Another area of executive function that is compromised by prenatal alcohol exposure is fluency. Children exposed to alcohol during gestation demonstrate deficits on both traditional and set-shifting measures of verbal and nonverbal fluency. In one study, deficits on higher-order switching tasks were not accounted for by traditional fluency tasks, and deficits persisted when IQ was controlled statistically (Schonfeld, Mattson, Lang, Delis, & Riley, 2001). Within the verbal domain, four studies have demonstrated that although deficits are noted in both letter and category fluency, deficits are greater on letter fluency tasks (Kodituwakku, Adnams, et al., 2006; Mattson & Riley, 1999; Rasmussen & Bisanz, 2009; Vaurio, et al., 2008). Similar findings were also reported within a sample of Native American Indian children: compared to controls, alcohol-affected children were impaired in letter fluency but unimpaired on category fluency (Aragon, Kalberg, et al., 2008).
