Fig. 1.

Peer-reviewed research results published during the last 5 years reporting the usage of DL in detecting NLD from MRI data. The Scopus database (https://www.scopus.com/) was searched with search-strings containing keywords “Deep learning” and “MRI” in conjunction with each of the NLD (“Alzheimer’s”, “Parkinson’s”, and “schizophrenia”) and the obtained results were categorized basing on the DL architectures (a) and diseases (b). A. In the literature the CNN has been reported much more frequently in comparison to the RNN, LSTM, DNN, and AE. B. The main effort appears to cluster around AD in comparison to PD and SZ