Cardiac and behavioral reactions to strangers were measured in 5-, and 9-month-olds. Results indicate that: (1) behavioral differences between 5- and 9-month-olds are reflected in heart rate differences, (2) there are differences in heart rate but not behaviors when mothers are absent, and (3) heart rate response is linked to affective expression.…

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)

Investigates psychophysiological reactions of 60 women to an infant's cry and to a control sound. The 30-second pain cry evoked greater cardiac and electrodermal activity than did the control stimulus, although selected groups varied in the nature and extent of their reactions. Both maternal state and experience with infants affected reactions.…

To determine whether heart rate increase can be attributed to increased sucking amplitude for sweeter fluids, sucking and heart rate of 20 full-term infants were studied. (MP)

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…

Classified fetuses as accelerators or decelerators based on intrapartum fetal heart rate (FHR). Explored the relationship of the classification with gestational age and neonatal behavior in clinically healthy neonates to provide an empirical basis for using FHR in the study of infant behavior. Subjects were 48 "healthy term" or…

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…

Summarizes study findings related to the effects of continuous monotonous stimulation on sleep and its physiological parameters in early infancy. (ED)

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)