Part B of the Trail Making Test, which assesses visual search, working memory, and cognitive flexibility (Chanraud et al., 2009). Alcoholics clinically asymptomatic for pontine signs of CPM reveal significant correlations between poorer verbal and nonverbal fluency production (tests long considered sensitive to lesions of lateral frontal cortex, Lezak, 1995; Kolb and Whishaw, 1996) and longer pontine relaxation times (Sullivan and Pfefferbaum, 2001). Regarding anatomical connectivity, it is possible that the relationships between fluency output and pontine relaxivity arise from compromise of frontal connections to central pontine sites (Schmahmann and Pandya, 1997).
