Scientists have discovered that the brain circuits we engage when we think about social matters, such as considering other people’s views, or moral issues, inhibit the circuits that we use when we think about inanimate, analytical things, such as working on a physics problem or making sure the numbers add up when we balance our budget. And they say, the same happens the other way around: the analytic brain network inhibits the social network. Perhaps the study, led by researchers at Case Western Reserve University in Cleveland, Ohio, in the US, and reported early online on 27 October in the journal NeuroImage, explains why some business leaders sometimes overlook the public relations consequences of their cost-cutting exercises. The authors suggest their findings help increase understanding of disorders like autism, ADHD and schizophrenia.

Empathic and Analytic Thinking are Mutually Exclusive The study is believed to be the first to show that humans have a built in neural constraint that stops us thinking empathically and analytically at the same time. Share on Pinterest When not doing anything in particular, our brains switch between social and analytic networks. But, when working on a goal-directed task, healthy adults engage the appropriate neural pathways, say the researchers. Lead author Anthony Jack, an assistant professor of cognitive science at Case Western Reserve, says in a news blog on the university’s website, that “this is the cognitive structure we’ve evolved”: “Empathetic and analytic thinking are, at least to some extent, mutually exclusive in the brain,” says Jack.

Two Networks in Tension Before this study, from previous research, scientists already thought there were two large networks in the brain that were in tension, one called the default mode network and the other called the task positive network. However, there are different views on what drives them. One view proposes that one network is deployed in goal-directed tasks, and when this happens, the other one allows the mind to wander. Another view proposes that one network engages in external attention, while the other is for internal attention. The new study suggests a new explanation: both networks focus on external stimuli, but one is for social problems and the other is for analytical problems, and when the one concerned with one type of problem is engaged, the neural pathways for the other type are repressed.

The Study For their study, Jack and colleagues recruited 45 healthy volunteers, all college students. The participants each spent 10 minutes at a time inside a fMRI brain scanner while a screen in front of them presented them with random selections of 20 written and 20 video problems where they had to think about how other people might feel, and another random selection of 20 written and 20 video problems where they had to use knowledge of physics to solve. After reading a written problem or viewing a video one, each participant then had to give a yes or no answer to a question within 7 seconds. During each session in the scanner, the participants also underwent rest periods lasting 27 seconds, and there were also various timed delays between each test, some lasting 1 second, others lasting 3 or 5 seconds. During the rest breaks the participants were asked to relax and look at a red cross on the screen.

The Results When they examined the results of the fMRI brain scans, the researchers found that when the participants were presented with social problems, the brain regions associated with analytical thinking were deactivated and the regions associated with empathy and social thinking were active. And this was also the same the other way around: when presented with physics questions, the analytic regions were active and the empathy regions were inactivated. These findings were the same for written and video versions of problems. But when the participants were in the resting state, that is not challenged to solve any problems, the activity cycled naturally between the two networks. “This tells us that it’s the structure of the adult brain that is driving this, that it’s a physiological constraint on cognition,” says Jack.

The Explanatory Gap Jack says the study was inspired by one of the eternal philosophical questions surrounding the nature of cosciousness: “Why can we describe the workings of a brain, but that doesn’t tell us what it’s like to be that person?” Something that intrigues scientists interested in this field is what they call the “explanatory gap”, which Jack describes as the “disconnect between experiential understanding and scientific understanding”. He explains how in 2006 he and Philip Robbins, an associate professor of philosophy at the University of Missouri, boldly proposed that the explanatory gap is driven by our neural structure. Looking back on that time after completing this new study, Jack says, “I was genuinely surprised to see how powerfully these findings fit that theory”.

Perceptual Rivalry The results from this latest study appear to suggest that the same brain mechanisms drive the explanatory gap as that which become engaged when we look at a visual illusion known as the “duck-rabbit”, a drawing that can be seen in one of two ways. When you look at it you either see a duck facing one way or a rabbit facing the other way, but you never see both at the same time. Jack says that phenomenon is known as “perceptual rivalry”, which occurs because of neural inhibition between the two representations. “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,” he explains. He suggests this means scientific explanations “really do leave something out – the human touch”. Jack says a major challenge for scientists of the mind is how better to 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”.