Longitudinal predictors of developmental status and social interaction in premature and full-term infants at age two

This investigation involved the longitudinal assessment of 30 mother-preterm and 40 mother-full-term dyads from birth to 2 years of age. Measures of maternal attitudes, maternal perception of the infant, and parental functioning were obtained at 1 and 8 months of infant age. Mother-infant interactions were observed at 4, 8, 12, and 24 months. Infant cognitive, motor, and language development was assessed at 4, 12, and 24 months. Results indicated that by age 2 years, no group differences were apparent on any child development, mother-child interaction, or maternal attitudinal measures; the lone exception was that preterms were significantly poorer in motor skills. This similarity in functioning at age 2 years was in marked contrast to earlier findings of major group differences at 12 months. Correlational and regression analyses indicated that the developmental and social interaction outcomes were predicted by different factors in the two groups; moreover, whereas 40%-60% of the variance in preterm infants' social and cognitive outcomes could be accounted for, only 15%-30% was accounted for in the full-term group. These results are discussed in terms of compensatory mechanisms that may characterize the parenting of high-risk infants, and of the applicability of transactional models of development.     

The rhythmic structure of mother-infant interaction in term and preterm infants

The purpose of this study was to quantify social interaction rhythms in 3- and 5-month-old term and preterm infants and their mothers. Infant-mother dyads were videotaped in a 3-min face-to-face paradigm. For each second of the interaction, separate scores were assigned to infant and mother indicating levels of affective involvement, creating 2 180-sec time series. Spectral and cross-spectral techniques were used to quantify periodicities in each member of the dyad and to estimate the synchrony or coherence of interactional rhythms between each infant and mother. Results showed the existence of periodicities in the behavior of each infant and mother at 3 and 5 months, with most subjects showing spectral peaks between .022 and .10 Hz. Increases from 3 to 5 months in behavioral periodicities were found for infants and mothers as well as for the coherence between infant-mother dyads. Term dyads showed higher coherence than preterm dyads at both 3 and 5 months. Term infants more often led the interaction at both ages. These results were taken as evidence that behavioral periodicities, which may be biologically based, underlie early mother-infant interaction and provide a temporal structure for the organization of cognitive and affective experience. Differences in synchrony between term and preterm infants may explain later reported differences in language between these groups.     

Hospital-based primary prevention strategy in child abuse: a multi-level needs addressment

The purpose of this study was to evaluate a primary prevention effort in child maltreatment, the focus of which was a community-wide endeavor (i.e., subjects were not prescreened for risk potential). Specific components of the planned intervention addressed four causal levels of maltreatment: individual, family, community, and cultural factors. That assessment was intended to build strengths in those parenting areas which are predictive of abusive or neglectful outcomes. Target areas included knowledge of child development, child-rearing attitudes, mother-infant interaction patterns, and parenting skills. A posttest-only control group design was employed. The control postpartum mothers received traditional or routine hospital services; experimental mothers received special in-hospital and after-care services by trained student nurse volunteers. These volunteers functioned in a dual educative/supportive role. Experimental mothers reported more realistic expectations of behavior, embraced more democratic child-rearing principles, providing more verbal stimulation to their infants (reflecting an increased sensitivity), and displayed increased problem-solving abilities.     

Synchrony in mother-infant interactions.

A measure of mother-infant synchrony was developed and used to compare the interactions of mothers with preterm and mothers with full-term infants. Each mother-infant dyad was observed during a standard bottle-feeding session on 3 separate occasions: once prior to hospital discharge and 1 and 3 months after discharge. Synchrony, defined by the correlation between mother and infant behavioral rates during corresponding segments of the observation session, was found to (1) distinguish between preterm and full-term groups at 3 months and (2) successfully predict below-average Home Observation for Measurement of the Environment (HOME) scores at 9 months for dyads in which mother and infant behavioral rates were inversely related. Further analysis identified certain interaction characteristics related to synchromy.     

Early home intervention with low-birth-weight infants and their parents

We investigated the effects of a year-long home intervention with a sample of preterm infants randomly assigned to 1 of 3 groups: a developmental intervention, a parent-infant intervention, and a no-treatment control group. A full-term no-treatment control was also used. Both intervention approaches focused on the parent-child unit, providing training for parents to improve observational skills, emotional support, and information about community resources. However, whereas specific tasks to facilitate the child's development were provided in the developmental intervention group, the quality of the parent-infant interaction was the target for treatment in the other group. All infants were assessed at 4, 8, 12, and 16 months of age corrected for prematurity. The results suggest that although both intervention approaches were effective in modifying some aspects of the home environment and, to a lesser degree, in improving infants' cognitive development, the parent-infant interaction approach seemed to have the greater impact. These findings confirm previous observations regarding the cognitive development of preterm and full-term infants during the first 18 months of life and demonstrate changes in behavior and behavior styles in both pre- and full-term infants as they become older.     

Environmental characteristics of a neonatal intensive-care unit

An increasing number of intervention programs are designed to ameliorate the "sensory deprivation" of hospitalized premature infants. However, observation of the premature infant's hospital environment every 15 min for 5 24-hour periods indicated that acoustic stimuli were clearly audible in over 95% of the observations, infants were handled during more than 10% of the times they were observed, and illumination levels were always sufficiently high to permit easy visibility. Analysis of the nature of this stimulation suggests that premature infants may suffer from an inappropriate pattern rather than an inadequate amount of stimulation.     

Attachment Quality in Very Low-Birthweight Premature Infants in Relation to Maternal Attachment Representations and Neurological Development

Objective. To study the development of attachment in very low-birthweight preterm infants with respect to neurological development and maternal attachment representations. Design. Emotional development in a high-risk sample (N = 79) of very low-birthweight preterm infants (≤ 1,500 g) is reported. The quality of attachment in preterm infants was classified using the Strange Situation Procedure at 14 postnatal months (corrected for prematurity) and was associated with maternal attachment representation assessed with the Adult Attachment Interview at 6 postnatal months. Neurological development at 14 months was taken into account. Results. The distribution of the quality of attachment in preterm infants (60.3% secure, 23.5% insecure - avoidant, 2.9% insecure - ambivalent, 10.3% insecure - disorganized, and 2.9% not classifiable) was comparable with results of studies of term infants. There was no correspondence between maternal representations of attachment and infant quality of attachment. However, neurologically impaired infants were more often insecurely than securely attached. Conclusions. Very low-birthweight preterm infants more often develop an insecure quality of attachment if their neurological outcome is impaired. Therefore, minimizing risk factors for the development of neurological deficits may have a preventive effect both on the somatic and on the emotional development of high-risk infants.     

The relationship between neonatal characteristics and three-month mother-infant interaction in high-risk infants

The behavior of 4 groups of infants--healthy term, healthy preterm, sick preterm, and sick full-term--was assessed in the neonatal period using the Neonatal Behavioral Assessment Scale (NBAS). At 3 months postterm, infants and their mothers were observed and videotaped in a free-play session. Both the NBAS and mother-infant interaction data were analyzed to assess the effects of maturity (term vs. preterm), illness (sick vs. healthy), and their interaction. Results revealed that illness of the infant affected both NBAS performance and maternal behavior during the interaction at 3 moths. Infants who were ill performed poorly on the NBAS orientation dimension; this dimension was found to be significantly associated with maternal and infant behaviors at 3 months. These data demonstrate an association between early infant characteristics and subsequent mother and child interactive behaviors. They also identify postnatal illness as an important influence on the development of the mother-infant dyad.     

Emotion socialization and expressive development in preterm and full-term infants

The expressive behaviors of full-term and preterm infants and their mothers were examined during face-to-face interaction when the infants were approximately 2 1/2, 5, and 7 1/2 months old. Videotapes of the sessions were coded on a second-to-second basis using Izard's discrete emotion coding system. Overall, infants showed a linear increase in positive effect, especially interest and joy, and a corresponding decrease in negative affect, especially pain and knit brow, with age; decrease in negative affect was accounted for largely by the preterm infants. In terms of maternal responses, there was an increase in contingent responding to infant interest expressions and a decrease in contingent responding to infant pain expressions over time, especially in the case of the preterm infant. The data set as a whole was examined further to establish the directionality of influence between mothers and infants in change patterns over time. There was evidence of learning effects in infants as a function of maternal modeling and contingency patterns. Anomalies in maternal responses to preterm infant affect expressions were observed. Mothers of these infants displayed significantly less matching or imitation of their infant's facial expressions, showed random rather than contingent responsiveness to sadness, and a significant ignoring response to infant anger. These differences were attributed to differences in gazing patterns and negative emotion expression in preterm infants. The results are discussed within a framework of emotion socialization that recognizes bidirectionality of influence in the emotional patterns of mothers and infants.     

Intermanual transfer of shapes in preterm human infants from 33 to 34 + 6 weeks postconceptional age

This study investigated the ability of preterm infants to learn an object shape with one hand and discriminate a new shape in the opposite hand (without visual control). Twenty-four preterm infants between 33 and 34 + 6 gestational weeks received a tactile habituation task with either their right or left hand followed by a tactile discrimination task in the opposite hand. The results confirmed that habituation occurred for both shapes and both hands. Infants subsequently held the novel shape longer in the opposite hand. The results reveal that preterm infants are capable of intermanual transfer of shape information. In spite of the immaturity of the corpus callosum in preterm infants, its development seems to be sufficient to allow some transfer of information between both hands.     

Dampening of Adrenocortical Responses during Infancy: Normative Changes and Individual Differences

Changes in cortisol and behavioral responses were examined longitudinally in 83 infants (39 girls, 44 boys) tested at their well-baby exams with inoculations at 2, 4, 6, and 15 months (72 infants completed all testing). Another sample of 2-, 4-, and 6-month-olds ( n = 18 per age) received mock exams without inoculations to determine early developmental changes to the exam procedures. Behavioral distress was coded every 30 sec during the exam, a 5-min inoculation period, and a 20-min recovery period. Salivary cortisol was obtained upon arrival at the clinic and 25 min after the beginning of the inoculation period. To the exam-inoculation procedures, cortisol responses were high at 2 months, decreased significantly between 2 and 4 months, remained comparable between 4 and 6 months, and then declined again between 6 and 15 months. Between 6 and 15 months there was also a decrease in pretest cortisol. By 15 months, significant increases in cortisol from pre- to posttest were no longer observed for most infants. To the exam-only procedures, cortisol responses decreased between 2 and 4 months, and by 4 months most infants failed to show pre- to posttest increases in cortisol. Behavioral distress decreased between 2 and 6 months, but increased again at 15 months. While crying and cortisol were modestly correlated during the 2- to 6-month exam-inoculation procedures, at 15 months no significant correlations were obtained. Behavioral and hormonal reactions thus followed different ontogenetic paths and may provide different information about infant functioning. There was some evidence that the emergence of the circadian rhythm in cortisol might be related to the early decrease in cortisol response.     

Tactile training facilitates infants' ability to reach to targets on the body

This longitudinal study investigated the effect of experience with tactile stimulation on infants' ability to reach to targets on the body, an important adaptive skill. Infants were provided weekly tactile stimulation on eight body locations from 4 to 8 months of age (N = 11), comparing their ability to reach to the body to infants in a control group who did not receive stimulation (N = 10). Infants who received stimulation were more likely to successfully reach targets on the body than controls by 7 months of age. These findings indicate that tactile stimulation facilitates the development of reaching to the body by allowing infants to explore the sensorimotor correlations emerging from the stimulation.     

Preterm infant interaction with the caregiver in the first year of life and competence at age two.

Caregiver-infant interactions were studied for 50 preterm infants and their primary caregivers. Naturalistic observations in the home were made when the infants were 1, 3, and 8 months of age. The social transactions in the first year were related to competence at age 2, thereby extending a previous report showing a moderate association between caregiver-infant interaction and competence at 9 months. The frequency of early social transactions was predictive of the infant's competence at age 2 on the Gesell Developmental Schedules, a sensorimotor scale, a measure of receptive language, and the Bayley Mental Scale. Early social transactions were as predictive of 2-year competence as were caregiver-child transactions at age 2. The study suggests that social transactions as early as 1 month reflect some quality of the relationship between the caregiver and the infant that is important to the child's later mental performance.     

A study of auditory preferences in nonhandicapped infants and infants with Down's syndrome

11 infants with Down's syndrome (MA 9.2 months, CA 12.7 months) and 10 of 11 nonhandicapped infants (MA 9.6 months, CA 9.3 months) demonstrated that they could operate an automated device which enabled them to choose to listen to 1 of a pair of auditory signals. All subjects showed preferential responding. Both groups of infants showed a significant preference for nursery rhymes sung by a female voice rather than played on musical instruments. The infants with Down's syndrome had much longer response durations for the more complex auditory stimuli. The apparatus provides a useful technique for studying language development in both normal and abnormal populations.     

Stable individual differences in developmentally changing preterm infants: a replicated study

In a longitudinal study with the Neurobehavioral Maturity Assessment (NB-MAP), developmental changes and stability of individual differences were assessed in 2 independent samples of preterm infants ranging from 32 weeks conceptional age to term. Individual stability of response was assessed using regression analysis with repeated measures on subjects. The large majority of the functions tested showed highly significant developmental gains with age and highly significant individual stability of performance across age. These findings replicated well across the 2 cohorts. The results are discussed in the light of the neurobiological stage of development of preterm infants during the last 8 weeks prior to term.     

Maternal behavior and attachment in low-birth-weight twins and singletons

Early mother-infant interaction and later security of attachment were assessed for 17 pairs of twins, 5 singleton survivors of twin pairs, and 20 singletons, all low-birth-weight preterm infants. Mother and infant behavior during home observations at 6 weeks and 3, 6, and 9 months was rated on scales developed by Ainsworth and Egeland and Brunquell. A, B, and C patterns of behavior in the Strange Situation conformed to the frequencies predicted from prior full-term samples and were not affected by twinship. However, the proportion of B1 and B4 dyads in the B group significantly exceeded that predicted from normative data. Mothers in B2 and B3 dyads were rated more sensitive and responsive than all others at all 4 observations. Contrary to our expectations that mothers in A and C dyads would receive the lowest ratings, this occurred only at 6 weeks. At later observations mothers in B1 and B4 dyads consistently received the lowest ratings. The discussion focuses on possible reasons for this unexpected finding.     

Development of three-dimensional object completion in infancy

Three-dimensional (3D) object completion was investigated by habituating 4- and 6-month-old infants (n= 24 total) with a computer-generated wedge stimulus that pivoted 15 degrees , providing only a limited view. Two displays, rotating 360 degrees , were then shown: a complete, solid volume and an incomplete, hollow form composed only of the sides seen during habituation. There were no reliable preferences for either test display by 4-month-olds. At 6 months, infants showed a reliable novelty preference for the incomplete test display. Infants in a control group (n= 24) not habituated to the limited-view wedge preferred neither test display. By 6 months, infants may represent simple objects as complete in 3D space despite a limited perspective. Possible mechanisms of development of 3D object completion are discussed.     

Social gaze in preterm infants may act as an early indicator of atypical lateralization

Visual field biases have been identified as markers of atypical lateralization in children with developmental conditions, but this is the first investigation to consider early lateralized gaze behaviors for social stimuli in preterm infants. Eye-tracking methods with 51 preterm (33 male, 92.1% White) and 61 term-born (31 male, 90.1% White) infants aged 8–10 months from Edinburgh, UK, captured the development of visual field biases, comparing gaze behavior to social and non-social stimuli on the left versus right of the screen. Preterm infants showed a significantly reduced interest to social stimuli on the left versus right compared to term children (d = .58). Preterm children exhibit early differential orienting preferences that may be an early indicator of atypical lateralized function.     

Does Infant Carrying Promote Attachment? An Experimental Study of the Effects of Increased Physical Contact on the Development of Attachment

This study was designed to test the hypothesis that increased physical contact, experimentally induced, would promote greater maternal responsiveness and more secure attachment between infant and mother. Low-SES mothers of newborn infants were randomly assigned to an experimental group (n = 23) that received soft baby carriers (more physical contact) or to a control group (n = 26) that received infants seats (less contact). Using a transitional probability analysis of a play session at 31/2 months, it was demonstrated that mothers in the experimental group were more contingently responsive than control mothers to their infants' vocalizations. When the infants were 13 months old, the Ainsworth Strange Situation was administered. Significantly more experimental than control infants were securely attached to their mothers. We infer from these results that for low-income, inner-city mothers, there may be a causal relation between increased physical contact, achieved through early carrying in a soft baby carrier, and subsequent security of attachment between infant and mother.     

Reproductive, perinatal, and environmental factors as predictors of the cognitive and language development of preterm and full-term infants

The accuracy of a risk index based on reproductive and demographic factors to predict subsequent development was tested with 51 full-term and 53 preterm (birth weight less than 1,501 grams) infants. Stanford-Binet IQ and Reynell Language Expression and Comprehension at 3 years were significantly predicted by this risk index. Socioeconomic status, birth order, and, for the preterm group, severity of illness in the perinatal period were the most significant predictors of developmental outcome. The Home Observation for Measurement of the Environment (HOME) scores were significantly correlated, independently of SES and developmental level, with the 3-year Reynell and Stanford-Binet scores for the preterm, but not the full-term, group. Children who were classified as being at risk at 12 months but who had scores in the normal range at 3 years came from families with significantly higher scores on the HOME scale. Children not detected as being at risk in infancy but whose development was delayed at 3 years came from families with lower scores on the HOME scale. The combination system of perinatal, reproductive, and environmental variables allows the detection of infants at risk for subsequent developmental problems.