Previous research has demonstrated that people’s movements can become unintentionally coordinated during interpersonal interaction. The current study sought to uncover the degree to which visual and verbal (conversation) interaction constrains and organizes the rhythmic limb movements of coactors. Two experiments were conducted in which pairs of participants completed an interpersonal puzzle task while swinging handheld pendulums with instructions that minimized intentional coordination but facilitated either visual or verbal interaction. Cross-spectral analysis revealed a higher degree of coordination for conditions in which the pairs were visually coupled. In contrast, verbal interaction alone was not found to provide a sufficient medium for unintentional coordination to occur, nor did it enhance the unintentional coordination that emerged during visual interaction. The results raise questions concerning differences between visual and verbal informational linkages during interaction and how these differences may affect interpersonal movement production and its coordination. Interpersonal interaction often results in the movements of two interactants being coordinated. The dyadically defined goals that intentionally constrain interpersonal interaction are typically responsible for the emergence of this coordination. For instance,

Cooperative conversation has been shown to foster interpersonal postural coordination. The authors investigated whether such coordination is mediated by the influence of articulation on postural sway. In Experiment 1, talkers produced words in synchrony or in alternation, as the authors varied speaking rate and word similarity. Greater shared postural activity was found for the faster speaking rate. In Experiment 2, the authors demonstrated that shared postural activity also increases when individuals speak the same words or speak words that have similar stress patterns. However, this increase in shared postural activity is present only when participants ’ data are compared with those of their partner, who was present during the task, but not when compared with the data of a member of a different pair speaking the same word sequences as those of the original partner. The authors ’ findings suggest that interpersonal postural coordination observed during conversation is mediated by convergent speaking patterns.

The current study investigated the perception of intrapersonal, interpersonal, and tool-based grasping possibilities. In Experiment 1, participants judged whether they would grasp planks of wood—presented in ascending, descending, and random orders of length—using one hand (1H), two hands (2H), or with a tool that extended their reach (TH). In Experiment 2, participants physically grasped the planks using 1H, 2H, or TH. In Experiments 3 and 4, the choice of TH was replaced with a choice of grasping the planks with another person (2P). The results showed that presentation order influenced the participants’ behavior differently in the judgment and action experiments. The same behavioral patterns, however, were observed when participants switched between 1H and 2H, 2H and TH, and 2H and 2P grasping. The point at which participants judged they would switch between the different modes of grasping, as well as the point at which participants physically switched between the grasping modes, occurred at similar action-scaled ratios. The equivalence of perceiving intrapersonal and interpersonal affordances is discussed.

A major goal of cognitive and psychological science is to understand the systematic and coordinated patterns of everyday behavior. Whether we are trying to understand the coordinated actions that characterize behaviors like locomotion, reaching or grasping, or the perceptions of environmental objects, surfaces, or events, understanding the regularity of behavior, its flexibility and stability, the conditions under which it does or does not occur, and the processes or mechanisms by which it comes to be, calls for explanation—to determine causality. Traditionally, cognitive and psychological scientists have sought to confine the causality of all behavior by looking inward and thus reducing the system of interest to the mind or brain. In doing so, much of cognitive and psychological science has become exceedingly egocentric in focus, attempting to understand human perceiving and acting by isolating the centralized mental, computational, or representational processes that might account for it. Thus, the context of agency, of mind, and that which surrounds it and gives it material being, has been largely ignored. This is not only true for the activity of individuals, but also for the many joint or social actions that individuals engage in each day, such as when two or more people are moving furniture together, rowing a canoe, or simply walking and talking. Indeed, traditional explanations of interpersonal and social action are not only centered on the mental processes of mind and brain, but on the distinct

and unintentional interpersonal coordination

This thesis addresses the problem of robots navigating in populated environments. Because traditional obstacle-avoidance algorithms do not differentiate between people and other objects in the environment, this thesis argues that such methods do not produce socially acceptable results. Rather, robots must detect people in the environment and obey the social conventions that people use when moving around each other, such as tending to the right side of a hallway and respecting the personal space of others. By moving in a human-like manner, a robot will cause its actions to be easily understood and appear predictable to people, which will facilitate its ability to interact with people and thus to complete its tasks. We are interested in general spatial social tasks, such as navigating through a crowded hallway, as well as more cooperative tasks, such as accompanying a person side-by-side. We propose a novel framework for representing such tasks as a series of navigational constraints. In particular, we argue that each of the following must be considered at the navigational level: the task definition, societal conventions, and efficiency optimization. This thesis provides a theoretical basis for each of these categories. We propose to validate this conceptual framework by using it to design a simple navigational algorithm that will allow a robot to move through a populated environment while observing social conventions. We will then extend this algorithm within the framework to allow a robot to escort a person side-by-side. Finally, we will examine

physics of symbols. Springer.