Neural substrates of social facilitation effects on incentive-based performance

Inhibiting responses under the watch of a recently synchronized peer increases self-monitoring: evidence from functional near-infrared spectroscopy

Developing motor synchrony with a peer (through interventions such as the mirror game) can yield collaborative, cognitive and social benefits. However, it is also well established that observation by an audience can improve cognition. The combined and relative advantages offered by motor synchronization and audience effects are not yet understood. It is important to address this gap to determine the extent to which synchronizing activities might interact with the positive effects of an audience. In this preregistered study, we investigate the extent to which response inhibition may be improved when observed by a peer after motor synchronization with this peer. We compare behavioural and cortical (functional near-infrared spectroscopy; fNIRS) measures of inhibition between synchronized and non-synchronized dyads and find that the presence of a synchronized peer-audience introduces a speed-accuracy trade-off, consisting of slower reaction times and improved accuracy. This co-occurs with cortical activation in bilateral inferior frontal and middle prefrontal cortices, which are implicated in monitoring and maintenance of social alignment. Our findings have implications for carers and support people, who may benefit from synchronizing activities for rehabilitating inhibition and social skills in clinical settings.

Unraveling dyadic psycho-physiology of social presence between strangers during an audio drama - a signal-analysis approach

A mere co-presence of an unfamiliar person may modulate an individual's attentive engagement with specific events or situations to a significant degree. To understand better how such social presence affects experiences, we recorded a set of parallel multimodal facial and psychophysiological data with subjects (N = 36) who listened to dramatic audio scenes alone or when facing an unfamiliar person. Both a selection of 6 s affective sound clips (IADS-2) followed by a 27 min soundtrack extracted from a Finnish episode film depicted familiar and often intense social situations familiar from the everyday world. Considering the systemic complexity of both the chosen naturalistic stimuli and expected variations in the experimental social situation, we applied a novel combination of signal analysis methods using inter-subject correlation (ISC) analysis, Representational Similarity Analysis (RSA) and Recurrence Quantification Analysis (RQA) followed by gradient boosting classification. We report our findings concerning three facial signals, gaze, eyebrow and smile that can be linked to socially motivated facial movements. We found that ISC values of pairs, whether calculated on true pairs or any two individuals who had a partner, were lower than the group with single individuals. Thus, audio stimuli induced more unique responses in those subjects who were listening to it in the presence of another person, while individual listeners tended to yield a more uniform response as it was driven by dramatized audio stimulus alone. Furthermore, our classifiers models trained using recurrence properties of gaze, eyebrows and smile signals demonstrated distinctive differences in the recurrence dynamics of signals from paired subjects and revealed the impact of individual differences on the latter. We showed that the presence of an unfamiliar co-listener that modifies social dynamics of dyadic listening tasks can be detected reliably from visible facial modalities. By applying our analysis framework to a broader range of psycho-physiological data, together with annotations of the content, and subjective reports of participants, we expected more detailed dyadic dependencies to be revealed. Our work contributes towards modeling and predicting human social behaviors to specific types of audio-visually mediated, virtual, and live social situations.

Task-independent neural bases of peer presence effect on cognition in children and adults

There is ample behavioral evidence that others' mere presence can affect any behavior in human and non-human animals, generally facilitating the expression of mastered responses while impairing the acquisition of novel ones. Much less is known about i) how the brain orchestrates the modulation of such a wide array of behaviors by others' presence and ii) when these neural underpinnings mature during development. To address these issues, fMRI data were collected in children and adults alternately observed and unobserved by a familiar peer. Subjects performed a numerosity comparison task and a phonological comparison task. While the former involves number-processing brain areas, the latter involves language-processing areas. Consistent with previous behavioral findings, adults' and children's performance improved in both tasks when observed by a peer. Across all participants, task-specific brain regions showed no reliable change in activity under peer observation. Rather, we found task-independent changes in domain-general brain regions typically involved in mentalizing, reward, and attention. Bayesian analyses singled out the attention network as the exception to the close child-adult resemblance of peer observation neural substrates. These findings suggest that i) social facilitation of some human education-related skills is primarily orchestrated by domain-general brain networks, rather than by task-selective substrates, and ii) apart from attention, peer presence neural processing is largely mature in children.

The presence of adjacent others facilitates interpersonal neural synchronization in the left prefrontal cortex during a simple addition task

The hyperscanning technique, that is, simultaneous measurement of neural signals in more than one person, is a powerful research tool for understanding humans' social interactions. In recent years, many studies have investigated interpersonal neural synchronization during various types of communication processes. However, there has been little focus on the impact of the presence of others without explicit social interaction, despite the mere presence of others having been suggested as influencing behavior. In this study, we clarify whether neural signals during a self-paced, repeated, addition task are synchronized when another individual is adjacent without direct interaction. Twenty pairs of participants were measured using a hyperscanning approach with near-infrared spectroscopy. The results show that interpersonal neural synchronization of the task-related signal in the left forehead region was enhanced under the condition of being adjacent to another participant. By contrast, a significant decrease in neural synchronization in the center of the forehead region, where increased neural synchronization is often reported in explicit communication, was observed. Thus, the results indicate that the adjacency of others modulates interpersonal neural synchronization in the task-related signal, and the effect on cognitive processing is different from that of explicit social interaction.

Age-Related Differences in Ventral Striatal and Default Mode Network Function During Reciprocated Trust

Social relationships change across the lifespan as social networks narrow and motivational priorities shift to the present. Interestingly, aging is also associated with changes in executive function, including decision-making abilities, but it remains unclear how age-related changes in both domains interact to impact financial decisions involving other people. To study this problem, we recruited 50 human participants (N_younger = 26, ages 18–34; N_older = 24, ages 63–80) to play an economic trust game as the investor with three partners (friend, stranger, and computer) who played the role of investee. Investors underwent functional magnetic resonance imaging (fMRI) during the trust game while investees were seated outside of the scanner. Building on our previous work with younger adults showing both enhanced striatal responses and altered default-mode network (DMN) connectivity as a function of social closeness during reciprocated trust, we predicted that these relations would exhibit age-related differences. We found that striatal responses to reciprocated trust from friends relative to strangers and computers were blunted in older adults relative to younger adults, thus supporting our primary pre-registered hypothesis regarding social closeness. We also found that older adults exhibited enhanced DMN connectivity with the temporoparietal junction (TPJ) during reciprocated trust from friends compared to computers while younger adults exhibited the opposite pattern. Taken together, these results advance our understanding of age-related differences in sensitivity to social closeness in the context of trusting others.

Electroencephalographic Investigation of the Effect of Skill Level and Social Inhibition on Simulated Handgun Shooting

We examined effects of Social Inhibition (SI), and Skill Level (SL) on simulated handgun shooting performance. Electroencephalogram (EEG) was also recorded in order to measure task-related changes in cortical activity. Participants consisted of Novice (NSL) and Experienced (ESL) shooters who were randomly assigned to shoot while in the presence of an audience (Hi SI) or alone (Low SI). The results revealed that NSL were less accurate than ESL in all conditions as was predicted. Shooting accuracy was predicted by alpha and beta amplitude, indicating different roles for attention and anxiety. Prefrontal alpha amplitude was significantly influenced by SL and SI, with a finding that ES showed RH deactivation while NS showed LH deactivation. Findings are discussed in terms of theories of motor control and SI.

Temporal error monitoring with directional error magnitude judgements: a robust phenomenon with no effect of being watched

A key aspect of metacognition is the ability to monitor performance. A recent line of work has shown that error-monitoring ability captures both the magnitude and direction of timing errors, thereby pointing at the metric composition of error monitoring [e.g., Akdoğan and Balcı (J Exp Psychol https://dx.doi.org/10.1037/xge0000265 , 2017)]. These studies, however, primarily used a composite variable that combined isolated measures of ordinal confidence ratings (as a proxy for error magnitude judgement) and "shorter/longer than the target" judgements. In two experiments we tested temporal error monitoring (TEM) performance with a more direct measure of directional error magnitude rating on a continuum. The second aim of this study is to test if TEM performance is modulated by the feeling of being watched that was previously shown to influence metacognitive-like monitoring processes. We predicted that being watched would improve TEM performance, particularly in participants with high timing precision (a proxy for high task mastery), and disrupt TEM performance in participants with low timing precision (a proxy for low task mastery). In both experiments, we found strong evidence for TEM ability. However, we did not find any reliable effect of the social stimulus on TEM performance. In short, our results demonstrate that metric error monitoring is a robust metacognitive phenomenon, which is not sensitive to social influence.

The influence of relationship closeness on default-mode network connectivity during social interactions

Reciprocated trust plays a critical role in forming and maintaining relationships, and has consistently been shown to implicate neural circuits involved in reward-related processing and social cognition. Less is known about neural network connectivity during social interactions involving trust, however, particularly as a function of closeness between an investor and a trustee. We examined network reactivity and connectivity in participants who played an economic trust game with close friends, strangers and a computer. Network reactivity analyses showed enhanced activation of the default-mode network (DMN) to social relative to non-social outcomes. A novel network psychophysiological interaction (nPPI) analysis revealed enhanced connectivity between the DMN and the superior frontal gyrus and superior parietal lobule when experiencing reciprocated vs violated trust from friends relative to strangers. Such connectivity tracked with differences in self-reported social closeness with these partners. Interestingly, reactivity of the executive control network (ECN), involved in decision processes, demonstrated no social vs non-social preference, and ECN-ventral striatum connectivity did not track social closeness. Taken together, these novel findings suggest that DMN interacts with components of attention and control networks to signal the relative importance of positive experiences with close others vs strangers.

Language comprehension in the social brain: Electrophysiological brain signals of social presence effects during syntactic and semantic sentence processing

Although, evolutionarily, language emerged predominantly for social purposes, much has yet to be uncovered regarding how language processing is affected by social context. Social presence research studies the ways in which the presence of a conspecific affects processing, but has yet to be thoroughly applied to language processes. The principal aim of this study was to see how syntactic and semantic language processing might be subject to mere social presence effects by studying Event-Related brain Potentials (ERP). In a sentence correctness task, participants read sentences with a semantic or syntactic anomaly while being either alone or in the mere presence of a confederate. Compared to the alone condition, the presence condition was associated with an enhanced N400 component and a more centro-posterior LAN component (interpreted as an N400). The results seem to imply a boosting of heuristic language processing strategies, proper of lexico-semantic operations, which actually entails a shift in the strategy to process morphosyntactic violations, typically based on algorithmic or rule-based strategies. The effects cannot be related to increased arousal levels. The apparent enhancement of the activity in the precuneus while in presence of another person suggests that the effects conceivably relate to social cognitive and attentional factors. The present results suggest that understanding language comprehension would not be complete without considering the impact of social presence effects, inherent to the most natural and fundamental communicative scenarios.

Predictable real-time constraints reveal anticipatory strategies of coupled planning in a sequential pick and place task

Planning a sequence of two motor elements is much more than concatenating two independent movements. However, very little is known about the cognitive strategies that are used to perform fluent sequences for intentional object manipulation. In this series of studies, the participants’ task was to reach for and pick to place a wooden cylinder to set it on a place pad of three different diameters, which served to modify terminal accuracy constraints. Participants were required to perform the sequences (1) at their preferred speed or (2) as fast as possible. Action kinematics were recorded with the Qualisys motion-capture system in order to implement a real-time protocol to get participants to engage in a true interactive relation. Results revealed that with low internal constraints (at preferred speed), low coupling between the two elements of the motor sequence was observed, suggesting a step-by-step planning strategy. Under high constraints (at fastest speed), an important terminal accuracy effect back propagated to modify early kinematic parameters of the first element, suggesting strong coupling of the parameters in an encapsulated planning strategy. In Studies 2 and 3, we further manipulated instructions and timing constraints to confirm the importance of time and predictability of external information for coupled planning. These findings overall sustain the hypothesis that coupled planning can take place in a pick and place task when anticipatory strategies are possible. This mode of action planning may be the key reason why motor intention can be read through the observation of micro variations in body kinematics.

Peer Presence Effects on Eye Movements and Attentional Performance

"Social facilitation" refers to the enhancement or impairment of performance engendered by the mere presence of others. It has been demonstrated for a diversity of behaviors. This study assessed whether it also concerns attention and eye movements and if yes, which decision-making mechanisms it affects. Human volunteers were tested in three different tasks (saccades, visual search, and continuous performance) either alone or in the presence of a familiar peer. The results failed to reveal any significant peer influence on the visual search and continuous performance tasks. For saccades, by contrast, they showed a negative or positive peer influence depending on the complexity of the testing protocol. Pro-and anti-saccades were both inhibited when pseudorandomly mixed, and both facilitated when performed separately. Peer presence impaired or improved reaction times, i.e., the speed to initiate the saccade, as well as peak velocity, i.e., the driving force moving the eye toward the target. Effect sizes were large, with Cohen's d-values ranging for reaction times (RTs) from 0.50 to 0.95. Analyzing RT distributions using the LATER (Linear Approach to Threshold with Ergodic Rate) model revealed that social inhibition of pro- and anti-saccades in the complex protocol was associated with a significant increase in the rate of rise. The present demonstration that the simple presence of a familiar peer can inhibit or facilitate saccades depending on task difficulty strengthens a growing body of evidence showing social modulations of eye movements and attention processes. The present lack of effect on visual search and continuous performance tasks contrasts with peer presence effects reported earlier using similar tasks, and future studies are needed to determine whether it is due to an intermediate level of difficulty maximizing individual variability. Together with an earlier study of the social inhibition of anti-saccades also using the LATER model, which showed an increase of the threshold, the present increase of the rate of rise suggests that peer presence can influence both the top-down and bottom-up attention-related processes guiding the decision to move the eyes.

Social Impairments in Mental Disorders: Recent Developments in Studying the Mechanisms of Interactive Behavior

Most mental disorders are associated with impairments in social functioning. Paradigms developed to study social functioning in laboratory settings mostly put participants in a detached observer point of view. However, some phenomena are inherently interactive and studying full-blown reciprocal interactions may be indispensable to understand social deficits in psychopathology.

We conducted a narrative review on recent developments in the field of experimental clinical psychology and clinical social neuroscience that employs a second-person approach to studying social impairments in Autism Spectrum Disorder (ASD), Personality Disorder, Social Anxiety Disorder (SAD), and Schizophrenia.

Recent developments in methodological, analytical, and technical approaches, such as dual eye-tracking, mobile eye-tracking, live video-feed, hyperscanning, or motion capture allow for a more ecologically valid assessment of social functioning. In individuals with ASD, these methods revealed reduced sensitivity to the presence of a real interaction partner as well as diminished behavioral and neural synchronicity with interaction partners. Initial evidence suggests that interactive paradigms might be a powerful tool to reveal reduced interpersonal sensitivity in Personality Disorders and increased interpersonal sensitivity in individuals with SAD.

A shift towards adapting a second-person account has clearly benefitted research on social interaction in psychopathology. Several studies showed profound differences in behavioral and neural measures during actual social interactions, as compared to engaging participants as mere observers. While research using truly interactive paradigms is still in its infancy, it holds great potential for clinical research on social interaction.

We review studies adopting a second-person account of social interaction in clinical psychology.

Studies show profound differences between actual social interactions and mere observations.

The full extent of impairments in social functioning unfolds only in complex social interactions.

New methodological developments hold great potential for research on social interaction deficits.

Adolescent cognitive control, theta oscillations, and social observation

Theta oscillations (4-8 Hz) provide an organizing principle of cognitive control, allowing goal-directed behavior. In adults, theta power over medial-frontal cortex (MFC) underlies conflict/error monitoring, whereas theta connectivity between MFC and lateral-frontal regions reflects cognitive control recruitment. However, prior work has not separated theta responses that occur before and immediately after a motor response, nor explained how medial-lateral connectivity drives different kinds of control behaviors. Theta's role during adolescence, a developmental window characterized by a motivation-control mismatch also remains unclear. As social observation is known to influence motivation, this might be a particularly important context for studying adolescent theta dynamics. Here, adolescents performed a flanker task alone or under social observation. Focusing first on the nonsocial context, we parsed cognitive control into dissociable subprocesses, illustrating how theta indexes distinct components of cognitive control working together dynamically to produce goal-directed behavior. We separated theta power immediately before/after motor responses, identifying behavioral links to conflict monitoring and error monitoring, respectively. MFC connectivity was separated before/after responses and behaviorally-linked to reactive and proactive control, respectively. Finally, distinct forms of post-error control were dissociated, based on connectivity with rostral/caudal frontal cortex. Social observation was found to exclusively upregulate theta measures indexing post-response error monitoring and proactive control, as opposed to conflict monitoring and reactive control. Linking adolescent cognitive control to theta oscillations provides a bridge between non-invasive recordings in humans and mechanistic studies of neural oscillations in animal models; links to social observation provide insight into the motivation-control interactions that occur during adolescence.