(e.g. more rhythmic and lateral tongue protrusions) than adults (Wilmouth & Spear, 2009). Such increases in positive taste reactivity and sucrose intake among adolescents are reminiscent of the greater motivation for natural, drug and alcohol rewards revealed in the CPP, second-order conditioning and tachycardia studies described earlier. The enhanced effects seen during adolescence using these presumptive measures of positive hedonic affect are also evocative of human imaging studies suggesting greater recruitment of NAc during receipt of rewards in adolescents than adults (e.g., Ernst et al., 2005; Galvan et al., 2006), although these findings are not ubiquitous (e.g., Bjork et al., 2004).
