Figure 10.

Relevant regions for the brain age prediction based on 1% of the salience maps of individuals with an average age of 65 years overlayed to a random T1w MRI sample for each of the four CNN models. The individuals were randomly selected in the test dataset used in CNN1, according to their brain age difference and proximity to the average age of our sample (65 years). Each row represents the salience maps of one CNN model, where the columns show the same individual’s salience map in each of the four models. The SmoothGrad method was used to generate all salience maps. The brain age difference is shown in the top row of the image, going from −8 to +8 years. Overlaid salience map colours are normalized for each individual between 0 and 1.