Gesture During Mental Rotation

Gesture During Mental Rotation Autumn B. Hostetter (Autumn.Hostetter@kzoo.edu) Department of Psychology, 1200 Academy Street Kalamazoo, MI 49006 USA Martha W. Alibali (mwalibali@wisc.edu) Department of Psychology, 1202 W. Johnson Street Madison, WI 53706 USA Anne E. Bartholomew (aebartholome@wisc.edu) Department of Psychology, 1202 W. Johnson Street Madison, WI 53706 USA Abstract Speakers gesture at high rates when explaining their solutions to spatial problems. The present work investigates one possible explanation for why speakers gesture so frequently during spatial problem solving, namely, that when speakers imagine the problem components in motion, they are particularly likely to gesture. We compared speakers’ gesture rates as they actively solved a mental rotation problem and as they described the end state of the problem. Speakers gestured at a higher rate in the rotation condition. Thus, it appears that thoughts about the problem pieces in motion in the rotation condition do lead to increased gesture rates. Keywords: gesture; spatial problem solving; mental imagery; simulation Introduction Speakers often gesture when they describe their solutions to spatial problems (e.g., Chu & Kita, 2008, 2011; Goldin- Meadow & Beilock, 2010). As one example, Hegarty, Mayer, Kriz, and Keehner (2005) found that approximately 90% of participants spontaneously gestured when asked to describe their solutions to mental animation problems. What is it about describing problem solutions that elicits gesture so reliably? The present work addresses this question. One possible explanation is that gestures are simply a natural and effective way of expressing spatial information (e.g., Alibali, 2005; Emmorey & Casey, 2001; Kendon, 2004). The “expressive possibilities” of gesture (Kendon, 2004) are well suited for expressing information about actions and spatial relationships, so such information is very likely to be expressed in gestures. Another possible explanation is that participants reactivate the actions involved in solving the problems during description, and that some aspects of these reactivations are expressed as gestures. Indeed, there is some evidence that the particular form of gestures that occur during problem descriptions appears to be related to the form of the action involved in solving the problem. For instance, Cook and Tanenhaus (2009) found that the specific form of the gestures produced by speakers as they described their solutions to the Tower of Hanoi problem was related to whether they had solved the problem on a computer or by physically manipulating discs. When speakers had solved the problem with physical discs, they were much more likely to produce gestures that arced up and over (as though lifting the pieces) than when they had solved the problem on the computer. The co-occurrence between the form of an action used in a particular problem and the form of the gesture used in descriptions of the problem is predicted by a recent account of gesture called the Gesture as Simulated Action (GSA) framework (Hostetter & Alibali, 2008). According to this view, gestures arise as outward manifestations of the simulations that occur during language production. Simulations are neural reenactments of perceptual and motor states that occur during interaction and experience with the world (see Barsalou, 2008; 2009). When speakers think about and describe experiences they have had, simulations of the experience cause cortical activation in the same motor and perceptual areas of the brain that were involved during the initial experience. The GSA framework claims that this cortical activation supports the production of gestures that partially or fully reenact the actions produced in the initial experience. One implication of the GSA framework is that simulations that involve motor activation should be especially likely to result in gestures. The GSA framework distinguishes between simulations of motor imagery, which involve imagination of the body or percepts in motion, and simulations of visual imagery, which involve imagination of static percepts. Because motor imagery is particularly likely to rely on activation in motor areas of the brain (Richter et al., 2000), motor imagery should be more likely to result in gesture than visual imagery, other things being equal. Indeed, in the first experimental test of the GSA framework, Hostetter and Alibali (2010) demonstrated that speakers gesture at a higher rate when they have specific, relevant motor experience with the information they are describing than when they do not. From the perspective of the GSA framework, then, the prevalence of gestures with descriptions of spatial problems,