The results demonstrate that the association between perplexity and lexical frequency is significant and positive for the control LM (coeff: 0.563, p < 0.001) and negative for dementia LM (coeff: -0.543, p < 0.001).
it is currently unclear as to whether this level of accuracy is due to dementia-specific linguistic markers, or a result of markers of other significant differences between the case and control group such as age (x¯ = 71.4 vs. 63) and years of education (x¯= 12.1 vs. 14.3) (Becker et al., 1994)