Analysis of movement quality in full-body physical activities

Full-body human movement is characterized by fine-grain expressive qualities that humans are easily capable of exhibiting and recognizing in others' movement. In sports (e.g., martial arts) and performing arts (e.g., dance), the same sequence of movements can be performed in a wide range of ways characterized by different qualities, often in terms of subtle (spatial and temporal) perturbations of the movement. Even a non-expert observer can distinguish between a top-level and average performance by a dancer or martial artist. The difference is not in the performed movements-the same in both cases-but in the \u201cquality\u201d of their performance. In this article, we present a computational framework aimed at an automated approximate measure of movement quality in full-body physical activities. Starting from motion capture data, the framework computes low-level (e.g., a limb velocity) and high-level (e.g., synchronization between different limbs) movement features. Then, this vector of features is integrated to compute a value aimed at providing a quantitative assessment of movement quality approximating the evaluation that an external expert observer would give of the same sequence of movements. Next, a system representing a concrete implementation of the framework is proposed. Karate is adopted as a testbed. We selected two different katas (i.e., detailed choreographies of movements in karate) characterized by different overall attitudes and expressions (aggressiveness, meditation), and we asked seven athletes, having various levels of experience and age, to perform them. Motion capture data were collected from the performances and were analyzed with the system. The results of the automated analysis were compared with the scores given by 14 karate experts who rated the same performances. Results show that the movement-quality scores computed by the system and the ratings given by the human observers are highly correlated (Pearson's correlations r = 0.84, p = 0.001 and r = 0.75, p = 0.005)

What Cognitive and Affective States Should Technology Monitor to Support Learning?

This paper discusses self-efficacy, curiosity, and reflectivity as cognitive and affective states that are critical to learning but are overlooked in the context of affect-aware technology for learning. This discussion sits within the opportunities offered by the weDRAW project aiming at an embodied approach to the design of technology to support exploration and learning of mathematical concepts. We first review existing literature to clarify how the three states facilitate learning and how, if not supported, they may instead hinder learning. We then review the literature to understand how bodily expressions communicate these states and how technology could be used to monitor them. We conclude by presenting initial movement cues currently explored in the context of weDRAW

Evaluating Movement Quality Through Intrapersonal Synchronization

We present a method to measure intrapersonal synchronization of movement from motion capture data, and we show that our method is effective in classifying the level of skills of athletes performing karate kata. Our method is based on detecting relevant peaks of acceleration of limbs (arms and legs) and measuring their synchronization. We run a multiscale analysis, based on topological persistence, to rank the importance of peaks of acceleration. The resulting impulse signals are processed next with a multievent class synchronization algorithm, in order to define an overall synchronization index that scores the level of intrapersonal synchronization with a single scalar value. We build a basic multiclass classifier, which uses just the means of indexes computed on the different classes in the training set. We make a statistical analysis and a cross validation of the classifier on real data. Performances by athletes from three levels of skill have been recorded, classified by experts, and used to test our method. Cross validation of the classifier is performed by leave-one-out and bootstrap resampling. Results show that our method can classify correctly with very high probability (beyond $ext99 ext$), while it succeeds on $ext100 ext$ of the data used in cross validation

The influence of yaw rotation on spatial navigation during development

Sensory cues enable navigation through space, as they inform us about movement properties, such as the amount of travelled distance and the heading direction. In this study, we focused on the ability to spatially update one's position when only proprioceptive and vestibular information is available. We aimed to investigate the effect of yaw rotation on path integration across development in the absence of visual feedback. To this end, we utilized the triangle completion task: participants were guided through two legs of a triangle and asked to close the shape by walking along its third imagined leg. To test the influence of yaw rotation across development, we tested children between 6 and 11 years old (y.o.) and adults on their perceptions of angles of different degrees. Our results demonstrated that the amount of turn while executing the angle influences performance at all ages, and in some aspects, also interacted with age. Indeed, whilst adults seemed to adjust their heading towards the end of their walked path, younger children took less advantage of this strategy. The amount of disorientation the path induced also affected participants' full maturational ability to spatially navigate with no visual feedback. Increasing induced disorientation required children to be older to reach adult-level performance. Overall, these results provide novel insights on the maturation of spatial navigation-related processes

Interpersonal entrainment in music performance: Theory, method and model

Interpersonal musical entrainment—temporal synchronization and coordination between individuals in musical contexts—is a ubiquitous phenomenon related to music’s social functions of promoting group bonding and cohesion. Mechanisms other than sensorimotor synchronization are rarely discussed, while little is known about cultural variability or about how and why entrainment has social effects. In order to close these gaps, we propose a new model that distinguishes between different components of interpersonal entrainment: sensorimotor synchronization—a largely automatic process manifested especially with rhythms based on periodicities in the 100–2000 ms timescale—and coordination, extending over longer timescales and more accessible to conscious control. We review the state of the art in measuring these processes, mostly from the perspective of action production, and in so doing present the first cross-cultural comparisons between interpersonal entrainment in natural musical performances, with an exploratory analysis that identifies factors that may influence interpersonal synchronization in music. Building on this analysis we advance hypotheses regarding the relationship of these features to neurophysiological, social, and cultural processes. We propose a model encompassing both synchronization and coordination processes and the relationship between them, the role of culturally shared knowledge, and of connections between entrainment and social processes