Dialog as interpersonal synergy

Interpersonal coordination in a ball-and-beam paradigm: Transfer of skill from solo action to joint action

Interpersonal coordination is paramount to the success of a joint action. While the pattern formation process of interpersonal coordination is relatively well understood, models like HKB lack an ecological dimension that relates the motor pattern to the environment. We investigated this dimension in a two-step study using the ball-and-beam paradigm. Participants rolled a ball back-and-forth between two targets on a beam, by manipulating the beam inclination either individually or dyadically. In an (earlier reported) first step, 16 participants performed two solo action sessions of the task, allowing us to identify pertinent performance characteristics. Here, those participants were paired into 8 dyads to perform a joint action session, allowing us to assess the solo-to-joint transfer of those characteristics. Over blocks, dyads improved their performance by increasing the ball speed and accuracy. While the relative variability of the beam's inclination angle decreased, the range and the timing of the beam motion remained unchanged. Variables (indirectly) related to ball speed, such as the range and timing of the beam motion, were strongly propagated from solo to joint action, while the variables related to ball accuracy, like the beam variability, were only moderately transferred. Most dyads established an anti-phase mode of coordination, with a significant decrease in phase variability over blocks. We also observed significant asymmetries in the coordination. Dyad members with a better solo-action performance were more likely to lead the interaction. We concluded that interpersonal coordination in the ball-and-beam paradigm emerged from the interaction, while being constrained by the goal of the task.

Abstractness impacts conversational dynamics

Conversation topics may vary in abstractness. This might impact the effort required by speakers to reach a common ground and, ultimately, an interactive alignment. In fact, people typically feel less confident with abstract concepts and single-words rating studies suggest abstract concepts are more associated with social interactions than concrete concepts-hence suggesting increasing levels of abstractness enhance inner and mutual monitoring processes. However, experimental studies addressing conversational dynamics afforded by abstract concepts are still sparse. In three preregistered experiments we ask whether abstract sentences are associated with specific constructs in dialogue, i.e., higher uncertainty, more curiosity and willingness to continue a conversation, and more questions related to causal and agency aspects. We do so by asking participants to evaluate the plausibility of linguistic exchanges referring to concrete and abstract concepts. Results support theories proposing that abstract concepts involve more inner monitoring and social dynamics compared to concrete concepts and suggest that reaching alignment in dialogue is more effortful with abstract than with concrete concepts.

Least Effort and Alignment in Task-Oriented Communication

Conversational partners align the meanings of their words over the course of interaction to coordinate and communicate. One process of alignment is lexical entrainment, whereby partners mirror and abbreviate their word usage to converge on shared terms for referents relevant to the conversation. However, lexical entrainment may result in inefficient mimicry that does not add new information, suggesting that task-oriented communication may favor alignment through other means. The present study investigates the process of alignment in Danish conversations in which dyads learned to categorize unfamiliar "aliens" using trial-and-error feedback. Performance improved as dyad communication became less verbose, measured as a decrease in the entropy of word usage. Word usage also diverged between partners as measured by Jensen-Shannon Divergence, which indicates that alignment was not achieved through lexical entrainment. A computational model of dyadic communication is shown to account for the alien game results in terms of joint least effort. The model shows that alignment of partner referents can increase as a result of minimizing both the joint entropy of dyadic word usage and the conditional entropy of individual referents given the joint signal distribution. We conclude that the principle of least effort, originally proposed to shape language evolution, may also support alignment in task-oriented communication.

Beyond Words: Speech Coordination Linked to Personality and Appraisals

We studied how personality differences and conversation topics predict interpersonal speech coordination, leading/following dynamics, and nonverbal interactional dominance in dyadic conversations. In a laboratory, 100 undergraduate students (50 same-gender dyads) had a 15-min conversation following three topics (introduction/self-disclosure/argumentation). Their speech coordination and turn-taking (speech/silence) dynamics were assessed through nonlinear time-series analyses: Cross-Recurrence Quantification Analysis (CRQA), Diagonal Cross-Recurrence Profiles (DCRP), and Anisotropic-CRQA. From the time series, we extracted five variables to operationalize speech coordination (global and at lag-zero), leading-following dynamics, and asymmetries in the interacting partners' nonverbal interactional dominance. Interaction appraisals were also assessed. Associations between personality traits Extraversion/Agreeableness, speech coordination, and nonverbal interactional dominance were tested using mixed-effects models. Speech coordination and nonverbal interactional dominance differed across conversational topics and peaked during argumentative conversations. Extraversion was associated with increased speech coordination, and nonverbal interactional dominance, especially during the argumentative conversation. During a self-disclosure conversation, Extraversion concordance was associated with more symmetry in turn-taking dynamics. Speech coordination was generally associated with positive post-conversational appraisals such as wanting to meet in the future or liking the conversation partner, especially in extroverted individuals, whereas introverts seemed to value less swift dynamics. High Agreeableness predicted less speech coordination during argumentative conversations, and increased speech coordination (at lag-zero) predicted reduced perceived naturality in agreeable individuals. This may suggest a trade-off between maintaining swift speech dynamics and the natural flow of conversation for individuals high in Agreeableness.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10919-025-00482-3.

Automatic and strategic components of bilingual lexical alignment

Second-language speakers are more likely to strategically reuse the words of their conversation partners (Zhang & Nicol, 2022). This study investigates if this is also the case for lower-proficiency bilinguals from a bilingual community, who use language more implicitly, and if there is more alignment with lower than with higher proficiency, provided the words to be aligned to are all highly familiar. In two experiments, Spanish-English bilinguals took turns with a confederate to name and match pictures in Spanish. The confederate named critical pictures with a dispreferred but acceptable name (e.g., agua [Sp. water] for a picture of rain). In Experiment 1, bilinguals were more likely to name critical pictures with dispreferred names after hearing these names from the confederate than after the confederate named an unrelated picture instead (i.e., an alignment effect). In support of our hypothesis, there was more alignment in lower-proficiency speakers. In Experiment 2, designed to reduce the possibility for strategic alignment, only confederates but not participants performed the matching task, which precluded participants from linking the dispreferred names with a referent, and removed the incentive to pay attention to the confederate's names. As a result, alignment was reduced (though still present). Of most interest, the reduction was greater for lower-proficiency speakers, supporting the hypothesis that strategic lexical-referential alignment is more likely with lower proficiency even for bilinguals from a bilingual community. The study also isolates measurable strategic and automatic components of lexical-referential alignment.

Investigating Linguistic Alignment in Collaborative Dialogue: A Study of Syntactic and Lexical Patterns in Middle School Students

Linguistic alignment, the tendency of speakers to share common linguistic features during conversations, has emerged as a key area of research in computer-supported collaborative learning. While previous studies have shown that linguistic alignment can have a significant impact on collaborative outcomes, there is limited research exploring its role in K-12 learning contexts. This study investigates syntactic and lexical linguistic alignments in a collaborative computer science-learning corpus from 24 pairs (48 individuals) of middle school students (aged 11-13). The results show stronger effects of self-alignment than partner alignment on both syntactic and lexical levels, with students often diverging from their partners on task-relevant words. Furthermore, student self-alignment on the syntactic level is negatively correlated with partner satisfaction ratings, while self-alignment on lexical level is positively correlated with their partner's satisfaction.

Dyadic differences in empathy scores are associated with kinematic similarity during conversational question-answer pairs

During conversation, speakers coordinate and synergize their behaviors at multiple levels, and in different ways. The extent to which individuals converge or diverge in their behaviors during interaction may relate to interpersonal differences relevant to social interaction, such as empathy as measured by the empathy quotient (EQ). An association between interpersonal difference in empathy and interpersonal entrainment could help to throw light on how interlocutor characteristics influence interpersonal entrainment. We investigated this possibility in a corpus of unconstrained conversation between dyads. We used dynamic time warping to quantify entrainment between interlocutors of head motion, hand motion, and maximum speech f0 during question-response sequences. We additionally calculated interlocutor differences in EQ scores. We found that, for both head and hand motion, greater difference in EQ was associated with higher entrainment. Thus, we consider that people who are dissimilar in EQ may need to "ground" their interaction with low-level movement entrainment. There was no significant relationship between f0 entrainment and EQ score differences.

Distributional Semantics: Meaning Through Culture and Interaction

Mastering how to convey meanings using language is perhaps the main challenge facing any language learner. However, satisfactory accounts of how this is achieved, and even of what it is for a linguistic item to have meaning, are hard to come by. Nick Chater was one of the pioneers involved in the early development of one of the most successful methodologies within the cognitive science of language for discovering meaning: distributional semantics. In this article, we review this approach and discuss its successes and shortcomings in capturing semantic phenomena. In particular, we discuss what we dub the "distributional paradox:" how can models that do not implement essential dimensions of human semantic processing, such as sensorimotor grounding, capture so many meaning-related phenomena? We conclude by providing a preliminary answer, arguing that distributional models capture the statistical scaffolding of human language acquisition that allows for communication, which, in line with Nick Chater's more recent ideas, has been shaped by the features of human cognition on the timescale of cultural evolution.

Embodied hyperscanning for studying social interaction: A scoping review of simultaneous brain and body measurements

We systematically investigated the application of embodied hyperscanning methodologies in social neuroscience research. Hyperscanning enables the simultaneous recording of neurophysiological and physiological signals from multiple participants. We highlight the trend toward integrating Mobile Brain/Body Imaging (MoBI) within the 4E research framework, which emphasizes the interconnectedness of brain, body, and environment. Our analysis revealed a geographic concentration of studies in the Global North, calling for global collaboration and transcultural research to balance the field. The predominant use of Magneto/Electroencephalogram (M/EEG) in these studies suggests a traditional brain-centric perspective in social neuroscience. Future research directions should focus on integrating diverse techniques to capture the dynamic interplay between brain and body functions in real-world contexts. Our review also finds a preference for tasks involving natural settings. Nevertheless, the analysis in hyperscanning studies is often limited to physiological signal synchrony between participants. This suggests a need for more holistic and complex approaches that combine inter-corporeal synchrony with intra-individual measures. We believe that the future of the neuroscience of relationships lies in embracing the complexity of cognition, integrating diverse methods and theories to enrich our grasp of human social behavior in its natural contexts.

From unimodal to multimodal dynamics of verbal and nonverbal cues during unstructured conversation

Conversations encompass continuous exchanges of verbal and nonverbal information. Previous research has demonstrated that gestures dynamically entrain each other and that speakers tend to align their vocal properties. While gesture and speech are known to synchronize at the intrapersonal level, few studies have investigated the multimodal dynamics of gesture/speech between individuals. The present study aims to extend our comprehension of unimodal dynamics of speech and gesture to multimodal speech/gesture dynamics. We used an online dataset of 14 dyads engaged in unstructured conversation. Speech and gesture synchronization was measured with cross-wavelets at different timescales. Results supported previous research on intrapersonal speech/gesture coordination, finding synchronization at all timescales of the conversation. Extending the literature, we also found interpersonal synchronization between speech and gesture. Given that the unimodal and multimodal synchronization occurred at similar timescales, we suggest that synchronization likely depends on the vocal channel, particularly on the turn-taking dynamics of the conversation.

Prospects for Augmenting Team Interactions with Real-Time Coordination-Based Measures in Human-Autonomy Teams

Complex work in teams requires coordination across team members and their technology as well as the ability to change and adapt over time to achieve effective performance. To support such complex interactions, recent efforts have worked toward the design of adaptive human-autonomy teaming systems that can provide feedback in or near real time to achieve the desired individual or team results. However, while significant advancements have been made to better model and understand the dynamics of team interaction and its relationship with task performance, appropriate measures of team coordination and computational methods to detect changes in coordination have not yet been widely investigated. Having the capacity to measure coordination in real time is quite promising as it provides the opportunity to provide adaptive feedback that may influence and regulate teams' coordination patterns and, ultimately, drive effective team performance. A critical requirement to reach this potential is having the theoretical and empirical foundation from which to do so. Therefore, the first goal of the paper is to review approaches to coordination dynamics, identify current research gaps, and draw insights from other areas, such as social interaction, relationship science, and psychotherapy. The second goal is to collate extant work on feedback and advance ideas for adaptive feedback systems that have potential to influence coordination in a way that can enhance the effectiveness of team interactions. In addressing these two goals, this work lays the foundation as well as plans for the future of human-autonomy teams that augment team interactions using coordination-based measures.

Phonetic Dissimilarity and L2 Category Formation in L2 Accommodation

Many studies of speech accommodation focus on native speakers with different dialects, whereas only a limited number of studies work on L2 speakers' accommodation and discuss theories for second language (L2) accommodation. This paper aimed to fill the theoretical gap by integrating the revised speech learning model (SLM) with the exemplar-based models for L2 speech accommodation. A total of 19 Cantonese-English bilingual speakers completed map tasks with English speakers of Received Pronunciation and General American English in two separate experiments. Their pronunciations of THOUGHT and PATH vowels, and fricatives [z] and [θ] were examined before, during, and after the map tasks. The role of phonetic dissimilarity in L2 accommodation and L2 category formation in the revised SLM (SLM-r) were tested. First, the results suggested that global phonetic dissimilarity cannot predict Hong Kong English (HKE) speakers' accommodation patterns. Instead, the segment-specific phonetic dissimilarity between participants and interlocutors was found to be positively correlated with the participants' degree of accommodation. In addition, HKE speakers who did not form a new L2 category of [z] were found to significantly accommodate toward their interlocutor, suggesting that L2 accommodation might not be constrained by phonological category. An integrated exemplar model for L2 accommodation is proposed to explain these findings.

Mental state verb use in play by preschool-age children who stutter and their mothers

INTRODUCTION

Preschool-age children use mental state verbs (MSVs; e.g., think, know) to reference thoughts and other cognitive states. In play-based language, MSV use requires conversational flexibility, as speakers shift from discussion of actions happening in the here-and-now to more abstract discussion of mental states. Some evidence suggests that children who stutter (CWS) demonstrate subtle differences in shifting on experimental tasks of cognitive flexibility, differences which may extend to conversational flexibility. This study explored MSV use in conversational language between CWS and their mothers.

METHODS

Thirty-five preschool-age CWS and 35 age- and gender-matched children who do not stutter (CWNS), all performing within the typical range on standardized language testing, conversed with their mothers during play. Samples were transcribed and coded for MSV use.

RESULTS

No between-group differences were observed in MSV use, either between the CWS and CWNS or between the groups of mothers. Age and language skills were positively associated with MSV use in the CWNS group only. For both groups of dyads, mothers' MSV use corresponded at least to some extent to their children's language skills. Finally, correspondence between CWNS and their mothers was observed for two conversational language measures, representing lexical diversity and morphosyntax; this overall pattern was not observed in the CWS dyad group.

CONCLUSIONS

Although these findings point to similar use of MSVs among the groups of children and their mothers, for the CWS group, the patterns of use in relation to age and language skills are somewhat different from developmental expectations.

Conversational Speech Behaviors Are Context Dependent

PURPOSE

According to the interpersonal synergy model of spoken dialogue, interlocutors modify their communicative behaviors to meet the contextual demands of a given conversation. Although a growing body of research supports this postulation for linguistic behaviors (e.g., semantics, syntax), little is understood about how this model applies to speech behaviors (e.g., speech rate, pitch). The purpose of this study is to test the hypothesis that interlocutors adjust their speech behaviors across different conversational tasks with different conversational goals.

METHOD

In this study, 28 participants each engaged in two different types of conversations (i.e., relational and informational) with two partners (i.e., Partner 1 and Partner 2), yielding a total of 112 conversations. We compared six acoustic measures of participant speech behavior across conversational task and partner.

RESULTS

Linear mixed-effects models demonstrated significant differences between speech feature measures in informational and relational conversations. Furthermore, these findings were generally robust across conversations with different partners.

CONCLUSIONS

Results suggest that contextual demands influence speech behaviors. These findings provide empirical support for the interpersonal synergy model and highlight important considerations for assessing speech behaviors in individuals with communication disorders.

Lexical Alignment is Pervasive Across Contexts in Non-WEIRD Adult-Child Interactions

Lexical alignment, a communication phenomenon where conversational partners adapt their word choices to become more similar, plays an important role in the development of language and social communication skills. While this has been studied extensively in the conversations of preschool-aged children and their parents in Western, Educated, Industrialized, Rich, and Democratic (WEIRD) communities, research in other pediatric populations is sparse. This study makes significant expansions on the existing literature by focusing on alignment in naturalistic conversations of school-aged children from a non-WEIRD population across multiple conversational tasks and with different types of adult partners. Typically developing children aged 5 to 8 years (n = 45) engaged in four semi-structured conversations that differed by task (problem-solving vs. play-based) and by partner (parent vs. university student), resulting in a corpus of 180 conversations. Lexical alignment scores were calculated and compared to sham conversations, representing alignment occurring at the level of chance. Both children and adults coordinated their conversational utterances by re-using or aligning each other's word choices. This alignment behavior persisted across conversational tasks and partners, although the degree of alignment was moderated by the conversational context. These findings suggest that lexical alignment is a robust phenomenon in conversations between school-age children and adults. Furthermore, this study extends lexical alignment findings to a non-WEIRD culture, suggesting that alignment may be a coordination strategy employed by adults and children across diverse linguistic and cultural backgrounds.

Studying Conversational Adjustments in Interaction: Beyond Acoustic Phonetic Changes

PURPOSE

We examined which measures of complexity are most informative when studying language produced in interaction. Specifically, using these measures, we explored whether native and nonnative speakers modified the higher level properties of their production beyond the acoustic-phonetic level based on the language background of their conversation partner.

METHOD

Using a subset of production data from the Wildcat Corpus that used Diapix, an interactive picture matching task, to elicit production, we compared English language production at the dyad and individual level across three different pair types: eight native pairs (English-English), eight mixed pairs (four English-Chinese and four English-Korean), and eight nonnative pairs (four Chinese-Chinese and four Korean-Korean).

RESULTS

At both the dyad and individual levels, native speakers produced longer and more clausally dense speech. They also produced fewer silent pauses and fewer linguistic mazes relative to nonnative speakers. Speakers did not modify their production based on the language background of their interlocutor.

CONCLUSIONS

The current study examines higher level properties of language production in true interaction. Our results suggest that speakers' productions were determined by their own language background and were independent of that of their interlocutor. Furthermore, these demonstrated promise for capturing syntactic characteristics of language produced in true dialogue.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24712956.

Multi-Level Linguistic Alignment in a Dynamic Collaborative Problem-Solving Task

Cocreating meaning in collaboration is challenging. Success is often determined by people's abilities to coordinate their language to converge upon shared mental representations. Here we explore one set of low-level linguistic behaviors, linguistic alignment, that both emerges from, and facilitates, outcomes of high-level convergence. Linguistic alignment captures the ways people reuse, that is, "align to," the lexical, syntactic, and semantic forms of others' utterances. Our focus is on the temporal change of multi-level linguistic alignment, as well as how alignment is related to communicative outcomes within a unique collaborative problem-solving paradigm. The primary task, situated within a virtual educational video game, requires creative thinking between three people where the paths for possible solutions are highly variable. We find that over time interactions are marked by decreasing lexical and syntactic alignment, with a trade-off of increasing semantic alignment. However, greater semantic alignment does not translate into better team performance. Overall, these findings provide greater clarity on the role of linguistic coordination within complex and dynamic collaborative problem-solving tasks.

Behavioral dynamics of conversation, (mis)communication and coordination in noisy environments

During conversations people coordinate simultaneous channels of verbal and nonverbal information to hear and be heard. But the presence of background noise levels such as those found in cafes and restaurants can be a barrier to conversational success. Here, we used speech and motion-tracking to reveal the reciprocal processes people use to communicate in noisy environments. Conversations between twenty-two pairs of typical-hearing adults were elicited under different conditions of background noise, while standing or sitting around a table. With the onset of background noise, pairs rapidly adjusted their interpersonal distance and speech level, with the degree of initial change dependent on noise level and talker configuration. Following this transient phase, pairs settled into a sustaining phase in which reciprocal speech and movement-based coordination processes synergistically maintained effective communication, again with the magnitude of stability of these coordination processes covarying with noise level and talker configuration. Finally, as communication breakdowns increased at high noise levels, pairs exhibited resetting behaviors to help restore communication-decreasing interpersonal distance and/or increasing speech levels in response to communication breakdowns. Approximately 78 dB SPL defined a threshold where behavioral processes were no longer sufficient for maintaining effective conversation and communication breakdowns rapidly increased.

Measuring Prosodic Entrainment in Conversation: A Review and Comparison of Different Methods

PURPOSE

This study aims to further our understanding of prosodic entrainment and its different subtypes by analyzing a single corpus of conversations with 12 different methods and comparing the subsequent results.

METHOD

Entrainment on three fundamental frequency features was analyzed in a subset of recordings from the LUCID corpus (Baker & Hazan, 2011) using the following methods: global proximity, global convergence, local proximity, local convergence, local synchrony (Levitan & Hirschberg, 2011), prediction using linear mixed-effects models (Schweitzer & Lewandowski, 2013), geometric approach (Lehnert-LeHouillier, Terrazas, & Sandoval, 2020), time-aligned moving average (Kousidis et al., 2008), HYBRID method (De Looze et al., 2014), cross-recurrence quantification analysis (e.g., Fusaroli & Tylén, 2016), and windowed, lagged cross-correlation (Boker et al., 2002). We employed entrainment measures on a local timescale (i.e., on adjacent utterances), a global timescale (i.e., over larger time frames), and a time series-based timescale that is larger than adjacent utterances but smaller than entire conversations.

RESULTS

We observed variance in results of different methods.

CONCLUSIONS

Results suggest that each method may measure a slightly different type of entrainment. The complex implications this has for existing and future research are discussed.

Repeat After Me? Both Children With and Without Autism Commonly Align Their Language With That of Their Caregivers

Linguistic repetitions in children are conceptualized as negative in children with autism - echolalia, without communicative purpose - and positive in typically developing (TD) children - linguistic alignment involved in shared engagement, common ground and language acquisition. To investigate this apparent contradiction we analyzed spontaneous speech in 67 parent-child dyads from a longitudinal corpus (30 minutes of play activities at 6 visits over 2 years). We included 32 children with autism and 35 linguistically matched TD children (mean age at recruitment 32.76 and 20.27 months). We found a small number of exact repetitions in both groups (roughly 1% of utterances across visits), which increased over time in children with autism and decreased in the TD group. Partial repetitions were much more frequent: children reused caregivers' words at high rates regardless of diagnostic group (24% of utterances at first visit), and this increased in frequency (but not level) over time, faster for TD children (at final visit: 33% for autism, 40% for TD). The same happened for partial repetition of syntax and semantic alignment. However, chance alignment (as measured by surrogate pairs) also increased and findings for developmental changes were reliable only for syntactic and semantic alignment. Children with richer linguistic abilities also displayed a higher tendency to partially re-use their caregivers' language (alignment rates and semantic alignment). This highlights that all children commonly re-used the words, syntax, and topics of their caregivers, albeit with some quantitative differences, and that most repetition was at least potentially productive, with repeated language being re-contextualized and integrated with non-repeated language. The salience of echolalia in ASD might be partially explained by slight differences in frequency, amplified by lower semantic alignment, persistence over time, and expectations of echolalia. More in-depth qualitative and quantitative analyses of how repetitions are used and received in context are needed.

Language-Specific Constraints on Conversation: Evidence from Danish and Norwegian

Establishing and maintaining mutual understanding in everyday conversations is crucial. To do so, people employ a variety of conversational devices, such as backchannels, repair, and linguistic entrainment. Here, we explore whether the use of conversational devices might be influenced by cross-linguistic differences in the speakers' native language, comparing two matched languages-Danish and Norwegian-differing primarily in their sound structure, with Danish being more opaque, that is, less acoustically distinguished. Across systematically manipulated conversational contexts, we find that processes supporting mutual understanding in conversations vary with external constraints: across different contexts and, crucially, across languages. In accord with our predictions, linguistic entrainment was overall higher in Danish than in Norwegian, while backchannels and repairs presented a more nuanced pattern. These findings are compatible with the hypothesis that native speakers of Danish may compensate for its opaque sound structure by adopting a top-down strategy of building more conversational redundancy through entrainment, which also might reduce the need for repairs. These results suggest that linguistic differences might be met by systematic changes in language processing and use. This paves the way for further cross-linguistic investigations and critical assessment of the interplay between cultural and linguistic factors on the one hand and conversational dynamics on the other.

Scaffolding the human partner by contrastive guidance in an explanatory human-robot dialogue

Explanation has been identified as an important capability for AI-based systems, but research on systematic strategies for achieving understanding in interaction with such systems is still sparse. Negation is a linguistic strategy that is often used in explanations. It creates a contrast space between the affirmed and the negated item that enriches explaining processes with additional contextual information. While negation in human speech has been shown to lead to higher processing costs and worse task performance in terms of recall or action execution when used in isolation, it can decrease processing costs when used in context. So far, it has not been considered as a guiding strategy for explanations in human-robot interaction. We conducted an empirical study to investigate the use of negation as a guiding strategy in explanatory human-robot dialogue, in which a virtual robot explains tasks and possible actions to a human explainee to solve them in terms of gestures on a touchscreen. Our results show that negation vs. affirmation 1) increases processing costs measured as reaction time and 2) increases several aspects of task performance. While there was no significant effect of negation on the number of initially correctly executed gestures, we found a significantly lower number of attempts-measured as breaks in the finger movement data before the correct gesture was carried out-when being instructed through a negation. We further found that the gestures significantly resembled the presented prototype gesture more following an instruction with a negation as opposed to an affirmation. Also, the participants rated the benefit of contrastive vs. affirmative explanations significantly higher. Repeating the instructions decreased the effects of negation, yielding similar processing costs and task performance measures for negation and affirmation after several iterations. We discuss our results with respect to possible effects of negation on linguistic processing of explanations and limitations of our study.

(Mis)align: a simple dynamic framework for modeling interpersonal coordination

As people coordinate in daily interactions, they engage in different patterns of behavior to achieve successful outcomes. This includes both synchrony-the temporal coordination of the same behaviors at the same time-and complementarity-the coordination of the same or different behaviors that may occur at different relative times. Using computational methods, we develop a simple framework to describe the interpersonal dynamics of behavioral synchrony and complementarity over time, and explore their task-dependence. A key feature of this framework is the inclusion of a task context that mediates interactions, and consists of active, inactive, and inhibitory constraints on communication. Initial simulation results show that these task constraints can be a robust predictor of simulated agents' behaviors over time. We also show that the framework can reproduce some general patterns observed in human interaction data. We describe preliminary theoretical implications from these results, and relate them to broader proposals of synergistic self-organization in communication.

The Social Route to Abstraction: Interaction and Diversity Enhance Performance and Transfer in a Rule-Based Categorization Task

Capacities for abstract thinking and problem-solving are central to human cognition. Processes of abstraction allow the transfer of experiences and knowledge between contexts helping us make informed decisions in new or changing contexts. While we are often inclined to relate such reasoning capacities to individual minds and brains, they may in fact be contingent on human-specific modes of collaboration, dialogue, and shared attention. In an experimental study, we test the hypothesis that social interaction enhances cognitive processes of rule-induction, which in turn improves problem-solving performance. Through three sessions of increasing complexity, individuals and groups were presented with a problem-solving task requiring them to categorize a set of visual stimuli. To assess the character of participants' problem representations, after each training session, they were presented with a transfer task involving stimuli that differed in appearance, but shared relations among features with the training set. Besides, we compared participants' categorization behaviors to simulated agents relying on exemplar learning. We found that groups performed superior to individuals and agents in the training sessions and were more likely to correctly generalize their observations in the transfer phase, especially in the high complexity session, suggesting that groups more effectively induced underlying categorization rules from the stimuli than individuals and agents. Crucially, variation in performance among groups was predicted by semantic diversity in members' dialogical contributions, suggesting a link between social interaction, cognitive diversity, and abstraction.

A Methodological Framework to Study Change in Team Cognition Under the Dynamical Hypothesis

The dynamical hypothesis claims that cognitive systems, such as teams, are dynamical systems (i.e., an interdependent collection of individuals and their technology that change together over time). Following this hypothesis, team researchers have adopted dynamical approaches to better understand the team cognitive processes and states that form team cognition, as well as how they emerge over time. One approach focuses on team coordination dynamics, which examines the coupling of signals between interacting individuals in various modalities, and has been shown to reflect aspects of team functioning including team cognition. However, how changes in team coordination relate to high-level team cognitive processes and states, as well as important events, are not yet fully understood. To this end, we advance a methodological framework for researching team cognition under the dynamical hypothesis. Subsequently, we provided an empirical case-study application of this framework. Thereby, this work contributes methodologically and empirically to a deeper understanding of team cognition, the dynamical hypothesis, and the synergy between them.

Multifractal test for nonlinearity of interactions across scales in time series

The creativity and emergence of biological and psychological behavior tend to be nonlinear, and correspondingly, biological and psychological measures contain degrees of irregularity. The linear model might fail to reduce these measurements to a sum of independent random factors (yielding a stable mean for the measurement), implying nonlinear changes over time. The present work reviews some of the concepts implicated in nonlinear changes over time and details the mathematical steps involved in their identification. It introduces multifractality as a mathematical framework helpful in determining whether and to what degree the measured series exhibits nonlinear changes over time. These mathematical steps include multifractal analysis and surrogate data production for resolving when multifractality entails nonlinear changes over time. Ultimately, when measurements fail to fit the structures of the traditional linear model, multifractal modeling allows for making those nonlinear excursions explicit, that is, to come up with a quantitative estimate of how strongly events may interact across timescales. This estimate may serve some interests as merely a potentially statistically significant indicator of independence failing to hold, but we suspect that this estimate might serve more generally as a predictor of perceptuomotor or cognitive performance.

Caregiver linguistic alignment to autistic and typically developing children: A natural language processing approach illuminates the interactive components of language development

BACKGROUND

Language development is a highly interactive activity. However, most research on linguistic environment has focused on the quantity and complexity of linguistic input to children, with current models showing that complexity facilitates language in both typically developing (TD) and autistic children.

AIMS

After reviewing existing work on caregiver engagement of children's utterances, we aim to operationalize such engagement with automated measures of linguistic alignment, thereby providing scalable tools to assess caregivers' active reuse of their children's language. By assessing the presence of alignment, its sensitivity to the child's individual differences and how well it predicts language development beyond current models across the two groups, we showcase the usefulness of the approach and provide initial empirical foundations for further conceptual and empirical investigations.

METHODS

We measure lexical, syntactic and semantic types of caregiver alignment in a longitudinal corpus involving 32 adult-autistic child and 35 adult-TD child dyads, with children between 2 and 5 years of age. We assess the extent to which caregivers repeat their children's words, syntax, and semantics, and whether these repetitions predict language development beyond more standard predictors.

RESULTS

Caregivers tend to re-use their child's language in a way that is related to the child's individual, primarily linguistic, differences. Caregivers' alignment provides unique information improving our ability to predict future language development in both typical and autistic children.

CONCLUSIONS

We provide evidence that language development also relies on interactive conversational processes, previously understudied. We share carefully detailed methods, and open-source scripts so as to systematically extend our approach to new contexts and languages.

Postural and Gestural Synchronization, Sequential Imitation, and Mirroring Predict Perceived Coupling of Dancing Dyads

Body movement is a primary nonverbal communication channel in humans. Coordinated social behaviors, such as dancing together, encourage multifarious rhythmic and interpersonally coupled movements from which observers can extract socially and contextually relevant information. The investigation of relations between visual social perception and kinematic motor coupling is important for social cognition. Perceived coupling of dyads spontaneously dancing to pop music has been shown to be highly driven by the degree of frontal orientation between dancers. The perceptual salience of other aspects, including postural congruence, movement frequencies, time-delayed relations, and horizontal mirroring remains, however, uncertain. In a motion capture study, 90 participant dyads moved freely to 16 musical excerpts from eight musical genres, while their movements were recorded using optical motion capture. A total from 128 recordings from 8 dyads maximally facing each other were selected to generate silent 8-s animations. Three kinematic features describing simultaneous and sequential full body coupling were extracted from the dyads. In an online experiment, the animations were presented to 432 observers, who were asked to rate perceived similarity and interaction between dancers. We found dyadic kinematic coupling estimates to be higher than those obtained from surrogate estimates, providing evidence for a social dimension of entrainment in dance. Further, we observed links between perceived similarity and coupling of both slower simultaneous horizontal gestures and posture bounding volumes. Perceived interaction, on the other hand, was more related to coupling of faster simultaneous gestures and to sequential coupling. Also, dyads who were perceived as more coupled tended to mirror their pair's movements.

Cognitive Science Progresses Toward Interactive Frameworks

Despite its many twists and turns, the arc of cognitive science generally bends toward progress, thanks to its interdisciplinary nature. By glancing at the last few decades of experimental and computational advances, it can be argued that-far from failing to converge on a shared set of conceptual assumptions-the field is indeed making steady consensual progress toward what can broadly be referred to as interactive frameworks. This inclination is apparent in the subfields of psycholinguistics, visual perception, embodied cognition, extended cognition, neural networks, dynamical systems theory, and more. This pictorial essay briefly documents this steady progress both from a bird's eye view and from the trenches. The conclusion is one of optimism that cognitive science is getting there, albeit slowly and arduously, like any good science should.

On the social nature of abstraction: cognitive implications of interaction and diversity

The human capacity for abstraction is remarkable. We effortlessly form abstract representations from varied experiences, generalizing and flexibly transferring experiences and knowledge between contexts, which can facilitate reasoning, problem solving and learning across many domains. The cognitive process of abstraction, however, is often portrayed and investigated as an individual process. This paper addresses how cognitive processes of abstraction-together with other aspects of human reasoning and problem solving-are fundamentally shaped and modulated by online social interaction. Starting from a general distinction between convergent thinking, divergent thinking and processes of abstraction, we address how social interaction shapes information processing differently depending on cognitive demands, social coordination and task ecologies. In particular, we suggest that processes of abstraction are facilitated by the interactive sharing and integration of varied individual experiences. To this end, we also discuss how the dynamics of group interactions vary as a function of group composition; that is, in terms of the similarity and diversity between the group members. We conclude by outlining the role of cognitive diversity in interactive processes and consider the importance of group diversity in processes of abstraction. This article is part of the theme issue 'Concepts in interaction: social engagement and inner experiences'.

Editorial concepts in interaction: social engagement and inner experiences

This theme issue aims to view the literature on concepts through a novel lens, that of social interaction and its influence on inner experiences. It discusses unsolved problems in literature on concepts, emphasizing the distinction between concrete versus abstract concepts and external versus internal grounding. This introductory article reflects the two research streams that the theme aims to bridge-in this area, the dimension of embodied interaction with others and how this influences the interaction with ourselves is still underexplored. In the first part, we discuss recent trends in social cognition, showing how interacting with others influences our concepts. In the second part, we address how social interactions become part of our inner world in a Vygotskian fashion. First, we illustrate how interoception, emotion and metacognition are connected with concepts and knowledge. Second, we deal with how language, in both its outer and inner form, can empower cognition and concepts. We also briefly describe how novel experimental and computational methods contribute to investigating the online use of concepts. Overall, this introductory article outlines the potentialities of an integrated and interactive approach that can give new, fresh life to a topic, that of concepts, which lies at the root of human cognition. This article is part of the theme issue 'Concepts in interaction: social engagement and inner experiences'.

Social approach and avoidance in language: N400-like ERP negativity indexes congruency and theta rhythms the conflict

Motivational congruency has been examined using tasks where participants perform approach or avoidance movements towards socially positive or negative faces. Language is tightly intertwined with interpersonal cognition. Thus, similar situations could be represented by means of language in interpersonal contexts: adjectives furnish valence to people (e.g. someone is cordial or arrogant), and attitudinal verbs define direction to relationship-actions: approach-avoidance (e.g. accept vs. reject). In an Electroencephalography (EEG) study, 40 participants were presented with sentences where a character was valenced (e.g. "Arthur is cordial/arrogant") before being the target of a relationship-actions ("Grisela welcomed/ignored Arthur at the party"). We analyzed both Event-related potential (ERP) amplitude and time-frequency power in response to the attitudinal verb. For ERP amplitudes, we found a significant cluster between 280 and 370 ms, covering part of the development of a N400-like ERP component. This cluster reflects an interaction driven by congruency between motivational direction and target valence. Likewise, time-frequency power analysis revealed an enhancement of theta rhythms under incongruent conditions, most likely indexing conflict processing. Results support that relationship-actions are represented as approach and avoidance and thus involve conflict processing and resolution of incongruent situations. Implications for the interweaving of affective language and social cognition within Embodiment Simulation Theory are discussed.

Using video calls to study children's conversational development: The case of backchannel signaling

Understanding children's conversational skills is crucial for understanding their social, cognitive, and linguistic development, with important applications in health and education. To develop theories based on quantitative studies of conversational development, we need (i) data recorded in naturalistic contexts (e.g., child-caregiver dyads talking in their daily environment) where children are more likely to show much of their conversational competencies, as opposed to controlled laboratory contexts which typically involve talking to a stranger (e.g., the experimenter); (ii) data that allows for clear access to children's multimodal behavior in face-to-face conversations; and (iii) data whose acquisition method is cost-effective with the potential of being deployed at a large scale to capture individual and cultural variability. The current work is a first step to achieving this goal. We built a corpus of video chats involving children in middle childhood (6–12 years old) and their caregivers using a weakly structured word-guessing game to prompt spontaneous conversation. The manual annotations of these recordings have shown a similarity in the frequency distribution of multimodal communicative signals from both children and caregivers. As a case study, we capitalize on this rich behavioral data to study how verbal and non-verbal cues contribute to the children's conversational coordination. In particular, we looked at how children learn to engage in coordinated conversations, not only as speakers but also as listeners, by analyzing children's use of backchannel signaling (e.g., verbal “mh” or head nods) during these conversations. Contrary to results from previous in-lab studies, our use of a more spontaneous conversational setting (as well as more adequate controls) revealed that school-age children are strikingly close to adult-level mastery in many measures of backchanneling. Our work demonstrates the usefulness of recent technology in video calling for acquiring quality data that can be used for research on children's conversational development in the wild.

The social roots of self development: from a bodily to an intellectual interpersonal dialogue

In this paper, we propose that interpersonal bodily interactions represent a fertile ground in which the bodily and psychological self is developed, gradually allowing for forms of more abstract and disembodied interactions. We start by focusing on how early infant-caregiver bodily interactions play a crucial role in shaping the boundaries of the self but also in learning to predict others' behavior. We then explore the social function of the sense of touch in the entire life span, highlighting its role in promoting physical and psychological well-being by supporting positive interpersonal exchanges. We go on by introducing the concept of implicit theory of mind, as the early ability to interpret others' intentions, possibly grounded in infant-caregiver bodily exchanges (embodied practices). In the following part, we consider so-called higher level forms of social interaction: intellectual exchanges among individuals. In this regard, we defend the view that, beside the apparent private dimension of "thinking abstractly", using abstract concepts is intrinsically a social process, as it entails the re-enactment of the internalized dialogue through which we acquired the concepts in the first place. Finally, we describe how the hypothesis of "dialectical attunement" may explain the development of abstract thinking: to effectively transform the world according to their survival needs, individuals co-construct structured concepts of it; by doing so, humans fundamentally transform not merely the world they are being in, but their being in the world.

Coordination in interpersonal systems

Coordinated group behaviour can result in conflict or social cohesion. Thus having a better understanding of coordination in social groups could help us tackle some of our most challenging social problems. Historically, the most common way to study group behaviour is to break it down into sub-processes, such as cognition and emotion, then ideally manipulate them in a social context in order to predict some behaviour such as liking versus distrusting a target person. This approach has gotten us partway to understanding many important collective behaviours, but I argue that making major changes in the world will require a more integrated approach. In this review, I introduce dynamic systems theory, with a focus on interpersonal systems, where all the processes we typically study in individuals, such as cognition and emotion, become intertwined between social partners over time. I focus on the concept of coordination, defined as a temporal correlation between interacting components of a system (or systems) arising due to coupling between them. Finally, I show how this perspective could be used to guide investigations of social problems such as polarisation.

Understanding human encounters goes beyond explaining musculoskeletal coordination: a review

Complex systems theory has become one of the main frameworks to understand, model and explain interactional phenomena such as interpersonal coordination. In her paper, Butler (this issue) applies this approach to theorise about coordination at large, including human interactions. We argue that the all-encompassing language of complex systems theory leads to overemphasising the physical aspects that human interactions share with other coordinated systems in nature. This emphasis ultimately disregards the meaningful dimension implied in any human movement, understanding it as mechanical motion, rather than expressive actions.

Child language and autism diagnosis impact hierarchical temporal structure of parent-child vocal interactions in early childhood

Timing is critical to successful social interactions. The temporal structure of dyadic vocal interactions emerges from the rhythm, timing, and frequency of each individuals' vocalizations and reflects how the dyad dynamically organizes and adapts during an interaction. This study investigated the temporal structure of vocal interactions longitudinally in parent-child dyads of typically developing (TD) infants (n = 49; 9-18 months; 48% male) and toddlers with ASD (n = 23; 27.2 ± 5.0 months; 91.3% male) to identify how developing language and social skills impact the temporal dynamics of the interaction. Acoustic hierarchical temporal structure (HTS), a measure of the nested clustering of acoustic events across multiple timescales, was measured in free play interactions using Allan Factor. HTS reflects a signal's temporal complexity and variability, with greater HTS indicating reduced flexibility of the dyadic system. Child expressive language significantly predicted HTS (ß = -0.2) longitudinally across TD infants, with greater dyadic HTS associated with lower child language skills. ASD dyads exhibited greater HTS (i.e., more rigid temporal structure) than nonverbal matched (d = 0.41) and expressive language matched TD dyads (d = 0.28). Increased HTS in ASD dyads occurred at timescales >1 s, suggesting greater structuring of pragmatic aspects of interaction. Results provide a new window into how language development and social reciprocity serve as constraints to shape parent-child interaction dynamics and showcase a novel automated approach to characterizing vocal interactions across multiple timescales during early childhood.

The puzzle of ideography

An ideography is a general-purpose code made of pictures that do not encode language, which can be used autonomously - not just as a mnemonic prop - to encode information on a broad range of topics. Why are viable ideographies so hard to find? I contend that self-sufficient graphic codes need to be narrowly specialized. Writing systems are only an apparent exception: At their core, they are notations of a spoken language. Even if they also encode nonlinguistic information, they are useless to someone who lacks linguistic competence in the encoded language or a related one. The versatility of writing is thus vicarious: Writing borrows it from spoken language. Why is it so difficult to build a fully generalist graphic code? The most widespread answer points to a learnability problem. We possess specialized cognitive resources for learning spoken language, but lack them for graphic codes. I argue in favor of a different account: What is difficult about graphic codes is not so much learning or teaching them as getting every user to learn and teach the same code. This standardization problem does not affect spoken or signed languages as much. Those are based on cheap and transient signals, allowing for easy online repairing of miscommunication, and require face-to-face interactions where the advantages of common ground are maximized. Graphic codes lack these advantages, which makes them smaller in size and more specialized.

The dynamics of musical participation

In this paper we argue that our comprehension of musical participation-the complex network of interactive dynamics involved in collaborative musical experience-can benefit from an analysis inspired by the existing frameworks of dynamical systems theory and coordination dynamics. These approaches can offer novel theoretical tools to help music researchers describe a number of central aspects of joint musical experience in greater detail, such as prediction, adaptivity, social cohesion, reciprocity, and reward. While most musicians involved in collective forms of musicking already have some familiarity with these terms and their associated experiences, we currently lack an analytical vocabulary to approach them in a more targeted way. To fill this gap, we adopt insights from these frameworks to suggest that musical participation may be advantageously characterized as an open, non-equilibrium, dynamical system. In particular, we suggest that research informed by dynamical systems theory might stimulate new interdisciplinary scholarship at the crossroads of musicology, psychology, philosophy, and cognitive (neuro)science, pointing toward new understandings of the core features of musical participation.

Classifying Conversational Entrainment of Speech Behavior: An Expanded Framework and Review

Conversational entrainment, also known as alignment, accommodation, convergence, and coordination, is broadly defined as similarity of communicative behavior between interlocutors. Within current literature, specific terminology, definitions, and measurement approaches are wide-ranging and highly variable. As new ways of measuring and quantifying entrainment are developed and research in this area continues to expand, consistent terminology and a means of organizing entrainment research is critical, affording cohesion and assimilation of knowledge. While systems for categorizing entrainment do exist, these efforts are not entirely comprehensive in that specific measurement approaches often used within entrainment literature cannot be categorized under existing frameworks. The purpose of this review article is twofold: First, we propose an expanded version of an earlier framework which allows for the categorization of all measures of entrainment of speech behaviors and includes refinements, additions, and explanations aimed at improving its clarity and accessibility. Second, we present an extensive literature review, demonstrating how current literature fits into the given framework. We conclude with a discussion of how the proposed entrainment framework presented herein can be used to unify efforts in entrainment research.

Reaction time coupling in a joint stimulus-response task: A matter of functional actions or likable agents?

Shaping one owns actions by observing others’ actions is driven by the deep-rooted mechanism of perception-action coupling. It typically occurs automatically, expressed as for example the unintentional synchronization of reaction times in interactive games. Theories on perception-action coupling highlight its benefits such as the joint coordination of actions to cooperatively perform tasks properly, the learning of novel actions from others, and the bonding with likable others. However, such functional aspects and how they shape perception-action coupling have never been compared quantitatively. Here we tested a total of hundred-fifteen participants that played a stimulus-response task while, in parallel, they observed videos of agents that played the exact same task several milliseconds in advance. We compared to what degree the reaction times of actions of agents, who varied their behavior in terms of functionality and likability in preceding prisoner dilemma games and quizzes, shape the reaction times of human test participants. To manipulate functionality and likability, we varied the predictability of cooperative behavior and correctness of actions of agents, respectively, resulting in likable (cooperative), dislikable (uncooperative), functional (correct actions), and dysfunctional (incorrect actions) agents. The results of three experiments showed that the participants’ reaction times correlated most with the reaction times of agents that expressed functional behavior. However, the likability of agents had no effects on reaction time correlations. These findings suggest that, at least in the current computer task, participants are more likely to adopt the timing of actions from people that perform correct actions than from people that they like.

Interpersonal Physiological Synchrony Predicts Group Cohesion

A key emergent property of group social dynamic is synchrony–the coordination of actions, emotions, or physiological processes between group members. Despite this fact and the inherent nested structure of groups, little research has assessed physiological synchronization between group members from a multi-level perspective, thus limiting a full understanding of the dynamics between members. To address this gap of knowledge we re-analyzed a large dataset (N = 261) comprising physiological and psychological data that were collected in two laboratory studies that involved two different social group tasks. In both studies, following the group task, members reported their experience of group cohesion via questionnaires. We utilized a non-linear analysis method-multidimensional recurrence quantification analysis that allowed us to represent physiological synchronization in cardiological interbeat intervals between group members at the individual-level and at the group-level. We found that across studies and their conditions, the change in physiological synchrony from baseline to group interaction predicted a psychological sense of group cohesion. This result was evident both at the individual and the group levels and was not modified by the context of the interaction. The individual- and group-level effects were highly correlated. These results indicate that the relationship between synchrony and cohesion is a multilayered construct. We re-affirm the role of physiological synchrony for cohesion in groups. Future studies are needed to crystallize our understanding of the differences and similarities between synchrony at the individual-level and synchrony at the group level to illuminate under which conditions one of these levels has primacy, or how they interact.

Synchrony During Online Encounters Affects Social Affiliation and Theory of Mind but Not Empathy

Moving together in time affects human social affiliation and cognition. However, it is unclear whether these effects hold for on-line video meetings and whether they extend to empathy (understanding or sharing others' emotions) and theory of mind (ToM; attribution of mental states to others). 126 young adult participants met through online video in unacquainted pairs. Participants either performed 3 min of synchronous arm movements paced by sounds (n = 40), asynchronous movements (n = 46) or a small talk condition (n = 40). In a subsequent empathy task, participants engaged in a conversation. A video recording of this conversation was played back, and each participant rated, at predetermined time points, how they felt and how they thought their partner felt. From this we calculated empathic accuracy (accuracy of the estimation of the other's emotions) and emotional congruence (emotion sharing). ToM was measured by showing videos of geometrical shapes interacting and asking the participants to describe what happened, measuring the amount of intentionality. We found that participants in the synchrony condition rated feeling greater closeness and similarity to their partners relative to the asynchronous condition. Further, participants in the synchrony group tended to ascribe more intentionality to the abstract shapes than participants in asynchrony condition, suggesting greater ToM. Synchrony and asynchrony groups did not reliably differ in empathic accuracy nor emotional congruence. These results suggest that moving in synchrony has effects on social affiliation measures even in online encounters. These effects extend to ToM tendencies but not empathic accuracy or emotion sharing. These results highlight the potential of synchronous movement in online encounters to affect a subset of social cognition and affiliation measures.

A systematic review and Bayesian meta-analysis of the development of turn taking in adult-child vocal interactions

Fluent conversation requires temporal organization between conversational exchanges. By performing a systematic review and Bayesian multi-level meta-analysis, we map the trajectory of infants' turn-taking abilities over the course of early development (0 to 70 months). We synthesize the evidence from 26 studies (78 estimates from 429 unique infants, of which at least 152 are female) reporting response latencies in infant-adult dyadic interactions. The data were collected between 1975 and 2019, exclusively in North America and Europe. Infants took on average circa 1 s to respond, and the evidence of changes in response over time was inconclusive. Infants' response latencies are related to those of their adult conversational partners: an increase of 1 s in adult response latency (e.g., 400 to 1400 ms) would be related to an increase of over 1 s in infant response latency (from 600 to 1857 ms). These results highlight the dynamic reciprocity involved in the temporal organization of turn-taking. Based on these results, we provide recommendations for future avenues of enquiry: studies should analyze how turn-by-turn exchanges develop on a longitudinal timescale, with rich assessment of infants' linguistic and social development.

Rhythm Perception, Speaking Rate Entrainment, and Conversational Quality: A Mediated Model

PURPOSE

Acoustic-prosodic entrainment, defined as the tendency for individuals to modify their speech behaviors to more closely align with the behaviors of their conversation partner, plays an important role in successful interaction. From a mechanistic perspective, acoustic-prosodic entrainment is, by its very nature, a rhythmic activity. Accordingly, it is highly plausible that an individual's rhythm perception abilities play a role in their ability to successfully entrain. Here, we examine the impact of rhythm perception in speaking rate entrainment and subsequent conversational quality.

METHOD

A round-robin paradigm was used to collect 90 dialogues from neurotypical adults. Additional assessments determined participants' rhythm perception abilities, social competence, and partner familiarity (i.e., whether the conversation partners knew each other prior to the interaction. Mediation analysis was used to examine the relationships between rhythm perception scores, speaking rate entrainment (using a measure of static local synchrony), and a measure of conversational success (i.e., conversational quality) based on third-party listener observations. Findings were compared to the same analysis with three additional predictive factors: participant gender, partner familiarity, and social competence.

RESULTS

Results revealed a relationship between rhythm perception and speaking rate entrainment. In unfamiliar conversation partners, there was a relationship between speaking rate entrainment and conversational quality. The relationships between entrainment and each of the three additional factors (i.e., gender, partner familiarity, and social competence) were nonsignificant.

CONCLUSIONS

In unfamiliar conversation partners, better rhythm perception abilities were indicative of increased conversational quality mediated by higher levels of speaking rate entrainment. These results support theoretical postulations specifying rhythm perception abilities as a component of acoustic-prosodic entrainment, which, in turn, facilitates conversational success. Knowledge of this relationship contributes to the development of a causal framework for considering a mechanism by which rhythm perception deficits in clinical populations may impact conversational success.