The next several pages are intended as a "Commentary" on the six target articles bundled together as a Special Issue of the "Journal of Cognition and Development"--literature reviews and research reports all intended to "build bridges" between the study of cognitive development in typical and atypical populations.

Most people have 23 pairs of chromosomes; one set from the mother and one from the father. However, nondisjunction errors during meiosis can lead to a case of trisomy, where there are three rather than two chromosomes. Although such events are not uncommon, they are usually lethal, and account for a high proportion of spontaneous abortions. There…

In mammalian species, behavior begins in utero, hidden within the mother's body. This biological fact has made it difficult to observe or to access fetuses, leaving the beginnings of behavior to the imagination or allowing it to be forgotten or ignored. Such truncation of perspective probably helped many to consider behavioral capabilities first…

More babies of very young mothers (under age 16) die, are medically at risk, and have developmental and educational difficulties than children of older, but still relatively young mothers. Because of the etiology of adolescent pregnancy, the young mother is unlikely to seek comprehensive prenatal care at the first realization of pregnancy. In…

A review of research on the effects of alcohol consumption by pregnant women supports the U.S. Food and Drug Administration's warning about the possible negative effects (learning disabilities, hyperactivity, short attention span, and emotional liability) of children. (Author/CL)

The autistic syndrome is considered in the context of a disorder of brain development. The authors conclude that disruption of developmental loci most probably occurs in the end stages of neuronal development, after migrating neurons have reached their final place in the brain and are elaborating communicative processes. (Author)

To test the hypothesis that social rearing may induce malleability, socially reared and socially isolated mallard duck, Anas platyrhynchos, embryos and hatchlings were exposed to the maternal call of a chicken, Gallus gallus domesticus, until 48 h after hatching. The hatchlings were then tested with the chicken call versus the mallard maternal…

Replies to comments by David Rush concerning the effectiveness of a WIC program in improving pregnancy outcomes among Massachusetts women. (GC)

Preliminary research findings showed that infants who received systematic prenatal musical stimulation exhibit remarkable attention behaviors, imitate accurately sounds made by adults, and appear to structure vocalization much earlier than infants who did not have prenatal musical stimulation. This evidence could radically modify concepts of music…

Argues that employers should be able to exclude fertile women from jobs that expose them to a teratogen or to a mutagen with significantly greater risks for female workers. (IRT)

School adjustment and achievement are at the heart of a child's development. Both are influenced by a myriad of factors that are complex and interconnected. For children with difficulties, school psychologists are integral to the assessment of those diverse factors and to the implementation of intervention strategies that help those children…

Comments on an article by Kotelchuck and colleagues concerning the benefits of WIC participation on pregnancy outcomes. Raises methodological considerations, especially the effects of duration of WIC participation and benefits, and the problem of matching study subjects with controls. (GC)

Presents information on prenatal brain development, detailing the functions controlled by the medulla, pons, and midbrain, and the implications for cognitive development. Concludes that fetal cognitive motor activity, including auditory discrimination, orienting, the wake-sleep cycle, fetal heart rate accelerations, and defensive reactions,…

Criticizes Lester, Als, and Brazelton's 1982 reanalysis of data presented by Scanlon, Nelson, Grylack, and Smith in 1979. Discusses (1) clinical interpretation of the ponderal index (a weight-for-length ratio); and (2) inaccurate measurement of crown-heel length; (3) Lester et al.'s suggested relationship between the ponderal index, maternal drug,…

Replies to Scanlon's criticism of Lester, Als, and Brazelton's 1982 reanalysis of Scanlon, Nelson, Grylack, and Smith's 1979 data. Discusses the accuracy and interpretation of the ponderal index, reiterating that Lester et al. suggested a hypothesis, not a proof, that low birth weight, combined with maternal obstetric drugs, negatively affects…