Measuring rhythms of vocal interactions: a proof of principle in harbour seal pups.

Rhythmic patterns in interactive contexts characterize human behaviours such as conversational turn-taking. These timed patterns are also present in other animals, and often described as rhythm. Understanding fine-grained temporal adjustments in interaction requires complementary quantitative methodologies. Here, we showcase how vocal interactive rhythmicity in a non-human animal can be quantified using a multi-method approach. We record vocal interactions in harbour seal pups (Phoca vitulina) under controlled conditions. We analyse these data by combining analytical approaches, namely categorical rhythm analysis, circular statistics and time series analyses. We test whether pups' vocal rhythmicity varies across behavioural contexts depending on the absence or presence of a calling partner. Four research questions illustrate which analytical approaches are complementary versus orthogonal. For our data, circular statistics and categorical rhythms suggest that a calling partner affects a pup's call timing. Granger causality suggests that pups predictively adjust their call timing when interacting with a real partner. Lastly, the ADaptation and Anticipation Model estimates statistical parameters for a potential mechanism of temporal adaptation and anticipation. Our analytical complementary approach constitutes a proof of concept; it shows feasibility in applying typically unrelated techniques to seals to quantify vocal rhythmic interactivity across behavioural contexts. This article is part of a discussion meeting issue 'Face2face: advancing the science of social interaction'.

Rhythm interaction in animal groups: selective attention in communication networks.

Animals communicating interactively with conspecifics often time their broadcasts to avoid overlapping interference, to emit leading, as opposed to following, signals or to synchronize their signalling rhythms. Each of these adjustments becomes more difficult as the number of interactants increases beyond a pair. Among acoustic species, insects and anurans generally deal with the problem of group signalling by means of 'selective attention' in which they focus on several close or conspicuous neighbours and ignore the rest. In these animals, where signalling and receiving are often dictated by sex, the process of selective attention in signallers may have a parallel counterpart in receivers, which also focus on close neighbours. In birds and mammals, local groups tend to be extended families or clans, and group signalling may entail complex timing mechanisms that allow for attention to all individuals. In general, the mechanisms that allow animals to communicate in groups appear to be fully interwoven with the basic process of rhythmic signalling. This article is part of the theme issue 'Synchrony and rhythm interaction: from the brain to behavioural ecology'.

Rhythm in dyadic interactions.

This review paper discusses rhythmic interactions and distinguishes them from non-rhythmic interactions. We report on communicative behaviours in social and sexual contexts, as found in dyads of humans, non-human primates, non-primate mammals, birds, anurans and insects. We discuss observed instances of rhythm in dyadic interactions, identify knowledge gaps and propose suggestions for future research. We find that most studies on rhythmicity in interactive signals mainly focus on one modality (acoustic or visual) and we suggest more work should be performed on multimodal signals. Although the social functions of interactive rhythms have been fairly well described, developmental research on rhythms used to regulate social interactions is still lacking. Future work should also focus on identifying the exact timing mechanisms involved. Rhythmic signalling behaviours are widespread and critical in regulating social interactions across taxa, but many questions remain unexplored. A multidisciplinary, comparative cross-species approach may help provide answers. This article is part of the theme issue 'Synchrony and rhythm interaction: from the brain to behavioural ecology'.

Interactive rhythms in the wild, in the brain, and in silico.

There are some historical divisions in methods, rationales, and purposes between studies on comparative cognition and behavioural ecology. In turn, the interaction between these two branches and studies from mathematics, computation, and neuroscience is not usual. In this short piece, we attempt to build bridges among these disciplines. We present a series of interconnected vignettes meant to illustrate what a more interdisciplinary approach looks like when successful, and its advantages. Concretely, we focus on a recent topic, namely animal rhythms in interaction, studied under different approaches. We showcase 5 research efforts, which we believe successfully link 5 particular scientific areas of rhythm research conceptualised as the following: social neuroscience, detailed rhythmic quantification, ontogeny, computational approaches, and spontaneous interactions. Our suggestions will hopefully spur a "comparative rhythms in interaction" field, which can integrate and capitalize on knowledge from zoology, comparative psychology, neuroscience, and computation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).