Figure 2.

Experimental apparatus and configurations. A, Left, Wooden cube apparatus with elevated start box leading to front vertical wall. Middle, Configuration of apparatus used for testing a 45° outside vertical corner. Right, Configuration of apparatus used for traversal of an inside vertical corner. Route follows numerical order from 1 to 5. B, Different routes for one-wall, two-wall, and three-wall paradigms. The three-wall paradigm involved travel along four walls between the start box and the cube top—first from the front wall to one of the adjacent walls, followed by a return to the front wall, and then travel to the other adjacent wall. For clarity, start box is shown positioned on the floor, but in fact it was elevated as shown in A. C, Left, Coordinate system used for each of the surfaces for all sessions except for the session involving an inside vertical corner. Right, Coordinate systems used for the session involving an inside vertical corner.