Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

The ability to see objects in motion is a fundamental aspect of vision in all animals. My long-term research goal is to understand how the perception of motion is achieved by the human brain. Motion perception develops over time with maturation. Thus, to understand normal motion perception, I study typical and atypical types of visual development. In humans, it is rare to have no ability to perceive motion, but certain conditions affect the ability to perceive specific types of motion. The development of motion perception in children also differs for each of the different types.

It is common to interpret perceptual abilities in terms of the underlying pathways or streams in the brain. Typically, form and colour perception are linked to the ventral stream and motion perception to the dorsal stream. A popular suggestion, based on the prevalence of problems with motion perception in people with developmental disorders, is that the dorsal stream is more vulnerable to damage during childhood than the ventral stream. However, the dorsal/ventral view of visual processing is too simplistic, and more recent evidence implicates the ventral stream in motion perception, at least for slow speeds. This brings into question the usefulness of the notion of dorsal stream vulnerability.

In the next 5 years, the short-term goal of my program is to address this controversy by identifying the brain regions involved in processing different types and speeds of motion using two non-invasive techniques. 1) We will use computer "games", with rigorous behavioural testing (psychophysics), to measure the ability to perceive different types of motion. 2) At the same time, we will use functional magnetic resonance imaging (fMRI) to confirm the brain regions involved in processing different types of motion.

We will determine the typical maturation of different types of motion perception during childhood and adolescence (age 3 to 17 years), with a focus on the role of specific stimulus parameters such as the speed of the motion. To assess the vulnerability of the motion pathways, we will use psychophysics and fMRI to measure changes in motion perception caused by atypical development (e.g., lazy eye, dyslexia, prematurity).

The approach of my lab is unique in that we use both typical and atypical development to understand normal mechanisms of human motion perception, and we synthesize information obtained from psychophysical and fMRI techniques adapted for use with children. Our work will provide new knowledge to challenge existing models of motion perception and help resolve some current controversies. We will develop software tools and research paradigms that can be shared with other researchers, and we will provide normative data for future studies. There will be practical implications for individuals with visual problems caused by neural disorders or brain injury.