The research focuses on the self-regulation of neurophysiological signals through reward learning and classical conditioning in healthy individuals as well as in neurological and psychiatric patients. Self-regulation of local brain activity utilizes state-of-the-art neurophysiological instrumentation such as real-time functional magnetic resonance imaging (rt-fMRI), magnetoencephalography (MEG), electroencephalography (EEG), and near-infrared spectroscopy (NIRS), electromyography (EMG). The volitional self-regulation of activity of circumscribed brain areas with neurofeedback affects behavior, neurorehabilitation, and psychiatric and psychological disorders. Furthermore, Brain Computer interfaces (BCI) utilize this methodology to provide paralyzed patients (e.g. with amytrophic lateral sclerosis) with the possibility to send messages and commands to the external world without using their muscles or language, thus enabling direct brain communication. Brain-Machine Interfaces (BMI) in severe chronic stroke allows rehabilitation of completely paralyzed upper limbs.