High Quality Content by WIKIPEDIA articles! Thought Field Therapy, or TFT, is a fringe psychological treatment developed by an American psychologist, Roger Callahan. Its proponents say that it can heal a variety of mental and physical ailments through specialized "tapping" with the fingers at meridian points on the upper body and hands. There is no scientific evidence that TFT is effective, and the American Psychological Association has stated that it "lacks a scientific basis."