UBC Theses and Dissertations

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UBC Theses and Dissertations

An exploratory study of the stopper device in modern slot machines Chu, Stephanie Wing-Man


The stopper device is a common feature on modern slot machines that enables players to brake the spinning reels manually, but with no actual influence on the likelihood of winning. This study explored two potential mechanisms for why players might use the stopper device: (1) by increasing an ‘illusion of control’, and (2) by increasing the speed of game play. Thirty student participants from UBC and 32 community participants from the Greater Vancouver area participated in the study. Unlike previous research on the effects of the stopper device (e.g. Ladouceur & Sévigny, 2005), participants played a real slot machine (instead of pre-programmed slot machine simulator) equipped with a stopper, and were able to decide when and how often they used the stopper. Physiological arousal (heart rate and skin conductance) were monitored during game play. Participants completed the Gamblers’ Beliefs Questionnaire as a measure of trait susceptibility to the illusion of control, and after the game session, participants provided state ratings of the effectiveness of the stopper (i.e. illusory control) and their game play experience. Contrary to predictions, no significant relationships were observed (in either sample) between stopper use and the illusion of control. Stopper use was associated with faster speed of play, as measured by the spin initiation latencies. In addition, wins on trials where the stopper was used tended to increase ongoing stopper use, consistent with reinforcement via operant conditioning. Wins elicited a significant increase in heart rate, but no connection was found between stopper use and physiological arousal. Overall, the pattern of data indicated that stopper use may be better explained in associative learning (reinforcement and speed of play) than by higher-level cognitive appraisals (illusion of control). By increasing speed of play, stopper device may increase gambling losses and harms, and policy implications for the regulation of the stopper feature are considered.

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