“…To experimentally manipulate arousal, we adapteda liquid reward-delivery paradigm commonly used in incentivized learning tasks (Imai, Kim, Sasaki, & Watanabe, 2014;Kim, Ling & Watanabe, 2015;O'Doherty et al, 2002;O'Doherty et al, 2004;O'Doherty, Dayan, Friston, Critchley, & Dolan, 2003;Seitz, Kim, & Watanabe, 2009). Such rewards have previously been shown to have both incentivizing and arousing properties (Bijleveld, Custers, & Aarts, 2009;Bray, Rangel, Shimojo, Balleine, & O'Doherty, 2008;Das, 2015).…”