Abstract
Tool use is a defining feature of the human species. Tool-in-hand, humans can manipulate their environment in novel ways as well as process the sensory information arising during mechanical contact. This fact has led cognitive neuroscience researchers over the last few decades to explore how tool-based body augmentation impacts the behavior and neural processing of their users. In this chapter, we explore the findings of this research and draw some tentative conclusions about its implications for the sensorimotor system. We first survey research, conducted over the past decade, that has found that using a tool modulates body representations underlying action and somatosensory perception. This research includes both behavioral and neural approaches. We then focus on the sensory and functional underpinnings driving the tool-induced plasticity to body representations. Finally, we describe a novel means to evaluate the incorporation of tools into the sensorimotor system: The ability of humans to sense the locations of external objects with a tool. We will discuss how this research has already gained powerful insight into the relationship between tools and the body, as well as challenging our conception of the boundaries of the somatosensory system.
