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Danielle Paterno, Brian Keane, Sabine Kastner, Steven Silverstein; Is 20/20 vision good enough? Visual acuity differences within the normal range alter performance on contour grouping tasks. Journal of Vision 2014;14(10):64. doi: https://doi.org/10.1167/14.10.64.
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© ARVO (1962-2015); The Authors (2016-present)
Contour integration (CI) is a visual process that combines appropriately aligned and oriented elements into coherent boundaries and shapes. Collinear facilitation (CF) occurs when a low-contrast oriented element ("Gabor") becomes more visible when flanked by collinear high-contrast elements. Both processes rely at least partly on long-range horizontal connections in early visual cortex, and thus both have been extensively studied to understand visual cortical functioning in aging, development, and clinical disorders. Here, we ask: Can acuity differences within the normal range alter CI or CF? Method. To consider this question, we compared subjects with 20/20 vision to those with better-than-20/20 vision (Sharp-Perceivers) on two tasks. In the CI task, subjects detected the location of an integrated shape embedded in varying amounts of noise; in the CF task, subjects detected a low-contrast element flanked by collinear or orthogonal high-contrast elements. In each case, displays were scaled in size to modulate the visibility and spatial frequency of elements (4-12 cycles/deg). Results. We found that Sharp-Perceivers could integrate contours under noisier conditions than the 20/20 group especially for the high spatial frequency displays (p<.001). Collinear facilitation did not depend on acuity, but the 20/20 group exhibited overall higher contrast thresholds for the high spatial frequency displays (p<.05). Conclusion. These results suggest that small visual acuity differences within the normal range—equivalent to a one line difference on a vision chart—alters element detection and integration. Furthermore, simply ensuring that subjects have normal or corrected-to-normal vision is not sufficient when comparing groups on contour grouping or related tasks involving Gabors; visual acuity confounds also need to be considered.
Meeting abstract presented at VSS 2014
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