Fig. 5

Correlation of the significant principal components and age of onset of AD in the frontal lobe. Principal components exhibiting significant correlation with the age of onset of AD \(\left( |r|>0.5; P<0.05/N_{{{\rm ind}}}^r\right)\). A linear regression with 95% confidence bands is shown on the plots for better visualization of the correlations. The features extracted from AD patients in the right lateral orbital gyrus of the frontal lobe (a) and in the right anterior orbital gyrus of the frontal lobe (b) exhibit a significant difference with respect to the background estimated from control subjects, as confirmed also by the Student’s t-test on the distributions of the two patient categories with respect to a threshold age \({\mathcal{A}}\) (c, d).