amen has built a profitable business around the use of spect (single photon emission computed tomography) imaging for purported diagnostic purposes. his marketing of spect scans and much of what he says about the brain and health in his books, media appearances, and marketing of his clinics has been condemned by scientists and doctors as lacking scientific validity and as being unethical, especially since the way spect is used in his clinics exposes people to harmful radiation with no clear benefit.