The human brain is continuously processing enormous amounts of information. Even something as familiar as driving requires several mental tasks at once. The brain must remember the route, recall how to control the vehicle, and respond to unexpected developments such as a road closure or shifting traffic conditions.
A brain network known as the frontoparietal cortex plays a major role in managing this flow of information. It receives signals from throughout the brain, determines which information is most important, and helps coordinate the appropriate response.
New research from the University of Iowa offers a more detailed look at how this system works when people face uncertainty while making decisions. The findings show how the frontoparietal cortex helps organize information and coordinate responses involving both the brain and the body.
University of Iowa researchers have provided new insight into the brain's information hub, known as the frontoparietal cortex. In this illustration, colored areas identify frontoparietal regions that track uncertainty as participants encounter changes in associations they had previously learned. Image courtesy of Kai Hwang lab, University of Iowa.
How the Brain Changes Its Communication
Using experiments that combined computational modeling with brain imaging, the researchers found that the frontoparietal cortex does not communicate with the rest of the brain in a fixed way. Instead, its connections shift according to the type of information required during different stages of a decision.
The results could help guide future investigations into neurological and psychiatric conditions in which this information exchange may function differently, including attention-deficit/hyperactivity disorder (ADHD) and schizophrenia.
"Our study shows in more detail how the frontoparietal cortex operates -- what kind of information it extracts from other systems and how it uses its connectivity pattern to integrate information that is coming in from different areas of the brain," says Kai Hwang, associate professor in the Department of Psychological and Brain Sciences and the study's corresponding author. "That's the main contribution."
Scientists have long recognized the frontoparietal cortex as an important part of decision making. Its role resembles that of an air traffic controller overseeing a crowded airport. It continually receives information from other brain regions, but it does more than simply collect those signals. Depending on the situation, it filters out some information while giving greater attention to signals that are more relevant.
Building a Big Picture From Incomplete Information
In a study published in 2025, Hwang and his colleagues found that the frontoparietal cortex develops an ongoing high-level summary of information arriving from elsewhere in the brain. It evaluates incoming signals, including information that may be incomplete or uncertain, combines them into a more useful overall representation, and then helps direct other brain regions toward an appropriate response.
"It's like where other areas of the brain don't have all the information, so they send what they have to the frontoparietal cortex for guidance," Hwang explains.
The new research extended those findings by examining how adaptable the frontoparietal cortex is. Specifically, the scientists wanted to understand how its interactions with other brain regions change as the demands of a problem or situation change.
To investigate this, the team recruited 38 participants between ages 18 and 35. Participants learned connections between different combinations of colors, faces, and scenes and particular responses. Those responses included pressing a button using either the index or middle finger on either hand.
The researchers later altered the learned pairings. Participants therefore had to recognize that the associations had changed, learn the new ones, and respond with the correct button using the appropriate hand and finger.
Creating and Tracking Uncertainty
Changing the instructions introduced uncertainty into the task. That allowed the researchers to observe how the frontoparietal cortex changed its connections with other brain systems as participants tried to determine what had happened.
"If they always get it right, they know they've made the correct association, but once they start doing it wrong, they will have to guess, 'Oh, did the context change, or did I not see the color clearly?' That creates uncertainty," Hwang says.
The team combined behavioral data from the experiments with functional MRI scans. Using those results, the researchers developed a computational model that separated signals coming from different areas of the brain and revealed how the frontoparietal cortex brought that information together.
"Rather than simply becoming more active during difficult tasks, we observed how this network dynamically changes how it communicates with other brain regions depending on what information is needed at each stage of a decision," Hwang says.
The results suggest that challenging decisions are not handled simply by increasing activity within this network. Instead, the frontoparietal cortex appears to adjust which brain regions it communicates with according to the information needed at that particular moment.
Possible Links to ADHD and Other Disorders
The findings could eventually contribute to research on psychiatric disorders that make it harder for people to adjust their behavior when circumstances change. Examples can include speaking too loudly in a library or struggling to control impulses, difficulties that can occur with ADHD.
"These are situations where people struggle with regulating their behavior. That, to me, is an integration problem. If that integration function is not working properly, then that could very likely mean they didn't use the right context to regulate their behavior," Hwang says.
Stephanie Leach, a sixth-year graduate student in Hwang's lab, contributed to the design of the project, led the experiments conducted with participants, and co-led preparation of the manuscript.
"Having the opportunity to conduct this research has been especially rewarding because it has allowed me to contribute to answering questions about the most fascinating, mysterious, and complex system we know -- the human brain," says Leach, who is the study's first author.
The study, "Frontoparietal hub connectivity integrates information from multiple sources," was published in the Journal of Neuroscience.
Other contributors include Jiefeng Jiang, who led the computational modeling, and Shannon Stokes. Both are members of the Department of Psychological and Brain Sciences.
Funding for the research came from the National Institute of Mental Health and the Iowa Neuroscience Institute.
