The Multitasking Brain
Study shows neural circuits can rapidly switch tasks
Imagine driving on a dark road. In the distance, you see a single light. As the light approaches, it splits into two headlights. That’s a car, not a motorcycle, your brain tells you.
A new study has found that neural circuits in the brain rapidly multitask between detecting and discriminating sensory input, such as headlights in the distance. That’s different from how electronic circuits work, where one circuit performs a very specific task. The brain, the study found, is wired in a way that allows a single pathway to perform multiple tasks.
“We showed that circuits in the brain change or adapt from situations when you need to detect something versus when you need to discriminate fine details,” said Garrett Stanley, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
The findings were published in the journal NEURON. The research was supported by the National Institutes of Health (NIH) and the National Science Foundation.
“Every day, we are bombarded with sensations, and the brain automatically chooses which ones to detect. This study may help scientists answer fundamental questions about how neurological disorders may disrupt the brain circuits that make those choices,” said Jim Gnadt, program director at the National Institute of Neurological Disorders and Stroke, part of the NIH.
The distance at which a person can discern two headlights from a single light is controlled by the acuity of the body’s sensory pathway. Neuroscientists had assumed that the level of one’s acuity was controlled by the distance between areas in the brain that are triggered by the sensory input. If these two areas of the brain closely overlap, then two sensory inputs – two headlights in the distance – will appear as one, the thinking went.
The new study used animal models and optical imaging to directly assess how acuity is controlled in the brain, and how acuity can adapt to the task at hand. One neuronal circuit can do different things and do them in a robust way, the study found.