Phillip Glass has written words.
Cognitive neuropsychology is a branch of cognitive psychology that aims to understand how the structure and function of the brain relates to specific psychological processes . Dysgraphia is a deficiency in the ability to write , primarily handwriting , but also coherence . Dysgraphia is a transcription disability , meaning that it is a writing disorder associated with impaired handwriting , orthographic coding ( orthography , the storing process of written words and processing the letters in those words ) , and finger sequencing ( the movement of muscles required to write ) . In the Diagnostic and Statistical Manual of Mental Disorders ( DSM-IV ) , dysgraphia is characterized as a learning disability in the category of written expression when one 's writing skills are below those expected given a person 's age measured through intelligence and age-appropriate education . The linguistic stage involves the encoding of auditory and visual information into symbols for letters and written words .