The influence of the encoding modality on spatial navigation for sighted and late-blind people

People usually rely on sight to encode spatial information, becoming aware of other sensory cues when deprived of vision. In the absence of vision, it has been demonstrated that physical movements and spatial descriptions can effectively provide the spatial information that is necessary for the construction of an adequate spatial mental model. However, no study has previously compared the influence of these encoding modalities on complex movements such as human spatial navigation within real room-size environments. Thus, we investigated whether the encoding of a spatial layout through verbal cues - that is, spatial description - and motor cues - that is, physical exploration of the environment - differently affect spatial navigation within a real room-size environment, by testing blindfolded sighted (Experiment 1) and late-blind (Experiment 2) participants. Our results reveal that encoding the environment through physical movement is more effective than through verbal descriptions in supporting active navigation. Thus, our findings are in line with the studies claiming that the physical exploration of an environment enhances the development of a global spatial representation and improves spatial updating. From an applied perspective, the present results suggest that it might be possible to improve the experience for visually impaired people within a new environment by allowing them to explore it.