“…, inadequate stimulation (Bangirana et al, 2009;Walker et al, 2007), poor socioeconomic status (Boyede, Lesi, Ezeaka, & Umeh, 2013;Coscia et al, 2001), head injury (Salmond & Sahakian, 2005), toxins exposure (Koger, Schettler, & Weiss, 2005), and infectious diseases such as HIV (Baillieu & Potterton, 2008;Sherr, Mueller, & Varrall, 2009). Although HIV and environmental factors are largely preventable, they have been reported to decrease cognitive function independently in children (Boyede et al, 2013;Smith et al, 2006).…”