Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids

Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.

Identification of Genes Associated with Human-Canine Communication in Canine Evolution.

The dog (Canis familiaris) was the first domesticated animal and hundreds of breeds exist today. During domestication, dogs experienced strong selection for temperament, behaviour, and cognitive ability. However, the genetic basis of these abilities is not well-understood. We focused on ancient dog breeds to investigate breed-related differences in social cognitive abilities. In a problem-solving task, ancient breeds showed a lower tendency to look back at humans than other European breeds. In a two-way object choice task, they showed no differences in correct response rate or ability to read human communicative gestures. We examined gene polymorphisms in oxytocin, oxytocin receptor, melanocortin 2 receptor, and a Williams–Beuren syndrome-related gene (WBSCR17), as candidate genes of dog domestication. The single-nucleotide polymorphisms on melanocortin 2 receptor were related to both tasks, while other polymorphisms were associated with the unsolvable task. This indicates that glucocorticoid functions are involved in the cognitive skills acquired during dog domestication.

Horses with sustained attention follow the pointing of a human who knows where food is hidden

When interacting with humans, domesticated species may respond to communicative gestures, such as pointing. However, it is currently unknown, except for in dogs, if species comprehend the communicative nature of such cues. Here, we investigated whether horses could follow the pointing of a human informant by evaluating the credibility of the information about the food-hiding place provided by the pointing of two informants. Using an object-choice task, we manipulated the attentional state of the two informants during food-hiding events and differentiated their knowledge about the location of the hidden food. Furthermore, we investigated the horses’ visual attention levels towards human behaviour to evaluate the relationship between their motivation and their performance of the task. The result showed that horses that sustained high attention levels could evaluate the credibility of the information and followed the pointing of an informant who knew where food was hidden (Z = − 2.281, P = 0.002, n = 36). This suggests that horses are highly sensitive to the attentional state and pointing gestures of humans, and that they perceive pointing as a communicative cue. This study also indicates that the motivation for the task should be investigated to determine the socio-cognitive abilities of animals.

The Semantics of ‘Nod’ in Russian

The study was carried out by the method of semantic communicative analysis, which is used this case to the kinesics. The article proposes an invariant semantic parameter of the Russian communicative gesture ‘to nod’. On the movies dialogue material a number of possible implementations of this parameter is shown in various purports. The analysis presented in the work clarifies the place of kinesic means (posture, mimic, gesture) in the system of communicative level of the Russian language. The results of the study can serve as a basis for creating a fundamentally new dictionary description of “the nod” for the future Dictionary of Russian communicative gestures.

Shared intentionality in children with Autism Spectrum Disorder (ASD)

It is well documented that the ability and motivation to engage with others in collaborative activities with joint goals and shared intentions is the foundation of human uniqueness. However, children with Autism Spectrum Disorder (ASD) show difficulties in sharing their motives, intentions, and emotions with others about topics in the environment and manifest low levels of engagement. The purpose of the present study was to compare the level of intentionality and social engagement in 10 children with ASD and 10 typically developing (TD) children, matched for mental age, during free play interactions with their mothers. Children were video recorded while playing with their mothers in a naturalistic condition with toys provided by the researcher. For the microanalysis of the video recordings the EUDICO Linguistic Annotator was used, which permits the analysis of joint behaviors and captures subtle qualitative differences in social engagement. Results indicated that children with ASD showed deficits in joint attention, exhibited no functional play and employed less communicative gestures than their peers in the comparison group. These differences between the two groups in their mode of communication led to the emergence of two distinct patterns of engagement which depict the different level of intentionality that these groups have in sharing their experiences during mother-child interactions. These representative patterns of interaction can be used as a potential tool for early identification of children at risk of ASD well before other behaviors become fully manifested.

On the Multimodal Path to Language: The Relationship Between Rhythmic Movements and Deictic Gestures at the End of the First Year

The aim of this study is to analyze the relationship between rhythmic movements and deictic gestures at the end of the first year of life, and to focus on their unimodal or multimodal character. We hypothesize that multimodal rhythmic movement performed with an object in the hand can facilitate the transition to the first deictic gestures. Twenty-three children were observed at 9 and 12 months of age in a naturalistic play situation with their mother or father. Results showed that rhythmic movements with objects in the hand are a frequent behavior in children's repertoires. Rhythmic behaviors tend to decrease from 9 to 12 months, specifically when they are unimodal. Multimodal rhythmic behavior production at 9 months is positively related with proximal deictic gestures 3 months later. Multimodal rhythmic movements are not directly related to distal deictic gestures, but are indirectly related via proximal deictic gestures. These results highlight the relevance of multimodal behaviors in the transition to the use of early gestures, and can be considered as a transitional phenomenon between the instrumental action and early communicative gestures.

Semantically related gestures move alike: Towards a distributional semantics of gesture kinematics

Most manual communicative gestures that humans produce cannot be looked up in a dictionary, as these manual gestures inherit their meaning in large part from the communicative context and are not conventionalized. However, it is understudied to what extent the communicative signal as such — bodily postures in movement, or kinematics — can inform about gesture semantics. Can we construct, in principle, a distribution-based semantics of gesture kinematics, similar to how word vectorization methods in NLP (Natural language Processing) are now widely used to study semantic properties in text and speech? For such a project to get off the ground, we need to know the extent to which semantically similar gestures are more likely to be kinematically similar. In study 1 we assess whether semantic word2vec distances between the conveyed concepts participants were explicitly instructed to convey in silent gestures, relate to the kinematic distances of these gestures as obtained from Dynamic Time Warping (DTW). In a second director-matcher dyadic study we assess kinematic similarity between spontaneous co-speech gestures produced between interacting participants. Participants were asked before and after they interacted how they would name the objects. The semantic distances between the resulting names were related to the gesture kinematic distances of gestures that were made in the context of conveying those objects in the interaction. We find that the gestures’ semantic relatedness is reliably predictive of kinematic relatedness across these highly divergent studies, which suggests that the development of an NLP method of deriving semantic relatedness from kinematics is a promising avenue for future developments in automated multimodal recognition. Deeper implications for statistical learning processes in multimodal language are discussed.

GESTURE IN THE UDMURTS SONG CULTURE: FUNCTIONS AND SEMANTICS

The problems of non-verbal behavior remain in the shadow of the modern ethnomusicology so far. Meanwhile, spatial behavior of singers, the poses and gestures used by them during the singing are language of culture, not less informative, than musical and verbal language, but at the same time more emotional, expressive and available. Gesture as body language is usually associated with the movement of the arm, palm, head, shoulders, legs. In the present study, we operate with the broader meaning of the word “gesture” as a behavior (from Lat. Gestura). The spatial behavior of performers during the ceremony, the generally accepted postures and gestures as non-verbal language of culture are discussed in the article on the material of the Udmurt ritual song tradition. The forest landscape influences the behavioral, as well as linguistic, religious, sound picture of the world of the Finno-Ugrians. The connection between the natural geographic environment and the “mental warehouse” of the Udmurts was observed by ethnographers as early as the end of the 19th century; they noted restraint in expressing impressions, silence, extraordinary shyness and the boundless ability of Udmurts to endure. The same is noted by modern scientists. In speech communication, for example, there is an unspoken rule not to express loudly and openly your emotions; it is not customary to actively gesticulate, to speak loudly. The findings of scientists suggest that the Udmurt communicative culture belongs to the low-kinesic. The stereotypes about the modesty and timidity of the Udmurts collapse when analyzing the Udmurt rituals, in which the idea of producing magic dominates to extend the genus or future harvest. Many behavioral prohibitions are not only lifted; moreover, obscene gestures, indecent behavior are becoming a necessary condition for rituals. Singers can stomp their feet heavily, beat the rhythm with loud beats of iron objects, sing while standing on chairs. In other local traditions, the magic of production can be embodied in the body language of singers in slow rocking, round dances. The key moment of the spatial behavior of the singing participants of these rites is a side-to-side movement as a symbol of the growth of cereal crops. Ritual gestures of a handshake, bowing of the knees as communicative gestures are considered in the article. Other gestures of singers (alternating between the left and right foot subhemps, putting the palm to the mouth while singing) are designed to enhance the expressiveness of the musical rhythm or create a special sound effect. It is concluded that the song ritual communication of the Udmurts, in contrast to everyday verbal communication, is characterized by a higher level of emotionality, which is reflected in body language.