There are a number of theories as to how TFT works. A popular theory is that the tapping process scrambles the negative thought processes by activating different parts of the brain at the point you are thinking about the problem. Some believe it is purely distraction; however this doesn't explain how one tapping sequence can work whereas another doesn't. However there is an alternative theory that challenges the view of conventional medicine which assumes the mind and brain are the same thing and that emotional problems like anxiety and depression are caused by structural or chemical abnormalities in the brain which can only be corrected with drugs. Dr Callahan challenges this view that the mind and brain are separate. He theorises that the mind is contained in a sort of field which surrounds the physical body in the same way that an electric field envelops a live conductor. According to this theory, when we think of a problem we tune into a part of this field, called a 'thought field'. It is rather like tuning a radio into a radio station. Furthermore Dr Callahan believes unpleasant emotions are caused by negative information patterns in thought fields which he terms 'perturbations'. By tapping on the correct meridian points in the right order these perturbations are subsumed and the negative emotion disappears. In effect, with TFT we are picking the lock which controls negative emotions — we are entering a PIN code which turns off these problems.