Neuroscience Study Reveals Why We Get Distracted

Why do we get distracted?

Whether you’re trying to hold a conversation at a busy restaurant or read on a crowded train, our brains sometimes struggle to pay attention. And while that might be annoying in our fast-paced society, getting easily distracted may actually be a side effect of a more complex brain.

Previous research has shown that our brains can control how much we focus on certain information cues and how much we filter out. Now, neuroscientists from Brown University’s Carney Institute for Brain Science have published a research paper that reveals the complex process by which the brain coordinates between these two critical functions.

“In the same way that we bring together more than 50 muscles to perform a physical task like using chopsticks, our study found that we can coordinate multiple different forms of attention in order to perform acts of mental dexterity,” said Harrison Ritz, who conducted the study while a Ph.D. student at Brown, in a statement.

To conduct the study, published in the journal Nature Human Behavior, participants were asked to perform a range of cognitive tasks while their brain activity was measured using an fMRI machine. The tasks involved watching a swirling mass of green and purple dots, and participants were asked to distinguish between the movement and colors of the dots.

In one task, participants were given a scenario with equal numbers of green and purple dots, but some of the dots were moving much faster than others. Participants were then asked to decide which color represented a larger proportion of the fast-moving dots.

Ritz and Amitai Shenhav, an associate professor in Brown’s Department of Cognitive, Linguistic and Psychological Sciences, explained how two key areas of the brain worked together during this task. They are the intraparietal sulcus, which is involved in attention and manipulation of information in working memory, and the anterior cingulate cortex, which is involved in decision-making, learning and motivation.

“You can think about the intraparietal sulcus as having two knobs on a radio dial: one that adjusts focusing and one that adjusts filtering,” Ritz said. “In our study, the anterior cingulate cortex tracks what’s going on with the dots. When the anterior cingulate cortex recognizes that, for instance, motion is making the task more difficult, it directs the intraparietal sulcus to adjust the filtering knob in order to reduce the sensitivity to motion.”

In the scenario where the purple and green dots are almost at 50/50, he said, it might also direct the intraparietal sulcus “to adjust the focusing knob in order to increase the sensitivity to color. Now the relevant brain regions are less sensitive to motion and more sensitive to the appropriate color, so the participant is better able to make the correct selection.”

Ritz said that these findings challenged a common misconception about the human brain and concentration.

“When people talk about the limitations of the mind, they often put it in terms of ‘humans just don’t have the mental capacity’ or ‘humans lack computing power,'” Ritz said. “These findings support a different perspective on why we’re not focused all the time. It’s not that our brains are too simple, but instead that our brains are really complicated, and it’s the coordination that’s hard.”

Shenhav added that the findings provide insights into the biological basis of attention and what happens when that attention fails.

“These findings can help us to understand how we as humans are able to exhibit such tremendous cognitive flexibility—to pay attention to what we want, when we want to,” he said. “They can also help us better understand limitations on that flexibility, and how limitations might manifest in certain attention-related disorders such as ADHD.”