The materialist theory that the mind is nothing but the activity of the brain makes it impossible that psychic phenomena should exist, or at least extremely unlikely. Therefore many materialists dismiss the possibility of psychic phenomena, and militant sceptics try to debunk the evidence for them. Nevertheless there is now much evidence that these phenomena really exist, as summaries for example in Dean Radin's book Entangled Minds: Extrasensory Experiences in a Quantum Reality, and Rupert Sheldrake's book The Sense of Being Stared At, And Other Unexplained Powers of Human Minds.
For a discussion of the evidence in relation to debates with sceptics, see Chris Carter's book Science and Psychic Phenomena: The Fall of The House of Sceptics and Robert McLuhan's book Randi's Prize.
Men Who Stare at Photons
Dean Radin's presentation at the EU 2013 conference, in which he reviews the history of scientific investigation into psychic phenomena, his research at IONS and the growing evidence.