FIGURE 4.

Relationship between cognitive function and the urge-to-cough (UTC), showing: a) the relationship between mini mental state examination (MMSE) score and log C_u (where C_u=concentration of citric acid at a threshold of UTC), which illustrates significant differences; b) a comparison of log C_u between the control group, the Alzheimer's disease (AD) group and the dementia with Lewy bodies (DLB) group. Log C_u in the DLB group was significantly higher than in the control group and the AD group (p₁=0.004, as adjusted for gender). Post hoc tests showed significant differences in log C_u between the DLB group and the control group or the AD group (p=0.008 and p=0.061, respectively).