What is happening when a medium claims to be channeling or speaking to spirits? Believers claim that they are actually contacting non-physical entities, and that their channeled words and actions come from a place other than their brain. The skeptical interpretation is that the mediumship, of whatever flavor, is nothing more than a performance. The truth lies in the brain of the medium, and since we cannot read minds it seems there will always be room for interpretation.
This may be changing, however, as we develop the technology to peek directly at brain activity.
MORE: http://www.skepticblog.org/2012/11/19/studying-the-brains-of-mediums/
