Research Overview
My main area of research is directed at understanding the neural correlates underlying perceptual-motor and social-emotional processing in children and adults with and without developmental disabilities. I use a combination of behavioural measures and brain imaging tools (i.e. Magnetoencephalography) in my research.
Current Research Projects:
Concussion in Youth Hockey: New Frontiers in Diagnostic Imaging
Sports related concussion has become a “hot topic” both in the media and in medicine. Recent research is beginning to reveal the extent and nature of the long-term consequences of concussion. The risk of injury in young athletes is of particular concern as the brain is still developing through childhood and into adolescence and may be more susceptible to trauma.
One of biggest issues following a sport related concussion is the decision to return to play. Currently, physicians base this decision on neurological examination, symptoms and standardized assessments of cognitive function. While these examinations and tools have been useful, the underlying impact on the structure and function of brain is still unknown. Standard neuroimaging, such as CT and MRI, have not been able to readily identify changes in the brain after concussion. In the last few years, there have been some exciting new developments in imaging technology. New tools to assess brain functions are emerging that may provide a more accurate picture of the brain following injury and help predict recovery.
The overall purpose of this project is to develop imaging “signatures” of concussion. We will combine two cutting edge brain imaging tools – A magnetic resonance imaging (MRI) technique called diffusion tensor imaging (DTI) and magnetoencephalography (MEG) to capture the changes in the microstructure of the brain and the underlying activity of brain networks in young elite hockey players who have sustained a concussion. Combining these techniques with behavioural assessment has never been applied to study the impact of paediatric concussion on the brain. This work will provide new insights into the impact of concussion on the structure and function of the developing brain.
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| Concussion in Youth Hockey Info sheet |
Mirrors in the Brain
Humans have a remarkable ability to understand the actions and intentions of other people, and to imitate these same actions. How we understand and interpret the actions and an emotion of others has been a central question in neuroscience. Advances in neuroscience in the last decade have led to the discovery of new class of brain cells called mirror neurons. These cells not only fire when we perform an action but also when we watch someone else performing the same action. This discovery has generated tremendous excitement as some scientists speculate that the mirror neuron system may form the basis of our social behaviour, our ability to imitate, acquire language and show empathy. The question we asked is whether this system is intact in individuals with Down syndrome. Results from our work indicate that although there is a link between perception and action in individuals with DS, the mirror neuron system may not function in the same way as in typical individuals. We are now in the process of designing research studies to investigate whether targeted “observation intervention” can cause changes in the underlying activation patterns in the brain.
Virji-Babul, N., Moiseev, A., Cheung, T., Weeks, D., Cheyne, D., Ribary, U. (2010). Spatial-temporal dynamics of cortical activity underlying reaching and grasping: Implications for understanding the mirror neuron system. Human Brain Mapping. 31, 1: 160-171.
Perception of Motion and Emotion
Social behavior depends upon inferences that are based on the perception and interpretation of other people’s actions and emotions. Given the fundamental importance of accurately perceiving socially relevant information, we are studying how children and adults (with and without DS) perceive this information. We present short video clips showing animations of people performing different actions or portraying a variety of emotional expressions in the movement of their bodies. We are currently investigating how the underlying patterns of brain activity are modulated by the emotional content of the actions.
Cortical dynamics in children with developmental disabilities
A theme emerging from recent brain imaging studies is that there are common patterns of altered communication in distributed cortical networks underlying both spontaneous activity and those involved in perception, cognition and action across a range of developmental disabilities. Such altered resting network dynamics have been reported in autism, Down syndrome and in very pre-term children. In addition, there appear to be commonalities in brain dynamics underlying action observation and action execution in autism and Down syndrome. I will be starting a new project to determine whether there are common disturbances of cortical dynamics expressing overlapping patterns of functional impairment across three specific developmental disabilities: autism, cerebral palsy and Down syndrome.
Music perception in adults with Down syndrome
Individuals with Down syndrome reportedly have a strong interest in music and are noted for their aptitude in rhythm and movement/dance. Given the link between auditory and motor interactions, we have recently started a project to study the brain responses to familiar (“Mamma Mia) vs unfamiliar music (Bach) in adults with and without Down syndrome.
Aging in Down Syndrome: A Model for Preclinical Alzheimer's Disease
Postmortem studies show that at 40 years of age, almost all subjects with DS have neuropathological changes that meet the pathological criteria for AD. These changes include extensive cerebral atrophy, accumulation of ßamyloid, extracellular senile plaques and intracellular neurofibrillary tangles in the hippocampus and frontal and temporal cortices. DS is therefore an extremely useful model to study the preclinical stages of AD as middle aged individuals can be identified prior to any clinical signs of dementia. Our goal is to use MEG data to compute measures of functional connectivity that may be useful in predicting the onset of dementia.
Training Opportunities
I am recruiting MSc and PhD trainees with a background either in pediatrics, neuroscience and/or biomedical engineering. Potential projects will involve both behavioural and brain imaging studies using EEG and/or MEG in both pediatric and adults populations.
