Department of Neuroscience, University of Lethbridge, EP 1219, 4401 University Drive W, Lethbridge, AB, T1K 6T5, Canada.
Vision and Cognitive Neuroscience Lab, Department of Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, ON, Canada.
J Gambl Stud. 2018 Mar;34(1):181-197. doi: 10.1007/s10899-017-9705-3.
Gambling studies have described a "near-miss effect" wherein the experience of almost winning increases gambling persistence. The near-miss has been proposed to inflate the value of preceding actions through its perceptual similarity to wins. We demonstrate here, however, that it acts as a conditioned stimulus to positively or negatively influence valuation, dependent on reward expectation and cognitive engagement. When subjects are asked to choose between two simulated slot machines, near-misses increase valuation of machines with a low payout rate, whereas they decrease valuation of high payout machines. This contextual effect impairs decisions and persists regardless of manipulations to outcome feedback or financial incentive provided for good performance. It is consistent with proposals that near-misses cause frustration when wins are expected, and we propose that it increases choice stochasticity and overrides avoidance of low-valued options. Intriguingly, the near-miss effect disappears when subjects are required to explicitly value machines by placing bets, rather than choosing between them. We propose that this task increases cognitive engagement and recruits participation of brain regions involved in cognitive processing, causing inhibition of otherwise dominant systems of decision-making. Our results reveal that only implicit, rather than explicit strategies of decision-making are affected by near-misses, and that the brain can fluidly shift between these strategies according to task demands.
赌博研究描述了一种“近失效应”，即几乎获胜的经历会增加赌博的持久性。近失被认为通过其与胜利的感知相似性来夸大先前行为的价值。然而，我们在这里证明，它可以作为一种条件刺激，根据奖励预期和认知参与度，积极或消极地影响估值。当被试被要求在两台模拟老虎机之间进行选择时，近失会增加低回报率机器的估值，而降低高回报机器的估值。这种上下文效应会损害决策，并且无论对结果反馈进行何种操作，或者对良好表现提供的财务激励进行操作，都会持续存在。这与近失在预期获胜时会导致挫折的观点一致，我们提出，它会增加选择的随机性，并忽略低价值选项的回避。有趣的是，当被试被要求通过下注而不是在两者之间进行选择来明确评估机器时，近失效应就会消失。我们提出，这个任务增加了认知参与度，并招募了参与认知处理的大脑区域，从而抑制了否则占主导地位的决策系统。我们的结果表明，只有隐性的、而不是显性的决策策略受到近失的影响，并且大脑可以根据任务需求灵活地在这些策略之间切换。
