Blind people editing virtual tactile maps - a manipulation task

Frequently in rehabilitation, visually impaired subjects are passive agents of exercises with fixed environmental constraints. 

In fact a printed tactile map, i.e. a particular picture with a specific spatial arrangement, cannot be edited.

This study aims at understanding if visually impaired people can autonomously build tactile maps which are completely virtual.

Specifically, we investigated if they could exploit mental imagery to interact with virtual content and actively manipulate it by means of a haptic device that allows to perceive tactile virtual objects.

The experiment consisted in a bi-manual tactile task, in which one hand explored some simple virtual objects and the other hand acted on a keyboard to change their position in real-time. The goal was to merge basic into more complex objects.

The experiment spanned across different resolutions of the tactile information. We measured task accuracy, efficiency, usability and execution time.

The participants were 90.5% accurate in solving the puzzle.

Importantly, accuracy was linearly predicted by efficiency, as measured by the number of moves to solve the task. 

Subjective parameters linked to usability and spatial resolutions did not predict accuracy; gender modulated the execution time, with man faster than woman in solving the puzzle.

Overall, we show that building purely virtual tactile objects is possible in absence of vision and that the process is measurable and achievable in partial autonomy. 

Introducing virtual tactile graphics in rehabilitation protocols could facilitate the stimulation of mental imagery in blind persons, also because behavioral variables, not available otherwise, could be used to automatically measure and tailor protocols to specific user needs. In perspective, our experimental setup can inspire remote rehabilitation scenarios.