Fig. 4.

Changes in pupil diameter to feedback on informative trials (choice of seasonal items) and uninformative trials (choice of items not seasonally specific). Older adults differentiate informative and uninformative feedback less, suggesting that they engage less in model-based updating than younger adults. Changes in pupil diameter are z-scored within individuals; lines indicate means within age groups. Shaded areas indicate SEs of mean individual pupil diameters within age groups. Early peaks before 1 second are not included in statistical analyses and reflected lateral positions of gain and loss feedback on the screen.