Researchers at the University of Iowa in a new study have linked a region in the brain to how humans redirect thoughts and attention when distracted. The connection is important because it offers insights into cognitive and behavioral side effects to a technique being used to treat patients with Parkinson's disease.

The subthalamic nucleus is a pea-sized brain region involved in the motor-control system, meaning our movements. In people with Parkinson's disease, those movements have been compromised: Researchers believe the subthalamic nucleus, which normally acts as a brake on sudden movement, is exerting too much influence. That overactive brake, researchers think, is what contributes to the tremors and other motor deficiencies associated with the disease.