Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-24T08:42:05.090Z Has data issue: false hasContentIssue false

Contrast sensitivity in dyslexia

Published online by Cambridge University Press:  02 June 2009

Karen Gross-Glenn
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami
Bernt C. Skottun
Affiliation:
Skottun Research, 273 Mather Street, Piedmont
William Glenn
Affiliation:
FloridaAtlantic University, Boca Raton
Alex Kushch
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami
Robert Lingua
Affiliation:
Department of Ophthalmology, University of California, Irvine
Mark Dunbar
Affiliation:
Bascom Palmer Eye Institute, 900 N.W. 17th Street, Miami
Bonnie Jallad
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami
Herbert A. Lubs
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami
Bonnie Levin
Affiliation:
Division of Neuropsychology, Department of Neurology, University of Miami School of Medicine, Miami
Mark Rabin
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami
Lesley A. Parke
Affiliation:
445 Bellevue Avenue, Suite 302, Oakland
Ranjan Duara
Affiliation:
Mailman Center for Child Development, Department of Pediatrics, University of Miami, School of Medicine, Miami

Abstract

Contrast sensitivity was determined for dyslexic and normal readers. When testing with temporally ramped (i.e. stimuli with gradual temporal onsets and offsets) gratings of 0.6, 4.0, and 12.0 cycles/deg, we found no difference in contrast sensitivity between dyslexic readers and controls. Using 12.0 cycles/deg gratings with transient (i.e. abrupt) onsets and offsets, we found that dyslexic individuals had, compared to controls, markedly inferior contrast sensitivity at the shortest stimulus durations (i.e. 17, 34, and 102 ms). This deficit may reflect more sluggish temporal summation. There was no difference in sensitivity to 0.6 cycles/deg gratings with transient onsets and offsets. Under these conditions, the two groups showed a consistent and equal increase in sensitivity relative to the ramped baseline condition at 0.6 cycles/deg at the longer stimulus durations. This demonstrates that dyslexic readers have no deficit in their ability to detect stimulus transients, a finding which appears to be inconsistent with a transient system deficit. That detection of the low-frequency stimuli was mediated by the transient system is further indicated by the fact that these stimuli were more susceptible to forward masking than were the high-frequency stimuli. The effects of masking of both high and low spatial-frequency stimuli were about equal for dyslexic readers and controls. This is not in agreement with the transient system deficit theory, according to which one would expect there to be less masking of high spatial-frequency stimuli in the case of dyslexic readers.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Badcock, D. & Lovegrove, W. (1981). The effects of contrast, stimulus duration, and spatial frequency on visible persistence in normal and specifically disabled readers. Journal of Experimental Psychology 7, 495505.Google Scholar
Baumgardt, E. (1972). Threshold quantal problems. In Handbook of Sensory Physiology, VII/4, ed. Jameson, D. & Hurvich, L.M., pp. 2955. Berlin: Springer-Verlag.Google Scholar
Bloch, A. (1885). Expériences sur la vision. Comptes rendu des seances de la Societe de Biologie (Paris) 37, 493495.Google Scholar
Breitmeyer, B.G. (1975). Simple reaction time as a measure of the temporal response properties of transient and sustained channels. Vision Research 15, 14111412.CrossRefGoogle ScholarPubMed
Breitmeyer, B.G. (1993). The roles of sustained (P) and transient (M) channels in reading and reading disability. In Facets of Dyslexia and its Remediation, ed. Wright, S.F. & Groner, R., pp. 1331. Amsterdam, The Netherlands: Elsevier Science Publishers.CrossRefGoogle Scholar
Breitmeyer, B.G. & Ganz, L. (1976). Implications of sustained and transient channels for theories of visual pattern masking, saccadic suppression and information processing. Psychological Review 83, 136.CrossRefGoogle ScholarPubMed
Breitmeyer, B.G. & Ganz, L. (1977). Temporal studies with flashed gratings: Inferences about human transient and sustained channels. Vision Research 17, 861865.CrossRefGoogle ScholarPubMed
Brooks, B.A. & Fuchs, A.F. (1975). Influence of stimulus parameters on visual sensitivity during saccadic eye movement. Vision Research 15, 13891398.CrossRefGoogle ScholarPubMed
Di Lollo, V., Hanson, D. & McIntyre, J.S. (1983). Initial stages of visual information processing in dyslexia. Journal of Experimental Psychology: Human Perception and Performance 9, 923935.Google ScholarPubMed
Finucci, J.M., Guthrie, J.T., Childs, A.L., Abbey, H. & Childs, B. (1976). The genetics of specific reading disability. Annals of Human Genetics 40, 123.CrossRefGoogle ScholarPubMed
Geiger, G. & Lettvin, J.Y. (1987). Peripheral vision in persons with dyslexia. The New England Journal of Medicine 316, 12381243.CrossRefGoogle ScholarPubMed
Graham, C.H. & Kemp, E.H. (1938). Brightness discrimination as a function of the duration of the increment in intensity. Journal of General Physiology 21, 635650.CrossRefGoogle ScholarPubMed
Gray, W.S. (1967). Gray Oral Reading Test. Indianapolis, Indiana: Bobbs-Merrill Co. Inc.Google Scholar
Green, M. (1981). Spatial frequency effects in masking by light. Vision Research 21, 861866.CrossRefGoogle ScholarPubMed
Green, M. (1984). Masking by light and the sustained-transient dichotomy. Perception and Psychophysics 35, 519535.CrossRefGoogle ScholarPubMed
Gross, K., Rothenberg, S., Schottenfeld, S. & Drake, C. (1978). Duration thresholds for letter identification in left and right visual fields for normal and reading-disabled children. Neuropsychologia 16, 709715.CrossRefGoogle ScholarPubMed
Gross-Glenn, K., Lewis, D.C., Smith, S.D. & Lubs, H.A. (1985). Phenotype of adult familial dyslexia: Reading of visually transformed texts and nonsense passages. International Journal of Neuroscience 28, 4959.CrossRefGoogle ScholarPubMed
Gross-Glenn, K., Jallad, B., Novoa, L., Helgren-Lempesis, V. & Lubs, H.A. (1990). Nonsense passage reading as a diagnostic aid in the study of adult familial dyslexia. Reading and Writing: An Interdisciplinary Journal 2, 161173.CrossRefGoogle Scholar
Herrick, R.M. (1956). Foveal luminance discriminations as a function of the duration of the decrement or increment in luminance. Journal of Comparative Physiological Psychology 49, 437443.CrossRefGoogle ScholarPubMed
Jastak, J.F. & Jastak, S. (1978). Wide Range Achievement Test. Wilmington, Delaware: Jastak Associates.Google Scholar
Jastak, J.F. & Wilkinson, G.S. (1984). Wide Range Achievement Test-Revised. Wilmington, Delaware: Jastak Associates.Google Scholar
Keller, M. (1941). The relation between critical duration and intensity in brightness discrimination. Journal of Experimental Psychology 28, 407418.CrossRefGoogle Scholar
Kulikowski, J.J. & Tolhurst, D.J. (1973). Psychophysical evidence for sustained and transient detectors in human vision. Journal of Physiology (London) 232, 149162.CrossRefGoogle ScholarPubMed
Legge, G. (1978). Sustained and transient mechanisms in human vision: Temporal and spatial properties. Vision Research 18, 6981.CrossRefGoogle ScholarPubMed
Livingstone, M.S., Rosen, G.D., Drislane, F.W. & Galaburda, A.M. (1991). Physiological and anatomical evidence for a magnocellular defect in developmental dyslexia. Proceedings of the National Academy of Sciences of the U.S.A. 88, 79437947.CrossRefGoogle ScholarPubMed
Lovegrove, W. & Brown, C. (1978). Development of information processing in normal and disabled readers. Perceptual and Motor Skills 46, 10471054.CrossRefGoogle ScholarPubMed
Lovegrove, W., Billing, G. & Slaghuis, W. (1978). Processing of visual contour orientation information in normal and disabled reading children. Cortex 14, 268278.CrossRefGoogle ScholarPubMed
Lovegrove, W.J., Bowling, A., Badcock, D. & Blackwood, M. (1980 a). Specific reading disability: Differences in contrast sensitivity as a function of spatial frequency. Science 210, 439440.CrossRefGoogle ScholarPubMed
Lovegrove, W.J., Heddle, M. & Slaghuis, W. (1980 b). Reading disability: Spatial frequency specific deficits in visual information store. Neuropsychologia 18, 111115.CrossRefGoogle ScholarPubMed
Lovegrove, W., Martin, F., Bowling, A., Blackwood, M., Badcock, D. & Paxton, S. (1982). Contrast sensitivity functions and specific reading disability. Neuropsychologia 20, 309315.Google Scholar
Lovegrove, W., Martin, F. & Slaghuis, W. (1986 a). A theoretical and experimental case for a visual deficit in specific reading disability. Cognitive Neuropsychology 3, 225267.CrossRefGoogle Scholar
Lovegrove, W., Slaghuis, W., Bowling, A., Nelson, P. & Geeves, E. (1986 b). Spatial frequency processing and the prediction of reading ability: A preliminary investigation. Perception and Psychophysics 40, 440444.CrossRefGoogle ScholarPubMed
Lovegrove, W.J., Garzia, R.P. & Nicholson, S.B. (1990). Experimental evidence for a transient system deficit in specific reading disability. American Optometric Association Journal 61, 137146.Google ScholarPubMed
Lovegrove, W. (1991). Spatial frequency processing in dyslexic and normal readers. In Vision and Visual Dyslexia, ed. Stein, J.F., pp. 148154. Boca Raton, Florida: CRC Press, Inc.Google Scholar
Manis, F.R. & Morrison, F.J. (1982). Processing of identity and position information in normal and disabled readers. Journal of Experimental Child Psychology 33, 7486.CrossRefGoogle ScholarPubMed
Martin, F. & Lovegrove, W. (1984). The effects of field size and luminance on contrast sensitivity differences between specifically reading disabled and normal children. Neuropsychologia 22, 7377.CrossRefGoogle ScholarPubMed
Martin, F. & Lovegrove, W. (1987). Flicker contrast sensitivity in normal and specifically disabled readers. Perception 16, 215221.CrossRefGoogle ScholarPubMed
Martin, F. & Lovegrove, W.J. (1988). Uniform-field flicker masking in control and specifically disabled readers. Perception 17, 203214.CrossRefGoogle ScholarPubMed
Matin, E. (1974). Saccadic suppression: A review and an analysis. Psychological Bulletin 81, 899917.CrossRefGoogle ScholarPubMed
May, J.G., Williams, M.C. & Dunlap, W.P. (1988). Temporal order judgements in good and poor readers. Neuropsychologia 26, 917924.CrossRefGoogle ScholarPubMed
Oldfield, R.C. (1971). The assessment and analysis of handedness: The Edinburgh Inventory. Neuropsychologia 9, 97113.CrossRefGoogle ScholarPubMed
Parke, L.A. (1993). Visual hyperacuity in dyslexia. Ph.D. Dissertation, University of California, Berkeley.Google Scholar
Rayner, K. (1978). Eye movements in reading and information processing. Psychological Bulletin 85, 618660.CrossRefGoogle ScholarPubMed
Robson, J.G. (1966). Spatial and temporal contrast-sensitivity functions of the visual system. Journal of the Optical Society of Amerìca 56, 11411142.CrossRefGoogle Scholar
Slaghuis, W.L. & Lovegrove, W. (1984). Flicker masking of spatial-frequency-dependent visible persistence and specific reading disability. Perception 13, 527534.CrossRefGoogle ScholarPubMed
Stanley, G. & Hall, R. (1973). Short-term visual information processing in dyslexics. Child Development 44, 841844.Google ScholarPubMed
Taylor, M.M. & Creelman, C.D. (1967). PEST: Efficient estimates on probability functions. Journal of the Acoustical Society of America 41, 782787.Google Scholar
Tolhurst, D.J. (1975 a). Reaction times in the detection of gratings by human observers: A probabilistic mechanism. Vision Research 15, 11431149.CrossRefGoogle ScholarPubMed
Tolhurst, D.J. (1975 b). Sustained and transient channels in human vision. Vision Research 15, 11511155.CrossRefGoogle ScholarPubMed
van der Velden, H. (1944). Over het antaal lichtquanta dat notig es for en licht prickel bij dat menselyk oog. Physica 11, 179189.CrossRefGoogle Scholar
Vellutino, F.R., Steger, B.M., Moyer, S.C., Harding, C.J. & Niles, J.A. (1977). Has the perceptual deficit theory lead us astray? Journal of Learning Disabilities 10, 375385.CrossRefGoogle Scholar
Victor, J.D., Conte, M.M., Burton, L. & Nass, R.D. (1993). Visual evoked potentials in dyslexics and normals: Failure to find a difference in transient or steady-state responses. Visual Neuroscience 10, 939946.CrossRefGoogle ScholarPubMed
Volkman, F.C. (1986). Human visual suppression. Vision Research 26, 14011416.CrossRefGoogle Scholar
Volkman, F.C., Schick, A.M.L. & Riggs, L.A. (1968). Time course of visual inhibition during voluntary saccades. Journal of the Optical Society of America 58, 562569.CrossRefGoogle Scholar
Wechsler, D. (1981). Wechsler Adult Intelligence Scale-Revised. San Antonio, Texas: Psychological Corporation, Harcourt Brace Jovanovich, Inc.Google Scholar
Wiederholt, J.L. & Bryant, B.R. (1986). Gray Oral Reading Test — Revised. Austin, Texas: Pro-Ed.Google Scholar
Williams, M.C., Molinet, K. & LeCluyse, K. (1989). Visual masking as a measure of temporal processing in normal and disabled readers. Clinical Vision Sciences 4, 137144.Google Scholar
Zuber, B.L., Stark, L. & Lorber, M. (1966). Saccadic suppression of the pupillary light reflex. Experimental Neurology 14, 351370.Google Scholar