UC Davis Study Reveals How the Brain Prioritizes Visual Attention

Research at the University of California, Davis has provided new insights into how the brain prioritizes visual attention. The study, published on August 19, 2024, in The Journal of Neuroscience, explores the mechanisms behind anticipatory attention—how we prepare to perceive objects before they even appear.

The research team from the Center for Mind and Brain analyzed electrical brain activity using advanced machine-learning techniques. Participants were asked to focus on colored dots moving across a screen, enabling researchers to determine whether the brain initially concentrates on broad characteristics, such as movement, or specific features—like the direction of that movement.

George R. Mangun, a Distinguished Professor of psychology and neurology, emphasized the study’s findings: “Our brains first prepare to focus attention by activating neurons representing the broad category of the anticipated object and then quickly sharpens that focus.” This hierarchical organization of attention mechanisms suggests that the brain sequentially narrows its focus to perceive stimuli more efficiently.

Understanding Anticipatory Attention

The research utilized electroencephalogram (EEG) data alongside eye tracking to investigate how quickly the brain can prepare to attend to specific features. EEG captures electrical activity in the brain with millisecond precision, providing a detailed view of cognitive processing.

In this study, 25 participants aged between 19 and 39 were engaged in tasks where they were cued to look for either a blue or green dot or a dot moving in a specific direction. The timer started with a blank screen and concluded when the dots appeared on the screen.

Findings revealed that the brain’s anticipatory attention to a dot’s general category—color or direction of movement—took an average of 240 milliseconds to establish. In contrast, focusing on specific features, such as distinguishing between blue or green or identifying upward or downward movement, averaged 400 milliseconds.

According to Sreenivasan Meyyappan, an assistant project scientist and lead author of the study, “When attention is directed to the color of the moving dots, it suppresses attention to the direction of motion, and vice versa.” This indicates that the brain’s focus is initially broad, then narrows down to filter out irrelevant information, enhancing the processing of specific characteristics.

Implications for Brain Health

The insights gained from this study may have significant implications for understanding various attention-related disorders. Mangun noted that individuals with conditions such as attention-deficit hyperactivity disorder (ADHD) or autism may experience delays in their ability to narrow their focus.

“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,” he stated.

Co-author Mingzhou Ding, a Distinguished Professor of biomedical engineering at the University of Florida, contributed to the collaborative effort that was supported by the National Institutes of Health and the National Science Foundation.

As research continues to explore the intricacies of the brain’s attention mechanisms, a more comprehensive understanding may pave the way for targeted interventions and improved outcomes for individuals facing attention-related challenges.