Childhood Poverty and Brain Development: The Role of Chronic Stress and Parenting

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DESCRIPTION (provided by applicant): One fifth of America's children grow up in poverty. While there is good evidence that this is harmful to health, achievement, and socio-emotional adjustment, very little is known about the brain basis that mediates the detrimental effects of poverty. We address two related primary questions with this research project: (1) How does childhood poverty influence adult brain structure and function? (2). What underlying mechanisms might account for childhood poverty - brain relationships? We hypothesize chronic physiological stress dysregulation as well as harsh, unresponsive parenting during childhood will account for some of the expected linkages between childhood poverty - adult brain structure and function - particularly in the hippocampus, amygdala, and the anterior cingulate/medial prefrontal cortex. This work will piggyback onto a 14 year, ongoing longitudinal research program of low and middle-income individuals focused on childhood poverty, physiological stress, and socio-emotional development conducted by Evans, a developmental psychologist at Cornell. Half of this sample (now age 22) grew up below the poverty line and half middle income. The sample is well characterized over their life course in terms of SES and other demographic variables, as well as both physical and psychosocial risk exposures. Primary outcome variables for this longitudinal cohort include multiple methodological indicators of physiological stress (neuroendocrine, cardiovascular, and metabolic) along with parental, self, and teacher ratings of socioemotional development (internalization, externalization, self regulation. In depth data on parenting are also included. The neuroimaging work will be conducted in the Department of Psychiatry, University of Michigan by Liberzon, with expertise in the neuroimaging of stress in health and mental illness, and by Swain a child psychiatrist studying the brain basis of parenting. Brain scanning will be divided into 3 sessions: the first will acquire high resolution images for volumetric and cortical thickness analyses. In addition, a selective emotional attention task as well as an emotion appraisal/re- appraisal task will probe the functionality of amygdala-prefrontal circuits. With scan two, parenting stimuli consisting of baby cries and pictures will be used to activate circuits believed to relate to parenting behavior and social interactions. Furthermore, working memory, delayed discounting and behavioral inhibition tasks will test cortical inhibition, decision-making, in cortico-cortical and cortico-hippocampal circuitry. Finally, immediately prior to the third fMRI scan, a Trier Social Stress Test that reliably generates elevated cortisol levels in laboratory environment will be performed. The subsequent scans will directly assess brain function following acute stress induction, and allow comparison with the baseline brain function in these same subjects, including a repetition of the selective emotional attention task, the parenting task and the emotional face assessment task to re-examine amygdala, hippocampus and prefrontal cortex performance. These experiments utilize a uniquely well-characterized longitudinal sample of low- and middle-income individuals in combination with a comprehensive set of conceptually derived, innovative but also validated neuroimaging paradigms. The aim of this project is to examine the potential impacts of childhood poverty on the brain. We will examine areas of the brain well studied in relation to chronic stress and parent-child interactions.