Researchers led by the University of California, Davis, reveal the brain first targets broad categories of anticipated objects and then focuses on specifics. Findings suggest implications for treating conditions like ADHD and autism.
How does our brain prioritize what we see? A recent study led by researchers at the University of California, Davis, has provided fresh insight into how the brain coordinates visual attention.
The findings, published in The Journal of Neuroscience, help us understand that our brains initially focus on broad features before narrowing in on specific details.
“Our study tells us that our brains first prepare to focus attention by activating neurons representing the broad category of the anticipated object and then quickly sharpens that focus,” George R. Mangun, a distinguished professor of psychology and neurology and co-director of UC Davis’ Center for Mind and Brain. “This means that the brain’s attention mechanisms are organized in a hierarchy such that it prepares for perceiving a stimulus by narrowing the focus of our attention over time.”
Clocking Brain Activity
Using a combination of electroencephalogram (EEG), eye tracking and machine-learning methods, the study investigated “anticipatory attention” — the kind of attention that gets us ready to perceive upcoming sensory events.
The researchers observed 25 participants, aged 19 to 39, and recorded down-to-the-millisecond electrical activity through EEG sensors attached to the scalp.
During the experiment, participants were instructed to focus on colored dots moving on a screen, either by color (blue or green) or direction of movement (up or down).
“The control systems involved in attention are broadly tuning the brain first, and then narrowing it down. It’s like a pilot flying a plane toward Europe and then toward the end zooming in on Rotterdam and not Berlin,” Mangun added.
Fine-Tuning Focus
The study revealed that focusing on a broad category, such as an object’s color or movement direction, took approximately 240 milliseconds. However, honing in on specific details — like identifying which specific color or direction — extended to 400 milliseconds.
“When attention is directed to the color of the moving dots, it suppresses attention to the direction of motion, and vice versa,” added lead author Sreenivasan Meyyappan, an assistant project scientist at the Center for Mind and Brain. “This broad focus of attention is then narrowed further to suppress the irrelevant colors as well, supporting processing of the specific color or motion of interest.”
Potential Implications
Understanding the subtleties of how our brain’s attention mechanisms work could have significant implications for neurological and psychological health. For example, insights from this research might aid in developing new treatment methods for attention disorders such as ADHD or autism.
“Understanding more about how the brain focuses its attention would tell us what parts of the system are not operating properly and might lead to different perceptual or behavioral symptoms down the line, and therefore different treatment approaches” Mangun added.
Mingzhou Ding, a distinguished professor and the J. Crayton Pruitt Family Professor of biomedical engineering at the University of Florida, co-authored the study.
Source: University of California, Davis