Congenital word blindness is a term used to describe poor readers. Morgan assumed that the disorder was congenital rather than acquired by postnatal injury or assault. Congenital word blindness was first thought to be caused by a defect in the angular gyrus of the left cerebral hemisphere, an area of the brain associated with visual memory of words. The condition, however, was later viewed as a problem with left-right orientation and stephosymbolia caused in part by a lack of cerebral dominance.