Environmental Learning without Vision: Effects of Cognitive Load on Interface Design

Blindfolded participants were guided along routes from two display modes: spatial language ("left," "right," or "straight") or spatialized audio (where the perceived sound location indicates the target direction). Half of the route guidance trials were run concurrently with a secondary vibrotactile N-back task. To assess cognitive map development, subjects performed a homing task from the route's terminus. As spatialized audio displays are processed perceptually, we hypothesized they would be less affected by increased cognitive load than language displays, which require cognitive mediation. In corroboration, results showed the secondary task had no effect on cognitive map performance for guidance by spatialized audio but led to significantly worse homing errors for guidance by spatial language. Spatialized audio was also reliably faster and more accurate than language for traversing the route. These results have important implications for the design of future navigation and guidance systems for visually impaired persons.