Undercounting features and missing features: evidence for a high-level deficit in strabismic amblyopia

Abnormal visual development in strabismic amblyopia drastically affects visual perception and properties of neurons in primary visual cortex (V1). To test the notion that amblyopia also has consequences for higher visual areas, we asked humans with amblyopia to count briefly presented features. Using the amblyopic eye, strabismic amblyopes counted inaccurately, markedly underestimating the number of features. This inaccuracy was not due to low-level considerations (blur, visibility, crowding, undersampling or topographical jitter), as they also underestimated the number of features missing from a uniform grid. Rather, counting deficits in strabismic amblyopes reflected a higher-level limitation in the number of features the amblyopic visual system can individuate.

[1]  A Treisman,et al.  Feature binding, attention and object perception. , 1998, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[2]  Earl L. Smith,et al.  Binocular interactions in striate cortical neurons of cats reared with discordant visual inputs , 1994, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[3]  L. P. O'Keefe,et al.  Neuronal Correlates of Amblyopia in the Visual Cortex of Macaque Monkeys with Experimental Strabismus and Anisometropia , 1998, The Journal of Neuroscience.

[4]  H. Onoe,et al.  Reduced activity in the extrastriate visual cortex of individuals with strabismic amblyopia , 1997, Neuroscience Letters.

[5]  A Bradley,et al.  Contrast sensitivity in anisometropic amblyopia. , 1981, Investigative ophthalmology & visual science.

[6]  M. Posner,et al.  Orienting of Attention* , 1980, The Quarterly journal of experimental psychology.

[7]  J. Cronly-Dillon,et al.  Vision and visual dysfunction. , 1994, Journal of cognitive neuroscience.

[8]  F. Gregory Ashby,et al.  Subitizing: Magical numbers or mere superstition? , 1992, Psychological research.

[9]  D. Levi,et al.  The effect of similarity and duration on spatial interaction in peripheral vision. , 1994, Spatial vision.

[10]  D M Levi,et al.  Spatio-temporal interactions in anisometropic and strabismic amblyopia. , 1977, Investigative ophthalmology & visual science.

[11]  A. Watson.  Probability summation over time , 1979, Vision Research.

[12]  Z. Pylyshyn,et al.  Why are small and large numbers enumerated differently? A limited-capacity preattentive stage in vision. , 1994, Psychological review.

[13]  R. Hess.  Developmental sensory impairment: amblyopia or tarachopia? , 1982, Human neurobiology.

[14]  Z. Pylyshyn,et al.  Multiple parallel access in visual attention. , 1994, Canadian journal of experimental psychology = Revue canadienne de psychologie experimentale.

[15]  Bettina L. Beard,et al.  Spatial scale shifts in amblyopia , 1994, Vision Research.

[16]  J. B.,et al.  The Power of Numerical Discrimination , 1871, Nature.

[17]  W. Singer,et al.  Reduced Synchronization in the Visual Cortex of Cats with Strabismic Amblyopia , 1994, The European journal of neuroscience.

[18]  Dennis M. Levi,et al.  Vernier acuity, crowding and amblyopia , 1985, Vision Research.

[19]  Scott T. Grafton,et al.  Neural Evidence Linking Visual Object Enumeration and Attention , 1999, Journal of Cognitive Neuroscience.

[20]  T. Wiesel.  The postnatal development of the visual cortex and the influence of environment. , 1982, Bioscience reports.

[21]  T. Wiesel.  Postnatal development of the visual cortex and the influence of environment , 1982, Nature.

[22]  Dennis M Levi,et al.  Position jitter and undersampling in pattern perception , 1999, Vision Research.

[23]  Z. Pylyshyn,et al.  Why are small and large numbers enumerated differently? A limited-capacity preattentive stage in vision. , 1994, Psychological review.

[24]  B. Dosher,et al.  External noise distinguishes attention mechanisms , 1998, Vision Research.

[25]  P. Cavanagh,et al.  Attentional resolution and the locus of visual awareness , 1996, Nature.

[26]  S. Klein,et al.  Spatial uncertainty and sampling efficiency in amblyopic position acuity , 1998, Vision Research.

[27]  R. Rafal,et al.  "Both" means more than "two": localizing and counting in patients with visuospatial neglect , 1999, Nature Neuroscience.

[28]  S. Klein,et al.  Sampling in spatial vision , 1986, Nature.

[29]  Michael Harpham.  December , 1855, The Hospital.

[30]  F. Campbell,et al.  The Magic Number 4 ± 0: A New Look at Visual Numerosity Judgements , 1976, Perception.

[31]  R S Harwerth,et al.  Residual binocular interactions in the striate cortex of monkeys reared with abnormal binocular vision. , 1997, Journal of neurophysiology.

[32]  R. F. Hess,et al.  The threshold contrast sensitivity function in strabismic amblyopia: Evidence for a two type classification , 1977, Vision Research.

[33]  C. Eriksen,et al.  Movement of attentional focus across the visual field: A critical look at the evidence , 1987, Perception & psychophysics.