Upsides and Downsides of Gesturing in Problem Solving

Upsides and Downsides of Gesturing in Problem Solving Patrick J. Cushen (pcushe2@uic.edu) Department of Psychology, 1007 W. Harrison Street MC 285 Chicago, IL 60607 USA Jennifer Wiley (jwiley@uic.edu) Department of Psychology, 1007 W. Harrison Street MC 285 Chicago, IL 60607 USA Abstract The ToH task is considered complex because it requires the use of multiple processes. First, it requires the creation and maintenance of a problem representation. The representation includes not only the physical objects of the problem (the disks and pegs), but also the task rules, which determine the legality of moves. Errors at the representation level may lead to repeated violations of the rules or memory mistakes related to the positions of disks. Second, the task requires planning. That is, in order to solve efficiently, subjects are required to think ahead, establishing both distant goals (such as the moving of a particular disk to its final location) and immediate subgoals (such as making other moves to open up the opportunity to complete the overarching goal; Anderson, Kushmerick, & Lebiere, 1993). Errors in planning may lead solvers into dead-end movement sequences. Third, efficient solvers need to be able to represent and monitor their progress. It is necessary to keep track of the various objects and subgoals as well as progress through a mental representation of the solution sequence. In addition, solvers must be able to detect errors in planning and correct their mistakes. Errors in monitoring can result in the solver losing track of his or her place, or perseverating on poor moves or movement sequences. One could imagine that, in complex problem solving (with numerous cognitive processes operating at the same time), capacity limitations may influence problem-solving performance. Working memory capacity (WMC) is a construct that can generally be defined as the ability to retain information in memory while concurrently processing other information (Baddeley, 2002). Differences in WMC have more recently been conceptualized as differences in an attentional-control ability or executive function (Engle, 2002). That is, the ability of a person to perform well on a working memory span task such as reading span or operation span is related to their ability to control or direct their attention (for example, to focus on goal-related stimuli in the face of interference; Conway et al., 2005). WMC is an important individual difference in cognitive psychology that correlates with numerous measures of cognitive ability (Conway, et al., 2005; Engle, 2002). Researchers have suggested that effective use of working memory is integral to successful problem solving, as the inability to adequately maintain different pieces of information in memory is a significant impairment to problem solving performance (i.e. Kotovsky, Hayes, & Simon, 1985). Additionally, numerous computer models of Research has shown that gesturing can serve to both clarify our thinking and improve our working memory. Working memory capacity (WMC) is widely considered to be a contributing factor in a number of higher order cognitions, including problem solving. The current study investigated the influence of individual differences in WMC, the number of moves required for solution, and the ability to gesture during solution of the Tower of Hanoi. The results show a complex relationship between WMC, problem size and the ability to gesture, and that there are both upsides and downsides to gesturing while problem solving. Keywords: Problem Solving, Working Memory Capacity, Gesture, Tower of Hanoi. Introduction Research has shown that gesturing can serve to both clarify our thinking and improve our working memory (Wagner, Nusbaum, & Goldin-Meadow, 2004). In the present research, we sought to explore the role of gesture in first time problem solving of the Tower of Hanoi (ToH). The ToH task (Simon, 1975) has been used in the cognitive literature as a benchmark cognitive test. It has been used to test a number of higher cognitive abilities, including skill acquisition and transfer (Reber & Kotovsky, 1997), as well to observe developmental changes in cognitive ability and to assess mental deficits in patient populations. ToH is a complex, yet well-structured problem. Though difficult, its solution space is well-defined. In the classic problem, participants are given three pegs with three differently-sized disks on the first peg. The smallest disk is on top and the largest on the bottom. The goal is to move all disks to the third peg, one disk at a time. In addition, participants are given the constraints that larger disks cannot be placed on smaller disks and that only a top disk can be moved. Even this basic presentation requires at least seven movements to reach the solution. Figure 1. The 3-Disk Tower of Hanoi.