The breakdown occurs in corpus callosum, a part of the brain that acts as a dam during one-sided motor activities to prevent unwanted connectivity, or cross-talk, between the two halves of the brain, said Rachael Seidler of University of Michigan School of Kinesiology.
The study showed that this cross-talk is not helpful or compensatory for the two halves of the brain to communicate during one-sided motor movements because the opposite side of the brain controls the part of the body that is moving.
So, when both sides of the brain talk simultaneously while one side of the body tries to move, confusion and slower responses result, Seidler said.
In the study, researchers gave joysticks to adults between the ages of 65 and 75 and measured and compared their response times against a group approximately 20-25 years old.
"The more they recruited the other side of the brain, the slower they responded," Seidler said.
Now, the team is working on developing and piloting motor training studies that might rebuild or maintain the corpus callosum to limit overflow between hemispheres, she said.
The study appeared in the journal Frontiers in Systems Neuroscience.(ANI)