http://cogprints.org/5043/ Dyslexia and Brain Scans: A Critique of Experimental Design The foundation of these studies rests on epistemic assumptions, undefined terms, and uncontrolled variables, and without rigorous, systematic definitions of critical terms and control of variables, these studies are essentially arguments based on popular opinion. Other conclusions are therefore possible, and there is no compelling reason to view the images as demonstrating a cause of dyslexia. Ferguson, Mr Jack Brain Imaging Jack Ferguson