Kerstin Meints

Left gaze bias in humans, rhesus monkeys and domestic dogs

While viewing faces, human adults often demonstrate a natural gaze bias towards the left visual field, that is, the right side of the viewee’s face is often inspected first and for longer periods. Using a preferential looking paradigm, we demonstrate that this bias is neither uniquely human nor limited to primates, and provide evidence to help elucidate its biological function within a broader social cognitive framework. We observed that 6-month-old infants showed a wider tendency for left gaze preference towards objects and faces of different species and orientation, while in adults the bias appears only towards upright human faces. Rhesus monkeys showed a left gaze bias towards upright human and monkey faces, but not towards inverted faces. Domestic dogs, however, only demonstrated a left gaze bias towards human faces, but not towards monkey or dog faces, nor to inanimate object images. Our findings suggest that face- and species-sensitive gaze asymmetry is more widespread in the animal kingdom than previously recognised, is not constrained by attentional or scanning bias, and could be shaped by experience to develop adaptive behavioural significance.

Discrimination of human and dog faces and inversion responses in domestic dogs (Canis familiaris)

Although domestic dogs can respond to many facial cues displayed by other dogs and humans, it remains unclear whether they can differentiate individual dogs or humans based on facial cues alone and, if so, whether they would demonstrate the face inversion effect, a behavioural hallmark commonly used in primates to differentiate face processing from object processing. In this study, we first established the applicability of the visual paired comparison (VPC or preferential looking) procedure for dogs using a simple object discrimination task with 2D pictures. The animals demonstrated a clear looking preference for novel objects when simultaneously presented with prior-exposed familiar objects. We then adopted this VPC procedure to assess their face discrimination and inversion responses. Dogs showed a deviation from random behaviour, indicating discrimination capability when inspecting upright dog faces, human faces and object images; but the pattern of viewing preference was dependent upon image category. They directed longer viewing time at novel (vs. familiar) human faces and objects, but not at dog faces, instead, a longer viewing time at familiar (vs. novel) dog faces was observed. No significant looking preference was detected for inverted images regardless of image category. Our results indicate that domestic dogs can use facial cues alone to differentiate individual dogs and humans and that they exhibit a non-specific inversion response. In addition, the discrimination response by dogs of human and dog faces appears to differ with the type of face involved.

When does an ostrich become a bird? The role of typicality in early word comprehension

Which objects and animals are children willing to accept as referents for words they know? To answer this question, the authors assessed early word comprehension using the preferential looking task. Children were shown 2 stimuli side by side (a target and a distractor) and heard the target stimulus named. The target stimulus was either a typical or an atypical exemplar of the named category. It was predicted that children first connect typical examples with the target name and broaden the extension of the name as they get older to include less typical examples. Experiment 1 shows that when targets are named, 12-month-olds display an increase in target looking for typical but not atypical targets whereas 24-month-olds display an increase for both. Experiment 2 shows that 18-month-olds display a pattern similar to that of 24-month-olds. Implications for the early development of word comprehension are discussed.

Early tracking of informant accuracy and inaccuracy

Three- and four-year-old children (N = 131) were tested for their sensitivity to the accuracy and inaccuracy of informants. Children were presented with one of three conditions. In the Accurate-Inaccurate condition, one informant named objects accurately whereas the other named them inaccurately. In the Accurate-Neutral condition, one informant named objects accurately whereas the other merely drew attention to them. Finally in the Inaccurate-Neutral condition, one informant named objects inaccurately whereas the other merely drew attention to them. In subsequent test trials, 4-year-olds preferred to seek and accept information in a selective fashion across all three conditions, suggesting that they monitor informants for both accuracy and inaccuracy. By contrast, 3-year-olds were selective in the Accurate-Inaccurate and Inaccurate-Neutral conditions but not in the Accurate-Neutral condition, suggesting that they monitor informants only for inaccuracy and take accuracy for granted.

Reading faces: differential lateral gaze bias in processing canine and human facial expressions in dogs and 4-year-old children.

Sensitivity to the emotions of others provides clear biological advantages. However, in the case of heterospecific relationships, such as that existing between dogs and humans, there are additional challenges since some elements of the expression of emotions are species-specific. Given that faces provide important visual cues for communicating emotional state in both humans and dogs, and that processing of emotions is subject to brain lateralisation, we investigated lateral gaze bias in adult dogs when presented with pictures of expressive human and dog faces. Our analysis revealed clear differences in laterality of eye movements in dogs towards conspecific faces according to the emotional valence of the expressions. Differences were also found towards human faces, but to a lesser extent. For comparative purpose, a similar experiment was also run with 4-year-old children and it was observed that they showed differential processing of facial expressions compared to dogs, suggesting a species-dependent engagement of the right or left hemisphere in processing emotions.

Baby schema in human and animal faces induces cuteness perception and gaze allocation in children

The baby schema concept was originally proposed as a set of infantile traits with high appeal for humans, subsequently shown to elicit caretaking behavior and to affect cuteness perception and attentional processes. However, it is unclear whether the response to the baby schema may be extended to the human-animal bond context. Moreover, questions remain as to whether the cute response is constant and persistent or whether it changes with development. In the present study we parametrically manipulated the baby schema in images of humans, dogs, and cats. We analyzed responses of 3–6 year-old children, using both explicit (i.e., cuteness ratings) and implicit (i.e., eye gaze patterns) measures. By means of eye-tracking, we assessed children’s preferential attention to images varying only for the degree of baby schema and explored participants’ fixation patterns during a cuteness task. For comparative purposes, cuteness ratings were also obtained in a sample of adults. Overall our results show that the response to an infantile facial configuration emerges early during development. In children, the baby schema affects both cuteness perception and gaze allocation to infantile stimuli and to specific facial features, an effect not simply limited to human faces. In line with previous research, results confirm human positive appraisal toward animals and inform both educational and therapeutic interventions involving pets, helping to minimize risk factors (e.g., dog bites).

Companion Animals and Child/Adolescent Development: A Systematic Review of the Evidence

Childhood and adolescence are important developmental phases which influence health and well-being across the life span. Social relationships are fundamental to child and adolescent development; yet studies have been limited to children’s relationships with other humans. This paper provides an evidence review for the potential associations between pet ownership and emotional; behavioural; cognitive; educational and social developmental outcomes. As the field is in the early stages; a broad set of inclusion criteria was applied. A systematic search of databases and grey literature sources found twenty-two studies meeting selection criteria. The review found evidence for an association between pet ownership and a wide range of emotional health benefits from childhood pet ownership; particularly for self-esteem and loneliness. The findings regarding childhood anxiety and depression were inconclusive. Studies also showed evidence of an association between pet ownership and educational and cognitive benefits; for example, in perspective-taking abilities and intellectual development. Evidence on behavioural development was unclear due to a lack of high quality research. Studies on pet ownership and social development provided evidence for an association with increased social competence; social networks; social interaction and social play behaviour. Overall, pet ownership and the significance of children’s bonds with companion animals have been underexplored; there is a shortage of high quality and longitudinal studies in all outcomes. Prospective studies that control for a wide range of confounders are required.

Eating Apples and Houseplants: Typicality Constraints on Thematic Roles in Early Verb Learning.

Are thematic roles linked to verbs in young children as in adults or will children accept any participant in a given role with any verb? To assess early verb comprehension we used typicality ratings with adults, parental questionnaires, and Intermodal Preferential Looking with children. We predicted that children would look at named targets, would initially associate typical action-patient combinations with verbs, and accept atypical pairings as they get older. Results show that 15-month-olds do not understand verbs yet, 18-month-olds look at typical and atypical targets after naming, 24-month-olds demonstrate preferences for typical items only and 3-year-olds (and adults) accept atypical instances. Thus, children seem to start mapping verbs broadly to action-patient combinations, even implausible ones. Around 24 months they show restricted naming and accept only typical scenes congruent with their experience. By 3 years they have gained independence from this typicality-guided strategy and show adult-like behaviour in accepting even unusual pairings as fitting the verb.

Animal-assisted interventions in the classroom: a systematic review

The inclusion of animals in educational practice is becoming increasingly popular, but it is unclear how solid the evidence for this type of intervention is. The aim of this systematic review is to scrutinise the empirical research literature relating to animal-assisted interventions conducted in educational settings. The review included 25 papers; 21 from peer-reviewed journals and 4 obtained using grey literature databases. Most studies reported significant benefits of animal-assisted interventions in the school setting. Despite this, studies vary greatly in methods and design, in intervention types, measures, and sample sizes, and in the length of time exposed to an animal. Furthermore, a worrying lack of reference to risk assessment and animal welfare must be highlighted. Taken together, the results of this review show promising findings and emerging evidence suggestive of potential benefits related to animals in school settings. The review also indicates the need for a larger and more robust evidence base driven by thorough and strict protocols. The review further emphasises the need for safeguarding for all involved—welfare and safety are paramount.

Why do children get bitten in the face

The majority of dog bite accidents happen at home and involve children under the age of 7 (Kahn et al, 2003) and a familiar dog. The prevalence of bites in children is double as in the general population (Kahn et al 2004) and often children suffer from dog bites resulting in facial injuries (Bernardo et al, 2002, Kahn et al, 2003; Schalamon et al, 2006). 55% children suffer post-traumatic stress disorder following a substantial bite (Peters et al, 2004). According to research these bites are independent of the size of the dog (Kahn et al, 2003), therefore it is unclear why young children get bitten mainly in the face and neck area. As often childrens behaviour triggers bite injuries, we studied childrens physical distance to an object and the role of smell and mobility of an object on childrens facial proximity (leaning in) behaviour. We tested this with novel objects and toy animals in children aged 4, 5 and 6 years. Children showed intrusive facial proximity especially with moving items (eg, animates/ toy animals) or novel items. Children under the age of 5 years showed significantly more proximity behaviours than older children. In addition, we also gathered first evidence that children show clear leaning in behaviour with small animals. Thus, we can now make parents aware of younger childrens intrusive inspection behaviour, integrate this knowledge in prevention messages and contribute to reduction in bite injuries, especially to childrens faces.