The Role of Free Spins in Slot-machine Gambling

<p>Slot-machine gambling is disproportionately associated with problem gambling. It is therefore important to develop an understanding of how the programming and features of slot machines influence gambling. The current research programme investigated a major feature of many slot machines which has so far been neglected by experimental research – the free-spins bonus feature. The first major focus of this research was a series of experiments that investigated whether participants prefer to play a slot-machine simulation with a free-spins bonus feature. In each experiment participants gambled on two simulations, one with a free-spins feature and a similar machine without free spins. Following this, participants could switch between the same simulations and the number of spins they made on each simulation was measured. Participants preferred the free-spins simulation, but only when the free-spins feature incorporated an increased rate of wins, music, animations, and graphics advertising the presence of the free-spins feature. In the final experiment investigating preference, we investigated whether responding was influenced by whether participants gambled with hypothetical money, or credit that could be exchanged for tangible rewards. Participants preferred the complex free-spins simulation similarly regardless of what they were gambling with, but selected larger bet amounts and gambled for longer when gambling with hypothetical money. The second major focus of this research programme was an investigation of whether free-spins features cause increased gambling persistence – a hallmark of disordered gambling. We developed a new persistence-measuring task which was adapted from research investigating Behavioural Momentum Theory. Participants gambled on two simulations in a multiple schedule design. An initial baseline phase consisted of four alternations of each component, one of which had the complex free-spins feature demonstrated to increase preference in the earlier experiments. Baseline phases then alternated with disruption phases where video-clips were embedded into the top right corner of the simulations. The rate at which participants gambled during baseline was compared to the rate at which they gambled when the videos were present, with bigger relative decreases in response rate during the disruption phases indicating less persistence. The free-spins feature did not cause participants to gamble more persistently. Further experiments also assessed whether different frequencies of wins caused participants to gamble more persistently, and results indicated that they did not. The findings of this research programme have implications for Behavioural Momentum Theory, suggesting that comparing response rate during disruption to response rate during baseline is not highly sensitive to small differences in reinforcement schedules. The findings are also relevant for slot-machine legislation, providing an indication that limiting or removing free-spins features may reduce player enjoyment without reducing persistent gambling. Furthermore, the task developed in the persistence investigation provides a useful tool which can be used to investigate how other features of slot machines influence persistence. Future research could, for example, investigate how free-spins features interact with other slot-machine features to influence gambling behaviour.</p>

The Role of Free Spins in Slot-machine Gambling

<p>Slot-machine gambling is disproportionately associated with problem gambling. It is therefore important to develop an understanding of how the programming and features of slot machines influence gambling. The current research programme investigated a major feature of many slot machines which has so far been neglected by experimental research – the free-spins bonus feature. The first major focus of this research was a series of experiments that investigated whether participants prefer to play a slot-machine simulation with a free-spins bonus feature. In each experiment participants gambled on two simulations, one with a free-spins feature and a similar machine without free spins. Following this, participants could switch between the same simulations and the number of spins they made on each simulation was measured. Participants preferred the free-spins simulation, but only when the free-spins feature incorporated an increased rate of wins, music, animations, and graphics advertising the presence of the free-spins feature. In the final experiment investigating preference, we investigated whether responding was influenced by whether participants gambled with hypothetical money, or credit that could be exchanged for tangible rewards. Participants preferred the complex free-spins simulation similarly regardless of what they were gambling with, but selected larger bet amounts and gambled for longer when gambling with hypothetical money. The second major focus of this research programme was an investigation of whether free-spins features cause increased gambling persistence – a hallmark of disordered gambling. We developed a new persistence-measuring task which was adapted from research investigating Behavioural Momentum Theory. Participants gambled on two simulations in a multiple schedule design. An initial baseline phase consisted of four alternations of each component, one of which had the complex free-spins feature demonstrated to increase preference in the earlier experiments. Baseline phases then alternated with disruption phases where video-clips were embedded into the top right corner of the simulations. The rate at which participants gambled during baseline was compared to the rate at which they gambled when the videos were present, with bigger relative decreases in response rate during the disruption phases indicating less persistence. The free-spins feature did not cause participants to gamble more persistently. Further experiments also assessed whether different frequencies of wins caused participants to gamble more persistently, and results indicated that they did not. The findings of this research programme have implications for Behavioural Momentum Theory, suggesting that comparing response rate during disruption to response rate during baseline is not highly sensitive to small differences in reinforcement schedules. The findings are also relevant for slot-machine legislation, providing an indication that limiting or removing free-spins features may reduce player enjoyment without reducing persistent gambling. Furthermore, the task developed in the persistence investigation provides a useful tool which can be used to investigate how other features of slot machines influence persistence. Future research could, for example, investigate how free-spins features interact with other slot-machine features to influence gambling behaviour.</p>

The near win effect on observing behaviour in simulated slot-machine gambling: The role of conditioned reinforcement

<p>Slot machines are a remarkably popular mode of gambling even though they are programmed to make a profit by paying out less money than is put in. One common feature of slot machines, which may increase the likelihood of persistent gambling in the face of this monetary loss, is the near win. This study’s aim was to investigate the conditioned reinforcing properties of near wins using an observing response procedure in the context of a simulated slot machine. In an observing response procedure, participants can use an observing button to produce a stimulus correlated with the availability of reinforcement (S+) or a stimulus correlated with no reinforcement or less reinforcement (S-). The percentage of observing responses made for each stimulus is thought to reflect the reinforcing efficacy of the reinforcer correlated with each stimulus. Experiment 1 successfully tested the procedure with an obvious reinforcer - wins - and found consistently more observing for the S+. In Experiment 2 and 3 the S+ was correlated with near wins, and in Experiment 2 only those with slot-machine experience had consistently more observing for the S+. Experiment 3 increased the probability of wins to enhance the reinforcing efficacy of near wins, but failed to find consistently more observing for the S+, regardless of slot machine or scratchie card experience. These results indicated that near wins are not conditioned reinforcers. However, participants tended to bet more following near wins than losses, which suggested that near wins may instead function as discriminative stimuli.</p>

The near win effect on observing behaviour in simulated slot-machine gambling: The role of conditioned reinforcement

<p>Slot machines are a remarkably popular mode of gambling even though they are programmed to make a profit by paying out less money than is put in. One common feature of slot machines, which may increase the likelihood of persistent gambling in the face of this monetary loss, is the near win. This study’s aim was to investigate the conditioned reinforcing properties of near wins using an observing response procedure in the context of a simulated slot machine. In an observing response procedure, participants can use an observing button to produce a stimulus correlated with the availability of reinforcement (S+) or a stimulus correlated with no reinforcement or less reinforcement (S-). The percentage of observing responses made for each stimulus is thought to reflect the reinforcing efficacy of the reinforcer correlated with each stimulus. Experiment 1 successfully tested the procedure with an obvious reinforcer - wins - and found consistently more observing for the S+. In Experiment 2 and 3 the S+ was correlated with near wins, and in Experiment 2 only those with slot-machine experience had consistently more observing for the S+. Experiment 3 increased the probability of wins to enhance the reinforcing efficacy of near wins, but failed to find consistently more observing for the S+, regardless of slot machine or scratchie card experience. These results indicated that near wins are not conditioned reinforcers. However, participants tended to bet more following near wins than losses, which suggested that near wins may instead function as discriminative stimuli.</p>

Investigating the Role of Language in Slot Machine Gambling

<p>A systematic replication of Dixon, Nastally, Jackson and Habib (2009) was carried out to further examine the role of relational framing in attaching meaning to near-win stimuli in a slot machine simulation. The original study found that the verbally reported meaning of near-win stimuli could be altered through a verbal matching-to-sample training procedure. The current study confirmed this finding. Additionally this study had participants play on a simulated slot machine to assess if such relational training also resulted in changes in (non-verbal) response latencies when participants were presented with near-win outcomes during play. A study by Daly et al. (in prep.) had found that near-wins produced response latencies (in terms of initiating a new trial or 'spin') between that of wins and losses during slot machine play; a general finding replicated here also. However, in the current study it was also expected that changes to the meanings of near-wins would influence near-win response latencies. For example, response latencies following near-wins might become more like latencies following losses as a result of prior relational framing of near-win stimuli. The results of this study found a dissociation between verbal and non-verbal responses to near-win stimuli. The verbal training affected verbal responses but did not affect non-verbal responses. Some explanations are postulated for why this happened. These include the possibility that the near-win latency was merely an artefact of the experimental paradigm. Another explanation is that the dissociation between response types occurred because the contexts in the ratings and verbal training tasks were different to the context of the slot machine task.</p>

Investigating the Role of Language in Slot Machine Gambling

<p>A systematic replication of Dixon, Nastally, Jackson and Habib (2009) was carried out to further examine the role of relational framing in attaching meaning to near-win stimuli in a slot machine simulation. The original study found that the verbally reported meaning of near-win stimuli could be altered through a verbal matching-to-sample training procedure. The current study confirmed this finding. Additionally this study had participants play on a simulated slot machine to assess if such relational training also resulted in changes in (non-verbal) response latencies when participants were presented with near-win outcomes during play. A study by Daly et al. (in prep.) had found that near-wins produced response latencies (in terms of initiating a new trial or 'spin') between that of wins and losses during slot machine play; a general finding replicated here also. However, in the current study it was also expected that changes to the meanings of near-wins would influence near-win response latencies. For example, response latencies following near-wins might become more like latencies following losses as a result of prior relational framing of near-win stimuli. The results of this study found a dissociation between verbal and non-verbal responses to near-win stimuli. The verbal training affected verbal responses but did not affect non-verbal responses. Some explanations are postulated for why this happened. These include the possibility that the near-win latency was merely an artefact of the experimental paradigm. Another explanation is that the dissociation between response types occurred because the contexts in the ratings and verbal training tasks were different to the context of the slot machine task.</p>