Brain mechanisms underlying human motion perception

看到运动物体的能力是所有物种视觉的一个基本方面。一个人完全缺乏感知运动的能力是很罕见的，但是某些视觉障碍和某些类型的脑损伤会影响感知特定类型运动的能力。此外，儿童运动知觉的发展在不同类型的运动中存在差异。这项研究的总体目标是了解人类大脑通常是如何实现运动感知的。该提案的具体目标是确定视觉通路的两个分支（称为M/背侧和P/腹侧）在我们对运动的感知中的作用。这项工作将集中在全球运动和运动定义的形式感知。虽然这两种类型的运动在许多方面是相似的，但在阅读障碍、弱视或多发性硬化症等神经疾病中，只有一种倾向于被破坏，这表明可能涉及不同的途径。运动知觉传统上被认为是M/背侧通路的功能，但最近的证据表明P/腹侧通路，特别是在较慢的运动速度。研究对象为：（1）M/背侧通路暂时中断的成人，（2）M/背侧或P/腹侧通路永久性损伤的个体，以及（3）视觉系统发育中的儿童。将使用两种不同的非侵入性技术。通过一种被称为心理物理学的行为技术，计算机“游戏”将被用来测量一个人感知不同类型运动的能力。通过功能性磁共振成像，当一个人观看不同类型的运动时，大脑活动的变化将被用来确定所涉及的视觉通路。我们的方法是独特的，在连接心理物理和功能磁共振成像数据从成人，儿童和个人与脑病变。这项工作将为现有的运动感知模型提供新的挑战，并有助于解决当前的一些争议。对于因神经紊乱或脑损伤而导致视力问题的儿童和成人的治疗和康复也有实际意义。

The ability to see objects in motion is a fundamental aspect of vision in all species. It is rare for a person to totally lack the ability to perceive motion, but certain disorders of vision and certain types of brain damage affect the ability to perceive specific types of motion. In addition, the development of motion perception in children differs across different types of motion. The overall goal of this research is to understand how the perception of motion is normally achieved by the human brain. The specific goal of this proposal is to determine the role of two subdivisions of the visual pathway (referred to as M/dorsal and P/ventral) in our perception of motion. This work will focus on global motion and motion-defined form perception. Although these two types of motion are similar in many ways, the fact that only one or the other tends to be disrupted in neural disorders such as dyslexia, lazy eye or multiple sclerosis, suggests that different pathways may be involved. Motion perception is traditionally considered to be a function of the M/dorsal pathway, but more recent evidence implicates the P/ventral pathway, particularly at slower speeds of motion. Global motion and motion-defined form perception at different speeds will be studied in: (1) adults with temporary disruption of the M/dorsal pathway, (2) individuals with permanent damage to the M/dorsal or P/ventral pathway, and (3) children with developing visual systems. Two different non-invasive techniques will be used. With a behavioural technique called psychophysics, computer "games" will be used to measure a person's ability to perceive different types of motion. With functional magnetic resonance imaging, changes in brain activity while a person watches different types of motion will be used to determine the visual pathways involved. Our approach is unique in linking psychophysical and functional MRI data from adults, children and individuals with brain lesions. This work will provide new challenges for existing models of motion perception and help resolve some current controversies. There will also be practical implications for the treatment and rehabilitation of children and adults with visual problems caused by neural disorders or brain injury.