Human brains envision real objects in a three-dimensional world. Due to this fact of viewing objects and understanding the nature of a three-dimensional world, the human brain can identify objects in different orientations, such as mirrored or backward, a term called mirror generalization. This has been tested in infants, children, and animals. On the other hand, reading alphabetical letters is a two-dimensional perception task. To learn to read, a person must be able to read letters with mirrored generalization, but this task is difficult in children with dyslexia. But children with dyslexia who have strong spatial skills early on can learn the skill of mirror generalization, but still cannot control its use, much like an on and off switch.