Fig. 4.

Standard deviation (a & c) of the original normal distributions that construct the psychometric functions shown in Fig. 3 and their corresponding distributions (b & d) for different stimulation conditions. (a & c) includes individual data along with their median. Standard deviation is σ as indicated in Eq. (1). Error bars indicate one standard error of mean. *p < 0.05 and **p < 0.01 (Bonferroni corrected).