Vision and touch: independent or integrated systems for the perception of texture?

In the following review, we discuss the evidence for the role of vision and touch in the perception of texture with the particular aim of evaluating whether these systems contribute information to texture perception in either an independent or integrated manner. Although texture is perceived by both vision and touch, several behavioural and neuroimaging studies have suggested that texture information is processed in qualitatively different ways, such that the type of information encoded and the manner in which it is encoded differs across these sensory systems. Furthermore, vision and touch perceive different aspects of texture information with vision the more appropriate modality for discriminating texture boundaries and touch the more appropriate modality for discriminating stimulus roughness and compliance. Differences also exist in the neural structures and functions which underlie these systems, further suggesting independence of these modalities in the perception of texture. Accordingly, recent evidence suggests that behavioural tasks involving texture perception do not benefit from integration across the senses, suggesting that qualitatively different information is represented across vision and touch which cannot be combined to enhance perceptual performance. Research using more familiar objects, however, does suggest a role for sensory integration on texture perception, although these effects may be due to more cognitive influences rather than basic sensory encoding. In sum, we suggest that unlike shape perception, vision and touch contribute information to the perception of texture in an independent but complementary manner.