Non-visual identification of walking grounds

Abstract

We investigated the role of haptic, proprioceptive and auditory information in the non-visual identification of walking grounds. We selected four solid materials (e.g., marble) and four aggregate materials (e.g., fine gravel). Five observers identified the materials in each of four experimental conditions: multisensory, haptic, proprioceptive, and auditory. In the auditory condition, they were presented with walking sounds they produced. In the other conditions, observers walked blindfolded on the materials. In the haptic and proprioceptive conditions auditory information was masked. In the proprioceptive condition haptic information was masked. No masking took place in the multisensory condition. In all conditions, solids and aggregates were seldom confused, and aggregates were better identified than solids. Chance identification performance was observed only for solids in the presence of simultaneous haptic and auditory masking, suggesting a secondary role of proprioceptive information. In the proprioceptive condition, identification of aggregates was better than chance, suggesting a significant role of proprioception. Identification of aggregates was at its best in the haptic condition, and not in the multisensory condition, suggesting either an inconsistency of information between auditory and non-auditory channels, or conflicting cognitive strategies for the exploitation of these sources of information in multisensory contexts.