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New research reveals the effect of stigma on brain processing

New research reveals the effect of stigma on brain processing

For the past several months, multiple cities in the US have seen massive protests erupt following the deaths of George Floyd, Breonna Taylor, Ahmaud Arbery, and Tony McDade. The brutal killings of these unarmed individuals gave impetus to the Black Lives Movement bringing the conversation about the treatment of people of color and other minorities, front and center on the national stage.

Assistant professor of psychological and brain sciences at UC Santa Barbara, Kyle Ratner is interested in finding out how social and biological factors cause intergroup bias and feelings of stigmatization. “What we’re 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,” he says.

Ratner believes that people belonging to historically marginalized groups in the United States have to deal with troublesome stressors in addition to the everyday stressors that people belonging to non-disadvantaged groups bear. He goes on to cite the examples of overt racism, stigmatizing depiction in the media, and systemic discrimination that causes hurdles in many aspects of life, from finding jobs, education, healthcare, housing, and legal matters.

Alarmed by the prevalence of negative stereotypes of Latinx people, Ratner and his colleagues set out to explore the impact of stigmatization on Mexican American students and how it can influence the brain in processing information.

A new paper published in the Journal Social Cognitive and Affective Neuroscience investigates how experiencing negative stereotypes can affect responses to monetary stimulus. The findings suggest that exposure to stigmatization alters the way Mexican American students anticipate rewards and punishments in comparison to those who are not exposed to this ordeal.

Ratner claimed his research’s findings could provide a stepping stone for future scientists to study the neural pathways affected by experiencing stigma and determine their influence on the psychological and physical health of the individuals.

So far research has focused on how feelings of stigmatization and discrimination can trigger anger, racing thoughts, and a state of high alert. Although Ratner accepts that people do experience these states in some contexts, his research work is centered on the mental exhaustion of hearing a constant negative rhetoric against the group an individual belongs to.

He describes psychological fatigue of being the target of negative stereotypes as one of the reactions to the stress of detangling one’s identity from widely accepted public perceptions of the community one belongs to.

In previous research that he worked on almost a decade ago, Ratner showed that life stress can be linked to anhedonia which is dulled sensitivity to positive and rewarding information such as winning a prize. “If you’re not sensitive to the rewarding things in life, you’re basically left being sensitive to all the frustrating things in life, without that positive buffer. And that’s one route to depression,” he said.

Keeping in view that enduring years of stigma can produce a similar sense of withdrawal and resignation, Ratner and his team considered experiencing stigma as a social stressor. The team went on to determine whether negative stereotype exposure affects sensitivity to rewards in a similar manner.

The researchers focused on the nucleus accumbens a subcortical brain region that performs a central role in anticipating pressure — the stage of “wanting” of reward processing that influences behaviors. By using functional MRI to monitor brain activity, the researchers asked Mexican American UCSB students to watch a set of video clips in quick succession and then presented the students with an opportunity to win money or avoid losing money.

As a control group, some viewers were shown news and documentary clips of social problems in the US of the country in general such as childhood obesity, teen pregnancy, gang violence, and low high school graduation numbers.

In the stigmatized group, students watched news and documentary clips based on the same four problems but targeting the Latinx community as the group particularly at risk in these scenarios. The videos were not overtly racist, rather the videos leaned towards spending a disproportionate amount of attention on the link between certain social issues and their effects on Latinx people instead of presenting them as problems relevant to the US as a whole.

The clips appeared to be from mainstream news agencies and the narrators appeared to be reporting simple facts, however, the content of the videos showcased negative stereotypes. Following repeated exposure to negative stereotypes, the students were asked to perform a Monetary Incentive Delay (MID) task. The task required them to push a button every time they saw a star on the screen. By pressing the button as fast as possible they could either win money or avoid losing money.

The participants who were shown the stigmatizing videos showed the nucleus accumbens responding differently while waiting for the star to appear in comparison to the control group. The pattern of neural activity observed suggests that negative stereotype exposure affected how the students anticipated winning or losing money.

The group that watched the stigmatizing video also showed lower levels of arousal just before starting the MID task fortifying the theory that stigmatizing experiences can have a demotivating effect. “The nucleus accumbens is very important for motivated behavior, and sparks of motivation are important for many aspects for everyday life,” Ratner commented. A loss of motivation is usually experienced by those who believe their situation is out of their control.

The research points towards the problematic nature of depicting negative stereotypes in the media and popular culture by showing that they can make people feel stigmatized even if they do not experience discrimination in their daily life. “It becomes something you can’t escape — similar to other stressors that are out of people’s control and have been shown to cause anhedonia,” Ratner explained.

While the researchers consider their findings significant they are aware of the limitations of the study and accept that their remains much to explore. The research gives a faint idea of the brain processes at play in intergroup reactions such as stigma and more research is required to determine how the brain processes social motivations.

Ratner is wary of people taking his research to generalize too much and is quick to point that his sample comprised 40 Mexican American college students which is an acceptable number for a brain imagining study but still represents a small section of a very diverse community. He hopes to study larger non-student samples once his lab resumes working following COVID-19 related cessation.


Kyle G Ratner, Youngki Hong, B Locke Welborn. Exposure to negative stereotypes influences representations of monetary incentives in the nucleus accumbens. Social Cognitive and Affective Neuroscience, 2020; 15 (3): 347 DOI: 10.1093/scan/nsaa041

Written by Farwa Batool

MSc Biotechnology.
Writer and a mom of two beautiful daughters.

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