Peripheral hyperacuity: isoeccentric bisection is better than radial bisection.

Y L Yap; D M Levi; S A Klein

doi:10.1364/josaa.4.001562

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Peripheral hyperacuity: isoeccentric bisection is better than radial bisection.

Y L Yap·D M Levi·S A Klein

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Abstract

Performance of three-dot bisection was determined as a function of orientation for a variety of feature separations and field meridians at eccentricities of 0-10 deg for two observers. The dot stimuli and separations were scaled in size to compensate for eccentricity. The precision of three-dot bisection was found to depend on the direction of test-feature offset. In the fovea, horizontal and vertical bisections were better than oblique bisections, while at eccentricities of 5-20 deg, isoeccentric (on a tangent to a circle of a given eccentricity) bisection was better than radial bisection. The direction of offset was more important than the orientation of the stimulus. Large separations showed a stronger effect than small separations. The anisotropy of bisection appears different from the meridional effect for resolution and is unlikely to be simply related to a local anisotropy of the cortical magnification factor.

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Discrimination, Psychological Fovea Centralis Humans Macula Lutea Sensory Thresholds Visual Acuity Visual Perception Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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Y L Yap, D M Levi, S A Klein. 1987. Peripheral hyperacuity: isoeccentric bisection is better than radial bisection.. https://doi.org/10.1364/josaa.4.001562

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