Four groups of infants, 4 1/2 to 5 1/2 months of age, were presented with repeated speech stimuli which were synthesized exemplars of the sound, "baba," natural exemplars of "baba" or "kaba," or novel syllables on each trial. (RH)

Twice during the neonatal period, the behavioral organization of 42 newborns was assessed by the Neonatal Behavioral Assessment Scale (NBAS), and the newborns' cortisol response to the NBAS procedure was determined. Newborns with low orientation showed a higher increase in cortisol during the NABS than newborns with high orientation. (MDM)

Examined behavioral/physiological responses of 2-month-olds during physical examinations. Found that colic infants cried twice as much, cried more intensely, and were more inconsolable than control infants. Heart rate, vagal tone, and cortisol measures showed no appreciable difference. At home, colic infants displayed a blunted rhythm in cortisol…

Examined visual fixation in 3- to 6-month olds for fit to attentional inertia theory. Found that look duration toward extended audiovisual stimuli had a lognormal distribution. The conditional probability of looking away decreased when look duration increased. Heart rate deceleration accompanied look onset and stimulus changes occurring within…

Examined the sex differences in physiological and behavioral stress reactivity among 36 healthy, full-term neonates after a mildly stressful behavioral assessment procedure. Salivary cortisol, heart rate change, Neonatal Behavior Assessment Scale (NBAS) cluster scores, and behavioral states after the NBAS provided 100% discrimination between male…

Explored relation between temperament and cardiac vagal tone in 12-week olds. Found that infants with higher baseline vagal tone showed fewer negative behaviors in the laboratory and were less disrupted by experimental procedures than infants with lower baselines. Infants who decreased cardiac vagal tone during assessments were rated by mothers as…

Explores whether an empirical classification of healthy fetuses as fetal heart rate accelerators or decelerators would predict birth weight and neonatal behavior scored with the Brazelton Neonatal Behavior Assessment Scale. (Author/RH)

Groups of 7 1/2-month-old infants heard 1 of 8 episodes consisting of no, slight, moderate, or large discrepancy between a habituated standard and a transformed auditory stimulus. Patterns of cardiac deceleration supported the hypothesis that attentiveness is an inverted-U function of the degree of discrepancy between stimulus event and schema.…

Examined fetal heart rate and movement in 31 healthy fetuses from 20 weeks through birth and at age 6 months. Found that more active fetuses were more difficult, unpredictable, unadaptable, and active as infants that were less active fetuses, and that higher fetal heart rate was associated with lower emotional tone, activity level, and…

Investigated infants' reactions to the face-to-face/still-face paradigm. Infants reacted to the still-face with negative affect, a drop in vagal tone, and an increase in heart rate. By contrast, they reacted to the reunion episode with a mixed pattern of positive and negative affect. (HTH)

Baseline and heelstick measures of behavioral state, heart period, vagal tone, and salivary cortisol were obtained from 50 full-term newborns. Mothers completed Rothbart's Infant Behavior Questionnaire when the infants reached six months of age. Greater reactivity to the heelstick was associated with lower scores on the…

The cry sounds of 12 well-nourished and 12 malnourished male infants were compared using behavioral and acoustic measures. (BRT)

Study of children aged 21 to 31 months tentatively concludes: (1)behavioral tendency to be inhibited or uninhibited with unfamiliar people or during unfamiliar events is moderately stable across time and context; and (2)moderately negative relationship exists between behavioral inhibition and heart rate variability, and positive relationship…