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Biomedical subjects

B M Lester

Publications and source records attributed to B M Lester.

At least 55 records · Page 3Linked to original sources
PubMed1986

Effects of atypical patterns of fetal growth on newborn (NBAS) behavior.

Newborn infants who showed anthropometric signs of atypical patterns of fetal growth were compared with infants of appropriate growth on the Neonatal Behavioral Assessment Scale (NBAS) and on recently developed supplementary items. The sample consisted of lower-socioeconomic-status families in San Juan, Puerto Rico, and included teenage and older mothers. Infants with atypical patterns of fetal growth showed lower scores than did infants of appropriate growth on the NBAS orientation, motor, and reflex clusters and on 15 of the 18 supplementary scores. Gestational age was covaried and showed independent effects on 6 items. Differential effects on measures of state and autonomic function were also found when the effects of the ponderal index were held constant. The results suggested that neonatal behavior is related to multiple indices of fetal growth patterns that may indicate early versus late nutritional insult. Supplementary NBAS items do not improve the discriminability of the NBAS but may help explain the basis for observed group differences.

Adolescent↗
PubMed1985

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.

Age Factors↗
PubMed1983

Behavioral and cardiac rhythmicity during mother-father-stranger infant social interaction.

In an effort to understand the temporal organization of infant physiologic and behavioral systems during social interaction with adults, spectral and cross-spectral analyses of infant heart rate and mother-father-stranger-infant behavioral data are described herein for a 3-month-old infant during face-to-face social interaction with her parents and a stranger. This infant's heart rate rhythms were stronger during social interaction with both mother and father than with a stranger. Infant behavioral rhythms were associated with (high coherence) the parents' behavioral rhythms, but not with those of the stranger. Furthermore, infant heart rate and infant behavioral rhythms showed high coherence with all three adults. Although these findings are preliminary, based on a case study and need replication, they generate intriguing hypotheses. This technique of studying the rhythmicity of infant social interaction with spectral analysis suggests that the 3-month-old infant's behavior and heart rate are synchronized during interaction with all three adults; however, the infant and adult behavioral rhythms are synchronous only with mother and father and not with an unfamiliar stranger.

Child Behavior↗
PubMed1982

Regional obstetric anesthesia and newborn behavior: a reanalysis toward synergistic effects.

The Brazelton Neonatal Behavioral Assessment Scale was administered to 54 term, healthy infants on days 1, 2, 3, 4, 5, 7, and 10. Infants were divided into 8 groups of maternal obstetrical medication. A separate drug factor score was computed from 4 variables: time from (1) first and (2) last drug administration to delivery, (3) number of different drugs, and (4) drug administrations. In order to determine the additive effects of drug and other obstetric factors on neonatal behavior, the drug group and drug factor score plus length of labor, parity, and the ponderal index were used in a series of multiple regression analyses to predict Brazelton scale cluster scores on each day. In a second set of multiple regressions, these variables were used to predict the infant's rate of behavioral change as estimated by the slopes of the Brazelton scale cluster scores across the 7 days. The results indicated that the combined effect of the predictor variables significantly explained 10%-28% of the variance in neonatal behavior. It was hypothesized that the effects of low levels of medication are subtle but may be unmasked when medication effects are studied in combination with other factors that may potentiate drug effects.

Alphaprodine↗
PubMed1981

Cultural and biomedical correlates of neonatal behavior.

The Brazelton Neonatal Behavioral Assessment Scale was administered to 24 each Puerto Rican, Black, and Caucasian, 2-day-old, full-term healthy neonates. Comparisons on 8 Brazelton scale summary scores showed that Puerto Rican infants scored lower on habituation, higher on orientation, and higher on maintaining their organization with increasing stimulation than Black and Caucasian infants. Multiple regression analysis showed that the combination of biomedical variables was significantly correlated with 6 of the Brazelton scale summary scores for the Puerto Rican infants, 1 summary score for the Caucasian infants, and none for the Black infants; it revealed population differences with respect to the synergistic effects of biomedical variables on neonatal behavior.

Apgar Score↗
PubMed1981

Analysis of cry features in newborns with differential fetal growth.

This article describes the relation between neonatal cry features and anthropometric indices of fetal growth. Ponderal indices were calculated to characterize 57 2-day-old infants as underweight for length, average weight for length, or overweight for length. Although no differences were found between the cry features of underweight and overweight infants, these infants at the extremes of the distribution of ponderal indices required more stimulation to elicit a pain cry and had a longer latency from the stimulus to cry onset and a higher fundamental frequency in the cry sound than infants with average ponderal indices. Whereas overweight infants cried for shorter amounts of time than average-weight infants, no differences were found in this sample between the underweight and average-weight infants. Test of differences in the variances of the groups paralleled the tests of mean differences. Because these cry features have been used to distinguish infants along a wide continuum of conditions where the functioning of an infant's central nervous system has been impaired or stressed, it was suggested that certain cry features may reflect the risk status of individual infants with anthropometric signs of both retarded and accelerated fetal growth.

Birth Weight↗
PubMed1979

A comparative study of the behavior of Greek neonates.

Three groups of 30 Greek neonates each (an adoptive group from the Metera orphanage, a lower-class group, and a middle-class group) were evaluated at days 1, 5, and 10 after birth using a behavioral scale of 21 items and a neurologic evaluation of 16 items. Behaviors were examined for group differences and group-by-age recovery curves were determined during the first ten days. Significant differences were found in the separate items and items grouped to reflect interactive, motor, and state behavioral dimensions. The adoptive babies at the Metera orphanage generally performed the most poorly. This difference seems not only to reflect intrauterine differences, especially in regard to nutrition, but to point to the likelihood of eliciting less than optimal responses from future environments. The middle-class group had the worst scores on physiologic items and were similar to the Metera babies in having initially depressed interactive, motor, and state behavior. Improvement in these areas over ten days suggested that temporary effects of maternal medication caused the poor scores. The recovery curves of the infants pointed to the important effects of such perinatal variables as maternal medication on early neonatal behavior.

Arousal↗
PubMed1978

Acoustic features and auditory perceptions of the cries of newborns with prenatal and perinatal complications.

This article describes 2 experiments which examine the relation between neonatal cry features and obstetric histories. Experiment 1 shows that 24 clinically healthy, normal newborns who may be at risk due to a high number of prenatal and perinatal complications can be distinguished from 24 low-complications infants by harmonic and durational features of the cry. High-complications infants required more stimulation to elicit the cry, had a longer latency to cry onset, a shorter first cry expiration, a higher cry pitch, and cried less in total time than low-complications infants. In experiment 2, naive adults rated the high-complications infant cries as more aversive, grating sick, urgent, distressing, piercing, discomforting, and arousing than low-complications infant crues. Factor analyses showed that although the low-complications infant cries were described along one dimension of discomfort, a second factor emerged conveying the "sick" nature of the sound of the cry of the high-complications infants. It was suggested that certain cry features may reflect the risk status of the infant.

Adult↗
PubMed1976

A multivariate study of the effects of high-risk factors on performance on the Brazelton Neonatal Assessment Scale.

The Brazelton Neonatal Assessment Scale was administered to 52 newborn infants. A factor analysis revealed 2 main factors, 1 along an attention-orientation dimension, the other relating to temperament arousal. A stepwise multiple linear regression analysis showed that the attention-orientation factor was related to birth weight, age of the mother, and sex and race of the baby. The only variable related to the temperament-arousal factor was 5-min Apgar scor. The study, although exploratory, demonstrates the use of multivariate techniques in the assessment of influences on newborn behavior.

Apgar Score↗
PubMed1976

Spectrum analysis of the cry sounds of well-nourished and malnourished infants.

The cry sounds of 12 well-nourished and 12 malnourished male infants were compared using behavioral and acoustic measures. The cry of the malnourished infant had an initial longer sound, higher pitch, lower amplitude, more arrhythmia, and a longer latency to the next cry sound than the cry of the well-nourished infant. The similarity betweenthe cry of the malnourished infant and the cry of the brain-damaged infant suggested tha malnutrition may affect the regulatory function of the central nervous system. This hypothesis was supported by additional findings which showed that the abnormal cry patterns in the malnourished infants were associated with a low-level orienting response to a pure tone stimulus as measured by the magnitude of heart-rate deceleration.

Acoustic Stimulation↗
PubMed1975

The use of habituation in the study of the effects of infantile malnutrition.

Habituation of the orienting response (OR) was used to assess possible attentional deficits associated with infantile malnutrition. The procedure involved the presentation of 40 trials of a pure tone stimulus to 8 marginally nourished and 8 malnourished 13 1/2-month-old male infants. The results showed that the initial OR to stimulus onset, as measured by the magnitude of cardiac deceleration, was significantly larger in marginally nourished than in malnourished infants. Within-group comparisons revealed that marginally nourished infants showed significant increases in OR magnitude to changes in tonal frequency whereas the malnourished infants did not. The results were taken as evidence of an attentional deficit associated with infantile malnutrition that is likely to interfere with subsequent learning.

Acoustic Stimulation↗