In the fight against Alzheimer's, epilepsy, schizophrenia and other diseases characterized by an imbalance in neuronal activity, there are chemical weapons, such as those that try to prevent the protein fragments known as beta-amyloid plaques from developing in the cerebral cortex , and physical, such as electrical stimulation that allow to restore the functionality of brain cells. This last resort, which has already been shown to be effective in modifying the activity of the cerebral cortex, is today a weapon of general intervention. Converting it to precision requires the development of individualized and predictive brain models that allow identifying where and how much to stimulate each patient. To achieve this, an international European team is working on the creation of virtual replicas of the most unknown organ in the body: the Neurotwin project. According to recent research, the decrease in power in the neuronal oscillations of the gamma band of the cerebral cortex (a pattern whose frequency ranges between 20 and 50 Hertz) favors the development of protein fragments related to Alzheimer's. Transcranial application of weak electrical currents has proven to be an effective and painless way to modulate brain activity without side effects. The objective is to create complete computational models of the brain with real data of living beings (human patients) and that allow to anticipate and specify the effects of non-invasive stimulation techniques on neurological mechanisms. "Never turn your back on a friend." - Alfred Hitchcock Part II The Neurotwin project is the successor to an initiative that encompasses many projects called Virtual Physiological Human, which was based on the idea of creating a complete model of a human being on a computer, to perform non-invasive tests at the computational level. Now the concept has been derived to "Digital Twin", which seeks not only to have an equal computational model for everyone, but to create "twin" digital models of each patient in order to be able to make personalized medicine from the genome of each individual. Specifically, in our project, we have focused on digital twin brains, which would be representations of patient brains created from data extracted with current neuroimaging and brain activity monitoring techniques. "Mirrors are used to see the face, Art to see the soul." - George Bernard Shaw Part III A digital twin is a computer system programmed in such a way that, receiving the same inputs as the physical object or process it is a twin of, it provides the same outputs. Characteristics of digital twin technology 1 Connectivity 2 Homogenization 3 Reprogrammable and intelligent 4 Digital traces "There is no light without shadows and no fullness of mind without imperfections. Life requires for its realization, not perfection, but fullness. Without imperfection, there is no progress or growth." - Carl Gustav Young