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。我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。一个人完全缺乏感知运动的能力是罕见的，但某些发育障碍会影响感知特定类型运动的能力。此外，儿童运动知觉的发展因不同类型的运动而异。我们研究典型和非典型的视觉发展，以澄清运动知觉的正常机制。我们通常会根据大脑中的潜在通路或流来解释我们的研究类型。形状和颜色感知通常与腹侧流有关，而运动感知则与背侧流有关。有人认为，背侧流在儿童时期比腹侧流更容易受到损害。然而，背侧/腹侧视觉处理的观点可能过于简单化，最近的证据表明，腹侧流在慢速运动感知中起作用。这使背流脆弱性概念的有用性受到质疑。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。通过一种被称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。通过功能性磁共振成像（MRI），将确定儿童观看不同类型运动时大脑活动变化的区域。我们的方法是独特的结合信息的典型成熟的运动知觉的儿童（3至17岁）的信息所造成的弱视，阅读障碍或早产的运动知觉的变化，并在这些人群中的心理物理和功能性MRI数据的链接。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。这将对加拿大儿童和成人因神经紊乱或脑损伤而出现视力问题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.