"The research provides new insights into how the brain controls movements, which helps explain the impulsivity of people with attention deficit and hyperactivity disorder," study co-author Jeffrey Schall, E. Bronson Professor of Neuroscience at Vanderbilt University, said. "It also shows how mathematical models can be used to discover how the brain produces thought and action."
Vanderbilt psychologists Leanne Boucher, Thomas Palmeri, Gordon Logan and Schall published the findings in the April issue of Psychological Review.
The new paper uses physiological data collected in Schall’s laboratory to show how a theoretical model Logan developed more than 20 years ago is implemented by the brain.
"I developed the race model to explain behavior on a task called the stop signal task with a friend of mine, William Cowan, who is a theoretical physicist, in the 1980s," Logan, Centennial Professor of Psychology, said. Stop signal tasks measure an individual’s ability to stop a planned action, like pressing a key on a keyboard or looking at a target, in response to a signal. "Our race model proposed that two independent processes were underway, one telling us to ‘go?and one telling us to ‘stop?in response to the stop signal.
"Applying the model to children’s behavior revealed that stop signal task times are significantly longer in children with attention deficit and hyperactivity disorders than in other children," he said.
The model has been widely accepted and has also been used to explain cognitive problems in people with obsessive-compulsive disorder, schizophrenia and Parkinson’s disease.
"We think of people who are impulsive as acting too quickly," Logan said. "Kids w