title: Response inhibition at 8 and 9 1/2 years of age in children prenatally exposed to PCBs.
abstract: We previously reported a relationship between prenatal PCB exposure and impulsive (excessive) responding on a continuous performance task in children at 4 1/2 years of age [P.W. Stewart, S. Fitzgerald, J. Reihman, B. Gump, E. Lonky, T. Darvill, J. Pagano, P. Hauser, Prenatal PCB exposure, the corpus callosum, and response inhibition, Environmental Health Perspectives 111 (13) (2003b) 1670-1677.]. The current study investigated the stability of this effect at 8 and 9 1/2 years of age. We tested the hypothesis that PCB-related impulsive responding might be a function of impaired response inhibition. Children (n=202) enrolled in the Oswego Children's Study were tested at 8 years of age using the NES2 Continuous Performance Test (CPT). This was followed by a series of Extended Continuous Performance Tests (E-CPT) at 9 1/2 years of age, designed to dissociate response inhibition from sustained attention. After taking into account more than 50 measured covariables, including maternal IQ, maternal sustained attention and maternal response inhibition, results revealed PCB-related associations with impulsive responding at both testing ages. At 8 years of age, prenatal PCB exposure was associated with increased impulsive responding on the CPT. At 9 1/2 years of age, E-CPT testing clearly indicated that the PCB-related impulsive responding was due to impaired response inhibition and not impaired sustained attention. These results were significant after extensive and rigorous control for multiple potential confounders, including several non-PCB contaminants (prenatal MeHg, DDE, HCB, and pre- and postnatal Pb). These data are consistent with, and in fact predicted by, several studies in PCB-exposed animals.
authors.affiliation: 304 Mahar Hall, State University of New York at Oswego, Oswego, NY 13126, USA. pstewart1@oswego.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Stewart
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Reihman
authors.forename: Brooks
authors.initials: B
authors.lastname: Gump
authors.forename: Edward
authors.initials: E
authors.lastname: Lonky
authors.forename: Thomas
authors.initials: T
authors.lastname: Darvill
authors.forename: James
authors.initials: J
authors.lastname: Pagano
mesh_terms: D002648:Child; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D011078:Polychlorinated Biphenyls / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000523:psychology*; D011931:Reactive Inhibition; D013647:Task Performance and Analysis
chemical_list: D011078:Polychlorinated Biphenyls