Figure 6.

Energization signal in pupil rate is independent of choice bias effect. Control analysis extending the effects reported in de Gee et al. (2014) that pupil dilates faster when participants choose an option against their default bias, denoted as choice-bias effect (A). The energization effect depicted in Figure 3 is not related to the choice bias effect (B). A, Boxplots display the median (central line), 25th and 75th percentiles (bottom and top edges), and non-outlier low and high extreme values (bottom and top error bars). Blue lines show subjects whose effort slope is higher in effortful choice than in non-effortful choice, gray lines show subjects who show the opposite effect. Symbols indicate significance levels between two conditions: star for p < 0.001, triangle for p < 0.01, diamond for p < 0.05, ns for p > 0.05. B, Each data point represents a subject; p value represents significance level from robust regression.