Twists and Oliver Twists in Mental Rotation: Complementary Actions as Orphan Processes

Twists and Oliver Twists in Mental Rotation: Complementary Actions as Orphan Processes Sanjay Chandrasekharan (sanjayen@gmail.com) Dilip Athreya (athreyadilip@yahoo.com) Narayanan Srinivasan (ammuns@yahoo.com) Centre for Behavioural and Cognitive Sciences University of Allahabad, Allahabad 211002, India Abstract A growing body of work shows that compatible actions executed in parallel with cognitive tasks contribute beneficially to cognition, compared to incompatible actions. We investigate how such complementary actions are generated. Two models from imitation research, Associated Sequence Learning (ASL) and Active Intermodal Matching (AIM), were extended to develop models of complementary action generation. ASL postulates a general generation process based on learning, whereas AIM postulates a specialist process. Using a mental rotation task where participants tended to spontaneously generate parallel actions, we conducted two experiments to test the predictions of the extended models. Surprisingly, the results show that when compared to no-actions, complementary actions do not improve accuracy. The two experiments do not provide clear validation for either model of generation, but there is more support for the generalist model than the specialist one. We propose a revision to the generalist model based on this trend. Keywords: Complementary Actions, Epistemic Actions, Imitation, Mental Rotation, Situated Cognition Introduction Actions compatible with cognitive tasks such as mental rotation and counting have been shown to contribute beneficially to cognition (Kirsh & Maglio, 1994; Kirsh, 1995; Kosslyn, 1994; Wexler, Kosslyn & Berthoz, 1998; Goldin-Meadow & Wagner, 2005). Recent work also argues that such actions may play a beneficial role in perception (Wexler & van Boxtel, 2005; Noe, 2004). What is the mechanism underlying the generation of such complementary actions? This is the question we address in this paper. The paper is organized as follows: Section 1 reviews some of the evidence that supports the beneficial role of action in cognition. Section 2 examines two possible models of the mechanisms underlying such actions, and their predictions. Section 3 presents our experiments and results. Section 4 discusses how the results relate to the models. We conclude with future work. Action Supporting Cognition Most studies examining the link between action and cognition report that actions compatible with cognitive tasks play a beneficial role in cognition. The most influential study in this area is Kirsh and Maglio (1994), which showed that even in a fast-paced task environment like the Tetris video game, players use actions to lower computational load. Tetris involves maneuvering falling shapes (zoids) into specific arrangements on the screen. Players execute actions on the falling zoids, to expose information early, to prime themselves to recognize zoids faster, and to perform external checks and verifications to reduce the uncertainty of judgments. The point of taking such actions is “is not for the effect they have on the environment as much as for the effect they have on the agent” (Kirsh & Maglio, 1994). The authors term such actions ‘epistemic actions’, which are defined as “physical actions whose primary function is to improve cognition by: 1) reducing the memory involved in mental computation; 2) reducing the number of steps involved in mental computation; 3) reducing the probability of error in mental computation” (Kirsh & Maglio, 1994). The primary computations involved in Tetris are mental rotation of the zoids and matching of zoids to available slots. The participants physically rotate the zoids to significantly lower the amount of mental rotation required to judge the ‘fit’ of a zoid to available slots. This involves a visual comparison between slots and the physically rotated zoids. However, a visual comparison is not required for actions to aid in mental rotation. Wexler et al (1998) show that unseen motor rotation in the Cooper-Shepard mental rotation task (Cooper & Shepard, 1973) leads to faster reaction times and fewer errors when the motor rotation is compatible with the mental rotation than when they are incompatible. They also report that in some cases motor rotation made complex mental rotations easier. Also, speeding up the motor rotation speeded up the mental rotation, while slowing the motor action slowed down the mental one. Similar effects have been shown to exist in children (Frick, Daum, Walser & Mast, 2005). Manipulating virtual objects have also been reported to improve subsequent mental rotation and recognition of such objects (Wexler & van Boxtel, 2005). Besides the above direct evidence, Kosslyn (1994) reports extensive indirect evidence for the role of action in mental rotation, including a study that showed participants need more time to perform mental rotations that are physically awkward, and another one where incompatible movements disrupted memory. Kosslyn (1994) also refers to a brain- damaged patient who consistently reached up to the screen