Severity of prenatal cocaine exposure and child language functioning through age seven years: a longitudinal latent growth curve analysis.
ABSTRACT The current study estimates the longitudinal effects of severity of prenatal cocaine exposure on language functioning in an urban sample of full-term African-American children (200 cocaine-exposed, 176 noncocaine-exposed) through age 7 years. The Miami Prenatal Cocaine Study sample was enrolled prospectively at birth, with documentation of prenatal drug exposure status through maternal interview and toxicology assays of maternal and infant urine and infant meconium. Language functioning was measured at ages 3 and 5 years using the Clinical Evaluation of Language Fundamentals--Preschool (CELF-P) and at age 7 years using the Core Language Domain of the NEPSY: A Developmental Neuropsychological Assessment. Longitudinal latent growth curve analyses were used to examine two components of language functioning, a more stable aptitude for language performance and a time-varying trajectory of language development, across the three time points and their relationship to varying levels of prenatal cocaine exposure. Severity of prenatal cocaine exposure was characterized using a latent construct combining maternal self-report of cocaine use during pregnancy by trimesters and maternal and infant bioassays, allowing all available information to be taken into account. The association between severity of exposure and language functioning was examined within a model including factors for fetal growth, gestational age, and IQ as intercorrelated response variables and child's age, gender, and prenatal alcohol, tobacco, and marijuana exposure as covariates. Results indicated that greater severity of prenatal cocaine exposure was associated with greater deficits within the more stable aptitude for language performance (D = -0.071, 95% CI = -0.133, -0.009; p = 0.026). There was no relationship between severity of prenatal cocaine exposure and the time-varying trajectory of language development. The observed cocaine-associated deficit was independent of multiple alternative suspected sources of variation in language performance, including other potential responses to prenatal cocaine exposure, such as child's intellectual functioning, and other birth and postnatal influences, including language stimulation in the home environment.
Article: Developmental outcomes and environmental correlates of very low birthweight, cocaine-exposed infants.[show abstract] [hide abstract]
ABSTRACT: Fetal cocaine exposure may have differentially adverse effects on developmental outcomes of very low birthweight (VLBW) infants. As part of a longitudinal study, 31 cocaine-positive very low birthweight infants, and age, race and socioeconomic status matched VLBW controls enrolled at birth were followed. Neonatal maternal-child interactions, concurrent maternal psychological characteristics and environmental factors conceptualized as important for child outcome were assessed as well as standard developmental outcomes at 3 years. In the neonatal period, cocaine-exposed VLBW infants who remained in maternal custody tended to be rated as less responsive and their mothers as less nurturing, less emotionally available and with a tendency to use more maladaptive coping mechanisms than nonexposed VLBW infants. At follow-up, cocaine-exposed VLBW children were delayed in cognitive, motor and language development compared to controls. Almost half (45%) of the exposed children scored in the range of mental retardation compared to 16% of the comparison VLBW children. The persistent cognitive, motor and language delays of the cocaine-exposed VLBW children, combined with the poorer behavioral interactions of cocaine-using women with their infants in the neonatal period, indicate a need for increased developmental surveillance of cocaine-exposed VLBW infants with a focus on maternal drug treatment and parenting interventions.Early Human Development 10/2001; 64(2):91-103. · 2.05 Impact Factor
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ABSTRACT: Organisms navigating by path integration need to continuously measure their forward movement and their angular orientation with respect to an external reference. How they do it is little understood. Tethered flies at the flight simulator "navigate" in an artificial visual landscape without forward movement. They can return to a previously held orientation if the panorama provides a singularity (landmark) as reference. Surprisingly, in a regularly striped drum without singularities, they can use a temporal cue instead. In this experiment the arena is illuminated with only one color that is either green or blue. The arena is virtually divided into four quadrants. Whenever a quadrant boundary moves past an arbitrary point, the color of the arena light changes. When a fly is heated with one color it acquires a preference for the other one. Subsequently, it avoids the borders toward the potentially 'hot' quadrants even without touching them. The only way to achieve this is by turn integration, that is, by adding and subtracting all the turns it performs once it crosses the border. The color switch defining the border crossing resets the turn integrator, using the orientation of the arena at this moment as reference. In contrast, landmarks or, if it were available, the skylight compass enable the fly to establish by pattern learning any orientation as a reference. If the reference orientation coincides with the desired orientation, that is, if the animal stores the pattern while being oriented toward the goal, it can maintain its orientation without recourse to turn integration (which may be error prone).Learning & Memory 4(4):318-27. · 4.22 Impact Factor
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ABSTRACT: Cross-linguistic similarities and differences in early lexical and grammatical development are reported for 1001 English-speaking children and 386 Italian-speaking children between 1;6 and 2;6. Parents completed the English or Italian versions of the MacArthur Communicative Development Inventory: Words and Sentences, a parent report instrument that provides information about vocabulary size, vocabulary composition and grammatical complexity across this age range. The onset and subsequent growth of nouns, predicates, function words and social terms proved to be quite similar in both languages. No support was found for the prediction that verbs would emerge earlier in Italian, although Italians did produce a higher proportion of social terms, and there were small but intriguing differences in the shape of the growth curve for grammatical function words. A strikingly similar nonlinear relationship between grammatical complexity and vocabulary size was observed in both languages, and examination of the order in which function words are acquired also yielded more similarities than differences. However, a comparison of the longest sentences reported for a subset of children demonstrates large cross-linguistic differences in the amount of morphology that has been acquired in children matched for vocabulary size. Discussion revolves around the interplay between language-specific variations in the input to young children, and universal cognitive and social constraints on language development.Journal of Child Language 03/1999; 26(1):69-111. · 1.41 Impact Factor