Washington, October 31: When the brain fires up the network of neurons that allows us to empathize, it suppresses the network used for analysis, according to a pivotal study led by a Case Western Reserve University researcher.
Again when the analytic network is engaged, our ability to appreciate the human cost of our action is repressed, it revealed.
At rest, our brains cycle between the social and analytical networks. But when presented with a task, healthy adults engage the appropriate neural pathway, the researchers found.
The work suggests that established theories about two competing networks within the brain must be revised. More, it provides insights into the operation of a healthy mind versus those of the mentally ill or developmentally disabled.
“This is the cognitive structure we’ve evolved. Empathetic and analytic thinking are, at least to some extent, mutually exclusive in the brain,” said Anthony Jack, an assistant professor of cognitive science at Case Western Reserve and lead author of the new study.
A number of earlier studies showed that two large scale brain networks are in tension in the brain, one which is known as the default mode network and a second known as the task positive network. But other researchers have suggested that different mechanisms drive this tension:
One theory says that we have one network for engaging in goal directed tasks. This theory posits that our second network allows the mind to wander.
The other theory says that one network is for external attention, and the second network is for internal attention.
The new study showed that adults presented with social or analytical problems – all external stimuli – consistently engaged the appropriate neural pathway to solve the problem, while repressing the other pathway. The see-sawing brain activity was recorded using functional magnetic resonance imaging.
The finding has bearings on a variety of neuropsychiatric disorders, from anxiety, depression and ADHD to schizophrenia – all of which are characterized by social dysfunction of some sort, Jack said.
“Treatment needs to target a balance between these two networks. At present most rehabilitation, and more broadly most educational efforts of any sort, focus on tuning up the analytic network. Yet, we found more cortex dedicated to the social network,” he noted.
Perhaps most clearly, the theory makes sense in regards to developmental disabilities such as autism and Williams syndrome. Autism is often characterized by a strong ability to solve visuospatial problems, such as mentally manipulating two and three-dimensional figures, but poor social skills. People with Williams syndrome are very warm and friendly, but perform poorly on visuospatial tests.
But, even healthy adults can rely too much on one network, Jack said.
Jack worked with former Case Western Reserve undergraduates Abigail Dawson, now a graduate student at the University of Otago in Dunedin, New Zealand; Katelyn Begany, now a graduate student at the University of California, Berkeley; and Kevin P. Barry, now a graduate student at Rensselaer Polytechnic Institute.
Other co-authors are, from Case Western Reserve: former research assistant, Regina L. Leckie and Angela H. Ciccia, an assistant professor of psychological sciences; and Abraham Z. Snyder, MD, a professor of radiology at Washington University in St. Louis.
he research has been published in the current online issue of NeuroImage. (ANI)