Browsing by Author "Schuetze, Pamela"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Detection by adults of differences in the duration of pauses in infant cries
    Schuetze, Pamela (Virginia Tech, 1993)
    Crying is the primary source of distal communication through which newborn and young infants’ needs are related to the caregiving environment and, as such, this social behavior is vital to the survival and development of the infant. Recently, a series of experimental studies has begun to isolate the effects of specific durational components of crying on adults’ perceptions of infant cries. These studies have found the duration of pauses within and between cries to be perceptually salient features, however, the point at which adults were able to detect changes in the duration of the pauses was not addressed. Seventy-five introductory psychology students participated in three experiments designed to determine Difference Thresholds for the point at which manipulations in the durations of pauses before and after the inspiration in infant cries were detectable by the adult listener. The Difference Threshold for the pause before the inspiration (PBI) with the duration of the pause after the inspiration (PAI) held constant was an increase of 354.18% in the duration of the PBI. Difference Thresholds for increases and decreases in the duration of the PAI were 58.53% and -61.91%, respectively. For increases and decreases in the duration of the PAI with a perceptibly longer PBI, Difference Thresholds were 39.82% and -57.6%, respectively. The Difference Threshold for an increase in the duration of the PBI with a perceptibly shorter duration of the PAI was 420.06% and the Difference Threshold for a decrease in the duration of the PBI with a perceptibly longer duration of the PAI was 485.61%. Results provided the first known experimental evidence of the point at which changes in the durations of pauses before and after the inspiration in infant crying are detectable by adult listeners.
  • Thumbnail Image
    Relation between reported maternal caffeine consumption during pregnancy and neonatal state and heart rate
    Schuetze, Pamela (Virginia Tech, 1995)
    The prenatal period is a time of rapid development during which the fetus adapts to a wide range of experiences that may alter the infant’s developmental course. These experiences include exposure to conditions such as maternal stress, disease and the ingestion of a wide range of drugs. While great attention has focused, recently, on the effects of prenatal exposure to such drugs as cocaine and alcohol on newborn behavior, little is known about the effects of prenatal exposure to caffeine. Despite the widespread consumption of caffeine by mothers during pregnancy, recent investigations have suggested that caffeine may indeed function as a physical and behavioral teratogen. In addition to consistent findings of adverse physical outcomes such as prematurity and fetal growth retardation in both animals and humans, adverse effects of maternal caffeine consumption during pregnancy on behavioral development in the fetus have also been suggested by both comparative and human studies. For example, assessment of rodents prenatally exposed to caffeine generally show behavioral patterns of increased activity. Studies with humans using the Neonatal Behavioral Assessment Scale (NBAS) have shown that maternal caffeine consumption is related to differences in the ability of infants exposed to caffeine to regulate their level of arousal. The purpose of this study was to explore the relation between prenatal exposure to caffeine and newborn regulation of arousal, as measured by variations in neonatal heart rate and behavioral state. The heart rates and behavioral states of 50 healthy, full-term one to two-day-old neonates were assessed every 30 seconds for one hour between feedings. Measures of fetal growth and dysmorphology were also collected for each infant. Mothers were then interviewed about their caffeine consumption during pregnancy. When maternal nicotine and alcohol use during pregnancy were statistically controlled, results showed that infants who were prenatally exposed to higher amounts of caffeine had higher heart rates, both overall and during quiet and active sleep. In addition, these infants had experienced a higher number of obstetrical complications and were more likely to be from a lower socioeconomic background than infants prenatally exposed to smaller amounts of caffeine. These findings suggest that maternal caffeine consumption during pregnancy is related to altered levels of arousal among exposed infants. Since heart rate is an indicator of autonomic nervous system functioning, heavier maternal caffeine consumption during pregnancy may have subtle effects on nervous system (NS) development among exposed infants. These observed behavioral outcomes may, in turn, have long-term consequences for social and cognitive development.