Biomedical Engineering

Virtual reality serving science

Developed in the video game industry in order to make play more realistic, virtual reality can also be used in science. Julie Messier, a new professor in the Department of Kinesiology, understands its potential. She used virtual reality during her post-doctorate in the United States to better understand loss of sensory-motor function in persons suffering from Parkinson’s disease.

Thanks to a grant of close to $400,000 from the Canada Foundation for Innovation, the neuroscientist will have access to virtual reality equipment that will enable her to study sensory-motor malleability in normal and pathological aging—a promising new field of study.

What is meant by sensory-motor malleability? It is the capacity to adapt the movements we make mechanically to pick up and handle objects effectively. “In everyday life,” she explains, “we continually have to perform accurate movements in new situations. But to adapt our movements to these situations, we have to be able to learn. For example, to use an object like a fork or hammer, we have to learn to associate the length of the object with the range of arm movement needed to reach the target: the turkey for the fork, the nail for the hammer. We must also learn to associate the object’s weight with the strength required to hold and move it. The same kind of associations needs to be made when we learn to drive.”

Thanks to our cognitive functions, we already have a visual idea of the shape, size and weight of objects in our surroundings, Julie Messier tells us. When we pick them up, we adjust automatically. “In the case of new objects, when we first handle them we obtain the information we need to manipulate them properly for the next time.”

As people age, the efficiency of sensory-motor functions deteriorates in some individuals, more acutely in persons suffering from neurological disorders such as Parkinson’s, Alzheimer’s or brain injury. The virtual reality equipment Julie Messier plans to use will allow her to disrupt visual and kinesthetic feedback simultaneously when complex tasks are performed in three-dimensional space. As a result, she will be able to create a variety of new situations involving movements that place the same demands on the sensory-motor system as natural situations do.

The virtual reality system consists of three components: a motion analysis system that records the positions and movements of body segments in real time when movements are made in three-dimensional space; a three-dimensional mobile articulated mechanical arm that can mimic the movement of an object in space; and a machine that can create easily manipulable virtual environments.