David Marks is one of these critics, and he has some convincing critics of Sheldrake's claims. Mark's describes psychologist Tritchner's feeling on the subject to buttress his criticisms. Trichner's students told him they could feel when other students were looking at them in class. “Tritchner described the sensation as “a state of unpleasant tingling, which increases in volume and intensity until a movement that will relieve it becomes inevitable” (Tritcher 895). Tritchner decided he would investigate the claims made by his people