Neuroscience advances highlight emotional network in brain

By Brandon Smith

New research suggests that the brain has a physiological switch that toggles between one of two cognitive modes at any given time.

The study, published in the October issue of the science journal NeuroImage, may give crucial insight as to why the brain often fails to be both empathetic

and analytical.

The report answers some questions—while raising many more—about two dominant networks of the brain, known as the default mode network and the task positive network, and their roles in day-to-day life. The study was conducted using functional MRI scans to examine networks of the brain.

Anthony Jack, lead author of the study and an assistant professor of cognitive science at Case Western Reserve University in Cleveland, explained that his research shows that the default mode network may play a larger role in the brain than previously thought.

The default mode network was assumed to be a sort of autopilot resting state or daydreaming state, but Jack’s research indicates that it is actually associated with

human empathy.

“What’s new about this is that the default mode network isn’t really just a resting network,” Jack said. “It’s actually an engaged form of social cognition.”

Jack said the discovery that the default mode network plays a social role associated with empathy may help resolve a disconnect between the mind and the body.

“We tend to think of minds and machines as two different things, which makes it difficult to link the mind with a physical account,”

Jack said.

Marcus Raichle, a professor of neurology at Washington University in St. Louis who is credited with originally co-discovering the default mode network, explained the difference between the task positive and default mode networks. He said each network serves an array of functions in the brain, but the task positive network primarily carries out goal-related tasks.

“The task positive network is a group of brain areas that increase their activity in a goal-directed task,” Raichle said. “When sitting down to read a book or to write something, you’re very focused on that. You are not being self referential, [meaning] you’re not thinking about yourself.”

Previous research had already determined that the default mode network and the task positive network don’t work simultaneously, but instead repress one another depending on the task

being performed.

Jack’s study strengthened the evidence of tension between the two networks. This led him to his second discovery: The default mode network serves as more than just a resting state of mind but is also associated with understanding

human feelings.

Jack’s study showed the anti-correlation between the goal-oriented network and the social network by hooking up 45 individuals to fMRI scanners. Each participant was shown 32 social interactions and asked questions regarding how they perceived the feelings of the people in the problems. In each case, the default mode network became active and repressed the task

positive network.

The individuals were then asked to solve an additional 32 math and physics problems. In each case, the task positive network was active and repressed social cognition.

Jessica Andrews-Hanna, a research associate at the University of Colorado at Boulder who is familiar with the study, explained the significance of recognizing how the default mode network serves

social orientation.

“[Jack’s] paper shows that the default mode network has adaptive functions to help us reflect on our own states and help us predict what will make us happy or sad in

the future,” Andrews-Hanna said.

She explained that the default mode network has far-reaching implications for a great number of emotional conditions because it has now been established as the part of the brain that allows people to reflect on themselves and

their emotions.

Jack said his current and future research may prove useful for treating several behavioral problems and psychiatric disorders. He argued that current treatment for disorders like autism are heavily focused on the task positive network, but it may be more fitting to address the emotional network.

“Social dysfunction is the mark of almost every psychiatric disorder,” he said. “Our culture feels a bit lost at the moment about what we’re supposed to do to improve emotional skills. Giving someone a set of rules is not the same as giving someone the tools to improve their emotional intelligence.”