Figure 2.

Amygdala volumes of spider phobic patients and healthy controls. The central box shows the data between 25^th and 75^th quartiles, with the median represented by the line. The whiskers extend from the upper and lower quartiles to a distance of 1.5 interquartile range (IQR). Circles represent the outliers over 3 IQR below the 25^th or above the 75^th quartile. Relative amygdala volumes were calculated by the following formula: 100x(absolute amygdala volume in mm²/intracranial volume in mm²). a: boxplot comparing relative left amygdala volume; b: boxplot comparing relative right amygdala volume.