Both the pervasiveness of EF deficits in childhood disorders and the salience of EF for studies of normal brain development can be understood in terms of the protracted nature of EF development. EF skills begin to emerge in infancy (Diamond, 1988), show marked improvements across toddlerhood and the preschool period (Carlson et al., 2004; Hughes & Ensor, 2007; Hughes et al., 2010) and continue to improve across the school years (e.g. Huizinga et al., 2006), with some aspects of EF continuing to develop throughout adolescence (Luciana, Conklin, Cooper, & Yarger, 2005; Luna, Garver, Urban, Lazar, & Sweeney, 2004)