Research advances understanding of the human brain
Advanced neuroimaging techniques are giving researchers new insight into how the human brain plans and controls limb movements. This advance could one day lead to new understanding of disease and dysfunction in the brain and has important implications for movement-impaired patient populations, like those who suffer from spinal cord injuries.
Randy Flanagan (Psychology and Centre for Neuroscience Studies), working with colleagues at Western University, used functional magnetic resonance imaging (fMRI) to uncover what regions of the human brain are used to plan hand actions with the left and right arm. This study, spearheaded by Jason Gallivan, a Banting postdoctoral fellow at Queen’s, found that by using the fMRI signals from several different brain regions, they could predict the limb to be used (left vs. right) and hand action to be performed (grasping vs. touching an object), moments before that movement is actually executed.
“We are trying to understand how the brain plans actions,” says Dr. Gallivan. “By using highly sensitive analysis techniques that enable the detection of subtle changes in brain activity patterns, we can reveal which of a series of actions a volunteer is merely intending to do, seconds later. Mapping and characterizing these predictive signals across the human brain allows us to pinpoint the key brain structures involved in generating normal, everyday behaviours.”
In another study, Dr. Flanagan and doctoral student Jonathan Diamond examined how the brain learns object mechanical properties, knowledge that is essential for skilled manipulation. They found that, through experience, humans use mismatches between predicted and actual fingertip forces and between predicted and actual object motions to build internal representations, or models, of the mechanical properties of the objects.
“The goal of this work is to understand the representations underlying skilled manipulation,” explains Dr. Flanagan. “This is important because it will enable us to better characterize deficits in manipulation tasks that often result from stroke and neurological diseases.”
Dr. Flanagan, Dr. Gallivan, and Ingrid Johnsrude (Psychology and Centre for Neuroscience Studies) have recently been awarded a CIHR operating grant to support ongoing neuroimaging work.