Fixation Control and Antisaccades in Dyslexia

  • Monica Biscaldi
  • Stefan Gezeck
  • Burkhart Fischer
Chapter

Abstract

While we are reading our eyes are driven by a combination of visual and linguistic properties of the text and by shifts of attention along the text. These cognitive factors influence the cortical-subcortical brain circuitries that basically control saccade programming. Cognitive strategies and saccade programming determine together how intensively a target is fixated, how efficiently attentional selection processes are working, and where and when the eyes will move next (Vitu et al. 1995). The hypothesis of a basic dysfunction in eye movement control in dyslexia independent of linguistic difficulties has been controversely discussed during the past (Stark et al. 1991). Our studies, however, have shown that the reflexive component of the saccadic system (measured in tasks requiring saccades to suddenly appearing targets) is underdeveloped in many dyslexic subjects (Biscaldi et al. 1998). Since fixation control, i.e. the ability of suppressing reflexive saccades, and voluntary saccade generation were found to develop with different speed in a standard population between 8 and 20 years of age (Fischer et al. 1997), we investigated the control of voluntary vs. reflexive saccades in dyslexics.

Keywords

Antisaccade Task Express Saccade Fixation Control Reflexive Saccade Anti Saccade Task 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Biscaldi M, Gezeck S, Stuhr V (1998) Poor saccadic control correlates with dyslexia. Neuropsychologia, in pressGoogle Scholar
  2. Fischer B, Biscaldi M, Gezeck S (1997) On the development of voluntary and reflexive components in human sac-cade generation. Brain Res 754: 285–297PubMedCrossRefGoogle Scholar
  3. McDowell JE, Clementz BA (1997) The effect of fixation condition manipulations on antisaccade performance in schizophrenia: studies of diagnostic specificity. Exp Brain Res 115: 333–344PubMedCrossRefGoogle Scholar
  4. Munoz DP, Goldring JE, Hampton KA, Moore KD (1997) Control of purposive saccadic eye movements and visual fixation in children with attention deficit hyperactivity disorder. Proceedings of the 9th ECEM in Ulm, p80Google Scholar
  5. Rivaud S, Müri RM, Gaymard B, Vermesch AI, Pierrot-DeScilligny C (1994) Eye movement disorders after frontal eye field lesions in humans. Exp Brain Res 102: 110–120PubMedCrossRefGoogle Scholar
  6. Stark LW, Giveen SC, Terdiman JF (1991) Specific dyslexia and eye movements. In: Stein JF (ed) Vision and visual dyslexia (Vision and visual dysfunction, Vol. 13). Macmillan, London pp 203–232Google Scholar
  7. Vitu F., O’Regan J.K., Inhoff A.W., Topolski R. (1995) Mindless reading: Eye-mevement characteristics are similar in scanning letter strings and reading text. Perception & Psychophysics 57: 352–364CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • Monica Biscaldi
    • 1
  • Stefan Gezeck
    • 1
  • Burkhart Fischer
    • 1
  1. 1.Brain Research UnitFreiburgGermany

Personalised recommendations