Figure 1
Trial sequence. Participants were asked to remember the color of a retro-cued circle. During the retention interval, one of four colored probes was shown. Next, the participant was instructed to indicate the memory color on a color wheel.
Figure 2
(A-C) Linear mixed effects model results for pupil response during probe presentation; (D) behavioral response bias. In A-C, the dotted line represents probe offset, and significant differences between pupil responses are indicated with the horizontal green line (yellow-green: p < 0.05; green: p < 0.01; dark green: p < 0.001). (A) Linear mixed effects model testing the difference in pupil response for exact-match versus different probes. Different probe types resulted in initial stronger pupil constriction compared to exact-match probe types. (B) Linear mixed effects model testing the difference in pupil response for exact-match and between-category probe types. Between-category probe types resulted in a slower pupil recovery compared to exact-match probe types. (C) Model testing the difference between between- and within-category responses. No significant differences between pupil responses for within- and between-category were found. (D) Behavioral response bias. Individual lines represent individual participant responses. Memory bias is shown on the x-axis (positive bias means an error towards category centers, negative bias means error away from category centers). In D, the dotted line represents unbiased, veridical color reproductions.