Dyslexia: a deficit in visuo-spatial attention, not in phonological processing

Trends Cogn Sci. 2010 Feb;14(2):57-63. doi: 10.1016/j.tics.2009.12.003. Epub 2010 Jan 14.


Developmental dyslexia affects up to 10 per cent of the population and it is important to understand its causes. It is widely assumed that phonological deficits, that is, deficits in how words are sounded out, cause the reading difficulties in dyslexia. However, there is emerging evidence that phonological problems and the reading impairment both arise from poor visual (i.e., orthographic) coding. We argue that attentional mechanisms controlled by the dorsal visual stream help in serial scanning of letters and any deficits in this process will cause a cascade of effects, including impairments in visual processing of graphemes, their translation into phonemes and the development of phonemic awareness. This view of dyslexia localizes the core deficit within the visual system and paves the way for new strategies for early diagnosis and treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attention Deficit Disorder with Hyperactivity / complications
  • Attention Deficit Disorder with Hyperactivity / etiology*
  • Attention Deficit Disorder with Hyperactivity / pathology
  • Brain / physiopathology
  • Dyslexia / complications*
  • Humans
  • Nerve Net / physiopathology
  • Perceptual Disorders / complications
  • Perceptual Disorders / etiology*
  • Perceptual Disorders / pathology
  • Phonetics*
  • Reading*
  • Space Perception / physiology*