Observational measures of caregiver's touch behavior in infancy: A systematic review

The caregiver's touch behavior during early infancy is linked to multiple developmental outcomes. However, social touch remains a challenging construct to operationalize, and although observational tools have been a gold standard for measuring touch in caregiver-infant interactions, no systematic review has been conducted before. We followed the PRISMA guidelines and reviewed the literature to describe and classify the main characteristics of the available observational instruments. Of the 3042 publications found, we selected 45 that included an observational measure, and from those we identified 12 instruments. Most of the studies were of infants younger than six months of age and assessed touch in two laboratory tasks: face-to-face interaction and still-face procedure. We identified three approaches for evaluating the caregiver's touch behavior: strictly observational (the observable touch behavior), functional (the functional role of the touch behavior), or mixed (a combination of the previous two). Half of the instruments were classified as functional, 25% as strictly observational, and 25% as mixed. The lack of conceptual and operational uniformity and consistency between instruments is discussed.

Infant massage and brain maturation measured using EEG: A randomised controlled trial

BACKGROUND

Very preterm (VPT) infants develop adverse neurological sequelae from early exposure of the immature brain to the extrauterine environment.

AIMS

To determine the effects of infant massage on brain maturation in low-risk VPT infants.

STUDY DESIGN

A randomised controlled trial of VPT infants, who received standard care or daily massage therapy, administered by the mother, from 34 weeks' to 40 weeks' corrected age (CA).

SUBJECTS

VPT infants (born at 28 weeks to 32 + 6 weeks' gestational age, G.A.) and a healthy at term cohort for comparison.

OUTCOME MEASURES

At term equivalent age (39 weeks' to 42 weeks' CA), EEG was recorded to calculate global relative power (GRP), using power spectral analysis.

RESULTS

Sixty infants were recruited, and EEGs of 25 massage and 20 standard care infants were analysable. There was no difference between groups in primary outcome (beta GRP). There was a significantly higher central alpha relative power measured in the intervention group infants, compared to standard care (SC) group (mean difference = 1.42, 95 % confidence interval (CI): 0.12 to 2.73; p = 0.03). A massage dose effect was shown by a positive correlation between, massage dose and beta, alpha and theta GRP (r = 0.42, 95%CI = 0.12 to 0.64, r = 0.45; 95%CI = 0.16 to 0.66, r = 0.39; 95%CI = 0.10 to 0.62 respectively) and a negative correlation between massage dose and delta GRP (r = -0.41, 95%CI = -0.64 to -0.12), suggesting that a higher dose of massage is associated with more favourable brain maturation.

CONCLUSIONS

Central alpha regional relative power was greater in massaged infants compared to SC group infants, suggesting relatively greater brain maturation in this area. A measurable massage dose effect in favour of greater brain maturation, shows promise for verification in a larger clinical trial.

Spontaneous movements, motor milestones, and temperament of preterm-born infants: Associations with mother-infant attunement

Preterm-born infants and their mothers are at higher risk of showing less attuned interactions. We sought to identify characteristics of preterm-born infants associated with the attunement of mother-infant interactions at the corrected ages of 3-4 months, looking specifically at motor behaviors. We focused on infants' spontaneous movements, achievement of motor milestones, and temperament, which at this young age is often manifested via movement. Sixty preterm-born infants (Mdn_{gestation age in weeks}  = 33, 57.38% male, corrected age Mdn = 14 weeks, interquartile range = 13-16) and their mothers participated. Independent observers rated mother-infant attunement, infants' spontaneous movements, and infants' achievement of motor milestones. Mothers reported infant temperament. We found infants' smooth and fluent movement character and continual fidgety movements were associated with better attunement in terms of higher maternal sensitivity and non-intrusiveness and higher infant responsiveness and involvement. Unexpectedly, infants' achievement of motor milestones was not significantly associated with mother-infant attunement, and maternal reports of infants' higher soothability were associated with lower maternal sensitivity. The study illustrates the value of including the assessment of infants' spontaneous movements, designed for early detection of neurological deficiencies, in research and in clinical practice with parents and preterm-born infants.

The role of maternal touch in the association between SLC6A4 methylation and stress response in very preterm infants

Very preterm (VPT) infants requiring hospitalization in the Neonatal Intensive Care Unit (NICU) are exposed to several stressful procedural experiences. One consequence of NICU-related stress is a birth-to-discharge increased serotonin transporter gene (SLC6A4) methylation that has been associated with poorer stress regulation at 3 months of age. Maternal touch is thought to support infants' stress response, but its role in moderating the effects of SLC6A4 methylation changes is unknown. The aim of this study was to assess the role of maternal touch in moderating the association between increased SLC6A4 methylation and stress response in 3-month-old VPT infants. Twenty-nine dyads were enrolled and at 3 months (age corrected for prematurity), participated in the Face-to-Face Still-Face paradigm to measure infants' stress response (i.e., negative emotionality) and the amount of maternal touch (i.e., dynamic and static). Results showed that low level of maternal touch is associated with high level of negative emotionality during social stress. Furthermore, during NICU stay SLC6A4 methylation in VPT exposed to low level of maternal touch at 3 months was associated with increased negative emotionality. Thus, low levels of maternal static touch can intensify the negative effects of SLC6A4 epigenetic changes on stress response in 3-month-old VPT infants.

Touch-Avoidance and Touch-Seeking in Non-intimate Relationships: The Null Effects of Sightedness

People differ in their touch preferences and in the ways in which they touch others. People who are blind are particularly sensitive to tactile stimulation as a result of sensory compensation, and sense of touch can support their interpersonal communication. In the article presented here, we aimed to explore whether visual status predicts preferences for touch behaviors involving strangers; specifically, we examined touch-seeking and touch-avoidance in non-intimate interpersonal situations. Our study, whose participants comprised 43 individuals with congenital blindness, 53 individuals with adventitious blindness, and 47 sighted controls, showed that visual status does not predict touch-seeking or social touch-avoidance. We also observed similar gender differences in all participating groups, with women avoiding social touch more than men in non-intimate interpersonal situations involving strangers.

Understanding the role and function of maternal touch in children with neurodevelopmental disabilities

During the first years of life, maternal touch can serve different functions including facilitation of child's gaze orientation to faces which is a key precursor for social attention. Although children with neurodevelopmental disability (ND) may have reduced social skills, the role of maternal touch in contributing to gaze orientation to maternal face has not been explored in previous research. In the present study, we investigate the functions of maternal touch in dyads of mothers and children with ND, compared to dyads of children with typical development (TD). Micro-analytic 2-s coding of maternal touch (i.e., affectionate, playful, facilitating, holding, no touch) and children's gaze orientation (i.e., mother-oriented, object-oriented, non-oriented) occurred during 5-minute interactions between mothers and their 12-to-24-month-old ND and TD children. Dyads were paired for children chronological age and sex. Mothers of children with ND used more touch - especially facilitating and holding types -, compared to mothers of TD peers. Children with ND exhibited more non-orientated gaze compared to TD counterparts. Playful touch associated with increased mother-oriented gaze in children with ND, whereas affectionate and holding touch associated with greater mother-oriented gaze in TD children. Findings suggest that specific types of touch support children's attention to social partners.

Social touch during development: Long-term effects on brain and behavior

In this paper, our goal is to explore what is known about the role of social touch during development. We first address the neural substrates of social touch and the role of tactile experience in neural development. We discuss natural variation in early exposure to social touch, followed by a discussion on experimental manipulations of social touch during development and "natural experiments", such as early institutionalization. We then consider the role of other developmental and experiential variables that predict social touch in adults. Throughout, we propose and consider new theoretical models of the role of social touch during development on later behavior and neurobiology.

Touch Processing and Social Behavior in ASD

Abnormal patterns of touch processing have been linked to core symptoms in ASD. This study examined the relation between tactile processing patterns and social problems in 44 children and adolescents with ASD, aged 6-14 (M = 8.39 ± 2.35). Multiple linear regression indicated significant associations between touch processing and social problems. No such relationships were found for social problems and autism severity. Within touch processing, patterns of hyper-responsiveness and hypo-responsiveness best predicted social problems, whereas sensory-seeking did not. These results support that atypical touch processing in individuals with ASD might be contributing to the social problems they present. Moreover, it the need to explore more in depth the contribution of sensory features to the ASD phenotype.

Social touch interacts with infants' learning of auditory patterns

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Infants use intersensory redundancy provided by social touch to learn auditory patterns.

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There is wide variation in the frequency of different patterns of touch from caregivers.

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Less frequent patterns of touch may be more likely to enhance attention and learning.

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The findings suggest that infants track patterns of touch in naturalistic input from caregivers.

Infants’ experiences are defined by the presence of concurrent streams of perceptual information in social environments. Touch from caregivers is an especially pervasive feature of early development. Using three lab experiments and a corpus of naturalistic caregiver-infant interactions, we examined the relevance of touch in supporting infants’ learning of structure in an altogether different modality: audition. In each experiment, infants listened to sequences of sine-wave tones following the same abstract pattern (e.g., ABA or ABB) while receiving time-locked touch sequences from an experimenter that provided either informative or uninformative cues to the pattern (e.g., knee-elbow-knee or knee-elbow-elbow). Results showed that intersensorily redundant touch supported infants’ learning of tone patterns, but learning varied depending on the typicality of touch sequences in infants’ lives. These findings suggest that infants track touch sequences from moment to moment and in aggregate from their caregivers, and use the intersensory redundancy provided by touch to discover patterns in their environment.

Infant massage improves attitudes toward childbearing, maternal satisfaction and pleasure in parenting

The first year of motherhood is a period of growth and adaptation in women's lives with several challenges such as identifying the baby's needs and giving appropriate answers, so that mother and baby get to know each other and form a strong bond. Infant massage is one of the approaches that make an important contribution to the psychological and physiological wellbeing of both baby and mother, helping to form a harmonious relationship. This longitudinal study assessed the benefits of infant massage in the relationship between mother and baby, from birth to 12 months old. Comprising 194 dyads of mothers and their babies the subjects were divided into two groups of 97 dyads each. The Experimental group (EG) comprised mothers who undertook infant massage in a postnatal program with a physical therapist once a week. The Control group (CG) comprised mothers who did not attend any postnatal program and did not perform infant massage. Self-reported measures of attitudes concerning motherhood (CAQ-P), experience associated to motherhood (WBPB), parental satisfaction (PSS) and maternal separation anxiety (MSAS) were evaluated. Results showed that mothers in the experimental group were better adapted to motherhood, had greater confidence in their abilities and received more support from their mothers and husbands than mothers in the control group and were therefore more confident in their abilities. The EG group experienced a stronger relationship with their babies and described it as more positive than mothers in the control group. This longitudinal study suggests that mothers who learned how to perform infant massage had more positive attitudes towards the experience of motherhood in helping to increase the level of knowledge, regulation and proximity in the dyad. These findings can in turn help mothers to develop strategies that enable them to better cope with motherhood.

Multimodal infant-directed communication: how caregivers combine tactile and linguistic cues

Both touch and speech independently have been shown to play an important role in infant development. However, little is known about how they may be combined in the input to the child. We examined the use of touch and speech together by having mothers read their 5-month-olds books about body parts and animals. Results suggest that speech+touch multimodal events are characterized by more exaggerated touch and speech cues. Further, our results suggest that maternal touches are aligned with speech and that mothers tend to touch their infants in locations that are congruent with names of body parts. Thus, our results suggest that tactile cues could potentially aid both infant word segmentation and word learning.

Social Touch Technology: A Survey of Haptic Technology for Social Touch

This survey provides an overview of work on haptic technology for social touch. Social touch has been studied extensively in psychology and neuroscience. With the development of new technologies, it is now possible to engage in social touch at a distance or engage in social touch with artificial social agents. Social touch research has inspired research into technology mediated social touch, and this line of research has found effects similar to actual social touch. The importance of haptic stimulus qualities, multimodal cues, and contextual factors in technology mediated social touch is discussed. This survey is concluded by reflecting on the current state of research into social touch technology, and providing suggestions for future research and applications.

Intimacy in Phone Conversations: Anxiety Reduction for Danish Seniors with Hugvie

There is a lack of physical contact in current telecommunications such as text messaging and Internet access. To challenge the limitation and re-embody telecommunication, researchers have attempted to introduce tactile stimulation to media and developed huggable devices. Previous experiments in Japan showed that a huggable communication technology, i.e., Hugvie decreased stress level of its female users. In the present experiment in Denmark, we aim to investigate (i) whether Hugvie can decrease stress cross-culturally, i.e., Japanese vs. Danish participants (ii), investigate whether gender plays a role in this psychological effect (stress reduction) and (iii) if there is a preference of this type of communication technology (Hugvie vs. a regular telephone). Twenty-nine healthy elderly participated (15 female and 14 male, M = 64.52 years, SD = 5.67) in Jutland, Denmark. The participants filled out questionnaires including State-Trait Anxiety Inventory, NEO Five Factor Inventory (NEO-FFI), and Becks Depression Inventory, had a 15 min conversation via phone or Hugvie and were interviewed afterward. They spoke with an unknown person of opposite gender during the conversation; the same two conversation partners were used during the experiment and the Phone and Hugvie groups were equally balanced. There was no baseline difference between the Hugvie and Phone groups on age or anxiety or depression scores. In the Hugvie group, there was a statistically significant reduction on state anxiety after meeting Hugvie (p = 0.013). The change in state anxiety for the Hugvie group was positively correlated with openness (r = 0.532, p = 0.041) as measured by the NEO-FFI. This indicates that openness to experiences may increase the chances of having an anxiety reduction from being with Hugvie. Based on the results, we see that personality may affect the participants’ engagement and benefits from Hugvie. We discuss the implications of the results and further elaborations.

Does touch massage facilitate recovery after stroke? A study protocol of a randomized controlled trial

BACKGROUND

Despite high quality stroke care, decreased sensorimotor function, anxiety and pain often remain one year after stroke which can lead to impaired health and dependence, as well as higher healthcare costs. Touch massage (TM) has been proven to decrease anxiety and pain, and improve quality of health in other conditions of reduced health, where reduced anxiety seems to be the most pronounced benefit. Thus there are reasons to believe that TM may also reduce anxiety and pain, and improve quality of life after stroke. Further, several studies indicate that somatosensory stimulation can increase sensorimotor function, and it seems feasible to believe that TM could increase independence after stroke. In this study we will evaluate effects of TM after stroke compared to sham treatment.

METHODS

This is a prospective randomized open-labelled control trial with blinded evaluation (PROBE-design). Fifty patients with stroke admitted to stroke units will be randomized (1:1) to either a TM intervention or a non-active transcutaneous electrical nerve stimulation (non-TENS) control group. Ten sessions of 30 min treatments (TM or control) will be administered during two weeks. Assessment of status according to the International Classification of Functioning, Disability and Health (ICF), including body function, activity, and participation. Assessment of body function will include anxiety, pain, and stress response (heart rate variability and salivary cortisol), where anxiety is the primary outcome. Activity will be assessed by means of sensorimotor function and disability, and participation by means of health-related quality of life. Assessments will be made at baseline, after one week of treatment, after two weeks of treatment, and finally a follow-up after two months. The trial has been approved by the Regional Ethical Review Board.

DISCUSSION

TM seems to decrease anxiety and pain, increase health-related quality of life, and improve sensorimotor functions after stroke, but the field is largely unexplored. Considering the documented pleasant effects of massage in general, absence of reported adverse effects, and potential effects in relation to stroke, it is essential to evaluate effects of TM during the sub-acute phase after stroke. The results of this project will hopefully provide important knowledge for evidence-based care.

TRIAL REGISTRATION

ClinicalTrials.gov: NTC01883947.

Epigenetic and Neurodevelopmental Perspectives on Variation in Parenting Behavior

Mother-infant interactions in rodents can be used to explore the biological basis of postnatal parental effects. There is emerging evidence from laboratory studies that variation in early life experiences can induce molecular changes in the developing brain which lead to activation or silencing of genes. These epigenetic effects may account for the stability of the effects of parenting on offspring development and the transmission of parenting from one generation to the next. In this article, we highlight evidence supporting a role for epigenetic mechanisms in the consequences, transmission, and variability in parenting. Although primarily drawn from laboratory studies in rodents, this evidence may also provide some insights into key questions within the study and practice of human parenting. We discuss these questions, highlighting both the challenges and benefits of using translational approaches.

Maternal symptoms of anxiety during pregnancy affect infant neuromotor development: the generation R study

Several studies found that maternal symptoms of anxiety or depression are related to functioning and development of the offspring. Within a population-based study of 2,724 children, we investigated the effect of maternal anxiety or depression on infant neuromotor development. Symptoms of anxiety and depression were measured during pregnancy and after giving birth; infant neuromotor development was assessed by trained research nurses during a home visit at the age of 3 months. The current study showed that mothers who were anxious during pregnancy had an elevated risk of having an infant with non-optimal neuromotor development.

Qualitative study of breastfeeding after childhood sexual assault

Childhood sexual assault (CSA) is a common experience for women. Little research has explored the breastfeeding experience of CSA survivors who successfully breastfeed. The objective of this study is to explore the experience of successful breastfeeding with mothers with a history of CSA. Eleven women are interviewed after responding to a community-based advertisement. The women self-identify as having experienced CSA by a family member. Semistructured interviews are conducted by the author. Interviews are transcribed, coded, and analyzed for themes. Four key themes are identified: enhancement of the mother- baby relationship, validation of the maternal body, splitting of the breasts' dual role as maternal and sexual objects, and exposure and control when breastfeeding in public. Healthcare professionals should be aware of these maternal issues when promoting breastfeeding and counseling breastfeeding women.

The science of interpersonal touch: an overview

Surprisingly little scientific research has been conducted on the topic of interpersonal touch over the years, despite the importance of touch in our everyday social interactions from birth through to adulthood and old age. In this review, we critically evaluate the results of the research on this topic that have emerged from disciplines, such as cognitive and social psychology, neuroscience, and cultural anthropology. We highlight some of the most important advances to have been made in our understanding of this topic: For example, research has shown that interpersonal tactile stimulation provides an effective means of influencing people's social behaviors (such as modulating their tendency to comply with requests, in affecting people's attitudes toward specific services, in creating bonds between couples or groups, and in strengthening romantic relationships), regardless of whether or not the tactile contact itself can be remembered explicitly. What is more, interpersonal touch can be used to communicate emotion in a manner similar to that demonstrated previously in vision and audition. The recent growth of studies investigating the potential introduction of tactile sensations to long-distance communication technologies (by means of mediated or 'virtual' touch) are also reviewed briefly. Finally, we highlight the synergistic effort that will be needed by researchers in different disciplines if we are to develop a more complete understanding of interpersonal touch in the years to come.

The contribution of fetal drug exposure to temperament: potential teratogenic effects on neuropsychiatric risk

BACKGROUND

Preliminary evidence indicates that fetal drug exposure may be associated with alterations in temperament. However, studies often do not dissociate the potential effects of drug exposure from other perinatal or environmental factors that could influence temperament phenotypes.

METHODS

High risk children (n = 120) were followed from birth to 6 months of age to determine the effects of fetal drug exposure on temperament, after controlling for the child's gender, gestational age, medical morbidity, ethnicity, and maltreatment as well as the mother's stress, income adequacy, and quality of caregiving. Methods included medical chart review, questionnaires, and videotapes of mother-child interaction.

RESULTS

Preliminary analyses indicated that fetal drug exposure was associated with both distractibility and intensity of children's responses to the environment at 6 months of age. After adjusting for potentially confounding variables, drug exposure accounted for 12% of the variance in distractibility but was not a significant predictor in the regression model for intensity.

CONCLUSIONS

Findings suggest that drug-exposed children may experience difficulty sustaining their focus of attention and be more easily distracted by environmental stimuli than non-drug-exposed children. Results converge with previous research to implicate cortical hyperarousal, stemming from teratogenic effects on the dopaminergic system during fetal development.

Implications of Timing of Maternal Depressive Symptoms for Early Cognitive and Language Development

: Statistically, women, particularly pregnant women and new mothers, are at heightened risk for depression. The present review describes the current state of the research linking maternal depressed mood and children's cognitive and language development. Exposure to maternal depressive symptoms, whether during the prenatal period, postpartum period, or chronically, has been found to increase children's risk for later cognitive and language difficulties. The present review considers both the timing of maternal depression and the chronicity of mothers' depression on children's risk for cognitive and language delays. Infancy is frequently identified as a sensitive period in which environmental stimulation has the potential to substantially influence children's cognitive and language development. However, children's exposure to chronic maternal depression seems to be associated with more problematic outcomes for children, perhaps because depression interferes with mothers' ability to respond sensitively and consistently over time. Consistent with this expectation, interventions targeting parenting practices of depressed mothers have been found to increase children's cognitive competence during early childhood. The current review provides a synthesis of the current state of the field regarding the association between maternal depression and children's cognitive and language development during early childhood.

Origins of tactile vulnerability in high-risk infants

PURPOSE

This study examined the degree to which birthweight, gestational age, fetal drug exposure, hazardous postnatal medical events, and a mother's predisposition toward touch predicted the likelihood of an infant's tactile vulnerability during nursing care.

SUBJECTS

The convenience sample included 99 hospitalized infants in their second week of life and their mothers.

DESIGN

The design was correlational.

METHODS

A standardized observational assessment was used to code the infant's physiological and behavioral responses to touch during 4 different episodes of nursing care. Chart review was performed to collect information regarding fetal drug exposure, birthweight, gestational age, and postnatal medical events. Mothers completed a questionnaire regarding their own comfort with using touch and being touched.

MEASURES

The Tactile Vulnerability Assessment measured infant reactivity to and tolerance for touch during nursing care. The Postnatal Complications Scale identified hazardous medical conditions and treatments experienced by the infant during the first 2 weeks of life, and the Physical Contact Assessment evaluated a mother's predisposition toward touch.

RESULTS

The number of hazardous postnatal medical events experienced by an infant was the primary predictor of tactile vulnerability, accounting for 28% of the variance in the infant's likelihood of developing hyperarousal and distress from touch during care. Illicit fetal drug exposure and maternal predisposition toward touch were also significant predictors.

CONCLUSIONS

The significant relationship of postnatal medical events to tactile vulnerability suggests that it may be associated with the presence of infant pain or injury to the infant's central nervous system. Symptoms of drug withdrawal and the impact of teratogens on arousal regulation may also be implicated in greater distress from touch by infants. In addition, findings suggest the potential for inherited transmission of a vulnerability to touch. Assessment of infant vulnerability, including discussion with parents about their views of the infant's needs regarding touch, may enhance problem identification and early intervention to reduce infant distress and further medical problems.

The temperament of pre-term, low birth weight infants and its potential biological substrates

Temperament profiles of pre-term, low birth weight (LBW) infants were assessed at 6 months of age using standardized norms from the Revised Infant Temperament Questionnaire (RITQ). The contributions of perinatal risk, ethnicity, and gender to various temperament dimensions were examined. The sample included 152 infants with a mean birth weight of 1687 g and a mean gestational age of 31 weeks. Eighty percent of the infants were classified as having temperaments that were difficult to manage. Irregularity of the infants' biorhythms, slowness in their ability to adapt to changes, and distractibility were the most problematic. Birth weight, gestational age, and gender were not associated with temperament. Perinatal morbidity was related to the temperament dimension of infant persistence, with implications for the infant's attention span and task performance. Euro American infants were rated as more persistent and less intense in emotional expression than were infants of other ethnic groups. Results suggest the need for a more direct assessment of the effects of neurobiological processes on development of temperament phenotypes and for measurement of temperament that is socioculturally appropriate.