Just Missing the Jackpot: Why I am never going to a Casino again.

Written by João Costa



Dixon, M. J., MacLaren, V., Jarick, M., Fugelsang, J. A., & Harrigan, K. A. (2012). The frustrating effects of just missing the jackpot: slot machine near-misses trigger large skin conductance responses, but no post-reinforcement pauses. Journal of Gambling Studies, 1-14.


Near-misses in slot machines resemble jackpot wins but fall short by just one symbol (I for one like to think as near-hits, not near-misses). What is curious about these near-misses is that previous research has shown that they are behaviourally reinforcing, despite the lack of monetary reward.

The authors investigated the pleasing properties of these near-misses, in comparisson to regular wins and losses, by measuring the time between spins called Post-Reinforcement Pause (PRP), while also gathering Skin Conductance Response (SCR) data. For this matter, they recruited players with different gambling backgrounds and had them play slot machine sessions.

The results indicate that near-misses with jackpot symbols on the first two reels exhibit a significantly larger SCR than losses, while also exhibiting a significantly smaller PRP. This pattern suggests that these near-miss moments are highly frustrating outcomes that stimulate appetitive components of our body and, thus, promote gambling.


A near-miss is when the outcome of the slot machine resembles a jackpot win, but falls short for one symbol. A classic near-miss would be two red 7s on the payline and the third 7 just above or below the line. These events, the near-misses, ar important because of their psychological and psychophysiological influence on the player. They have been reported, by previous research, to be perceived as misconstrued wins and to foster continued gambling by promoting extended play. To quote the paper, “if these excessive gamblers become physiologically aroused when they win or nearly win, then in their minds they are not constantly losing but constantly nearly winning”.

It is this cognitive misinterpretation (or misrepresentation) that is related to the illusion of control. After all, you are always so close to winning (and not constantly losing). For certain gamblers, this illusion is so powerful that a near-miss is seen as a reflection of their skill that enables them to get very close to the jackpot.

Clark et.al. [1] investigated conducted this research on near-misses in slightly different conditions with a two-reel slot machine simulator: near-miss symbols were either randomly selected by the computer or player selected. The participants who had the illusory control over the near-miss symbol rated their chances of winning to be significantly higher than those who did not have control over the to-match symbol. Moreover, participants reported near-misses to be as even more unpleasant than regular loses, being associated with greater urges to continue playing.

In the same study, Clark et.al. had participants undergo functional Magnetic Resonance Imaging (fMRI) while playing their slot machine simulator. Their results indicated that, for non-problem gamblers, the areas activated by wins were distinct from the areas activated by near-misses. However, for problem gamblers, wins and near-misses activated overlapping areas of the brain. This indicated that near-misses activate brain structures that are widely known to be part of a subcortical system that mediates behavioural reinforcement.

Although being unpleasant outcomes, near-misses were shown to activate areas of the brain associated with reward, a puzzling result caused by our non-homogenous mesolimbic system. This system has, at least, two components: the consummatory reward component, responsible for the subjective ‘liking’ of exciting enjoyment; and the appetitive component, responsible for generating the anticipatory ‘wanting’ of opportunities that lead to satisfaction of needs. In another study also conducted by Clark et. al., [2], using the same two-reel simulator, psychophysiological responses were sought after, using SCR. In this study, near-misses led to higher SCRs than full losses, but only when the gambler chose the to-be-matched symbol, which goes in line with the illusion of control that these events enable on the player.

Previous studies also cited looking upon the Post-Response Pauses (PRP) on different outcomes, showing that the PRP increased with the magnitude of the win. The bigger the win, the longer the pause. This constituted one of the authors’ hypotheses, which is that large PRPs for pleasurable outcomes and no PRPs for frustrating outcomes should be identifiable. The authors also sought to demonstrate that SCR amplitute would also scale with the win size. If near-misses are misclassified as wins, then they should stimulate the consummatory reward component of our body, and consequently have longer PRPs than regular loses. Also, if near-misses are interpreted as frustrating loses, then the consummatory reward component should not be activated, because we do not like the outcome, and the PRP duration following near-misses should be shorter than for regular loses  (or have the same duration at most).

The method adopted by the authors consisted in testing 122 players in total for both skin conductance response and post-response pauses when playing on a slot machine simulator (recruited from Kijiji.ca). The participants were assessed in regards to their Problem Gambling Severity Index (PGSI), constituting a diversified population of non-problem gamblers, at risk, and problem gamblers. The slot machine simulator used was tailored to accurately represent the characteristics of a real slot machine, playing a winning song of fixed length for all the wins while exhibiting flashing symbols when such event happens. When the player loses, however, no jingle or flashing symbols are present. All the other aspects of a real slot machine are simulated in this software like bet size, spin outcome displays and others. Participants played a series of 12 experimental blocks of 40 spins each, divided in two experiments.

PRP increased, for winning outcomes, as the credit value increased. Nevertheless, the PRP duration for classic  near-misses was shorter than the one present in loses, reflecting the undesirable or ‘unpleasant’ effect of these events (more unpleasant than loses).

The authors also found that not just the PRP, but also the SCR, scales with the credit size of the win, which goes in line with their hypothesis.

Lastly, the authors also obtained a peculiar result. Classic near-misses, where the jackpot symbol misses the last reel by being one position above or below, have a higher SCR than losses and non-classic near-misses. It is also visible that the order in which the jackpot symbols land on the payline is crucial, visible by the different SCR between both near-miss types. In the non-classic near-miss, both PRP and SCR resemble those of a loss. This combination of large SCRs but short PRP supported the authors’ hypothesis that near-misses are interpreted as frustrating losses rather than misconstrued wins.

If near-misses are frustrating losses, they can increase the propensity to keep playing, fostering gambling, by activating the appetitive component of the mesolimbic reward system, perpetuating the impression that the next win is imminent, thus playing a key role in the addictive behaviour of compulsive gambling.


I enjoyed the deep literature review, particularly the section where some biology and biochemistry come into play. I loved the granularity which the authors went through to explain this addictive behaviour, starting with the simple gesture of pulling the lever, going down to having a mesolimbic reward system that can be triggered by frustration.

I also found the main research topic to be interesting since the authors’ went after an interesting dichotomy, or loop-hole, in the literature. They found good results that ground the fact that near-misses do foster gambling and that are a dangerous thing.

Further References

  1. Clark, L., Lawrence, A. J., Astley-Jones, F., & Gray, N. (2009). Gambling near-misses enhance motivation to gamble and recruit win-related brain circuitry.Neuron61(3), 481-490.
  2. Clark, L., Crooks, B., Clarke, R., Aitken, M. R., & Dunn, B. D. (2012). Physiological responses to near-miss outcomes and personal control during simulated gambling. Journal of Gambling Studies28(1), 123-137.