Spontaneous alternation behavior in humans

Redirected walking refers to a number of techniques that enable users to explore a virtual environment larger than the physical space by real walking. The efficiency of these techniques has been shown to improve when predictions about the user's future trajectory are incorporated. Predictions can be made not only based on the knowledge about the environment but also on how humans behave in it. In a maze-like environment, it is known that most animal species show a strong preference to alternate their turning direction. This is called spontaneous alternation behavior (SAB). Although such behavior has also been observed in humans during maze tracing tasks, little is known whether they also exhibit this behavior during real walking, and if they do, what their alternation rate is. In the experiment described in this paper, 60 right-handed subjects were invited to walk freely through a virtual maze consisting of a primary 90° forced turn followed by three consecutive T-junctions. Results show that, on average, humans exhibited an alternation rate of 72%. When looking only at the junction after the forced turn, subjects alternated with 76%. After two consecutive turns of the same direction subjects alternated with 93%. The alternation rates obtained not only clearly confirm the existence of SAB in humans but also could be used to improve the accuracy of existing prediction models in human walking.