Our brains need to constantly filter out distractions to stay focused, but how they do this in complex environments has not been fully understood. Researchers have found that instead of simply focusing on important information, the brain actively suppresses irrelevant information, challenging classic theories of cognitive control.
Staying focused in a world full of distractions is a major challenge for the human brain. To achieve a goal, we need to constantly manage multiple sources of information, some relevant and others that can distract us.
However, most studies on cognitive control have so far looked at simple scenarios, with just one main task and a single distraction. This has left a gap in understanding how the brain deals with more complex environments, where there are multiple distractions at once.
To reach these conclusions, researchers from Washington University in St. Louis, USA, designed a series of three experiments in which participants had to perform cognitive tasks while being exposed to distractions from different dimensions, such as visual, auditory or symbolic stimuli, while their brains were scanned.
The tests were designed to measure how participants adjusted their focus after facing previous conflicts. In addition, the scientists used a computational model based on neural networks to simulate the cognitive processes involved, allowing them to test different hypotheses about how the brain deals with multiple distractions.
One of the main innovations of this study is that, unlike previous research, it analyzed how the brain deals with multiple distractions at the same time. Traditionally, scientists study focused attention using only one relevant piece of information and one distraction, as in the famous Stroop Task.
In the Stroop Task, participants are shown words that represent colors (such as “red,” “blue,” or “green”), but these words may be written in a different color than the one they describe. For example, the word “blue” may be written in the color red. The challenge is to ignore the meaning of the word and say only the color of the ink.
When there is a conflict between the word and the color, people take longer to respond correctly because the brain has to inhibit the distraction caused by reading the word automatically. Previous research has used this type of test to understand how the brain manages distractions and has developed simple computational models of neural networks to simulate this process.
However, this new study went further, looking at how the brain responds when it has to ignore multiple distractions at once, bringing the research closer to everyday reality.
After conducting three experiments, the results strongly showed that the brain adopts the second strategy: it prioritizes the suppression of distracting information rather than simply increasing focus on useful information.
In addition, the researchers found that this brain adaptation is highly specific. That is, if a distraction occurs in a certain category of information, the brain learns to deal better with future distractions from that same category, but does not generalize this ability to other types of distractions.
In other words, if you get used to ignoring noise while studying, that does not mean you will be equally good at ignoring notifications on your phone.
To better understand this mechanism, scientists developed a computational model based on neural networks. This model was only able to reproduce the real results when it included multiple independent units that detect and deal with conflicts separately.
This suggests that, rather than a single general cognitive control system, the brain may have different specialized mechanisms to suppress distractions from different sources.
These findings challenge classical theories of cognitive control and show that our brain has a more sophisticated and segmented way of dealing with distractions than previously thought.
This knowledge could have important applications, from developing techniques to improve concentration, cognitive training, treating ADHD, and even improving artificial intelligence models that simulate the functioning of the human brain.
READ MORE:
Distractor-specific control adaptation in multidimensional environments
Davide Gheza & Wouter Kool
Nature Human Behaviour (2025)
Abstract:
Goal-directed behaviour requires humans to constantly manage and switch between multiple, independent and conflicting sources of information. Conventional cognitive control tasks, however, only feature one task and one source of distraction. Therefore, it is unclear how control is allocated in multidimensional environments. To address this question, we developed a multidimensional task-set interference paradigm, in which people need to manage distraction from three independent dimensions. We use this task to test whether people adapt to previous conflict by enhancing task-relevant information or suppressing task-irrelevant information. Three experiments provided strong evidence for the latter hypothesis. Moreover, control adaptation was highly dimension specific. Conflict from a given dimension only affected processing of that same dimension on subsequent trials, with no evidence for generalization. A new neural network model shows that our results can only be simulated when including multiple independent conflict-detector units. Our results call for an update to classic models of cognitive control and their neurocomputational underpinnings.
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