Developmental psychobiology
-
The majority of children who are born very preterm escape major impairment, yet more subtle cognitive and attention problems are very common in this population. Previous research has linked infant focused attention during exploratory play to later cognition in children born full-term and preterm. Infant focused attention can be indexed by sustained decreases in heart rate (HR). ⋯ Among the extremely preterm infants born <29 weeks, fewer days on mechanical ventilation, mean longest focus, and greater HR deceleration during focused attention episodes, accounted for 49% of adjusted variance in predicting concurrent MDI. There were no significant associations for later-born gestational age (29-32 weeks) or full-term infants. Among extremely preterm infants who escape major impairment, our findings suggest unique relationships between focused attention, HR deceleration, and developing cognition.
-
Adolescence is characterized as a developmental period of risky decision-making. During this developmental window there is also a marked increase in actual and perceived stress. Acute stress increases risky decision-making in adults, but no research has examined this phenomenon in adolescents. ⋯ Participants visited the laboratory twice: once each when they endorsed a high and low level of stress, where they performed a risky decision-making task and a response inhibition task. In both groups, participants showed greater risky decision-making under high (vs. low) stress conditions but no stress-related effects on response inhibition. The dissociation between decision-making and response inhibition under stress suggests that, across development, individuals show greater vulnerability to contextual influence in decision-making domains.
-
Knowledge of normal development of brain-behavior relations plays an important role in understanding how the plasticity of the nervous system can be used to promote recovery of function following brain damage. Aspects of the other articles in this issue are used in justification of the value of such developmental knowledge. Also, the development of amblyopia and its remediation in adulthood is discussed as a model for developing other techniques for ensuring recovery of function after stroke. Although the articles in this issue establish an excellent context for improving actual recovery of function (rather than compensation for deficits), much still needs to be discovered about how we can use developmental knowledge, along with knowledge of the plasticity of the nervous system, to improve remediation techniques.
-
Cortisol levels were compared in children born preterm at extremely low gestational age (ELGA; 24-28 weeks), very low gestational age (VGLA; 29-32 weeks), and full-term in response to cognitive assessment at 18 months corrected age (CA). Further, we investigated the relationship between maternal interactive behaviors and child internalizing behaviors (rated by the mother) in relation to child cortisol levels. ⋯ Moreover, the pattern of cortisol change was related to internalizing behaviors among ELGA, and to a lesser degree VLGA children. In conclusion, our findings suggest altered programming of the hypothalamic-pituitary-adrenal (HPA) axis in preterm children, as well as their greater sensitivity to environmental context such as maternal interactive behavior.
-
The objective of this study was to determine the consequences for HPA axis functioning among healthy full-term newborns of prenatal treatment with the synthetic glucocorticoid (GC), betamethasone, which is the routine treatment for threatened preterm delivery. Ninety full-term infants were recruited into two study groups (30 betamethasone treated; 60 comparison group matched for GA at birth and sex). ⋯ Further, within the recommended window of betamethasone administration (24-34 gestational weeks), infants exposed to betamethasone earlier in gestation displayed the largest cortisol response to the heel-stick. These data add to accumulating evidence that prenatal exposure to elevated GCs programs the development of the HPA axis.