On the Potential of Epistemic Actions for Self-Cueing: Multiple Orientations Can Prime 2D Shape Recognition and Use

On the Potential of Epistemic Actions for Self-Cueing: Multiple Orientations Can Prime 2D Shape Recognition and Use Paul P. Maglio (pmaglio@almaden.ibm.com) IBM Almaden Research Center San Jose, California Michael J. Wenger (mwenger1@nd.edu) Department of Psychology University of Notre Dame Abstract Epistemic actions are physical actions people take more to simplify their internal problem-solving pro- cesses than to bring themselves closer to an exter- nal goal. Consider how when playing the video game Tetris, experts routinely rotate falling two- dimensional shapes more than is necessary to place the shapes. One reason for such apparently unnec- essary actions is that they actually help the player make placement decisions. Such actions might fa- cilitate placement decisions if additional previews of the shape a↵orded by rotating it provide infor- mation about the board, particularly when there is no direct perceptual match between the shape and the board at the time of decision. The study pre- sented here tests the hypothesis that several distinct previews of a two-dimensional shape can improve a person’s ability to recognize and use that shape when it is not correctly oriented at the time of de- cision. Results show that indeed task performance and recognition are faster with two di↵erent orien- tations than with only one. Thus, it is possible that Tetris players rotate two-dimensional Tetris shapes manually to see them in more than one orientation, as this can lead to faster decisions. Introduction People playing the video game Tetris often take ac- tions that are not strictly necessary but that serve to simplify or speed up internal cognitive or percep- tual operations (Kirsh & Maglio, 1994; Maglio & Kirsh, 1996). Playing Tetris involves maneuvering falling two-dimensional shapes into specific arrange- ments on the computer screen (see Figure 1). Even as players become faster with practice, they tend to over-rotate falling shapes, leading to backtrack- ing as these over-rotations are corrected. To make sense of such backtracking, Kirsh and Maglio (1994) argued that sometimes physical rotation can serve the same purpose as mental rotation, e↵ectively of- floading mental computation onto the physical world (see also Clark, 1997; Kirsh, 1995; Maglio, Matlock, Raphaely, Chernicky & Kirsh, 1999). Such physical actions—taken to simplify internal cognitive compu- tation rather than to move closer to the external goal state—are called epistemic actions. Because shape identification can be facilitated when primed with orientations di↵erent from the target orientation (Cooper, Schacter, Ballesteros & Moore, 1992; Srinivas, 1995), and because numeros- ity judgments can be facilitated even when test stim- uli are not presented at the same orientation as the originally learned patterns (Lassaline & Logan, 1993), memory for a target pattern might not re- quire the retrieval cue be specifically oriented. Thus, the epistemic function of physical rotation in Tetris might be far more complex than is suggested by the simple idea that physical rotation can substitute for mental rotation, for instance, serving the function of cueing retrieval (Kirsh & Maglio, 1994). Because physically rotating a Tetris shape (which we call a zoid) provides the player two views of it (i.e., in each of two orientations), it is possible that seeing two di↵erent views makes retrieval of relevant informa- tion easier than does seeing just one. In fact, we found previously that when participants in a Tetris- like task are presented with two views of a zoid, the time taken to decide whether it fits a particular board is faster than when participants are presented with only a single view, but this does not depend on the orientation of the previews relative to one another (Maglio & Wenger, 2000). There are at least three potential functions of ro- tation for self-cueing in Tetris. First, seeing the falling zoid in several di↵erent orientations may pro- vide helpful information about the board, particu- larly when there is no direct perceptual match be- tween zoid and board at decision time. That is, if the orientation of the zoid floating above the board does not match the orientation in which the zoid ac- tually fits the board when the player must decide to place it, then having previously seen the zoid in the matching orientation might help the process of men- tally matching zoid and board. Such an e↵ect might be the result of having recently seen the zoid in its fitting orientation, basing the decision as to whether the zoid matches the board on memory rather than on mental rotation. Let us call this potential epis-