The difference of these two curves (Figure 1E, black) is a very sensitive assay for discrimination performance; the fitted maximum of this curve (Figure 1E, blue) is referred to as the “discrimination index” in the remainder of the paper and is again strongly improved for GluR-BΔECS:FB mice, compared with controls (Figure 1F; group effect: F(1,10) = 11.7, p < 0.01).