Towards a Cognitive Science of Social Inequality: Children's attention-related ERPs and cortisol vary with their socioeconomic status

Towards a Cognitive Science of Social Inequality: Children’s Attention-related ERPs and Salivary Cortisol vary with their Socioeconomic Status Amedeo D’Angiulli ( amedeo@connect.carleton.ca ), Carleton University , Institute of Interdisciplinary Studies & Department of Psychology, 1125 Colonel By Drive Ottawa, ON K1S 5B6 Canada Joanne Weinberg ( joannew@interchange.ubc.ca ), The University of British Columbia, Department of Cellular and Physiological Sciences, 2350 Health Sciences Mall Vancouver, BC V6T 1Z3 Canada Ruth Grunau ( rgrunau@cw.bc.ca ), The University of British Columbia, Department of Pediatrics, 4480 Oak St. Vancouver, BC V6H 3V4 Canada Clyde Hertzman ( clyde.hertzman@ubc.ca ) The University of British Columbia , Department of Health Care & Epidemiology, 5804 Fairview Avenue Vancouver, BC V6T 1Z3 Canada Pavel Grebenkov ( pgrebenk@connect.carleton.ca ), Carleton University , Institute of Cognitive Science, 1125 Colonel By Drive Ottawa, ON K1S 5B6 Canada SES children generally live in environments that are more crowded, chaotic, noisy and dangerous (e.g., Evans, 2004) than high-SES children and thereby they experience more stressful, unpredictable life events and less sense of control (McLoyd, 1998). Research attempting to clarify how SES may exert its influence on health and well-being shows that stress and SES are associated (Baum, Garofalo & Yali, 1999). Form example, compared to high-SES individuals, low-SES individuals are more likely to be exposed to environmental challenges that elicit hyper-vigilance (Kristenson et al., 2004). If low- and high-SES children live in environments with different characteristics, this may be regarded as a particular instance in which children develop different ways of integrating cognitive and emotional aspects involved in adaptation and self-regulation (Blair, 2002). Accordingly, it is reasonable to expect children from different SES backgrounds to develop experience-dependent patterns of neural activity and self-regulation that are differentially associated with attention and executive cognitive processes depending on the types of environmental challenges they normally encounter. Although the relationship between SES and development may influence some of the most important, and evolutionarily recent functions associated with frontal brain activity such as selective attention and executive control (Farah, Noble, & Hurt, 2004), there has been little direct study of the brain processes that mediate the effects of childhood experiences associated with living conditions, as reflected by proxy SES indicators, on executive performance. Like other cognitive abilities required at school, at home, or in the community, children’s selective attention may be expected to be subject to the potent influences of Abstract We investigated the relationships between socioeconomic status (SES) and the neural correlates of selective attention by comparing event-related potentials (ERPs) in low- and high-SES preadolescents during an auditory selective attention task. Salivary cortisol levels were also determined before and after the task. ERP difference waveforms between attended and unattended auditory stimuli (Nd, difference negativity) were significant in the high-SES group but not in the low-SES group. However, post-ERP cortisol levels were elevated only for low-SES children and there were no differences between the groups in reaction times and accuracy. We conclude that low-SES children have reduced attentional selectivity, but at the cost of heightened executive control which allows them to inhibit responding to attended distracters and perform the task as well as high-SES children. Socioeconomic status reflects living conditions associated with differences or “inequalities” in a series of outcomes during different periods of the life-course (e.g., Graham & Power, 2004). In the last 30 years, research has established that family income and other indicators of socioeconomic status of origin (SES), such as parental occupation or education, are highly associated with cognitive and achievement outcomes in childhood (review in Bradley & Corwyn, 2002). Several environmental variables, including physical health, home environment, early education and neighbourhood characteristics, co-vary systematically with SES and are likely to influence the SES gap in children’s cognitive performance and achievement. In particular, low-