Differential response in the human amygdala to racial outgroup vs ingroup face stimuli

Police discrimination and police distrust among ethnic minority adolescents in Germany

In light of ongoing debates about racially motivated police violence, this paper examines two separate but interrelated phenomena: instances of police discrimination and mistrust in police and the judicial system among ethnic minorities in Germany. Analyses are carried out based on waves 1, 3, and 5 of the CILS4EU-DE data collected among 14 to 20 year-old respondents in Germany. The focus of the paper lies on young men from the Middle East, as well as Northern and Sub-Saharan Africa, who-as our study demonstrates-tend to disproportionally more often report discrimination experiences and particularly low levels of trust in police and courts compared to other ethnic minorities and the majority populations in Germany, and partially also in comparison to their female counterparts. We also show that more frequent experiences of police discrimination are associated with greater distrust of the police and partially also with courts among young men from the Middle East, North and Sub-Saharan Africa. Female adolescents from similar backgrounds are also more distrustful of the police, but this is not explained by their own experiences of police discrimination.

Pre-scan state anxiety is associated with greater right amygdala-hippocampal response to fearful versus happy faces among trait-anxious Latina girls

BACKGROUND

Unfamiliarity with academic research may contribute to higher levels of anticipatory state anxiety about affective neuroimaging tasks. Children with high trait anxiety display differences in brain response to fearful facial affect compared to non-anxious youth, but little is known about the influence of state anxiety on this association. Because reduced engagement in scientific research and greater mistrust among minoritized groups may lead to systematic differences in pre-scan state anxiety, it is crucial to understand the neural correlates of state anxiety during emotion processing so as to disambiguate sources of individual differences.

METHODS

The present study probed the interactive effects of pre-scan state anxiety, trait anxiety, and emotional valence (fearful vs. happy faces) on neural activation during implicit emotion processing in a community sample of 46 preadolescent Latina girls (8-13 years).

RESULTS

Among girls with mean and high levels of trait anxiety, pre-scan state anxiety was associated with greater right amygdala-hippocampal and left inferior parietal lobe response to fearful faces relative to happy faces.

CONCLUSIONS

Anticipatory state anxiety in the scanning context may cause children with moderate and high trait anxiety to be hypervigilant to threats, further compounding the effects of trait anxiety. Neuroimaging researchers should control for state anxiety so that systematic differences in brain activation resulting from MRI apprehension are not misleadingly attributed to demographic or environmental characteristics.

The effects of experience of discrimination and acculturation during pregnancy on the developing offspring brain

The experience of ethnic, racial, and structural inequalities is increasingly recognized as detrimental to health, and early studies suggest that its experience in pregnant mothers may affect the developing fetus. We characterized discrimination and acculturation experiences in a predominantly Hispanic sample of pregnant adolescent women and assessed their association with functional connectivity in their neonate's brain. We collected self-report measures of acculturation, discrimination, maternal distress (i.e., perceived stress, childhood trauma, and depressive symptoms), and socioeconomic status in 165 women. Then, we performed a data-driven clustering of acculturation, discrimination, perceived stress, depressive symptoms, trauma, and socioeconomic status variables during pregnancy to determine whether discrimination or acculturation clustered into distinct factors. Discrimination and acculturation styles loaded onto different factors from perceived stress, depressive symptoms, trauma, and socioeconomic status, suggesting that they were distinct from other factors in our sample. We associated these data-driven maternal phenotypes (discrimination and acculturation styles) with measures of resting-state functional MRI connectivity of the infant amygdala (n = 38). Higher maternal report of assimilation was associated with weaker connectivity between their neonate's amygdala and bilateral fusiform gyrus. Maternal experience of discrimination was associated with weaker connectivity between the amygdala and prefrontal cortex and stronger connectivity between the amygdala and fusiform of their neonate. Cautiously, the results may suggest a similarity to self-contained studies with adults, noting that the experience of discrimination and acculturation may influence amygdala circuitry across generations. Further prospective studies are essential that consider a more diverse population of minoritized individuals and with a comprehensive assessment of ethnic, racial, and structural factors.

Distinct patterns of neural response to faces from different races in humans and deep networks

Social categories such as the race or ethnicity of an individual are typically conveyed by the visual appearance of the face. The aim of this study was to explore how these differences in facial appearance are represented in human and artificial neural networks. First, we compared the similarity of faces from different races using a neural network trained to discriminate identity. We found that the differences between races were most evident in the fully connected layers of the network. Although these layers were also able to predict behavioural judgements of face identity from human participants, performance was biased toward White faces. Next, we measured the neural response in face-selective regions of the human brain to faces from different races in Asian and White participants. We found distinct patterns of response to faces from different races in face-selective regions. We also found that the spatial pattern of response was more consistent across participants for own-race compared to other-race faces. Together, these findings show that faces from different races elicit different patterns of response in human and artificial neural networks. These differences may underlie the ability to make categorical judgements and explain the behavioural advantage for the recognition of own-race faces.

Structural inequities contribute to racial/ethnic differences in neurophysiological tone, but not threat reactivity, after trauma exposure

Considerable racial/ethnic disparities persist in exposure to life stressors and socioeconomic resources that can directly affect threat neurocircuitry, particularly the amygdala, that partially mediates susceptibility to adverse posttraumatic outcomes. Limited work to date, however, has investigated potential racial/ethnic variability in amygdala reactivity or connectivity that may in turn be related to outcomes such as post-traumatic stress disorder (PTSD). Participants from the AURORA study (n = 283), a multisite longitudinal study of trauma outcomes, completed functional magnetic resonance imaging and psychophysiology within approximately two-weeks of trauma exposure. Seed-based amygdala connectivity and amygdala reactivity during passive viewing of fearful and neutral faces were assessed during fMRI. Physiological activity was assessed during Pavlovian threat conditioning. Participants also reported the severity of posttraumatic symptoms 3 and 6 months after trauma. Black individuals showed lower baseline skin conductance levels and startle compared to White individuals, but no differences were observed in physiological reactions to threat. Further, Hispanic and Black participants showed greater amygdala connectivity to regions including the dorsolateral prefrontal cortex (PFC), dorsal anterior cingulate cortex, insula, and cerebellum compared to White participants. No differences were observed in amygdala reactivity to threat. Amygdala connectivity was associated with 3-month PTSD symptoms, but the associations differed by racial/ethnic group and were partly driven by group differences in structural inequities. The present findings suggest variability in tonic neurophysiological arousal in the early aftermath of trauma between racial/ethnic groups, driven by structural inequality, impacts neural processes that mediate susceptibility to later PTSD symptoms.

Uncertain threat is associated with greater impulsive actions and neural dissimilarity to Black versus White faces

Race is a social construct that contributes to group membership and heightens emotional arousal in intergroup contexts. Little is known about how emotional arousal, specifically uncertain threat, influences behavior and brain processes in response to race information. We investigated the effects of experimentally manipulated uncertain threat on impulsive actions to Black versus White faces in a community sample (n = 106) of Black and White adults. While undergoing fMRI, participants performed an emotional go/no-go task under three conditions of uncertainty: 1) anticipation of an uncertain threat (i.e., unpredictable loud aversive sound); 2) anticipation of an uncertain reward (i.e., unpredictable receipt of money); and 3) no anticipation of an uncertain event. Representational similarity analysis was used to examine the neural representations of race information across functional brain networks between conditions of uncertainty. Participants-regardless of their own race-showed greater impulsivity and neural dissimilarity in response to Black versus White faces across all functional brain networks in conditions of uncertain threat relative to other conditions. This pattern of greater neural dissimilarity under threat was enhanced in individuals with high implicit racial bias. Our results illustrate the distinct and important influence of uncertain threat on global differentiation in how race information is represented in the brain, which may contribute to racially biased behavior.

Community-level explicit racial prejudice potentiates whites' neural responses to black faces: A spatial meta-analysis

We evaluated the hypothesis that neural responses to racial out-group members vary systematically based on the level of racial prejudice in the surrounding community. To do so, we conducted a spatial meta-analysis, which included a comprehensive set of studies (k = 22; N = 481). Specifically, we tested whether community-level racial prejudice moderated neural activation to Black (vs. White) faces in primarily White participants. Racial attitudes, obtained from Project Implicit, were aggregated to the county (k = 17; N = 10,743) in which each study was conducted. Multi-level kernel density analysis demonstrated that significant differences in neural activation to Black (vs. White) faces in right amygdala, dorsal anterior cingulate cortex, and dorsolateral prefrontal cortex were detected more often in communities with higher (vs. lower) levels of explicit (but not implicit) racial prejudice. These findings advance social-cognitive neuroscience by identifying aspects of macro-social contexts that may alter neural responses to out-group members.

Encoding of Race Categories by Single Neurons in the Human Brain

Previous research has suggested that race-specific features are automatically processed during face perception, often with out-group faces treated categorically. Functional imaging has illuminated the hemodynamic correlates of this process, with fewer studies examining single-neuron responses. In the present experiment, epilepsy patients undergoing microwire recordings in preparation for surgical treatment were shown realistic computer-generated human faces, which they classified according to the emotional expression shown. Racial categories of the stimulus faces varied independently of the emotion shown, being irrelevant to the patients’ primary task. Nevertheless, we observed race-driven changes in neural firing rates in the amygdala, anterior cingulate cortex, and hippocampus. These responses were broadly distributed, with the firing rates of 28% of recorded neurons in the amygdala and 45% in the anterior cingulate cortex predicting one or more racial categories. Nearly equal proportions of neurons responded to White and Black faces (24% vs. 22% in the amygdala and 26% vs. 28% in the anterior cingulate cortex). A smaller fraction (12%) of race-responsive neurons in the hippocampus predicted only White faces. Our results imply a distributed representation of race in brain areas involved in affective judgments, decision making, and memory. They also support the hypothesis that race-specific cues are perceptually coded even when those cues are task-irrelevant.

Ethnic differences in behavioral and physiological indicators of sensitivity to threat

The clinical presentation of anxiety may differ between Hispanics/Latinx (H/L) and non-H/L, although findings on ethnic differences in self-reported anxiety symptoms have been mixed. Fewer studies have focused on ethnic differences in quick and relatively automatic laboratory-assessed indicators of anxiety symptoms, which have the potential to be more objective indicators than self-report. Therefore, the present study examined ethnic differences in two laboratory-assessed indicators of threat sensitivity (an important transdiagnostic mechanism of anxiety): attentional bias to threat and electromyography startle reactivity to threat. White H/L (n = 117) and White non-H/L (n = 168) adults who were matched on demographics and lifetime psychopathology (including anxiety) completed a dot-probe task to assess attentional bias to threat and the No-Predictable-Unpredictable threat (NPU) task to assess startle reactivity to threat. Results indicated that H/L displayed less Slow OrientationRB (β = -0.27, p = 0.032, R2β∗ = 0.02), and increased Slow DisengagementRB (β = 0.31, p = 0.016, R2β∗ = 0.02) compared to non-H/L. H/L exhibited blunted overall startle compared to non-H/L (β = -0.30, p = 0.014, R2β∗ = 0.02), but groups did not differ in startle reactivity to either predictable or unpredictable threat. In summary, H/L and non-H/L may differ in their experience and presentation of anxiety symptoms and such differences may vary across indicators of sensitivity to threat.

Learning positive social information reduces racial bias as indexed by N400 response

The present study used EEG/ERPs to detect the activation of implicit stereotypical representations associated to other-race (OR) people and the modulation of such activation through the previous presentation of positive vs. neutral social information. Electrophysiological signals were recorded in 40 Italian Caucasian participants, unaware of the overall study's purpose. They were presented with 285 sentences that could either violate, non-violate (e.g., "the Roma girl was involved in a robbery) or be neutral with regard to stereotypical concepts concerning other-race people (e.g. Asians, Africans, Arabic). ERPs were time-locked to the terminal words. Prior to the sentence reading task, participants were exposed to a 10 minutes colourful video documentary. While the experimental group was presented a video containing images picturing other-race characters involved in "prestigious" activities that violated stereotypical negative assumptions (e.g. a black neurosurgeon leading a surgery team), the control group viewed a neutral documentary about flora and fauna. EEG signals were then recorded during the sentence reading task to explore whether the previous exposure to the experimental video could modulate the detection of incongruence in the sentences violating stereotypes, as marked by the N400 response. A fictitious task was adopted, consisted in detecting rare animal names. Indeed, only the control group showed a greater N400 response (350-550 ms) to words incongruent with ethnic stereotypes compared to congruent and neutral ones, thus suggesting the presence of a racial bias. No N400 response was found for the experimental group, suggesting a lack of negative expectation for OR individuals. The swLORETA inverse solution, performed on the prejudice-related N400 showed that the Inferior Temporal and the Superior and Middle Frontal Gyri were the strongest N400 intra-cortical sources. Regardless of the experimental manipulation, Congruent terminal words evoked a greater P300 response (500-600 ms) compared to incongruent and neutral ones and a late frontal positivity (650-800 ms) was found to be larger to sentences involving OR than own-race characters (either congruent or incongruent with the prejudice) thus possibly indicating bias-free perceptual in-group/out-group categorization processes. The data showed how it is possible to modulate a pre-existing racial prejudice (as reflected by N400 effect) through exposure to positive media-driven information about OR people. Further follow-up studies should determine the duration in time, and across contexts, of this modulatory effect.

Effects of Oxytocin on Social Comparisons in Intergroup Situations

Oxytocin (OXT) is known to affect various social processes, including social comparisons and intergroup competition. In this study, we examined whether social comparisons in intergroup situations can be modulated by OXT and, if so, how this modulation manifests. Using a double-blind placebo-controlled design, we randomly assigned male participants to either OXT or placebo treatment and then asked them to play a card game with either an in-group or an out-group member. The OXT-treated participants showed a greater social comparison effect in the games with an out-group member than in games with an in-group member. Specifically, the participants in the OXT treatment condition showed a greater acceptance rate for relative gain (downward comparison) and a lower acceptance rate for relative loss (upward comparison) while playing with an out-group member rather than an in-group member. In contrast, no such effect was observed among placebo-treated participants. These findings demonstrate that OXT facilitates intergroup social comparisons with out-group versus in-group members.

The neural underpinnings of intergroup social cognition: an fMRI meta-analysis

Roughly 20 years of functional magnetic resonance imaging (fMRI) studies have investigated the neural correlates underlying engagement in social cognition (e.g. empathy and emotion perception) about targets spanning various social categories (e.g. race and gender). Yet, findings from individual studies remain mixed. In the present quantitative functional neuroimaging meta-analysis, we summarized across 50 fMRI studies of social cognition to identify consistent differences in neural activation as a function of whether the target of social cognition was an in-group or out-group member. We investigated if such differences varied according to a specific social category (i.e. race) and specific social cognitive processes (i.e. empathy and emotion perception). We found that social cognition about in-group members was more reliably related to activity in brain regions associated with mentalizing (e.g. dorsomedial prefrontal cortex), whereas social cognition about out-group members was more reliably related to activity in regions associated with exogenous attention and salience (e.g. anterior insula). These findings replicated for studies specifically focused on the social category of race, and we further found intergroup differences in neural activation during empathy and emotion perception tasks. These results help shed light on the neural mechanisms underlying social cognition across group lines.

Four dimensions characterize attributions from faces using a representative set of English trait words

People readily (but often inaccurately) attribute traits to others based on faces. While the details of attributions depend on the language available to describe social traits, psychological theories argue that two or three dimensions (such as valence and dominance) summarize social trait attributions from faces. However, prior work has used only a small number of trait words (12 to 18), limiting conclusions to date. In two large-scale, preregistered studies we ask participants to rate 100 faces (obtained from existing face stimuli sets), using a list of 100 English trait words that we derived using deep neural network analysis of words that have been used by other participants in prior studies to describe faces. In study 1 we find that these attributions are best described by four psychological dimensions, which we interpret as “warmth”, “competence”, “femininity”, and “youth”. In study 2 we partially reproduce these four dimensions using the same stimuli among additional participant raters from multiple regions around the world, in both aggregated and individual-level data. These results provide a comprehensive characterization of trait attributions from faces, although we note our conclusions are limited by the scope of our study (in particular we note only white faces and English trait words were included).

People form impressions about others from seeing their faces, and use many words to describe those impressions. Here, using ratings of 100 representatively sampled white adult faces on a large set of traits, the authors show that trait impressions from faces can be summarized by four psychological dimensions.

Processing of Task-Irrelevant Race Information is Associated with Diminished Cognitive Control in Black and White Individuals

The race of an individual is a salient physical feature that is rapidly processed by the brain and can bias our perceptions of others. How the race of others explicitly impacts our actions toward them during intergroup contexts is not well understood. In the current study, we examined how task-irrelevant race information influences cognitive control in a go/no-go task in a community sample of Black (n = 54) and White (n = 51) participants. We examined the neural correlates of behavioral effects using functional magnetic resonance imaging and explored the influence of implicit racial attitudes on brain-behavior associations. Both Black and White participants showed more cognitive control failures, as indexed by dprime, to Black versus White faces, despite the irrelevance of race to the task demands. This behavioral pattern was paralleled by greater activity to Black faces in the fusiform face area, implicated in processing face and in-group information, and lateral orbitofrontal cortex, associated with resolving stimulus-response conflict. Exploratory brain-behavior associations suggest different patterns in Black and White individuals. Black participants exhibited a negative association between fusiform activity and response time during impulsive errors to Black faces, whereas White participants showed a positive association between lateral OFC activity and cognitive control performance to Black faces when accounting for implicit racial associations. Together our findings propose that attention to race information is associated with diminished cognitive control that may be driven by different mechanisms for Black and White individuals.

Enhanced N170 to outgroup faces: Perceptual novelty or prejudice?

Habituation to ethnic ingroup members has been reported to be greater than to ethnic outgroup members. This pattern could be due to the lack of perceptive experience (familiarity) with outgroup facial morphs or, alternatively, to the prejudice held toward that outgroup. We explored this disjunctive in 71 participants, all Spanish, who were experimentally habituated to faces from their Ingroup and to faces from two unfamiliar outgroups, one for which there is low probability of prejudice in this population (Non-prejudiced Outgroup), and one for which the probability of prejudice is higher (Prejudiced Outgroup). We indexed habituation through event-related potentials, concretely as the differential amplitude of the face-sensitive N170 component from Initial to Final trials of each group. Afterward, participants completed several prejudice measures. N170 showed significant habituation to all faces, though it did not differ among groups. However, a regression analysis revealed that individual habituation to the Outgroup faces was inversely related to implicit prejudice scores. Importantly, N170 amplitudes were maximal for the Prejudiced Outgroup in both Initial and Final trials. We conclude that these effects are explained by the prejudice held toward a specific outgroup rather than perceptive experience.

A Call for Greater Attention to Culture in the Study of Brain and Development

Despite growing research on neurobiological development, little attention has been paid to cultural and ethnic variation in neurodevelopmental processes. We present an overview of the current state of developmental cognitive neuroscience with respect to its attention to cultural issues. Analyses based on 80 publications represented in five recent meta-analyses related to adolescent developmental neuroscience show that 99% of the publications used samples in Western countries. Only 22% of studies provided a detailed description of participants' racial/ethnic background, and only 18% provided for socioeconomic status. Results reveal a trend in developmental cognitive neuroscience research: The body of research is derived not only mostly from Western samples but also from participants whose race/ethnicity is unknown. To achieve a holistic perspective on brain development in different cultural contexts, we propose and highlight an emerging interdisciplinary approach-developmental cultural neuroscience-the intersection of developmental psychology, cultural psychology, and cognitive neuroscience. Developmental cultural neuroscience aims to elucidate cultural similarities and differences in neural processing across the life span. We call attention to the importance of incorporating culture into the empirical investigation of neurodevelopment.

Measuring implicit mental representations related to ethnic stereotypes with ERPs: An exploratory study

The present investigation used ERPs to detect the activation of implicit stereotypical representations associated to different ethnic groups, by means of an implicit paradigm. 285 sentences were presented to 20 Italian Caucasian participants while EEG signals were recorded from 128 scalp sites. Sentences could either violate (Incongruent condition), non-violate (Congruent condition) or be neutral (Neutral condition) with regard to stereotypical concepts concerning non-Caucasian ethnic groups (e.g. Asians, Africans, Arabs). No awareness or judgment about stereotypes was required. Participants were engaged in a fictitious task, ignoring the overall study's purpose. The results showed that Incongruent terminal words elicited a greater anterior N400 response (300-500 ms) compared to Congruent and Neutral words, reflecting a difficulty in integrating the information incongruent with pre-existing stereotypical knowledge. The participant's individual amplitude values of the N400-Difference Wave (Incongruent - Congruent), showed a direct correlation with the individual racism scores obtained at the Subtle and Blatant Prejudice Scale, administered at the end of the experimental session. Intra-cortical sources explaining the N400 involved areas of the social cognition network such as the medial frontal cortex (BA10) and the inferior temporal gyrus (BA20) which are known to support processing of information about other people and impression formation. Moreover, Congruent terminal words evoked a greater P300 response (500-600 ms) compared to the other conditions, possibly reflecting the merging of incoming inputs with anticipated semantic information. A late post-N400 frontal positivity (650-800 ms) was found to be larger to sentences concerning other-race characters (ether congruent or incongruent) compared to sentences involving own-race characters (neutral). The study corroborated the effectiveness of neurophysiological measures to assess implicit complex semantic representations and circumventing social desirability-related problems.

The neural basis of ideological differences in race categorization

Multiracial individuals are often categorized as members of their 'socially subordinate' racial group-a form of social discrimination termed hypodescent-with political conservatives more likely than liberals to show this bias. Although hypodescent has been linked to racial hierarchy preservation motives, it remains unclear how political ideology influences categorization: Do conservatives and liberals see, feel or think about mixed-race faces differently? Do they differ in sensitivity to Black prototypicality (i.e. skin tone darkness and Afrocentric features) or racial ambiguity (i.e. categorization difficulty) of Black/White mixed-race faces? To help answer these questions, we collected a politically diverse sample of White participants and had them categorize mixed-race faces as Black or White during functional neuroimaging. We found that conservatism was related to greater anterior insula activity to racially ambiguous faces, and this pattern of brain activation mediated conservatives' use of hypodescent. This demonstrates that conservatives' greater sensitivity to racial ambiguity (rather than Black prototypicality) gives rise to greater categorization of mixed-race individuals into the socially subordinate group and tentatively suggests that conservatives may differ from liberals in their affective reactions to mixed-race faces. Implications for the study of race categorization and political psychology are discussed. This article is part of the theme issue 'The political brain: neurocognitive and computational mechanisms'.

A combined fMRI and EMG study of emotional contagion following partial sleep deprivation in young and older humans

Sleep deprivation is proposed to inhibit top-down-control in emotion processing, but it is unclear whether sleep deprivation affects emotional mimicry and contagion. Here, we aimed to investigate effects of partial sleep deprivation on emotional contagion and mimicry in young and older humans. Participants underwent partial sleep deprivation (3 h sleep opportunity at the end of night), crossed-over with a full sleep condition in a balanced order, followed by a functional magnetic resonance imaging and electromyography (EMG) experiment with viewing of emotional and neutral faces and ratings of emotional responses. The final sample for main analyses was n = 69 (n = 36 aged 20–30 years, n = 33 aged 65–75 years). Partial sleep deprivation caused decreased activation in fusiform gyri for angry faces and decreased ratings of happiness for all stimuli, but no significant effect on the amygdala. Older participants reported more anger compared to younger participants, but no age differences were seen in brain responses to emotional faces or sensitivity to partial sleep deprivation. No effect of the sleep manipulation was seen on EMG. In conclusion, emotional contagion, but not mimicry, was affected by sleep deprivation. Our results are consistent with the previously reported increased negativity bias after insufficient sleep.

The Stockholm sleepy brain study: effects of sleep deprivation on cognitive and emotional processing in young and old. https://clinicaltrials.gov/ct2/show/NCT02000076.

Truth and lies in your eyes: Pupil dilation of White participants in truthful and deceptive responses to White and Black partners

In the present study, we examined the pupillary response of White participants who were asked to tell the truth or lie to White or Black partners. Research on cues to deception has assumed that lying is more cognitively demanding that truth telling. In line with this assumption, previous studies have shown that lying is associated with greater pupil dilation, a behavioral cue that typically manifests itself under conditions of stress or cognitive effort. In accordance with these results, we predicted greater pupil dilation when lying than when telling the truth. Furthermore, pupil dilation was expected to be greater when responding to White than Black partners. Finally, we hypothesized that pupil dilation would be greater when lying to White than Black partners. Participants were instructed to answer a set of questions, half truthfully and half deceptively. They were led to believe that White vs. Black partners (one male and one female) would ask the questions via computer connection. Indeed, we used feminine and masculine synthetic voices. Pupil dilation was assessed with a remote eye-tracking system. Results provided support for the first two hypotheses. However, the predicted interaction between race of partners and truth status of message (lying vs. telling the truth) was nonsignificant. Our findings highlight the importance of considering race in the study of truthful and deceptive communications.

A neurocognitive model of perceptual decision-making on emotional signals

Humans make various kinds of decisions about which emotions they perceive from others. Although it might seem like a split-second phenomenon, deliberating over which emotions we perceive unfolds across several stages of decisional processing. Neurocognitive models of general perception postulate that our brain first extracts sensory information about the world then integrates these data into a percept and lastly interprets it. The aim of the present study was to build an evidence-based neurocognitive model of perceptual decision-making on others' emotions. We conducted a series of meta-analyses of neuroimaging data spanning 30 years on the explicit evaluations of others' emotional expressions. We find that emotion perception is rather an umbrella term for various perception paradigms, each with distinct neural structures that underline task-related cognitive demands. Furthermore, the left amygdala was responsive across all classes of decisional paradigms, regardless of task-related demands. Based on these observations, we propose a neurocognitive model that outlines the information flow in the brain needed for a successful evaluation of and decisions on other individuals' emotions. HIGHLIGHTS: Emotion classification involves heterogeneous perception and decision-making tasks Decision-making processes on emotions rarely covered by existing emotions theories We propose an evidence-based neuro-cognitive model of decision-making on emotions Bilateral brain processes for nonverbal decisions, left brain processes for verbal decisions Left amygdala involved in any kind of decision on emotions.

Attentional saliency and ingroup biases: From society to the brain

There is ample evidence demonstrating intergroup biases on cognition and emotion. However, it remains unclear how exactly group identification influences these processes, with issues of context sensitivity and goal dependence remaining open to scrutiny. Providing a range of interdisciplinary material, the current review attempts to inform understanding of these issues. Specifically, we provide evidence revealing that individuals show enhanced attention for stimuli associated with an ingroup compared to an outgroup. At the attentional level, such biases can be explained by the assignment of different levels of saliency to ingroup versus outgroup targets. Critically, however, salience assignment is not fixed but varies as a function of context and goal-directed behavior. We suggest that the network in the brain previously associated with social and emotional saliency and attention - notably the anterior insula, posterior superior temporal sulcus, and dorsolateral prefrontal cortex - underpins these effects. Moreover, although attention typically favors ingroup targets, outgroup members can be prioritized on occasion. The implications of this viewpoint and future lines of investigation are considered.

Contextual knowledge provided by a movie biases implicit perception of the protagonist

We are constantly categorizing other people as belonging to our in-group (‘one of us’) or out-group (‘one of them’). Such grouping occurs fast and automatically and can be based on others’ visible characteristics such as skin color or clothing style. Here we studied neural underpinnings of implicit social grouping not often visible on the face, male sexual orientation. A total of 14 homosexuals and 15 heterosexual males were scanned in functional magnetic resonance imaging while watching a movie about a homosexual man, whose face was also presented subliminally before (subjects did not know about the character’s sexual orientation) and after the movie. We discovered significantly stronger activation to the man’s face after seeing the movie in homosexual but not heterosexual subjects in medial prefrontal cortex, frontal pole, anterior cingulate cortex, right temporal parietal junction and bilateral superior frontal gyrus. In previous research, these brain areas have been connected to social perception, self-referential thinking, empathy, theory of mind and in-group perception. In line with previous studies showing biased perception of in-/out-group faces to be context dependent, our novel approach further demonstrates how complex contextual knowledge gained under naturalistic viewing can bias implicit social perception.

Effects of Baby Schema and Mere Exposure on Explicit and Implicit Face Processing

In an increasingly multicultural society, the way people perceive individuals from the same vs different ethnic groups greatly affects their own and societal well-being. Two psychological effects that influence these perceptions are the Mere-Exposure Effect (MRE), wherein familiarity with certain objects or persons suffices for people to develop a preference for them, and the Baby Schema (BS), a set of specific facial features that evokes caregiving behaviors and an affective orientation in adults. In the present study, we aimed to investigate whether these two effects play a role in implicit physiological responses to babies vs. adults faces belonging to participants in-group vs. out-group. In study 1, the pupillary diameter of 62 Caucasian participants (M = 31; F = 31) who observed adult and infant faces of different ethnic groups (Caucasian, Chinese) was measured. In study 2, brain waves of 38 Caucasian participants (M = 19; F = 19), who observed the same set of faces, were recorded using EEG. In both studies, adults explicit preferences (i.e., attitudes) toward faces were assessed using questionnaires. In Study 1, females showed greater attention to infant than adult faces (BS effect) in both pupils, regardless of the ethnic group of the face. By contrast, males attended to infant more than adult faces for out-group faces only (BS effect). In Study 2, greater left posterior-parietal alpha activation toward out-group compared to in-group adult faces was found in males (MRE). Participants with a low BS effect toward in-group baby faces exhibited greater left posterior alpha activation to out-group than in-group baby faces (MRE). These findings reveal how different levels of sensitivity to in-group infants may moderate perceptions of both in-group and out-group baby faces. Questionnaire measures on attitudes showed that males and females preferred in-group to out-group adult faces (MRE). Participants in Study 2 also reported a greater preference for infants than adults faces (BS effect). These findings explicate the roles of gender and the Baby Schema effect in moderating implicit processing of in-group and out-group faces, despite their lack in moderating explicit reports. Contradictory findings at the implicit (physiological) and explicit (self-report) levels suggest that differential processing of faces may occur at a non-conscious level.

Cultural Moderation of Unconscious Hedonic Responses to Food

Previous psychological studies have shown that images of food elicit hedonic responses, either consciously or unconsciously, and that participants' cultural experiences moderate conscious hedonic ratings of food. However, whether cultural factors moderate unconscious hedonic responses to food remains unknown. We investigated this issue in Polish and Japanese participants using the subliminal affective priming paradigm. Images of international fast food and domestic Japanese food were presented subliminally as prime stimuli. Participants rated their preferences for the subsequently presented target ideographs. Participants also rated their preferences for supraliminally presented food images. In the subliminal rating task, Polish participants showed higher preference ratings for fast food primes than for Japanese food primes, whereas Japanese participants showed comparable preference ratings across these two conditions. In the supraliminal rating task, both Polish and Japanese participants reported comparable preferences for fast and Japanese food stimuli. These results suggest that cultural experiences moderate unconscious hedonic responses to food, which may not be detected based on explicit ratings.

Paranoia and conspiracy: group cohesion increases harmful intent attribution in the Trust Game

Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about the cognitive mechanisms underpinning this conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-scale game theory approach (N > 1,000) to test whether the social cohesion of an opposing group affects paranoid attributions in a mixed online and lab-based sample. Participants spanning the full population distribution of paranoia played as proposers in a modified Trust Game: they were allocated a bonus and chose how much money to send to a pair of responders which was quadrupled before reaching these responders. Responders decided how much to return to the proposers through the same process. Participants played in one of two conditions: against a cohesive group who communicated and arrived at a joint decision, or a non-cohesive group who made independent decisions. After the exchange, proposers rated the extent to which the responders’ decisions were driven by (i) self-interest and (ii) intent to harm. Although the true motives are ambiguous, cohesive responders were reliably rated by participants as being more strongly motivated by intent to harm, indicating that group cohesion affects social threat perception. Highly paranoid participants attributed harmful intent more strongly overall but were equally reactive to social cohesion as other participants. This suggests that paranoia involves a generally lowered threshold for social threat detection but with an intact sensitivity for cohesion-related group characteristics.

Paranoia and conspiracy: group cohesion increases harmful intent attribution in the Trust Game

Current theories argue that hyper-sensitisation of social threat perception is central to paranoia. Affected people often also report misperceptions of group cohesion (conspiracy) but little is known about the cognitive mechanisms underpinning this conspiracy thinking in live interactions. In a pre-registered experimental study, we used a large-scale game theory approach (N > 1,000) to test whether the social cohesion of an opposing group affects paranoid attributions in a mixed online and lab-based sample. Participants spanning the full population distribution of paranoia played as proposers in a modified Trust Game: they were allocated a bonus and chose how much money to send to a pair of responders which was quadrupled before reaching these responders. Responders decided how much to return to the proposers through the same process. Participants played in one of two conditions: against a cohesive group who communicated and arrived at a joint decision, or a non-cohesive group who made independent decisions. After the exchange, proposers rated the extent to which the responders' decisions were driven by (i) self-interest and (ii) intent to harm. Although the true motives are ambiguous, cohesive responders were reliably rated by participants as being more strongly motivated by intent to harm, indicating that group cohesion affects social threat perception. Highly paranoid participants attributed harmful intent more strongly overall but were equally reactive to social cohesion as other participants. This suggests that paranoia involves a generally lowered threshold for social threat detection but with an intact sensitivity for cohesion-related group characteristics.

Neural Correlates of Group Bias During Natural Viewing

Individuals from different social groups interpret the world in different ways. This study explores the neural basis of these group differences using a paradigm that simulates natural viewing conditions. Our aim was to determine if group differences could be found in sensory regions involved in the perception of the world or were evident in higher-level regions that are important for the interpretation of sensory information. We measured brain responses from 2 groups of football supporters, while they watched a video of matches between their teams. The time-course of response was then compared between individuals supporting the same (within-group) or the different (between-group) team. We found high intersubject correlations in low-level and high-level regions of the visual brain. However, these regions of the brain did not show any group differences. Regions that showed higher correlations for individuals from the same group were found in a network of frontal and subcortical brain regions. The interplay between these regions suggests a range of cognitive processes from motor control to social cognition and reward are important in the establishment of social groups. These results suggest that group differences are primarily reflected in regions involved in the evaluation and interpretation of the sensory input.

Opening the "Black Box": Functions of the Frontal Lobes and Their Implications for Sociology

Previous research has provided theoretical frameworks for building inter-disciplinary bridges between sociology and the neurosciences; yet, more anatomically, or functionally focused perspectives offering detailed information to sociologists are largely missing from the literature. This manuscript addresses this gap by offering a comprehensive review of the functions of the frontal lobes, arguably the most important brain region involved in various "human" skills ranging from abstract thinking to language. The paper proposes that the functions of the frontal lobe sub-regions can be divided into three inter-related hierarchical systems with varying degrees of causal proximity in regulating human behavior and social connectedness: (a) the most proximate, voluntary, controlled behavior-including motor functions underlying action-perception and mirror neurons, (b) more abstract motivation and emotional regulation-such as Theory of Mind and empathy, and (c) the higher-order executive functioning-e.g., inhibition of racial bias. The paper offers insights from the social neuroscience literature on phenomena that lie at the core of social theory and research including moral cognition and behavior, and empathy and inter-group attitudes and provides future research questions for interdisciplinary research.

The racially diverse affective expression (RADIATE) face stimulus set

Faces are often used in psychological and neuroimaging research to assess perceptual and emotional processes. Most available stimulus sets, however, represent minimal diversity in both race and ethnicity, which may confound understanding of these processes in diverse/racially heterogeneous samples. Having a diverse stimulus set of faces and emotional expressions could mitigate these biases and may also be useful in research that specifically examines the effects of race and ethnicity on perceptual, emotional and social processes. The racially diverse affective expression (RADIATE) face stimulus set is designed to provide an open-access set of 1,721 facial expressions of Black, White, Hispanic and Asian adult models. Moreover, the diversity of this stimulus set reflects census data showing a change in demographics in the United States from a white majority to a nonwhite majority by 2020. Psychometric results are provided describing the initial validity and reliability of the stimuli based on judgments of the emotional expressions.

Insights From fMRI Studies Into Ingroup Bias

Intergroup biases can manifest themselves between a wide variety of different groups such as people from different races, nations, ethnicities, political or religious beliefs, opposing sport teams or even arbitrary groups. In this review we provide a neuroscientific overview of functional Magnetic Resonance Imaging (fMRI) studies that have revealed how group dynamics impact on various cognitive and emotional systems at different levels of information processing. We first describe how people can perceive the faces, words and actions of ingroup and outgroup members in a biased way. Second, we focus on how activity in brain areas involved in empathizing with the pain of others, such as the dorsal anterior cingulate cortex (dACC) and anterior insula (AI), are influenced by group membership. Third, we describe how group membership influences activity in brain areas involved in mentalizing such as the medial prefrontal cortex (mPFC) and temporoparietal junction (TPJ). Fourth, we discuss the involvement of the lateral orbitofrontal cortex (lOFC) in increased moral sensitivity for outgroup threats. Finally, we discuss how brain areas involved in the reward system such as the striatum and medial orbitofrontal cortex (mOFC), are more active when experiencing schadenfreude for outgroup harm and when rewarding ingroup (versus outgroup) members. The value of these neuroscientific insights to better understand ingroup bias are discussed, as well as limitations and future research directions.

Deflections from adolescent trajectories of antisocial behavior: contextual and neural moderators of antisocial behavior stability into emerging adulthood

BACKGROUND

Early adulthood is a critical period when young men involved in antisocial behavior (AB) may desist. Factors including marriage and employment have been shown to predict desistance, but little work has examined whether biological factors (e.g. neural reactivity) predict deflections from lifelong AB trajectories.

METHODS

We examined the continuity of, or desistance from, AB in early adulthood using group-based trajectories of AB across adolescence in a sample of 242 men from low-income, urban families. We examined contextual factors (romantic relationship quality, employment, neighborhood danger) and neural factors (amygdala reactivity to fearful faces, ventral striatum reactivity to reward) as moderators of the continuity of AB from adolescence (age 10-17) into early adulthood (age 22-23), and whether these pathways differed by race.

RESULTS

High relationship satisfaction and employment at age 20 predicted decreased AB at age 22-23, but only among men with adolescent-onset/moderate AB trajectories. Ventral striatum reactivity predicted continued AB, but only among African-American men with early-starting AB. Amygdala reactivity to fearful faces was related to later AB for those in the early-starting group, but in divergent directions depending on race: amygdala reactivity to fearful faces was positively related to AB in European-Americans and negatively related to AB among African-Americans.

CONCLUSIONS

Contextual factors only predicted deflections of AB in those engaged in late-starting, moderate levels of AB, whereas neural factors predicted continued AB only in those with early-starting, severe AB, and in divergent ways based on participant race. Though there is limited power to infer causality from this observational design, research on desistance broadly can contribute to informing personalized interventions for those engaged in serious adolescence AB.

Humans do not perceive conspecifics with a greater exposed sclera as more trustworthy: a preliminary cross-ethnic study of the function of the overexposed human sclera

Understanding the adaptive function of the unique morphology of the human eye, in particular its overexposed white sclera, may have profound implications for the fields of evolutionary behavioural science, and specifically the areas of human interaction and social cognition. Existing hypotheses, such as the cooperative eye hypothesis, have attracted a lot of attention but remain untested. Here, we: (i) analysed variation in the visible sclera size in humans from different ethnic backgrounds and (ii) examined whether intraspecific variation of exposed sclera size is related to trust. We used 596 facial photographs of men and women, assessed for perceived trustworthiness, from four different self-declared racial backgrounds. The size of the exposed sclera was measured as the ratio between the width of the exposed eyeball and the diameter of the iris (sclera size index, SSI). The SSI did not differ in the four examined races and was sexually monomorphic except for Whites, where males had a larger SSI than females. In general, the association between the SSI and trustworthiness was statistically insignificant. An inverted U-shaped link was found only in White women, yet the strength of the effect of interaction between sex and race was very small. Our results did not provide evidence for the link between exposed sclera size and trustworthiness. We conclude that further investigation is necessary in order to properly assess the hypotheses relating to the socially relevant functions of overexposed sclera.

Amygdala reactivity in ethnic minorities and its relationship to the social environment: an fMRI study

BACKGROUND

Ethnic minority individuals have an increased risk of developing a psychotic disorder, particularly if they live in areas of ethnic segregation, or low own group ethnic density. The neurobiological mechanisms underlying this ethnic minority associated risk are unknown. We used functional MRI to investigate neural responses to faces of different ethnicity, in individuals of black ethnicity, and a control group of white British ethnicity individuals.

METHODS

In total 20 individuals of black ethnicity, and 22 individuals of white British ethnicity underwent a 3T MRI scan while viewing faces of black and white ethnicity. Own group ethnic density was calculated from the 2011 census. Neighbourhood segregation was quantified using the Index of Dissimilarity method.

RESULTS

At the within-group level, both groups showed greater right amygdala activation to outgroup faces. Between groups, the black ethnicity group showed greater right amygdala activation to white faces, compared to the white ethnicity group. Within the black ethnicity group, individuals living in areas of lower own group ethnic density showed greater right amygdala reactivity to white faces (r = -0.61, p = 0.01).

CONCLUSIONS

This is the first time an increased amygdala response to white faces has been demonstrated in individuals of black ethnicity. In the black ethnicity group, correlations were observed between amygdala response and neighbourhood variables associated with increased psychosis risk. These results may have relevance for our understanding of the increased rates of paranoia and psychotic disorders in ethnic minority individuals.

Gene by Culture Effects on Emotional Processing of Social Cues among East Asians and European Americans

While Western cultures are more focused on individualization and self-expression, East Asian cultures promote interrelatedness. Largely unknown is how gene by culture interactions influence the degree to which individuals acquire culture, and the neurocircuitry underlying how social cues are processed. We sought to examine the interaction between DRD4 polymorphism and culture in the neural processing of social emotional cues. 19 Asian-born East Asian (AA) and 20 European American (EA) participants performed a shifted attention emotion appraisal functional magnetic resonance imaging (fMRI) task, which probes implicit emotional processing and regulation in response to social emotional cues. Half of the participants in each group were DRD4 2- or 7-repeat allele (2R/7R) carriers. AA participants showed larger left and right amygdala, and left hippocampal activation during implicit processing of fearful faces. There was a gene by culture interaction in the left insula during implicit processing of facial cues, while activation in EA DRD4 2R/7R carriers was larger than EA non-carriers and AA carriers. Our findings suggest that emotional facial cues are more salient to AA participants and elicit a larger amygdala reaction. Gene by culture interaction finding in insula suggests that DRD4 2R/7R carriers in each culture are more prone to adopting their cultural norm.

Group membership and racial bias modulate the temporal estimation of in-group/out-group body movements

Social group categorization has been mainly studied in relation to ownership manipulations involving highly-salient multisensory cues. Here, we propose a novel paradigm that can implicitly activate the embodiment process in the presence of group affiliation information, whilst participants complete a task irrelevant to social categorization. Ethnically White participants watched videos of White- and Black-skinned models writing a proverb. The writing was interrupted 7, 4 or 1 s before completion. Participants were tasked with estimating the residual duration following interruption. A video showing only hand kinematic traces acted as a control condition. Residual duration estimates for out-group and control videos were significantly lower than those for in-group videos only for the longest duration. Moreover, stronger implicit racial bias was negatively correlated to estimates of residual duration for out-group videos. The underestimation bias for the out-group condition might be mediated by implicit embodiment, affective and attentional processes, and finalized to a rapid out-group categorization.

Even subtle cultural differences affect face tuning

Culture shapes social cognition in many ways. Yet cultural impact on face tuning remains largely unclear. Here typically developing females and males from the French-speaking part of Switzerland were presented with a set of Arcimboldo-like Face-n-Food images composed of food ingredients and in different degree resembling a face. The outcome had been compared with previous findings obtained in young adults of the South-West Germany. In that study, males exhibit higher thresholds for face tuning on the Face-n-Food task than females. In Swiss participants, no gender differences exist in face tuning. Strikingly, males from the French-speaking part of Switzerland possess higher sensitivity to faces than their German peers, whereas no difference in face tuning occurs between females. The outcome indicates that even relatively subtle cultural differences as well as culture by gender interaction can modulate social cognition. Clarification of the nature of cultural impact on face tuning as well as social cognition at large is of substantial value for understanding a wide range of neuropsychiatric and neurodevelopmental conditions.