The effect of early deprivation on executive attention in middle childhood.

Regulatory abilities may be particularly sensitive to deprivation in early caregiving environments. Sensitive and responsive caregivers scaffold infant attention regulation and arousal (e.g., Carlson, Jacobvitz, & Sroufe, 1995). Infants lacking supportive and consistent caregivers, such as children reared in institutions (e.g., orphanages), are at increased risk of attention and behavior regulatory problems (e.g., Goldfarb, 1943; Kreppner, O’Connor, & Rutter, 2001; Tizard & Hodges, 1978), risk that increases with the length of time in institutional care (e.g., Gunnar & van Dulmen, 2007; Kumsta et al., 2010; Wiik et al., 2011). To date, there is only emerging evidence regarding the specific nature of attention and regulatory problems in institutionalized and post-institutionalized children. For example, in two studies, as a group post institutionalized (PI) children performed more poorly than children adopted early from foster care and non-adopted children on tasks assessing visual attention and inhibition of immediate impulses (Bruce, Tarullo & Gunnar, 2009; Pollak et al., 2010). Additionally, toddlers adopted from Russian institutionswere more likely to score lower on parent-report measures of executive functioning than were children adopted earlier (Merz & McCall, 2010). These results suggest that attentional difficulties noted across reports of post-institutionalized children (e.g., Ames, 1997; Maclean, 2003) may be related to difficulties with inhibitory control and selective attention. However, very little is known about the neurobiology specifically associated with these attention difficulties. Five published imaging studies implicate structural differences between PI and never-institutionalized children (Bauer, Hanson, Pierson, Davidson, & Pollak, 2009; Chugani et al., 2001; Eluvathingal et al., 2006; Mehta et al., 2009; Tottenham et al., 2010). However, because these studies did not include an adoption comparison group, such as children adopted from settings other than institutional care, the observed differences could have been due to factors beyond institutional care associated with being given up for adoption. A recent event-related potential study of attention did have an appropriate comparison group, examining institutionalized children placed in foster care versus those who remained in institutional “care as usual”. Although only the “care as usual” group showed behavioral deficits on the Go/No-go task, both groups showed smaller P300 amplitudes than the never-institutionalized children reared in their birth families (McDermott, Westerlund, Zeanah, Nelson, & Fox, 2012). The goal of this study was to help fill in our understanding of the neurobiological correlates of attention problems that follow early institutional deprivation by focusing on executive attention, a multi-faceted construct involving inhibitory control, response monitoring, and conflict resolution (Rueda, Posner, & Rothbart, 2005). Specifically, we examined behavioral performance and event-related potentials (ERPs) during Go/No-go and Flanker tasks. ERPs represent summated electrical activity of the brain conducting to the scalp surface, where it is recorded by small sensors. Unlike fMRI, ERPs have excellent temporal resolution (Nelson & McCleery, 2008). Go/No-go assesses inhibitory control and is associated with activation of the ventrolateral prefrontal cortex and anterior cingulate cortex (e.g., Durston et al., 2002; Schulz et al., 2004). Flanker, a measure of selective attention and conflict monitoring, is associated with activation of the dorsolateral prefrontal cortex and anterior cingulate cortex (e.g., Botvinick, Nystrom, Fissell, Carter, & Cohen, 1999; Casey et al., 2000). Our ERP analyses focused on five components: P2, N2, P300, error-related negativity (ERN), and Pe. P2 reflects a sensory-driven response to visual stimuli and the matching of visual perception to cognitive expectation (Fabiani, Gratton, & Coles, 2000). N2 is associated with cognitive control, including inhibitory control, stimulus discrimination and categorization (Nieuwenhuis, Yeung, Wildenberg, & Ridderinkhof, 2003). P300 reflects responses to a rare target among frequent non-targets and cognitive processes including inhibitory control and stimulus evaluation (Tekok-Kilic, Shucard, & Shucard, 2001). ERN reflects initial response monitoring immediately following an incorrect response (van Veen & Carter, 2002). Lastly, Pe represents further error processing and awareness (Overbeek, Nieuwenhuis, & Ridderinkhof, 2005). We hypothesized that internationally adopted PI children would be more likely to demonstrate poorer inhibitory control and conflict monitoring than peers without extensive histories of institutionalization. Two comparison groups were included: non-adopted children raised in similarly-resourced families as those who adopt internationally (Loman, Wiik, Frenn, Pollak, & Gunnar, 2009) and children internationally adopted at earlier ages primarily from foster care to account for factors associated with international adoption (e.g., poverty, poor prenatal care; Johnson, 2000). Although this is the first study to explore ERPs associated with two types of attentional control tasks within the same sample of post-institutionalized children, previous ERP research (e.g., face processing, Moulson, Westerlund, Fox, Zeanah, & Nelson, 2009; inhibitory control, McDermott et al., 2012) suggests that post-institutionalized children may have smaller amplitudes and slower latencies for ERP waveforms.