1. A method for determining a location of electrical activity or hyperactivity of nerve cells in an anatomical structure of a body, comprising: generating an electrical conductivity model of the anatomical structure; detecting electrical signals via at least one input electrode; using the electrical conductivity model and the detected electrical signals to determine a location or locations of the electrical or hyper activity in the anatomical structure; and outputting electrical signals to the anatomical body structure via at least one output electrode, wherein the intensity and/or form of said output signals is ascertained using the electrical conductivity model.