Physical contact in parent-infant relationship and its effect on fostering a feeling of safety

Maternal separation as early-life stress: Mechanisms of neuropsychiatric disorders and inspiration for neonatal care

The establishment of positive early parent-infant relationships provide essential nourishment and social stimulation for newborns. During the early stages of postnatal brain development, events such as synaptogenesis, neuronal maturation and glial differentiation occur in a highly coordinated manner. Maternal separation, as an early-life stress introducer, can disrupt the formation of parent-child bonds and exert long-term adverse effects throughout life. When offspring are exposed to maternal separation, the body regulates the stress of maternal separation through multiple mechanisms, including neuroinflammatory responses, neuroendocrinology, and neuronal electrical activity. In adulthood, early maternal separation has long-term effects, such as the induction of neuropsychiatric disorders such as anxiety, depression, and cognitive dysfunction. This review summarized the application of maternal separation models and the mechanisms of stress system response in neuropsychiatric disorders, serving as both a reminder and inspiration for approaches to improve neonatal care, "from bench to bedside".

Infant neural sensitivity to affective touch is associated with maternal postpartum depression

Classic attachment theory emphasizes the sensitivity of the parent to perceive and appropriately respond to the infant's cues. However, parent-child attachment is a dyadic interaction that is also dependent upon the sensitivity of the child to the early caregiving environment. Individual differences in infant sensitivity to parental cues is likely shaped by both the early caregiving environment as well as the infant's neurobiology, such as perceptual sensitivity to social stimuli. Here, we investigated associations between maternal postpartum depression and infant neurological sensitivity to affective touch using brain signal entropy - a metric of the brain's moment-to-moment variability related to signal processing. We recruited two independent samples of infants aged 0-5 months. In Sample 1 (n = 79), we found increased levels of maternal postpartum depression were associated with diminished perceptual sensitivity - i.e. lower entropy - to affective tactile stimulation specifically within the primary somatosensory cortex. In Sample 2 (n = 36), we replicated this finding and showed that this effect was not related to characteristics of the touch administered during the experiment. These results suggest that decreased affective touch early in life - a common consequence of postpartum depression - likely impacts the infant's perceptual sensitivity to affective touch and ultimately the formation of experience-dependent neural networks that support the successful formation of attachment relationships.

Infant neural sensitivity to affective touch is associated with maternal postpartum depression

Classic attachment theory emphasizes the sensitivity of the parent to perceive and appropriately respond to the infant's cues. However, parent-child attachment is a dyadic interaction that is also dependent upon the sensitivity of the child to the early caregiving environment. Individual differences in infant sensitivity to parental cues is likely shaped by both the early caregiving environment as well as the infant's neurobiology, such as perceptual sensitivity to social stimuli. Here, we investigated associations between maternal postpartum depression and infant neurological sensitivity to affective touch using brain signal entropy - a metric of the brain's moment-to-moment variability related to signal processing. We recruited two independent samples of infants aged 0-5 months. In Sample 1 (n=79), we found increased levels of maternal postpartum depression were associated with diminished perceptual sensitivity - i.e. lower entropy - to affective tactile stimulation specifically within the primary somatosensory cortex. In Sample 2 (n=36), we replicated this finding and showed that this effect was not related to characteristics of the touch administered during the experiment. These results suggest that decreased affective touch early in life - a common consequence of postpartum depression - likely impacts the infant's perceptual sensitivity to affective touch and ultimately the formation of experience-dependent neural networks that support the successful formation of attachment relationships.

Insecure Attachment, Oxytocinergic System and C-Tactile Fibers: An Integrative and Translational Pathophysiological Model of Fibromyalgia and Central Sensitivity Syndromes

Although the pathophysiology of fibromyalgia syndrome has been better understood in recent decades, a unified model of its pathogenesis and an effective therapeutic approach are still far from being realized. The main aim of this article will be to delve into the fundamental mechanisms of the pathophysiology of fibromyalgia conceptualized as stress intolerance syndrome. Using the biopsychosocial model of chronic pain syndromes, we will describe the potential role of the attachment system, C-tactile fibers, and oxytocinergic system dysfunction in the pathophysiology of fibromyalgia syndrome and other central sensitivity syndromes. At the end of the article, the therapeutic implications of this new global and translational pathophysiological model will be briefly discussed.

The Role of Play in the Social Development of Grey Seal (Halichoerus grypus) Pups with Comparative Notes on the Harbour Seal (Phoca vitulina)

Juvenile grey seals are known to be highly social, interacting with contact behaviours interpreted as gentle play. However, minimal sociality of pups with their mothers and among weaned pups has been suggested. The present study aimed to observe the natural social interactions of pups to track the early ontogeny of their sociality. Pup behaviour at a salt marsh colony on the east coast of England was video-recorded. Pups interacted with their mothers around suckling bouts and after weaning as they gathered around pools. The records were transcribed to spreadsheets in 30 s time segments to estimate the frequency and co-occurrence of different behaviours. Mother-pup interaction comprised nosing contacts and sometimes contact play, involving one laying the head and fore-flipper over the other. Initial weaned pup encounters involved tentative nosing and defensive splashing, indicating contact shyness. However, socially orientated locomotor play, supine posturing, and exaggerated raising of fore- and hind-flippers led to reduced shyness and pups following one another towards the sea. Archive data on subadult interactions and on harbour seal behaviours were re-analysed. Gentle play-like contact between mother-pup, juvenile, and adult pairs is interpreted here as a universal mode of social bonding, underscoring the social structure of both grey and harbour seals.

Automatic assessment of infant carrying and holding using at-home wearable recordings

Assessing infant carrying and holding (C/H), or physical infant-caregiver interaction, is important for a wide range of contexts in development research. An automated detection and quantification of infant C/H is particularly needed in long term at-home studies where development of infants' neurobehavior is measured using wearable devices. Here, we first developed a phenomenological categorization for physical infant-caregiver interactions to support five different definitions of C/H behaviors. Then, we trained and assessed deep learning-based classifiers for their automatic detection from multi-sensor wearable recordings that were originally used for mobile assessment of infants' motor development. Our results show that an automated C/H detection is feasible at few-second temporal accuracy. With the best C/H definition, the automated detector shows 96% accuracy and 0.56 kappa, which is slightly less than the video-based inter-rater agreement between trained human experts (98% accuracy, 0.77 kappa). The classifier performance varies with C/H definition reflecting the extent to which infants' movements are present in each C/H variant. A systematic benchmarking experiment shows that the widely used actigraphy-based method ignores the normally occurring C/H behaviors. Finally, we show proof-of-concept for the utility of the novel classifier in studying C/H behavior across infant development. Particularly, we show that matching the C/H detections to individuals' gross motor ability discloses novel insights to infant-parent interaction.

Ecological momentary assessment of parent-child attachment via technological devices: A systematic methodological review

Despite extensive research about parent-child attachment using observational and self-report studies, complementary measures are needed to assess this construct objectively with ecological validity, as well as less obtrusiveness and reactivity than traditional measures. This systematic review describes existing technology-based ecologically momentary assessment (EMA) tools examining attachment-related emotions, cognition, and behaviors between the child and its parents. From the study's inception until March 2021, four databases were searched resulting in 11,910 screened citations. Finally, 18 records were included, characterized by a broad variety of assessment tools, sample characteristics, study designs, and attachment outcomes. Technology-based EMA methods comprised audio, video, diary, and sensory assessment modalities, each occuying its methodological niche. When reported, the psychometric properties of the EMA methods were evaluated as very good; however, the included studies' psychometric data was not completely examined. The main attachment outcomes assessed by EMA were emotional and cognitive reactions and actions of the children, the parents, and the dyad. Cognition was rarely assessed using EMA methods. Future research should focus on the complexity of attachment considering different ethnic backgrounds, multiple caregivers' viewpoints, gender aspects, as well as cognitive and dyadic contents in the naturalistic environment.

Infants' sex affects neural responses to affective touch in early infancy

Social touch is closely related to the establishment and maintenance of social bonds in humans, and the sensory brain circuit for gentle brushing is already active soon after birth. Brain development is known to be sexually dimorphic, but the potential effect of sex on brain activation to gentle touch remains unknown. Here, we examined brain activation to gentle skin stroking, a tactile stimulation that resembles affective or social touch, in term-born neonates. Eighteen infants aged 11-36 days, recruited from the FinnBrain Birth Cohort Study, were included in the study. During natural sleep, soft brush strokes were applied to the skin of the right leg during functional magnetic resonance imaging (fMRI) at 3 cm/s velocity. We examined potential differences in brain activation between males (n = 10) and females (n = 8) and found that females had larger blood oxygenation level dependent (BOLD) responses (brushing vs. rest) in bilateral orbitofrontal cortex (OFC), right ventral striatum and bilateral inferior striatum, pons, and cerebellum compared to males. Moreover, the psychophysiological interactions (PPI) analysis, setting the left and right OFC as seed regions, revealed significant differences between males and females. Females exhibited stronger PPI connectivity between the left OFC and posterior cingulate or cuneus. Our work suggests that social touch neural responses are different in male and female neonates, which may have major ramifications for later brain, cognitive, and social development. Finally, many of the sexually dimorphic brain responses were subcortical, not captured by surface-based neuroimaging, indicating that fMRI will be a relevant technique for future studies.

A pilot study of Kangaroo mother care in early essential newborn care in resource-limited areas of China: the facilitators and barriers to implementation

BACKGROUND

Implementation of Kangaroo Mother Care (KMC) in resource-limited areas of China may face unique barriers, such as a lack of resources, geographic location and more traditional culture among others. This qualitative study analyses the facilitators and barriers to implementing KMC in county-level health facilities in resource-limited areas of China for the promotion of KMC on a larger scale.

METHODS

Participants from 4 of the 18 pilot counties where early essential newborn care was implemented through the Safe Neonatal Project and 4 control counties not enrolled in Safe Neonatal Project were selected using purposive sampling. A total of 155 participants were interviewed, including stakeholders of the Safe Neonatal Project such as national maternal health experts, relevant government officials and medical staff. Thematic analysis was used to process and analyse the interview content in order to summarise the facilitators and barriers to implementing KMC.

RESULTS

KMC was accepted in the pilot areas but still faced certain challenges due to institutional regulation, resource provision and the perceptions of health staff, postpartum mothers and their families as well as COVID-19 prevention and control regulations. The facilitators identified were government officials and medical staff acceptance and the incorporation of KMC into routine clinical care. The barriers identified were a lack of dedicated funding and other resources, the present scope of health insurance and KMC cost-sharing mechanism, providers' knowledge and practical abilities, parental awareness, postpartum discomfort, fathers' inadequate involvement, and the impact from COVID-19.

CONCLUSION

The Safe Neonatal Project pilot experience indicated the feasibility of implementing KMC in more areas of China. Optimising institutional regulations, providing necessary supporting resources and enhancing education and training may help to refine the implementation and scale-up of KMC practice in China.

Exploring maternal touch in the infant’s first 18 months of Life: A study on an Italian sample

Affective touch is a crucial component of caregiving in early life and constitutes a key factor with a significant impact on infant later-life outcomes. The Parent-Infant Caregiving Touch Scale (PICTS) allows to quantify and qualify the caregiver's self-perception of touch in the first months of an infant's life. In the current study, we contributed to validation of the PICTS in the Italian language in order to explore whether early maternal touch would be associated with maternal emotional state, maternal history of affective touch experiences throughout the lifespan, and infants' sex and age. Data analyses were run on a sample of 377 Italian mothers (mean age = 33.29; SD = 4.79) participating in an online survey. Confirmatory factor analysis was applied. A three-dimensional structure of PICTS (i.e., stroking, affective communication, and holding) after removing one item out resulted in the best model in our sample. Maternal emotional state did not affect PICTS factor scores while maternal comfort and amount of affective touch experienced during adulthood was significantly associated with the stroking, affective communication, and holding factors. Regarding infants' dimensions, infants' sex and age were not associated with PICTS factor scores. Findings suggest that the PICTS Italian version is a good measurement of caregiver's self-perception of touch in early infancy and that maternal history of touch is associated with a mother's current use of touch.

Children’s age matters: Parental burnout in Chilean families during the COVID-19 pandemic

For families all over the world, going through a pandemic has presented a number of challenges. In particular, social distancing measures involving the closure of schools and day care centers, as well as increasing work hours at home, made parents face very demanding situations. However, we know little about whether parents’ burnout levels are influenced by the age of their children. This study sought to determine whether levels of parental burnout (PB) are higher in families with at least one child under the age of four than in families with older children (5 to 18 years). The second goal was to explore whether having children under 4 years of age moderates the relationship between parental cooperation and PB. A cross-sectional study was conducted with a sample of 651 participants (525 mothers and 126 fathers) since May 18th until August 27th, 2020. The main results showed that child age is a predictor of PB. Besides, having a child aged 0–4 years old moderates the relationship between parental cooperation and PB. Finally, it was found that in cases where there was at least one child under 4 years of age in the family, with one of the partners who worked remotely, the respondent’s PB rose by 7.9 points. The implications of these results with respect to the consideration of children’s ages in the different parental scenarios were discussed.

Neurobiology of Parental Regulation of the Infant and Its Disruption by Trauma Within Attachment

The complex process of regulating physiological functions and homeostasis during external and internal disruptions develops slowly in altricial species, with parental care functioning as a co-regulator of infant physiological and emotional homeostasis. Here, we review our current understanding of the infant's use of parental behaviors for neurobehavioral regulation and its disruption with harsh parental care. Taking a cross-species view, we briefly review the human developmental literature that highlights the importance of the caregiver in scaffolding the child's physiological and emotional regulation, especially under threat and stress. We then use emerging corresponding animal literature within the phylogenetically preserved attachment system to help define neural systems supporting caregiver regulation and its supporting causal mechanism to provide translational bridges to inform causation and mechanisms impossible to define in children. Next, we briefly review animal research highlighting the impact of specific sensory stimuli imbedded in parental care as important for infant physiological and emotion regulation. We then highlight the importance of parental sensory stimuli gaining hedonic value to go beyond simple sensory stimuli to further impact neurobehavioral regulation, with poor quality of care compromising the infant's ability to use these cues for regulation. Clinically, parental regulation of the infant is correlated with later-life neurobehavioral outcome and quality of life. We suggest an understanding of this parental regulation of the infant's immediate neurobehavioral functioning within the context of attachment quality, that may provide insights into the complex processes during early life, initiating the pathway to pathology.

Social touch in the age of computational ethology: Embracing as a multidimensional and complex behaviour

Social affective touch is an important aspect of close relationships in humans. It has been also observed in many non-human primate species. Despite the high relevance of behaviours like embraces for personal wellbeing and mental health, they remain vastly under-investigated in psychology. This may be because psychology often relies on a limited repertoire of behavioural measurements such as error rates and reaction time measurements. These are, however, insufficient to capture the multidimensional complexity of highly interactive dyadic behaviours like embraces. Based on recent advances in computational ethology in animal models, the rapidly emerging field of human computational ethology utilizes an accessible repertoire of machine learning methods to track and quantify complex natural behaviours. We highlight how such techniques can be utilized to investigate social touch and which preliminary conditions, motor aspects and higher-level interactions need to be considered. Ultimately, integration of computational ethology with mobile neuroscience techniques such as ultraportable EEG systems will allow for an ecologically valid investigation of social affective touch in humans that will advance psychological research of emotions.