Human brain adapts to minimize distractions
New research on neuronal connections has potential to aid stroke recovery
Our brains are making a million decisions a minute, most of which we are only minimally aware of. But in order for us to function efficiently, our brains must also make decisions about what is most important at any particular moment. A study by UC Davis researchers has found that the brain determines importance based on our current situation and reconfigures the connections between neurons to minimize any distractions.
“In order to behave efficiently, you want to process relevant sensory information as fast as possible,” said Joy Geng, an assistant professor of psychology at the UC Davis Center for Mind and Brain (CMB). “We have a limit in the number of things we can process at once. It is not useful to process everything in parallel with validity.”
The research found that when we are concentrating on a specific task, it benefits us to reconfigure the network between neurons so that task-relevant information is processed more efficiently. This process, commonly thought of as ramping up your thought process, is in fact more similar to opening an instant chat window between two people; there are other ways to communicate like e-mail, texting or calling, but the instant chat allows two people to communicate immediately back and forth, faster than the other methods will allow.
In effect, this process alters the path that signals take to and from different parts of the brain. For people suffering from localized brain damage, such as from a stroke, these pathways can be interrupted. Finding new pathways can help with rehabilitation for these patients.
To discover this neural process, the researchers used functional magnetic resonance imaging (fMRI) to measure the changes in blood flow to certain parts of test subjects’ brains while they performed a test. Increased blood flow to a particular region indicated increased neuronal activity.
Subjects were instructed to look at a screen and indicate whether the “T” that appeared on screen was oriented up or down. To test the ability to cope with distractions, a “salient” (distracting) object would be displayed along with the T. This salient object would be brighter or bigger. The researchers then tested the reaction time to indicate the orientation of the target object with and without the distraction object.
“We displayed something that you would think would be distracting, but the brain was able to cope,” said Nick DiQuattro, a graduate student working with Geng at the CMB. “The brain was able to reject the distraction and focus on the target.”
“It is interesting because [we] can reshape the way we think about how we process information,” Geng said. “The brain is constantly being put into different contextual states.”
An example of this phenomenon that we commonly experience is that while we are driving, flashing lights or signs alert us to stop, or that traffic is merging, or many other things. Our brain is thinking in the context of driving, so these “attention-getters” are processed quicker than they would be if we were in a different contextual state.
It is important not to confuse this process with the fight-or-flight response, which deals with responding to surprising stimuli, rather than changing the reactions based on context.
According to a National Institutes of Health study, there are close to 750,000 strokes every year, many of which lead to mild, or even extreme, brain damage. With this new understanding of the brain’s connection methods, researchers hope that patients in stroke recovery will have a much better chance of regaining much of their lost cognitive functions.