A recently published UC Berkeley study has shed light on the brain’s ability to perform complex cognitive functions through the discovery of “connector hubs” in the brain.
According to the study, led by campus doctoral student Maxwell Bertolero, “connector hubs” allow for effective communication between networks in charge of different tasks such as vision or movement. These hubs are responsible for coordinating the networks required to perform complex actions such as hitting a baseball with a bat.
“We found that each module in the brain appears to be dedicated to a cognitive function,” said Bertolero. “Connectors are more active when these cognitive functions are working at the same time.”
According to Bertolero, over the course of two years, researchers examined the brain activity of 24 different human test subjects. The team examined the subjects across 9,208 experiments involving 77 different tasks and compared brain activity with a map of the brain at rest. Researchers found that brain activity in local nodes did not increase even as activity in connector hubs did.
“Each individual node is not affected,” said Bertolero. “This means everyone does their own thing.”
Researchers concluded that each network in the brain appears to execute a distinct cognitive function autonomous from the other networks, despite the connectivity among them.
The study also found that for more complex tasks engaging multiple networks, brain activity increased only in the connector networks and decreased in local networks. According to the study, this helps keep the burden off individual networks.
“People have hypothesized that this was the case that these hubs were connected to the rest of the brain but there were no real demonstrations or evidence,” said Bertolero. “This was a very strong demonstration of integrative and coordinated functions.”
According to the study, dysfunction in the tissues of local nodes can cause specific impairments while dysfunction in connector nodes, likely due to their roles in integration and coordination across many networks, causes widespread degradation and cognitive deficits. These dysfunctions have been strongly associated with nine brain disorders, including schizophrenia and Alzheimer’s disease.
The cause of Alzheimer’s disease has been poorly understood by scientists, and Bertolero hopes that this study could help provide some insight into these brain disorders.
The next steps for the team include observing exactly how the connector hubs work to examine what happens to the brain when the hubs are significantly damaged, Bertolero said.