Speech and language development in African-American two- year-olds prenatally exposed to cocaine
Little is known regarding the long-term developmental effects of prenatal cocaine exposure, and even less is known about the specific effects, if any, that this drug has on speech and language development. The purpose of this study was to examine the effects of prenatal drug exposure on the language development of 2-year-old African American (AA) children. Specific attention was given to verbal language behavior as it pertains to language acquisition and language variation. To investigate the relationship between speech and language development and prenatal cocaine exposure, data were obtained from two sources. Standardized speech and language tests were administered to determine the subjects' linguistic performance for comparison with a nonexposed control group. Additionally, linguistic functioning was assessed via naturalistic language samples. It was hypothesized that when compared with a matched group of children who had not been exposed to drugs, the exposed group would differ in speech and language behaviors quantitatively as well as qualitatively. An important aim of this study was to describe drug-exposed children's language in accordance with their cultural and linguistic backgrounds. Statistical analysis included two-tailed t tests and ANOVAs for parametric data and chi square analysis for nonparametric data. No significant differences were noted between the two groups on the BSID and SICD-R, Mean Length of Utterance (MLU)/Mean Length of Response (MLR), total number of utterances, number of single word utterances, multiple word utterances, verb relation utterances, word intelligibility, and use of two and three constituents. Significant differences were observed between the groups on the type and frequency of semantic categories expressed in single word utterances, multiple word utterances, verb relation utterances, and coordinated categories. Significant differences were also noted in the use of the morphemes 'on' and irregular past. The groups differed significantly in aspects of semantic development which may be due to prenatal cocaine exposure. However, parent/caregiver case history review and interviews indicated there was a constellation of factors such as poverty, history of middle ear infections, and continued use of abusive substances, which suggests that any noted delays in language may be attributed to these factors and not solely to prenatal cocaine exposure.