Joint action partners modulate the first step of an action sequence to communicate a distal goal.

When two co-actors perform a joint action, they often communicatively modulate their instrumental actions so as to facilitate each other's predictions of their immediate, proximal goals. Here, we ask whether co-actors would also engage in such "sensorimotor communication" for distal goals, specifically those that result from a two-step action sequence. To address this question, we asked pairs of participants to work together to deliver an animated box to one of two delivery locations displayed on a computer screen.

Communicative modulations of early action components support the prediction of distal goals.

The successful unfolding of many social interactions relies on our capacity to predict other people's action goals, whether these are proximal (i.e., immediate) or distal (i.

Me or we? Action-outcome learning in synchronous joint action.

Goal-directed behaviour requires mental representations that encode instrumental relationships between actions and their outcomes. The present study investigated how people acquire representations of joint actions where co-actors perform synchronized action contributions to produce joint outcomes in the environment. Adapting an experimental procedure to assess individual action-outcome learning, we tested whether co-acting individuals link jointly produced action outcomes to individual-level features of their own action contributions or to group-level features of their joint action instead.

Better Together: 14-Month-Old Infants Expect Agents to Cooperate.

Humans engage in cooperative activities from early on and the breadth of human cooperation is unparalleled. Human preference for cooperation might reflect cognitive and motivational mechanisms that drive engagement in cooperative activities. Here we investigate early indices of humans' cooperative abilities and test whether 14-month-old infants expect agents to prefer cooperative over individual goal achievement.

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.

Videos posted on the internet provide evidence for joint rushing in naturalistic social interactions.

When people engage in rhythmic joint actions, they unintentionally increase their tempo. However, this phenomenon of joint rushing has so far been investigated only under very specific and somewhat artificial conditions. Therefore, it remains unclear whether joint rushing generalizes to other instances of rhythmic joint action.

Understanding others' distal goals from proximal communicative actions.

Many social interactions require individuals to coordinate their actions and to inform each other about their goals. Often these goals concern an immediate (i.e.

Expert pianists make specific exaggerations for teaching.

Experts modulate their performance of actions for teaching purposes, performing slower and exaggerated movements when demonstrating novel actions to novices. The present study asked whether such modulations also occur during teaching performance of a music instrument, where subtle movement modulations are crucial for achieving artistic expression. While exaggerating performances of goal-directed actions outside of artistic contexts may be straightforward, it is an open question whether and how exaggeration for the purpose of teaching operates for actions that are expressive even when performed outside of a teaching context.

The role of reciprocity in dynamic interpersonal coordination of physiological rhythms.

A central question in social cognition research is how people coordinate their bodily rhythms, and how important reciprocity of interaction is for interpersonal coordination. Previous research has primarily focused on interpersonal action coordination, which has been shown to be facilitated by mechanisms of prediction and mutual adaption. Recent research is beginning to show that people also coordinate their physiological rhythms (i.

Inter-individual coordination in walking chimpanzees.

Humans, like many other animals, live in groups and coordinate actions with others in social settings. Such interpersonal coordination may emerge unconsciously and when the goal is not the coordination of movements, as when falling into the same rhythm when walking together. Although one of our closest living relatives, the chimpanzee (Pan troglodytes), shows the ability to succeed in complex joint action tasks where coordination is the goal, little is known about simpler forms of joint action.

Human adults prefer to cooperate even when it is costly.

Joint actions are cooperative activities where humans coordinate their actions to achieve individual and shared goals. While the motivation to engage in joint action is clear when a goal cannot be achieved by individuals alone, we asked whether humans are motivated to act together even when acting together is not necessary and implies incurring additional costs compared to individual goal achievement. Using a utility-based empirical approach, we investigated the extent of humans' preference for joint action over individual action, when the instrumental costs of performing joint actions outweigh the benefits.

Joint rushing alters internal timekeeping in non-musicians and musicians.

Recent studies have shown that people engaging in joint rhythmic activity unintentionally increase their tempo. The same tempo increase does not occur when the same rhythmic activity is performed alone. This phenomenon is known as joint rushing.

Evaluating the relative contributions of copying and reconstruction processes in cultural transmission episodes.

The ability to transmit information between individuals through social learning is a foundational component of cultural evolution. However, how this transmission occurs is still debated. On the one hand, the copying account draws parallels with biological mechanisms for genetic inheritance, arguing that learners copy what they observe and novel variations occur through random copying errors.

Crossmodal correspondences as common ground for joint action.

When performing joint actions, people rely on common ground - shared information that provides the required basis for mutual understanding. Common ground can be based on people's interaction history or on knowledge and expectations people share, e.g.

Affective compatibility with the self modulates the self-prioritisation effect.

The "self" shapes the way in which we process the world around us. It makes sense then, that self-related information is reliably prioritised over non self-related information in cognition. How might other factors such as self-compatibility shape the way self-relevant information is prioritised? The present work asks whether affective consistency between the self and arbitrarily self-associated stimuli influences the degree to which self-prioritisation can be observed.

How does a partner's motor variability affect joint action?

Motor learning studies demonstrate that an individual's natural motor variability predicts the rate at which she learns a motor task. Individuals exhibiting higher variability learn motor tasks faster, presumably because variability fosters exploration of a wider space of motor parameters. However, it is unclear how individuals regulate variability while learning a motor task together with a partner who perturbs their movements.

Motor constraints influence cultural evolution of rhythm.

While widely acknowledged in the cultural evolution literature, ecological factors-aspects of the physical environment that affect the way in which cultural productions evolve-have not been investigated experimentally. Here, we present an experimental investigation of this type of factor by using a transmission chain (iterated learning) experiment. We predicted that differences in the distance between identical tools (drums) and in the order in which they are to be used would cause the evolution of different rhythms.

Making sense of human interaction benefits from communicative cues.

We investigated whether communicative cues help observers to make sense of human interaction. We recorded EEG from an observer monitoring two individuals who were occasionally communicating with each other via either mutual eye contact and/or pointing gestures, and then jointly attending to the same object or attending to different objects that were placed on a table in front of them. The analyses were focussed on the processing of the interaction outcome (i.

Synchronicities that shape the perception of joint action.

In joint performances spanning from jazz improvisation to soccer, expert performers synchronize their movements in ways that novices cannot. Particularly, experts can align the velocity profiles of their movements in order to achieve synchrony on a fine-grained time scale, compared to novices who can only synchronize the duration of their movement intervals. This study investigated how experts' ability to engage in velocity-based synchrony affects observers' perception of coordination and their aesthetic experience of joint performances.

Sticking together? Re-binding previous other-associated stimuli interferes with self-verification but not partner-verification.

The self-prioritisation and we-prioritisation effects can be observed through faster responses to self-stimuli (self and group) than non-self-stimuli. It remains uncertain if we-prioritisation extends to individual members of one's own group. In light of recent work that implicates memory-based processes in identity-prioritisation effects, the present experiment was developed to determine whether a task-partner's identity relevant information also benefits from an enhanced representation, despite conflicting evidence of partner-prioritisation.

The sound of silence: an EEG study of how musicians time pauses in individual and joint music performance.

Pauses are an integral feature of social interaction. Conversation partners often pause between conversational turns, and musical co-performers often pause between musical phrases. How do humans coordinate the duration of pauses to ensure seamless interaction? A total of 40 trained pianists performed a simple melody containing fermatas (notated expressive pauses of unspecified duration) first alone (Solo) and then with a partner (Duet) while electroencephalography (EEG) was recorded.

Adaptation to unstable coordination patterns in individual and joint actions.

Previous research on interlimb coordination has shown that some coordination patterns are more stable than others, and function as attractors in the space of possible phase relations between different rhythmic movements. The canonical coordination patterns, i.e.

The engaging nature of interactive gestures.

The social interactions that we experience from early infancy often involve actions that are not strictly instrumental but engage the recipient by eliciting a (complementary) response. Interactive gestures may have privileged access to our perceptual and motor systems either because of their intrinsically engaging nature or as a result of extensive social learning. We compared these two hypotheses in a series of behavioral experiments by presenting individuals with interactive gestures that call for motor responses to complement the interaction ('hand shaking', 'requesting', 'high-five') and with communicative gestures that are equally socially relevant and salient, but do not strictly require a response from the recipient ('Ok', 'Thumbs up', 'Peace').

It goes with the territory: Ownership across spatial boundaries.

Previous studies have shown that people are faster to process objects that they own as compared with objects that other people own. Yet object ownership is embedded within a social environment that has distinct and sometimes competing rules for interaction. Here we ask whether ownership of space can act as a filter through which we process what belongs to us.