[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/elliott_digby.jpg” caption=”Digby Elliott. Photo credit: Chantall Van Raay”]Reaching for that cup of coffee in the morning may seem to be an effortless task you don't think twice about doing. That reach however takes much more brainpower than one would think. Simple tasks like reaching, grasping, and aiming are not easy for everyone; some people are not co-ordinated enough to grasp that cup of coffee without spilling it over, while others could probably do it with their eyes closed. Why we are able to reach, grasp, throw, and catch effectively are things McMaster's professor Digby Elliot is looking at in his research.

Elliott is trying to understand how people are able to move their upper limbs effectively and efficiently. A professor of kinesiology at McMaster University since 1982, Elliott's research focuses on the visual and motor control of upper limb movements and how they are connected to the brain. He describes his research as a hobby. “I like being able to research because I don't need a hobby. This is my hobby, what I am passionate about,” says Elliott. Elliott holds a Canada Research Chair in Motor Control and Special Populations, and is funded in part by the Natural Sciences and Engineering Research Council of Canada (NSERC).

Elliott is interested in the distinct role of two main visual pathways in the brain. One is more important for visual control of action, which is referred to as the dorsal pathway. The other is more important for cognitive recognition, which is called the ventral pathway. Both are important but in different ways. Elliott gives the example: “If you were sitting in the bar, you would use your ventral to distinguish your drink from others, but use the dorsal to reach for your drink.”

To look at the motor movements in the upper limbs, Elliott and his research team use opto-electric technology to trace the body movements. Some of the experiments only require the researcher to place a single sensor on a person's finger. A projector then flashes targets onto a black surface on a table in front of where the participant is sitting. The participant has to intercept the targets with their finger that has the marker on it as accurately as possible.

In other experiments Elliott tracks the position of multiple sensors at the same time. “We place markers on various body parts that we want to trace, and it tracks where it is in three dimensional space,” says Elliott. “We use the information to make inferences on what's going on in the nervous system.”

Elliott also creates obstacles to see how and why they create a difference in our movements. By creating these obstacles Elliott can manipulate the kind of visual information he wants to examine. One way to do this is by what Elliott refers to as 'blinding' the participants with opaque goggles and switching their vision from one eye to another, like winking. Elliott also moves the target to see how rapidly the nervous system can adjust to the movement. The way the participants change their path to get to the object due to these obstacles can tell Elliott how we are able to adjust our movements to compensate for change.

“The visual and motor areas are intimately connected,” says Elliott. This is because you need your brain to recognize an object and then use the recognition to move to that object. One device he uses is a transcranial magnetic stimulator, which can be used to stimulate the motor areas of the brain when a person is preparing to make a movement. This device can be used to examine changes in the excitability of the areas of the cortex responsible for upper limb movements.

These experiments help to tell how our nervous system functions and why we are able to reach for the cup of coffee and perform other motor movements. Elliott describes it as a “simple model of speed accuracy.” He looks at things like how a person's performance changes with practice. For instance, why we can close our eyes and be accurate on reaching an object we know is there but can't see. Elliott looks at if there is an improvement with time and part of his research is to find out how and why that is realized.

Elliott however does not only look at people who are typically developed. He has broadened his research over the past 15 years to working more and more with people who have developmental problems. This started in his graduate work when he was working with developmentally challenged people.

He is looking at why it is harder for people with a disability to aim, reach, and throw than it is for a person who is typically developed and what the differences are. In his research, he focuses on children and adults who have Down syndrome, autism and Williams syndrome.

Elliott looks at all these developmental problems differently and in their own context. Each group exhibits a different type of developmental problem that constrains perceptual-motor planning, co-ordination or limb control.

Williams syndrome is not very common, and it is usually more difficult to find test subjects. “Williams syndrome is a chromosomal disorder, only one in every 20,000 people have it,” says Elliott. “One hypothesis about it is that they are 'dorsal deficient' so they are clumsy, and have trouble with regulating movement.” One of their major problems may be related to the visual control of movement.

Conversely, those with Down syndrome “seem to rely on 'online control,' that is they do not engage in the same degree of advance planning as typically developed people would,” Elliott says. It is apparent from his research that people with Down syndrome haven't planned their movement as accurately; they have to do extra thinking en route to the target they are trying to reach.

In autism, there is also trouble in the movement planning, but much of it has to do with not just the cognitive problems but also with the social problems autistic people face. These are problems that arise from not being able to interact with the world in the same manner as other people do.

One goal for Elliott is to determine how people with development disabilities use visual and other information to control their movements. This will help in developing instructional programs and structuring the education environment. “For example people with Down syndrome have more trouble using verbal than visual information in learning new motor skills,” Elliott says.

However, an ultimate goal for Elliott is to determine how the nervous system works in people who are developmentally challenged. “I want to find out how their nervous system is working differently and then apply knowledge to perception-motor learning,” Elliott says. With that knowledge, Elliott can help them perform and do everyday tasks like picking up a cup of coffee and teach them how to do these tasks accurately and effectively.

With his research, Elliott can help create an understanding of how and why the nervous system works in controlling upper limb movements. His research also is creating an awareness and education for people who are not as typically developed and in doing so it shines new light on helping them improve their own motor skills.

(The Natural Sciences and Engineering Research Council SPARK (Students Promoting Awareness of Research Knowledge) program was launched in 1999 at 10 universities across Canada. Through SPARK, students with an aptitude for communications are recruited, trained and paid to write stories based on the NSERC supported research at participating universities.)