Examining the value of body gestures in social reward contexts

Frontal alpha asymmetry predicts subsequent social decision-making: A dynamic multilevel, neural, and developmental perspective

Social motivation, the human desire to engage with others, is likely to underlie higher levels of social cognition and the formation of interpersonal relationships. Yet, this topic has been understudied in adolescents despite the critical developmental and maturational changes that occur during this period and the relevance of social motivation to clinical and neurodevelopmental disorders. Using electroencephalography (EEG) and an implicit-association paradigm (Choose-A-Movie Task; Dubey et al., 2015), we examined how brain responses underlying socially motivated decisions informed future decisions in 54 youth (aged 10-14 years) and 50 young adults (aged 18-33 years). As the first study to use this task during EEG recording, we implemented time-frequency analyses and a trial-by-trial dynamic statistical approach. Results suggested that both age groups preferred low-effort choices and increasingly preferred nonsocial choices over time. P3 amplitude also increased over time and was sensitive to effortful decisions, particularly for adults, but not social content. Both groups showed larger leftward frontal alpha asymmetry (FAA) during nonsocial feedback, and FAA predicted future decisions differently for adults than youth. The current study highlights FAA and trial-by-trial analyses as useful tools in understanding the neural mechanisms underlying socially motivated decisions, which differ across development, time, and individuals.

The priming effect of emotional words on body expressions: Two ERP studies

The impact of emotional words on the recognition of body expression and the underlying neurodynamic mechanisms remain poorly understood. This study used a classic supraliminal priming paradigm and event related potential (ERP) to investigate the effect of emotion-label words (experiment 1) and emotional verbs (experiment 2) on the recognition of body expressions. The behavioral results revealed that individuals exhibited a higher accuracy in recognizing happy expressions when presented with a happy-label word condition, in contrast to neutral expressions. Furthermore, it was observed that the accuracy of recognizing happy body expressions was reduced when preceded by angry verb priming, compared to happy and neutral priming conditions. Conversely, the accuracy of recognizing angry body expressions was higher in response to angry verb priming than happy and neutral primings. The ERP results showed that, in the recognition of happy body expressions, the P300 amplitude elicited by angry-label words was more positive, while a congruent verb-expression condition elicited more positive P300 amplitude than an incongruent condition in the left hemisphere and midline. However, in the recognition of angry body expressions, the N400 amplitude elicited by a congruent verb-expression condition was smaller than that elicited by an incongruent condition. These results suggest that both abstract emotion-label words and specific emotional verbs influence the recognition of body expressions. In addition, integrating happy semantic context and body expression might occur at the P300 stage, whereas integrating angry semantic context and body expression might occur at the N400 stage. These findings present novel evidence regarding the criticality of emotional context in the recognition of emotions.

Multi-view emotional expressions dataset using 2D pose estimation

Human body expressions convey emotional shifts and intentions of action and, in some cases, are even more effective than other emotion models. Despite many datasets of body expressions incorporating motion capture available, there is a lack of more widely distributed datasets regarding naturalized body expressions based on the 2D video. In this paper, therefore, we report the multi-view emotional expressions dataset (MEED) using 2D pose estimation. Twenty-two actors presented six emotional (anger, disgust, fear, happiness, sadness, surprise) and neutral body movements from three viewpoints (left, front, right). A total of 4102 videos were captured. The MEED consists of the corresponding pose estimation results (i.e., 397,809 PNG files and 397,809 JSON files). The size of MEED exceeds 150 GB. We believe this dataset will benefit the research in various fields, including affective computing, human-computer interaction, social neuroscience, and psychiatry.

Effects of positive and negative social feedback on motivation, evaluative learning, and socio-emotional processing

Social rewards and punishments are strong motivators. Since experimental work has focused on young adults using simplistic feedback, the effects of more naturalistic stimuli on motivation, evaluative learning, and socio-emotional processing with advanced age remain unclear. Therefore, we compared the effects of static (photos) vs dynamic (videos) social feedback in a social incentive delay (SID) task in young (18-35 years) and older adults (50-84 years) with neutral, positive, and negative feedback, on response times (RTs), and assessed the emotional valence of feedback cues and feedback videos. We found that anticipating positive and negative social feedback accelerated RTs regardless of age and without additional effects of video feedback. Furthermore, the results suggest a valence transfer from positive feedback videos to predictive cues in both groups (i.e., evaluative learning). Finally, older adults reported less pronounced negative affect for negative feedback videos, indicating age differences in socio-emotional processing. As such, our findings foster our understanding of the underlying cognitive and emotional aspects involved in the processing of social rewards and punishments.

Construction and validation of the Dalian emotional movement open-source set (DEMOS)

Human body movements are important for emotion recognition and social communication and have received extensive attention from researchers. In this field, emotional biological motion stimuli, as depicted by point-light displays, are widely used. However, the number of stimuli in the existing material library is small, and there is a lack of standardized indicators, which subsequently limits experimental design and conduction. Therefore, based on our prior kinematic dataset, we constructed the Dalian Emotional Movement Open-source Set (DEMOS) using computational modeling. The DEMOS has three views (i.e., frontal 0°, left 45°, and left 90°) and in total comprises 2664 high-quality videos of emotional biological motion, each displaying happiness, sadness, anger, fear, disgust, and neutral. All stimuli were validated in terms of recognition accuracy, emotional intensity, and subjective movement. The objective movement for each expression was also calculated. The DEMOS can be downloaded for free from https://osf.io/83fst/ . To our knowledge, this is the largest multi-view emotional biological motion set based on the whole body. The DEMOS can be applied in many fields, including affective computing, social cognition, and psychiatry.

Anticipating social feedback involves basal forebrain and mesolimbic functional connectivity

The mesolimbic system and basal forebrain (BF) are implicated in processing rewards and punishment, but their interplay and functional properties of subregions with respect to future social outcomes remain unclear. Therefore, this study investigated regional responses and interregional functional connectivity of the lateral (l), medial (m), and ventral (v) Substantia Nigra (SN), Nucleus Accumbens (NAcc), Nucleus basalis of Meynert (NBM), and Medial Septum/Diagonal Band (MS/DB) during reward and punishment anticipation in a social incentive delay task with neutral, positive, and negative feedback using high-resolution fMRI (1.5mm³). Neuroimaging data (n=36 healthy humans) of the anticipation phase was analyzed using mass-univariate, functional connectivity, and multivariate-pattern analysis. As expected, participants responded faster when anticipating positive and negative compared to neutral social feedback. At the neural level, anticipating social information engaged valence-related and valence-unrelated functional connectivity patterns involving the BF and mesolimbic areas. Precisely, valence-related connectivity between the lSN and NBM was associated with anticipating neutral social feedback, while connectivity between the vSN and NBM was associated with anticipating positive social feedback. A more complex pattern was observed for anticipating negative social feedback, including connectivity between the lSN and MS/DB, lSN and NAcc, as well as mSN and NAcc. To conclude, behavioral responses are modulated by the possibility to obtain positive and avoid negative social feedback. The neural processing of feedback anticipation relies on functional connectivity patterns between the BF and mesolimbic areas associated with the emotional valence of the social information. As such, our findings give novel insights into the underlying neural processes of social information processing.

A neurobiological perspective on social influence: Serotonin and social adaptation

Humans are inherently social beings. Being suggestible to each other's expectations enables pro-social skills that are crucial for social learning and adaptation. Despite its high relevance for psychiatry, the neurobiological mechanisms underlying social adaptation are still not well understood. This review therefore provides a conceptual framework covering various distinct mechanisms underlying social adaptation and explores the neuropharmacology - in particular the role of the serotonin (5-HT) system - modulating these mechanisms. This article therefore reviews empirical results on social influence processing and reconciles them with recent findings from psychedelic research on social processing to elucidate neurobiological and neuropharmacological underpinnings of social adaptation. Various computational, neurobiological, and neurochemical processes are involved in distinct mechanisms underlying social adaptation such as the multisensory process of social information integration that is crucial for the forming of self-representation and representations of social norms. This is again associated with self- and other-perception during social interactions as well as value-based decision making that guides our behaviour in daily interactions. We highlight the critical role of 5-HT in these processes and suggest that 5-HT can facilitate social learning and may represent an important target for treating psychiatric disorders characterized by impairments in social functioning. This framework also has important implications for psychedelic-assisted therapy as well as for the development of novel treatment approaches and future research directions.