The stroke that Carleton suffered in 1985 damaged the portion of her brain where words and speech are processed, leaving her with a condition known as aphasia, or the inability to use language. While she is able to comprehend much of what people say to her, she cannot formulate her thoughts into coherent phrases or sentences.
Using the computer program, she can select from hundreds of pictures that represent people, objects, actions, and descriptive qualities and arrange them in sequence to communicate thought, obviating the need to use words.