Racial Ingroup Bias and Efficiency Consideration Influence Distributive Decisions: A Dynamic Analysis of Time Domain and Time Frequency

Although previous studies have demonstrated that identity had effect on justice norms and behavioral decisions, the neural mechanism of that effect remains unclear. In this study, the subjects made their distributive decisions on the trade-off between equity and efficiency among Chinese and foreign children and their scalp potentials were recorded. Behavioral results showed that efficiency consideration played an important part in the distribution task. Meanwhile, participants gave preferential treatment to same-race children. Relative to the distribution within ingroup children, the distribution involving outgroup children induced higher N170 amplitude. The distribution involving outgroup children also elicited weakened P300 amplitude and enhanced delta response than the distribution within ingroup children when subjects are facing the conflict between equality and efficiency. In other words, ingroup bias affected the neural process of the trade-off between equality and efficiency. The combination of time-domain and time-frequency analyses provided spatiotemporal and spectral results for a better understanding of racial ingroup favoritism on distributive justice.

Turning the Face Inversion Effect on Its Head: Violated Expectations of Orientation, Lighting, and Gravity Enhance N170 Amplitudes

Face inversion effects occur for both behavioral and electrophysiological responses when people view faces. In EEG, inverted faces are often reported to evoke an enhanced amplitude and delayed latency of the N170 ERP. This response has been attributed to the indexing of specialized face processing mechanisms within the brain. However, inspection of the literature revealed that, although N170 is consistently delayed to a variety of face representations, only photographed faces invoke enhanced N170 amplitudes upon inversion. This suggests that the increased N170 amplitudes to inverted faces may have other origins than the inversion of the face's structure. We hypothesize that the unique N170 amplitude response to inverted photographed faces stems from multiple expectation violations, over and above structural inversion. For instance, rotating an image of a face upside–down not only violates the expectation that faces appear upright but also lifelong priors about illumination and gravity. We recorded EEG while participants viewed face stimuli (upright vs. inverted), where the faces were illuminated from above versus below, and where the models were photographed upright versus hanging upside–down. The N170 amplitudes were found to be modulated by a complex interaction between orientation, lighting, and gravity factors, with the amplitudes largest when faces consistently violated all three expectations. These results confirm our hypothesis that face inversion effects on N170 amplitudes are driven by a violation of the viewer's expectations across several parameters that characterize faces, rather than a disruption in the configurational disposition of its features.

Adaptation of The N170-Component of the Event-Related Brain Potential to Single Letters and Words in Adults and Children

Background. Neural specialization for print develops during learning to read and can be studied with event-related brain potentials (ERPs). Neural adaptation refers to smaller neural responses when a stimulus or a class of stimuli is repeated several times. Previously, neural specialization for print processing in adults has been shown to be reflected in the word-specific N170 component of the ERP. Furthermore, adapation of the N170 elicited by words has been found to correlate with reading speed. Here, we investigated adapation of the N170-component evoked by single letters, words and faces in seven to nine- year old German-language speaking children and in a group of adult normal readers. Results. For adults, we replicated previous reports of adaptation of N170-amplitude at posterior-temporal electrodes P7 and P8 for single letters and words. For children, we only observed adaptation of N170-amplitude for single letters. No adaptation of N170-amplitude was apparent for words. However, in both, children as well as adults, N170-adaptation did not correlate with measures of reading speed. For faces, that served as a non-linguistic control condition, no adaptation of N170 amplitude was observed. Conclusions. We conclude that adaptation of the word-specific N170 component of the ERP might be linked to increasing perceptual experience with letters and words.

Emotional Facial Expression Perception and Processing in AUD Subgroups

Deficits in emotion processing among individuals with AUD are well accepted, however the potential impact of polysubstance use in this population remains uninvestigated. The current work begins to fill this gap by analyzing affective perception and processing in community controls (CCs) and two AUD subgroups differentiated by presence (Alc-Drug) or absence (Alc-Only) of polysubstance use. Behavioral task performance and electroencephalographic (EEG) indices (N170, P3) were measured for an emotion judgement task where participants classified emotional facial expressions (EFEs) morphed to 65 or 95 percent intensity. Mixed model analyses detected deficits in emotion classification accuracy among Alc-Drug relative to other groups. Although there was a main effect of emotion (greater accuracy for positive vs. negative emotions), there was no group by emotion interaction. N170 amplitude analyses found only a main effect for emotion (greater amplitude for negative vs. positive emotions). P3 amplitude analyses detected differences between control and AUD individuals, but no difference between AUD subgroups. No correlation was found between accuracy and ERP amplitudes. These findings contribute to the developing literature on emotional processing deficits in AUD, including highlighting the importance of considering polysubstance use in characterizing these deficits.

Which Visual Modality Is Important When Judging the Naturalness of the Agent (Artificial Versus Human Intelligence) Providing Recommendations in the Symbolic Consumption Context?

This study aimed to explore how the type and visual modality of a recommendation agent’s identity affect male university students’ (1) self-reported responses to agent-recommended symbolic brand in evaluating the naturalness of virtual agents, human, or artificial intelligence (AI) and (2) early event-related potential (ERP) responses between text- and face-specific scalp locations. Twenty-seven participants (M = 25.26, SD = 5.35) whose consumption was more motivated by symbolic needs (vs. functional) were instructed to perform a visual task to evaluate the naturalness of the target stimuli. As hypothesized, the subjective evaluation showed that they had lower attitudes and perceived higher unnaturalness when the symbolic brand was recommended by AI (vs. human). Based on this self-report, two epochs were segmented for the ERP analysis: human-natural and AI-unnatural. As revealed by P100 amplitude modulation on visual modality of two agents, their evaluation relied more on face image rather than text. Furthermore, this tendency was consistently observed in that of N170 amplitude when the agent identity was defined as human. However, when the agent identity was defined as AI, reversed N170 modulation was observed, indicating that participants referred more to textual information than graphical information to assess the naturalness of the agent.

EPOC outside the shield: comparing the performance of a consumer-grade EEG device in shielded and unshielded environments

Low-cost, portable electroencephalographic (EEG) headsets have become commercially available in the last 10 years. One such system, Emotiv’s EPOC, has been modified to allow event-related potential (ERP) research. Because of these innovations, EEG research may become more widely available in non-traditional settings. Although the EPOC has previously been shown to provide data comparable to research-grade equipment and has been used in real-world settings, how EPOC performs without the electrical shielding used in research-grade laboratories is yet to be systematically tested. In the current article we address this gap in the literature by asking participants to perform a simple EEG experiment in shielded and unshielded contexts. The experiment was the observation of human versus wristwatch faces which were either inverted or noninverted. This method elicited the face-sensitive N170 ERP.In both shielded and unshielded contexts, the N170 amplitude was larger when participants viewed human faces and peaked later when a human face was inverted. More importantly, Bayesian analysis showed no difference in the N170 measured in the shielded and unshielded contexts. Further, the signal recorded in both contexts was highly correlated. The EPOC appears to reliably record EEG signals without a purpose-built electrically-shielded room or laboratory-grade preamplifier.

Time to Face Language: Embodied Mechanisms Underpin the Inception of Face-Related Meanings in the Human Brain

In construing meaning, the brain recruits multimodal (conceptual) systems and embodied (modality-specific) mechanisms. Yet, no consensus exists on how crucial the latter are for the inception of semantic distinctions. To address this issue, we combined electroencephalographic (EEG) and intracranial EEG (iEEG) to examine when nouns denoting facial body parts (FBPs) and nonFBPs are discriminated in face-processing and multimodal networks. First, FBP words increased N170 amplitude (a hallmark of early facial processing). Second, they triggered fast (~100 ms) activity boosts within the face-processing network, alongside later (~275 ms) effects in multimodal circuits. Third, iEEG recordings from face-processing hubs allowed decoding ~80% of items before 200 ms, while classification based on multimodal-network activity only surpassed ~70% after 250 ms. Finally, EEG and iEEG connectivity between both networks proved greater in early (0–200 ms) than later (200–400 ms) windows. Collectively, our findings indicate that, at least for some lexico-semantic categories, meaning is construed through fast reenactments of modality-specific experience.

Prejudice drives exogenous attention to outgroups

Exogenous attention allows the automatic detection of relevant stimuli and the reorientation of our current focus of attention towards them. Faces from an ethnic outgroup tend to capture exogenous attention to a greater extent than faces from an ethnic ingroup. We explored whether prejudice toward the outgroup, rather than lack of familiarity, is driving this effect. Participants (N = 76) performed a digit categorization task while distractor faces were presented. Faces belonged to (i) a prejudiced outgroup, (ii) a non-prejudiced outgroup and (iii) their ingroup. Half of the faces were previously habituated in order to increase their familiarity. Reaction times, accuracy and event-related potentials (ERPs) were recorded to index exogenous attention to distractor faces. Additionally, different indexes of explicit and implicit prejudice were measured, the latter being significantly greater towards prejudiced outgroup. N170 amplitude was greater to prejudiced outgroup—regardless of their habituation status—than to both non-prejudiced outgroup and ingroup faces and was associated with implicit prejudice measures. No effects were observed at the behavioral level. Our results show that implicit prejudice, rather than familiarity, is under the observed attention-related N170 effects and that this ERP component may be more sensitive to prejudice than behavioral measures under certain circumstances.

Altered P3a Modulations to Emotional Faces in Male Patients With Chronic Schizophrenia

Existing evidence suggests that patients with schizophrenia may have a deficit in processing facial expressions. However, the neural basis of this processing deficit remains unclear. A total of 20 men diagnosed with chronic schizophrenia and 13 age- and sex-matched controls participated in the study. We investigated visual N170 and P3a components evoked in response to fearful, happy, and sad faces during an emotion discrimination task. Compared with control subjects, patients showed significantly smaller N170 amplitudes bilaterally ( P = .04). We found no significant main effect of emotion of the presented faces (fearful, happy, or sad) on N170 amplitude. Patients showed significantly smaller P3a amplitudes in response to fearful ( P = .01) and happy ( P = .02) faces, but no significant between-group differences were observed for sad faces ( P = .22). Moreover, we found no significant P3a modulation effect in response to emotional faces in patients with schizophrenia. Our results suggest that altered P3a modulations to emotional faces may be associated with emotion recognition deficits in patients with schizophrenia.

Gender differences in subliminal affective face priming: A high-density ERP study

Background Subliminal affective priming effects (SAPEs) refer to the phenomenon by which the presentation of an affective prime stimulus influences the subsequent affective evaluation of a target stimulus. Previous studies have shown that behavioural performance is affected more by unconsciously processed stimuli than by consciously processed stimuli. However, the impact of SAPEs on the face-specific N170 component is unclear. In the current study, we investigated how subliminal processing of fearful faces affected the N170 for subsequent supraliminal target faces using event-related potentials (ERPs).Methods We used event-related potentials (ERPs) to study how SAEPs for fearful faces affect the N170 for subsequent supraliminal target faces. Japanese adults (n=51, 24 females) participated in this study. Subliminal prime faces (neutral or fearful) were presented for 17 ms, followed by a backward mask for 283 ms and target faces for 800 ms (neutral, emotionally ambiguous-fearful, or fearful). ERPs (128-ch) were recorded while participants judged the expression of target faces as neutral or fearful.Results Behavioral data revealed that participants judged target faces as more fearful in the fearful face prime condition compared with the neutral prime condition, regardless of emotional expression. Interestingly, we found gender-related differences in N170 amplitude; only female participants exhibited enhanced N170 amplitude for neutral faces primed by fearful faces. Therefore, a noticeable gender difference exists in the neural processing of subliminally perceived facial emotions.Conclusions Our ERP results suggest the existence of a gender difference in target-face processing preceded by subliminally presented face stimuli in the right occipito-temporal regions.