Taken together studies of both neuroanatomy and neural

Taken together, studies of both neuroanatomy and neural functional activation yield SES-related differences in gnrh antagonist regions that support language; these findings, however, have not reliably been linked to differences in language functioning. Importantly, a recent study has shown no measurable differences in electrophysiological brain activity between lower- and higher-SES newborn babies, although EEG power at birth was associated with infants’ language and memory outcomes 15 months later (Brito et al., 2016), Similarly, another study showed no early differences in temporal gray matter, but different frontal and parietal growth trajectories over the first months of life (Hanson et al., 2013). These findings provide preliminary support for the formulation that, over early sensitive periods, children’s environments systematically influence functional brain development. Yet the majority of studies in the area of the cognitive neuroscience of SES rely on SES as a crude proxy for both children’s environment and their language skill. SES-related brain differences are presumed to be indicative of language deficits in lower-SES children, regardless of whether a relation between SES and language skill was confirmed in a given study. Taken together, evidence for brain-based differences in language skill between higher- and lower-SES children remains negligible.
Toward a nuanced understanding: conclusions and future directions New technology is allowing researchers to examine more systematically variations in the home language environment that are hypothesized to be related to language outcomes. For example, the LENA digital language processor (DLP) is a digital recorder worn in children’s front pockets that can unobtrusively sample children’s home language environments by recording proximal speech for up to 16h (Xu et al., 2008). Using LENA analysis software to measure child-directed speech (CDS) may reduce bias introduced in researcher-prescribed settings and allow for a more accurate estimate of the speech children hear regularly. In fact, measures of naturally-occurring CDS derived using LENA have been shown to be related to children’s early trajectories of language development (Weisleder and Fernald, 2013). Importantly, these investigators recruited children who came from similar neighborhoods, shared a common ethnicity, were exposed to the same first language in the home, and had minimal exposure to any second language. The cognitive neuroscience of SES would benefit from recruiting children in a similar manner. Investigators should capitalize on these advancements within the field of language development to examine whether specific elements of CDS, including measures of both language quantity and quality, are related to brain structure and function, and test whether these neural differences mediate the association between CDS and language skill. Although reverse inference is difficult to avoid − and indeed, has been useful − in studies of the brain (Poldrack, 2011), it is important to be cautious in interpreting results of studies concerning SES. Not only is SES a broad and poorly defined variable (Braveman et al., 2005), but it is linked to many other factors that may confound the interpretability of potential results. Moreover, SES is highly politicized; the popular press picks up on studies of SES and the brain with alarming alacrity and distortion. Already, the New Yorker has published an article declaring that poverty results in a “weakened” brain due to the deprivation of the environment, stating, in fact, that “the scientific consensus has become clear” (Ostrander, 2015, p. 3). This is the case even when research findings are discussed with appropriate caution, and highlights the need for researchers to seek training in interacting effectively with the press.
Funding Preparation of this article was facilitated by NIMH grant R01-MH101495 to IHG.