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 sh...
| Publicado en: | Environmental Health Perspectives Vol. 114; no. 12; pp. 1923 - 1930 |
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| Autores principales: | , , , , , , , |
| Formato: | research Journal Article |
| Publicado: |
National Institute of Environmental Health Sciences
Dec2006
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=105952565&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 105952565 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00916765 3B5 jtl: Environmental Health Perspectives issn: 00916765 maglogo: N pubinfo: dt: Dec2006 vid: 114 iid: 12 pid: 56539 pub: National Institute of Environmental Health Sciences place: Research Triangle Park, North Carolina artinfo: ui: 105952565 105952565 2009367772 10.1289/ehp.9216 NLM17185286 105952565 ppf: 1923 ppct: 7 formats: fmt: @attributes: type: P tig: atl: Response inhibition during differential reinforcement of low rates (DRL) schedules may be sensitive to low-level polychlorinated biphenyl, methylmercury, and lead exposure in children. aug: au: Stewart PW Sargent DM Reihman J Gump BB Lonky E Darvill T Hicks H Pagano J sug: subj: Environmental Pollutants Poisoning Lead Organic Chemicals Poisoning Polychlorinated Biphenyls Poisoning Prenatal Exposure Delayed Effects Analysis of Variance Child Child, Preschool Dose-Response Relationship, Drug Female Infant Infant, Newborn Learning Drug Effects Linear Regression Male Pregnancy Prenatal Exposure Delayed Effects Psychosocial Factors Reinforcement (Psychology) Human Child: 6-12 years Child, Preschool: 2-5 years Infant: 1-23 months Infant, Newborn: birth-1 month Female Male ab: 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. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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