User:Mtillman6/Neuroscience and Race

A neurological look at race is multifaceted. Neurological studies have shown that everyone has an initial racial bias in the amygdala, but other parts in the brain regulate this initial negative bias. Also, scientists have been able to neurologically analyze the cross-race effect to understand the brain’s processing while viewing same-race and other-race faces. These neurological insights show that there are ways that racism and the cross-race effect can be reversed through exposure and changing cultural beliefs.

Neuroscientific Techniques
Scientists have just recently been able to study racial interactions from a neuroscience standpoint within the past few decades due to the rise in new neurological technologies. Studying the brain in racial interactions can be difficult because these interactions can be hard to replicate. Face recognition tests are the most commonly used method in studying racial interactions. These tests consist of observing own-race and other-race faces, and studying the brain's response to the faces. There are three major neurological techniques used to measure the brains response to these simulated racial interactions. Functional Magnetic Resonance Imaging (fMRI) measures the brain activity through measuring the blood oxygen level in the brain. This test gives insight into which regions of the brain are active during a certain event. Event-Related Potentials (ERPs) measure the brain's activity through measuring electrical impulses by electrodes on the head. This test gives insight in rapid changes in the brain. Transcranial Magnetic Stimulation (TMS) measures the response of a region of the brain once activated through magnetism. This test gives insight into causality of occurrences and gives specific insight in what the brain regions are doing. Brain-damaged patients have also been used to study racial interactions, by studying how racial interactions are affected when specific brain regions are damaged. These studies give insight into how the brain regions are involved in racial interactions. An implicit association test (IAC) is often used to measure the racial bias of people in studies by testing what objects, whether positive or negative, people associate with same-race or other-race faces.

Racism
Racism, prejudices, or stereotyping is a view or practice that categorizes one race as either superior or inferior. All people have a tendency to categorize other races, and this categorization can lead to internal beliefs about that race, which can lead to negative actions dealing with that race. Racial prejudices can be harmful to the victim, as well as the racist because racial interactions can induce a stress response, which if frequent, can break down muscle tissue and slow digestion. There have been several studies looking into which brain regions are involved in stereotyping and controlling these stereotypes.

Amygdala
The amygdala, which is the most researched brain region in racism studies, shows much greater activation while viewing other-race faces than same-race faces. This region of the brain is associated with fear conditioning, and has many connections with the cortex to control the body’s emotional response. There is often times variations in amygdala activation due to motivation and goals. The amygdala’s activation can be changed through not focusing on race or focusing on removing the racial bias. Patients with a damaged amygdala still show a racial bias, meaning that the amygdala isn’t the only region involved in activating a racial bias. Scientist believe that amygdala activation differences arise due to social/cultural perceptions and individual experiences.

Anterior Cingulate Cortex
The anterior cingulate cortex (ACC) is associated with detecting conflict and determining how to resolve that conflict. It is believed to play a part in the controversy in one’s mind over personal racial biases and culturally equality norms. ACC activation is shown to increase when there’s an automatic negative response to an out-group, as shown in amygdala activation. The ACC is used to recognize the conflict between cultural expectations and the automatic negative response, and is the first step in expressing racial attitudes.

Dorsolateral prefrontal cortex
The Dorsolateral prefrontal cortex (DLPFC) works in conjunction with the ACC, and acts as the overseer of the reaction to the racial conflict. It is the main region activated in top-down processing. The DLPFC controls the emotional response through interactions with the amygdala connected through the ventromedial prefrontal cortex. The DLPFC suppresses the amygdala activity to lower the initial racial bias and resolve the conflict. Suppression of the DLPFC through TMS techniques has made the patients increase their expression of racial bias. The DLPFC function is determined by internal beliefs and awareness of societal attitudes.

Corrections
Though there is an innate initial negative response while viewing other-race faces, the brain regions that control this response are malleable. The ACC and DLPFC both regulate the amygdala’s initial negative response. Many studies show that the initial racial bias can be changed through different situational contexts and motivations. Also, increased exposure to other races and cultural ideals help suppress the racial bias within the brain circuitry. Current studies in positive psychology have shown that denial of racial differences just leads to more racial stereotyping. However, the best way to control racism is to acknowledge racial differences, but to accept racial equality.

Cross-Race Effect
Many studies researching racial interactions analyze the Cross-race effect. This is a bias or tendency for people to be more familiar with a face of the same race compared to members of another race. This phenomenon is rooted in the differences in memory processing of same-race and other race faces.

Facial Recognition
The first step the brain does to encode a memory is to process the face. The lateral fusiform gyrus is a facial recognition area of the brain. Within this brain region, the fusiform face area (FFA) analyzes the configuration and holistic appearance of the face. The FFA is more activated when viewing same-race faces compared to other-race faces. As time progresses from when the face is first viewed, the differences in FFA activation diminish. It’s believed that the FFA is more activated when viewing a same-race face because the brain individuates (more analytical power needed) the same-race faces but just categorizes other-race faces. The FFA isn’t the only region involved in facial recognition that effects the cross-race effect, but also the whole ventral temporal (VT) cortex. Scientists are able to distinguish which race face you are looking at just by viewing your VT cortex. The fusiform cortex plays a vital role in categorizing race faces. This section is also more activated when viewing same-race faces, as it is studying the face in greater detail. However, these differences in activation of the fusiform complex diminish when a familiar other-race face is shown, like a celebrity.

Memory
Top-down and bottom-up processing are terms used to describe the differences in memory processing when observing same-race and other-race faces. Bottom-up processing puts together pieces of a whole and develops one grand picture. Top-down processing uses more initial cognitive work by breaking down the whole picture into pieces, and then analyzing those pieces. Bottom-up processing is used in processing same-race faces, and requires much less brain activation than top-down processing, which is used while processing other-race faces. Once the face is perceived by the VT cortex, the hippocampus is used to encode the memory in the parietal lobe. Overall, same-race faces undergo better memory encoding processes than other-race faces because they are remembered more often, however, other-race faces that are remembered undergo a more effortful memory encoding process. More brain activation is needed to effectively encode an other-race face. Memory encoding isn't the only found cause of the cross-race effect, but memory retrieval is also involved. In retrieving a memory, the parietal lobe is reactivated. When retrieving an other-race face, there is more reactivation of the parietal lobe, meaning more effort is needed to retrieve an other race fame memory. The frontal lobe is also activated while observing other-race faces if the parietal lobe is unable to retrieve the memory, acting as a search engine in the brain looking for the location of the memory.

Theories of Origin
There are two main theories that attempt to explain the origin of the cross-race effect: the perceptual expertise hypothesis and the social cognitive hypothesis. The perceptual expertise hypothesis states that the cross-race effect is due to lack of exposure to other cultures, and is not hard-wired. Strong evidence for this hypothesis is a decreasing cross-race effect in immigrants that have been assimilated within a culture for a few years. Another finding in support of this hypothesis is the reversibility of the cross-race effect in ethnic adopted children. The social cognitive hypothesis states that the cross-race effect is a result of a participants internal beliefs and prejudices acting on the face processing and memory functions of the brain. Evidence for this hypothesis is a higher activation of the amygdala and other areas of the brain involved with attitudes and evaluations when first viewing an other-race face. The categorization-individualization model, which is a newer theory, states that the cross-race effect is due the merging of social categorization, motivated individuation, and perceptual experience. There’s very convincing evidence that all of these factors play a role in the cross-race effect.

Anatomical Differences
There has been limited research on actual neurological differences among ethnic groups. This is believed to be due to low participation in experiments by minority groups. However, some research has shown some biological differences in brain anatomy among ethnic groups. There have been observed morphological differences between Caucasian and Chinese individuals in the frontal, parietal, and temporal brain regions. Most of these differences are believed to be due to environmental differences, such as differences in language development. It is observed that African Americans have a larger orbitofrontal cortex than Caucasians. The biological significance of these findings is unclear, but these findings are important for neurological studies that will investigate minority groups.