April Karlinsky

Joint Action: Mental Representations, Shared Information and General Mechanisms for Coordinating with Others

In joint action, multiple people coordinate their actions to perform a task together. This often requires precise temporal and spatial coordination. How do co-actors achieve this? How do they coordinate their actions toward a shared task goal? Here, we provide an overview of the mental representations involved in joint action, discuss how co-actors share sensorimotor information and what general mechanisms support coordination with others. By deliberately extending the review to aspects such as the cultural context in which a joint action takes place, we pay tribute to the complex and variable nature of this social phenomenon.

Whose turn is it anyway? The moderating role of response-execution certainty on the joint Simon effect

When a two-choice “Simon task” is distributed between two people, performance in the shared go/no-go task resembles performance in the whole task alone. This finding has been described as the joint Simon effect (JSE). Unlike the individual go/no-go task, not only is the typical joint Simon task shared with another person, but also the imperative stimuli dictate whose turn it is to respond. Therefore, in the current study, we asked whether removing the agent discrimination component of the joint Simon task influences co-representation. Participants performed the typical joint Simon task, which was compared to two turn-taking versions of the task. For these turn-taking tasks, pairs predictably alternated turns on consecutive trials, with their respective imperative stimulus presented either on 100% of their turns (fully predictable group) or on 83% of their turns (response-uncertainty group, 17% no-go catch trials). The JSE was absent in the fully predictable, turn-taking task, but emerged similarly under the response-uncertainty condition and the typical joint Simon task condition where there is both turn and response-execution-related uncertainty. These results demonstrate that conflict related to agent discrimination is likely not a critical factor driving the JSE, whereas conflict surrounding the need to execute a response (and hence the degree of preparation) appears fundamental to co-representation.

Action-skilled observation: Issues for the study of sport expertise and the brain

With a growing body of research devoted to uncovering regions of the brain implicated in action observation following various action-related experiences, including sport, we ask what we know from this research, and what we still need to know, as it pertains to sport and the brain. To do this, we review and integrate knowledge garnered from developmental work, short-term motor learning studies, and most significantly sport athletes across varying skill levels. We consider various neurophysiological methods, including TMS, fMRI, and EEG, which have been used to help uncover brain regions involved in action-skilled observation. We are particularly interested in how these processes are related to action prediction and the detection of deceptive actions among athlete groups. This research is considered within broad theoretical frameworks related to action-simulation and prediction, although our main focus is on the brain regions that have been implicated in skilled action observation and the implications of this research for knowledge and further study of sport expertise.

Dyad Practice Impacts Self-Directed Practice Behaviors and Motor Learning Outcomes in a Contextual Interference Paradigm

ABSTRACT We studied dyad practice to determine whether and how alternating practice blocks with a partner impacts self-directed practice scheduling, learning, and perceptions of practice. Participants were assigned to be Partner 1 (P1) or 2 (P2). P1s had a blocked, random, or self-directed schedule, while all P2s self-directed practice of 3, differently-timed keystroke-sequences. P2s showed both own error-dependent practice (switching sequences following better performance) and partner-dependent practice, with the partners schedule impacting sequence selection and switching frequency. A partners schedule also impacted learning. Random practice resulted in better timing accuracy than blocked practice for both partners in an immediate and delayed retention test. These data give evidence that self-directed practice behaviors and learning outcomes are modulated by a partners practice schedule.

Let’s move it together: A review of group benefits in joint object control

In daily life, humans frequently engage in object-directed joint actions, be it carrying a table together or jointly pulling a rope. When two or more individuals control an object together, they may distribute control by performing complementary actions, e.g., when two people hold a table at opposite ends. Alternatively, several individuals may execute control in a redundant manner by performing the same actions, e.g., when jointly pulling a rope in the same direction. Previous research has investigated whether dyads can outperform individuals in tasks where control is either distributed or redundant. The aim of the present review is to integrate findings for these two types of joint control to determine common principles and explain differing results. In sum, we find that when control is distributed, individuals tend to outperform dyads or attain similar performance levels. For redundant control, conversely, dyads have been shown to outperform individuals. We suggest that these differences can be explained by the possibility to freely divide control: Having the option to exercise control redundantly allows co-actors to coordinate individual contributions in line with individual capabilities, enabling them to maximize the benefit of the available skills in the group. In contrast, this freedom to adopt and adapt customized coordination strategies is not available when the distribution of control is determined from the outset.