An Approach to Aligning Categorical and Continuous Time Series for Studying the Dynamics of Complex Human Behavior.

An emerging perspective on human cognition and performance sees it as a kind of self-organizing phenomenon involving dynamic coordination across the body, brain and environment. Measuring this coordination faces a major challenge. Time series obtained from such cognitive, behavioral, and physiological coordination are often complicated in terms of non-stationarity and non-linearity, and in terms of continuous vs. categorical scales. Researchers have proposed several analytical tools and frameworks. One method designed to overcome these complexities is recurrence quantification analysis, developed in the study of non-linear dynamics. It has been applied in various domains, including linguistic (categorical) data or motion (continuous) data. However, most previous studies have applied recurrence methods individually to categorical or continuous data. To understand how complex coordination works, an integration of these types of behavior is needed. We aimed to integrate these methods to investigate the relationship between language (categorical) and motion (continuous) directly. To do so, we added temporal information (a time stamp) to categorical data (i.e., language), and applied joint recurrence analysis methods to visualize and quantify speech-motion coordination coupling during a rap performance. We illustrate how new dynamic methods may capture this coordination in a small case-study design on this expert rap performance. We describe a case study suggesting this kind of dynamic analysis holds promise, and end by discussing the theoretical implications of studying complex performances of this kind as a dynamic, coordinated phenomenon.

Synchronization and Coordination of Art Performances in Highly Competitive Contexts: Battle Scenes of Expert Breakdancers.

In the performing arts, such as music and dance performances, people actively interact with each other and show their exciting performances. Some studies have proposed that this interaction is a social origin of the performing arts. Some have further investigated this phenomenon based on the synchronization and coordination theory. Though the majority of these studies have focused on the collaborative context, several genres of the performing arts, such as jazz sessions and breakdance battles, have a competitive context. Several studies have suggested that, in this competitive context, performers actively interact with each other and construct some correspondence. Moreover, a few recent studies focusing on competitive conversations, such as debates, have shown that, compared to people's interactions in collaborative conversations, people in competitive contexts frequently coordinate their behaviors in complicated ways. However, the interaction and coordination among performers in these competitive contexts have not been sufficiently investigated. Therefore, we investigated the coordination of expert breakdancers in battle scenes and measured their rhythmic movements using a motion capture system. We calculated the relative phase of the rhythmic movements between two dancers to investigate their coordination. The results showed that the dancers' rhythmic movements tended to synchronize in an anti-phase fashion, which means that there were similarities as well as differences between the two dancers' rhythmic movements. Furthermore, this pattern of coordination changed dynamically as time elapsed, from an in-phase synchronization or leader-follower relationships to an anti-phase synchronization and then leader-follower relationships.

Secondhand Smoke from a Veranda Spreading to Neighboring Households.

Secondhand smoke (SHS) caused by smoking on apartment verandas is a severe social problem in Japan. If someone smokes on a veranda, SHS drifts into other residents' rooms through their windows. Most non-smoking residents are annoyed by this, but they do not confront the person responsible. To study this situation, we burned cigarettes and measured the spread of SHS in terms of fine particle (PM2.5) concentrations. Cigarette smoke generated on a lower veranda spread to upper and horizontal neighboring verandas and into rooms through windows, reaching a maximum concentration of 139 µg/m3. The Health Promotion Act that was revised in 2018 and enacted in 2019-2020 requires all smokers to avoid producing SHS, even outdoors and at home. It is expected that combining the measurement of SHS from verandas to other verandas and rooms with the revised Health Promotion Act could create a national consensus on "no smoking on apartment verandas."

How Do Creative Experts Practice New Skills? Exploratory Practice in Breakdancers.

How do expert performers practice as they develop creatively? This study investigated the processes involved in the practice of new skills by expert breakdancers. A great deal of evidence supports the theory of "deliberate practice" (Ericsson, Krampe, & Tesch-Römer, 1993, Psychological Review, 100, 363) in skill acquisition; however, expert creative performers may emphasize other forms of practice for skill development. Four case studies collected through fieldwork and laboratory observation were analyzed to evaluate expert dancers' practice processes as they developed proficiency in new, specific skills. We focused on three aspects of learning: the degree of skill acquisition, the content of skills included in practice, and dancers' stated purposes for practicing. The results showed that dancers' practice improved skills (as suggested by deliberate practice) and engaged the exploration of new, original skills, along with coordinating skills within performance. In their practice, these dance experts went beyond deliberative practice to highly exploratory processes for skill development.

Host-Symbiont Cospeciation of Termite-Gut Cellulolytic Protists of the Genera Teranympha and Eucomonympha and their Treponema Endosymbionts.

Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (<97.1% and <91.9%, respectively). In addition, the endosymbionts of Teranympha spp. formed a phylogenetic clade distinct from those of Eucomonympha spp. Therefore, the endosymbiont species of Teranympha spp., designated here as "Candidatus Treponema teratonymphae", needs to be classified as a species distinct from the endosymbiont species of Eucomonympha spp.