The Brain Network for Haptic Object Recogniton

Humans can haptically identify common three-dimensional objects surprisingly well. What are the neural mechanisms underlying this ability? Previous neuroimaging studies have shown that haptic object recognition involves a distributed network of brain regions beyond the conventional somatosensory cortices. However, the relative contributions of these regions to haptic object recognition are not well understood. In this chapter, I discuss three key hypotheses concerning the brain network underlying haptic object processing and its interaction with visual object processing. The first is that the occipito-temporal cortex, which has been considered to be part of the conventional visual cortex, plays a critical role in the haptic identification of common objects. The second is that distinct brain regions are involved in the haptic processing of two types of feature used for object identification: macro-geometric (e.g., shape) and material (e.g., roughness) properties. The third is that different brain regions are also involved in the visuo-haptic interaction of macro-geometric and material properties. Finally, I discuss some issues that remain to be addressed in future studies.