Attentional processing of infant emotion during late pregnancy and mother–infant relations after birth

The mother–infant relationship has an important influence on maternal mental health and infant development. Evidence suggests that this relationship is enhanced by a mother’s sensitive response towards her infant’s distress. We proposed that attentional processing of infant distress may indicate individual differences in this response. Research also suggests that maternal responses develop during pregnancy. We therefore hypothesised that more sensitive attentional processing of distressed infant stimuli during late pregnancy will be associated with more successful mother–infant relationships. Healthy pregnant women were recruited through community midwives. An established computerised paradigm measured women’s ability to disengage attention from distressed or non-distressed infant faces. From this paradigm, we derived an index of women’s attentional bias towards infant distress. Mother–infant relationships were measured using the postpartum bonding questionnaire (PBQ). A complete case sample of 49 women completed the attentional paradigm during late pregnancy and the PBQ 3–6 months after birth. We found that women who showed greater attentional bias towards infant distress during late pregnancy reported more successful mother–infant relationships. For every 50-ms increase on our measure of attentional bias towards infant distress during late pregnancy, the odds ratio for reporting a higher PBQ score, indicative of a weaker relationship, was 0.43 (95% confidence intervals 0.23–0.81, p = 0.01). The results suggest that women’s basic attentional processing of infant emotion during pregnancy influences their relationships with their infant. In the future, women’s attentional processing of infant emotion could inform early strategies to promote successful mother–infant relationships in vulnerable mothers to be.     

Delusions related to infant and their association with mother–infant interactions in postpartum psychotic disorders

Summary The relationship between mother infant interactions and psychopathology in postpartum psychotic disorders has been recognised as being clinically important, however data in the field is sparse. The current study had two aims – firstly, to study the prevalence and nature of delusions towards the infant among mothers with postpartum onset severe mental illness and secondly, to study the association between delusional symptoms towards the infant and mother infant interactions. 108 consecutive women with onset of severe mental illness in the postpartum, who were admitted to an inpatient psychiatric unit in South India over a two-year period, were systematically assessed for presence of delusions related to the infant, using the Kannada version of the Birmingham Interview for Maternal Mental Health. Fifty-three percent of subjects reported delusions related to the infant, with 34% reporting more than one delusion. Mothers with infant related persecutory delusions were more likely to show affectionate behaviour and had normal competence and caring for baby’s basic needs; however, they were more likely to get disturbed and agitated if separated from the baby. Mothers who had delusions that the baby was a devil or ill fated or someone else’s baby, were more likely to have significant abusive incidents towards the baby. Overall, the mothers who had delusions related to the infant were seen to have more significant abusive incidents and were more likely to be considered unsafe in looking after the baby alone. The study emphasises the need for systematic clinical assessment of psychopathology in mothers with postpartum psychosis.     

Physiological measures of mother–infant interactional synchrony

Mother–infant interactional synchrony has been hypothesized to be crucial for the development of many key neurodevelopmental behaviors in infants, including speech and language. Assessing synchrony is challenging because many interactive behaviors may be subtlety, if at all, observable in overt behaviors. Physiological measures, therefore, may provide valuable physiological/biological markers of mother–infant synchrony. We have developed a multilevel measurement platform to assess physiological synchrony, attention, and vocal congruency during dynamic face-to-face mother–infant interactions. The present investigation was designed to provide preliminary data on its application in a group of 10 mother–infant dyads (20 subjects) ranging in age from 7 to 8.5 months at the time of the experimentation. Respiratory kinematics, heart rate, and vocalization were recorded simultaneously from mothers and infants during nonstructured, face-to-face interactions. Novel statistical methods were used to identify reliable moments of synchrony from cross-correlated, mother–infant respiration and to tag infant attention from heart rate deceleration. Results revealed that attention, vocal contingency, and respiratory synchrony are temporally clustered within the dyad interaction. This temporal alignment is consistent with the notion that biological synchrony provides a supportive platform for infant attention and mother–infant contingent vocalization.     

Bacillus Calmette-Guérin vaccination and infant mortality

When the bacillus Calmette-Guérin (BCG) vaccine was introduced in the 1920s, it was suggested that BCG occasionally had nonspecific beneficial effects on mortality beyond the specific protection against tuberculosis. Considering that BCG has since then become the most used vaccine in the world, surprisingly few studies have been undertaken into the effect of BCG on general mortality and morbidity. Recent studies suggest that BCG has beneficial nontargeted effects on general infant morbidity and mortality in low-income countries, often with the most pronounced effect among girls. These observational findings are supported by early trials in which children were randomized or alternated to BCG vaccination. Furthermore, a BCG scar and a positive tuberculin reaction are related to better survival among BCG-vaccinated children in low-income countries, especially for girls. The findings are not explained by frailty bias, in other words, that healthy children are more likely to receive BCG vaccination. A nonspecific, gender-differential effect of BCG on general infant mortality may have large implications for tuberculosis vaccine research and routine vaccination policy.     

Why do foreign-born blacks have lower infant mortality than native-born blacks? New directions in African-American infant mortality research.

OBJECTIVE: This study focuses attention on maternal nutrition and stress as possible reasons for excess black infant mortality after exploring lower infant mortality for the infants of foreign-born black mothers compared to native-born black mothers. METHODS: All births to non-Hispanic black women in New York City from 1988-1992 were examined and infant mortality for the infants of native-born women was compared to infant mortality for the infants of foreign-born women. RESULTS: Before controlling for potential confounders on the birth certificate, the infants of native-born black women had a greater risk of infant mortality than the infants of foreign-born black women: OR = 1.48 (95% confidence interval [CI] = 1.38, 1.58). After controlling for potential confounders, the infants of native-born black women still had a greater risk of infant mortality than the infants of foreign-born black women: OR(a) = 1.32 (95% Cl = 1.21, 1.43). CONCLUSIONS: Maternal nutrition and stress are possible causes of excess black infant mortality. They should be topics for research and program development.     

Measuring infant memory: Does the ruler matter?

Although the mobile conjugate reinforcement, deferred imitation, and visual attention paradigms are commonly used to test memory processing by infants, there is often debate about the comparability of memory measured by these three procedures. In a series of experiments, we systematically compared 6-month-old infants' performance across all three procedures. Contrary to current claims, measures of memory obtained using the mobile conjugate reinforcement and deferred imitation paradigms were more similar than those obtained using the deferred imitation and visual attention paradigms.     

The functional neuroanatomy of the evolving parent–infant relationship

Infant survival and the development of secure and cooperative relationships are central to the future of the species. In humans, this relies heavily on the evolving early parent–infant social and affective relationship. While much is known about the behavioural and psychological components of this relationship, relatively little is known about the underlying functional neuroanatomy. Affective and social neuroscience has helped to describe the main adult brain networks involved, but has so far engaged very little with developmental findings. In this review, we seek to highlight future avenues for research by providing a coherent framework for describing the parent–infant relationship over the first 18 months. We provide an outline of the evolving nature of the relationship, starting with basic orienting and recognition processes, and culminating in the infant's attainment of higher socio-emotional and cognitive capacities. Key social and affective interactions, such as communication, cooperative play and the establishment of specific attachments propel the development of the parent–infant relationship. We summarise our current knowledge of the developing infant brain in terms of structure and function, and how these relate to the emergent abilities necessary for the formation of a secure and cooperative relationship with parents or other caregivers. Important roles have been found for brain regions including the orbitofrontal, cingulate, and insular cortices in parent–infant interactions, but it has become clear that much more information is needed about the developmental time course and connectivity of these regions.     

Infant–mother and infant–sibling attachment in Zambia

This study, the first in Zambia using the Strange Situation Procedure (SSP) to observe attachment relationships and the “very first” observational study of infant–sibling attachment, examined patterns of infant–mother and infant–sibling attachment, and tested their association. We included siblings who were substantially involved in caregiving activities with their younger siblings. We hypothesized that infants would develop attachment relationships to both mothers and siblings; the majority of infants would be classified as securely attached to both caregivers, and infant–mother and infant–sibling attachment would be unrelated. The sample included 88 low-income families in Lusaka, Zambia (average of 3.5 children; SD = 1.5). The SSP distributions (infant–mother) were 59% secure, 24% avoidant and 17% resistant, and 46% secure, 20% avoidant, 5% resistant and 29% disorganized for three- and four-way classifications, respectively. The infant–sibling classifications were 42% secure, 23% avoidant and 35% resistant, and 35% secure, 23% avoidant, 9% resistant and 33% disorganized for three- and four-way classifications, respectively. Infant–mother and infant–sibling attachment relationships were not associated.     

Modelling and simulation of an infant’s whole body plethysmograph

In this paper, we describe a computational model dedicated to building an apnoea monitoring system for newborn babies. The proposed model is based on whole body plethysmography, which involves non-invasive measurement of lung ventilation indirectly from the pressure deflections generated when a subject breathes inside a chamber of fixed volume (Bert in C R Soc Biol Paris 20:22–23, 1868). The computational model simulates thermal and environmental flow conditions occurring in the neonate chamber, especially steady state flow with heat transfer and carbon dioxide (CO₂) transport during the exhalation phase. This permits the variance of all critical parameters and the analysis of their effects on the distributions of interest. The main objective is to study thermal and air quality comfort conditions under which infants can be monitored for long-term periods. The method deploys computational fluid dynamics techniques and parametric modelling which, by allowing input parameters to be modulated, represent a more efficient and flexible analytical tool than previous experimental techniques. Simulation data reveal that the largest flow rates occur in areas near the openings with slight formation of air recirculation zones; temperature distribution shows signs of stratification, with higher temperatures than the supplied air, CO₂ distribution presents acceptable air quality level and predicted mean vote index affords a relatively acceptable thermal comfort level. This analytical approach can be considered as innovative, and can find a new application in clinical infant apnoea monitoring in a way that allows determination of the optimal location for placing a sensor to detect respiration activity without any contact with the infant’s body, and without any risk, in contrast to available whole body plethysmography techniques previously tested in infants (Fleming et al. in J Appl Physiol 55:1924–1931, 1983).     

Do infant behaviors following immunization predict attachment? An exploratory study

Objectives. The relationship between infant behaviors during routine immunization, pre- and post-needle, and infant attachment was explored. Methods. A total of 130 parent–infant dyads were recruited from a larger longitudinal study and videotaped during routine immunization at 12 months and the Strange Situation Procedure (SSP) at 14 months. Six infant behaviors were coded for 1-minute pre-needle and 3-minutes post-needle. Attachment was operationalized according to the secure/avoidant/resistant/disorganized categories. Results. As expected, none of the pre-needle behaviors predicted attachment. Proximity-seeking post-needle significantly discriminated attachment categorizations. Secure infants were more likely to seek proximity to caregivers post-needle in comparison with avoidant and disorganized infants. Proximity-seeking following immunization was positively correlated with proximity-seeking during the SSP and negatively correlated with avoidance and disorganization during the SSP. Conclusions. Infant proximity-seeking during immunization is associated with attachment security and parallels behaviors observed during the SSP. More research is needed to identify behavioral markers of disorganization.     

Changing mothers’ perception of infant emotion: a pilot study

Cognitive bias modification (CBM) techniques, which experimentally retrain abnormal processing of affective stimuli, are becoming established for various psychiatric disorders. Such techniques have not yet been applied to maternal processing of infant emotion, which is affected by various psychiatric disorders. In a pilot study, mothers of children under 3 years old (n?=?32) were recruited and randomly allocated to one of three training exercises, aiming either to increase or decrease their threshold of perceiving distress in a morphed continuum of 15 infant facial images. Differences between pre- and post-training threshold were analysed between and within subjects. Compared to baseline thresholds, the threshold for perceiving infant distress decreased in the lowered threshold group (mean difference ?1.7 frames, 95 % confidence intervals (CI) ?3.1 to ?0.3, p?=?0.02), increased in the raised threshold group (1.3 frames, 95 % CI 0.6 to 2.1, p?<?0.01) and was unchanged in the control group (0.1 frames, 95 % CI ?0.8 to 1.1, p?=?0.80). Between-group differences were similarly robust in regression models and were not attenuated by potential confounders. The findings suggest that it is possible to change the threshold at which mothers perceive ambiguous infant faces as distressed, either to increase or decrease sensitivity to distress. This small study was intended to provide proof of concept (i.e. that it is possible to alter a mother’s perception of infant distress). Questions remain as to whether the effects persist beyond the immediate experimental session, have an impact on maternal behaviour and could be used in clinical samples to improve maternal sensitivity and child outcomes.     

PREPP: postpartum depression prevention through the mother–infant dyad

Most interventions to prevent postpartum depression (PPD) focus on the mother rather than the mother–infant dyad. As strong relationships between infant sleep and cry behavior and maternal postpartum mood have been demonstrated by previous research, interventions targeted at the dyad may reduce symptoms of PPD. The goal of the current study was to examine the effectiveness of Practical Resources for Effective Postpartum Parenting (PREPP). PREPP is a new PPD prevention protocol that aims to treat women at risk for PPD by promoting maternally mediated behavioral changes in their infants, while also including mother-focused skills. Results of this randomized control trial (RCT) (n?=?54) indicate that this novel, brief intervention was well tolerated and effective in reducing maternal symptoms of anxiety and depression, particularly at 6 weeks postpartum. Additionally, this study found that infants of mothers enrolled in PREPP had fewer bouts of fussing and crying at 6 weeks postpartum than those infants whose mothers were in the Enhanced TAU group. These preliminary results indicate that PREPP has the potential to reduce the incidence of PPD in women at risk and to directly impact the developing mother–child relationship, the mother’s view of her child, and child outcomes.     

Magnesium and thermoregulation. I. Newborn and infant. Is sudden infant death syndrome a magnesium-dependent disease of the transition from chemical to physical thermoregulation?

The sudden infant death syndrome (SIDS) remains a leading cause of death during the first year. The common epidemiological and pathological data which characterize SIDS include the curve for age at death (with 3 months as modal age), the stigmata of early maternal intrauterine injury, the seasonal predominance in winter, and the absence of an adequate cause of death at autopsy. Some data characterize risk factor subgroups: for example low socioeconomic level, environmental pollution, stress, and mistakes in baby care. Symptoms before death may be lacking, they may be common and non-specific, or rarely they may be acute, corresponding to "apparent life-threatening events" (ALTE). SIDS may be a magnesium-dependent disease of the transition from chemical to physical thermoregulation. This theory originates from a synthesis of our present knowledge of SIDS, maternal magnesium status, and thermoregulation in the baby. It is consistent with all the epidemiological and pathological prerequisites characterizing SIDS. It eliminates the hiatus between relatively minor thermal stress and induced lethal thermal stroke. Logical scepticism about the role of an implausible lethal superacute magnesium deficiency is no longer justified with regard to well established chronic marginal magnesium deficiency. Further experimental and clinical research will be interesting, i.e. ex vivo studies on brown adipose tissue (BAT) and magnesium deficiency under various conditions of thermal exposure. But even now the theory leads to three therapeutic consequences: (1) the need to define the importance of magnesium deficiency in diagnosis and treatment of ALTE; (2) an assessment of the use of new techniques of rewarming (i.e. extracorporeal circulation) in hypothermia cases to distinguish cot death from "apparent death"; (3) investigation of the prevention of SIDS with magnesium through a blinded and randomized multicentre prospective cooperative study of magnesium supplementation in pregnant and lactating women, followed not only in the mother, fetus, and neonate at birth, but also through the first year of life.     

Severe disorders of the mother–infant relationship: definitions and frequency

Summary We assessed the frequency of severe disorders of the mother–infant relationship in over 200 mothers referred to services in Birmingham and Christchurch, all of whom were interviewed using the Birmingham Interview for Maternal Mental Health. 10.6% had established rejection and 14.6% threatened rejection of their infants. 28.6% had various degrees of pathological anger, which was severe in 8.3%. Rejection was strongly associated with unwanted pregnancy and lack of interaction with the foetus.     

Sudden infant death syndrome: is it a transepithelial transport disorder?

The first limiting factor of dietary zinc deficiency has been described as a loss of the protective role of zinc against auto-oxidation of membrane sulfhydryl (SH) compounds. It has now been established that the prohormones (nutriuretic peptides) of the intestinal guanylin family are activated extracellularly by conversion of cysteines in the peptide to disulfide bridges. The induction of uroguanylin mRNA is elevated in intestinal zinc deficiency and nutriuretic peptides regulate epithelial transport of salt and water. Nitric oxide (NO) is also a modulator of salt and water transport. The constitutive forms of nitric oxide synthase (cNOS) in neurons and endothelial cells are calcium-dependent. The inducible form of nitric oxide synthase (iNOS) is activated by bacterial entero-toxins and damaged mucosa with NO penetrating the cell and acting directly on guanylate cyclase. The activated receptor-guanylate cyclases initiating the intracellular cycle 3'-5' guanasine monophosphate (cyclic GMP) cascade in target cells results in a flux of chloride and water into the intestinal lumen. Most of the actions of NO are mediated by activation of cyclic GMP. High-altitude pulmonary edema (HAPE) is associated with a defect in transepithelial water transport. It is suggested that dietary zinc, by modulating thiol oxidation to disulfides in guanylin prohormones to active hormones, is associated with salt and water secretion such that the overworked heart in hypoxemia increases the production and release of natriuretic peptides to activate guanylate cyclase receptors in target tissue in sudden infant death syndrome.     

Are cortisol concentrations in human breast milk associated with infant crying?

The present longitudinal study is the first to investigate the association between human breast milk cortisol and infant crying over the first three months of life. Higher concentrations of breast milk cortisol were expected to be differentially associated with fussing and crying in boys and girls. At 2, 6, and 12 weeks of infant age, mothers (N = 70) collected a morning sample of their milk and kept a 3‐day diary to measure infant fussing and crying. Cortisol was extracted and quantified from milk samples. Results showed that breast milk cortisol concentrations increased from 2 weeks through 12 weeks of infant age. Milk cortisol was unrelated to the total duration, frequency, and bout length of infant fussing and crying for both boys and girls. Directions for future research aiming to extend our knowledge on the biology of milk cortisol in relation to infant behavior and development are discussed.     

The development of infant upright posture: sway less or sway differently?

Postural control is an important factor for early motor development; however, compared with adults, little is known about how infants control their unperturbed upright posture. This lack of knowledge, particularly with respect to spatial and temporal characteristics of infants’ unperturbed independent standing, represents a significant gap in the understanding of human postural control and its development. Therefore, our first analysis offers a thorough longitudinal characterization of infants’ quiet stance through the 9 months following the onset of independent walking. Second, we examined the influence of sensory-mechanical context, light touch contact, on infants’ postural control. Nine typically developing infants were tested monthly as they stood on a small pedestal either independently or with the right hand lightly touching a stationary contact surface. In addition to the longitudinal study design, an age-constant sample was analyzed to verify the influence of walking experience in infant postural development without the confounding effect of chronological age. Center of pressure excursions were recorded and characterized by distance-related, velocity, and frequency domain measures. The results indicated that, with increasing experience in the upright, as indexed by walk age, infants’ postural sway exhibited shifts in rate-related characteristics toward lower frequency and slower, less variable velocity oscillations without changing the spatial characteristics of sway. Additional touch contact stabilized infants’ postural sway as revealed by decrease in sway position variance, amplitude, and area as well as lower frequency and velocity. These results were confirmed by the age-constant analysis. Taken together, our findings suggest that instead of progressively reducing the sway magnitude, infants sway differently with increasing upright experience or with additional somatosensory information. These differences suggest that early development of upright stance, particularly as it relates to increasing postural and locomotor experience, involves a refinement of sensorimotor dynamics that enhances estimation of self-motion for controlling upright stance.     

Does infant memory expression reflect age at encoding or age at retrieval?

Do human infants express a memory acquired earlier in ontogeny in a manner appropriate to their age at encoding or their age at the time of retrieval? To answer this, we exploited the fact that retention is highly context dependent at 6 months but not at 8–9 months of age. Six‐month‐olds learned an operant response in one context, and their memory was maintained by monthly reinstatements in the original context. At 8 or 9 months of age, 1 month after the last (or only) reinstatement, infants were tested in either the same or a different context. During testing, infants' retention was no longer context dependent; rather, they responded robustly in both test contexts. These results revealed that infants expressed a memory acquired when they were younger in a manner appropriate to their test age. They were interpreted in terms of changes in the functional significance of context before and after infants self‐locomote. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 283–291, 2003.     

Intra-alveolar haemorrhage in sudden infant death syndrome: a cause for concern?

BACKGROUND: The "Back to Sleep" campaign in 1991 resulted in a dramatic decrease in the incidence of sudden infant death syndrome (SIDS). The proportion of presumed SIDS deaths being actually suspicious deaths from airway obstruction is likely to have become relatively greater. There is usually little pathological evidence to suggest smothering, but intra-alveolar haemorrhage appears to be more prominent in cases where interference with the airway is suspected. AIM: To attempt to quantify intra-alveolar haemorrhage to see whether it could be used as a marker to distinguish between smothering/overlaying and SIDS. METHODS: Intra-alveolar haemorrhage was quantified using digital image analysis on haematoxylin/eosin stained sections taken from the lungs of 62 consecutive infants who had died suddenly and unexpectedly. Cases were initially classified according to the original cause of death. After quantitation, the case histories were critically reviewed. Three pathologists independently made microscopic assessments of the degree of intra-alveolar haemorrhage in the first 24 cases to see whether these accurately reflected the quantitative results. RESULTS: 73% of those infants with a history suggesting possible involuntary overlaying and 45% of those with a history suspicious of smothering had significant intra-alveolar haemorrhage (> 5% of total lung surface area assessed). From the history, the cause of death in 11 cases initially classified as SIDS would better have been given as "Unascertained." Simple microscopic assessments underestimated the true extent of the haemorrhage in 33% (8/24). CONCLUSIONS: If a moderate degree (at least 5%) of pulmonary parenchymal haemorrhage is observed, this may be an indicator of airway obstruction for a significant period, either from overlaying or possibly smothering. The diagnosis of SIDS may be being used inappropriately in such cases.