Partner's Actions Research Articles

Computational joint action: Dynamical models to understand the development of joint coordination.

Coordinating with others is part of our everyday experience. Previous studies using sensorimotor coordination games suggest that human dyads develop coordination strategies that can be interpreted as Nash equilibria. However, if the players are uncertain about what their partner is doing, they develop coordination strategies which are robust to the actual partner's actions. This has suggested that humans select their actions based on an explicit prediction of what the partner will be doing-a partner model-which is probabilistic by nature. However, the mechanisms underlying the development of a joint coordination over repeated trials remain unknown. Very much like sensorimotor adaptation of individuals to external perturbations (eg force fields or visual rotations), dynamical models may help to understand how joint coordination develops over repeated trials. Here we present a general computational model-based on game theory and Bayesian estimation-designed to understand the mechanisms underlying the development of a joint coordination over repeated trials. Joint tasks are modeled as quadratic games, where each participant's task is expressed as a quadratic cost function. Each participant predicts their partner's next move (partner model) by optimally combining predictions and sensory observations, and selects their actions through a stochastic optimization of its expected cost, given the partner model. The model parameters include perceptual uncertainty (sensory noise), partner representation (retention rate and internale noise), uncertainty in action selection and its rate of decay (which can be interpreted as the action's learning rate). The model can be used in two ways: (i) to simulate interactive behaviors, thus helping to make specific predictions in the context of a given joint action scenario; and (ii) to analyze the action time series in actual experiments, thus providing quantitative metrics that describe individual behaviors during an actual joint action. We demonstrate the model in a variety of joint action scenarios. In a sensorimotor version of the Stag Hunt game, the model predicts that different representations of the partner lead to different Nash equilibria. In a joint two via-point (2-VP) reaching task, in which the actions consist of complex trajectories, the model captures well the observed temporal evolution of performance. For this task we also estimated the model parameters from experimental observations, which provided a comprehensive characterization of individual dyad participants. Computational models of joint action may help identifying the factors preventing or facilitating the development of coordination. They can be used in clinical settings, to interpret the observed behaviors in individuals with impaired interaction capabilities. They may also provide a theoretical basis to devise artificial agents that establish forms of coordination that facilitate neuromotor recovery.

Endogenous monitoring through voluntary reporting in an infinitely repeated prisoner's dilemma game: experimental evidence

AbstractExogenous reputational information is known to improve cooperation. This study experimentally investigates how people create such information by reporting their partner's action choices, and whether endogenous monitoring helps to sustain cooperation, in an indefinitely repeated prisoner's dilemma game with random matching. The experimental results show that most subjects report their opponents' action choices, thereby successfully cooperating when reporting does not involve costs. However, when reporting is costly, participants are strongly discouraged from doing so. Consequently, they fail to achieve strong cooperative norms when the reported information is conveyed privately only to their next‐round interaction partners. Costly reporting occurs only occasionally even when there is a public record whereby all future partners can check the reported information, but significantly more frequently relative to the condition in which it is sent to the next partner only. With public records, groups can foster cooperative norms aided by reported information that gradually accumulates and becomes more informative over time.

Gaslighting Exposure During Emerging Adulthood: Personality Traits and Vulnerability Paths.

Among the many forms of psychological violence, gaslighting is a particularly insidious manipulative behaviour that includes acts aimed at controlling and altering one's own partner's sensations, thoughts, actions, affective state, self-perception, and reality-testing. The purpose of this study was to evaluate the association between the experience of gaslighting and dysfunctional aspects of the partner's personality. Gaslighter personality facets were assessed using the Personality Inventory for DSM-5-Informant Form-Adult (PID-5-IRF), while gaslighting behaviours were assessed using a 25-item questionnaire, based on the three categories of glamour, good-guy, and intimidator (Stern, 2007). The sample was made up of a group of 177 Italian emerging adults aged between 19 and 26 (49.2% male, 50.8% female; M = 21.88, SD = 1.75), enrolled at University, who participated voluntarily in the research. In fact, none of them received any form of direct or indirect incentive. In our study, we applied a beta regression model mapping the Likert scale into the open interval (0,1). The main results show (a) good-guy gaslighting is positively associated with manipulativeness and negatively associated with deceitfulness; (b) glamour gaslighting has a negative association with separation insecurity and manipulativeness, but it is positively associated with irresponsibility; (c) intimidator gaslighting has a positive association with separation insecurity and distractibility and a negative association with eccentricity and perceptual dysregulation; (d) all three gaslighting categories are negatively associated with anhedonia and impulsivity. Based on what emerged from the data, aspects such as separation insecurity, irresponsibility, and distractibility can be seen as serious risk factors for gaslighting. For this reason, with regard to clinical implications, an early recognition of dysfunctional traits in potential abusers should be fostered in order to protect both potential abusers and their partner from aggressive conduct within an intimate relationship.

Chimpanzees demonstrate a behavioural signature of human joint action

The strength of human society can largely be attributed to the tendency to work together to achieve outcomes that are not possible alone. Effective social coordination benefits from mentally representing a partner's actions. Specifically, humans optimize social coordination by forming internal action models adapted to joint rather than individual task demands. To what extent do humans share the cognitive mechanisms that support optimal human coordination and collaboration with other species? An ecologically inspired joint handover-to-retrieve task was systematically manipulated across several experiments to assess whether joint action planning in chimpanzees reflects similar patterns to humans. Chimpanzees' chosen handover locations shifted towards the location of the experimenter's free or unobstructed hand, suggesting they represent the constraints of the joint task even though their individual half of the task was unobstructed. These findings indicate that chimpanzees and humans may share common cognitive mechanisms or predispositions that support joint action.

Talk to the Wall: The Role of Speech Interaction in Collaborative Visual Analytics.

We present the results of an exploratory study on how pairs interact with speech commands and touch gestures on a wall-sized display during a collaborative sensemaking task. Previous work has shown that speech commands, alone or in combination with other input modalities, can support visual data exploration by individuals. However, it is still unknown whether and how speech commands can be used in collaboration, and for what tasks. To answer these questions, we developed a functioning prototype that we used as a technology probe. We conducted an in-depth exploratory study with 10 participant pairs to analyze their interaction choices, the interplay between the input modalities, and their collaboration. While touch was the most used modality, we found that participants preferred speech commands for global operations, used them for distant interaction, and that speech interaction contributed to the awareness of the partner's actions. Furthermore, the likelihood of using speech commands during collaboration was related to the personality trait of agreeableness. Regarding collaboration styles, participants interacted with speech equally often whether they were in loosely or closely coupled collaboration. While the partners stood closer to each other during close collaboration, they did not distance themselves to use speech commands. From our fndings, we derive and contribute a set of design considerations for collaborative and multimodal interactive data analysis systems. All supplemental materials are available at https://osf.io/8gpv2.

The Impact of Stiffness in Bimanual Versus Dyadic Interactions Requiring Force Exchange.

During daily activities, humans routinely manipulate objects bimanually or with the help of a partner. This work explored how bimanual and dyadic coordination modes are impacted by the object's stiffness, which conditions inter-limb haptic communication. For this, we recruited 20 healthy participants who performed a virtual task inspired by object handling, where we looked at the initiation of force exchange and its continued maintenance while tracking. Our findings suggest that while individuals and dyads displayed different motor behaviours, which may stem from the dyad members' need to estimate their partner's actions, they exhibited similar tracking accuracy. For both coordination modes, increased stiffness resulted in better tracking accuracy and more correlated motions, but required a larger effort through increased average torque. These results suggest that stiffness may be a key consideration in applications such as rehabilitation, where bimanual or external physical assistance is often provided.

Cortico-cerebellar audio-motor regions coordinate self and other in musical joint action.

Joint music performance requires flexible sensorimotor coordination between self and other. Cognitive and sensory parameters of joint action-such as shared knowledge or temporal (a)synchrony-influence this coordination by shifting the balance between self-other segregation and integration. To investigate the neural bases of these parameters and their interaction during joint action, we asked pianists to play on an MR-compatible piano, in duet with a partner outside of the scanner room. Motor knowledge of the partner's musical part and the temporal compatibility of the partner's action feedback were manipulated. First, we found stronger activity and functional connectivity within cortico-cerebellar audio-motor networks when pianists had practiced their partner's part before. This indicates that they simulated and anticipated the auditory feedback of the partner by virtue of an internal model. Second, we observed stronger cerebellar activity and reduced behavioral adaptation when pianists encountered subtle asynchronies between these model-based anticipations and the perceived sensory outcome of (familiar) partner actions, indicating a shift towards self-other segregation. These combined findings demonstrate that cortico-cerebellar audio-motor networks link motor knowledge and other-produced sounds depending on cognitive and sensory factors of the joint performance, and play a crucial role in balancing self-other integration and segregation.

Midfrontal Theta Transcranial Alternating Current Stimulation Facilitates Motor Coordination in Dyadic Human-Avatar Interactions.

Synchronous interpersonal motor interactions require moment-to-moment prediction and proactive monitoring of the partner's actions. Neurophysiologically, this is highlighted by an enhancement of midfrontal theta (4-7 Hz) oscillations. In this study, we explored the causal role of midfrontal theta for interpersonal motor interactions using transcranial alternating current stimulation (tACS). We implemented a realistic human-avatar interaction task in immersive virtual reality where participants controlled a virtual arm and hand to press a button synchronously with a virtual partner. Participants completed the task while receiving EEG-informed theta (Experiment 1) or beta (control frequency, Experiment 2) tACS over the frontal midline, as well as sham stimulation as a control. Results showed that midfrontal theta tACS significantly improved behavioral performance (i.e., reduced interpersonal asynchrony) and participants' motor strategies (i.e., increased movement times and reduced RTs), whereas beta tACS had no effect on these measures. These results suggest that theta tACS over frontal areas facilitates action monitoring and motor abilities supporting interpersonal interactions.

The sense of agency in joint actions: A theory-driven meta-analysis

The sense of agency is the feeling of voluntarily controlling our actions and their effects. It represents a crucial component of self-awareness, and it is foundational to our perception of responsibility toward what we do as individuals acting in a social context. While the sense of agency has been widely investigated in individual contexts, much less is known about the agency experienced when subjects are involved in motor interactions, despite its relevance in the social domain. To fill this gap, here we review the literature on the sense of agency experienced during motor interactions. We aimed to test the reliability of this sense of joint agency across studies and define what features can modulate its explicit and implicit components. To this end, we performed a formal meta-analysis of studies investigating the implicit feeling of agency in joint actions and a systematic review of studies addressing explicit judgments of agency during motor interactions. Our review indicates that, during interactions, a sense of agency can also be experienced for the partner's actions, both at an implicit and explicit level, and that this possibility strongly depends on predictive sensorimotor mechanisms. Contextual cues play a crucial role too, but mainly on explicit agency judgments, while they do not affect the implicit feeling of agency. These results are discussed in light of current cognitive theories on motor awareness and motor interactions. We also propose a hierarchical model based on recursive predictive and comparative processes whereby the sense of joint agency is grounded on a weighted combination of sensorimotor and contextual cues. Finally, we discuss how this model may provide a framework for future research in the social and clinical domains.

Live agent preference and social action monitoring in the macaque mid-superior temporal sulcus region

Mentalizing, the ability to infer the mental states of others, is a cornerstone of adaptive social intelligence. While functional brain mapping of human mentalizing has progressed considerably, its evolutionary signature in nonhuman primates remains debated. The discovery that the middle part of the macaque superior temporal sulcus (mid-STS) region has a connectional fingerprint most similar to the human temporoparietal junction (TPJ)-a crucial node in the mentalizing network-raises the possibility that these cortical areas may also share basic functional properties associated with mentalizing. Here, we show that this is the case in aspects of a preference for live social interactions and in a theoretical framework of predictive coding. Macaque monkeys were trained to perform a turn-taking choice task with another real monkey partner sitting directly face-to-face or a filmed partner appearing in prerecorded videos. We found that about three-fourths of task-related mid-STS neurons exhibited agent-dependent activity, most responding selectively or preferentially to the partner's action. At the population level, activities of these partner-type neurons were significantly greater under live-partner compared to video-recorded-partner task conditions. Furthermore, a subset of the partner-type neurons responded proactively when predictions about the partner's action were violated. This prediction error coding was specific to the action domain; almost none of the neurons signaled error in the prediction of reward. The present findings highlight unique roles of the macaque mid-STS at the single-neuron level and further delineate its functional parallels with the human TPJ in social cognitive processes associated with mentalizing.

Individual vs. Social Learning: An Experiment

We study the effectiveness of social learning when subjects can also learn individually. In the baseline treatment, a subject observes a sequence of private signals about an unknown state of the world and chooses an action to match the state. In the unilateral social learning treatment, a subject observes the lagged actions of another subject in the baseline condition in addition to her own private signals. In the bilateral treatment, two subjects observe each other's lagged actions in addition to their own signals. While beliefs and decisions become more accurate over time, social learning fails in the sense that accuracy is not improved by observing another subject's actions. The median subject extracts 1.6% of the available information from her partner's action in the bilateral treatment and about 20% of the available information in the unilateral treatment. We also find evidence of correlation neglect: subjects in the bilateral treatment treat the actions of others as if they do not depend on their own past histories.

Learning to Communicate Implicitly by Actions

In situations where explicit communication is limited, human collaborators act by learning to: (i) infer meaning behind their partner's actions, and (ii) convey private information about the state to their partner implicitly through actions. The first component of this learning process has been well-studied in multi-agent systems, whereas the second — which is equally crucial for successful collaboration — has not. To mimic both components mentioned above, thereby completing the learning process, we introduce a novel algorithm: Policy Belief Learning (PBL). PBL uses a belief module to model the other agent's private information and a policy module to form a distribution over actions informed by the belief module. Furthermore, to encourage communication by actions, we propose a novel auxiliary reward which incentivizes one agent to help its partner to make correct inferences about its private information. The auxiliary reward for communication is integrated into the learning of the policy module. We evaluate our approach on a set of environments including a matrix game, particle environment and the non-competitive bidding problem from contract bridge. We show empirically that this auxiliary reward is effective and easy to generalize. These results demonstrate that our PBL algorithm can produce strong pairs of agents in collaborative games where explicit communication is disabled.

Self-presentation work of people experiencing homelessness. Mixed social situations background

The article is a reflection on the participatory research conducted by me among the homeless living in the streets of a large city outside the system of institutional aid (2005–2008) and in the environment of homeless people staying in the hostel created within the framework of one of the associations (from 2007 to 2013). The location of these studies within the interpretative orientation ensures an opportunity to get to know the perspective of the Respondents (in this particular case – the homeless). Work on self-presentation is based on the assumption of symbolic interactionism, according to which the basis of interaction is defining the situation, proceeding through interpretation, so reading the meaning of the partner's action and definition, informing the partner about the intentions of action. Therefore, work on self-presentation is an attempt to read the meaning of a partner's activity, based on a specific way of imagining a partner, and thus – the way of treating him and the mechanisms accompanying work on self-presentation.

Midline frontal and occipito-temporal activity during error monitoring in dyadic motor interactions

Discrepancies between sensory predictions and action outcome are at the base of error coding. However, these phenomena have mainly been studied focussing on individual performance. Here, we explored EEG responses to motor prediction errors during a human-avatar interaction and show that Theta/Alpha activity of the frontal error-monitoring system works in phase with activity of the occipito-temporal node of the action observation network. Our motor interaction paradigm required healthy individuals to synchronize their reach-to-grasp movements with those of a virtual partner in conditions that did (Interactive) or did not require (Cued) movement prediction and adaptation to the partner's actions. Crucially, in 30% of the trials the virtual partner suddenly and unpredictably changed its movement trajectory thereby violating the human participant's expectation. These changes elicited error-related neuromarkers (ERN/Pe - Theta/Alpha modulations) over fronto-central electrodes during the Interactive condition. Source localization and connectivity analyses showed that the frontal Theta/Alpha activity induced by violations of the expected interactive movements was in phase with occipito-temporal Theta/Alpha activity. These results expand current knowledge about the neural correlates of on-line interpersonal motor interactions linking the frontal error-monitoring system to visual, body motion-related, responses.

Paying attention pays off: Kea improve in loose‐string cooperation by attending to partner

AbstractPrevious studies showed that kea are able to cooperate in experiments based on the loose‐string paradigm, but success rates were low, except when tested in stable dyads. We trained kea with low success rates to attend to the handling of the string by a human partner. This vastly improved subsequent coordination during cooperation with kea partners. Furthermore, we tested the kea dyads with a delayed entry set‐up (delays of 2, 4 or 6 s) and with two different lengths of string. Increasing length of delay and reducing string length had negative effects on the success rate. This suggests that a complete understanding of the actions was not present as the kea were not able to fully overcome factors that inhibit coordination. Lastly, we tested the three subjects showing the greatest ability to wait for the partner in a partner‐choice paradigm: one subject in the central position could pull a loose string with one partner after another in the order it preferred. As a result, the second subjects had much longer waiting times than previously experienced. We could show that the central kea learned to visit both set‐ups and that the second partner was able to wait for the partner to arrive before attempting to pull on the string, averaging twice as long as in the standard delay. Taken together, the results from this study highlight that cooperation in the loose‐string paradigm is largely dependent on coordination of the subjects. While attention to the partner's actions greatly improved performance, the greater waiting times achieved in the final set‐up also suggest that utilizing more ecologically relevant (subject is busy VS subject is held back) delays could further improve the performance of non‐human subjects in the delayed loose‐string paradigm.

Dyadic Interference Leads to Area of Uncertainty During Face-to-Face Cooperative Interception Task

People generally coordinate their action to be more efficient. However, in some cases, interference between them occur, resulting in an inefficient collaboration. For example, if two volleyball players collide while performing a serve reception, they can both miss the ball. The main goal of this study is to explore the way two persons regulate their actions when performing a cooperative task of ball interception, and how interference between them may occur. Starting face to face, twenty-four participants (twelve teams of two) had to physically intercept balls moving down from the roof to the floor of a virtual room. To this end, they controlled a virtual paddle attached to their hand moving along the anterior-posterior axis. No communication was allowed between participants so they had to focus on visual cues to decide if they should perform the interception or leave the partner do it. Participants were immersed in a stereoscopic virtual reality setup that allows the control of the situation and the visual stimuli they perceived, such as ball trajectories and the information available on the partner's motion. Results globally showed participants were often able to intercept balls without collision by dividing the interception space in two equivalent parts. However, an area of uncertainty (where many trials were not intercepted) appeared in the center of the scene, highlighting the presence of interference between participants. The width of this area increased when the situation became more complex (facing a real partner and not a stationary one) and when less information was available (only the paddle and not the partner's avatar). Moreover, participants initiated their interception later when real partner was present and often interpreted balls starting above them as balls they should intercept, even when these balls were \textit{in fine} intercepted by their partner. Overall, results showed that team coordination here emerges from between-participants interactions and that interference between them depends on task complexity (uncertainty on partner's action and visual information available)

Social context hinders humans but not ravens in a short‐term memory task

AbstractUsing resources shared within a social group—either in a cooperative or a competitive way—requires keeping track of own and others’ actions, which, in turn, requires well‐developed short‐term memory. Although short‐term memory has been tested in social mammal species, little is known about this capacity in highly social birds, such as ravens. We compared ravens (Corvus corax) with humans in spatial tasks based on caching, which required short‐term memory of one's own and of others’ actions. Human short‐term memory has been most extensively tested of all social mammal species, hence providing an informative benchmark for the ravens. A recent study on another corvid species (Corvus corone) suggests their capacity to be similar to the humans’, but short‐term memory skills have, to date, not been compared in a social setting. We used spatial setups based on caches of foods or objects, divided into individual and social conditions with two different spatial arrangements of caches (in a row or a 3 × 3 matrix). In each trial, a set of three up to nine caches was presented to an individual that was thereafter allowed to retrieve all items. Humans performed better on average across trials, but their performance dropped, when they had to keep track of partner's actions. This differed in ravens, as keeping track of such actions did not impair their performance. However, both humans and ravens demonstrated more memory‐related mistakes in the social than in the individual conditions. Therefore, whereas both the ravens’ and the humans’ memory suffered in the social conditions, the ravens seemed to deal better with the demands of these conditions. The social conditions had a competitive element, and one might speculate that ravens’ memory strategies are more attuned to such situations, in particular in caching contexts, than is the case for humans.

Communicative Competence: Responding to Residents’ Health Changes in Assisted Living

Frail and disabled individuals, including assisted living (AL) residents, are embedded in care convoys composed of dynamic networks of formal and informal care partners. Yet, little is known about how care convoys operate over time, especially when health changes occur. Thus, our aim was to provide an in-depth understanding of care convoy communication during times of residents' health changes in AL. Data for this analysis come from a Grounded Theory study that involved 50 residents and their care convoy members (n = 169) from 8 diverse AL communities followed over 2 years. Researchers conducted formal and informal interviewing, participant observation, and record review. We identified "communicative competence" as an explanatory framework in reference to a resident's or care partner's ability, knowledge, and action pertaining to communication and health change. Individual and collective competencies were consequential to timely and appropriate care. Communication involved: identifying; assessing significance; informing, consulting or collaborating with others; and responding to the change. Variability in communication process and properties (e.g., pace and timing; sequencing, timing, content, and mode of communication) depended on multiple factors, including the nature of the change and resident, informal and formal caregiver, convoy, AL community, and regulatory influences. Formal and informal care partners need support to establish, enhance, and maintain communicative competence in response to health changes. Findings reinforce the need for timely communication, effective systems, and well-documented accessible health care directives and have implications that are applicable to AL and other care settings.

The social Simon effect in the tactile sensory modality: a negative finding.

This study seeks to investigate whether users activate cognitive representations of their partner's action when they are involved in tactile collaborative tasks. The social Simon effect is a spatial stimulus-response interference induced by the mere presence of a partner in a go/nogo task. It has been extensively studied in the visual and auditory sensory modalities, but never before in the tactile modality. We compared the performances of 28 participants in three tasks: (1) a standard Simon task where participants responded to two different tactile stimuli applied to their fingertips with either their left or right foot, (2) an individual go/nogo task where participants responded to only one stimulus and (3) a social go/nogo task where they again responded to only one stimulus, but were partnered with another person who responded to the complementary stimulus. The interference effect due to spatial incongruence between the side where participants received the stimulus and the foot used to answer increased significantly in the standard Simon task compared to the social go/nogo task. Such a difference was not observed between the social and individual go/nogo tasks. Performances were nevertheless enhanced in the social go/nogo task, but irrespectively of the stimulus-response congruency. This study is the first to report a negative result for the social Simon effect in the tactile modality. Results suggest that cognitive representation of the co-actor is weaker in this modality.

Interactor's body shape does not affect visuo-motor interference effects during motor coordination

The biological-tuning of the Action Observation Network is highly debated. A current open question relates to whether the morphological appearance (body shape) and/or the biological motion of the observed agent triggers action simulation processes. Motor simulation of the partner's action is critical for motor interactions, where two partners coordinate their actions in space and time. It supports interpersonal alignment and facilitates online coordination. However, motor simulation also leads to visuo-motor interference effects when people are required to coordinate with complementary actions, i.e. incongruent movements as compared to the observed ones. Movement kinematics of interactive partners allows us to capture their automatic tendency to simulate and imitate the partner's complementary movements. In an online reach-to-grasp task, we investigated whether visuo-motor interference effects, visible in the kinematics of complementary movements, are modulated by the visual presence of the interactor's body shape. We asked participants to interact with 1) a humanoid agent with a human-like body shape and with real human, biological, movement kinematics, or 2) a non-humanoid agent, which did not resemble the human body-shape but moved with the same real kinematics. Through the combination of inferential and Bayesian statistics, the results show no effect of interactor's body shape on visuo-motor interference in reaching and grasping kinematics during online motor coordination. We discuss the results and propose that the kinematics of the observed movements, during motor interactions, might be the key factor for visuo-motor interference to take place independently from the morphological appearance of the partner. This is particularly relevant in a technological society that constantly asks humans to interact with artificial agents.