Neuroscientists at Brown University’s Carney Institute for Brain Science studied how parts of the brain must work together to focus on important information while filtering out distractions. The new study provides the most detailed insights yet into brain mechanisms that help people pay attention amid distraction, and what’s happening when they can’t focus. The team’s research, published in Nature Human Behaviour, shows how the brain coordinates these two critical functions.
Lead author and neuroscientist Harrison Ritz likened the process to how humans coordinate muscle activity to perform complex physical tasks, “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.”
The study highlights how people use their powers of attention and what makes attention fail,” said co-author Amitai Shenhav, an associate professor in Brown’s Department of Cognitive, Linguistic and Psychological Sciences. “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. They can also help us better understand limitations on that flexibility, and how limitations might manifest in certain attention-related disorders such as ADHD.”
To conduct the study, cognitive tasks were given to participants while measuring their brain activity in an fMRI machine. Participants saw a swirling mass of green and purple dots moving left and right, like a swarm of fireflies. The tasks varied in difficulty and involved distinguishing between the dots’ movements and colors. The team then analyzed participants’ brain activity in response to the tasks.
In the study, the anterior cingulate cortex tracks what’s going on with the dots. When the anterior cingulate cortex recognizes that motion is making the task more difficult, it directs the intraparietal sulcus to adjust the filtering to reduce the sensitivity to motion. It might direct the intraparietal sulcus to adjust focusing to increase the sensitivity to color so that the relevant brain regions are less sensitive to motion and more sensitive to the appropriate color, and the participant can better make the correct selection. This highlights the importance of mental coordination over mental capacity, revealing an often-expressed idea as a misconception.
“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.”
