The literature often suggests that proprioceptive and especially vestibular cues are required for navigation and spatial orientation tasks involving rotations of the observer. To test this notion, we conducted a set of experiments in virtual environments in which only visual cues were provided. Participants had to execute turns, reproduce distances, or perform triangle completion tasks. Most experiments were performed in a simulated 3D eld of blobs, thus restricting navigation strategies to path integration based on optic ow. For our experimental set-up (half-cylindrical 180 deg. projection screen), optic ow information alone proved to be suf cient for untrained participants to perform turns and reproduce distances with negligible systematic errors, irrespective of movement velocity. Path integration by optic ow was suf cient for homing by triangle completion, but homing distances were biased towards the mean response. Additional landmarks that were only temporarily available did not ...
Bernhard E. Riecke, Henricus A. H. C. van Veen, He