Edward Lonky

Cognitive development in preschool children prenatally exposed to PCBs and MeHg.

A number of epidemiological studies have shown predictive relationships between prenatal exposure to polychlorinated biphenyls (PCBs) and subtle deficits in cognitive development in infancy through the preschool years [Child Dev. 56 (1985) 853; J. Pediatr. 116 (1990) 38; J. Pediatr. 134 (1999) 33; Toxicol. Lett. 102-103 (1998) 423; Neurotox. 21 (6) (2000) 1029-1038]. However, since not all studies have demonstrated these relationships (J. Pediatr. 119 (1991) 58-63), debate regarding the role of prenatal PCB exposure in cognitive development continues. The current study was designed to provide additional data to assist in resolving this question. Two hundred twelve children enrolled in the Oswego Newborn and Infant Development Project were assessed using the McCarthy Scales of Childrens Abilities at 38 months of age, followed by a reassessment at 54 months of age. The relationship between prenatal exposure to PCBs (cord blood PCBs) and McCarthy performance was assessed at both ages after first controlling for a wide range of important predictors of cognitive development, including socioeconomic status (SES), maternal IQ, maternal education, home environment, cigarette smoking, and many others. Cord blood PCBs were statistically significant predictors of small but measurable deficits in McCarthy performance at 38 months of age. Moreover, a significant interaction between cord blood PCBs and maternal hair mercury (MeHg) was found, such that negative associations between prenatal MeHg exposure and McCarthy performance were found in subjects with higher levels of prenatal PCB exposure. No relationship between PCBs and/or MeHg and McCarthy performance was observed when the children were reassessed almost 1.5 years later (54 months of age). Inspection of the age-related trajectory of McCarthy performance revealed that the more highly exposed children caught up with the least exposed children by 54 months. Although the current data partially replicate the findings of Jacobson et al., Patandin et al., and Walkowiak et al. [J. Pediatr. 116 (1990) 38; J. Pediatr. 134 (1999) 33; Lancet 358 (2001) 1602], results reported here suggest that functional recovery may occur. Moreover, the interaction between PCB and MeHg cannot be considered conclusive until it has been replicated in subsequent investigations.

Neonatal Behavioral Assessment Scale Performance in Humans Influenced by Maternal Consumption of Environmentally Contaminated Lake Ontario Fish

Behavioral effects in neonates of their mothers’ consumption of Lake Ontario fish were examined using the Neonatal Behavioral Assessment Scale (NBAS). Newborns of women who had consumed > 40 equivalent pounds of fish were placed in a high-exposure group (n = 152), those of women who had consumed < 40 equivalent pounds of fish were placed in a low-exposure group (n = 243), and offspring of women who reported having never eaten Lake Ontario fish comprised the control group (n = 164). Assessments were given at 12–24 hours after birth, and again at 25–48 hours after birth. Despite relatively low levels of fish consumption, newborns in the high-exposure group scored more poorly than those in both the low-exposure and control groups on the Reflex, Autonomic, and Habituation clusters of the NBAS. No significant group differences were found on the Orientation, Range of State, Regulation of State, or Motor clusters of the NBAS, nor did birth weight or head circumference differ between groups. These results represent the first replication and extension of the neonatal results of the Lake Michigan Maternal Infant Cohort study (Jacobson et al. 1984).

Prenatal PCB exposure and neonatal behavioral assessment scale (NBAS) performance

We examined the relationship between prenatal (cord blood) polychlorinated biphenyls (PCBs) and Neonatal Behavioral Assessment Scale (NBAS) performance in babies born to women who consumed contaminated Lake Ontario fish. Cord blood PCBs, DDE, HCB, Mirex, lead, and hair mercury levels were determined for 152 women who reported never consuming Lake Ontario fish and 141 women who reported consuming at least 40 PCB-equivalent lbs. of Lake Ontario fish over their lifetime. Earlier work demonstrated that the newborns of fish eaters are exposed to a more heavily chlorinated distribution of PCB congeners, and that highly chlorinated PCBs (hepta-, octa-, and nonachlorinated biphenyls) are most strongly correlated with breast milk levels, perhaps providing the best index of PCB exposure in the Oswego cohort. Given the above, one would predict that these PCBs would be related to impaired performance on those NBAS clusters associated with fish consumption: namely Habituation, Autonomic, and Reflex clusters of the NBAS. Excepting the Relex cluster, these predictions were confirmed. Results revealed significant linear relationships between the most heavily chlorinated PCBs and performance impairments on the Habituation and Autonomic clusters of the NBAS at 25-48 h after birth. Additionally, higher prenatal PCB exposure was associated with a nonspecific performance impairment on the NBAS as evidenced by a significantly greater proportion of NBAS scales in which poor performance was exhibited (more than 1 standard deviation below the mean) in the most highly exposed neonates. Moreover, PCBs of lighter chlorination were unrelated to NBAS performance, as were DDE, Mirex, HCB, lead, and mercury. These results corroborate our earlier findings linking Lake Ontario fish consumption to the most heavily chlorinated PCB congeners, and suggest that the chlorination and persistence of PCBs may be an important factor both for exposure assessment and for determining relationships with neurobehavioral functions.

The Relationship between Prenatal PCB Exposure and Intelligence (IQ) in 9-Year-Old Children

Background Several epidemiologic studies have demonstrated relationships between prenatal exposure to polychlorinated biphenyls (PCBs) and modest cognitive impairments in infancy and early childhood. However, few studies have followed cohorts of exposed children long enough to examine the possible impact of prenatal PCB exposure on psychometric intelligence in later childhood. Of the few studies that have done so, one in the Great Lakes region of the United States reported impaired IQ in children prenatally exposed to PCBs, whereas another found no association. Objectives This study was designed to determine whether environmental exposure to PCBs predicts lower IQ in school-age children in the Great Lakes region of the northeastern United States. Methods We measured prenatal exposure to PCBs and IQ at 9 years of age in 156 subjects from Oswego, New York. We also measured > 50 potential predictors of intelligence in children, including repeated measures of the home environment [Home Observation for Measurement of the Environment (HOME)], socioeconomic status (SES), parental IQ, alcohol/cigarette use, neonatal risk factors, and nutrition. Results For each 1-ng/g (wet weight) increase in PCBs in placental tissue, Full Scale IQ dropped by three points (p = 0.02), and Verbal IQ dropped by four points (p = 0.003). The median PCB level was 1.50 ng/g, with a lower quartile of 1.00 ng/g and an upper quartile of 2.06 ng/g. Moreover, this association was significant after controlling for many potential confounders, including prenatal exposure to methylmercury, dichlorodiphenyldichloroethylene, hexachlorobenzene, and lead. Conclusions These results, in combination with similar results obtained from a similar study in the Great Lakes conducted 10 years earlier, indicate that prenatal PCB exposure in the Great Lakes region is associated with lower IQ in children.

Response inhibition during Differential Reinforcement of Low Rates (DRL) schedules may be sensitive to low-level polychlorinated biphenyl, methylmercury, and lead exposure in children.

Background Animal studies have shown that exposure to common, low-level environmental contaminants [e.g., polychlorinated biphenyls (PCBs), lead] causes excessive and inappropriate responding on intermittent reinforcement schedules. The Differential Reinforcement of Low Rates task (DRL) has been shown to be especially sensitive to low-level PCB exposure in monkeys. Objectives We investigated the relationships between prenatal PCB and postnatal Pb exposure performance on a DRL schedule in children. We predicted that a) prenatal PCB exposure would reduce interresponse times (IRTs) and reinforcements earned, and b) postnatal Pb exposure would reduce IRTs and reinforcements earned. Methods We tested 167 children on a DRL20 (20 sec) reinforcement schedule, and recorded IRTs and the number of reinforced responses across the session. We measured prenatal PCB exposure (cord blood), methylmercury (MeHg) (maternal hair), and postnatal Pb exposure (venous blood), and > 50 potentially confounding variables. Results Results indicated impaired performance in children exposed to PCBs, MeHg, and Pb. Children prenatally exposed to PCBs responded excessively, with significantly lower IRTs and fewer reinforcers earned across the session. In addition, exposure to either MeHg or Pb predicted statistically significant impairments of a similar magnitude to those for PCBs, and the associated impairments of all three contaminants (PCB, MeHg, and Pb) were statistically independent of one another. Conclusions These results, taken with animal literature, argue the high sensitivity of DRL performance to low-level PCB, MeHg, and Pb exposure. Future research should employ behavioral tasks in children, such as DRL, that have been demonstrably sensitive to low-level PCB, MeHg, and Pb exposure in animals.

Young adults' scores on the defining issues test as a function of a “self” versus “other” presentation mode

One hundred college students were randomly divided into four groups and were administered the standard version (i.e., other-orientation) of the Defining Issues Test (DIT) and/or a Modified version (i.e., self-orientation) of the same instrument on two separate occasions. Subjects displayed greater amounts of principled moral reasoning when responding to the standard (other-orientation) rather than the modified (self-orientation) version of the DIT. Also, significant test-retest reliability was obtained for the standard, but not the modified, version of the DIT. The role of affective factors in the evaluation of moral problems involving the self versus hypothetical others was discussed.

Political Values and Moral Judgment in Adolescence

This study examines the developmental nature of the relationship between moral judgment and the structure of political values and beliefs. In addressing questions regarding the structure and development of political ideology in adolescents and young adults, we have attempted to combine the methods of a cognitive developmental approach to political development with those of political socialization and political science theorists. Recent investigations employing a cognitive developmental approach to political development have looked at structural differences in the extent of understanding and comprehension

Moral judgment and sex role orientation as a function of self and other presentation mode

Gilligans concern for a negative bias in assessing moral reasoning based on feminine interpersonal orientations and corresponding positive bias in favor of masculine orientations of justice and equity was explored. Bems Sex Role Inventory provided a psychological index of orientation rather than only biological sex. College men and women completed Rests moral dilemmas (DIT) in the usual manner-other condition-or assumed the role of the central character-self condition. The latter procedure augmented affective dimensions assumed to underlie orientation differences. Males in the other condition scored higher on the DIT than those in the self condition; females revealed the opposite pattern. Using the sex role categories, it appeared that androgynous males had higher DIT scores in the self condition than in the other condition, in direct contrast to the overall results for males. For females who were androgynous or masculine in orientation, the self condition resulted in higher DIT scores than the other condition. Generally, the greater affective demands in the self condition produced a higher frequency of Stage 3 use for men and women regardless of sex role orientation. The other condition showed a higher percentage of Stage 4 use among males and females independent of sex role orientation. Sex role orientation and affective arousal were discussed in terms of Gilligans view of moral judgment development.

LOGICAL CONCEPT PREREQUISITES TO POLITICAL DEVELOPMENT IN ADOLESCENCE

This research examined the nature of cognitive stages of political reasoning by adolescents and young adults. It is a further test of the cognitive model of political development. College sophomores received individually administered tasks of formal operations, a group-administered test of formal operations, and the Political Judgment Interview, a semi-structured interview of five dilemmas which focus on questions relating to the jus: distribution of political resources. Analysis supported a necessary but not sufficient relationship between logical concept and political reasoning. Taken with other research findings, the present results provide evidence for a domain of reasoning which is not totally encompassed by reasoning in either the logical or moral domain.