This chapter discusses the contributions of functional imaging to our understanding of how action and tool concepts are represented and processed in the human brain. Section 7.1 introduces cognitive models of semantic organization. Section 7.2 provides a brief overview of functional imaging approaches to identify brain regions that have specialized for processing action and tool representations. Section 7.3 discusses the relationship between the visuomotor system and semantic processing of actions. Section 7.4 investigates the effects of action type and visual experience on action-selective responses. Section 7.5 characterizes the neural systems engaged in tool processing and how they are modulated by task and stimulus modality. Section 7.6 delineates future directions that may enable us to characterize the neural mechanisms that mediate tool and action-selective brain responses.

Cognitive models of semantic organization

Since the seminal work of Warrington and Shallice (1984), double dissociations of semantic deficits have been established between tools and animals (for review, see Gainotti et al., 1995; Warrington & Shallice, 1984; Capitani et al., 2003; Gainotti & Silveri, 1996; Farah et al., 1996; Hillis & Caramazza, 1991; Sacchett & Humphreys, 1992; Warrington & McCarthy, 1987). These double dissociations persist even when attempts are made to control general processing differences due to confounding variables such as familiarity, visual complexity, or word frequency (Farah et al., 1996; Sartori et al., 1993). They appear, therefore, to reflect some sort of semantic organization at the neuronal level.

Many cognitive models have been offered to explain these category-specific deficits.