Fig 2. The virtual environments.

Screen captures of the hallway environment (A and B) and the starfield environment (C and D). A and C are what the scenes looked like before movement while the target (vertical red line) was visible and the walls were invisible, B and D are what the scenes looked like once the participant had clicked the left mouse button and the optic flow started to simulate motion down the hallway. The hallway environment was used in Experiments 1, 2, and 3, the starfield environment was used only in Experiment 3.