Brain Mechanisms Underlying Human Motion Perception

能够看到运动中的物体是所有物种视觉的一个基本方面。我研究的总体目标是了解人脑通常是如何实现对运动的感知的。一个人完全缺乏感知运动的能力是很少见的，但某些发育障碍会影响感知特定类型运动的能力。此外，不同类型的运动对儿童运动知觉的发展有不同的影响。我们研究典型的和非典型的视觉发展来阐明运动知觉的正常机制。根据大脑中潜在的通路或流来解释我们的研究类型是很常见的。形状和颜色知觉通常与腹侧流有关，运动知觉与背侧流有关。有人认为，在儿童时期，背侧流比腹侧流更容易受到损害。然而，视觉加工的背侧/腹侧视角可能过于简单化，而且最近的证据表明，腹侧流在慢速时的运动知觉中涉及。这让人质疑后向流脆弱性概念的用处。这项提案的具体目标是通过使用两种非侵入性技术识别参与处理快动作和慢动作的大脑区域来解决这一争议。通过一种名为心理物理学的行为技术，计算机“游戏”将被用来测量儿童感知不同类型运动的能力。通过功能磁共振成像(MRI)，可以确定当儿童观看不同类型的运动时，大脑活动发生变化的区域。我们的方法是将有关儿童(3至17岁)运动知觉典型成熟的信息与懒眼、阅读困难或早产导致的运动知觉变化的信息结合起来，并将这些人群的心理物理和功能MRI数据联系起来。这项工作将对现有的运动感知模型提出新的挑战，并有助于解决当前的一些争议。这将对加拿大因神经障碍或脑损伤导致视力问题的儿童和成人的治疗和康复产生实际影响。

The ability to see objects in motion is a fundamental aspect of vision in all species. The overall goal of my research is to understand how the perception of motion is normally achieved by the human brain. It is rare for a person to totally lack the ability to perceive motion, but certain developmental disorders affect the ability to perceive specific types of motion. In addition, the development of motion perception in children differs for different types of motion. We study typical and atypical visual development to clarify normal mechanisms of motion perception. It is common to interpret our type of research in terms of the underlying pathways or streams in the brain. Form and colour perception are typically linked to the ventral stream and motion perception to the dorsal stream. It has been suggested that the dorsal stream is more vulnerable to damage during childhood than the ventral stream. However, the dorsal/ventral view of visual processing is probably too simplistic, and more recent evidence implicates the ventral stream in motion perception for slow speeds. This brings into question the usefulness of the dorsal stream vulnerability idea. The specific goal of this proposal is to address this controversy by identify the brain regions involved in the processing of fast and slow motion using two non-invasive techniques. With a behavioural technique called psychophysics, computer "games" will be used to measure a child's ability to perceive different types of motion. With functional magnetic resonance imaging (MRI), regions where brain activity changes while a child watches different types of motion will be determined. Our approach is unique in combining information about the typical maturation of motion perception in children (3 to 17 years old) with information about the changes in motion perception caused by lazy eye, dyslexia or preterm birth, and in the linking of psychophysical and functional MRI data in these populations. This work will provide new challenges for existing models of motion perception and help resolve some current controversies. There will be practical implications for the treatment and rehabilitation of Canadian children and adults with visual problems caused by neural disorders or brain injury.