The brain is the most complex part of the body. It has several kinds of waves, namely the alpha, beta ,theta and delta. Alpha waves, which signify conscious awareness, are the bridge to the unconscious, which is represented by the lower frequencies, theta and delta. When one comes close to unconscious memories during deep meditation, the theta activity tends to increase. In order to have conscious access to and remembrance of the unconscious content, alpha waves must be present in the EEG. Without alpha, the unconscious content remains unconscious. Mental tensions, excitement and anxiety cause an increase in both amplitude and frequency of the beta rhythms. Delta waves are associated with the deepest states of consciousness. Some consider that delta signifies contact with the collective unconscious. Delta rhythms combined with alpha are known to reflect inner intuitive empathetic radar, a kind of sixth sense.