Visual field asymmetries in pattern discrimination: A sign of asymmetry in cortical visual field representation?

A visual field asymmetry is described relative to the discrimination of mirror symmetric bars with ramp-like luminance profiles. Along the vertical meridian the discrimination is better performed for patterns oriented parallel to the meridian than for patterns oriented orthogonally at all eccentricities tested (2-8 deg). Along the horizontal meridian, the preference for radially oriented stimuli is present at 2 deg from the fovea, but vanishes at larger eccentricities. The meridional asymmetry thus revealed psychophysically may reflect asymmetries in the representation of the vertical and horizontal meridians in the human visual cortex.

[1]  Ingo Rentschler,et al.  Loss of spatial phase relationships in extrafoveal vision , 1985, Nature.

[2]  Franklin H. McColgin,et al.  Movement Thresholds in Peripheral Vision , 1960 .

[3]  E. Switkes,et al.  Functional anatomy of macaque striate cortex. II. Retinotopic organization , 1988, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[4]  D M Levi,et al.  Peripheral hyperacuity: isoeccentric bisection is better than radial bisection. , 1987, Journal of the Optical Society of America. A, Optics and image science.

[5]  D. Hubel,et al.  The pattern of ocular dominance columns in macaque visual cortex revealed by a reduced silver stain , 1975, The Journal of comparative neurology.

[6]  A Fiorentini,et al.  Right-Hemisphere Superiority in the Discrimination of Spatial Phase , 1984, Perception.

[7]  D. V. van Essen,et al.  The pattern of interhemispheric connections and its relationship to extrastriate visual areas in the macaque monkey , 1982, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[8]  D. Hubel,et al.  Projection into the visual field of ocular dominance columns in macaque monkey , 1977, Brain Research.

[9]  D. Burr,et al.  Discrimination of spatial phase in central and peripheral vision , 1989, Vision Research.

[10]  A. Leventhal,et al.  Structural basis of orientation sensitivity of cat retinal ganglion cells , 1983, The Journal of comparative neurology.

[11]  A. Fiorentini,et al.  Perceptual learning specific for orientation and spatial frequency , 1980, Nature.

[12]  M. Banks,et al.  The effects of contrast, spatial scale, and orientation on foveal and peripheral phase discrimination , 1991, Vision Research.

[13]  L. Ling,et al.  Magnification factors and the organization of the human striate cortex. , 1988, Human neurobiology.

[14]  R. F. Hess,et al.  The contrast sensitivity gradient across the human visual field: With emphasis on the low spatial frequency range , 1989, Vision Research.

[15]  W. Levick,et al.  Analysis of orientation bias in cat retina , 1982, The Journal of physiology.

[16]  A. Leventhal,et al.  Retinal ganglion cell dendritic fields in old-world monkeys are oriented radially , 1986, Brain Research.

[17]  M. Banks,et al.  Sensitivity loss in odd-symmetric mechanisms and phase anomalies in peripheral vision , 1987, Nature.

[18]  J Rovamo,et al.  Resolution of gratings oriented along and across meridians in peripheral vision. , 1982, Investigative ophthalmology & visual science.

[19]  A Fiorentini,et al.  Interhemispheric transfer of visual information in humans: spatial characteristics. , 1987, The Journal of physiology.

[20]  A. Fiorentini,et al.  Learning in grating waveform discrimination: Specificity for orientation and spatial frequency , 1981, Vision Research.