Trends in Cognitive Sciences
ReviewSocioeconomic status and the developing brain
Section snippets
Why study the neuroscience of socioeconomic status?
What is socioeconomic status (SES), and why would a cognitive neuroscientist have anything to say about it? Volumes have been written about the first question, but for present purposes we will simply say that virtually all societies have better off and less well off citizens, and that differences in material wealth tend to be accompanied by noneconomic characteristics such as social prestige and education 1, 2, 3, 4, 5, 6 (Box 1). SES refers to this compound of material wealth and noneconomic
Neurocognitive performance
Although IQ tests reflect the function of the brain, they are relatively uninformative concerning the specific neurocognitive systems responsible for performance differences. Recent research has, therefore, incorporated behavioral tests that support more specific inferences. For purposes of relating task performance to underlying systems, we propose the following simple parse of brain function into five relatively independent neurocognitive systems defined anatomically based on studies of
Electrophysiological measures
To investigate SES disparities in brain development more directly, several research groups have recently turned to electrophysiological measures of neurocognitive processing. Baseline electroencephalographic (EEG) activity has been used to assess overall differences in resting brain function, and two studies have found differences in the pattern of EEG as a function of SES. In a study of Mexican preschool children, Otero and colleagues [38] found evidence consistent with a maturational lag in
Neuroimaging
For purposes of localizing differences in cognitive ability to specific, anatomically defined neural systems, magnetic resonance imaging (MRI) provides far more direct and accurate information than the most carefully chosen behavioral tasks or the densest array of scalp electrodes. Unfortunately, there are few studies of SES using functional or structural neuroimaging. Two studies have so far examined SES disparities in cognitive function with functional MRI (fMRI) in normal children and one
Manipulations of social status
The vast majority of cognitive neuroscience laboratories conduct research with participants of middle SES. The restricted range of SES in easily accessible subject populations is undoubtedly partly responsible for the neglect of SES as a variable in human brain development and function. Some researchers who are interested in the effects of social hierarchy on neurocognitive function have found a way to address the issue with middle SES subjects: they have manipulated subjects’ social status and
Mechanisms
What is the cause of SES differences in brain function? Is it contextual priming? Is it social causation, reflecting the influence of SES on brain development? Alternatively, is it social selection, in which abilities inherited from parents lead to lower SES [9]? Current research on SES and brain development is not designed to answer this question. However, research on SES and IQ is relevant and supports a substantial role of SES and its correlated experience as causal factors 1, 7, 8, 9, 10, 11
Current knowledge and future research directions
Although abundant research has documented the influence of SES on cognitive ability as measured by IQ tests and school achievement, we have only the most preliminary understanding of the specific neurocognitive effects of SES. Research to date indicates that SES disparities are most robust in language and executive functions, and perhaps also declarative memory, although they are not restricted to these functions, and much remains to be learned about the specific aspects of these functions
Acknowledgements
The writing of this article was supported by NIH grants R01-HD043078, R01-HD055689, R01-DA14129 and R01 DA0189913, as well as ONR grant N000140710034. The authors thank Kim Noble for her tremendous contributions to much of the research reviewed here and David Kraemer for assistance with figure preparation.
References (80)
Childhood poverty: specific associations with neurocognitive development
Brain Res.
(2006)- et al.
Self-regulation and the income-achievement gap
Early Child. Res. Q.
(2008) Socioeconomic position across the lifecourse: how does it relate to cognitive function in mid-life?
Ann. Epidemiol.
(2005)Development of attentional networks in childhood
Neuropsychologia
(2004)Poverty, cultural disadvantage and brain development: a study of pre-school children in Mexico
Electroencephalogr. Clin. Neurophysiol.
(1997)Resting frontal brain activity: linkages to maternal depression and socio-economic status among adolescents
Biol. Psychol.
(2004)Use it or lose it? SES mitigates age-related decline in a recency/recognition task
Neurobiol. Aging
(2008)Socioeconomic status predicts hemispheric specialisation of the left inferior frontal gyrus in young children
Neuroimage
(2008)Power affects basic cognition: increased attentional inhibition and flexibility
J. Exp. Soc. Psychol.
(2007)Know your place: neural processing of social hierarchy in humans
Neuron
(2008)