Neuromodulation a Cure for Prejudice?

Liam Davenport

October 23, 2015

Prejudicial and religious beliefs can be reduced by direct magnetic stimulation of the brain, scientists have discovered in findings that suggest that a fear response to threat may encourage negative or ideologic feelings.

They found that transcranial magnetic stimulation (TMS) of the posterior medial frontal cortex (pMFC), which is linked to responses to threats, resulted in significant reductions both in negative feelings toward immigrants who are critical of their country and in religious beliefs.

"The results provide evidence that relatively abstract personal and social attitudes are susceptible to targeted neuromodulation, opening the way for researchers to not only describe the biological mechanisms undergirding high-level attitudes and beliefs, but also to establish causality via experimental intervention," the investigators write.

"Understanding the psychological and biological determinants of increases in ideological commitment may ultimately help us to identify the situational triggers of, and individuals most susceptible to, this phenomenon, and thereby gain some leverage over the zealous acts that follow," they add.

The research, which is a collaboration between the University of California, Los Angeles, and the University of York, the United Kingdom, was published online September 4 in Social Cognitive and Affective Neuroscience.

"Striking" Finding

Previous research has suggested that the pMFC plays a key role in identifying differences between desired and current conditions and in subsequently adjusting behavior during decision-making tasks. This involves, in humans, increases in moral or cultural values following exposure to threats.

To examine the role of the pMFC in adherence to group and religious ideology, 38 undergraduates with largely moderate or extremely conservative views were paid to take part in a series of apparently unrelated tasks and to undergo TMS or sham stimulation.

Initially, the participants underwent TMS or sham stimulation and then engaged in a 10-minute filler task to ensure that the TMS downregulated pMFC activity. The participants were primed to have thoughts of death via a brief writing task, and they underwent a self-reported assessment of the impact of TMS on conscious emotion.

The participants next read essays, one critical and one complimentary of the United States, ostensibly written by immigrants, and were asked to evaluate the authors' personalities and attitudes. Finally, religious belief was measured using two self-report scales focusing on "negative" beliefs in the devil, demons, and hell and "positive" beliefs in god, angels, and heaven.

TMS had no overall impact on self-reported emotion. However, participants who had undergone TMS rated the immigrant critical of the United States 28.5% more positively than those who underwent sham stimulation (P = .012).

There was, however, only a nonsignificant 8.2% increase in the rating of the pro-US immigrant in the TMS group compared with the group receiving sham stimulation.

There was also a marginal trend for reduction in overall religious belief following TMS vs sham stimulation (P = .061). This was driven by a significant 32.8% reduced conviction in positive religious beliefs following TMS vs sham stimulation (P = .035). The difference in negative religious beliefs following TMS and sham stimulation was not significant.

Discussing the findings, lead researcher Colin Holbrook, PhD, Department of Anthropology, Center for Behavior, Evolution and Culture, University of California, Los Angeles, suggested that although this is outside the scope of the study, the example of the immigrant essay on the United States was illuminating in terms of some of the current issues facing society.

"What people often do in the face of criticisms, even when the criticisms are well founded, is, rather than opening themselves to the possibility that maybe they should try to meet these critics or these people from other groups and try to reconcile or come to some accommodation, they sort of circle the wagons and double down in a kind of hardening of their beliefs," he said.

He explained that from an ideologic point of view, if one's group ideology and its merits are being challenged, one solution is to "shout down the critic" and devalue the criticisms. "And that's an evil we found."

"The participants in our study who had not got this brain region temporarily deactivated rated the hostile critics quite a bit lower, which suggests that they were sort of solving the problem of the criticisms this person was posing by derogating them, by responding to them in a hostile way, and it's hard not to see parallels in the news," he said.

"By deactivating this region that would normally recruit this kind of a hostile response, we found that the participants were not only more welcoming, they weren't just more positive in their response towards this critical immigrant as a person, but they also rated the person as more reasonable, which I think is quite striking," he added.

One way in which these findings could perhaps illuminate ways to tackle prejudice and hostile responses is, Dr Holbrook believes, to provide accurate information.

Citing the rumors and false information about immigrants to the United States that are frequently circulated in emails by "some harder right wing groups," Dr Holbrook said, "We've shown that perceptions of threat exacerbate prejudice. One really simple thing that's hard to imagine a downside to would be to really put a focus on raising people's awareness of the truth.

"In many cases, the truth is that this group is not so threatening, and if people can begin the conversation without feeling threatened, they're...much more willing to listen.

"I don't mean to sound Pollyannaish. There are other situations in which there are certain groups that are genuinely very frightening as well, like certain militant groups, and so on, but I think in many cases of social injustice or misunderstanding, underneath the surface part of prejudicial reactions is just a fear.

"We don't do this research in order to solve social problems, we do it as pure science, but one always hopes that finding out more about how the mind operates may have useful implications in terms of how to deal with problems in the real world," he added.

"Thorny" Issues

Approached for comment, Ronald W. Pies, MD, professor of psychiatry and lecturer on bioethics, State University of New York Upstate Medical University, in Syracuse, and clinical professor of psychiatry, Tufts University School of Medicine, Boston, Massachusetts, said that the study addresses "an area of scientific, cultural, and political importance."

"While these findings are intriguing, the limitations of the study must be acknowledged," he told Medscape Medical News.

"This small study population of paid, undergraduate volunteers may not be representative of, for example, political or religious 'extremists' (however that term may be defined) as we usually encounter them.

"We can't conclude, for example, that acts of 'horrific injustice' or other 'zealous acts' (the authors' terms) are mediated by the pMFC or any particular brain region; thus, the practical import of these findings, in terms of what the authors call 'leverage' over extremist acts, is far from clear."

He noted that although the impact of long-term religious and cultural acculturation and indoctrination on pMFC activity is not explored, "the authors have helped lay the foundations for future studies in that area."

Dr Pies noted that the researchers have raised some "thorny" issues. For example: "Would it be ethical to use TMS to modulate the extreme beliefs of someone identified by the government as a 'terrorist' if that person did not consent to such neuromodulation? Could that sort of 'leverage' ever be exploited by governments in a coercive way?

"These questions, of course, are well beyond the scope of the present study but may well arise as potential uses of 'neuromodulation' are pondered by governmental and nongovernmental agents."

The study has also prompted concerns among some online and media commentators that the technology could be used to coercively influence a person's beliefs.

"It's worth mentioning that this technique requires a very loud, very expensive, fairly large machine operated by a technician who's an expert, and there's no way that I can conceive of that this kind of magnetic energy could be directed into anyone's brain without their knowledge. Even if it were, the effects we showed were meaningful, but they weren't absolute," he said.

"We didn't turn people into atheists, which a bunch of coverage has been saying. That's just not accurate.... The effect only lasts an hour, and so people can relax. Instead, I would say that because it's a magnet, for some reason people feel that there's something more sinister.

"They should appreciate that the things they allow into their eyes and ears through the television set or through the websites they are looking at are also changing the electrical patterns in their brain and also influencing their beliefs. So the real concern is what they're watching on TV," he concluded.

The authors and Dr Holbrook have disclosed no relevant financial relationships.

Soc Cogn Affect Neurosci. Published online September 4, 2015. Abstract


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