Field research has proven that mediums and mystici are often in an altered state of consciousness, when paranormal phenomena occur. This can vary from a complete trance to a lighter hypnagogical state, during which the medium relaxes his or her left cerebral hemisphere to induce a dreamlike state. Depending on the capacity to become unaware of reality, a deeper trance can be reached. Sensory perception definitely is an obstacle for this process. (cf Bergson) When the individual is aware of his ‘entourage’ and his or her imagination is restrained, any psychic and paranormal impressions are hampered. In 1975 Honorton, Braud and Parker developed a method to help the test person in the lab to reach the dreamlike state. At the beginning of the experiment, the test person is seated in a comfortable armchair and two hemispheres are placed over the eyes. Next, a weak, they shine a red light over the covered eyes and a set of headphones is placed on the person’s head. First, the test person can listen to a spoken relaxation tape, followed by a tape with some white noise. In the meantime, the sender randomly selects a set of four images (also videoclips or pieces of music) from a target pool. From the selected set, another ‘goal image’ is chosen. While the sender concentrates intensely on the ‘goal image’, the test person talks about his impressions. These impressions are taken down by an experimenter or are recorded on tape. After the session, the potential goals are presented to the test person, who then choses an image that is most similar to his description. Based on the descriptions given, irrespective critics afterwards have to choose the intended image from the original set. Eventually, the final results are compared with the actual ‘goal image’. Statistical evaluation will make clear whether the experiment was successful or not. For the moment, the results of the ganzfeldexperiment can still be considered as being significant. Furthermore, the meta-analyses show that the ganzfeldexperiment can be replicated. The significant results and ease of repetitiveness of the ganzfeldexperiment currently makes it to be the method most applied in the research on ESP.