Electrophysiological responses to auditory novelty in temperamentally different 9‐month‐old infants

Behavioral reactivity to novel stimuli in the first half‐year of life has been identified as a key aspect of early temperament and a significant precursor of approach and withdrawal tendencies to novelty in later infancy and early childhood. The current study examines the neural signatures of reactivity to novel auditory stimuli in 9‐month‐old infants in relation to prior temperamental reactivity. On the basis of the assessment of behavioral reactivity scores at 4 months of age, infants were classified into groups of high negatively reactive and high positively reactive infants. Along with an unselected control group, these groups of temperamentally different infants were given a three‐stimulus auditory oddball task at 9 months of age which employed frequent standard and infrequent deviant tones as well as a set of complex novel sounds. In comparison to high positively reactive and control infants, high negatively reactive infants displayed increased amplitude of a positive slow wave in the ERP response to deviant tones compared to standard tones. In contrast, high positively reactive infants showed a larger novelty P3 to the complex novel sounds. Results are discussed in terms of optimal levels of novelty for temperamentally different infants.     

The relation between 3‐ and 15‐month olds' cry vocalizations and their mothers' affective involvement during inoculation

This study examined if infant immunization distress is related to their mothers' affective involvement prior to the injection. The duration of infant cry vocalizations and the amount of maternal behaviour before and after the syringe injection were observed in 18 mother–infant dyads, of whom nine comprised 3‐month‐old and nine 15‐month‐old infants. The maternal behaviour was scored in terms of various soothing strategies used to calm infants in distress. Infant cry duration, in both the 3‐ and the 15‐month olds, was associated with amount of maternal eye‐gaze before the injection. For the 15‐month olds, also face‐to‐face contact and rocking the infant was associated with more crying. Even though the small scale of the study warrants some caution in the interpretation, the overall findings suggest that young infants have a referential understanding of caregiver affective involvement prior to a stressor. Copyright © 2007 John Wiley & Sons, Ltd.     

Early manifestations of childhood depression: influences of infant temperament and parental depressive symptoms

In this longitudinal study, 83 parents of infants between 3 and 12 months completed questionnaires assessing demographic information, infant temperament, and maternal depression. When these children were at least 18 months of age, parents completed follow‐up questionnaires assessing toddler temperament and depression‐like symptoms. We were primarily interested in the contributions of infant temperament and maternal depression to toddler depressive problems, and the analytic strategy involved controlling for toddler temperament in order to isolate the influence of infancy characteristics. The findings indicated that lower levels of infant regulatory capacity and greater severity of maternal depression were predictive of toddler depression‐like symptoms. Moderator effects of infant temperament were also examined, with the negative affectivity * maternal depression interaction emerging as significant. Follow‐up analyses indicated that the risk for early manifestations of depression was attenuated for children with lower negative affectivity in infancy and parents who reported lower levels of their own depressive symptoms; conversely, children exhibiting higher infant negative emotionality had higher levels of depression‐like symptoms as toddlers, regardless of their parents' level of depression. The present findings further suggest that parental depressive symptoms need not be ‘clinically significant’ to predict toddler affective problems. Copyright © 2008 John Wiley & Sons, Ltd.     

The role of maternal responsiveness in predicting infant affect during the still face paradigm with infants born very low birth weight

There is limited empirical literature addressing infants' response to a standardized stressor with infants born very low birth weight (VLBW). The purpose of this study was to assess the relative strength of maternal responsiveness in predicting infant affect in response to the Still Face (SF) paradigm in a cross‐sectional cohort of ethnically diverse infants born VLBW and their mothers (N = 50; infants 6–8 months old). Infant affect and maternal responsiveness were coded in 1‐s intervals while dyads participated in the SF. In addition, perinatal medical status, developmental status, and infant temperament were assessed. Findings revealed that positive infant affect during and after the SF stressor were strongly associated with baseline infant positive affect and maternal responsiveness at the reunion episode, respectively. In contrast, when predicting negative infant affect during and after the SF stressor, prior infant negative affect was strongly and uniquely significant. Infant positive affect, negative affect, and maternal responsiveness were not significantly associated with gender, infant perinatal medical history, developmental status, or temperament. Future research is warranted to determine how these findings relate to infants' stress reactions in naturalistic settings and if relationship‐focused interventions may reverse infant negative emotionality, enhance positive emotionality, and thereby improve self‐regulation and longer term social and cognitive developmental outcomes in medically at‐risk infants.     

Humour Perception and Creation between Parents and 3‐ to 6‐month‐old Infants

Humour and laughter are universal to the human psychological experience and have serious developmental and evolutionary implications. Despite the early emergence of laughter in infancy, infants have been largely ignored in the humour research and humour has been largely ignored in the infant research. The present study describes the emergence of humour perception and creation in a sample of 20 parent–infant dyads who were followed from ages 3‐to‐ 6 months. The study examined how infants discover that absurd nonverbal behaviour, known as ‘clowning’, is amusing in the context of social engagement with caregivers. Results indicate that parents primarily use clowning when attempting to amuse their infants and pair these behavioural absurdities with affective cues like smiling and laughing. As they got older, infants were more likely to laugh and smile in response to clowning. Infants' ability to create humor via clowning also increased with age, starting with simple shrieks at 3 months to imitating absurd actions by 5 months. These increases are partly potentially explained by accompanying increases in parental smiling, laughing and clowning in response to infant clowning. Future research should employ more diverse samples and experimentally investigate the role of parental affect and social referencing in infants' interpretation of absurd behavior. Copyright © 2011 John Wiley & Sons, Ltd.     

Habituation and novelty detection fNIRS brain responses in 5‐ and 8‐month‐old infants: The Gambia and UK

The first 1,000 days of life are a critical window of vulnerability to exposure to socioeconomic and health challenges (i.e. poverty/undernutrition). The Brain Imaging for Global Health (BRIGHT) project has been established to deliver longitudinal measures of brain development from 0 to 24 months in UK and Gambian infants and to assess the impact of early adversity. Here results from the Habituation‐Novelty Detection (HaND) functional near‐infrared spectroscopy (fNIRS) task at 5 and 8 months are presented (N = 62 UK; N = 115 Gambia). In the UK cohort distinct patterns of habituation and recovery of response to novelty are seen, becoming more robust from 5 to 8 months of age. In The Gambia, an attenuated habituation response is evident: a larger number of trials are required before the response sufficiently suppresses relative to the response during the first presented trials. Furthermore, recovery of response to novelty is not evident at 5 or 8 months of age. As this longitudinal study continues in The Gambia, the parallel collection of socioeconomic, caregiving, health and nutrition data will allow us to stratify how individual trajectories of habituation and recovery of response to novelty associate with different risk factors and adaptive mechanisms in greater depth. Given the increasing interest in the use of neuroimaging methods within global neurocognitive developmental studies, this study provides a novel cross‐culturally appropriate paradigm for the study of brain responses associated with attention and learning mechanisms across early development.     

Cognitive control moderates early childhood temperament in predicting social behavior in 7‐year‐old children: an ERP study

Behavioral inhibition (BI) is a temperament associated with heightened vigilance and fear of novelty in early childhood, and social reticence and increased risk for anxiety problems later in development. However, not all behaviorally inhibited children develop signs of anxiety. One mechanism that might contribute to the variability in developmental trajectories is the recruitment of cognitive‐control resources. The current study measured N2 activation, an ERP (event‐related potential) associated with cognitive control, and modeled source‐space activation (LORETA; Low Resolution Brain Electromagnetic Tomography) at 7 years of age while children performed a go/no‐go task. Activation was estimated for the entire cortex and then exported for four regions of interest: ventromedial prefrontal cortex (VMPFC), ventrolateral prefrontal cortex (VLPFC), dorsal anterior cingulate cortex (dorsal ACC), and dorsal lateral prefrontal cortex (DLPFC). BI was measured in early childhood (ages 2 and 3 years). Anxiety problems and social reticence were measured at 7 years of age to ascertain stability of temperamental style. Results revealed that BI was associated with increased performance accuracy, longer reaction times, greater (more negative) N2 activation, and higher estimated dorsal ACC and DLPFC activation. Furthermore, early BI was only associated with social reticence at age 7 at higher (more negative) levels of N2 activation or higher estimated dorsal ACC or DLPFC activation. Results are discussed in the context of overcontrolled behavior contributing to social reticence and signs of anxiety in middle childhood.     

The relationship between biological and psychosocial risk factors and resting‐state functional connectivity in 2‐month‐old Bangladeshi infants: A feasibility and pilot study

Childhood poverty has been associated with structural and functional alterations in the developing brain. However, poverty does not alter brain development directly, but acts through associated biological or psychosocial risk factors (e.g. malnutrition, family conflict). Yet few studies have investigated risk factors in the context of infant neurodevelopment, and none have done so in low‐resource settings such as Bangladesh, where children are exposed to multiple, severe biological and psychosocial hazards. In this feasibility and pilot study, usable resting‐state fMRI data were acquired in infants from extremely poor (n = 16) and (relatively) more affluent (n = 16) families in Dhaka, Bangladesh. Whole‐brain intrinsic functional connectivity (iFC) was estimated using bilateral seeds in the amygdala, where iFC has shown susceptibility to early life stress, and in sensory areas, which have exhibited less susceptibility to early life hazards. Biological and psychosocial risk factors were examined for associations with iFC. Three resting‐state networks were identified in within‐group brain maps: medial temporal/striatal, visual, and auditory networks. Infants from extremely poor families compared with those from more affluent families exhibited greater (i.e. less negative) iFC in precuneus for amygdala seeds; however, no group differences in iFC were observed for sensory area seeds. Height‐for‐age, a proxy for malnutrition/infection, was not associated with amygdala/precuneus iFC, whereas prenatal family conflict was positively correlated. Findings suggest that it is feasible to conduct infant fMRI studies in low‐resource settings. Challenges and practical steps for successful implementations are discussed.     

Memory in 3‐month‐old infants benefits from a short nap

A broad range of studies demonstrate that sleep has a facilitating role in memory consolidation (see Rasch & Born, 2013 ). Whether sleep‐dependent memory consolidation is also apparent in infants in their first few months of life has not been investigated. We demonstrate that 3‐month‐old infants only remember a cartoon face approximately 1.5–2 hours after its first presentation when a period of sleep followed learning. Furthermore, habituation time, that is, the time to become bored with a stimulus shown repetitively, correlated negatively with the density of infant sleep spindles, implying that processing speed is linked to specific electroencephalographic components of sleep. Our findings show that without a short period of sleep infants have problems remembering a newly seen face, that sleep enhances memory consolidation from a very early age, highlighting the importance of napping in infancy, and that infant sleep spindles may be associated with some aspects of cognitive ability.     

From negative reactivity to empathic responding: Infants high in negative reactivity express more empathy later in development,with the help of regulation

Empathy has great effect on human well‐being, promoting healthy relationships and social competence. Although it is increasingly acknowledged that infants show empathy toward others, individual differences in infants’ empathy from the first year of life have rarely been investigated longitudinally. Here we examined how negative reactivity and regulation, two temperament traits that predict empathic responses in older children and adults, relate to infants’ empathy. Infants were studied at the ages of nine (N = 275) and 18 (N = 301) months (194 infants were studied at both ages). Empathic responses were assessed by infants’ observed reactions to an experimenter's simulated distress. Negative reactivity (fear, sadness, and distress to limitations) and regulation (soothability and effortful control) were assessed by parental reports. Negative reactivity was also examined by infants’ observed reactions to an adult stranger (fear) and during interaction with their mothers (displays of sadness/distress). When examined cross‐sectionally, infants’ fear and distress to limitations associated with self‐distress in response to others’ distress. In contrast, when examined longitudinally, early sadness and distress to limitations, but not fear, associated with later empathic concern and inquisitiveness. Moreover, this longitudinal relation was moderated by infants’ soothability and was evident only for children that had high soothability by the later time‐point. Our findings suggest that infants who at an earlier age show negative reactivity, react later in development with more empathy if they achieve sufficient regulation abilities. By that, the findings stress the developmental nature of temperament–empathy relations during infancy.     

Identity centrality moderates the relationship between acceptance of group‐based stressors and well‐being

Two two‐wave studies were used to examine the proposition that identity centrality enhances the effectiveness of stressor acceptance in the face of group‐based stressors. Study 1 was conducted in newly commencing psychology students (N = 154). Stressor intensity, psychology student identity centrality, and attempted stressor acceptance were measured at two‐time points over 6‐weeks. Study 2 was conducted in a group of early to late career veterinarians (N = 92) and extended Study 1 by assessing stressor frequency as an indicator of the level of demand. Veterinarian identity centrality and stressor acceptance were measured twice over 12‐months. Both studies provided support for the predicted three‐way interaction. Only when Time 1 stressors and identity centrality were both high was stressor acceptance related to a reduction in perceived stressor intensity (Study 1) or burnout symptoms (Study 2) at Time 2. These findings suggest that identity centrality enhances the effectiveness of stressor acceptance for supporting wellbeing and resilience.     

Frontolimbic neural circuitry at 6 months predicts individual differences in joint attention at 9 months

Elucidating the neural basis of joint attention in infancy promises to yield important insights into the development of language and social cognition, and directly informs developmental models of autism. We describe a new method for evaluating responding to joint attention performance in infancy that highlights the 9‐ to 10‐month period as a time interval of maximal individual differences. We then demonstrate that fractional anisotropy in the right uncinate fasciculus, a white matter fiber bundle connecting the amygdala to the ventral‐medial prefrontal cortex and anterior temporal pole, measured in 6‐month‐olds predicts individual differences in responding to joint attention at 9 months of age. The white matter microstructure of the right uncinate was not related to receptive language ability at 9 months. These findings suggest that the development of core nonverbal social communication skills in infancy is largely supported by preceding developments within right lateralized frontotemporal brain systems.     

Maternal sensitivity moderates the impact of prenatal anxiety disorder on infant responses to the still-face procedure

Animal studies have demonstrated the interactive effects of prenatal stress exposure and postnatal rearing style on offspring capacity to manage stress. However, little is known about how parenting quality impacts the association between maternal prenatal anxiety and stress reactivity in human infants. This prospective study examined the impact of prenatal anxiety disorder and maternal caregiving sensitivity on infants’ responses to a standardised interactive stressor (still-face procedure). Eighty-four women completed a clinical interview during pregnancy to assess anxiety symptoms meeting DSM-IV diagnostic criteria. At infant age 7 months, maternal sensitivity to infant distress and infant negative affect were observed and coded during the still-face procedure. Maternal postnatal (concurrent) anxiety and depression were also assessed at this time. Results indicated a negative association between maternal sensitivity to infant distress and infant negative affect responses to the still-face procedure. An unexpected finding was a positive association between parity and infant reactivity. The main effect for sensitivity was qualified by a significant interaction, p < .05, suggesting that the impact of sensitivity was particularly marked among infants of women who experienced an anxiety disorder during pregnancy. This finding is consistent with a cumulative risk model suggesting that maternal prenatal anxiety and quality of maternal care act in concert to shape infant outcomes.     

Temperamental consequences of infant difficultness

Two central issues pertaining to the construct of infant temperamental “difficultness” were investigated in this longitudinal project. First, the cross-time convergent validity of two parent-report measures of temperament was examined. Second, the temperamental consequences of difficultness during infancy were studied by prospectively following children from infancy to adolescence. Additionally, using MANOVA and structural equation modeling, gender comparisons were conducted to determine whether or not the construct of difficultness was similar for males and females. Analyses were based on parent reports (Ns=96−110) of infant difficultness on the Infant Characteristics Questionnaire (ICQ) when children were 18 months of age. The nine temperament dimensions of the New York Longitudinal Study model were also assessed by parent report inventories when children were 2, 3, 3.5, 5, 8, 10, and 12 years old. Results showed no pervasive evidence of gender differences in infant difficultness. Convergent validity between the ICQ and subsequent temperament measures was evidenced by significant cross-time canonical correlations reaching to moderate magnitude and significant bivariate correlations between infant difficultness and specific temperament dimensions. Temperamental difficultness during infancy predicted subsequent adverse temperamental qualities such as unadaptability and negative mood at every age from 2 through 12 years.     

Relations between behavioral reactivity at 4 months and attachment classification at 14 months in a selected sample

Attachment at 14 months of age was examined in a sample of infants who had been selected for high or low levels of positive or negative affective reactivity and motor activity at 4 months of age. The type of early emotional reactivity was not clearly associated with attachment security or insecurity. The proposal of Belsky and Rovine [Belsky, J., & Rovine, M. (1987). Temperament and attachment security in the strange situation: An empirical rapprochement. Child Development, 58, 787–795] that infants classified as B3/B4 or C1/C2 are temperamentally more negatively reactive than those classified as A1/A2 or B1/B2 was supported. Compared with infants who showed high levels of positive affect and infants who scored low on affective reactivity, infants who showed high levels of negative affect in response to stimulation at 4 months of age were significantly more likely to be classified as B3/B4 or C1/C2 in the Strange Situation at 14 months of age. These findings are discussed in the context of prior inconsistent findings about the relations between temperament and groups of attachment sub-classifications. The role of different methods of assessing temperament and the importance of selected samples in clarifying such relations is discussed.     

Infant Predictors of Toddler Effortful Control: A Multi‐method Developmentally Sensitive Approach

Effortful control (EC) is a form of self‐regulation characterized by inhibition of dominant responses in favour of more adaptive subdominant responses. In the present study, temperamental antecedents in infancy were examined in relationship to toddler EC. Parents reported on infant temperament at 6, 8, 10, and 12 months, using the regulatory capacity/orienting (RCO) factor of the Infant Behavior Questionnaire‐Revised. Laboratory indicators of this temperamental construct were also collected at each time point via the Temperament Laboratory Assessment. Relations between changes in temperament across the first year of life and toddler EC (mean age = 22 months) were examined using multilevel modelling. Parent‐reported RCO and the component subscale of cuddliness more specifically were the only temperamental variables that prospectively predicted toddler EC. Copyright © 2016 John Wiley & Sons, Ltd.     

Early childhood cortisol reactivity moderates the effects of parent–child relationship quality on the development of children's temperament in early childhood

Positive parenting has been related both to lower cortisol reactivity and more adaptive temperament traits in children, whereas elevated cortisol reactivity may be related to maladaptive temperament traits, such as higher negative emotionality (NE) and lower positive emotionality (PE). However, no studies have examined whether hypothalamic‐pituitary‐adrenal axis activity, as measured by cortisol reactivity, moderates the effect of the quality of the parent–child relationship on changes in temperament in early childhood. In this study, 126 3‐year‐olds were administered the Laboratory Temperament Assessment Battery (Lab‐TAB; Goldsmith et al., 1995) as a measure of temperamental NE and PE. Salivary cortisol was collected from the child at 4 time points during this task. The primary parent and the child completed the Teaching Tasks battery (Egeland et al., 1995), from which the quality of the relationship was coded. At age 6, children completed the Lab‐TAB again. From age 3 to 6, adjusting for age 3 PE or NE, a better quality relationship with their primary parent predicted decreases in NE for children with elevated cortisol reactivity and predicted increases in PE for children with low cortisol reactivity. Results have implications for our understanding of the interaction of biological stress systems and the parent–child relationship in the development of temperament in childhood.     

Beyond family‐level adversities: Exploring the developmental timing of neighborhood disadvantage effects on the brain

A growing literature suggests that adversity is associated with later altered brain function, particularly within the corticolimbic system that supports emotion processing and salience detection (e.g., amygdala, prefrontal cortex [PFC]). Although neighborhood socioeconomic disadvantage has been shown to predict maladaptive behavioral outcomes, particularly for boys, most of the research linking adversity to corticolimbic function has focused on family‐level adversities. Moreover, although animal models and studies of normative brain development suggest that there may be sensitive periods during which adversity exerts stronger effects on corticolimbic development, little prospective evidence exists in humans. Using two low‐income samples of boys (n = 167; n = 77), Census‐derived neighborhood disadvantage during early childhood, but not adolescence, was uniquely associated with greater amygdala, but not PFC, reactivity to ambiguous neutral faces in adolescence and young adulthood. These associations remained after accounting for several family‐level adversities (e.g., low family income, harsh parenting), highlighting the independent and developmentally specific neural effects of the neighborhood context. Furthermore, in both samples, indicators measuring income and poverty status of neighbors were predictive of amygdala function, suggesting that neighborhood economic resources may be critical to brain development.     

The influence of maternal optimality and infant temperament on parenting stress at 12 months among mothers with substance abuse and psychiatric problems

The present prospective longitudinal study aimed to investigate the long‐term impact of maternal optimality assessed during pregnancy on parenting stress at infant age 12 months. In this study the concept of optimality was utilized to investigate maternal variations regarding resources during pregnancy in relation to later parenting stress, among three different groups of mothers that were recruited from substance abuse treatment, psychiatric outpatient treatment and well‐baby clinics respectively. The influence of infant temperament on parenting stress was also examined. All mothers were interviewed during pregnancy. At 12 months, infant temperament (Colorado Childhood Temperament Inventory; Rowe & Plomin, 1977) and stress in the parent and child domain (Parenting Stress Index; Abidin, 1955) were assessed. Results demonstrated higher levels of parenting stress among mothers in the clinical groups, compared to the non‐clinical group. Furthermore, it was the maternal psychiatric optimality index in combination with child temperament characteristics (child emotionality) that contributed uniquely to stress in the parent domain, while stress in the child domain was significantly associated only with child temperament characteristics (both child emotionality and soothability). The association between maternal psychiatric optimality assessed in pregnancy, infant temperament and parenting stress when the infants were 12 months old, points to the importance of simultaneously addressing the mothers' own psychological distress, and to support positive mother–infant interactions. Each woman's individual optimality profile may be used to display needs of follow‐up in order to prevent enduring effects of non‐optimality on parenting stress.     

Maternal pre‐ and postnatal anxiety and infant temperament. The generation R study

The aim of this study was to investigate whether maternal anxiety that is temporary or chronic during the pre‐ and postnatal period predicts infant temperament. Mothers of 2997 infants in a population‐based birth cohort reported levels of pregnancy‐specific anxiety (Pregnancy Outcome Questionnaire) and general anxiety symptoms (Brief Symptom Inventory) prenatal and at 6 months postnatal. Temperament characteristics were assessed by maternal report using the Infant Behavior Questionnaire—Revised when the infants were 6 months of age. Maternal pregnancy‐specific and general anxiety during the pre‐ and postnatal period were all independently associated with perceived infant temperamental difficulties. Chronically high maternal anxiety predicted the highest perceived infant activity level and negative affectivity. These findings show that different forms of maternal anxiety during both the pre‐ and postnatal period are independently related to perceived temperamental problems in infancy. They also emphasize the significance of chronic maternal anxiety for infant mental health. Copyright © 2009 John Wiley & Sons, Ltd.