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. Author manuscript; available in PMC: 2012 Sep 1.
Published in final edited form as: Nat Neurosci. 2012 Jan 8;15(3):463–S2. doi: 10.1038/nn.3021

Figure 1. Characteristics of crowding in peripheral vision.

Figure 1

(a) Demonstration of crowding: fixating on the red ‘−‘ it should be easy to identify the letter s on the left; the equidistant s on the right, which is flanked (crowded) by other letters, is much harder to identify. When fixation is shifted to the green ’+’, the formerly-crowded s becomes easier to identify. (b) The extent of crowding (“crowding zone”, orange polygons) can be estimated by measuring target-identification performance at peripheral locations (demarcated by *) with flankers placed at various relative positions around the target. The estimated zones have three robust signatures: they scale up linearly with eccentricity of the target (Bouma’s Law); they are markedly elongated along the axis connecting the target to the fovea (radial axis); when tested with a single flanker (green dotted contour), as opposed to a pair (orange solid contours), flankers that are more eccentric than the target are more effective in crowding the target than are flankers that are less eccentric. (a: adapted from REF [10]; b: adapted from REF [9])