"This study underlines the importance of considering the operation of brain circuitry involved even in an ostensibly simple task," said Edith Sullivan, associate professor of psychiatry at Stanford University School of Medicine. "Further, evidence for recruitment of brain regions that are not normally involved in a given task puts a person at risk for performance inefficiency for that particular task, other tasks that need to be done simultaneously, and more complex divided-attention tasks, such as driving."
Higher Brain Activity
Increased activity in the ipsilateral cortical region of the brain was highly unexpected, said Martin."Normally, when I tap with my right hand," he said, "it's mostly my left motor cortex (part of the frontal lobes) that's firing, in conjunction with my right cerebellum. 'Ipsi' means same side, 'contra' means opposite side. So, we're talking about my contralateral cortex and my ipsilateral cerebellum. The significantly higher activity we found in the alcoholics was on the ipsilateral cortex, the side that we don't normally expect to be activated.
"This finding is compatible with the idea that different regions of the brain are being called into activity that would not normally be activated in order to meet the behavioral demands. Furthermore, this suggests that even though alcoholics at some level may seem to be performing normally, if you raised the level of complexity at which they are being asked to perform, they may exhaust their capacities -- there may be no more brain to bring in, to recruit, to compensate."
The Brain Gets Better at Compensating
These findings lead to new questions, said Martin. "If we study patients as they progress with their abstinence, do these abnormalities get better? It may be that the brain gets better at compensating, but it doesn't normalize, it just learns how to bring in even more parts of the brain. You could say it learns to rewire itself."Another possibility could be that as the brain heals, less activation is required, and that's a real form of recovery. The answers rest with understanding not the tapping itself, but the mechanisms behind the tapping."
Source: Vanderbilt University School of Medicine.
