Communication and Imitation

Competition is a common occurrence in life, but the influence of intimate relationships on people's competitiveness remains unknown. Grounded in Darwin's theory of sexual selection, this study utilized EEG hyperscanning technology to investigate the influence of the presence of romantic partners and the gender of competitors on the interbrain synchronization of female individuals during competitive contexts. The research results showed that in competitive interactions, there was a significant increase in Theta and Alpha frequency band activity between females and their competitors. Interbrain synchronization was strongest when their partners were not nearby and females competed with same gender competitors. The research results indicate that intimate companionship has an impact on the early alertness and late cognitive execution mechanisms of female individuals in competition, and due to intimate relationships, females pay more attention to same-gender competitors. This study demonstrates that the presence of intimate partners can affect a female's competitive state and brain synchronization with opponents of different genders, improving the theoretical explanation of intimate relationships and competitive interactions.

Many social interactions rely upon mutual information exchange: one member of a pair changes in response to the other while at the same time producing actions that alter the behavior of the other. However, little is known about how such social processes are integrated in the brain. Here, we used a specially designed dual-electroencephalogram system and the conceptual framework of coordination dynamics to identify neural signatures of effective, real-time coordination between people and its breakdown or absence. High-resolution spectral analysis of electrical brain activity before and during visually mediated social coordination revealed a marked depression in occipital alpha and rolandic mu rhythms during social interaction that was independent of whether behavior was coordinated or not. In contrast, a pair of oscillatory components (phi 1 and phi 2 ) located above right centro-parietal cortex distinguished effective from ineffective coordination: increase of phi 1 favored independe...

Imitation has been hailed as 'social glue', facilitating rapport with others. Previous studies suggest that social cues modulate imitation but the mechanism of such modulation remains underspecified. Here we examine the locus, specificity, and neural basis of the social control of imitation. Social cues (group membership and eye gaze) were manipulated during an imitation task in which imitative and spatial compatibility could be measured independently. Participants were faster to perform compatible compared to incompatible movements in both spatial and imitative domains. However, only spatial compatibility was modulated by social cues: an interaction between group membership and eye gaze revealed more spatial compatibility for ingroup members with direct gaze and outgroup members with averted gaze. The fMRI data were consistent with this finding. Regions associated with the control of imitative responding (temporoparietal junction, inferior frontal gyrus) were more active during imitatively incompatible compared to imitatively compatible trials. However, this activity was not modulated by social cues. On the contrary, an interaction between group, gaze and spatial compatibility was found in the dorsolateral prefrontal cortex in a pattern consistent with reaction times. This region may be exerting control over the motor system to modulate response inhibition.

The capacity to integrate multiple sources of information is a prerequisite for complex cognitive ability, such as finding a target uniquely identifiable by the conjunction of two or more features. Recent studies identified greater frontal-parietal synchrony during conjunctive than non-conjunctive (feature) search. Whether this difference also reflects greater information integration, rather than just differences in cognitive strategy (e.g., top-down versus bottom-up control of attention), or task difficulty is uncertain. Here, we examine the first possibility by parametrically varying the number of integrated sources from one to three and measuring phase-locking values (PLV) of frontal-parietal EEG electrode signals, as indicators of synchrony. Linear regressions, under hierarchical false-discovery rate control, indicated significant positive slopes for number of sources on PLV in the 30-38 Hz, 175-250 ms post-stimulus frequency-time band for pairs in the sagittal plane (i.e., F3-P3, Fz-Pz, F4-P4), after equating conditions for behavioural performance (to exclude effects due to task difficulty). No such effects were observed for pairs in the transverse plane (i.e., F3-F4, C3-C4, P3-P4). These results provide support for the idea that anterior-posterior phase-locking in the lower gamma-band mediates integration of visual information. They also provide a potential window into cognitive development, seen as developing the capacity to integrate more sources of information.

Body and brain undergo several changes with aging. One of these changes is the loss of neuroplasticity, which leads to the decrease of cognitive abilities. Hence the necessity of stopping or reversing these changes is of utmost importance to contemporary society. In the present work, electroencephalogram (EEG) markers of cognitive decline are sought whilst the subjects perform the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young and elder participants. The results suggest that coherence on theta and alpha EEG rhythms decrease with aging and increase with performance. Additionally, theta phase coherence seems more sensitive to performance, while alpha synchronization appears as a potential ageing marker.

Discrepancies between what children expect about physical causality (indexed by looking time) and how they act on that knowledge have led to criticisms of claims about what infants "know." Baillargeon [Baillargeon, R. (1999). Young infants' expectations about hidden objects: A reply to three challenges. Developmental Science, 2, 115-163] advocates examining more tasks before revising views of early cognitive development. We report another discrepancy which suggests an additional indicator of what is salient for preverbal infants. While examining the Užgiris-Hunt test performances of 40 children (26 females), 7.6-26.9-months-old, infants appeared captivated by the bouncing of a small rubber ball. However, most infants reproduced the motion of the bounce event itself, repeatedly hitting the ball against the table, rather than the experimenter's action (dropping). Comparing performances of those who did and did not imitate the drop, two possibly interrelated interpretations remained consistent with the data: infants perform goal-directed imitation of interesting phenomena, perhaps because they believe they must apply force to make them happen.

The feeling of being excluded from a social interaction triggers social pain, a sensation as intense as actual physical pain. Little is known about the neurophysiological underpinnings of social pain. We addressed this issue using intracranial electroencephalography in 15 patients performing a ball game where inclusion and exclusion blocks were alternated. Time-frequency analyses showed an increase in power of theta-band oscillations during exclusion in the anterior insula (AI) and posterior insula, the subgenual anterior cingulate cortex (sACC), and the fusiform "face area" (FFA). Interestingly, the AI showed an initial fast response to exclusion but the signal rapidly faded out. Activity in the sACC gradually increased and remained significant thereafter. This suggests that the AI may signal social pain by detecting emotional distress caused by the exclusion, whereas the sACC may be linked to the learning aspects of social pain. Theta activity in the FFA was time-locked to the observation of a player poised to exclude the participant, suggesting that the FFA encodes the social value of faces. Taken together, our findings suggest that theta activity represents the neural signature of social pain. The time course of this signal varies across regions important for processing emotional features linked to social information.

If the state of conscious perception appreciably modulates the levels of synchronies in several frequency bands and cerebral areas, then each one of these levels has a certain capacity of discriminating the subjects perceptual consciousness. Combination of all measurements of these multiple levels of synchronies within a compound index, must make it possible to distinguish, in an optimal way, the state of subjects conscious or not conscious perception. Such an index was searched and identified in our study by using an experimental procedure putting alternatively the subject in a situation inducing a conscious and not conscious perception of famous and unknown faces. The synchronies varied significantly between the perceived and not perceived faces, particularly in the theta, alpha and gamma bands but they were specific to the subject and the face category. Existence of an unconscious perception of facial identity was showed in spite of the realization of a face detection task.

Imitation has been hailed as 'social glue', facilitating rapport with others. Previous studies suggest that social cues modulate imitation but the mechanism of such modulation remains underspecified. Here we examine the locus, specificity, and neural basis of the social control of imitation. Social cues (group membership and eye gaze) were manipulated during an imitation task in which imitative and spatial compatibility could be measured independently. Participants were faster to perform compatible compared to incompatible movements in both spatial and imitative domains. However, only spatial compatibility was modulated by social cues: an interaction between group membership and eye gaze revealed more spatial compatibility for ingroup members with direct gaze and outgroup members with averted gaze. The fMRI data were consistent with this finding. Regions associated with the control of imitative responding (temporoparietal junction, inferior frontal gyrus) were more active during imitatively incompatible compared to imitatively compatible trials. However, this activity was not modulated by social cues. On the contrary, an interaction between group, gaze and spatial compatibility was found in the dorsolateral prefrontal cortex in a pattern consistent with reaction times. This region may be exerting control over the motor system to modulate response inhibition.

Interbrain synchrony (IBS) has been increasingly studied in accordance with the conceptual development of two-person neuroscience, which views neural activities from interacting individuals as a single functional unit.

IBS is usually found to be stronger in collaborative than non-collaborative interactions. However, this approach has not been employed in social anxiety (SA) research.
The current study investigated the relationship between IBS and SA using a prisoner’s dilemma game with a focus on the frontal lobe.

BACKGROUND & AIMS: Early reports suggest that both fecal shedding and dysbiosis of the gut microbiome are associated to disease severity in COVID-19 patients. We investigated the gut microbiome as well as the prevalence of SARS-CoV-2 in stool samples from two French populations: exposed healthcare workers and elderly hospitalized COVID-19 patients. The predictive power of bacterial loss of diversity and detection of SARS-CoV-2 in stool was assessed at 4 weeks against clinical outcomes in the patient group. METHODS: 79 healthcare workers in contact with COVID-19 patients and 64 elderly patients hospitalised in a COVID-19 unit in France were included in the EDIFICE trial from April 2020 until May 2021. Stool samples were collected at inclusion. Loss of bacterial diversity was diagnosed based on 16S rRNA gene sequencing. Stool positivity to SARS-CoV-2 was determined by RT-PCR. Clinical outcomes were recorded at a 4 weeks follow up visit. In particular, these include whether the patient...

Previous studies have reported that imitative responses may be modulated by top-down social factors such as self-focus. However, growing evidence suggests that such social factors may actually modulate domain-general processes such as spatially compatible responding, rather than specifically social processes such as imitation. In this study, we aimed to identify the cognitive processes being modulated under conditions of heightened or diminished self-focus. Participants performed a stimulus-response compatibility task which independently measures both spatial and imitative response tendencies, under two conditions: heightened self-focus, where the task was performed in the presence of two mirrors; and diminished self-focus, where the mirrors were covered. While participants were faster to respond to compatible trials than to incompatible trials, both imitatively and spatially, there was no significant modulation of either spatial or imitative compatibility by self-focus; although the magnitude of the modulation of spatial compatibility was numerically similar to the effect of self-focus on imitation found in previous studies. These results provide no evidence for an effect of self-focus on either socialspecific, or domain-general, processes.

Music’s deeply interpersonal nature suggests that music-derived neuroplasticity relates to interpersonal temporal dynamics, or synchrony. Interpersonal neural synchrony (INS) has been found to correlate with increased behavioral synchrony during social interactions and may represent mechanisms that support them. As social interactions often do not have clearly delineated boundaries, and many start and stop intermittently, we hypothesize that a neural signature of INS may be detectable following an interaction. The present study aimed to investigate this hypothesis using a pre-post paradigm, measuring interbrain phase coherence before and after a cooperative dyadic musical interaction. Ten dyads underwent synchronous electroencephalographic (EEG) recording during silent, non-interactive periods before and after a musical interaction in the form of a cooperative tapping game. Significant post-interaction increases in delta band INS were found in the post-condition and were positively ...

It has been discussed that neural phase-synchrony across distant cortical areas (or global phase-synchrony) was correlated with various aspects of consciousness. The generating process of the synchrony, however, remains largely unknown. As a first step, we investigate transient process of global phase-synchrony, focusing on phase-synchronized clusters. We hypothesize that the phase-synchronized clusters are dynamically organized before global synchrony and clustering patterns depend on perceptual conditions. In an EEG study, Kitajo reported that phase-synchrony across distant cortical areas was selectively enhanced by top-down attention around 4 Hz in Necker cube perception. Here, we further analyzed the phase-synchronized clusters using hierarchical clustering which sequentially binds up the nearest electrodes based on similarity of phase locking between the cortical signals. First, we classified dominant components of the phase-synchronized clusters over time. We then investigated...

Humans make eye-contact to extract information about other people’s mental states, recruiting dedicated brain networks that process information about the self and others. Recent studies show that eye-contact increases the synchronization between two brains. We investigated how eye-contact affects the frequency and direction of the synchronization within and between brains and the characteristics of the dual brain network (i.e. hyperbrain). Eye-contact was associated with higher coherence in the gamma frequency band (30-45Hz) for between and within brain connections. Network analysis revealed that some brain areas served as hubs which linked within- and between- brain networks (midparietal, midfrontal and right parietal areas). Friends showed more efficient eye-contact hyperbrain networks than strangers. During eye-contact, some dyads spontaneously adopted leader/follower roles, resulting in an increase in synchronization from leader to follower (interbrain) in the alpha frequency ba...

Alexithymia is a subclinical condition traditionally characterized by difficulties identifying and describing one's own emotions. Recent formulations of alexithymia, however, suggest that the condition may result from a generalized impairment in the perception of all bodily signals ("interoception"). Interoceptive accuracy has been associated with a variety of deficits in social cognition, but recently with an improved ability to inhibit the automatic tendency to imitate the actions of others. The current study tested the consequences for social cognition of the hypothesized association between alexithymia and impaired interoception by examining the relationship between alexithymia and the ability to inhibit imitation. If alexithymia is best characterized as a general interoceptive impairment, then one would predict that alexithymia would have the same relationship with the ability to control imitation as does interoceptive accuracy. Forty-three healthy adults complete...

Previous studies have reported that imitative responses may be modulated by top-down social factors such as self-focus. However, growing evidence suggests that such social factors may actually modulate domain-general processes such as spatially compatible responding, rather than specifically social processes such as imitation. In this study, we aimed to identify the cognitive processes being modulated under conditions of heightened or diminished self-focus. Participants performed a stimulus-response compatibility task which independently measures both spatial and imitative response tendencies, under two conditions: heightened self-focus, where the task was performed in the presence of two mirrors; and diminished self-focus, where the mirrors were covered. While participants were faster to respond to compatible trials than to incompatible trials, both imitatively and spatially, there was no significant modulation of either spatial or imitative compatibility by self-focus; although the magnitude of the modulation of spatial compatibility was numerically similar to the effect of self-focus on imitation found in previous studies. These results provide no evidence for an effect of self-focus on either socialspecific, or domain-general, processes.

Music’s deeply interpersonal nature suggests that music-derived neuroplasticity relates to interpersonal temporal dynamics, or synchrony. Interpersonal neural synchrony (INS) has been found to correlate with increased behavioral synchrony during social interactions and may represent mechanisms that support them. As social interactions often do not have clearly delineated boundaries, and many start and stop intermittently, we hypothesize that a neural signature of INS may be detectable following an interaction. The present study aimed to investigate this hypothesis using a pre-post paradigm, measuring interbrain phase coherence before and after a cooperative dyadic musical interaction. Ten dyads underwent synchronous electroencephalographic (EEG) recording during silent, non-interactive periods before and after a musical interaction in the form of a cooperative tapping game. Significant post-interaction increases in delta band INS were found in the post-condition and were positively ...

We used dual electroencephalography (EEG) to measure brain activity simultaneously in pairs of trustors and trustees playing a 15-round trust game framed as a "trust game" versus a "power game". Four major findings resulted: first, earnings in each round were higher in the trust than in the power game. Second, in the trust game, reaction time for strategic deliberations was significantly longer for the trustee than the trustor. In the power game, however, the trustee took longer to think about how much money to repay, whereas the trustor took longer to think about how much money to invest. Third, prediction accuracy for the amount exchanged was higher in the trust game than in the power game. Fourth, interbrain synchronicity gauged with the phase-locking value of alpha bands in the brainespecially the frontal and central regionswas higher in the power game than in the trust game. We infer that this last finding reflects elevated mutual strategic deliberation in the power game. These behavioral and neuroscience-based findings give a better understanding of the framing effects of a trust game on the strategic deliberations of both trustor and trustee seeking to attain wealth.

Alexithymia is a sub-clinical condition traditionally characterized by difficulties identifying and describing one‘s own emotions. Recent formulations of alexithymia, however, suggest that the condition may result from a generalized impairment in the perception of all bodily signals ( ̳interoception‘). Interoceptive accuracy has been associated with a variety of deficits in social cognition, but recently with an improved ability to inhibit the automatic tendency to imitate the actions of others. The current study tested the consequences for social cognition of the hypothesized association between alexithymia and impaired interoception by examining the relationship between alexithymia and the ability to inhibit imitation. If alexithymia is best characterized as a general interoceptive impairment, then one would predict that alexithymia would have the same relationship with the ability to control imitation as does interoceptive accuracy. 43 healthy adults completed measures of alexith...

People are embedded in social interaction that shapes their brains throughout lifetime. Instead of emerging from lower-level cognitive functions, social interaction could be the default mode via which humans communicate with their environment. Should this hypothesis be true, it would have profound implications on how we think about brain functions and how we dissect and simulate them. We suggest that the research on the brain basis of social cognition and interaction should move from passive spectator science to studies including engaged participants and simultaneous recordings from the brains of the interacting persons.

Oscillations have been increasingly recognized as a core property of neural responses that contribute to spontaneous, induced, and evoked activities within and between individual neurons and neural ensembles. They are considered as a prominent mechanism for information processing within and communication between brain areas. More recently, it has been proposed that interactions between periodic components at different frequencies, known as cross-frequency couplings, may support the integration of neuronal oscillations at different temporal and spatial scales. The present study details methods based on an adaptive frequency tracking approach that improve the quantification and statistical analysis of oscillatory components and cross-frequency couplings. This approach allows for time-varying instantaneous frequency, which is particularly important when measuring phase interactions between components. We compared this adaptive approach to traditional band-pass filters in their measurement of phase-amplitude and phase-phase cross-frequency couplings. Evaluations were performed with synthetic signals and EEG data recorded from healthy humans performing an illusory contour discrimination task. First, the synthetic signals in conjunction with Monte Carlo simulations highlighted two desirable features of the proposed algorithm vs. classical filter-bank approaches: resilience to broad-band noise and oscillatory interference. Second, the analyses with real EEG signals revealed statistically more robust effects (i.e. improved sensitivity) when using an adaptive frequency tracking framework, particularly when identifying phase-amplitude couplings. This was further confirmed after generating surrogate signals from the real EEG data. Adaptive frequency tracking appears to improve the measurements of cross-frequency couplings through precise extraction of neuronal oscillations.

Both the putative mirror neuron system (pMNS) and the ventral medial prefrontal cortex (vmPFC) are deemed important for social interaction: the pMNS because it supposedly "resonates" with the actions of others, the vmPFC because it is involved in mentalizing. Strictly speaking, the resonance property of the pMNS has never been investigated. Classical functional MRI experiments have only investigated whether pMNS regions augment their activity when an action is seen or executed. Resonance, however, entails more than only "going on and off together". Activity in the pMNS of an observer should continuously follow the more subtle changes over time in activity of the pMNS of the actor. Here we directly explore whether such resonance indeed occurs during continuous streams of actions. We let participants play the game of charades while we measured brain activity of both gesturer and guesser. We then applied a method to localize directed influences between the brains of the participants: between-brain Granger-causality mapping. Results show that a guesser's brain activity in regions involved in mentalizing and mirroring echoes the temporal structure of a gesturer's brain activity. This provides evidence for resonance theories and indicates a fine-grained temporal interplay between regions involved in motor planning and regions involved in thinking about the mental states of others. Furthermore, this method enables experiments to be more ecologically valid by providing the opportunity to leave social interaction unconstrained. This, in turn, would allow us to tap into the neural substrates of social deficits such as autism spectrum disorder. Granger causality | mirror system | social interaction | theory of mind | functional MRI

Although prior research has extensively investigated individual flow, research on group flow is nascent. Individual level flow is a mental state in which a person is fully focused on, involved in, and enjoying the task at hand, and researchers have started to investigate flow episodes involving more than one person (Heyne et al. 2011; Walker 2010). It is argued that flow in a group context "may be a qualitatively different phenomenon than flow experience in isolation"(Walker 2010)(p.4). Literature on social psychology provides ample evidence that action, cognition, and emotions of individuals are different than groups (Fiske et al. 2010). Survey studies report that group flow episodes were rated more enjoyable than those under solitary conditions(Walker 2010). Some studies suggest a correlation between the aggregate flow of the team members and the performance in a planning task (Heyne et al. 2011). Investigating the influence of flow in group contexts on group performance is important because it may contribute to more productive, collaborative, and often geographically distributed, IT enabled work environments.

In memoriam Line Garnero (1955-2009) : la pluridisciplinarité au coeur. Hommage à Line Garnero, directrice de recherche de première classe au CNRS ଝ Abtract Line Garnero passed away in the night between July 12 and 13, 2009 after an intense but too short a battle against cancer. Line was one of the most active scientific figures of the medical imaging community. A major motivation to Line has always been to facilitate communication and mutual understanding amongst her collaborators, to help them build strong multidisciplinary partnerships and projects. In that respect, she was a visionary of the evolution in the organization and conceptions of academic research for multidisciplinary research. She has always been a strong proponent of an open and translational approach to research in applied science, within her group, her laboratory and as a Deputy Director of the new Research Center of the Brain and Spinal Chord Institute which has been inaugurated just recently on the campus of La Salpêtrière Hospital in Paris (France). This research center illustrates the multidisciplinary approach that Line cherished and nurtured all along her career: 400 scientists are now sharing the same environment and workspace to work on all aspects of neuroscience research: from genes to behavior and neuroimaging. This short text is a tribute to Line, and an attempt from some of her closest collaborators, to summarize her major contributions.

Brain correlates of the sense of agency have recently received increased attention. However, the explorations remain largely restricted to the study of brains in isolation. The prototypical paradigm used so far consists of manipulating visual perception of own action while asking the subject to draw a distinction between self-versus externally caused action. However, the recent definition of agency as a multifactorial phenomenon combining bottom-up and top-down processes suggests the exploration of more complex situations. Notably there is a need of accounting for the dynamics of agency in a two-body context where we often experience the double faceted question of who is at the origin of what in an ongoing interaction. In a dyadic context of role switching indeed, each partner can feel body ownership, share a sense of agency and altogether alternate an ascription of the primacy of action to self and to other. To explore the brain correlates of these different aspects of agency, we recorded with dual EEG and video setups 22 subjects interacting via spontaneous versus induced imitation (II) of hand movements. The differences between the two conditions lie in the fact that the roles are either externally attributed (induced condition) or result from a negotiation between subjects (spontaneous condition). Results demonstrate dissociations between self-and other-ascription of action primacy in delta, alpha and beta frequency bands during the condition of II. By contrast a similar increase in the low gamma frequency band (38-47 Hz) was observed over the centro-parietal regions for the two roles in spontaneous imitation (SI). Taken together, the results highlight the different brain correlates of agency at play during live interactions.

Using a dual EEG setup , pairs of subjects jointly performed finger movement tasks under three conditions: intrinsicignore; in-phase-follow; and antiphase-oppose their partner's movement patterns. Group ICA was employed for signal decomposition in the 10-12 Hz range. Mutual information across dyads was estimated in tasks relative to baseline. Results demonstrated information encoding (between partners) in the anti-phase was two times more than the intrinsic which in turn expressed twice as much information content as the more automatic in-phase task. Topography of significant components revealed involvement of the frontal brain region in the intrinsic; both frontal and occipital brain regions in anti-phase suggesting decision making and employment of visual resources in these tasks.

In memoriam Line Garnero (1955-2009) : la pluridisciplinarité au coeur. Hommage à Line Garnero, directrice de recherche de première classe au CNRS ଝ Abtract Line Garnero passed away in the night between July 12 and 13, 2009 after an intense but too short a battle against cancer. Line was one of the most active scientific figures of the medical imaging community. A major motivation to Line has always been to facilitate communication and mutual understanding amongst her collaborators, to help them build strong multidisciplinary partnerships and projects. In that respect, she was a visionary of the evolution in the organization and conceptions of academic research for multidisciplinary research. She has always been a strong proponent of an open and translational approach to research in applied science, within her group, her laboratory and as a Deputy Director of the new Research Center of the Brain and Spinal Chord Institute which has been inaugurated just recently on the campus of La Salpêtrière Hospital in Paris (France). This research center illustrates the multidisciplinary approach that Line cherished and nurtured all along her career: 400 scientists are now sharing the same environment and workspace to work on all aspects of neuroscience research: from genes to behavior and neuroimaging. This short text is a tribute to Line, and an attempt from some of her closest collaborators, to summarize her major contributions.

The survival of the global economy is rooted in the production of goods, rendering of valuable services, and formulation and implementation of favorable trade policies. These goods and services supported by related policies however, must reach prospective customers unblemished in good time, through planned advertisement strategies. Advertisement over the years has evolved from the traditional one-on-one to technology induced ones such as digital marketing and sales. Technological advancement has diversified advertisement into a multi-faceted and dynamic channel with enormous growth and prospects. In this paper, we made a significant effort to identify actual online data to justify why short video (SV) adoption is essential in e-commerce and digital marketing. A total of 23589 datasets were drawn from three global B2C and C2C websites using the scrappy web crawlers to investigate a resilience model in the relationship between SV advertising adoption, quality signals, customer satisfa...

During social interaction, both participants are continuously active, each modifying their own actions in response to the continuously changing actions of the partner. This continuous mutual adaptation results in interactional synchrony to which both members contribute. Freely exchanging the role of imitator and model is a well-framed example of interactional synchrony resulting from a mutual behavioral negotiation. How the participants' brain activity underlies this process is currently a question that hyperscanning recordings allow us to explore. In particular, it remains largely unknown to what extent oscillatory synchronization could emerge between two brains during social interaction. To explore this issue, 18 participants paired as 9 dyads were recorded with dual-video and dual-EEG setups while they were engaged in spontaneous imitation of hand movements. We measured interactional synchrony and the turn-taking between model and imitator. We discovered by the use of nonlinear techniques that states of interactional synchrony correlate with the emergence of an interbrain synchronizing network in the alpha-mu band between the right centroparietal regions. These regions have been suggested to play a pivotal role in social interaction. Here, they acted symmetrically as key functional hubs in the interindividual brainweb. Additionally, neural synchronization became asymmetrical in the higher frequency bands possibly reflecting a top-down modulation of the roles of model and imitator in the ongoing interaction.

Recently, the neuroscience field took a particular interest in the use of a neuroimaging technique called 'hyperscanning'. This new technique consists in the simultaneous recording of the hemodynamic or neuroelectric activities of multiple subjects. Behind this small technical step lays a giant methodological leap. Groundbreaking insight in the understanding of social cognition shall be achieved if the right paradigms are implemented. A growing number of studies demonstrate the potential of this recent technique. In this paper, we will focus on current issues and future perspectives of brain studies using hyperscanning. We will also add to this review two studies initiated by Line Garnero. These studies will illustrate the promising possibilities offered by hyperscanning through two different key phenomena pertaining to social interaction: gesture imitation and joint attention.

The mechanisms underlying analgesia related to social touch are not clear. While recent research highlights the role of the empathy of the observer to pain relief in the target, the contribution of social interaction to analgesia is unknown. The current study examines brain-to-brain coupling during pain with interpersonal touch and tests the involvement of interbrain synchrony in pain alleviation. Romantic partners were assigned the roles of target (pain receiver) and observer (pain observer) under pain-no-pain and touch-no-touch conditions concurrent with EEG recording. Brain-to-brain coupling in alpha-mu band (8-12 Hz) was estimated by a three-step multilevel analysis procedure based on running window circular correlation coefficient and post hoc power of the findings was calculated using simulations. Our findings indicate that hand-holding during pain administration increases brain-to-brain coupling in a network that mainly involves the central regions of the pain target and the ...

The paper highlights the discrepancy between newborns' communication disability and their successful performance in social tasks. The author believes that the "blank mind" can only acquire social meanings by social interaction; it is the only possible way of knowledge acquisition that obeys Nature's laws. There is no other mechanism of transmitting information about social reality to the "blank mind", which can help newborns succeed in imitation. In specific, the article discusses: (1) the terms "early imitation" and "imitation", showing them as two different phenomena of mirror actions in, respectively, newborns and infants (at 8-12 month-olds); (2) the lack of evidence on matching in studies may show that experiments on "early imitation" did not consider emotional arousal as an independent variable of their research; (3) the problem of Primary Data Entry (PDE), how a "blank mind" acquires the first social meanings to initiate knowledge acquisition.

This study aims to give a comprehensive insight into the drive of online shopping among tertiary students in Ghana, considering the role of attitude and subjective norm. With the technique of convenience sampling, the data were gathered from Ghanaian tertiary students via a web survey. In all, the self-administrated questionnaire consisted of 400 respondents. In analyzing the data, SmartPLS version 3.2.9 was used. The findings revealed that recommendations have a significant positive effect on purchase intention, attitude, and subjective norms. Also, it was realized that there is a significant positive effect of online reviews on purchase intention, attitude, and subjective norm. Lastly, though there was no significant influence of attitude on purchase intention, subjective norms positively influenced purchase intention. In all, these findings show that a favorable online review and recommendations by an earlier user will eventually trigger a positive purchase intention, among others. The results are valuable to the growth and expansion of online shops. It admonishes that being able to meet early online consumers' needs and giving attention to their feedback is very instrumental in attracting other consumers.

Available at: https://www.imperialpublications.com/image/catalog/JAMARV225.pdf

Individuals in pain are motivated to be cooperative in social interaction. Yet, there has been little research on how pain dynamically affects cooperation at a neural level. The present study investigated the cooperative behavior under acute physical pain by asking dyads to complete three blocks of button-press cooperative task, while neural activities were recorded simultaneously on each subject by the fNIRS-based hyperscanning. Results showed that individuals in pain improved their cooperation rate across task blocks.

Individuals in pain are motivated to be cooperative in social interaction. Yet, there has been little research on how pain dynamically affects cooperation at a neural level. The present study investigated the cooperative behavior under acute physical pain by asking dyads to complete three blocks of button-press cooperative task, while neural activities were recorded simultaneously on each subject by the fNIRS-based hyperscanning. Results showed that individuals in pain improved their cooperation rate across task blocks.

When trying to remember verbal information from memory, people look at spatial locations that have been associated with visual stimuli during encoding, even when the visual stimuli are no longer present. It has been shown that such "eye movements to nothing" can influence retrieval performance for verbal information, but the mechanism underlying this functional relationship is unclear. More precisely, covert in comparison to overt shifts of attention could be sufficient to elicit the observed differences in retrieval performance. To test if covert shifts of attention explain the functional role of the looking-at-nothing phenomenon, we asked participants to remember verbal information that had been associated with a spatial location during an encoding phase. Additionally, during the retrieval phase, all participants solved an unrelated visual tracking task that appeared in either an associated (congruent) or an incongruent spatial location. Half the participants were instru...

Recent advances in brain sciences have enabled the co-recording of multiple interacting brains (i.e., hyperscanning [1]). This technique has led to the discovery of inter-brain synchrony (IBS) between people involved in social and interactive scenarios. In a recent article, Novembre and Iannetti argued that studies using hyperscanning to understand social behaviors are crucial but limited to correlational analysis [2]. They further developed the idea that the causal role of IBS can only be apprehended through multi-brain stimulation (MBS). Although we agree with Novembre and Iannetti that MBS is one of the most promising methods for investigating inter-brain coupling in the future, we disagree on their radical claim that it constitutes ‘the only validated empirical approach capable of teasing apart the mechanistic from the epiphenomenal interpretation of inter-brain synchrony’. In this Letter, we defend the idea that explaining IBS in terms of causal mechanisms is possible through adequate experimental designs and computational tools, with empirical approaches ranging from multi-brains (hyperscanning) to single-brain (classic social neuroscience) recordings, and even no-brain (i.e., in silico computational social neuroscience).

The human brain has undergone massive expansion across primate evolution through life amidst multi-layered social attachments; within families, among friends, and between clan members and this enabled humans to coordinate their brains with those of others toward the execution of complex social goals. We examined how human attachments facilitate efficient, resource-sensitive performance of social goals by balancing neural and behavioral synchrony. Using hyperscanning EEG, we collected neural data from male-female pairs in three groups (N = 158, 79 pairs); long-term couples, best friends, and unfamiliar group members, during two ecologically-valid natural-istic tasks; motor coordination and empathy giving. Across groups and tasks, neural synchrony was supported by behavior coordination and orchestrated multiple neural rhythms. In the goal-directed motor task, interbrain syn-chrony implicated beta and gamma rhythms localized to sensorimotor areas. Couples showed the highest neural synchrony combined with greatest behavioral synchrony and such brain-behavior linkage resulted in speedy performance , conserving energy in the long run. The socially-oriented empathy task triggered neural synchrony in widely-distributed sensorimotor and bilateral temporal regions, integrated alpha, beta, and gamma rhythms, and implicated brain-behavior complementarity ; couples displayed the highest behavioral synchrony combined with lowest neural synchrony toward greatest felt support while strangers exhibited the opposite pattern. Findings suggest that human attachments provide a familiar backdrop of temporal regularities, required for the brain's allostatic function, and interbrain and behavioral synchrony are sculpted by familiarity and closeness toward resource-sensitive performance of survival-related social goals, toiled by two.

The purpose of this review paper is to present the application of herding behavior in online buying. The simplest description of herding behavior is the imitation of others in making decisions. Online buying platforms have facilitated observing others' buying behavior, thereby increasing possibilities of social influence on our information search, evaluation, and buying. The concept of herding is multidisciplinary ; however, the literature review on herding behavior is mainly grounded in economics and finance. There is little understanding of herding behavior in marketing literature. Therefore, this study covers herding behavior literature through high-quality research papers published from 2000 to 2020 in journals indexed in the social science citation index, science citation index expanded, and emerging source citation index. This paper discusses the conceptualization of herding in online buying, herding situations, information-processing view of herding, measuring herding effect, herding models and theories, and areas for future research to enrich herding literature in online buying. This paper proposes a herding model (HCMMD) based on the stimulus-organism-response (SOR) theory to study herding behavior.

Using a dual EEG set-up, pairs of subjects jointly performed finger movement tasks under three conditions: intrinsicignore; in-phase -follow; and antiphase -oppose their partner's movement patterns. Group ICA was employed for signal decomposition in the 10-12 Hz range. Mutual information across dyads was estimated in tasks relative to baseline. Results demonstrated information encoding (between partners) in the anti-phase was two times more than the intrinsic which in turn expressed twice as much information content as the more automatic in-phase task. Topography of significant components revealed involvement of the frontal brain region in the intrinsic; both frontal and occipital brain regions in anti-phase suggesting decision making and employment of visual resources in these tasks.

Using a dual EEG set-up, pairs of subjects jointly performed finger movement tasks under three conditions: intrinsicignore; in-phase -follow; and antiphase -oppose their partner's movement patterns. Group ICA was employed for signal decomposition in the 10-12 Hz range. Mutual information across dyads was estimated in tasks relative to baseline. Results demonstrated information encoding (between partners) in the anti-phase was two times more than the intrinsic which in turn expressed twice as much information content as the more automatic in-phase task. Topography of significant components revealed involvement of the frontal brain region in the intrinsic; both frontal and occipital brain regions in anti-phase suggesting decision making and employment of visual resources in these tasks.

Automaticity has been argued to be a core feature of the mental processes that guide social interactions, such as those underpinning imitative behaviors. To date, however, there is little known about the automaticity of imitative tendencies. In the current study, we used a finger movement stimulus-response compatibility task to index processes associated with controlling the urge to copy other people's actions. In addition, we manipulated the level of load placed on a secondary cognitive task to test if there is a capacity limit in the systems that filter distractor finger movement stimuli. Across three experiments, we showed that whether letter strings (Experiment 1), faces (Experiment 2), or hand postures (Experiment 3) are held in working memory, there was no impact on compatibility effects in the main task. These findings show that the cognitive operations that generate imitative tendencies are relatively efficient in that they operate the same whether or not a central resource is taxed heavily with nonsocial (letter strings) or social stimuli (faces and hand postures). Therefore, in the sense of persisting in the presence of a demanding cognitive load, this type of imitation behavior can be considered automatic. Public Significance Statement This study strongly suggests that the mental processes underpinning imitative behavior are relatively automatic, such that they are unaffected when concurrently performing a demanding secondary task.

The mechanisms underlying analgesia related to social touch are not clear. While recent research highlights the role of the empathy of the observer to pain relief in the target, the contribution of social interaction to analgesia is unknown. The current study examines brain-to-brain coupling during pain with interpersonal touch and tests the involvement of interbrain synchrony in pain alleviation. Romantic partners were assigned the roles of target (pain receiver) and observer (pain observer) under pain–no-pain and touch–no-touch conditions concurrent with EEG recording. Brain-to-brain coupling in alpha–mu band (8–12 Hz) was estimated by a three-step multilevel analysis procedure based on running window circular correlation coefficient and post hoc power of the findings was calculated using simulations. Our findings indicate that hand-holding during pain administration increases brain-to-brain coupling in a network that mainly involves the central regions of the pain target and the right hemisphere of the pain observer. Moreover, brain-to-brain coupling in this network was found to correlate with analgesia magnitude and observer’s empathic accuracy. These findings indicate that brain-to-brain coupling may be involved in touch-related analgesia.

During joint actions, people typically adjust their own actions according to the ongoing actions of the partner, which implies that the interaction modulates the behavior of both participants. However, the neural substrates of such mutual adaptation are still poorly understood. Here, we set out to identify the kinematics-related brain activity of leaders and followers performing hand actions.
Sixteen participants as 8 pairs performed continuous, repetitive right-hand opening and closing actions with ~3-s cycles in a leader–follower task. Subjects played each role for 5 min. Magnetoencephalographic (MEG) brain signals were recorded simultaneously from both partners with a dual-MEG setup, and hand kinematics was monitored with accelerometers. Modulation index, a cross-frequency coupling measure, was computed between the hand acceleration and the MEG signals in the alpha (7–13 Hz) and beta (13–25 Hz) bands.
Regardless of the participants' role, the strongest alpha and beta modulations occurred bilaterally in the sensorimotor cortices. In the occipital region, beta modulation was stronger in followers than leaders; these oscillations originated, according to beamformer source reconstructions, in early visual cortices. Despite differences in the modulation indices, alpha and beta power did not differ between the conditions.
Our results indicate that the beta modulation in the early visual cortices depends on the subject's role as a follower or leader in a joint hand-action task. This finding could reflect the different strategies employed by leaders and followers in integrating kinematics-related visual information to control their own actions.