：MT+的第一运动系统和V4的慢运动系统。我们还研究了日常生活中视网膜的时空刺激。结果表明，与静止状态相比，运动状态下的刺激有向高时间频率扩展的趋势。这些结果可能表明，这两种不同的运动系统存在于不同的皮质部位，并为不同的功能工作。

Human visual system is suggested to have two kinds of visual motion mechanisms that differ in their most sensitive velocity. However, the mechanisms of very slow motion, and its interaction with the fast motion are unclear. We addressed these issues with a direction selective adaptation technique in both psychophysical and fMRI methods, and with a masking technique in psychophysics.Psychophysical results showed that there are two different motion systems with different spatiotemporal tunings.fMRI results showed that the two motion systems exist in different visual areas: first motion system in MT+ and slow motion system in V4.We also investigated the spatiotemporal stimulation on retina in everyday life. The results showed tendency that the stimulation extends to high temporal frequencies when people are moving comparing with when people are immobile. These results may indicate that the two different motion systems exist at different cortical sites and works for different functions.