New research shows a simple reason why even the most intelligent, complex brains can be taken by a swindler's story – one that upon a second look offers clues it was false.

When the brain fires up the network of neurons that allows us to empathize, it suppresses the network used for analysis, a pivotal study led by a Case Western Reserve University researcher shows.

How could a CEO be so blind to the public relations fiasco his cost-cutting decision has made?

When the analytic network is engaged, our ability to appreciate the human cost of our action is repressed.

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 study shows for the first time that we have a built-in neural constraint on our ability to be both empathetic and analytic at the same time

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," said Anthony Jack, an assistant professor of cognitive science at Case Western Reserve and lead author of the new study. "Empathetic and analytic thinking are, at least to some extent, mutually exclusive in the brain."

The research is published in the current online issue of NeuroImage.

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 shows 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.

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.

Jack said that a philosophical question inspired the study design: "The most persistent question in the philosophy of mind is the problem of consciousness. Why can we describe the workings of a brain, but that doesn't tell us what it's like to be that person?"