Gestures are often considered to be valid evidence of the embodiment of language and cognition. Since people use their bodies (i.e., gestures) to express knowledge, it is argued, the knowledge itself must be deeply tied to the body (Alibali & Nathan, 2007; Gallagher, 2005; Gibbs, 2006; Hostetter & Alibali, 2004; McNeill, 2005; Nuñez, 2005) . This claim may hold some truth, but to date, there have been no explicit proposals about how embodied knowledge comes to be reflected in speech-accompanying gestures. The goal of this article is to explore how gestures may arise from embodied thinking; we will approach this goal by integrating research about perception, action, cognition, language, mental imagery, and gesture production. A variety of hand and body movements can be considered to be gestures, and much previous research has sought to describe these different types of gestures (e.g., Efron, 1972; Kendon, 2004; McNeill, 1992) . In this article, we limit our discussion to representational gestures-that is, movements that represent the content of speech by pointing to a referent in the physical environment (deictic gestures), depicting a referent with the motion or shape of the hands (iconic gestures), or depicting a concrete referent or indicating a spatial location for an abstract idea (metaphoric gestures). We use the term gestures to refer specifically to representational gestures. Other types of gestures, including beat gestures (movements that emphasize the prosody or structure of speech without conveying semantic information) and interactive gestures (movements used to manage turn taking and other aspects of an interaction between multiple speakers), fall outside the scope of this article. Our aim is to describe a mechanism that may possibly give rise to gestures. We do not seek to address the issue of the functions of gestures (e.g., in communication, in speech production). Although we review some ideas about the functions of gestures, we do not take a strong stance here regarding gesture function. The goal of our framework is to explain what gestures are, rather than what they do. The article proceeds in seven sections. In the first section, we review ideas about links between perception and action and how these links are important in memory and cognition. In the second section, we review evidence that language processing is tied to the body. In the third section, we review evidence that mental imagery is also an embodied process. In the fourth section, we review evidence on the relationship between gesture production and mental imagery, and in the fifth, we propose a theoretical framework that explains how gestures may arise from the activation of perception and action. In the sixth section, we compare our framework with other models of gesture production. Finally, in the seventh section, we articulate predictions that derive from the framework. Many theorists have proposed that perception is for action (J. J. Gibson, 1979; Sperry, 1952) ; that is, the ability to perceive evolved from a need to interact with the world. Perception enables us to know the affordances of objects in our environment and thus enables us to guide our actions in a goal-directed way (see, e.g., Adolph, 1997) . Without this knowledge, it would be virtually impossible to know which object is best for hiding behind, sitting on, climbing up, or any number of other potential actions that were presumably important for survival in the ancestral environment. It is thus difficult to imagine perception as having evolved as anything but an "ongoing process of finding appropriate responses to the environment" (Borghi, 2005, p. 9). Perception is adaptive because it enables quick and effective reactions to the stimuli we encounter. If perception indeed evolved primarily to facilitate action, one might predict that perceptions should elicit appropriate actions quite automatically. Indeed, there is accumulating evidence that action plans are involuntary consequences of our perceptions. Tucker and Ellis (1998) found that responses that indicated whether a visually perceived object Copyright 2008 Psychonomic Society, Inc. Spontaneous gestures that accompany speech are related to both verbal and spatial processes. We argue that gestures emerge from perceptual and motor simulations that underlie embodied language and mental imagery. We first review current thinking about embodied cognition, embodied language, and embodied mental imagery. We then provide evidence that gestures stem from spatial representations and mental images. We then propose the gestures-as-simulated-action framework to explain how gestures might arise from an embodied cognitive system. Finally, we compare this framework with other current models of gesture production, and we briefly outline predictions that derive from the framework.
The system addresses the representational gestures REF , e.g., movements pointing to a referent in the physical environment (deictic gestures) or gestures describing a concept with the movement or shape of the hands (iconic gestures).
Visible embodiment: Gestures as simulated action
Psychonomic bulletin & review
Psychonomic bulletin & review
Psychology Medicine