Longitudinal study of personal space in autism.

The size and regulation of personal space are reportedly atypical in autistic individuals. As personal space regulates social interaction, its developmental change is essential for understanding the nature of social difficulties that autistic individuals face. Adolescence is an important developmental period in which social relationships become complex. We conducted a three-year longitudinal study of interpersonal distances in autistic and typically developing (TD) individuals aged 12-18 years at Time 1 and 15-21 years at Time 2. Their preferred interpersonal distances were measured when an experimenter approached the participants with and without eye contact. The interpersonal distances of autistic individuals were shorter than those of TD individuals at both Time 1 and Time 2. Furthermore, the interpersonal distances of autistic individuals at Time 1 and Time 2 were highly correlated, but no such correlation was found in TD individuals. The results suggest that the interpersonal distances of autistic individuals are stable and that the shorter preferred interpersonal distances in autistic individuals compared to those of TD individuals are maintained during adolescence.

Testosterone promotes dominance behaviors in the Ultimatum Game after players' status increases.

Although testosterone is generally considered to promote dominance behaviors, in humans it fosters behaviors appropriate to achieving and maintaining social status, contingent upon the situation. Recent cross-sectional studies, such as Inoue et al. (Sci Rep 7:5335, 2017), have shown that dominance behaviors induced by testosterone are modulated by high status. Yet, it remains ambiguous whether a rise in social status within real-world social groups reshapes the relationship between testosterone and dominance behavior. To investigate this longitudinal question, we added a second wave to Inoue et al.'s study, collecting further data after an interval of 2 years. Members of a university rugby team that adheres to a rigid hierarchical order rooted in seniority played the Ultimatum Game with teammates and provided saliva for assays of testosterone and cortisol. Our analysis reveals that individuals with higher baseline salivary testosterone levels exhibited more dominance as their position in the hierarchy increased according to their seniority.

Attention to live eye contact in adolescents with autism spectrum disorder.

A number of studies have reported diminished attention to the eyes in individuals with autism spectrum disorder (ASD). These studies predominantly used static images of faces as stimuli. Recent studies, however, have shown enhanced response to eye contact in typically developing (TD) individuals when they observe a person in a live interaction. We investigated physiological orienting to perceived eye contact in adolescents with ASD and TD adolescents when they observed a person in live interaction or viewed a photograph of the same person's face. We measured heart rate (HR) deceleration as an index of attentional orienting. Adolescents with ASD, as well as TD adolescents, showed significant HR deceleration for the direct gaze compared to an averted gaze in the live condition, but not in the photographic condition. The results suggest an intact response to perceived eye contact in individuals with ASD during a live face-to-face interaction. LAY SUMMARY: Individuals with autism spectrum disorder (ASD) have a different eye gaze pattern when observing photographic faces. However, little is known about how individuals with ASD process a real person's face. We measured heart rate (HR) and found that adolescents with ASD showed the typical decline in HR when they made eye contact with a real person, which suggests that both groups of individuals directed their attention to eye contact in a live face-to-face interaction.

Face-to-face configuration in Japanese macaques functions as a platform to establish mutual engagement in social play.

A face-to-face configuration and eye-to-eye contact are considered a basis for intersubjectivity, as they create a situation in which interactants are mutually attentive. Studies in humans have shown that the face-to-face configuration establishes active engagement by interactants in subsequent interactions, but it is not clear whether a similar function exists in non-human animals. Using data from a group of Japanese macaques (Macaca fuscata), this study compared dyadic play fighting sessions preceded and not preceded by a face-to-face configuration. During play fighting, players compete to gain an advantage over their playmates by attacking them unilaterally (i.e., attacking them without being attacked or pinning them to the ground). Defining the inter-player asymmetry of active engagement in play in terms of the difference in the duration of each individual's advantage over the other, we found that asymmetry was lower in play bouts with a face-to-face beginning than in play bouts without one. Additionally, in play bouts not preceded by a face-to-face configuration, individuals who faced their partner at the onset of play unilaterally attacked their partner for a significantly longer duration than did those who did not face their partner at the onset of play. Conversely, in play bouts preceded by a face-to-face configuration, there was no difference in the duration of unilateral attacks. Overall, our results indicated that the face-to-face configuration in Japanese macaques functions as a platform to establish mutual engagement by interactors and enhances symmetry within play interaction.

Face-to-face opening phase in Japanese macaques' social play enhances and sustains participants' engagement in subsequent play interaction.

A face-to-face "opening phase" in human interaction serves as a platform for the interactants to initiate and manage their interaction collaboratively. This study investigated whether, as is the case in humans, a face-to-face opening phase in animal interaction serves to manage a subsequent interaction and establish interactants' engagement. We compared the dyadic play fighting of Japanese macaques (Macaca fuscata) initiated with and without a face-to-face opening phase. Our observations showed that play sessions with a face-to-face opening phase lasted longer than did sessions without one. Furthermore, our results indicate that facing toward playmates was a sign of interactants' engagement. In sessions with a face-to-face opening phase, both players were likely to gain an advantage over their playmates, whereas in sessions without such an opening phase, only an individual who unidirectionally faced toward another individual who looked away when play began was likely to maintain an advantage over a long period. Our findings demonstrate that a face-to-face opening phase has a socio-cognitive function to establish and sustain interactants' social engagement during subsequent interaction not only in humans but also in Japanese macaques.

Author Correction: Domestic cats (Felis catus) discriminate their names from other words.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Domestic cats (Felis catus) discriminate their names from other words.

Two of the most common nonhuman animals that interact with humans are domestic dogs (Canis familiaris) and cats (Felis catus). In contrast to dogs, the ability of domestic cats to communicate with humans has not been explored thoroughly. We used a habituation-dishabituation method to investigate whether domestic cats could discriminate human utterances, which consisted of cats' own names, general nouns, and other cohabiting cats' names. Cats from ordinary households and from a 'cat café' participated in the experiments. Among cats from ordinary households, cats habituated to the serial presentation of four different general nouns or four names of cohabiting cats showed a significant rebound in response to the subsequent presentation of their own names; these cats discriminated their own names from general nouns even when unfamiliar persons uttered them. These results indicate that cats are able to discriminate their own names from other words. There was no difference in discrimination of their own names from general nouns between cats from the cat café and household cats, but café cats did not discriminate their own names from other cohabiting cats' names. We conclude that cats can discriminate the content of human utterances based on phonemic differences.

Surveillance on susceptibility of strains isolated from pediatric infections.

During the period from January to December 2015, 104 Streptococcus pneumoniae strains, 129 Haemophilus influenzae strains and 54 Moraxella catarrhalis strains isolated from clinical specimens of pediatric infections in the national 16 institutions, studied susceptibilities of total 28 antibiotics, the capsular serotype for S. pneumoniae, the capsular b type and ß-lactamase production capability for H. influenzae, and the ß-lactamase production capability for M. catarrhalis were measured. In S. pneumoniae, the results showed that 68 strains (65.4%) were PSSP, 32 (30.8%) were PISP, and 4 (3.8%) were PRSP. The susceptibilities of TBPM and GRNX among oral antibiotics, and PAPM among injectable antibiotics demonstrated the lowest value with MIC90 ≤ 0.06 µg/mL. The most frequent distribution of S. pneumoniae serotypes was seen in 15B, followed by 19A, and 35B. Serotype strains contained in 13-valent pneumococcal conjugate vaccine (PCV13) were 19 strains (18.3%). In H. influenzae, the results showed that BLNAS accounted for 40 strains (31.0%), BLNAI for 28 strains (21.7%), BLNAR for 47 strains (36.4%), ß-lactamase producing for 14 strains (10.8%). The susceptibilities of quinolones demonstrated the lowest outcome among oral antibiotics with MIC90 ≤ 0.06 µg/mL, and CTRX and TAZ/PIPC (TAZ4 fixed) among injectable antibiotics with MIC of 0.25 µg/mL. There was no detection of capsular type b strains. In M. catarrhalis, all the isolates were ß-lactamase producing strains. The susceptibilities of TBPM, CPFX, TFLX and GRNX among oral antibiotics, and TAZ/PIPC (TAZ4 fixed), PAPM, MEPM and DRPM among injectable antibiotics demonstrated the lowest outcome with MIC of ≤0.06 µg/mL.

Oxytocin modulates responses to inequity in dogs.

Although several animals respond negatively to inequity, the underlying neurochemistry of the process remains poorly understood. In this study, we tested whether the neuropeptide oxytocin mediates responses to inequitable outcomes in domestic dogs (Canis familiaris). Subjects exchanged tokens to receive a food reward in conditions in which the distribution of reward varied. Dogs did respond negatively to inequity, refusing to participate in the test when their partner was rewarded and they were not. Their responses could not be explained merely by frustration, since the presence of a partner being rewarded had a significant effect on their behavior, compared to when the partner was present but not rewarded. Furthermore, after oxytocin intake dogs were less sensitive to the inequitable distribution of reward, performing more successful trials than when administered with placebo. Further, oxytocin treatment also increased dogs' attention towards their partners, and slowed their decision times, but did not affect their affiliation level towards their partners or the experimenter. Together, our findings suggest that oxytocin modulates responses to inequity in dogs by potentially affecting decision-making processes, but not by increasing affiliation.

Mind perception and moral judgment in autism.

Social difficulties of autistic individuals have been suggested to be caused by mind blindness, the absence of a theory of mind. Numerous studies have investigated theory of mind in autism spectrum disorder or how autistic individuals represent the mental states of others. Here, we have examined, as an alternative, mind perception, namely how individuals perceive the minds of various animate and inanimate entities. Autistic and non-autistic participants demonstrated evidence of a similar two-dimensional mind perception; agency, capacity for doing (i.e., self-control, memory, plan), and experience, capacity for feeling (i.e., fear, hunger, pain). Some targets (e.g., human infant and dog) were perceived to have low agency but high experience, while others (e.g., robot and God) were perceived to have the reverse pattern. Moreover, in both autistic and non-autistic groups, the attribution of moral blame positively correlated with agency, whereas moral consideration positively correlated with experience. These results offer new evidence of social cognition, particularly conception of mind and morality, in autism. Autism Res 2018, 11: 1239-1244. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We found that autistic and non-autistic individuals have similar thoughts regarding the minds of various living and nonliving entities. In addition, both groups gave moral consideration or blamed entities for wrongdoing according to their conception of the minds of those entities. Autistic individuals have this mind-based moral sense, which is a pivotal element with a key role in human society.

The presence of females induces elevated cortisol levels in an alpha male: Experimental evidence in chimpanzees.

OBJECTIVES: In group-living primates, it has been reported that the alpha male exhibits high concentrations of cortisol and testosterone in the context of mating competition. We investigated how the presence of females affected salivary cortisol and testosterone levels in males from a small captive group of chimpanzees (Pan troglodytes). Specifically, we assessed whether the presence of females resulted in a rapid increase in salivary cortisol and testosterone levels in the alpha male. MATERIALS AND METHODS: We compared the social behavior and salivary hormone concentrations of four males before and after the presentation of receptive females. Three times a day, we collected saliva samples, a useful matrix for investigating short-term hormonal changes, and measured cortisol and testosterone concentration by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: The frequency of inter-male aggression increased in the presence of females, indicating intense competition among males. Salivary cortisol levels increased in all males in the presence of females; however, the increase was significantly more pronounced in the alpha male. We found a complex three-way interaction among the presence of females, sampling timings, and male dominance rank in the analysis of salivary testosterone. Contrary to our prediction, a post hoc analysis revealed that salivary testosterone levels decreased after female introduction and that the alpha male did not show a higher level of salivary testosterone. CONCLUSIONS: Our study provides experimental evidence suggesting that the presence of females plays a significant role in the rank-related variation in the cortisol levels in male chimpanzees. Furthermore, our findings demonstrate the usefulness of salivary hormones for detecting short-term physiological changes in studies of socioendocrinology.

Cross-modal perception of human emotion in domestic horses (Equus caballus).

Humans have domesticated many kinds of animals in their history. Dogs and horses have particularly close relationships with humans as cooperative partners. However, fewer scientific studies have been conducted on cognition in horses compared to dogs. Studies have shown that horses cross-modally distinguish human facial expressions and recognize familiar people, which suggests that they also cross-modally distinguish human emotions. In the present study, we used the expectancy violation method to investigate whether horses cross-modally perceive human emotions. Horses were shown a picture of a human facial expression on a screen, and they then heard a human voice from the speaker before the screen. The emotional values of the visual and auditory stimuli were the same in the congruent condition and different in the incongruent condition. Horses looked at the speaker significantly longer in the incongruent condition than in the congruent condition when they heard their caretaker's voices but not when they heard the stranger voice. In addition, they responded significantly more quickly to the voice in the incongruent condition than in the congruent one. To the best of our knowledge, this is the first study to show that horses cross-modally recognized the emotional states of their caretakers and strangers.

Brief Report: Body Image in Autism: Evidence from Body Size Estimation.

Individuals with autism spectrum disorder (ASD) have difficulties with social interaction and communication. First-hand accounts written by individuals with ASD have shown the existence of other atypical characteristics such as difficulties with body awareness. However, few studies have examined whether such atypicalities are found more generally among individuals with ASD. We examined body image (i.e., self-body awareness) by asking individuals with ASD and typically developing (TD) individuals to estimate their own body size (shoulder width). Results show that TD individuals estimated their shoulder width more accurately than individuals with ASD. This study suggests that individuals with ASD often experience misperceptions in their body size.

Chick Development and Asynchroneous Hatching in the Zebra Finch (Taeniopygia guttata castanotis).

The mode of hatching in birds has important impacts on both parents and chicks, including the costs and risks of breeding for parents, and sibling competition in a clutch. Birds with multiple eggs in a single clutch often begin incubating when most eggs are laid, thereby reducing time of incubation, nursing burden, and sibling competition. In some songbirds and some other species, however, incubation starts immediately after the first egg is laid, and the chicks thus hatch asynchronously. This may result in differences in parental care and in sibling competition based on body size differences among older and younger chicks, which in turn might produce asynchronous development among siblings favoring the first hatchling, and further affect the development and fitness of the chicks after fledging. To determine whether such processes in fact occur in the zebra finch, we observed chick development in 18 clutches of zebra finches. We found that there were effects of asynchronous hatching, but these were smaller than expected and mostly not significant. Our observations suggest that the amount of care given to each chick may be equated with such factors as a camouflage effect of the down feathers, and that the low illumination within the nest also complicates the determination of the hatching order by the parents.

Testosterone promotes either dominance or submissiveness in the Ultimatum Game depending on players' social rank.

Endogenous testosterone promotes behaviours intended to enhance social dominance. However, recent research suggests that testosterone enhances strategic social behaviour rather than dominance seeking behaviour. This possibility has not been tested in a population whose members are known to vary in social status. Here, we explored the relationship between pre-existing social status and salivary testosterone level among members of a rugby team at a Japanese university, where a strong seniority norm maintains hierarchical relationships. Participants played a series of one-shot Ultimatum Games (UG) both as proposer and responder. Opponents were anonymised but of known seniority. We analysed participants' acquiescence (how much more they offered beyond the lowest offer they would accept). The results showed that, among the most senior participants, higher testosterone was associated with lower acquiescence. Conversely, higher testosterone among the lower-status participants was associated with higher acquiescence. Our results suggest that testosterone may enhance socially dominant behaviour among high-status persons, but strategic submission to seniority among lower-status persons.

Regional gray matter volume in the posterior precuneus is associated with general self-efficacy.

Motivation in doing a task is influenced not only by the expected outcome of the task but also by the belief that one has in successfully executing the task. Over time, individuals accumulate experiences that contribute toward a general belief in one's overall ability to successfully perform tasks, which is called general self-efficacy (GSE). We investigated the relationship between regional gray matter volume and individual differences in GSE. Brain anatomy was analyzed using magnetic resonance images obtained from 64 healthy right-handed participants who had completed Sherer's GSE scale. After controlling for other factors related to motivation, age, sex, and total gray matter volume of each participant, results showed that regional gray matter volume in the posterior part of the precuneus significantly and positively correlated with the GSE score. These results suggest that one's accumulated experiences of success and failure, which contribute toward GSE, also influence the anatomical characteristics of the precuneus.

Dog Breed Differences in Visual Communication with Humans.

Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the 'visual contact task' and the 'unsolvable task'. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds.

Reduced Personal Space in Individuals with Autism Spectrum Disorder.

Maintaining an appropriate distance from others is important for establishing effective communication and good interpersonal relations. Autism spectrum disorder (ASD) is a developmental disorder associated with social difficulties, and it is thus worth examining whether individuals with ASD maintain typical or atypical degrees of social distance. Any atypicality of social distancing may impact daily social interactions. We measured the preferred distances when individuals with ASD and typically developing (TD) individuals approached other people (a male experimenter) and objects (a coat rack with clothes) or when other people approached them. Individuals with ASD showed reduced interpersonal distances compared to TD individuals. The same tendency was found when participants judged their preferred distance from objects. In addition, when being approached by other people, both individuals with ASD and TD individuals maintained larger interpersonal distances when there was eye contact, compared to no eye contact. These results suggest that individuals with ASD have a relatively small personal space, and that this atypicality exists not only for persons but also for objects.

Intranasal administration of oxytocin promotes social play in domestic dogs.

In a recent paper,(1) we examined whether oxytocin in the domestic dog modulates the maintenance of close social bonds in non-reproductive contexts. We found that exogenous oxytocin promotes positive social behaviors not only toward conspecifics, but also toward human partners. Here we examined in further detail the effect that oxytocin manipulation has on social play. When sprayed with oxytocin, subjects initiated play sessions more often and played for longer periods of time than when sprayed with saline. Furthermore, after oxytocin nasal intake dogs displayed play signals more often than after saline administration, suggesting that oxytocin enhances dogs' play motivation. To our knowledge, this study provides the first evidence that oxytocin promotes social play in the domestic dog. We use these results to hypothesize on the potential therapeutic use of oxytocin for promoting social behaviors and treating social deficits in the domestic dog.