April Flowers for redOrbit.com – Your Universe Online
Even the most intelligent, complex brains can be taken by a swindler’s story, a new study from Case Western Reserve University shows, even stories that prove false upon a second look.
The new study, published online in the journal NeuroImage, reveals that when the brain fires up the network of neurons that allows a person to empathize, the network used for analysis is suppressed. Our ability to appreciate the human cost of our action is repressed when the analytic network is engaged.
Our brains cycle between the social and analytical networks at rest, when presented with a task, however healthy adults engage the appropriate neural pathway. We have built-in neural constraints on our ability to be both empathetic and analytic at the same time, the study shows.
The findings of this new study suggest that established theories about two competing networks within the brain need to be revised. It also provides insights into how a healthy mind works versus a mentally ill or developmentally disabled brain.
“This is the cognitive structure we’ve evolved,” said Anthony Jack, an assistant professor of cognitive science at Case Western Reserve. “Empathetic and analytic thinking are, at least to some extent, mutually exclusive in the brain.”
Previous studies revealed two large-scale brain networks are in tension in the brain: the default mode network and the task positive network. Other researchers have suggested that different mechanisms drive this tension. For example, one theory says that we have one network for engaging in goal directed tasks, positing that our second network allows the mind to wander.
Jack and his colleagues show that adults presented with social or analytical external stimuli problems consistently engaged the appropriate neural pathway to solve the problem. The other pathway was repressed. They used functional magnetic resonance imaging to record the see-sawing brain activity.
The question which inspired the study was a philosophical query. Jack said, “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?”
“The disconnect between experiential understanding and scientific understanding is known as the explanatory gap,” Jack said. “In 2006, the philosopher Philip Robbins [professor of philosophy at the University of Missouri] and I got together and we came up with a pretty crazy, bold hypothesis: that the explanatory gap is driven by our neural structure. I was genuinely surprised to see how powerfully these findings fit that theory.”
The same neural phenomenon drives the explanatory gap as when we look at a visual illusion such as the duck-rabbit, the study suggests. When you look at the drawing, you can see the duck facing one way or the rabbit facing the other, but not both at once.
“That is called perceptual rivalry, and it occurs because of neural inhibition between the two representations,” Jack said. “What we see in this study is similar, but much more wide-scale. We see neural inhibition between the entire brain network we use to socially, emotionally, and morally engage with others, and the entire network we use for scientific, mathematical and logical reasoning.”
“This shows scientific accounts really do leave something out – the human touch. A major challenge for the science of the mind is how we can better translate between the cold and distant mechanical descriptions that neuroscience produces, and the emotionally engaged intuitive understanding which allows us to relate to one another as people.”
Forty-five healthy college students were recruited, and each was asked to take five 10-minute turns inside a magnetic resonance imager. During these sessions, the researchers presented them with 20 written and 20 video problems that required them to think about how others might feel. They were also presented with an equal number of written and video problems that required physics to solve.
Each video required the students to provide an answer to a yes-no question within 7 seconds. The sessions in the imager included twenty 27-second rest periods, and variable delays of 1,3,or 5 seconds. During each rest period, the students would look at a red cross on the screen in front of them and relax.
The MRI images revealed that social problems deactivated the brain regions associated with analysis and activated the social network, which held true regardless of the media the question was presented in. The physics questions, on the other hand, deactivated the brain regions associated with empathizing and activated the analytical network.
“When subjects are lying in a scanner with nothing to do, which we call the resting state, they naturally cycle between the two networks,” Jack said. “This tells us that it’s the structure of the adult brain that is driving this, that it’s a physiological constraint on cognition.”
The results of this study will have bearing on neuropsychiatric disorders from anxiety and depression to ADHD and schizophrenia, which are all characterized by social dysfunction of some sort.
“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.”
The findings most clearly impact the study of developmental disabilities such as autism and Williams syndrome. People with autism usually have poor social skills, but a strong ability to solve visuospatial problems, such as mentally manipulating two and three-dimensional figures. Williams syndrome sufferers are warm and friendly, but perform very poorly on visuospatial tests.
Jack warns that even healthy people can come to rely too heavily on one network or the other.
“You want the CEO of a company to be highly analytical in order to run a company efficiently, otherwise it will go out of business,” he said. “But, you can lose your moral compass if you get stuck in an analytic way of thinking.”
“You’ll never get by without both networks,” Jack continued. “You don’t want to favor one, but cycle efficiently between them, and employ the right network at the right time.”
Further research is needed to test the theory, and the group is currently investigating whether brains will shift from the social to the analytical when shown people depicted in dehumanizing ways — such as an animal or object. They are also studying how disgust and social stereotyping confound our moral compass by activating the analytical network.