The invention relates to a device for controlled modulation of physiological and pathological neuronal rhythmic activity in the brain by means of sensory stimulation, which is capable of diagnostically ascertaining functional disorders in the brain and of alleviating or eliminating the symptoms of a functional disruption. According to the invention, the device comprises a control unit (4), a stimulator (1) and at least one means for detecting brain activity, said means being connected to the control unit (1).