Researchers discover effects of exposure to negative stereotypes on brain – sciencedaily



The recent murders of unarmed individuals such as George Floyd, Breonna Taylor, Ahmaud Arbery, and Tony McDade have sparked a national conversation about the treatment of black people – and other minorities – in the United States.

“What we are seeing today is a close examination of the hardships and indignities that people have faced for a very long time because of their race and ethnicity,” said Kyle Ratner, assistant professor of psychological and brain sciences at UC Santa Barbara. As a social psychologist, he is interested in how social and biological processes generate intergroup biases and feelings of stigma.

According to Ratner, “It is clear that people who belong to historically marginalized groups in the United States face serious stressors in addition to the daily stressors experienced by members of non-disadvantaged groups. For example, there is the trauma of overt racism, stigmatizing portrayals in the media and popular culture, and systemic discrimination that leads to disadvantage in many areas of life, from employment and education to care. health and housing to the legal system. “

Concerned about the negative rhetoric directed at Latinx individuals, Ratner and his lab investigated how exposure to negative stereotypes experienced by Mexican-American students can influence the way their brains process information.

In a recent article published in the journal Social, cognitive and affective neurosciences, the research team is focusing on how exposure to negative stereotypes affects responses to monetary incentives. Their conclusion: The brains of Mexican-American college students exposed to negative stereotypes anticipate rewards and punishment differently than those who weren’t so exposed. The discovery, he said, is the first step in a series of studies that could help researchers understand the neural pathways through which stigma can have adverse effects on psychological and physical health.

‘I’m so tired of this’

Much existing research has focused on how stigma and discrimination trigger anger, racing thoughts, and high arousal. Although Ratner thinks this is a reaction people experience in certain contexts, his recent work focuses on the psychological fatigue of hearing your group denigrated. “It’s that feeling of ‘oh, not yet’ or ‘I’m so sick of this’,” he said, describing some reactions to the stress of managing self-definition in the face of negative stereotypes.

While noting several years ago that stigma can produce this feeling of withdrawal and resignation, Ratner recalled the work he did earlier in his career regarding the link between stress and depressive symptoms.

“In work I was involved with over a decade ago, we have shown that the stress of life can be associated with anhedonia, which is a blunt sensitivity to positive and rewarding information, such as gaining success. ‘money,’ he said. “If you’re not sensitive to the rewarding things in life, you basically remain sensitive to all the frustrating things in life, without that positive buffer. And that’s a path to depression.”

Since stigma can be conceptualized as a social stressor, Ratner wanted to determine whether exposure to negative stereotypes could also be linked to reward sensitivity.

Reward processing in the brain

Ratner and colleagues focused on the nucleus accumbens, a subcortical brain region that plays a central role in anticipating pleasure – the “desiring” stage of reward processing that motivates behaviors.

Using functional MRI to measure brain activity, the researchers asked Mexican-American students at UCSB to view series of video clips in quick succession, then gave these students the opportunity to earn money. ‘money or to avoid losing money.

In the control group, viewers saw news and documentary clips on social issues in the United States that were relevant to the country in general: childhood obesity, teenage pregnancy, gang violence, and low numbers of high school graduates. .

In the stigmatized group, subjects were shown news and documentary clips covering the same four areas, but which distinguished the Latinx community as the group specifically at risk for these issues.

“These videos were not overtly racist,” Ratner said of the stigmatizing clips. On the contrary, he explained, the videos tended to devote disproportionate attention to the association between specific social problems and their effects in the Latinx community, rather than presenting them as problems of American society in his. together. The clips came mainly from mainstream news agencies – the presenters and narrators, he said, seemed to “present the facts as they understood them,” but the content of these clips reinforced negative stereotypes.

After repeated exposure to negative stereotypes, research participants were asked to complete a Monetary Incentive Timeframe (MID) task, which required them to press a button every time they saw a star in the screen. Pressing the button fast enough either made money or wasted money.

In individuals who saw the stigmatizing clips, the nucleus accumbens reacted differently to waiting for the star to appear, compared to those who saw the control clips, a pattern which suggests that exposure to Negative stereotypes “spilled over” to affect how participants were to anticipate winning and losing money.

“We saw that something about watching these stigmatizing videos later influenced the pattern of response in that region of the brain,” Ratner said. This suggests that the nucleus accumbens represents the potential for making and losing money differently in the brains of those who have seen the stigmatizing videos before than those who have not, he explained. The researchers also found that the group who saw the stigmatizing videos reported lower arousal levels just before starting the MID task, which corresponds to experiences of stigma with a demotivating effect.

“The nucleus accumbens is very important for motivated behavior, and the motivational sparks are important for many aspects of daily life,” said Ratner. A loss of motivation, he continued, is often experienced by those who perceive their situation as out of their control.

One of the reasons that negative stereotypes in media and popular culture are so problematic is that they make people feel stigmatized even when they are not personally targeted in their daily lives by fanatic people, a he explained. “It becomes something you cannot escape – similar to other stressors that are beyond people’s control and cause anhedonia.”

Ratner is careful to point out that this study only scratches the surface of the brain processes involved in intergroup reactions such as stigma – the way the brain processes social motivations is much more complex and needs further study.

“People shouldn’t over-generalize from this specific finding,” he said, noting that his sample of 40 Mexican-American students, although not small for a brain imaging study, represents only a small segment of a much more diverse community. . When his lab is back up and running after the COVID-19 shutdown, he said, he and his collaborators hope to study a larger sample of non-students.

Other members of Ratner’s research team include senior author and former UCSB postdoctoral fellow B. Locke Welborn and current UCSB doctorate. student Youngki Hong.



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