The strength of the pupil-size modulation is related to the strength of the behavioral cueing effect in response times (a; Exp. 1) and accuracy (b; Exp. 2).

a) Dots indicate participant bin means. Colors indicate different bins (see text for details). Regression line and slope CI are estimated with LMM and MCMC. b) Dots indicate participant means. Regression line and slope CI are estimated with linear regression. c) The strength of the pupil-size modulation as shown in a) and b) corresponds to the surface area between the attend-dark and attend-bright pupil-size traces in the 1000–2000 ms interval of the cue-target epoch. Intervals where the attend-bright trace fell above the attend-dark trace were counted as negative surface. The example shown here corresponds to a single data point in b), as indicated.