Influence of daily experiences on ERP correlates of face perception of ones' romantic partner
Romantic partners rely on key information from their partner's face to facilitate optimal social connections. Evidence suggests that the brain differentially responds to a partner's face as evidenced by event-related potentials (ERPs). Yet, little is known about how ERP responses are modulated by day-to-day biological or psychological shifts. In this study, we examined whether daily experiences related to feeling loved by ones' partner influenced brain responses. Twenty-eight adult romantic partners (20-40 years old) completed twice-daily surveys prior to completing a passive ERP face perception task. Amplitudes were larger to partner's face relative to celebrity (peak N250, mean P3) or stranger faces (mean P3). Greater mean level of feeling loved by partner was related to more negative N250 amplitudes and more positive P3 amplitudes across all conditions (partner, celebrity, and stranger faces). Persons with less variability in feeling loved by partner had more negative N250 amplitudes in response to their partner's face. These results suggest that daily experiences modulate neural markers of familiarity (N250, P3) and that less stability in feeling loved may influence facial identity retrieval for individuals giving the love.
Directed causal networks for leading and following in hyperscanning EEG
This explorative hyperscanning EEG whole-brain study describes activation networks within and between brains representing leading and following behavior. The directed information flow was analyzed for singles and pairs of brains simultaneously activated using the graph-based algorithm of PCMCI. This algorithm was previously tested for frontal activations in singles and pairs of brains, returning significant directed statistical dependencies. The participants led and followed each other using a minimal model based on rhythmic tapping. This whole-brain study resulted in directed causal connections representing neuronal networks for the social activities studied. The brain regions exhibiting the highest number of connections were chosen for further analysis from the extensive network of connections. This resulted in four networks representing within-brain and between-brains, respectively, for leading and following. Network commonalities aligned with previous research of leading and following reflecting cognition, working memory and social cognition, visual attention, and motoric engagement. Follower networks exhibited socially adaptive activations. The between-brain networks appear to involve more brain regions, possibly reflecting the more complex situation involving another person. The PCMCI could prove to be a suitable tool for identifying whole-brain networks of directed causality that represent leading and following, both within and between brains, using hyperscanning EEG data.
Dyad averaged BMI-dependent interbrain synchrony during continuous mutual prediction in social coordination
Obesity is linked to notable psychological risks, particularly in social interactions where individuals with high body mass index (BMI) often encounter stigmatization and difficulties in forming and maintaining social connections. Although awareness of these issues is growing, there is a lack of research on real-time, dynamic interactions involving dyads with various BMI levels. To address this gap, our study employed a joint finger-tapping task, where participant dyads engaged in coordinated activity while their brain activity was monitored using functional near-infrared spectroscopy (fNIRS). Our findings showed that both Bidirectional and Unidirectional Interaction conditions exhibited higher levels of behavioral and interbrain synchrony compared to the No Interaction condition. Notably, only in the Bidirectional Interaction condition, higher dyadic BMI was significantly correlated with poorer behavioral coordination and reduced interbrain synchrony. This finding suggests that the ability to maintain social coordination, particularly in scenarios requiring continuous mutual prediction and adjustment, is modulated by dyads' BMI.
Mothers with higher empathy have children who make moral decisions and exhibit higher medial prefrontal cortex (mPFC) activity when discussing hypothetical moral dilemmas: an fNIRS study from Singapore
Parents' empathic responses are crucial in shaping children's attitudes. Empathy triggers positive emotional responses, which facilitate adaptive moral judgment and utilitarian decisions. However, no study has examined the role of parental empathy in influencing children's moral reasoning and their underlying neural responses. In this study, we investigated the association between mothers' empathy levels and children's moral decisions and brain activity in the prefrontal cortex (PFC). 19 children wore a 20-channel functional Near-Infrared Spectroscopy (fNIRS) cap with a standard PFC montage while discussing preschool-aged stories with their mothers. We measured mothers' empathy levels using the Toronto Empathy Questionnaire and their preschool children's empathic tendencies by asking whether they would help the characters of these stories with simple chores in hypothetical scenarios. Findings showed that children are disposed to behave in ways parallel to their mother's attitudes. Empathic mothers have children who make prosocial decisions rooted in empathic mentalization. These helpful children also have higher activations in the medial prefrontal cortex (mPFC), the brain area associated with ethical decision-making. This study highlights the impact of parent-child communication in strengthening children's moral knowledge and moral emotions and emphasizes that parents' attitudes and interactions play a significant role in children's decision-making abilities.
The enhancement effect of social interaction on emotional contagion: an EEG-Based hyperscanning study
Emotional contagion refers to the tendency for individuals to replicate the emotional states of others primarily, within the context of social interactions. Prior research has focused on the real-time emotional contagion during interpersonal communication. However, this study proposes that social interaction experiences, particularly those involving cooperation, might also play a role in promoting emotional contagion. To investigate this issue, the present study divided participants into the interactive group and the control group and conducted EEG-based hyperscanning to explore the impact of interpersonal interaction experience on emotional contagion. Behavioral results indicated that individuals reported a greater psychological closeness to their partners after experiencing interaction. Additionally, the interactive group showed stronger emotional congruence between observers and senders. EEG results further demonstrated that inter-brain synchrony in the emotional contagion phase among the observer and sender of the interactive group was significantly higher than that of the control group and was significantly correlated with the observer's emotional state. This research suggests that social interaction experience may affect emotional contagion by altering the interpersonal dynamics. The present study adds to the understanding of how social interactions can shape emotional experiences and emphasizes that interpersonal experiences might be a key factor in promoting emotional contagion.
Why is the hyperscanning paradigm important for comparing the social brain across "digital" and "real-life" conditions? Introduction to special issue
The explosion of digital media has emerged quickly from the convergence of technological advances, pandemic urgency, and cultural changes that have now taken hold in the daily life of people around the world. With cell phone, tablet and laptop devices as well as broad internet service available to an estimated two-thirds of the world's population, the landscape of social interaction continues to change. "Social media" for personal, educational, business, health and other purposes is being used daily. With this shift, the field of social neuroscience has begun to consider both . The hyperscanning technique lends itself well to this challenge and is beginning to be applied to study of varied social constructs as well as clinical samples. This special issue has assembled a set of papers specifically focused on hyperscanning as an informative approach to investigating digital vs. in-person interactions. Papers present conceptual, methodological, and primary data findings. Authors address issues of interpersonal stress regulation, shared and distinctive bodily and physiological characteristics of digital vs. in-person experiences, the effects of prior social interaction on emotional contagion, and the possible influence of BMI on neural synchrony during motor coordination.
Neuroscientific protocols for the assessment and management of physiological responses to digital technostress
The digitalization process and the constant and prolonged use of digital technologies can lead to the development of digital stress, defined with the term technostress. This type of stress is related to the relationship between individuals and digital technologies and can lead to some related drifts, such as techno-anxiety and techno-addiction, concerning states of anxiety, apprehension, fear, or addiction toward digital technologies. Thus, it is crucial to avoid and lessen the potential development of technostress, particularly in the current historical age that has expanded the number of smart workers in constant touch with various digital technologies. This contribution highlights the potential applications of multi-integrated neuroscientific protocols to assess how technology can influence interpersonal dynamics and relational mechanisms, through the lenses of neuroassessment procedures; and to promote better emotional regulation and stress reduction through neuroempowerment protocols aimed at the reduction of technostress at the physiological level.
Comparing level 1 and level 2 visuo-spatial perspective-taking in the brain: evidence from fMRI
Level 1 visuo-spatial perspective-taking (VSPT) refers to judging what other people can and cannot see. Previous research has suggested that this form of VSPT can be achieved relatively effortlessly. Level 2 VSPT, which refers to judgments about how an object appears from different viewpoints, is conceptually more complex and linked to higher-level social cognition and mentalizing. Despite growing neuroscientific evidence on VSPT, fMRI studies have not yet directly compared levels of perspective-taking. Study 1 collected fMRI data from a within-subject comparison of level 2 versus level 1 VSPT. We used a common activation contrast comparing inconsistent versus consistent perspectives between self and others. In Study 2, we further distinguished the brain regions associated with level 2 VSPT from those responsive to stimulus ambiguity and complexity. To achieve this, we asked participants to adopt different viewpoints on ambiguous and unambiguous stimuli. Results from both studies found that brain activation for level 2 VSPT was particularly high in areas of the dorsal attention network. Follow-up connectivity analysis found that level 2 VSPT is primarily carried out by the dorsal attention and the frontoparietal network. These results align with theories suggesting that VSPT can be achieved by engaging visuospatial attention and inhibitory control processes.
Loneliness - not for the faint of heart? Effects of transient loneliness induction on neural and parasympathetic responses to affective stimuli
While loneliness has been associated with altered neural activity in social brain networks and reduced heart rate variability (HRV) in response to social stressors, it is still unclear whether these are related or parallel effects. Thus, the current study aimed to examine the relationship between loneliness and neural and parasympathetic responses to social stimuli by using an experimental induction of momentary loneliness. Sixty-three participants (18-35 y.o.) received manipulated feedback about their future relationships to induce either loneliness (Future Alone, FA; = 31) or feelings of belonging (Future Belong, FB, = 32) and completed a functional magnetic resonance imaging session with concomitant HRV measurement during which affective pictures with social or nonsocial content were presented. In line with our previous research, decreased vagal flexibility and more negative affect were observed in participants subjected to the loneliness induction. Furthermore, even though no significant between-group differences in neural activity were observed, the neural response to negative social vs nonsocial stimuli in the temporoparietal junction was positively associated with the parasympathetic response, and this relationship was stronger in the FA group. Taken together, these results suggest that transient feelings of loneliness may disrupt adaptive responding to environmental demands and negatively impact brain-heart interactions.
The impact of stigma on quality of life in patients with epilepsy
Epilepsy is one of the chronic neurological diseases with high stigmatization due to the psychosocial problems caused by seizures. The study was conducted to examine the quality of life and stigma in people with epilepsy (PWE).
Oxytocin and vasopressin 1a receptor alterations in the superior temporal sulcus and hypothalamus in schizophrenia
Schizophrenia is a severe psychiatric condition marked by social impairments. Given that social cognitive functioning strongly predicts life outcomes in schizophrenia, understanding its neurobiological basis is crucial. This study used receptor autoradiography to measure vasopressin 1a (AVPR1a) and oxytocin receptor (OXTR) densities in postmortem brain tissue from individuals with schizophrenia ( = 23) and matched controls ( = 18). We focused on the superior temporal sulcus, a region involved in social perception and often impaired in schizophrenia. AVPR1a binding densities exceeded those of OXTR. Notably, AVPR1a densities increased with age in females with schizophrenia, which may explain age-related changes in positive symptom severity (e.g. paranoia) in this group. Additionally, schizophrenia was associated with increased OXTR and a trend toward higher AVPR1a densities in the hypothalamus, a region central to oxytocin and vasopressin synthesis and stress response regulation. These findings suggest compensatory upregulation of nonapeptide receptor systems due to potentially reduced oxytocin and vasopressin release. Overall, our results highlight age- and sex-dependent alterations in receptor binding, providing insights into the neurobiology of social dysfunction in schizophrenia.
An ERP-study on the extent to which partisanship conditions the early processing of politicians' faces
Partisanship has been associated with various cognitive biases. These findings are primarily based on self-reports and task performance and less on measures of neural activity. We reviewed the literature on in-group vs. out-group bias that employs face-viewing paradigms and ERP methodology to investigate unconscious bias in politics. We subsequently preregistered hypotheses about the extent to which partisanship is associated with early neural processing of political leaders' faces. Our lab experiment was conducted in the Netherlands ( = 51), a multi-party democracy, and sufficiently powered to pick up modest effect sizes for in-party vs. out-party comparisons. As expected, we find that politicians' faces elicit a stronger N170 ERP response than strangers' faces, but we did not find the same pattern for the N250 component. Contrary to our hypotheses, we did not find statistically significant differences in the P200 and N200 components for the in-party vs. out-party comparison. These findings, supported by our cluster-based permutation analysis, indicate that seeing faces of political leaders enhances attention during facial processing, regardless of party affiliation, possibly due to their frequent and affectively salient presence in media. Since in-party vs. out-party differences did not emerge early on, implications for partisanship are discussed relative to racial and minimal group bias findings.
Non-significant results as for the association between heart rate variability, personality, and the objectification of lab-animals into the conduct of animal testing
To develop pharmaceutical drugs, people experiment on lab-animals. While this practice disturbs the general population, various factors in laboratory settings may contribute to enabling experiments that harm animals. Using an ultra-realistic protocol mimicking animal research and collecting behavioral and physiological data, we invited laypersons from the general population to administrate a toxic drug on a (fake) laboratory animal. This preregistered study ( = 145) aimed to examine individual determinants and contextual frameworks that may influence willingness to engage in such experimentation. Because low self-regulatory abilities are associated with less discomfort seeing others suffer, and that objectification of lab-animals allows disengagement from them, we also examined whether they both would predict involvement in an animal-research. We also examined whether some personality markers known to predict human-animal relations (i.e. social dominance orientation, speciesist attitudes, and empathic dispositions) could be related to the willingness to experiment on a lab animal. Overall, the results of this research were mixed, as neither self-regulation abilities, animal objectification, social dominance orientation, nor empathy significantly predicted participation in animal testing. However, low speciesist attitudes significantly reduced the willingness to kill animals for science.
A neuroimaging-based meta-analysis of prosocial behavior in childhood and adolescence
Despite increasing interest in the neural underpinnings of prosociality during childhood and adolescence, there is little convergence across studies of brain activations associated with prosocial behavior in developmental populations. Here, we build on 11 neuroimaging studies on prosocial behavior in developmental samples of average age between 8 and 17 years and conducted an Activation Likelihood Estimation meta-analysis. We found clusters of significant spatial convergence across studies in the insulae, inferior frontal gyrus, middle cingulum, and the precentral gyrus. The cluster in the cingulate cortex, which existing literature associates with cognitive control, shows overlap with previous meta-analytical data on prosocial behavior in adults. This region may constitute a core neurocognitive mechanism underlying prosociality from childhood to adulthood.
Social status in zebrafish modulates the behavioral response to 5-HT2C receptor agonists and antagonists
The effects of previous social experiences on social behavior have been demonstrated across species both in cooperative and competitive contexts. In dominance-subordinate hierarchies, differences across social ranks have been observed in many different mechanisms. Dominance hierarchies interfere in defensive behavior, where subordinate animals present a greater defensive behavior, regarding potential threats ("anxiety-like behavior"), than dominant animals. The serotonergic system plays a key role in regulating and mediating threat responses, including 5-HT2 receptors in the types of proximal threat responses modulated by the stress of social defeat. We separated 148 adult zebrafish in pairs and allowed them to interact for five days; after that, the dominant-subordinate rank was determined, and animals were treated with a 5-HT receptor agonist (MK-212) or antagonist (RS-102221) before being observed in the novel tank test. While MK-212 increased bottom-dwelling, erratic swimming, and freezing across all statuses, RS-102221 decreased these variables in dominants but increased them in subordinates. Moreover, the effects of MK-212 were larger in subordinates than in controls or dominants, suggesting a sensitization of the 5-HT receptor.
Recognizing communicative intentions from single- and dyadic point light displays in autistic adults
The present study compares the ability of non-autistic (NA) and autistic adults (ASD) with intellectual functioning in the normal range to process communicative intentions from biological motion (BM) - a capacity often considered as a prerequisite for a higher-order social cognition (SC). Twenty-nine ASD and 29 NA completed two tasks assessing the ability to recognize the communicative cues presented by either one or two point-light agents, as well as one point-light emotion recognition task and additional measures of SC abilities. Autistic participants demonstrated a decreased ability to recognize communicative intentions from BM ( = 0.02 for dyadic and = 0.03 for single agent task) despite similar levels of neurocognitive and social cognitive functioning. Additional exploratory analyses revealed an indirect trajectory linking the capacity to recognize communication from BM with autism symptoms through social cognitive capacity. Autistic adults may experience difficulties in processing communicative intentions, even in the absence of detectable higher-order SC problems. A possible mechanism might be the engagement in compensatory strategies that are inadequate for detecting lower-order intuitive social cues. Therefore, including tasks that assess the ability to detect communicative cues from BM may be beneficial for autistic adults with high cognitive abilities, in whom SC difficulties might be overlooked.
The influence of empathic concern on evaluative processing in self and charity outcomes
Empathy plays a crucial role in determining how one understands others' emotional experiences and behavioral decisions. This study aimed to explore whether empathic concern affects the processing of self-related and charity-related outcome evaluations. In this study, participants performed gambling tasks for themselves and low- and high-empathy charities. The behavioral results showed that low-empathy charities had a significantly higher risk rate than the self, whereas there was no significant difference between low-and high-empathy charities. The event-related potential (ERP) results showed that the P300 valence difference (d-P300) of the self was significantly higher for high-empathy charitable activities than for low-empathy charitable activities, and the d-P300 of high-empathy charitable activities was significantly higher than that of low-empathy charitable activities. The P300 valence differences primarily originated from activation difference in the posterior mid-cingulate cortex (pMCC) and medial prefrontal cortex (mPFC). The time-frequency analysis showed that positive outcomes induced greater β2 event-related desynchronization (ERD) amplitudes for high-empathy charitable activities compared to negative outcomes. These findings suggest that empathic concern increased the distinction between good and bad outcomes for charities and promoted greater cognitive effort allocation toward prosocial rewards. The d-P300 is closely linked to activations in the pMCC and mPFC.
Social group size alters social behavior and dopaminergic and serotonergic systems
Social behavior is affected by social structure type, but how neural function changes with social type remains unclear. We investigated whether social group size affects social behaviors based on dopamine (DA) and serotonin (5-HT) systems. Four-week-old male mice were housed under different social group sizes: one, two, four, and eight mice per cage (1mpc, 2mpc, 4mpc, 8mpc, respectively). After 4 weeks, social preference, social interaction, and forced swim tests were performed to test sociability and anxiety, respectively, followed by analysis of DA and 5-HT and their metabolites (3,4-dihydroxyphenylacetic acid [DOPAC], 3-methoxytyramine [3-MT], norepinephrine, and 5-hydroxyindoleacetic acid [5-HIAA]). Social interactions and anxious behavior decreased with increased social group size. DA, 3-MT, and 5-HT levels decreased with increasing social group size, whereas DOPAC and 5-HIAA levels increased in the extended mesocorticolimbic system, including the dorsal striatum. Moreover, the increased social group size resulted in increased DOPAC/DA and 5-HIAA/5-HT ratios, accompanied by a decrease in the 3-MT/DA ratio within the extended mesocorticolimbic system. Linear regression analysis also revealed that social group size affects DA and 5-HT turnover. These suggest that social group size may influence behavior and monoamine levels, potentially contributing to DA- and 5-HT-related psychiatric disorders.
Executive functions in adolescence: A longitudinal study comparing evaluations before and after the COVID-19 pandemic
The change in the educational model derived from the COVID-19 pandemic might have an impact on cognitive development, particularly on Executive Functions (EFs). The aim of this study was to explore cognitive performance in adolescents at two time points (12 and 14 years of age), before and after the pandemic restrictions. We also analyzed possible sex differences in the results. We evaluated EFs using the Neuropsychological Battery of Executive Functions and Frontal Lobes (BANFE-2), which includes four cognitive indices corresponding to specific cognitive functions and associated prefrontal areas: Orbitofrontal Cortex (OC index -OCI-), Anterior Prefrontal Cortex (APCI), Dorsolateral Prefrontal Cortex (DCI), and Prefrontal cortex as an index of global EFs (EFI). The ANOVA conducted to compare the evaluations before and after the pandemic revealed no significant pre-post-pandemic differences in any sex and in any BANFE-2 index, except for the OCI, in which post-pandemic performance was impaired in boys (pre and post mean score = 96.61 vs. 66.53), but not in girls (pre and post mean score = 93.55 vs. 95.0). Our findings are thus compatible with the idea of a different vulnerability to change in the educational model between sexes, and they also reveal which specific EFs may have been affected during the pandemic.
Hemispheric alpha asymmetry differentiates within-participants social power states: high social power increases and low social power decreases left frontal cortical activity
Social power is linked to approach and withdrawal motivational systems, with frontal alpha asymmetry (FAA) in the electroencephalogram (EEG) potentially reflecting these tendencies. Higher left-frontal activity suggests approach, while lower levels indicate withdrawal. In this study, we used a novel within-subject design to explore how social power affects FAA. Twenty-five participants completed an episodic recall task inducing high or low social power, or a neutral condition, in random order. EEG alpha power (8-12 hz) was measured to calculate FAA indices for frontal and parietal-occipital regions and compared to resting-state asymmetry. Results showed a significant increase in left-hemispheric activity during high social power recall, affecting both frontal and non-frontal regions, compared to low power and control conditions. Low social power was associated with the least left hemispheric activity. These findings highlight strong effects of social power on brain systems related to approach and avoidance but challenge the notion that FAA is confined to frontal regions. The study enhances understanding of the neural mechanisms behind social power and underscores the value of within-subject designs and baseline measurements in studying neural activity related alpha asymmetry and social power.
The role of the medial prefrontal cortex (mPFC) in social decision-making against high- and low-rank opponents: a transcranial direct current stimulation (tDCS) study
Social hierarchy is a key determinant of behavior and individuals interact with others based on their social rank. Previous research has emphasized the role of the mPFC in learning social hierarchies. This study employed a social rank learning task alongside a modified version of the Ultimatum Game (UG) to investigate how individuals respond to monetary offers from different social ranks and whether the mPFC modulates these reactions. Our findings indicate that unfair offers are more likely to be rejected and offers made by individuals of lower social rank are more likely to be rejected compared to those from higher social rank. Additionally, men tend to respond quicker than women in the UG. Remarkably, participants who received tDCS over the mPFC demonstrated higher rejection rates and faster response times for offers of low-rank individuals, while the lower rejection rates and slower responses to offers from high-rank opponents. These results shed light on the neural mechanisms involved in social decision-making in competitive contexts. In particular, they reveal increased sensitivity of the mPFC to social ranks after electrical stimulation, which might be an evidence for its role in shaping decisions and reactions toward unfairness within the existing social hierarchies.
How does teaching experience impact brain processes underlying the theory of mind? Study on primary school educators
Despite its importance for daily social interactions, few studies have explored interindividual differences in the Theory of Mind (ToM) abilities of healthy adults. We used Children's False-Attribution (CFA), Children's False-Beliefs (CFB), and Belief-Desire Reasoning tasks, along with fMRI-based assessments, in a comparative analysis of ToM among primary school teachers (PST; = 27), skilled in social interactions with children, and matched controls (MC; = 24), who lacked such experience. PST demonstrated slower reaction times than MC in Adult and Child false-belief stories of CFB. However, no other behavioral differences between the groups and between-group differences were observed at the brain level. Both groups presented similar valence ratings for stories in the CFA. Notably, fMRI analysis revealed a group-by-condition interaction effect in the right lateral orbitofrontal cortex (OFC). In PSTs, OFC activation decreased during negative false-attribution stories regarding children compared to stories related to adults, whereas MC demonstrated an opposite activation pattern. Between-group differences in right lateral OFC activity possibly signify a neural efficiency effect secondary to frequent social interactions of PSTs, unlike the MCs, with children in the working environment. These results underscore the significance of everyday social experiences in the functional plasticity of ToM networks.
Pair bond quality influences social conditioned place preference expression, passive coping behavior, and central oxytocin receptor expression following partner loss in male prairie voles
The dissolving of social bonds is disruptive and leads to increased stress responsivity and a strong desire for reunion. The oxytocin (OXT) system is critical for the formation of social attachments, such as pair bonds, and is also involved in social recognition, social memory, and social vigilance. Therefore, long-term changes in the OXT system resulting from cohabitation and pair bonding may contribute to reunion-seeking behavior. Here, we employed social conditioned place preference (SCPP) and the forced swim test (FST) to examine sensitivity to partner-associated contexts and passive stress coping following a period of partner separation. We found that opposite-sex cohabitation led to SCPP formation only in male prairie voles with a strong preference for their partner, and this SCPP was maintained following short-term loss of a pair bonded partner. Furthermore, pair bonded males that were separated from their partner displayed more passive stress-coping than those that were not bonded to their lost partner, suggesting that differences in prairie vole mating tactics (i.e. formation of a bond or not) influence the behavioral response to partner separation. Finally, we found changes in OXTR binding that may reflect variation in loss-related behavioral phenotypes based on different mating strategies.
The impact of social isolation on depression-like behavior in carioca high- and low-conditioned freezing rats
This study investigated the impact of social isolation in Carioca High-Conditioned Freezing (CHF) rats, an animal model of generalized anxiety disorder (GAD). Animals selected for high (CHF), low trait anxiety (Carioca Low-Conditioned Freezing, CLF), and control rats from randomly bred populations (CTL) were housed in groups or kept isolated in their cages for 14 consecutive days. On the fifteenth day, all animals underwent the Forced Swimming Test (FST), where the latency to immobility was assessed as a depressive-like measure. Under standard grouping conditions, CHF rats showed a shorter latency to immobility in the FST compared to CTL and CLF animals, indicating depressive-like characteristics and possible GAD comorbidity. Social isolation decreased the latency to immobility in CLF and CTL animals, while it paradoxically increased this measure in CHF animals. Therefore, social isolation exerted a depressive-like action in CTL and CLF rats, but had a protective or "antidepressant-like" effect in CHF animals. Since, CHF rats are housed with other animals with high trait anxiety, such protective action induced by social isolation might have been due to the mitigation of what has been referred to as "social stress contagion". These results are discussed regarding the association between depressive-like behaviors and reduced social engagement.
Social and perceptual decisions predict differences in face inversion neural correlates: Implications for development and face perception methods
Social attention, an important mechanism that orients people to social cues, is critical for the development of higher-ordered features of social cognition. Both endogenous (i.e. automatic and undirected) and exogenous (i.e. purposeful and directed) social attention is important for processing social features, yet there is limited work systematically addressing how different experimental manipulations modulate social attention. This study examined how endogenous and exogenous manipulations of a classic face inversion task influence ERP activity in adults ( = 71) and adolescent youth ( = 65). Results from Study 1 indicated a lack of task differences for P1 and N170 but a larger inversion effect for P3 when a social perceptual decision was required. Study 2 demonstrated developmental differences in the youth, such that youth and adults had opposite inversion effects for N170 and youth had no effect for the P3. These findings indicate that face perception neural markers are sensitive to exogenous decisions, with development still active in adolescence. This is important to consider when designing future studies, as task-based decisions may alter the neural responses to faces differentially by age.
Exploring how first- and third-person narrative modulates neural activation during a social cognition task. An event-related potentials (ERPs) study
Several studies showed a positive effect of stories on Theory of Mind (ToM) performance. The aim of the present exploratory study was to investigate whether and how a specific aspect of narrative, i.e., character perspective, modulates the brain activation in response to a ToM task and improve the accuracy. Fifty participants were divided in three groups based on the text assigned: first-person perspective group (1 G; = 16), third-person perspective group (3 G; = 18) and a scientific essay group (EG; = 16). The electroencephalographic and behavioral responses to eyes expressions, taken from the "Reading the Mind in the Eyes" test, were recorded pre-(T0) and post-(T1) reading task. The main results showed a greater N100 on left fronto-central electrodes and a greater P220-400 on right temporo-parietal electrodes in response to eye expressions at T1 compared to T0 in 3 G. A lower N220-400 was found on right fronto-central in response to eye expressions at T1 compared to T0 in 1 G and 3 G. The results suggest that, although reading first- and third-person stories modulates self-processes in a similar way, third-person stories involve an early stage of processing and a more extended neural network including anterior-posterior brain sites.
Volition as a modulator of the intergroup empathy bias
Neural reactions to others' pain are usually lower when the individual is of a different ethnicity than when they are of the same ethnicity. This suggests that empathy is not only an automatic phenomenon but also a motivated one. In the present study, we tested whether one's willingness to increase or decrease empathy would correspondingly increase or decrease the neural empathic response, as measured with electroencephalography (EEG), irrespective of ethnicity. In Study 1, participants were presented with pictures displaying painful or non-painful stimulations on an individual from a similar or different ethnic group. In Study 2, the procedure was relatively similar but employed a within-subject design and was conducted in two countries: Belgium and Rwanda. Overall, EEG results showed that participants successfully increased their neural response to the pain of others, irrespective of the others' ethnicity in Study 1. However, the within-subject design used in Study 2 revealed additional nuances, as we observed that participants increased their neural pain response selectively toward ingroup individuals. Our findings indicate that observing the pain of a single person, regardless of ethnicity, can heighten one's neural reaction. Yet, when both ingroup and outgroup members are present, the neural response intensifies only for ingroup members.
An EEG hyperscanning study during persuasion toward groupness. The frontal brain area activation as a function of role
This hyperscanning study explored the electrophysiological (EEG) patterns of dyads during a naturalistic persuasive interaction, in which the persuader had to convince the receiver that choosing a group solution was the most effective way to solve a group hypothetical everyday situation. Fifteen dyads composed of a persuader and a receiver were involved in a persuasive interaction while EEG data were recorded. EEG frequency bands (delta, theta, alpha, beta and gamma bands) were analyzed, first, considering the distinct role of the participants and, second, dividing the dyads according to the perceived effectiveness of persuasion. The intra-brain results showed greater activation of the delta, theta and alpha bands in the frontal area of the persuader compared to the receiver. The inter-brain analyses reported a significantly increased dissimilarity activation for delta and theta band in the frontal area compared to more temporo-central and parieto-occipital regions, regardless of the perceived effectiveness of persuasion. To summarize, the process of enhancing groupness during a persuasive interaction generates in the persuader a specific EEG pattern involving mainly low frequency bands activation in the frontal brain regions, suggesting a significant attentional effort and emotional involvement.
Readiness potentials changed by decision-making in the chicken game
The chicken game, a well-established social dilemma paradigm, is widely used to study cooperative and competitive behaviors. Strategic decision-making in this game is influenced by the outcomes of cooperative and competitive interactions, with feedback-related event-related potentials (ERPs) during the feedback phase being a primary research focus. However, it remains unclear whether specific ERP components associated with strategic decision-making are present during the response phase. This study implemented a computerized chicken game featuring two cars - one representing the participant and the other the opponent - driving toward each other. Players chose to "give way" or "go straight," with the opponent's decisions controlled by a computer under high-cooperation (70% "give way") and low-cooperation (30% "give way") conditions. Participants made their choices via key presses, and outcomes were presented during the feedback phase. Results revealed a readiness potential (RP) during the response phase, with increased RP amplitudes observed when participants could not accurately predict the opponent's choice, regardless of cooperation condition. These findings suggest that the RP component reflects strategic adjustments and decision-making processes in social dilemmas, providing a potential ERP marker for such contexts.
