A new UCLA imaging study finds political party allegiance affects the brain activity of partisans viewing the faces of candidates.
Published online July 9, 2006, by the peer-reviewed journal Neuropsychologia, the study finds a partisan's brain responds to the opposition candidate's face by activating cognitive networks designed to regulate emotion.
Researchers at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA suggest the neural activity has one of three goals: 1) suppression of unpleasant emotions; 2) suppression of latent positive feelings toward an opposing candidate; or 3) an increase in negative feelings toward an opposing candidate.
"We still have much to learn about the neural basis of political decision making; however, these findings show party allegiance has a clear impact on brain activity," said lead author Marco Iacoboni, associate professor in residence at the Semel Institute, the David Geffen School of Medicine at UCLA and the UCLA Brain Research Institute.
"Most importantly, our findings show how political attitudes can guide the activation of emotional systems in the brain and influence how people regulate those emotional responses," Iacoboni said. "Politics is a ubiquitous form of human social interaction and may very well be an effective way of learning more about the neural basis of social behavior."
Using powerful fMRI equipment at the Semel Institute's Ahmanson-Lovelace Brain Mapping Center, the research team scanned the brains of 10 registered Democrats and 10 registered Republicans as the subjects viewed the faces of 2004 presidential contenders George Bush, John Kerry and Ralph Nader. The study was conducted in the heat of the campaign that year.
Viewing an opposition candidate produced signal changes in cognitive control circuitry in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulated cortex (ACC), as well as in emotional regions in the insula and anterior temporal poles. The ACC is important to attention control and self-monitoring, and together with the DLPFC forms a network that monitors response conflict and, when necessary, regulates emotion.
The level of network activity in study participants correlated with self-reported ratings about how the subject felt emotionally about the candidates. The more negative the feelings about the opponent and more positive the feelings about the favorite candidate, the greater the brain activity discriminated between the two faces.
The effect was strongest for ratings of George Bush, which tended to differ more between Democrats and Republicans than did ratings of John Kerry. In addition, Republicans showed widespread signal changes looking at Nader, compared with Bush. Those changes were not seen in Democrats as they viewed Nader.
The research was supported in part by FKF Applied Research LLC. Other support was provided by the Brain Mapping Medical Research Organization, Brain Mapping Support Foundation, Pierson-Lovelace Foundation, The Ahmanson Foundation, Tamkin Foundation, Jennifer Jones-Simon Foundation, Capital Group Companies Charitable Foundation, Robson Family, William M. and Linda R. Dietel Philanthropic Fund at the Northern Piedmont Community Foundation, Northstar Fund, and National Center for Research Resources grants.
Co-investigators with Iacoboni were Jonas T. Kaplan and Joshua Freeman of the Semel Institute for Neuroscience and Human Behavior at UCLA and the David Geffen School of Medicine at UCLA.
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