“…This independence hypothesis has been supported by a behavioral study in which no correlation in performance was found between the three networks, measured using a behavioral testing procedure (Fan, McCandliss, Sommer, Raz, & Posner, 2002). However, in a larger study using a similar testing procedure, a significant correlation between the orienting and executive control network was found (Fossella, Posner, Fan, Swanson, & Pfaff, 2002). Interactions among other networks were also observed using a slightly modified task (Callejas, Lupianez, & Tudela, 2004).…”