Fig. 2. Mean (± s.e.m.) proportion choice of the constant reward in conditions of the risk-sensitivity experiment in which variability was in reward volume. For each condition, the values of the coefficient of variation (CV) of the variable reward distribution, whether it included zero rewards, the variance (µl²) and the skew (probability of the low reward) are listed. Distributions are positively skewed for skew >0.5. The broken line represents indifference. Different lowercase letters represent means that are significantly different from each other (P<0.05, Tukey's test). Numbers in the columns are sample sizes.