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Vol. 36, No. 3, 2011
Issue release date: June 2011
Section title: Original Paper
Free Access
Neuroepidemiology 2011;36:162–168
(DOI:10.1159/000325779)

Socioeconomic Position and Cognitive Function in the Seychelles: A Life Course Analysis

Kobrosly R.W.a · van Wijngaarden E.a · Galea S.e · Cory-Slechta D.A.b · Love T.c · Hong C.f · Shamlaye C.F.g · Davidson P.W.d
Departments of aCommunity and Preventive Medicine, bEnvironmental Medicine, cBiostatistics and Computational Biology, and dPediatrics, University of Rochester School of Medicine and Dentistry, Rochester, N.Y., eDepartment of Epidemiology, Mailman School of Public Health, Columbia University, New York City, N.Y., and fCollege of Arts, Sciences, Engineering, University of Rochester, Rochester, N.Y., USA; gMinistry of Health, Victoria, Republic of Seychelles
email Corresponding Author

Abstract

Objective: Poorer socioeconomic conditions early in life have been linked with memory, attention and learning deficits in adulthood, as well as with specific areas of educational achievement. It remains unclear, however, whether these distal associations are mediated by more current socioeconomic factors. In this study, we sought to confirm the relation between early-life socioeconomic position (SEP) and adult cognitive function, and to examine potential mediation by contemporaneous SEP. Methods: Data from 463 young adults from the Main Cohort of the Seychelles Child Development Study were analyzed using subtests of the Cambridge Neurological Test Automated Battery and the Woodcock Johnson Test of Scholastic Achievement in relation to maternal Hollingshead Social Status Index scores at study enrollment (infancy), follow-up at 107 months, and follow-up at 17 years. Results: Findings include evidence of a link between infant-period SEP and 17-year memory, which was not mediated by childhood and 17-year SEP. Verbal and mathematical achievement at 17 years was associated with SEP at all points in the life course. Conclusions: SEP at different points during the young-adult life course may affect different cognitive domains later in life, which may provide targets for societal investment in ensuring adequate family resources throughout childhood and adolescence.

© 2011 S. Karger AG, Basel


  

Key Words

  • Socioeconomic factors
  • Cognitive function
  • Longitudinal studies

References

  1. Hackman DA, Farah MJ: Socioeconomic status and the developing brain. Trends Cogn Sci 2009;13:65–73.
  2. Turkheimer E, Haley A, Waldron M, D’Onofrio B, Gottesman II: Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 2003;14:623–628.
  3. Tong S, Baghurst P, Vimpani G, McMichael A: Socioeconomic position, maternal IQ, home environment, and cognitive development. J Pediatr 2007;151:284–288, 8 e1.
  4. Kiernan KE, Huerta MC: Economic deprivation, maternal depression, parenting and children’s cognitive and emotional development in early childhood. Br J Sociol 2008;59:783–806.
  5. Hillemeier MM, Farkas G, Morgan PL, Martin MA, Maczuga SA: Disparities in the prevalence of cognitive delay: how early do they appear? Paediatr Perinat Epidemiol 2009;23:186–198.
  6. Farah MJ, Shera DM, Savage JH, Betancourt L, Giannetta JM, Brodsky NL, Malmud EK, Hurt H: Childhood poverty: specific associations with neurocognitive development. Brain Res 2006;1110:166–174.
  7. Kaplan GA, Turrell G, Lynch JW, Everson SA, Helkala EL, Salonen JT: Childhood socioeconomic position and cognitive function in adulthood. Int J Epidemiol 2001;30:256–263.
  8. Turrell G, Lynch JW, Kaplan GA, Everson SA, Helkala EL, Kauhanen J, Salonen JT: Socioeconomic position across the lifecourse and cognitive function in late middle age. J Gerontol B Psychol Sci Soc Sci 2002;57:S43–S51.
  9. Richards M, Wadsworth ME: Long term effects of early adversity on cognitive function. Arch Dis Child 2004;89:922–927.
  10. Singh-Manoux A, Richards M, Marmot M: Socioeconomic position across the lifecourse: how does it relate to cognitive function in mid-life? Ann Epidemiol 2005;15:572–578.
  11. Kuh D, Ben-Shlomo Y: A life course approach to chronic disease epidemiology. Oxford, Oxford University Press, 1997.
  12. Marsh DO, Clarkson TW, Myers GJ, Davidson PW, Cox C, Cernichiari E, Tanner MA, Lednar W, Shamlaye C, Choisy O, et al: The Seychelles study of fetal methylmercury exposure and child development: introduction. Neurotoxicology 1995;16:583–596.
  13. Davidson PW, Myers GJ, Cox C, Wilding GE, Shamlaye CF, Huang LS, Cernichiari E, Sloane-Reeves J, Palumbo D, Clarkson TW: Methylmercury and neurodevelopment: longitudinal analysis of the Seychelles child development cohort. Neurotoxicol Teratol 2006;28:529–535.
  14. Davidson PW: The Child Development Studies in Seychelles: Principles of studying low-level neurotoxic exposures in children: using the Seychelles Child Development Study of methyl mercury as a prototype. Seychelles Med Dental J 2004;7:84–99.
  15. Hollingshead AB: Four factor index of social status. New Haven, Department of Sociology, Yale University, 1975.
  16. Davidson PW, Myers GJ, Cox C, Axtell C, Shamlaye C, Sloane-Reeves J, Cernichiari E, Needham L, Choi A, Wang Y, Berlin M, Clarkson TW: Effects of prenatal and postnatal methylmercury exposure from fish consumption on neurodevelopment: outcomes at 66 months of age in the Seychelles Child Development Study. JAMA 1998;280:701–707.
  17. Luciana M: Practitioner review: computerized assessment of neuropsychological function in children: clinical and research applications of the Cambridge Neuropsychological Testing Automated Battery (CANTAB). J Child Psychol Psychiatry 2003;44:649–663.
  18. Woodcock RW, McGrew KS, Mather N: Woodcock-Johnson III Tests of Achievement, Itasca, 2001.
  19. Read S, Pedersen NL, Gatz M, Berg S, Vuoksimaa E, Malmberg B, Johansson B, McClearn GE: Sex differences after all those years? Heritability of cognitive abilities in old age. J Gerontol B Psychol Sci Soc Sci 2006;61:P137–P143.
  20. Froehlich TE, Lanphear BP, Dietrich KN, Cory-Slechta DA, Wang N, Kahn RS: Interactive effects of a DRD4 polymorphism, lead, and sex on executive functions in children. Biol Psychiatry 2007;62:243–249.
  21. Sobel ME: Asymptotic confidence intervals for indirect effects in structural equation models; in Leinhardt S (ed): Sociological Methodology. Washington, American Sociological Association, 1982, pp 290–312.
  22. Ramey CT, Ramey SL: Prevention of intellectual disabilities: early interventions to improve cognitive development. Prev Med 1998;27:224–232.
  23. Hertzman C: The biological embedding of early experience and its effects on health in adulthood. Ann NY Acad Sci 1999;896:85–95.
  24. Hertzman C, Wiens M: Child development and long-term outcomes: a population health perspective and summary of successful interventions. Soc Sci Med 1996;43:1083–1095.
  25. Fulford AJ, Harbuz MS: An Introduction to the HPA axis. I. The Neurobiology of Stress; in Steckler T, Kalin NH, Reul JMHM (eds): Handbook on Stress and the Brain. Amsterdam, Elsevier, 2004.
  26. Aisa B, Tordera R, Lasheras B, Del Rio J, Ramirez MJ: Cognitive impairment associated to HPA axis hyperactivity after maternal separation in rats. Psychoneuroendocrinology 2007;32:256–266.
  27. Huot RL, Plotsky PM, Lenox RH, McNamara RK: Neonatal maternal separation reduces hippocampal mossy fiber density in adult Long Evans rats. Brain Res 2002;950:52–63.
  28. Guo G, Harris KM: The mechanisms mediating the effects of poverty on children’s intellectual development. Demography 2000;37:431–447.
  29. Power C, Jefferis BJ, Manor O, Hertzman C: The influence of birth weight and socioeconomic position on cognitive development: does the early home and learning environment modify their effects? J Pediatr 2006;148:54–61.
  30. Baron RM, Kenny DA: The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J Pers Soc Psychol 1986;51:1173–1182.
  31. VanderWeele TJ: Marginal structural models for the estimation of direct and indirect effects. Epidemiology 2009;20:18–26.

  

Author Contacts

Roni W. Kobrosly
Department of Community and Preventive Medicine
University of Rochester School of Medicine and Dentistry
601 Elmwood Avenue, Box 644, Rochester, NY 14642 (USA)
Tel. +1 585 276 4840, E-Mail Roni_Kobrosly@URMC.Rochester.edu

  

Article Information

Received: December 13, 2010
Accepted: February 16, 2011
Published online: April 20, 2011
Number of Print Pages : 7
Number of Figures : 0, Number of Tables : 3, Number of References : 31

  

Publication Details

Neuroepidemiology

Vol. 36, No. 3, Year 2011 (Cover Date: June 2011)

Journal Editor: Feigin V.L. (Auckland)
ISSN: 0251-5350 (Print), eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

Objective: Poorer socioeconomic conditions early in life have been linked with memory, attention and learning deficits in adulthood, as well as with specific areas of educational achievement. It remains unclear, however, whether these distal associations are mediated by more current socioeconomic factors. In this study, we sought to confirm the relation between early-life socioeconomic position (SEP) and adult cognitive function, and to examine potential mediation by contemporaneous SEP. Methods: Data from 463 young adults from the Main Cohort of the Seychelles Child Development Study were analyzed using subtests of the Cambridge Neurological Test Automated Battery and the Woodcock Johnson Test of Scholastic Achievement in relation to maternal Hollingshead Social Status Index scores at study enrollment (infancy), follow-up at 107 months, and follow-up at 17 years. Results: Findings include evidence of a link between infant-period SEP and 17-year memory, which was not mediated by childhood and 17-year SEP. Verbal and mathematical achievement at 17 years was associated with SEP at all points in the life course. Conclusions: SEP at different points during the young-adult life course may affect different cognitive domains later in life, which may provide targets for societal investment in ensuring adequate family resources throughout childhood and adolescence.

© 2011 S. Karger AG, Basel


  

Author Contacts

Roni W. Kobrosly
Department of Community and Preventive Medicine
University of Rochester School of Medicine and Dentistry
601 Elmwood Avenue, Box 644, Rochester, NY 14642 (USA)
Tel. +1 585 276 4840, E-Mail Roni_Kobrosly@URMC.Rochester.edu

  

Article Information

Received: December 13, 2010
Accepted: February 16, 2011
Published online: April 20, 2011
Number of Print Pages : 7
Number of Figures : 0, Number of Tables : 3, Number of References : 31

  

Publication Details

Neuroepidemiology

Vol. 36, No. 3, Year 2011 (Cover Date: June 2011)

Journal Editor: Feigin V.L. (Auckland)
ISSN: 0251-5350 (Print), eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Article / Publication Details

First-Page Preview
Abstract of Original Paper

Received: 12/13/2010
Accepted: 2/16/2011
Published online: 4/20/2011
Issue release date: June 2011

Number of Print Pages: 7
Number of Figures: 0
Number of Tables: 3

ISSN: 0251-5350 (Print)
eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Hackman DA, Farah MJ: Socioeconomic status and the developing brain. Trends Cogn Sci 2009;13:65–73.
  2. Turkheimer E, Haley A, Waldron M, D’Onofrio B, Gottesman II: Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 2003;14:623–628.
  3. Tong S, Baghurst P, Vimpani G, McMichael A: Socioeconomic position, maternal IQ, home environment, and cognitive development. J Pediatr 2007;151:284–288, 8 e1.
  4. Kiernan KE, Huerta MC: Economic deprivation, maternal depression, parenting and children’s cognitive and emotional development in early childhood. Br J Sociol 2008;59:783–806.
  5. Hillemeier MM, Farkas G, Morgan PL, Martin MA, Maczuga SA: Disparities in the prevalence of cognitive delay: how early do they appear? Paediatr Perinat Epidemiol 2009;23:186–198.
  6. Farah MJ, Shera DM, Savage JH, Betancourt L, Giannetta JM, Brodsky NL, Malmud EK, Hurt H: Childhood poverty: specific associations with neurocognitive development. Brain Res 2006;1110:166–174.
  7. Kaplan GA, Turrell G, Lynch JW, Everson SA, Helkala EL, Salonen JT: Childhood socioeconomic position and cognitive function in adulthood. Int J Epidemiol 2001;30:256–263.
  8. Turrell G, Lynch JW, Kaplan GA, Everson SA, Helkala EL, Kauhanen J, Salonen JT: Socioeconomic position across the lifecourse and cognitive function in late middle age. J Gerontol B Psychol Sci Soc Sci 2002;57:S43–S51.
  9. Richards M, Wadsworth ME: Long term effects of early adversity on cognitive function. Arch Dis Child 2004;89:922–927.
  10. Singh-Manoux A, Richards M, Marmot M: Socioeconomic position across the lifecourse: how does it relate to cognitive function in mid-life? Ann Epidemiol 2005;15:572–578.
  11. Kuh D, Ben-Shlomo Y: A life course approach to chronic disease epidemiology. Oxford, Oxford University Press, 1997.
  12. Marsh DO, Clarkson TW, Myers GJ, Davidson PW, Cox C, Cernichiari E, Tanner MA, Lednar W, Shamlaye C, Choisy O, et al: The Seychelles study of fetal methylmercury exposure and child development: introduction. Neurotoxicology 1995;16:583–596.
  13. Davidson PW, Myers GJ, Cox C, Wilding GE, Shamlaye CF, Huang LS, Cernichiari E, Sloane-Reeves J, Palumbo D, Clarkson TW: Methylmercury and neurodevelopment: longitudinal analysis of the Seychelles child development cohort. Neurotoxicol Teratol 2006;28:529–535.
  14. Davidson PW: The Child Development Studies in Seychelles: Principles of studying low-level neurotoxic exposures in children: using the Seychelles Child Development Study of methyl mercury as a prototype. Seychelles Med Dental J 2004;7:84–99.
  15. Hollingshead AB: Four factor index of social status. New Haven, Department of Sociology, Yale University, 1975.
  16. Davidson PW, Myers GJ, Cox C, Axtell C, Shamlaye C, Sloane-Reeves J, Cernichiari E, Needham L, Choi A, Wang Y, Berlin M, Clarkson TW: Effects of prenatal and postnatal methylmercury exposure from fish consumption on neurodevelopment: outcomes at 66 months of age in the Seychelles Child Development Study. JAMA 1998;280:701–707.
  17. Luciana M: Practitioner review: computerized assessment of neuropsychological function in children: clinical and research applications of the Cambridge Neuropsychological Testing Automated Battery (CANTAB). J Child Psychol Psychiatry 2003;44:649–663.
  18. Woodcock RW, McGrew KS, Mather N: Woodcock-Johnson III Tests of Achievement, Itasca, 2001.
  19. Read S, Pedersen NL, Gatz M, Berg S, Vuoksimaa E, Malmberg B, Johansson B, McClearn GE: Sex differences after all those years? Heritability of cognitive abilities in old age. J Gerontol B Psychol Sci Soc Sci 2006;61:P137–P143.
  20. Froehlich TE, Lanphear BP, Dietrich KN, Cory-Slechta DA, Wang N, Kahn RS: Interactive effects of a DRD4 polymorphism, lead, and sex on executive functions in children. Biol Psychiatry 2007;62:243–249.
  21. Sobel ME: Asymptotic confidence intervals for indirect effects in structural equation models; in Leinhardt S (ed): Sociological Methodology. Washington, American Sociological Association, 1982, pp 290–312.
  22. Ramey CT, Ramey SL: Prevention of intellectual disabilities: early interventions to improve cognitive development. Prev Med 1998;27:224–232.
  23. Hertzman C: The biological embedding of early experience and its effects on health in adulthood. Ann NY Acad Sci 1999;896:85–95.
  24. Hertzman C, Wiens M: Child development and long-term outcomes: a population health perspective and summary of successful interventions. Soc Sci Med 1996;43:1083–1095.
  25. Fulford AJ, Harbuz MS: An Introduction to the HPA axis. I. The Neurobiology of Stress; in Steckler T, Kalin NH, Reul JMHM (eds): Handbook on Stress and the Brain. Amsterdam, Elsevier, 2004.
  26. Aisa B, Tordera R, Lasheras B, Del Rio J, Ramirez MJ: Cognitive impairment associated to HPA axis hyperactivity after maternal separation in rats. Psychoneuroendocrinology 2007;32:256–266.
  27. Huot RL, Plotsky PM, Lenox RH, McNamara RK: Neonatal maternal separation reduces hippocampal mossy fiber density in adult Long Evans rats. Brain Res 2002;950:52–63.
  28. Guo G, Harris KM: The mechanisms mediating the effects of poverty on children’s intellectual development. Demography 2000;37:431–447.
  29. Power C, Jefferis BJ, Manor O, Hertzman C: The influence of birth weight and socioeconomic position on cognitive development: does the early home and learning environment modify their effects? J Pediatr 2006;148:54–61.
  30. Baron RM, Kenny DA: The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J Pers Soc Psychol 1986;51:1173–1182.
  31. VanderWeele TJ: Marginal structural models for the estimation of direct and indirect effects. Epidemiology 2009;20:18–26.