Publication date
2009Keyword
Orientation discriminationAmblyopia
Spatial scale
Position
Eccentricity
Motion
Angle discrimination
Deviation detection
Peripheral vision
Peer-Reviewed
yes
Metadata
Show full item recordAbstract
In normal vision, detecting a kink (a change in orientation) in a line is scale invariant: it depends solely on the length/width ratio of the line (D. Whitaker, D. M. Levi, & G. J. Kennedy, 2008). Here we measure detection of a change in the orientation of lines of different length and blur and show that strabismic amblyopia is qualitatively different from normal foveal vision, in that: 1) stimulus blur has little effect on performance in the amblyopic eye, and 2) integration of orientation information follows a different rule. In normal foveal vision, performance improves in proportion to the square root of the ratio of line length to blur (L: B). In strabismic amblyopia improvement is proportional to line length. Our results are consistent with a substantial degree of internal neural blur in first-order cortical filters. This internal blur results in a loss of scale invariance in the amblyopic visual system. Peripheral vision also shows much less effect of stimulus blur and a failure of scale invariance, similar to the central vision of strabismic amblyopes. Our results suggest that both peripheral vision and strabismic amblyopia share a common bottleneck in having a truncated range of spatial mechanisms-a range that becomes more restricted with increasing eccentricity and depth of amblyopia.Version
No full-text available in the repositoryCitation
Levi, D. M., Whitaker, D., and Provost, A. (2009). Amblyopia masks the scale invariance of normal central vision. Journal of Vision, Vol. 9, No. 1, pp. 1-11.Link to Version of Record
https://doi.org/10.1167/9.1.22Type
Articleae974a485f413a2113503eed53cd6c53
https://doi.org/10.1167/9.1.22