Political orientation can be predicted by brain activation differences

Science and Health

Your political views and how you vote can be foretold by what’s going on in your brain. A first-of-its-kind study at Tel Aviv University (TAU) scanned the brains of dozens of politically involved participants while they watched campaign ads and speeches by parties from both ends of the political spectrum, just before one of the last rounds of elections. 

The political sphere has become highly polarized in recent years. Would it be possible to identify the neural mechanisms underpinning such processes? In fact, recent political polarization has illustrated how individuals with opposing political views often experience ongoing events in markedly different ways. 

The study participants, half of them right-wing and half left-wing, were scanned using functional magnetic resonance imaging (fMRI), a method that measures brain activation. Surprisingly, it was found that political-dependent differences in the brain response emerged already in brain regions that are involved in vision and hearing, and, in fact, the response in these regions was enough to predict an individual’s political views.

The researchers note that right-wing participants had synchronized brain responses (meaning their brains worked in a similar manner) while they watched the right-wing stimuli, whereas left-wing participants’ brains worked in a similar manner while they watched the left-wing stimuli. This was true for regions within the sensory, motor, and somatosensory cortices that are responsible for vision, hearing and movement.

The study was led by Noa Katabi, a research student in the lab of Dr. Yaara Yeshurun in TAU’s School of Psychological Sciences and the Sagol School of Neuroscience. The study was published in the Journal of Neuroscience under the title “Deeper Than You Think: Partisanship-Dependent Brain Responses in Early Sensory and Motor Brain Regions.”

Dr. Yaara Yeshurun. (credit: TEL AVIV UNIVERSITY)

Widespread partisanship

During the study, participants watched video clips including a neutral (in terms of political characteristics) video segment and different political campaign ads and political speeches by politicians from both right-wing and left-wing blocs. The researchers were surprised to discover widespread partisanship-dependent brain activation and synchronization when right-wing individuals watched the videos of their political bloc, or when left-wing persons watched the videos of left-wing politicians.

Interestingly, researchers found that such partisanship-dependent differences in brain synchronization were not limited to “higher” areas of the brain that are associated with interpretation and abstract thinking, as was previously believed. Rather, these differences occurred already in regions responsible for sight, hearing and even touch. Importantly, no such differences were found with respect to neutral content. Therefore, these results uncover more fundamental neural mechanisms underlying processes of political polarization, the researchers noted. 

“The research clearly showed that the more the subjects were politically aligned with a certain group, the more their brain response was synchronized, including in motor and somatosensory areas, that is, those areas of the brain that are active when we move or feel things with our senses,” said Yeshurun. “In fact, just by the brain’s response in these primary sensory areas, we could tell if a certain individual was left- or right-wing.”

Intriguingly, to predict participants’ views, it was not necessary to examine the activity in “higher” brain areas that are involved in understanding why a certain character did something, or what that character thinks and feels, she wrote. “It could be done just by examining an area of the brain that is responsible for seeing or hearing.”

The researchers think that this surprising finding is due to the fact that the participants they chose were politically involved and to the timing of the experiment – a few weeks before the elections, when the political atmosphere in Israel was very present and emotional.

“This is the first study to show political-dependent brain activity in early sensory and motor areas, and it can be said that at the most basic brain level, rightists and leftists in Israel literally (and not just metaphorically) don’t see and hear the same things,” said Yeshurun. “I think that if we try to understand how people who hold opposite political views to ours experience the world, we might be able to conduct a slightly more effective public discussion that can hopefully attenuate the current political polarization.”