Neuroscience and race

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A neurological look at race is multifaceted. The cross-race effect has been neurologically explained by there being differences in brain processing while viewing same-race and other-race faces. [1] There is a debate over the cause of the cross-race effect.

Contents

Techniques

Neurotechnology enables studying the brain and racial interactions, though this study can be difficult because these interactions can be hard to replicate. Face recognition tests are the most commonly used method in studying racial interactions. [2] [3] [4] 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 brain's 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 the causality of occurrences and gives specific insight in what the brain regions are doing. [4] 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 different brain regions are involved in racial interactions once certain regions have been damaged. [5] 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. [3]

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 is characterized by people performing poorly on face recognition tests with other-race faces. This phenomenon is rooted in differences in face recognition and 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. [1] Within this brain region, the fusiform face area (FFA) analyzes the configuration and holistic appearance of the face. [4] 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 (using more analytic power) the same-race faces while simply categorizing 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 cortex (VT cortex). Scientists are able to distinguish which race face one is viewing at simply by viewing the VT cortex. [6] Additionally, 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. [4] However, these differences in activation of the fusiform complex diminish when a familiar other-race face is shown, like a celebrity. [7]

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. When bottom-up brain processing is used while viewing same-race faces, a holistic face in perceived, encoded and remembered. When top-down brain processing is used while viewing other-race faces, only features of the face are perceived and encoded. [8] 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; 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 face 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. [2]

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 assimilated to a culture for a few years. [2] Another finding in support of this hypothesis is the reversibility of the cross-race effect in ethnic adopted children. [9] 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. [10] The categorization-individualization model, which is a newer theory, states that the cross-race effect is due to 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. [11]

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. [1] [3] [12] This region of the brain is associated with fear conditioning, and has many connections with the cortex to control the body’s emotional response. [3] Often, there is variation 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. [1] Scientists believe that amygdala activation differences arise due to social/cultural perceptions and individual experiences. [12] However, it is important to note that 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. [5] The link between the amygdala and racial prejudice has been comprehensively reviewed. [13]

Collaboration of brain areas in responding to other-race faces. Amygdala signals to the ACC. The ACC and DLPFC communicate with each other. The DLPFC controls the amygdala. Brain Racism Complex.jpg
Collaboration of brain areas in responding to other-race faces. Amygdala signals to the ACC. The ACC and DLPFC communicate with each other. The DLPFC controls the amygdala.

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 cultural equality norms. ACC activation increases when a person has an automatic negative response to an out-group member, 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. [3]

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. [4] The DLPFC function is determined by internal beliefs and awareness of societal attitudes. [3]

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. [3] Differences in amygdala activation have diminished when other-race faces of famous or respected people are viewed, showing that amygdala activation can be controlled through personal beliefs. [14] Also, increased exposure to other races and cultural ideals help suppress the racial bias within the brain circuitry. For instance, one study showed that Asian immigrants who lived in America for an extended time showed an absence of the cross-race effect to other American faces, implying that exposure to other races decreases the effects of the cross-race effect. [2] Current studies in positive psychology have shown that denial of racial differences leads only to further racial stereotyping. Therefore, the best way to control racism is to acknowledge racial differences, and to accept racial equality. [15] Emotional regulation techniques are needed to overcome some racist beliefs, which involves emotionally reinterpreting events. [3] Behavior enhancer drugs could possibly be used in the future to modify people's racist response, but there are ethical arguments against this. [16]

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[ citation needed ]. However, some research has shown some differences in brain anatomy among ethnic groups. The causes are discussed in the context of sampling difficulties, racism, socioeconomic status, and differences in health outcomes. [17] [18] There have been observed morphological differences between European American and Chinese individuals in the frontal, parietal, and temporal brain regions. [18] [19] These differences are thought to be due to the effects of language differences on brain development. [19] [20] A 2010 study on variability in frontotemporal brain structure between African Americans and European Americans found differences in brain structure, despite the participants all being from an English speaking nation. However, these differences were small in nature, and most failed to survive a Bonferroni correction. The results can only be considered preliminary, as it only had 25 African American participants, and did not account for any confounds like health or socioeconomic status. [17]

Related Research Articles

<span class="mw-page-title-main">Amygdala</span> Each of two small structures deep within the temporal lobe of complex vertebrates

The amygdala is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex vertebrates, including humans. Shown to perform a primary role in the processing of memory, decision making, and emotional responses, the amygdalae are considered part of the limbic system. The term "amygdala" was first introduced by Karl Friedrich Burdach in 1822.

<span class="mw-page-title-main">Limbic system</span> Set of brain structures involved in emotion and motivation

The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.

<span class="mw-page-title-main">Face perception</span> Cognitive process of visually interpreting the human face

Facial perception is an individual's understanding and interpretation of the face. Here, perception implies the presence of consciousness and hence excludes automated facial recognition systems. Although facial recognition is found in other species, this article focuses on facial perception in humans.

<span class="mw-page-title-main">Visual memory</span> Ability to process visual and spatial information

Visual memory describes the relationship between perceptual processing and the encoding, storage and retrieval of the resulting neural representations. Visual memory occurs over a broad time range spanning from eye movements to years in order to visually navigate to a previously visited location. Visual memory is a form of memory which preserves some characteristics of our senses pertaining to visual experience. We are able to place in memory visual information which resembles objects, places, animals or people in a mental image. The experience of visual memory is also referred to as the mind's eye through which we can retrieve from our memory a mental image of original objects, places, animals or people. Visual memory is one of several cognitive systems, which are all interconnected parts that combine to form the human memory. Types of palinopsia, the persistence or recurrence of a visual image after the stimulus has been removed, is a dysfunction of visual memory.

Affective neuroscience is the study of how the brain processes emotions. This field combines neuroscience with the psychological study of personality, emotion, and mood. The basis of emotions and what emotions are remains an issue of debate within the field of affective neuroscience.

<span class="mw-page-title-main">Executive functions</span> Cognitive processes necessary for control of behavior

In cognitive science and neuropsychology, executive functions are a set of cognitive processes that are necessary for the cognitive control of behavior: selecting and successfully monitoring behaviors that facilitate the attainment of chosen goals. Executive functions include basic cognitive processes such as attentional control, cognitive inhibition, inhibitory control, working memory, and cognitive flexibility. Higher-order executive functions require the simultaneous use of multiple basic executive functions and include planning and fluid intelligence.

<span class="mw-page-title-main">Fusiform face area</span> Part of the human visual system that is specialized for facial recognition

The fusiform face area is a part of the human visual system that is specialized for facial recognition. It is located in the inferior temporal cortex (IT), in the fusiform gyrus.

<span class="mw-page-title-main">Ventromedial prefrontal cortex</span> Body part

The ventromedial prefrontal cortex (vmPFC) is a part of the prefrontal cortex in the mammalian brain. The ventral medial prefrontal is located in the frontal lobe at the bottom of the cerebral hemispheres and is implicated in the processing of risk and fear, as it is critical in the regulation of amygdala activity in humans. It also plays a role in the inhibition of emotional responses, and in the process of decision-making and self-control. It is also involved in the cognitive evaluation of morality.

<span class="mw-page-title-main">Dorsolateral prefrontal cortex</span> Area of the prefrontal cortex of primates

The dorsolateral prefrontal cortex is an area in the prefrontal cortex of the primate brain. It is one of the most recently derived parts of the human brain. It undergoes a prolonged period of maturation which lasts into adulthood. The DLPFC is not an anatomical structure, but rather a functional one. It lies in the middle frontal gyrus of humans. In macaque monkeys, it is around the principal sulcus. Other sources consider that DLPFC is attributed anatomically to BA 9 and 46 and BA 8, 9 and 10.

The cross-race effect is the tendency to more easily recognize faces that belong to one's own racial group, or racial groups that one has been in contact with. In social psychology, the cross-race effect is described as the "ingroup advantage," whereas in other fields, the effect can be seen as a specific form of the "ingroup advantage" since it is only applied in interracial or inter-ethnic situations. The cross-race effect is thought to contribute to difficulties in cross-race identification, as well as implicit racial bias.

Memory and trauma is the deleterious effects that physical or psychological trauma has on memory.

Recognition memory, a subcategory of explicit memory, is the ability to recognize previously encountered events, objects, or people. When the previously experienced event is reexperienced, this environmental content is matched to stored memory representations, eliciting matching signals. As first established by psychology experiments in the 1970s, recognition memory for pictures is quite remarkable: humans can remember thousands of images at high accuracy after seeing each only once and only for a few seconds.

Memory supports and enables social interactions in a variety of ways. In order to engage in successful social interaction, people must be able to remember how they should interact with one another, whom they have interacted with previously, and what occurred during those interactions. There are a lot of brain processes and functions that go into the application and use of memory in social interactions, as well as psychological reasoning for its importance.

The self-reference effect is a tendency for people to encode information differently depending on whether they are implicated in the information. When people are asked to remember information when it is related in some way to themselves, the recall rate can be improved.

<span class="mw-page-title-main">Parental brain</span>

Parental experience, as well as changing hormone levels during pregnancy and postpartum, cause changes in the parental brain. Displaying maternal sensitivity towards infant cues, processing those cues and being motivated to engage socially with her infant and attend to the infant's needs in any context could be described as mothering behavior and is regulated by many systems in the maternal brain. Research has shown that hormones such as oxytocin, prolactin, estradiol and progesterone are essential for the onset and the maintenance of maternal behavior in rats, and other mammals as well. Mothering behavior has also been classified within the basic drives.

Emotion perception refers to the capacities and abilities of recognizing and identifying emotions in others, in addition to biological and physiological processes involved. Emotions are typically viewed as having three components: subjective experience, physical changes, and cognitive appraisal; emotion perception is the ability to make accurate decisions about another's subjective experience by interpreting their physical changes through sensory systems responsible for converting these observed changes into mental representations. The ability to perceive emotion is believed to be both innate and subject to environmental influence and is also a critical component in social interactions. How emotion is experienced and interpreted depends on how it is perceived. Likewise, how emotion is perceived is dependent on past experiences and interpretations. Emotion can be accurately perceived in humans. Emotions can be perceived visually, audibly, through smell and also through bodily sensations and this process is believed to be different from the perception of non-emotional material.

Accents are the distinctive variations in the pronunciation of a language. They can be native or foreign, local or national and can provide information about a person’s geographical locality, socio-economic status and ethnicity. The perception of accents is normal within any given group of language users and involves the categorisation of speakers into social groups and entails judgments about the accented speaker, including their status and personality. Accents can significantly alter the perception of an individual or an entire group, which is an important fact considering that the frequency that people with different accents are encountering one another is increasing, partially due to inexpensive international travel and social media. As well as affecting judgments, accents also affect key cognitive processes that are involved in a myriad of daily activities. The development of accent perception occurs in early childhood. Consequently, from a young age accents influence our perception of other people, decisions we make about when and how to interact with others, and, in reciprocal fashion, how other people perceive us. A better understanding of the role accents play in our appraisal of individuals and groups, may facilitate greater acceptance of people different from ourselves and lessen discriminatory attitudes and behavior.

The neurocircuitry that underlies executive function processes and emotional and motivational processes are known to be distinct in the brain. However, there are brain regions that show overlap in function between the two cognitive systems. Brain regions that exist in both systems are interesting mainly for studies on how one system affects the other. Examples of such cross-modal functions are emotional regulation strategies such as emotional suppression and emotional reappraisal, the effect of mood on cognitive tasks, and the effect of emotional stimulation of cognitive tasks.

Social cognitive neuroscience is the scientific study of the biological processes underpinning social cognition. Specifically, it uses the tools of neuroscience to study "the mental mechanisms that create, frame, regulate, and respond to our experience of the social world". Social cognitive neuroscience uses the epistemological foundations of cognitive neuroscience, and is closely related to social neuroscience. Social cognitive neuroscience employs human neuroimaging, typically using functional magnetic resonance imaging (fMRI). Human brain stimulation techniques such as transcranial magnetic stimulation and transcranial direct-current stimulation are also used. In nonhuman animals, direct electrophysiological recordings and electrical stimulation of single cells and neuronal populations are utilized for investigating lower-level social cognitive processes.

The eye-contact effect is a psychological phenomenon in human selective attention and cognition. It is the effect that the perception of eye contact with another human face has on certain mechanisms in the brain. This contact has been shown to increase activation in certain areas of what has been termed the ‘social brain’. This social brain network processes social information as the face, theory of mind, empathy, and goal-directedness.

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