Fig 2. Prior weighting and apathy.

A) Estimates of prior weighting, obtained through a linear mixed effects model of estimation errors against performance errors. For the Parkinson’s disease group, the grey lines indicate within-subject change in prior weighting from placebo to atomoxetine. Box-plot elements: centre line, median; box limits, first and third quartiles; whiskers, most extreme observations (all within 1.5 × interquartile range from the box limits). B) The relationship between apathy and prior weighting, adjusted for the effects of group and task performance variability (i.e., partial residuals). Note that observations with identical questionnaire scores were horizontally jittered to avoid overlaid dots.