TY - JOUR
T1 - Is 20/20 vision good enough? Visual acuity differences within the normal range predict contour element detection and integration
AU - Keane, Brian P.
AU - Kastner, Sabine
AU - Paterno, Danielle
AU - Silverstein, Steven M.
N1 - Funding Information:
This work was supported by a National Research Service Award (F32MH094102) to B.P.K. Special thanks to Timur Suhail-Sindhu and Genna Erlikhman for help with data collection and coding, respectively.
Publisher Copyright:
© 2014, Psychonomic Society, Inc.
PY - 2014
Y1 - 2014
N2 - Contour integration (CI) combines appropriately aligned and oriented elements into continuous boundaries. Collinear facilitation (CF) occurs when a low-contrast oriented element 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 predict CI or CF? To consider this question, we measured binocular visual acuity and compared subjects with 20/20 vision to those with better-than-20/20 vision (SharpPerceivers) on two tasks. In the CI task, subjects located 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 element visibility and spatial frequency (4–12 cycles/deg). SharpPerceivers could integrate contours under noisier conditions than the 20/20 group (p =.0002), especially for high spatial frequency displays. Moreover, although the two groups exhibited similar collinear facilitation, SharpPerceivers could detect the central target with lower contrast at high spatial frequencies (p <. 05). These results suggest that small acuity differences within the normal range—corresponding to about a one line difference on a vision chart—strongly predict element detection and integration. Furthermore, simply ensuring that subjects have normal or corrected-to-normal vision is not sufficient when comparing groups on contour tasks; visual acuity confounds also need to be ruled out.
AB - Contour integration (CI) combines appropriately aligned and oriented elements into continuous boundaries. Collinear facilitation (CF) occurs when a low-contrast oriented element 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 predict CI or CF? To consider this question, we measured binocular visual acuity and compared subjects with 20/20 vision to those with better-than-20/20 vision (SharpPerceivers) on two tasks. In the CI task, subjects located 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 element visibility and spatial frequency (4–12 cycles/deg). SharpPerceivers could integrate contours under noisier conditions than the 20/20 group (p =.0002), especially for high spatial frequency displays. Moreover, although the two groups exhibited similar collinear facilitation, SharpPerceivers could detect the central target with lower contrast at high spatial frequencies (p <. 05). These results suggest that small acuity differences within the normal range—corresponding to about a one line difference on a vision chart—strongly predict element detection and integration. Furthermore, simply ensuring that subjects have normal or corrected-to-normal vision is not sufficient when comparing groups on contour tasks; visual acuity confounds also need to be ruled out.
KW - Perceptual organization
KW - Visual acuity
KW - Visual perception
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U2 - 10.3758/s13423-014-0647-9
DO - 10.3758/s13423-014-0647-9
M3 - Article
C2 - 24845876
AN - SCOPUS:84939884735
SN - 1069-9384
VL - 22
SP - 121
EP - 127
JO - Psychonomic Bulletin and Review
JF - Psychonomic Bulletin and Review
IS - 1
ER -