Dog-human vocal interactions match dogs' sensory-motor tuning.

Within species, vocal and auditory systems presumably coevolved to converge on a critical temporal acoustic structure that can be best produced and perceived. While dogs cannot produce articulated sounds, they respond to speech, raising the question as to whether this heterospecific receptive ability could be shaped by exposure to speech or remains bounded by their own sensorimotor capacity. Using acoustic analyses of dog vocalisations, we show that their main production rhythm is slower than the dominant (syllabic) speech rate, and that human-dog-directed speech falls halfway in between. Comparative exploration of neural (electroencephalography) and behavioural responses to speech reveals that comprehension in dogs relies on a slower speech rhythm tracking (delta) than humans' (theta), even though dogs are equally sensitive to speech content and prosody. Thus, the dog audio-motor tuning differs from humans', and we hypothesise that humans may adjust their speech rate to this shared temporal channel as means to improve communication efficacy.

Behavioural synchronization and social referencing of dogs and humans: walking in dyad vs in group.

Recent studies have demonstrated that dogs synchronize their locomotor behaviour with that of their owners. The present study aims to improve our understanding of the sensorimotor processes underlying interspecific behavioural synchronization by testing the influence of the number of humans on dogs' behavioural synchronization. We used Global Positioning System (GPS) devices in an outdoor environment to measure dogs' behavioural synchronization to humans during a locomotor activity involving three speeds (static, slow walking and fast walking). For half of the dogs, only their owner was walking, while for the other half, the owner walked with two familiar people. We also tested the effect of dog breeds by involving 30 shepherd dogs and 30 molossoids. Our results showed that dogs exhibited the same level of behavioural synchronization with their owner if alone or if surrounded by two familiar people. Though the presence of a group of humans did not strengthen the dogs' locomotor synchronization, it did produce another effect: dogs gazed at their owners more frequently in the presence of a group compared to their owner alone. This result suggests the same level of locomotor social entrainment but a difference in social referencing depending on the number of humans.

Pet dogs exhibit social preference for people who synchronize with them: what does it tell us about the evolution of behavioral synchronization?

Humans show greater affiliation with people who are behaviorally synchronized with them but little is known about the impact of synchronization at an interspecific level. We, therefore, explored whether the synchronization of humans with dogs affects dogs' human preferences. Pet dogs were exposed to two unfamiliar persons: one synchronized her walking behavior with them and one walked randomly. In a preference test, molossoids exhibited a clear social preference for the synchronized person, unlike shepherds. We conclude that pet dogs show a greater affiliation with humans who mimic their walking behavior, although genetic selection modulates this propensity. Behavioral synchronization, therefore, acts as a social glue in dogs too. It is the first time that such a human-like ability has been highlighted in domesticated canids at an interspecific level. Implications for the evolution of behavioral synchronization are discussed.

Manipulating social cues in baboon gesture learning: what does it tell us about the evolution of communication?

Reading the attentional state of an audience is crucial for effective intentional communication. This study investigates how individual learning experience affects subsequent ability to tailor gestural communication to audience visual attention. Olive baboons were atypically trained to request food with gestures by a human standing in profile, while not having access to her face. They were tested immediately after training, and then 1 year later in conditions that varied the human's cues to attention. In immediate testing, these baboons (profile group baboons) gestured towards untrained cues regardless of their relevance for visual communication. They were also less discriminant towards trained versus untrained cues than baboons trained by a human facing them (face group baboons, tested in Bourjade et al. Anim Behav 87:121-128; Bourjade et al., Anim Behav 87:121-128, 2014). In delayed testing, the number of gestures towards meaningful untrained cues increased and profile group baboons discriminated the orientation of the human body, a conspicuous proxy of visual attention. Our results provide support for the primary interplay between implicit learning and systematically reinforced associations made through explicit training in the scaffolding of intentional gesturing tuned to audience attention.

Pet dogs synchronize their walking pace with that of their owners in open outdoor areas.

Affiliation between interacting partners is associated with a high level of behavioural synchronization in many species. Pet dogs are known to share strong affiliative bonds with their owners and to synchronize their behaviour with them when moving freely indoors. Surprisingly, outdoor dog-human interspecific synchronization has seldom been investigated. We therefore explored whether, when allowed to move freely in a familiar outdoor space, dogs synchronize their behaviour with their owners' movements. We found that dogs visibly synchronized both their location (staying in close proximity) and their activity (moving when their owner moved, and at the same pace, and standing still when their owner stood still) with those of their owners. By demonstrating that owners act as attractors for their dogs in an outdoor space, the present study contributes new data to the understanding of interspecific behavioural synchronization.

Behavioral synchronization and affiliation: Dogs exhibit human-like skills.

Behavioral synchronization is evolutionary adaptive, fostering social cohesion. In humans, affiliation between partners is associated with a high level of behavioral synchronization; people show increased affiliation towards people who synchronize with them. Surprisingly, until recently, little was known about these phenomena at an interspecific level, which is, however, essential to better understand the respective roles of evolution and ontogeny. After presenting why dog-human dyads are a relevant biological model to study this field of social cognition, we review the recent findings about dog-human behavioral synchronization. We summarize recently published findings on behavioral synchronization and affiliation between dogs and humans. We also review results showing that genetic selection modulates behavioral synchronization propensity in dogs, emphasizing the role of genetic selection on dog's social behaviors towards humans. Finally, we discuss the possible evolutionary influences and proximate mechanisms of this phenomenon. We conclude that, as in humans, behavioral synchronization acts as a social glue between dogs and humans. After dogs' ability to use human-directional cues or to produce referential cues towards humans, we evidenced a new human-like social process in the dog, at the interspecfic level with humans.

Training experience in gestures affects the display of social gaze in baboons' communication with a human.

Gaze behaviour, notably the alternation of gaze between distal objects and social partners that accompanies primates' gestural communication is considered a standard indicator of intentionality. However, the developmental precursors of gaze behaviour in primates' communication are not well understood. Here, we capitalized on the training in gestures dispensed to olive baboons (Papio anubis) as a way of manipulating individual communicative experience with humans. We aimed to delineate the effects of such a training experience on gaze behaviour displayed by the monkeys in relation with gestural requests. Using a food-requesting paradigm, we compared subjects trained in requesting gestures (i.e. trained subjects) to naïve subjects (i.e. control subjects) for their occurrences of (1) gaze behaviour, (2) requesting gestures and (3) temporal combination of gaze alternation with gestures. We found that training did not affect the frequencies of looking at the human's face, looking at food or alternating gaze. Hence, social gaze behaviour occurs independently from the amount of communicative experience with humans. However, trained baboons-gesturing more than control subjects-exhibited most gaze alternation combined with gestures, whereas control baboons did not. By reinforcing the display of gaze alternation along with gestures, we suggest that training may have served to enhance the communicative function of hand gestures. Finally, this study brings the first quantitative report of monkeys producing requesting gestures without explicit training by humans (controls). These results may open a window on the developmental mechanisms (i.e. incidental learning vs. training) underpinning gestural intentional communication in primates.

Marked referential communicative behaviours, but no differentiation of the "knowledge state" of humans in untrained pet dogs versus 1-year-old infants.

The study examines whether untrained dogs and infants take their caregiver's visual experience into account when communicating with them. Fifteen adult dogs and 15 one-year-old infants were brought into play with their caregivers with one of their own toys. The caregiver gave the toy to the experimenter, who, in different conditions, placed it either above or under one of two containers, with both the infant or dog and the caregiver witnessing the positioning; in a third condition, the caregiver left the room before the toy was placed under one of the two containers and later returned. Afterwards, for each condition, the caregiver asked the participant to indicate the location of the toy. Neither dogs nor infants-untrained to the use of the partner's knowledge state-showed much difference of behaviour between the three conditions. However, dogs showed more persistence for most behaviours (gaze at the owner, gaze at the toy and gaze alternation) and conditions, suggesting that the situation made more demands on dogs' communicative behaviours than on those of infants. When all deictic behaviours of infants (arm points towards the toy and gaze at the toy) were taken into account, dogs and infants did not differ. Phylogeny, early experience and ontogeny may all play a role in the ways that both species communicate with adult humans.

Description of dogs and owners in outdoor built-up areas and their more-than-human issues.

Tensions are generated by the inevitable presence of dogs accompanying humans in cities. Built-up outdoor areas, spaces that are "in between" the home and dog parks, are widely frequented by dogs and their owners. The present case study, performed in Lyon (France), is the first to provide a description of these dyads in areas that vary according to terrain, district, dog legislation and use in three areas: a busy street where dogs are allowed and a park and a square where dogs are forbidden. Dog-owner profiles were identified. They adjusted their presence differently across areas and according to anthropogenic and ecological pressures, such as day of the week, time of day, weather, frequentation, and legislation. They mutually adapted their behaviors. Interactions between dogs or owners and other social agents were few; dogs primarily sniffed and urinated. There was little barking, no aggression, minor impact on the environment, and, despite instances of dogs appropriating forbidden areas and dogs off their leashes, the dogs seemed to go virtually unnoticed. The study shows how the need for more-than-human areas is evident in outdoor built-up areas (for instance, the results on types of interaction and activity across areas, absence of a leash, and appropriation of forbidden areas) as well as how the cultural and natural aspects of dogs play out. The results suggest that dog regulations should be adjusted in outdoor built-up areas and that dog parks should be developed.

Behavioural Synchronisation between Dogs and Humans: Unveiling Interspecific Motor Resonance?

Dogs' behavioural synchronisation with humans is of growing scientific interest. However, studies lack a comprehensive exploration of the neurocognitive foundations of this social cognitive ability. Drawing parallels from the mechanisms underlying behavioural synchronisation in humans, specifically motor resonance and the recruitment of mirror neurons, we hypothesise that dogs' behavioural synchronisation with humans is underpinned by a similar mechanism, namely interspecific motor resonance. Based on a literature review, we argue that dogs possess the prerequisites for motor resonance, and we suggest that interspecific behavioural synchronisation relies on the activation of both human and canine mirror neurons. Furthermore, interspecific behavioural studies highlight certain characteristics of motor resonance, including motor contagion and its social modulators. While these findings strongly suggest the potential existence of interspecific motor resonance, direct proof remains to be established. Our analysis thus paves the way for future research to confirm the existence of interspecific motor resonance as the neurocognitive foundation for interspecific behavioural synchronisation. Unravelling the neurocognitive mechanisms underlying this behavioural adjustment holds profound implications for understanding the evolutionary dynamics of dogs alongside humans and improving the day-to-day management of dog-human interactions.

Does visual experience influence arm proprioception and its lateralization? Evidence from passive matching performance in congenitally-blind and sighted adults.

In humans, body segments' position and movement can be estimated from multiple senses such as vision and proprioception. It has been suggested that vision and proprioception can influence each other and that upper-limb proprioception is asymmetrical, with proprioception of the non-dominant arm being more accurate and/or precise than proprioception of the dominant arm. However, the mechanisms underlying the lateralization of proprioceptive perception are not yet understood. Here we tested the hypothesis that early visual experience influences the lateralization of arm proprioceptive perception by comparing 8 congenitally-blind and 8 matched, sighted right-handed adults. Their proprioceptive perception was assessed at the elbow and wrist joints of both arms using an ipsilateral passive matching task. Results support and extend the view that proprioceptive precision is better at the non-dominant arm for blindfolded sighted individuals. While this finding was rather systematic across sighted individuals, proprioceptive precision of congenitally-blind individuals was not lateralized as systematically, suggesting that lack of visual experience during ontogenesis influences the lateralization of arm proprioception.

One- and Two-Month-Old Dog Puppies Exhibit Behavioural Synchronization with Humans Independently of Familiarity.

Behavioural synchronization is a widespread skill in social species as it helps increase group cohesion among individuals. Such a phenomenon is involved in social interactions between conspecifics as well as between individuals from different species. Most importantly, familiarity and affiliation between interacting partners influence the degree of behavioural synchronization they would exhibit with each other. For example, in human-dog dyads, the more a dog is affiliated with its human partner, the more it behaves in a synchronous way with them. However, little is known about the ontogeny of such a behaviour, especially from an interspecific perspective. The aim of the present study was thus to investigate the existence and modalities of activity synchrony, a type of behavioural synchronization, between humans and puppies. To do so, we observed 29 dog puppies interacting with two different humans (familiar and unfamiliar experimenters). Puppy movements and general activity in relation to the human ones were observed. Results evidenced that puppies did exhibit locomotor synchrony with humans, but familiarity did not affect its degree. It is the first time that activity synchrony with human walk is evidenced in puppies, highly suggesting that dogs' ability to behave in synchronization with humans seems to be genetically selected through the process of domestication, while the effect of familiarity on it might develop later during the individual ontogeny.

Functionally referential and intentional communication in the domestic dog: effects of spatial and social contexts.

In apes, four criteria are set to explore referential and intentional communication: (1) successive visual orienting between a partner and distant targets, (2) the presence of apparent attention-getting behaviours, (3) the requirement of an audience to exhibit the behaviours, and (4) the influence of the direction of attention of an observer on the behaviours. The present study aimed at identifying these criteria in behaviours used by dogs in communicative episodes with their owner when their toy is out of reach, i.e. gaze at a hidden target or at the owner, gaze alternation between a hidden target and the owner, vocalisations and contacts. In this study, an additional variable was analysed: the position of the dog in relation to the location of the target. Dogs witnessed the hiding of a favourite toy, in a place where they could not get access to. We analysed how dogs engaged in communicative deictic behaviours in the presence of their owner; four heights of the target were tested. To control for the motivational effects of the toy on the dogs' behaviour and for the referential nature of the behaviours, observations were staged where only the toy or only the owner was present, for one of the four heights. The results show that gazing at the container and gaze alternation were used as functionally referential and intentional communicative behaviours. Behavioural patterns of dog position, the new variable, fulfilled the operational criteria for functionally referential behaviour and a subset of operational criteria for intentional communication: the dogs used their own position as a local enhancement signal. Finally, our results suggest that the dogs gazed at their owner at optimal locations in the experimental area, with respect to the target height and their owner's (or their own) line of gaze.

How do guide dogs and pet dogs (Canis familiaris) ask their owners for their toy and for playing?

When apes are not fully understood by humans, they persist with attempts to communicate, elaborating their behaviours to better convey their meaning. Such abilities have never been investigated in dogs. The present study aimed to clarify any effect of the visual attentional state of the owner on dogs' (Canis familiaris) social-communicative signals for interacting with humans, and to determine whether dogs persist and elaborate their behaviour in the face of failure to communicate a request. Gaze at a hidden target or at the owner, gaze alternation between a hidden target and the owner, vocalisations and contacts in 12 guide and 12 pet dogs were analysed (i) when the dogs were asked by their owners (blind or sighted) to fetch their inaccessible toy and (ii) when the dogs were subsequently given an unfamiliar object (apparent unsuccessful communication) or their toy (apparent successful communication). No group differences were found, indicating no effect of the visual status of the owner on the dogs' socio-communicative modes (i.e. no sensitivity to human visual attention). Results, however, suggest that the dogs exhibited persistence (but not elaboration) in their "showing" behaviours in each condition, except that in which the toy was returned. Thus, their communication was about a specific item in space (the toy). The results suggest that dogs possess partially intentional non-verbal deictic abilities: (i) to get their inaccessible toy, the dogs gazed at their owners as if to trigger their attention; gaze alternation between the owner and the target direction, and two behaviours directed at the target were performed, apparently to indicate the location of the hidden toy; (ii) after the delivery of the toy, the dogs behaved as if they returned to the play routine, gazing at their owner whilst holding their toy. In conclusion, this study shows that dogs possess partially intentional non-verbal deictic abilities: they exhibit successive visual orienting between a partner and objects, apparent attention-getting behaviours, no sensitivity to the visual status of humans for communication, and persistence in (but no elaboration of) communicative behaviours when apparent attempts to "manipulate" the human partner fail.

Coexistence of Diversified Dog Socialities and Territorialities in the City of Concepción, Chile.

There has been scant research on the presence of stray dogs in cities. Studying their very considerable presence in Concepción (Chile) provided a unique opportunity to learn more about the different patterns of sociality and territoriality exhibited by the dog species. Via a set of case studies, we examined the behavior of urban dogs, adopting an ethnographic methodology. This yielded findings of the dogs' cognitive, social and spatial adjustment abilities, i.e., their territorialities. Our hypothesis was validated: We found numerous types of sociability, we confirmed the presence of two previously established categories: family dogs (pets, guard dogs and beggars' dogs) and stray dogs (dogs almost entirely unused to humans, aggressive dogs at the far end of the campus and feral dogs in the woods). We also identified three new ones: familiar stray dogs in packs (dogs both spatially and socially close to humans), pet-stray dogs (i.e., village dogs interacting closely with people) and free-roaming pet dogs. We conclude that an ongoing two-way bond between humans and animals allowed these dogs to became part of a city's urban identity and explains the stray dogs' plasticity in terms of adapting to the diversified urban habitat. We postulate that it was the human culture and range of urban areas in Concepción that gave rise to this unique diversity of sociospatial positioning and level of adjustment (e.g., dogs crossing crosswalks).

The response of guide dogs and pet dogs (Canis familiaris) to cues of human referential communication (pointing and gaze).

The study raises the question of whether guide dogs and pet dogs are expected to differ in response to cues of referential communication given by their owners; especially since guide dogs grow up among sighted humans, and while living with their blind owners, they still have interactions with several sighted people. Guide dogs and pet dogs were required to respond to point, point and gaze, gaze and control cues of referential communication given by their owners. Results indicate that the two groups of dogs do not differ from each other, revealing that the visual status of the owner is not a factor in the use of cues of referential communication. Both groups of dogs have higher frequencies of performance and faster latencies for the point and the point and gaze cues as compared to gaze cue only. However, responses to control cues are below chance performance for the guide dogs, whereas the pet dogs perform at chance. The below chance performance of the guide dogs may be explained by a tendency among them to go and stand by the owner. The study indicates that both groups of dogs respond similarly in normal daily dyadic interaction with their owners and the lower comprehension of the human gaze may be a less salient cue among dogs in comparison to the pointing gesture.

Guide dogs' navigation after a single journey: A descriptive study of path reproduction, homing, shortcut and detour.

Guide dogs are working dogs that follow the verbal instructions of owners with severe visual impairments, leading them through the environment and toward goals such as a subway entrance ("Find the subway" instruction). During this process, guide dogs incidentally familiarize themselves with their environment. As such, they provide a unique animal model for studying wayfinding abilities in the canine species. In the present descriptive study, 23 skilled guide dogs travelled along a path once and were subsequently tested in a navigation task, with a blindfolded guide dog instructor as the handler. Dogs had difficulty reproducing the path (only 30.43% of the dogs succeeded) and returning (homing) along the previously travelled path (43.47% of the dogs succeeded). However, 80% of them successfully took a shortcut, and 86.95% a detour. This is the first description of the wayfinding abilities of dogs after a single discrete exploration of the path (incidental learning) in systematic experimental conditions. Errors, initiatives and success rates showed that dogs were able to keep track of the goal if the path was short, but errors increased with longer paths, suggesting segmented integration of path characteristics process, as demonstrated in humans. Additionally, errors on homing and detouring, both vital wayfinding tasks, were correlated, suggesting an effect of experience. Initiatives taken by the dogs further suggest flexibility of the spatial representation elaborated. Interestingly, we also found that homing was the only task to benefit from severe visual disability and regular exposure to new journeys, suggesting that these two factors influence the most important wayfinding task. This study therefore highlights qualitative and quantitative wayfinding abilities in the dog species, as well as the factors that account for them, after a single path exploration accompanied by natural ongoing motivation. In the wake of the discovery that dogs are sensitive to the magnetic field, our results provide the basis for developing systematic wayfinding tests for guide dogs.

When walking in an outside area, shelter dogs (Canis familiaris) synchronize activity with their caregivers but do not remain as close to them as do pet dogs.

When taken for walks, pet dogs synchronize their walking with that of their owners. The aim of this study was to ascertain whether shelter dogs do the same with their caregivers. We documented the behavior of 30 shelter dogs when they were taken outside in their regular walking area by their principal caregivers. The caregivers were instructed to behave in three ways: stay still, walk normally, and walk fast. The shelter dogs synchronized their locomotor activity with their caregiver less strongly than did pet dogs in a previous study. Shelter dogs also maintained greater distances to their caregivers than pet dogs with their owners. The present study predicts that the strength of the social bond between the caregiver and the dog explains most of the findings, which are similar to those found between adult human interacting partners. Further research could disentangle what aspects of experience contribute to the differences between pet dogs and shelter dogs in behavioral synchronization with a familiar human. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Interspecific behavioural synchronization: dogs exhibit locomotor synchrony with humans.

Behavioural synchronization is widespread among living beings, including humans. Pairs of humans synchronize their behaviour in various situations, such as walking together. Affiliation between dyadic partners is known to promote behavioral synchronization. Surprisingly, however, interspecific synchronization has recived little scientific investigation. Dogs are sensitive to human cues, and share strong affiliative bonds with their owners. We thus investigated whether, when allowed to move freely in an enclosed unfamiliar space, dogs synchronize their behaviour with that of their owners'. We found that dogs visibly synchronized their location with their owner (staying in close proximity and moving to the same area), as well as their activity and temporal changes in activity (moving when their owner moved, standing still when their owner stood still, and gazing in the same direction as their owner). The present study demonstrates that owners act as attractors for their dogs in an indoor space, as mothers do for their children.

[Studying episodic memory : dogs as a biological model ?] / La mémoire autobiographique/épisodique : le chien, un modèle d'étude ?

The ability to remember past events in all of their dimensions (what? where? when? i.e. autobiographic/episodic memory) is highly adaptive. Conversely, individuals who do not have such ability are less likely to benefit from recognizing situations similar to previous ones, e.g. to avoid being defeated several times. We will present the different types of memory and their ontogeny, focusing on those that are found in dogs. We will then describe more precisely the episodic memory, i.e. remembering events or actions from others, and their location and the time of the events and will present to which degree such a skill is found in dogs. We will show that, even if dogs are a social species whose specificities should reveal the existence of an episodic-like memory, dogs remember who and what happened but no study evidenced yet that they remember the precise time it was done. Further studies are thus needed, especially as dogs represent a relevant biological model for comparative cognition to study the ontogeny or senescence of non verbal episodic memory.