What Studying the Songs of a Distant Primate Relative Can Teach Us About Ourselves

Tarsiers are nocturnal animals. They have eyes that are heavier than their brains. They eat only insects and other living things. Tarsiers are primates, just like humans. And some species of tarsiers sing! Tarsier songs and human language are different in many ways. But if we study the similarities, it may help us better understand human language. In our study, we recorded singing tarsiers on the Indonesian island of Sulawesi. With the help of computers, we found that we could tell individual tarsiers apart based on their songs. Being able to recognize who is singing from far away may be an important function of tarsier songs. We also found that if a female speeds up her song, then the male speeds up his song, too. The ability to modify vocal output based on what others are doing is a universal in human language. Our results show that tarsiers (like humans) can change their vocalizations based on what their partner is doing. The fact that tarsiers and humans are both able to do this indicates that their common ancestor probably had this ability. Our results add support to the idea that flexibility in vocal interactions evolved long before the appearance of modern humans.

Acoustic camera system for measuring ultrasound communication in mice

Ultrasonic vocalizations in mice have recently been widely investigated as social behavior; however, using existing sound localization systems in home cages, which allow observations of more undisturbed behavior expressions, is challenging. We introduce a novel system, named USVCAM, that uses a phased microphone array and demonstrate novel vocal interactions under a resident-intruder paradigm. The extended applicability and usability of USVCAM may facilitate investigations of social behaviors and underlying physiological mechanisms.

Exploiting fashion x-commerce through the empowerment of voice in the fashion virtual reality arena

The ongoing development of eXtended Reality (XR) technologies is supporting a rapid increase of their performances along with a progressive decrease of their costs, making them more and more attractive for a large class of consumers. As a result, their widespread use is expected within the next few years. This may foster new opportunities for e-commerce strategies, giving birth to an XR-based commerce (x-commerce) ecosystem. With respect to web and mobile-based shopping experiences, x-commerce could more easily support brick-and-mortar store-like experiences. One interesting and consolidated one amounts to the interactions among customers and shop assistants inside fashion stores. In this work, we concentrate on such aspects with the design and implementation of an XR-based shopping experience, where vocal dialogues with an Amazon Alexa virtual assistant are supported, to experiment with a more natural and familiar contact with the store environment. To verify the validity of such an approach, we asked a group of fashion experts to try two different XR store experiences: with and without the voice assistant integration. The users are then asked to answer a questionnaire to rate their experiences. The results support the hypothesis that vocal interactions may contribute to increasing the acceptance and comfortable perception of XR-based fashion shopping.

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

Background: Turn taking appears to be an almost universal phenomenon in communicative behavior and requires tight coordination between interlocutors. However, there is no current consensus on how and when infants develop the ability to take turns in vocal interactions and which mechanisms are involved. Aim: The current study aims at better understanding the current state of research on the development of turn-taking behaviors in human infants. In particular, we want to map the developmental trajectory of turn-taking abilities and identify key moderators affecting them.Method: We performed a systematic review and Bayesian multilevel meta-analysis of studies reporting response latencies in infant-adult dyadic interactions.Results: We found a poorly connected field (low rate of citations between papers), from which we identified 26 studies and 78 unique estimates of infant response latency. Infants display fast response latencies at an early point in development, which gradually increase up to 40 months. Infants’ responses also appear to be strongly related to the pause duration of their adult conversational partners, and are slower in groups with atypical development.Conclusions: We identify current pitfalls and new directions of research. Specifically, we advocate for the development of shared longitudinal cross-linguistic corpora with turn-by-turn data and rich assessment of the infants' linguistic and social development. We also recommend more explicit definition and testing of computational models of the mechanisms underlying turn-taking.

Multiple dimensions of social motivation in adult female degus

Many animals become more motivated to interact after a period of isolation. This phenomenon may involve general drives, e.g. for social touch or companionship, as well as drives that are specific to particular peers, and which ultimately serve to reestablish relationships between the individuals. Female degus are known to be affiliative with multiple other individuals, including unrelated and unfamiliar conspecifics, offering an opportunity to study social motivation independent from exclusive pair-bonds or overt, same-sex competition. We attempted to disentangle factors driving peer interaction by examining reunion behavior across several social isolation and separation manipulations. High levels of interaction were observed between adult females who had been separated even without isolation, revealing a drive to re-establish relationships with specific peers. The content of separation-only reunions differed from isolation, with the latter involving more early-session interaction, higher levels of allogrooming before rear-sniffing, and a higher ratio of chitter vocalizations. To assess whether post-isolation behavior was related to stress, we examined reunions following a non-social (footshock) stressor. Like isolation, footshock increased early-session interactions, but did not increase allogrooming before rear-sniffing or chittering, as compared with controls. To test whether separation-only reunion behavior shared qualities with relationship formation, we also examined reunions of new (stranger) dyads. Strangers exhibited higher levels of interaction than cagemates, with particularly high levels of late-session rear-sniffing. Like separation-only reunions, strangers showed more non-chitter vocalizations and lower levels of allogrooming before rear-sniffing. Across experiments, an exploratory clustering method was used to identify vocalizations that differed between conditions. This yielded promising leads for future investigation, including a chaff-type syllable that may have been more common during relationship renewal. Overall, results are consistent with the hypothesis that female degu reunions are supported by both general and peer-stimulus specific drives, expressed through the structure of physical and vocal interactions over time.

Silence matters: The role of pauses during dyadic maternal and paternal vocal interactions with preterm and full-term infants

This study examined the characteristics of the vocal behaviors of parents and preterm infants, as compared to their term-born peers, at three months of age. Potential links between specific features of parental IDS and infants’ vocal activity were also sought. We analyzed the frequencies and durations of vocalizations and pauses during the dyadic interactions of 19 preterm and 19 full-term infants with their mothers and fathers. The results showed that the duration of the vocalizations was shorter for the preterm than for the full-term infants, regardless of the interactive partner. Mothers vocalized more frequently and for a longer time than fathers, regardless of the group, but only the frequency of paternal utterances was significantly and positively correlated with the frequency and duration of infant vocalizations. Frequent conversational pauses of a relatively short total duration seemed to be related to more active infants’ vocal participation, regardless of prematurity and parent gender.

Do marmosets understand others’ conversations? A thermography approach

What information animals derive from eavesdropping on interactions between conspecifics, and whether they assign value to it, is difficult to assess because overt behavioral reactions are often lacking. An inside perspective of how observers perceive and process such interactions is thus paramount. Here, we investigate what happens in the mind of marmoset monkeys when they hear playbacks of positive or negative third-party vocal interactions, by combining thermography to assess physiological reactions and behavioral preference measures. The physiological reactions show that playbacks were perceived and processed holistically as interactions rather than as the sum of the separate elements. Subsequently, the animals preferred those individuals who had been simulated to engage in positive, cooperative vocal interactions during the playbacks. By using thermography to disentangle the mechanics of marmoset sociality, we thus find that marmosets eavesdrop on and socially evaluate vocal exchanges and use this information to distinguish between cooperative and noncooperative conspecifics.

Gentle interactions with restrained and free-moving cows: Effects on the improvement of the animal-human relationship

The animal-human relationship is essential for farm animal welfare and production. Generally, gentle tactile and vocal interactions improve the animal-human relationship in cattle. However, cows that are fearful of humans avoid their close presence and touch; thus, the animal-human relationship first has to be improved to a point where the animals accept stroking before their perception of the interactions and consequently the animal-human relationship can become positive. We tested whether the animal-human relationship of cows fearful of humans is improved more effectively by gentle interactions during restraint, allowing physical contact from the beginning, or if the gentle interactions are offered while the animals are free to move, giving them more control over the situation and thus probably a higher level of agency and a more positive perception of the interactions. Thirty-six dairy cows (median avoidance distance 1.6 m) were assigned to three treatments (each n = 12): gentle vocal and tactile interactions during restraint in the feeding rack (LOCK); gentle vocal and, if possible, tactile interactions while free in the barn (FREE); routine management without additional interactions (CON). Treatments were applied for 3 min per cow on 10 d per fortnight for 6 weeks (i.e., three periods). Avoidance and approach behaviour towards humans was tested before the start of the treatment period, and then at 2-week intervals. The recorded variables were reduced to one score by Principal Component Analysis. The resulting relationship score (higher values implying a better relationship with humans) increased in all groups; the increase was stronger in FREE than in CON, with the increase in LOCK being not significantly different from the other treatment groups. Thus, we recommend that gentle interactions with cows should take place while they are unrestrained, if possible.