Olfaction scaffolds the developing human from neonate to adolescent and beyond

The impact of the olfactory sense is regularly apparent across development. The foetus is bathed in amniotic fluid that conveys the mother’s chemical ecology. Transnatal olfactory continuity between the odours of amniotic fluid and milk assists in the transition to nursing. At the same time, odours emanating from the mammary areas provoke appetitive responses in newborns. Odours experienced from the mother’s diet during breastfeeding, and from practices such as pre-mastication, may assist in the dietary transition at weaning. In parallel, infants are attracted to and recognise their mother’s odours; later, children are able to recognise other kin and peers based on their odours. Familiar odours, such as those of the mother, regulate the child’s emotions, and scaffold perception and learning through non-olfactory senses. During adolescence, individuals become more sensitive to some bodily odours, while the timing of adolescence itself has been speculated to draw from the chemical ecology of the family unit. Odours learnt early in life and within the family niche continue to influence preferences as mate choice becomes relevant. Olfaction thus appears significant in turning on, sustaining and, in cases when mother odour is altered, disturbing adaptive reciprocity between offspring and caregiver during the multiple transitions of development between birth and adolescence

The role of children, social partners and objects triad in children's environment and learning

It is well established that children’s learning is shaped by social partners and by non-social aspects of their environment. However, most work in this field has been based on relatively constrained settings where the experimenter controls the order and duration of children’s experiences. Therefore, the current thesis aimed to explore how children’s learning environments are affected by different features in controlled but relatively unconstrained settings through the triad of child, object and social partner. The first study examined how two-year-old children’s attention to, and exploration of objects were affected by the presence or absence of labels. Between conditions, objects were either handled by children or by their social partner. Within each condition the objects were either labelled or non-labelled. Children looked longer at the objects and at their social partner’s face when the objects were handled by the social partner. Looking at labelled or non-labelled objects did not differ. Lower vocabulary predicted longer looking at the social partner’s face and more eye-gaze switches and fewer eye-gaze switches, and lower vocabulary predicted better label retention when the experimenter handled the objects. Thus, social partner’s actions affect children’s experiences when actively involved during play. The second study examined caregivers’ actions and language while playing with familiar and novel objects with their nine- or 18-month-old child. Overall, the results suggested that object novelty affected caregivers’ interactive and non-interactive actions and infant directed speech (IDS) characteristics (number of words, pitch range, first utterance duration) while playing with their children. Children’s age also affected caregivers’ actions: caregivers of 18-month-old children used more interactive actions compared to caregivers of the younger age group. Children’s receptive vocabularies and caregivers’ educational levels predicted caregivers’ actions and IDS characteristics. Hence, object types, children’s age and individual differences influence caregivers’ actions and language characteristics and consequently children’s experiences and learning input. In the third study caregivers and their two-year-old children played with 3D novel objects in which the perceptual distances between objects were controlled. Caregivers generated sequences in which they handed objects to their child. Caregivers’ object choices were not the same as their children’s preferences (indicated by child’s longer looking time). Agreement between infant’s and caregiver’s object choice was higher for less securely attached children. While caregivers showed a tendency to generate higher to intermediate novelty sequences (i.e. perceptual distances between successive objects) of objects, this result was not systematic. Caregivers of shyer children generated sequences of higher novelty between the objects. Overall, caregivers’ object sequences were not systematic, and they did not choose the objects their children preferred; however, children’s individual characteristics influenced caregivers’ behaviours during play. Overall, children, social partners and objects, as well as individual characteristics, play an important role in the construction of children’s experiences. The manipulation of these features provided evidence regarding the influence these features have on each other and consequently their effect on children’s experiences, which in turn influences children’s learning and development. Exploring these influences provides a deeper understanding of children’s early learning and development throughout their everyday experiences

The development of sex-congruent preference in infancy - a longitudinal study

Gender schematic processing theory suggests that children will use gender knowledge about themselves and others to make 'like me' judgements about others. They will use the behaviour of 'like me' others to create appropriate 'own-sex' schemas which will guide their behaviour. The research presented here examines this main premise of gender schematic processing theory. Because gender schematic processing posits a unitary source for the development of sex-typed behaviour i.e. the development of gender cognitions, the trajectory of development is presumed to be the same for boys and girls. This assumption is also examined in this thesis. The sex-typed preference of sixty infants at 3, 9, and 18 months was studied using measures of duration of attention to simultaneously-presented male/female pictures of peers, toys, and play activities. Self-recognition (thought to be an early manifestation of self-concept) was measured by observing mirror behaviour (rouge test) and through monitoring the infants' preferential looking to their own image paired with that of a same-age, same-sex peer. The infants' gender labelling ability was assessed at eighteen months, and demographic information was collected at each session. The infants showed self-recognition on both measures at eighteen months, but their poor performance at the gender labelling task suggested that their formal understanding of gender identity had not yet developed. The infants as a group did not show sex-typed preferences for attending to peers, or play activities, although same-sex preference was found for male infants in both areas. Despite an apparent lack of gender- related cohnitions, there was a significant sex-congruent preference for toys when the group of infants was tested at eighteen months. The trajectory of development of this sex-typed behaviour was different for male and female infants suggesting that the gender schematic processing model is not adequate in its present form to predict the ontogeny of sex-typed behaviour

Approaches to studying gaze monitoring in nonhuman primates.

This thesis explored the gaze monitoring abilities of monkeys. A review of previous studies indicated that the face is a valuable source of information for nonhuman primates. When viewing faces, nonhuman primates can recognise conspecifics, individuals and emotional expressions. Within the face, the eyes are a particularly salient feature; nonhuman primates are extremely sensitive to the eyes and gaze is an integral component of all primate expressions. However, where another individual is looking potentially allows a primate access to a wealth of information about their environment; another’s visual orientation can indicate important objects or events. It is this informational value of gaze, rather than responses to self-directed gaze, that is the focus of this thesis. Previous research has indicated that nonhuman primates’ responses to gaze are fairly inconsistent across tasks. Therefore, the studies reported here explored monkeys’ responses to gaze within a number of experimental paradigms in order to better evaluate their abilities. Approaches included spontaneous responses to another individual’s visual co-orientation, picture discrimination, object-choice tasks, a competitive task and a computer-based cueing paradigm. The data reported in this thesis are consistent with previous research in this Held. Nonhuman primates spontaneously follow gaze within a simple visual co-orientation paradigm, but they do not readily use gaze as an informational cue within other paradigms, such as the object-choice task. Explanations of this pattern of results are suggested, and mainly focus on the ecological validity of the tasks and general procedural issues. In addition, nonhuman primates do not demonstrate preferential responding to eye gaze, in fact, head orientation seems to be the more salient cue. These findings are not readily accommodated by Baron-Cohen’s (1994) model that proposes that the eyes are the pre-eminent source of information regarding another individuals’ gaze direction. Directions for future research are identified. There is considerable need for further research on a wider range of primate species, and for a consideration o f the ontogeny of behaviours. A more detailed analysis o f the role o f gaze in nonhuman primates’ natural interactions is considered desirable and other paradigms are also suggested

Upper and lower visual field differences : an investigation of the gaze cascade effect

The purpose of the current thesis was to investigate the role of gaze direction, when making preference decisions. Previous research has reported a progressive gaze bias towards the preferred stimuli as participants near a decision, termed the gaze cascade effect (Shimojo, Simion, Shimojo & Scheir, 2003). The gaze cascade effect is strongest during the final 1500 msec prior to decision (Shimojo et al.). Previous eye-tracking research has displayed natural viewing biases towards the upper visual field. However, previous investigations have not investigated the impact of image placement on the gaze cascade effect. Study 1 investigated the impact of presenting stimuli vertically on the gaze cascade effect. Results indicated that natural scanning biases towards the upper visual field impacted the gaze cascade effect. The gaze cascade effect was reliably seen only when the preferred image was presented in the upper visual field. Using vertically paired stimuli study 2 investigated the impact of choice difficulty on the gaze cascade effect. Similar to study 1 the gaze cascade effect was only reliably seen when the preferred image was presented in the upper visual field. Additionally choice difficulty impacted the gaze cascade effect where easy decisions displayed a larger gaze cascade effect than hard decisions. Study 3 investigated if the gaze cascade effect is unique to preference decisions or present during all visual decisions. Judgments of concavity using perceptually ambiguous spheres were used and no gaze cascade effect was observed. Study 3 indicated that the gaze cascade effect is unique to preference decisions. Results of the current experiments indicate the gaze cascade effect is qualified by the spatial layout of the stimuli and choice difficulty. Results of the current experiments are consistent with previous eye-tracking research demonstrating biases towards the upper visual field and offering support for Previc’s theory on how we interact in visual space

Affect-Driven Attention Biases as Animal Welfare Indicators: Review and Methods.

Attention bias describes the differential allocation of attention towards one stimulus compared to others. In humans, this bias can be mediated by the observer's affective state and is implicated in the onset and maintenance of affective disorders such as anxiety. Affect-driven attention biases (ADABs) have also been identified in a few other species. Here, we review the literature on ADABs in animals and discuss their utility as welfare indicators. Despite a limited research effort, several studies have found that negative affective states modulate attention to negative (i.e., threatening) cues. ADABs influenced by positive-valence states have also been documented in animals. We discuss methods for measuring ADAB and conclude that looking time, dot-probe, and emotional spatial cueing paradigms are particularly promising. Research is needed to test them with a wider range of species, investigate attentional scope as an indicator of affect, and explore the possible causative role of attention biases in determining animal wellbeing. Finally, we argue that ADABs might not be best-utilized as indicators of general valence, but instead to reveal specific emotions, motivations, aversions, and preferences. Paying attention to the human literature could facilitate these advances

A tablet computer-assisted motor and language skills training programme to promote communication development in children with autism: development and pilot study

Autism is a heterogenous condition, encompassing many different subtypes and presentations. Of those people with autism who lack communicative speech, some are more skilled at receptive language than their expressive difficulty might suggest. This disparity between what can be spoken and what can be understood correlates with motor and especially oral motor abilities, and thus may be a consequence of limits to oral motor skill. Point OutWords, tablet-based software targeted for this subgroup, builds on autistic perceptual and cognitive strengths to develop manual motor and oral motor skills prerequisite to communication by pointing or speaking. Although typical implementations of user-centred design rely on communicative speech, Point OutWords users were involved as co-creators both directly via their own nonverbal behavioural choices and indirectly via their communication therapists’ reports; resulting features include vectorised, high-contrast graphics, exogenous cues to help capture and maintain attention, customisable reinforcement prompts, and accommodation of open-loop visuomotor control

Development of neural responses to hearing their own name in infants at low and high risk for autism spectrum disorder

The own name is a salient stimulus, used by others to initiate social interaction. Typically developing infants orient towards the sound of their own name and exhibit enhanced event-related potentials (ERP) at 5 months. The lack of orientation to the own name is considered to be one of the earliest signs of autism spectrum disorder (ASD). In this study, we investigated ERPs to hearing the own name in infants at high and low risk for ASD, at 10 and 14 months. We hypothesized that low-risk infants would exhibit enhanced frontal ERP responses to their own name compared to an unfamiliar name, while high-risk infants were expected to show attenuation or absence of this difference in their ERP responses. In contrast to expectations, we did not find enhanced ERPs to own name in the low-risk group. However, the high-risk group exhibited attenuated frontal positive-going activity to their own name compared to an unfamiliar name and compared to the low-risk group, at the age of 14 months. These results suggest that infants at high risk for ASD start to process their own name differently shortly after one year of age, a period when frontal brain development is happening at a fast rate