Their study is published today in the journal Nature Neuroscience.
The research team has found that a small region in the frontal lobe of the human brain is selectively activated when an individual intends to make a particular action and not another. These findings help explain why individuals with frontal lobe damage sometimes act impulsively and often have problems making decisions.
“We have identified signals in the normal human brain that we can now investigate in patients with neurological or psychiatric disorders that affect frontal lobe function,” says team member Doug Munoz, professor in the Departments of Physiology and Psychology at Queen’s, and holder of a Canada Research Chair in Neuroscience. “For example, subjects diagnosed with attention-deficit hyperactivity disorder should produce different patterns of brain activation that we can identify. We will then be able to see if these patterns change when they are treated with medication.”
The lead author on the paper is Jason Connolly, a neuroscience graduate student at Western. Other members of the team include Dr. Munoz from Queen’s, and Mel Goodale and Ravi Menon from Western.
The researchers used a new fMRI "single-event" method to study the changes in blood flow in the frontal lobes as volunteers prepared to perform one of two different kinds of movements when a visual target was presented. Not only did the signals in the frontal lobes build up over time as the volunteers got ready to respond, but the nature of the activity varied and depended on whether they were planning to make one kind of movement rather than another.
Future experiments by the research team will explore how these frontal circuits interact with other areas of the brain in the planning and control of everyday behaviour, as well as investigating patient groups.
Journal
Nature Neuroscience