[Show abstract][Hide abstract] ABSTRACT: Premature infants are at risk of adverse developmental outcomes even with no demonstrable neurological damage. Neonatal physiological measures that can serve as indicators of later development are therefore important for early evaluation and intervention.
We followed the development of 51 low birth weight, premature infants across the first 2 years. Mean systolic cerebral blood flow velocity (CBFV) in the left and right middle cerebral arteries was measured at 37 weeks gestational age, neurobehavioral maturation was assessed with the Neonatal Behavior Assessment Scales (NBAS), and cognitive development was evaluated at 6, 12, and 24 months.
Different patterns emerged for CBFV in the right versus left middle cerebral artery. Greater absolute values of right systolic CBFV were related to poorer performance on the habituation and orientation scales of the NBAS, whereas greater left systolic CBFV absolute values were related to better Mental Development Index (MDI) scores at 24 months. Right systolic CBFV asymmetry was related to poor neonatal orientation and low MDI score at 24 months. On the other hand, infants with left systolic CBFV asymmetry showed a more rapid increase in cognitive skills from 12 to 24 months and better cognitive performance at 2 years.
Measurement of systolic CBFV in the neonatal period may assist in identifying infants at risk of poor developmental outcome.
[Show abstract][Hide abstract] ABSTRACT: In two experiments we examined the effects of human contact and vagal regulation on newborns' pain reactivity and visual attention. Baseline cardiac vagal tone was measured during quiet sleep and during the experiment, and vagal withdrawal was indexed as change in vagal tone from baseline to pain (study 1) or attention (study 2). In study 1, 62 healthy newborns were videotaped during a heel-prick procedure and pain reactivity was assessed from micro-level coding of facial expressions, cry behavior, and body movements. Infants were randomly assigned to a contact condition, held by a female assistant, or a no contact condition, on an infant-seat in a similar angle. In study 2, 62 additional healthy newborns, randomly assigned to contact and noncontact conditions, were presented with 2 visual stimuli for a 60 s familiarization period, which were then paired with a novel stimulus. Visual interest, alertness, and novelty preference were coded. Human contact had no effect on the newborns' pain response. Visual attention increased with human contact and newborns in the contact condition looked at the stimuli more frequently, with higher alertness, for longer durations, and had a higher novelty preference. Autonomic reactivity-as indexed by vagal withdrawal-differentiated newborns with intense and mild pain response. Discussion focused on proximity to conspecifics as a contributor to emerging regulatory and adaptive functioning in the human infant.