Elsevier

Cortex

Volume 32, Issue 3, September 1996, Pages 413-438
Cortex

Visual and Language Processing Disorders are Concurrent in Dyslexia and Continue into Adulthood

https://doi.org/10.1016/S0010-9452(96)80002-5Get rights and content

Abstract

A recent study by Slaghuis, Lovegrove and Davidson (1994) found that visual and language processing differences were concurrent in a group of preadolescent dyslexics. In the present study, two experiments are reported that investigate the concurrence and continuity of visual and language processing differences in groups of young and adult dyslexics on a measure of visual processing and a measure of phonological coding. The visual processing task in the present experiments was a measure of Ternus apparent movement which was used as an index of the duration of visible persistence. Ternus apparent movement is multistable and provides two mutually exclusive and easily distinguishable percepts for the observer, referred to as ‘element’ and ‘group’ movement, that are highly dependent on the temporal interval between frame 1 and frame 2 of the display. The language processing task in the present experiments was a test of phonological coding measured using a non-word test of 100 orthographically legal non-words. The results of the first experiment showed that in comparison to normal readers the young dyslexic participants showed a significant reduction in Ternus ‘group movement’ and a significant reduction in the pronunciation of non-words. In a second experiment, Ternus apparent movement and performance on the non-word test was measured in groups of adult dyslexic and normal readers in order to investigate whether the visual and language processing differences found in young dyslexics were also present in adult dyslexics. The results showed that adult dyslexics also have a significant reduction in Ternus ‘group movement’ and a significant reduction in the ability to pronounce non-words similar to that found in the young dyslexic group in Experiment 1. The significant reduction in Ternus ‘group movement’ in dyslexic participants was explained in terms of an increase in the duration of visible persistence and was shown to be consistent with evidence for a transient system disorder. The combined results show that visual and language processing differences are concurrent in dyslexia and continue into adulthood.

References (99)

  • J.T. Petersik et al.

    Factors controlling the competing sensations produced by a bistable stroboscopic display

    Vision Research

    (1979)
  • W. Singer et al.

    Inbibitory interaction between X and Y units in the cat lateral geniculate nucleus

    Brain Research

    (1973)
  • R. Shapley et al.

    Cat and monkey retinal ganglion cells and their visual functional roles

    Trends in Neurosciences

    (1986)
  • W.L. Slaghuis et al.

    Spatial frequency mediated visible persistence and reading disability

    Brain and Cognition

    (1985)
  • W.L. Slaghuis et al.

    Visual and language processing deficits are concurrent in dyslexia

    Cortex

    (1993)
  • P. Tallal

    Auditory temporal perception, phonics, and reading disabilities in children

    Brain and Language

    (1980)
  • P. Tallal et al.

    Identification of language impaired children on the basis of rapid perception of production skills

    Brain and Language

    (1985)
  • D.J. Tolhurst

    Sustained and transient channels in human vision

    Vision Research

    (1975)
  • H.R. Wilson

    Spatio-temporal characterisation of a transient mechanism in the human visual system

    Vision Research

    (1980)
  • S.M. Anstis

    Apparent movement

  • D.R. Badcock et al.

    The effect of contrast, stimulus duration and spatial frequency on visible persistence in normal and specifically disabled readers

    Journal of Experimental Psychology: Human Perception and Performance

    (1981)
  • D.R. Badcock et al.

    Masking of uniform-field flicker: some practical problems

    Perception

    (1987)
  • D.J. Bakker et al.

    Temporal order in normal and disturbed reading

  • C.J. Bassi et al.

    Clinical implications of parallel visual pathways

    Journal of the American Optometric Association

    (1990)
  • A. Bowling et al.

    The effect of spatial frequency on the persistence of gratings

    Perception & Psychophysics

    (1980)
  • O.J. Braddick

    Low-level and high-level processes in apparent movement

    Philosophical Transactions of the Royal Society of London, Series B

    (1980)
  • O.J. Braddick

    Adlard Apparent motion and the motion detector

  • J.R. Brannan et al.

    The effect of age and reading ability on flicker threshold

    Clinical Vision Sciences

    (1988)
  • B.G. Breitmeyer

    Unmasking visual masking: A look at the ‘why’ behind the veil of the ‘how’

    Psychological Review

    (1980)
  • B.G. Breitmeyer

    Sensory masking, persistence, and enhancement in visual exploration and reading

  • B.G. Breitmeyer

    Visual Masking: An Integrative Approach

    (1984)
  • B.G. Breitmeyer

    A visually based deficit in specific reading disability

    The Irish Journal of Psychology

    (1989)
  • B.G. Breitmeyer

    The roles of sustained and transient channels in reading and reading disability

  • B.G. Breitmeyer et al.

    Implications of sustained and transient channels for theories of visual pattern masking, saccadic suppression and information processing

    Psychological Review

    (1976)
  • B.G. Breitmeyer et al.

    Visual persistence and the effect of eccentric viewing, element size, and frame duration on bistable stroboscopic motion percepts

    Perception and psychophysics

    (1986)
  • G.T. Buswell

    Fundamental reading habits: A study of their development

  • M. Coltheart

    Iconic memory and visible persistence

    Perception and Psychophysics

    (1980)
  • A.M. Derrington et al.

    Spatial and temporal contrast sensitivities of neurones in lateral geniculate nucleus of macaque

    Journal of Physiology

    (1984)
  • D.D. Duane

    A neurological overview of specific language disability for the non-neurologist

    Bulletin of the Orton Society

    (1974)
  • V. Di Lollo et al.

    Initial stages of visual information processing in dyslexia

    Journal of Experimental Psychology; Human Perception and Performance

    (1983)
  • C. Enroth-Cugell et al.

    The contrast sensitivity of retinal ganglion cells of the cat

    Journal of Physiology

    (1966)
  • B. Erdmann et al.

    Psychologische Untersuchungen fiber das Lesen

    (1898)
  • R.P. Garzia et al.

    Vision and reading I: Neuroanatomy and electrophysiology

    Journal of Optometric Vision Development

    (1993)
  • G. Geiger et al.

    Peripheral vision in persons with dyslexia

    The New England Journal of Medicine

    (1987)
  • R.N. Haber et al.

    Direct measures of the apparent duration of a flash

    Canadian Journal of Psychology

    (1970)
  • R. Hill et al.

    One word at a time: A solution to the visual deficit in the specific reading disabled

  • M. Jackson

    Reading disability, A case of reading malfunctioning: a program and therapy

    Australian Journal of Remedial Education

    (1976)
  • A.F. Dorm

    The cognitive and neuropsychological basis of developmental dyslexia

    Cognition

    (1979)
  • Cited by (42)

    • Visual-processing deficits in children with neurofibromatosis type 1: A clinical marker of reading difficulties: Vision and reading in NF1 children

      2022, European Journal of Paediatric Neurology
      Citation Excerpt :

      The magnocellular system (M-system) is assumed to be involved in low-spatial- and high-temporal-frequency processing, whereas the parvocellular system (P-system) is most sensitive to high-spatial and low-temporal frequencies. Slaghuis et al. [31] have referred to the P-sustained-system as the determinant of what a visual stimulus is, and the M-transient-system of where a visual stimulus is. P-system has also been associated with foveal vision, and M-system with parafoveal and peripheral vision.

    • Reading Comprehension and PASS Theory

      2015, Cognition, Intelligence, and Achievement: A Tribute to J. P. Das
    • Auditory and visual stream segregation in children and adults: An assessment of the amodality assumption of the 'sluggish attentional shifting' theory of dyslexia

      2009, Brain Research
      Citation Excerpt :

      At long intervals, the elements in the Ternus display are perceived as moving together as a whole (‘group movement’), while at shorter intervals only one element appears to be moving (‘element movement’). However, results were inconsistent: some authors found that dyslexic participants were impaired in the task (Cestnick and Coltheart, 1999; Slaghuis et al., 1996) but others did not (Davis et al., 2001). Finally, the Finnish team of Laasonen investigated visual, auditory and tactile segregation rate with temporal processing acuity tasks in dyslexic children (Laasonen et al., 2001) and young adults (Laasonen et al., 2001).

    View all citing articles on Scopus
    a

    Walter L. Slaghuis, Department of Psychology, University of Tasmania, GPO Box 252C, Hobart, Tasmania, 7001, Australia.

    View full text