Figure 2. The effect of choice on sampling behavior is mediated by confidence in experiment 1.

Participants were less likely to change their mind if they showed a strong sampling bias for their initially chosen option in the sampling phase. (A) Sampling bias in favour of the chosen option increases as a function of confidence in the initial choice. Confidence and sampling bias are both normalised at the participant level in this plot. (B) There is a significant main effect of choice on sampling time difference, such that an option is sampled for longer if it was chosen, and a significant interaction effect of Choice x Confidence, such that options chosen with high confidence are sampled for even longer. (C) There is a main negative effect of sampling bias on change of mind, such that participants were less likely to change their mind in the second decision phase (phase 3) the more they sampled their initially chosen option in the free sampling phase (phase 2). (B–C) Plotted are fixed-effect coefficients from hierarchical regression models predicting the sampling time (how long each patch was viewed in the sampling phase) difference between the left and right stimuli. Data points represent regression coefficients for each individual participant.

Figure 2—figure supplement 1. Confidence in the second choice is significantly predicted by trial difficulty (dot difference) and change of mind.

In experiment 1, it is also affected by sampling bias, such that the more time participants spent sampling the initially chosen stimulus, the more confidence they had in their second choice. Plotted are fixed-effect coefficients from hierarchical regression models predicting confidence ratings in the second choice phase. Data points represent regression coefficients for each individual participant.