Correlation and matching computations in random dot stereograms.

<p>a) A schematic representation of a half-matched random dot stereogram. Half the dots are correlated, half the dots are anticorrelated, resulting in a binocular correlation of 0. b) Psychometric functions reflecting the operation of hypothetical matching and pure correlation computations (recreated from Doi et al [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1004906#pcbi.1004906.ref014" target="_blank">14</a>]) as a function of dot match level. The pure correlation computation (blue line) signals reversed depth at a dot match level of 0 (fully anticorrelated), is at chance at a dot match level of 0.5 (half-matched) and performs perfectly at a dot match level of 1. The matching computation (green line) is at chance for anticorrelated stimuli and gradually increases to perfect performance with increasing percentage of matched dots. The horizontal line shows chance performance, and the vertical line marks a dot match level of 0.5, e.g. the half-matched stereogram shown in (a).