While this approach has yielded major advances, it has left unresolved one of the most basic facts about human cognition: its overall unity as an integrated system.

Now, researchers at the University of Notre Dame have conducted a neuroimaging study to investigate how the brain is organized and how that integrated system gives rise to intelligence.

“Neuroscience has been very successful at explaining what particular networks do, but much less successful at explaining how a single, coherent mind emerges from their interaction,” said , the Andrew J. McKenna Family Professor of Psychology in Notre Dame’s .

How cognitive ties form ‘general intelligence’

Psychologists have long known that areas as diverse as attention, perception, memory and language are correlated, forming what they term “general intelligence.” This accounts for how humans function and adapt in a wide range of academic, professional, social and health contexts. It shapes how efficiently we learn, reason and perform in response to a multitude of everyday problems and tasks.

For more than a century, this structure has suggested that cognition is unified at a fundamental level. What has been missing is a theory to explain why such unity exists.

“The problem of intelligence is not one of functional localization,” said Barbey, who is also the director of the and the . “Contemporary research often asks where general intelligence originates in the brain — focusing primarily on a specific network of regions within the frontal and parietal cortex. But the more fundamental question is how intelligence emerges from the principles that govern global brain function — how distributed networks communicate and collectively process information.”

Barbey and his research team, including Notre Dame graduate student and lead author , investigated the predictions of the unifying framework, called the Network Neuroscience Theory. was recently published in the journal Nature Communications.

The Network Neuroscience Theory

General intelligence is not itself a skill or strategy, the researchers argued. It is a pattern — the tendency for diverse abilities to be positively correlated. The study argues that this pattern reflects differences in how efficiently brain networks are organized and work together.

To test this claim, the cognitive neuroscientists analyzed brain imaging and cognitive data from one of the largest studies conducted to date, examining 831 adults in the , along with an independent sample of 145 adults in the INSIGHT Study, which was funded by the . The researchers integrated measures of both brain structure and function to enable a more precise characterization of the human brain.

Rather than identifying intelligence with a particular cognitive function or brain network, the Network Neuroscience Theory characterizes it as a property of how the brain works as a whole. In this view, intelligence reflects how brain networks are coordinated and dynamically reconfigured to solve the diverse problems we encounter in life.

This research represents an important shift, according to Barbey and Wilcox.

“We found evidence for system-wide coordination in the brain that is both robust and adaptable,” Wilcox said. “This coordination does not carry out cognition itself, but determines the range of cognitive operations the system can support.”

“Within this framework, the brain is modeled as a network whose behavior is constrained by global properties such as efficiency, flexibility and integration,” Wilcox said. “These properties are not tied to individual tasks or brain networks, but are characteristics of the system as a whole, shaping every cognitive operation without being reducible to any one of them.”

“Once the question shifts from where intelligence is to how the system is organized,” Wilcox noted, “the empirical targets change.”

Intelligence as a globally coordinated system of networks

The researchers found evidence to support four predictions of the Network Neuroscience Theory.

First, the theory predicts that intelligence is not localized to a single brain network but arises from processing distributed across multiple networks. Intelligence, therefore, depends on how the brain manages the division of labor across different networks and combines them as needed.

Second, for the brain to manage this distributed processing, it requires integration and effective long-range communications. To synchronize those efforts, Barbey said, there is “a large and complex system of connections that serve as ‘shortcuts’ linking distant brain regions and integrating information across the networks.” These pathways connect structurally distant areas of the brain, enabling efficient communication and supporting coordinated processing across the system.

Third, effective integration requires regulatory control that coordinates interactions among networks by shaping how information flows throughout the brain. These areas serve as regulatory hubs, reaching out to other networks to orchestrate the brain’s ongoing activities. They selectively recruit the appropriate networks for the specific task at hand — whether it be piecing together subtle clues to make sense of a problem, learning a new skill or deciding whether a situation requires careful deliberation or a rapid, intuitive response.

Finally, Barbey said that general intelligence depends on the brain’s ability to balance local specialization with global integration. In other words, the brain functions best when tightly connected local clusters communicate well, but are still able to link to distant regions of the brain across short communication paths. This makes the most effective problem-solving possible, according to the co-authors.

The research suggests that intelligence is unified not because the brain relies on a single general-purpose processor, but because the same organizational principles shape how all cognitive functions work together.

Across both datasets, individual differences in general intelligence were consistently associated with these system-level properties. No single region or canonical “intelligence network” accounted for the effect.

“General intelligence becomes visible when cognition is coordinated,” Barbey noted, “when many processes must work together under system-level constraints.”

Applications for artificial intelligence

The implications of this study extend beyond intelligence research, he added. By grounding cognition in large-scale organization, the study offers a principled account of why the mind is unified at all.

This framework helps explain why intelligence develops broadly during childhood, declines with aging and is particularly sensitive to diffuse brain injury. In each case, it is large-scale coordination — not isolated function — that changes.

The findings also inform ongoing debates about artificial intelligence and how AI models are developed. If general intelligence in humans arises from system-level organization rather than from a dedicated general-purpose mechanism, then achieving general intelligence in artificial systems may require more than the accumulation or scaling of specialized capabilities.

“This research can push us into thinking about how to use design characteristics of the human brain to motivate advances in human-centered, biologically inspired artificial intelligence,” Barbey said.

“Many AI systems can perform specific tasks very well, but they still struggle to apply what they know across different situations.” Barbey said. “Human intelligence is defined by this flexibility — and it reflects the unique organization of the human brain.”

The research was conducted with co-authors Babak Hemmatian and Lav Varshney of Stony Brook University.

Contact: Tracy DeStazio, associate director of media relations, 574-631-9958 or tdestazi@nd.edu

The war in Ukraine is not just a war against a people, but a war on culture.

And after nearly two years of fighting, it is destroying Ukraine’s cultural heritage on a scale not seen since World War II, according to new research by University of Notre Dame faculty members and .

Kuijt, a professor in the , and Donaruma, a professor of the practice in the , visited Ukraine to see firsthand and begin to document the extent of the damage to cultural sites including churches, schools, opera houses, libraries and archaeological sites.

Working in collaboration with researchers from the Taras Shevchenko National University of Kyiv, the Institute of Archaeology at the National Academy of Sciences of Ukraine and the University of Wyoming, the team completed the first ground-based survey of the region since the invasion. Their findings were .

“The intent by the Russians is essentially obliterating Ukrainian culture, heritage and history,” Kuijt said. “They have been targeting cultural features of society that have no military capability, no hardened infrastructures that would be used in defense. And there are many researchers who have started doing work with satellite and aerial photos, but at some point, you have to go into the field to truly get a sense of the damage.”

Kuijt and Donaruma visited liberated areas in Ukraine to assess, film and document the destruction. Their interdisciplinary collaboration allowed Kuijt, an archaeologist, and Donaruma, a narrative and documentary filmmaker, to provide a more holistic view of the conditions in Ukraine’s built environment.

Walking through the ruins, Kuijt said, revealed more widespread and far more extensive damage than the team anticipated. They also found that the devastation not only exists above ground from missile strikes, but also extends below the surface due to the widespread trench systems used by military forces.

The researchers mapped out the substantial damage incurred by churches and historic buildings from as early as the 11th and 12th centuries. Architectural monuments and UNESCO-listed heritage sites — even those that have appeared fairly intact in satellite imagery — have also suffered.

“Beyond the destruction and damage, particularly in populated, civilian areas, we were astonished to see the amount of preparation and defense of cultural heritage sites and objects,” Donaruma said. “Large sheets of metal covered stained-glass windows. Fortified cages covered statues, and museums were boxing artifacts for storage.”

For every church the researchers found in similar condition, Kuijt estimated there are three to four other archaeological sites below ground that are also impacted.

Despite modern military advancements such as satellites, drones and tanks, much of the war in Ukraine is reliant on trenches and bunkers — which has resulted in digging and tunneling through the ground, often underneath or right up to the foundations of crucial heritage sites. This has likely destroyed thousands of archaeological spaces, according to Kuijt, including medieval cemeteries and Bronze Age settlements.

This first hit home for Kuijt and Donaruma when visiting a previously unknown graveyard near St. George Chapel in Oster. There, team members discovered that the trench system had exposed the foundations of the 11th-century church and portions of the cemetery associated with it.

Further explorations revealed that other burial mounds and cemetery sites in the region have been affected by both missile strikes and underground trench systems, including one of the largest 11th-century necropolises in Ukraine.

The region has played a key role throughout human history, Kuijt said, as a crossroads of ancient people, culture, religion, language and literature for thousands of years.

“Some of our best understanding of Paleolithic and Neolithic times was formed around the Black Sea,” he said. “This is where Bronze Age villagers created structures and villages that traded pottery with people from Turkey, Georgia and other places. Vikings moved through and traded in these areas. The emergence of specific forms of Christianity occurred here, along with the construction of its churches — including ritual and religious life that is unique in this area. So, in many ways, this should be viewed as a global heritage.”

Because the war in Ukraine is ongoing, the researchers know that further destruction is likely, especially in the eastern and southern areas of the country where the most intense battles are currently happening. However, it is critical to begin assessing the damage now, even as it continues to occur, the researchers said.

“There is very much a ticking clock,” Kuijt said. “This is essentially cultural triage. We need to assess which antiquities are the most important and the least damaged, and how we can allocate resources to try to protect those as best we can.”

While they anticipate that it may be five to 10 years before archaeologists will be able to truly sort out how much damage has taken place, Kuijt and Donaruma are hopeful their work will help to begin documenting all that the Ukrainian people have lost — and to prevent or minimize the ongoing devastation.

“Ian and I are both longing to return to Ukraine to continue  to keep the world apprised of the war and impact it has on lives and cultural heritage,” Donaruma said. “We have made so many friends in Ukraine in a short period of time that our passion to help and continue this work is of the utmost importance.”

Contact: Tracy DeStazio, associate director of media relations, 574-631-9958, tdestazi@nd.edu

Contact: Carrie Gates, associate director of media relations, 574-631-4313, c.gates@nd.edu

In a world increasingly dependent on social media, consumers rely on reviews and ratings for everything from restaurants to service providers. And those opinions, published instantly online, can make or break a business.

University of Notre Dame economist A. Nilesh Fernando recently examined whether a rating system could impact a far greater issue — the effort to prevent the widespread abuse of South Asian migrants in the Persian Gulf region at the hands of their employers.

A study by Fernando, an assistant professor in the Department of Economics, and Niharika Singh, a postdoctoral research scholar at Columbia University, focused on a Sri Lankan governmental review system enacted to combat labor abuses of that country’s migrant workers employed in Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates. 

“As with many international migrants, Sri Lankans leave home to find employment as laborers in construction and as domestic workers and vehicle and machinery operators, hoping to financially support their families and build better lives,” Fernando said. “In fact, roughly 17 percent of the total Sri Lankan work force — approximately 1.5 million workers — were employed in the Gulf region alone in 2015.” 

Unfortunately, many Gulf region employers routinely withhold pay; seize passports; engage in verbal, physical and sexual abuse; and fail to honor their contracts, leaving migrant workers with few options for legal recourse, Fernando said. Using administrative data on more than 1.5 million Sri Lankan migrant workers, the researchers found that approximately 8 percent of them make a complaint to a consulate to report labor abuses — with 80 percent of those complaints coming from female migrant workers — although the occurrence of abuse is likely much higher. 

Countries that supply migrant workers have no power to control labor laws in host countries, and banning migration altogether hurts both the migrants and the economies of their home countries. However, migration in the Gulf corridor is often mediated by recruitment agencies, Fernando noted, and targeting these intermediary agencies for reform has the potential to help solve the problem.

“Vulnerable migrants place their trust in intermediaries in return for finding them safe passage and employment opportunities,” he said. “As a consequence, these middlemen have enormous power in determining the potential quality of the migrant’s job.

“But if nobody holds an intermediary accountable in Sri Lanka, and an abusive employer is willing to pay you more money, they may as well send the migrant to an abusive employer. We found that some agencies systematically send migrants to abusive employers; we call them ‘underperforming’ or ‘low-quality’ agencies. Those are the ones that you really want to find a way to improve on their practices.” 

In 2010, the Sri Lankan Bureau of Foreign Employment instituted a rating program to give star ratings to eligible intermediaries to incentivize them toward better placement practices. (“Eligible” intermediaries were those agencies that sent more than 100 migrants to jobs in 2009.) The government announced it would grant intermediaries zero to five stars based on each agency’s total recruitment, skill intensity of jobs matched and performance in resolving complaints. In 2012, the star ratings were then announced in a public ceremony and made available in an online database. 

To assess this “regulation by reputation” strategy, Fernando and Singh examined how eligible Sri Lankan intermediaries responded, beginning with when they first learned they would be reviewed and rated based on their business practices. They discovered that the star-rating policy did make a difference and that intermediaries responded proactively to an incentive that threatened their reputation — especially those agencies that were underperforming. 

To determine this, Fernando and Singh compared agencies that were eligible to those that were not, by tracking individual migrants and their contracts, local recruiters, foreign employers and, ultimately, whether they sought assistance from a Sri Lankan consulate for an employment-related dispute.

“I can’t think of something more consistent with Notre Dame’s mission than caring about the dignity of labor. Any human being, no matter where they come from — no matter if they are rich or poor, Black, brown or white — has an inherent dignity about them that we should respect.”

What was most surprising, Fernando said, was the timing and the efficacy of the policy.

“The period between 2010 and 2012 when the intermediaries were given the chance to get their act together was the most productive,” Fernando said. “That was when the agencies, particularly those who were previously underperforming, started complying and taking action to improve what their future rating would be — before it was revealed how many stars they had garnered.

“If you create a reputational incentive for these intermediaries — if you give them a carrot, so to speak — then they start caring about where they place migrants. The agencies will choose better employers when they have reason to do so.” 

In a related result, Fernando and Singh found that employers also sought out the higher-rated intermediaries to find workers for them because they deemed them more dependable and trustworthy in finding reliable, consistent help.

The researchers did not find evidence, however, that migrants responded to the star ratings, in large part because the ratings were primarily made available on the internet, which, at the time, was accessible to less than 12 percent of the Sri Lankan population. In fact, only 14 percent of the migrants had ever heard of the rating program. The researchers concluded that work still needs to be done to better market the star ratings to a broader audience.

Improving the lives of Sri Lankan migrant workers is not only personally important to Fernando, who is from Sri Lanka, but is also completely aligned with the spirit of Notre Dame, he said.

“I can’t think of something more consistent with Notre Dame’s mission than caring about the dignity of labor. Any human being, no matter where they come from — no matter if they are rich or poor, Black, brown or white — has an inherent dignity about them that we should respect.”

“And being able to conduct research that uses credible methods, that is empirically oriented, that uses a ton of data to make simple points, is very much consistent with the idea of valuing human development and human flourishing.”