Figure 4.

a–c, fMRI results: parametric correlation with Δ-WTA and Δ-WTP. Striatal activations correlated with an increase in subjects' selling prices (Δ-WTA) and a decrease in subjects' buying prices (Δ-WTP) in reference to the evaluate condition (a, b). Although insula activation specifically correlates with a decrease in subjects' buying prices (Δ-WTP) in reference to the evaluate condition but not change in the selling condition (c). To identify brain areas specifically associated with the endowment effect, regions in which activity correlated with increasing selling and decreasing buying prices in the computer condition were subtracted out in this comparison (see Materials and Methods). a shows BOLD activation in anterior right striatum [x = 26, y = 14, z = 0] (Z score = 3.56) in a coronal and sagittal plane. b shows activity in the posterior left striatum [x = −28, y = −6, z = −4] (Z score = 2.94) in a coronal and sagittal plane. c shows activity in left insula [x = −54, y = 20, z = −2] (on the left) and in right insula [x = 50, y = 12, z = −6] (on the right) in a coronal plane. On the right of each panel (a–c) is shown the plot of the parameter estimates for each You condition (i.e., WTP and WTA) subtracted for the baseline conditions (i.e., forced computer conditions; see Materials and Methods for more details). Note that no error bars are displayed because reported statistical comparisons reflect within-subject effects. Effects are shown at p < 0.005 for display purposes.