Fig. 1.

Experiment 2: reorientation in the real-cliff and artificial-cliff conditions. The schematics show the experimental setup in the real-cliff (a) and artificial-cliff (b) conditions. In the real-cliff condition, animals were forced to navigate a rectangular shape, whereas in the artificial cliff, a rectangular texture was placed on a circular platform that did not limit the traversable space to the task-relevant area (i.e., the rectangle containing the four cups). The task consisted in finding a reward hidden in one of the four cups at the edges of the rectangular shape that enclosed the cup locations. In the schematics, green indicates the correct rewarded location, black indicates the location nearest to the reward along the same short wall as the reward location, red indicates the geometrically opposite corner from the reward location, and gray indicates the location not associated with the correct geometric axis or the short wall near the reward. The percentage of digs in the four different cup locations is shown for the real-cliff (c) and artificial-cliff (d) conditions on Days 3 and 4; means are shown for sighted mice in the upper row and blind mice in the lower row. Results are shown separately for each cup location, using the color codes shown in (a) and (b). Digging preference (proportion of first digs in the geometrically correct axis relative to the total number of digs) is shown for sighted and blind mice in the real-cliff (e) and artificial-cliff (f) conditions on Days 3 and 4. Bars show means (error bars indicate standard errors of the mean), and dots represent individual data. The asterisk indicates a significant difference between means for sighted and blind mice (α = .05). Real-cliff condition: sighted mice: n = 10, blind mice: n = 9; artificial-cliff condition: sighted mice: n = 12, blind mice: n = 11.