Fig. 6. Visualization of task-specific distributions of discriminative biomarkers.

The rationality of the DL model decisions was verified by examining the peak activations in the task-specific aggregate saliency maps. The panels above present the axial slices of the aggregate saliency maps for each of the undertaken classification/regression tasks - a age and gender-based classification, b gender classification, c age regression and d mini-mental state examination (MMSE) regression. Brain regions determined as the most discriminative of the undertaken tasks by the validated DL models showed a high general correspondence with previous reports in neuroimaging literature.