Reading with the Tongue: Individual Differences Affect the Perception of Ambiguous Stimuli with the BrainPort

There is an increasing interest in non-visual interfaces for HCI to take advantage of the information processing capability of the other sensory modalities. The BrainPort is a vision-to-tactile sensory substitution device that conveys information through electro-stimulation on the tongue. As the tongue is a horizontal surface, it makes for an interesting platform to study the brain's representation of space. But which way is up on the tongue? We provided participants with perceptually ambiguous stimuli and measured how often different perspectives were adopted; furthermore, whether camera orientation and gender had an effect. Additionally, we examined whether personality (trait extraversion and openness) could predict the perspective taken. We found that self-centered perspectives were predominantly adopted, and that trait openness may predict perspective. This research demonstrates how individual differences can affect the usability of sensory substitution devices, and highlights the need for flexible and customisable interfaces.