HSSs strongly activated brain regions involved in reinforcement (posterior medial OFC) and arousal (right anterior insula). In response to high-arousal stimuli, HSSs activated the posterior medial OFC more strongly than did LSSs, but the Arousal × Sensation Seeking interaction was only marginally significant. This region is often associated with the presentation of primary reinforcers, such as taste and pain, regardless of their reward value (Kringelbach & Rolls, 2004). The right anterior insula was also more strongly activated in HSSs than in LSSs for high-arousal stimuli. Strong neurobiological and neuroanatomical evidence supports the view that the right anterior insula may be a somatic marker for arousal and sympathetic stress responses (Craig, 2005; Critchley, Melmed, Featherstone, Mathias, & Dolan, 2002; Paulus et al., 2003; Zuckerman, 2005). In addition, the insula responds to pictures of appetizing food (Simmons, Martin, & Barsalou, 2005), is activated during sexual arousal (Stoleru et al., 1999), and may be involved in addictive cravings and urges (Naqvi, Rudrauf, Damasio, & Bechara, 2007); these findings suggest an association with appetitive behavior. In the present study, peak activation in the right
