We investigated the potential influence of circadian photoreception on loss aversion during a gambling task, by manipulating the melanopic brightness of light while controlling for visual brightness. Our results revealed a decrease in loss aversion under blue-enriched light, which has a greater impact on circadian photoreceptors. We also found significant differences in loss aversion between sexes across the two light conditions, with women displaying greater loss aversion compared with men.
我们通过在控制视觉亮度的同时操纵光线亮度，调查了昼夜节律光感受对赌博任务期间损失厌恶的潜在影响。我们的结果表明，在蓝色的光中，损失厌恶的减少减少，这对昼夜节律感受器的影响更大。我们还发现，与男性相比，在两种光照条件下，性别之间的性别损失越明显差异。
Individuals tend to have an unequal balance of evaluations between losses and gains, with losses typically outweighing gains for subsequent behaviour16. Under blue-enriched light, our findings reveal that individuals are less loss averse, suggesting that when under such light, individuals are relatively more comfortable with taking risks and demonstrate a reduced sensitivity to losses compared to gains of equal magnitude. In a gambling scenario, individuals under blue-depleted light might perceive the subjective impact of a $100 loss as significantly larger than the potential $100 gain. However, under blue-enriched light, the subjective impact of a $100 loss may not be as large, leading individuals to have less negative reaction to losses. Manipulations that alter this balance are important for subsequent behaviour as this could affect whether someone decides to continue engaging in gambling activities or discontinuing.
个人往往在损失和收益之间的评估平衡不平等，损失通常超过后续行为的收益16。在富含蓝色的光线下，我们的发现表明，个人的损失较少，这表明，在这样的光线下，个人对冒险相对舒适，并且表现出对损失的敏感性降低，而与幅度相等的增长相比。在赌博场景中，蓝色的光线下的个人可能会认为100美元损失的主观影响大大高于潜在的100美元增长。但是，在富含蓝色的光线下，$ 100损失的主观影响可能不那么大，导致个人对损失的负面反应较少。改变这种平衡的操作对于后续行为很重要，因为这可能会影响某人是否决定继续进行赌博活动或中断。
Our findings demonstrate that individuals exhibit reduced loss aversion under blue-enriched light, while controlling for visual brightness (~ 200 lx for both conditions). As both the spectral quality and intensity of light can impact cognition and several brain regions9,10,12,27, by controlling the visual brightness, we were able to isolate the specific influence of blue content on circadian photoreceptors, which are known to affect brain regions associated with decision-making. It is possible that reduced loss aversion under blue-enriched light may be due to the effect of light, via ipRGCs (which preferentially respond to blue light8), on specific brain regions. In rodents, ipRGCs have been found to innervate the amygdala28, a structure that plays a pivotal role in reward processing29 and is part of an impulsive system that triggers emotional responses to immediate outcomes30. The amygdala is believed to play an important role in evaluating the subjective appeals and disadvantages of potential gains and losses during mixed gambles31. Previous work has found an association between reduced amygdala response to loss and emotional regulation strategies, including reappraisal (i.e., reframing how individuals think about outcomes)22,32, with damage to the amygdala reducing loss aversion33. As bright light suppresses amygdala activity12, exposure to blue-enriched light may reduce negative emotions and the ability to evaluate subjective appeals, resulting in individuals being less averse to potential losses.
我们的发现表明，在富含蓝色的光线下，个体在控制视觉亮度的同时表现出减少的损失（两种条件下约为200 lx）。由于光的光谱质量和强度都可以影响认知，而且通过控制视觉亮度，我们能够隔离蓝色含量对昼夜节律光感受器的特定影响，这是众所周知，这会影响与决策相关的大脑区域。在蓝色富集的光线下，通过IPRGC（优先响应蓝光8）对特定的大脑区域的影响可能会减少损失厌恶的厌恶。在啮齿动物中，已经发现IPRGC支配了Amygdala28，该结构在奖励处理中起着关键作用29，并且是冲动系统的一部分，它触发了对即时抗癌的情感反应30。据信，杏仁核在评估混合赌博期间潜在损益的主观吸引力和劣势中发挥了重要作用31。先前的工作发现，杏仁核对损失的反应减少与情绪调节策略之间的关联，包括重新评估（即，重新阐述个人对结果的看法）22,32，与降低杏仁核的损害减少了损失aververion33。由于明亮的光抑制了杏仁核活性12，富含蓝色的光的暴露可能会降低负面情绪和评估主观吸引力的能力，从而导致个人对潜在损失的反感较小。
In addition to the amygdala, the habenula plays a role in the decision-making process, including reward regulation13,34. Animal studies suggest that the habenula deters behaviours associated with negative outcomes (e.g., punishment), while reinforcing those linked to positive outcomes, influencing motivation and decision-making35. Specifically, the lateral habenula is implicated in reward prediction. Neurons in the lateral habenula encode negative reward prediction error and are activated by unexpected, non-rewarding and unpleasant events while being suppressed by unexpected rewarding events14. Heightened activation of the lateral habenula may inhibit individuals from accepting risky gambles, guiding them towards safer outcomes and potentially increasing their loss aversion. In humans, light has been found to directly impact habenula activation in fMRI studies15. Through direct input from retinal ganglion cells and other brain structures involved in non-visual photoreception, the impact of light on habenula activation may lead to an elevated expectation of reward, reducing the psychological “pain” typically associated with losses and making individuals less averse to loss35.The brain’s reward system likely contributes to the observed reduction in loss averse behaviour under blue-enriched light. Dopamine, a key neurotransmitter involved in daily functioning, plays a central role in the reward system by processing reward information36,37. Dopamine neurons exhibit responses relative to reward prediction, with unexpected rewards triggering increased activation and expected rewards leading to maintained or decreased activity37,38. Dopamine neurons project to brain regions such as the insula and striatum, where heightened activity in response to gains causes a reduced sensitivity to loss31. These regions are implicated in circadian photoreception, with bright light exposure enhancing their activation7,39,40. This suggests that light can boost activity in reward-related brain regions, potentially amplifying the influence of the reward system. Consequently, individuals may value potential rewards more and find riskier decisions more appealing under blue-enriched light.
除杏仁核外，Habenula在决策过程中发挥了作用，包括奖励法规13,34。动物研究表明，Habenula阻止了与负面结果（例如惩罚）相关的行为，同时加强了与积极结果相关的人，影响了动机和决策35。具体而言，侧向Habenula与奖励预测有关。外侧Habenula中的神经元编码负面奖励预测误差，并被意外的，不奖励和不愉快的事件激活，同时被意外的奖励事件抑制14。外侧Habenula的激活增强可能会抑制个人接受风险的赌博，引导他们取得更安全的结果并可能增加损失的厌恶。在人类中，发现光直接影响fMRI研究中的Habenula激活15。通过来自视网膜神经节细胞和其他参与非视觉光感受的大脑结构的直接输入，光对Habenula激活的影响可能会导致人们对奖励的期望升高，从而减少了与损失相关的心理“疼痛”，并使个人对损失的损失较小。多巴胺是参与日常功能的关键神经递质，通过处理奖励信息36,37在奖励系统中起着核心作用。多巴胺神经元相对于奖励预测表现出反应，意外的奖励触发了激活增加，预期的奖励导致活动或减少活动37,38。多巴胺神经元投射到诸如岛菌和纹状体等大脑区域，其中响应增长的活动提高会导致对损失的敏感性降低31。这些区域与昼夜节律相关，明亮的光暴露增强了其活化7,39,40。这表明光可以增强与奖励相关的大脑区域的活动，从而增加奖励系统的影响。因此，个人可能会更加重视潜在的奖励，并在富含蓝色的光线下找到更具吸引力的风险决定。
In addition to the observed effects of light on decision-making processes, we observed substantial interindividual differences in loss aversion. Our findings revealed lower loss aversion among men, consistent with existing literature highlighting sex differences in loss aversion41,42,43,44. Women often experience more negative emotions (e.g., fear), leading to a lower willingness to undertake financial risk (e.g., invest less money or gamble less)45,46. Conversely, men tend to experience more positive emotions associated with gambling (e.g., optimism and confidence), which may predispose them to underestimate negative outcomes45,46,47. Furthermore, neurobiological differences may play a role, as men and women have shown disparities in brain regions associated with decision-making. For example, men often exhibit activation in regions such as the lateral orbitofrontal cortex (OFC) and DLPFC during risky decision-making, whereas women may show activation primarily in a smaller region of the left medial OFC41,48. Therefore, the observed sex disparities in loss aversion may arise from a complex interplay between emotions and neurobiological differences in brain activation patterns.
除了观察到的光对决策过程的影响外，我们还观察到了损失厌恶厌恶的实质间差异。我们的发现表明，男性的损失较低，这与现有文献一致，强调了损失的性别差异41,42,43,44。妇女经常会经历更多的负面情绪（例如恐惧），从而降低承担财务风险的意愿（例如，投入更少的钱或赌博更少）45,46。相反，男人倾向于经历与赌博相关的更多积极情绪（例如乐观和信心），这可能会使他们低估了负面结果45,46,47。此外，神经生物学差异可能起作用，因为男人和女性在与决策相关的大脑区域表现出差异。例如，在风险决策过程中，男性经常在诸如横向轨道额皮层（OFC）和DLPFC等地区表现出激活，而女性可能主要在C41,48的左侧较小区域中表现出激活。因此，观察到的性别厌恶厌恶性差异可能是由于情绪与脑激活模式中神经生物学差异之间的复杂相互作用引起的。
There are substantial interindividual differences in light sensitivity mediated by circadian photoreception. Previous work has found a greater than 50-fold difference in sensitivity to evening light, with some individuals exhibiting > 50% melatonin suppression (a marker of light sensitivity) in response to dim light (~ 10 lx), while less sensitive individuals required ~ 400 lx (equivalent to bright office lights) to achieve the same melatonin suppression49. Several factors are associated with individual differences in light sensitivity, with younger individuals exhibiting higher sensitivity to light compared with older populations50,51,52. Additionally, increased sensitivity of the circadian system to light has been found among individuals with bipolar disorder, with increased sensitivity to light suggested to be a trait marker of bipolar disorder48,49. Younger adults are more likely to engage in risky gambling behaviour53,54,55,56, and the risk of problem gambling is four times higher in patients with bipolar disorder than the general population57. If gambling behaviour and loss aversion are influenced by circadian photoreception, it is likely that individuals with higher light sensitivity would experience less of an impact to loss and therefore gamble more than individuals who are less sensitive to light.
昼夜节律介导的光灵敏度存在很大的个体差异。先前的工作发现对夜灯的敏感性差异超过50倍，有些人表现出> 50％的褪黑激素抑制（光敏度标记），以响应昏暗的光（〜10 lx），而敏感的个体则较低，而敏感的个体则需要〜400 lx（相当于明亮的办公室光）才能实现相同的褪黑激素抑制49。几个因素与光灵敏度的个体差异有关，与较老的人群相比，年轻人对光的敏感性更高。此外，在双相情感障碍的个体中发现了昼夜节律系统对光的灵敏度的提高，对光的敏感性提高，认为是双相情感障碍的特征标记48,49。年轻人更有可能从事风险的赌博行为53,54,55,56，并且躁郁症患者的问题赌博风险是一般人群的四倍。如果赌博行为和损失受到昼夜节律光感受的影响，那么较高的光灵敏度的个体可能会对损失产生较小的影响，因此比对光敏感较低的个人更大。
It should be noted that this study had a relatively small sample size for computational modelling58,59. However, our model diagnostics indicated that the MCMC samples converged with values less than 1.1, highlighting reliability in the model estimates19. Furthermore, the within-subjects design of our study substantially boosted statistical power. However, given the small sample size and sex imbalance, additional studies of light condition and loss aversion are needed as it is possible that this limitation may have masked potential interactions of sex by light condition on loss aversion. Furthermore, with respect to interpretation of the findings, while the visual brightness of both conditions was equivalent, we were unable to exclude the role of differences in visual experience between the light conditions.
应该注意的是，这项研究的计算模型样本量相对较小，为58,59。但是，我们的模型诊断表明，MCMC样品的值融合了小于1.1，在模型估计中突出了可靠性19。此外，我们研究的受试者内部设计大大提高了统计能力。但是，鉴于样本量和性别不平衡较小，需要对光条件和损失厌恶的额外研究，因为这种限制可能会通过损失厌恶的情况下通过光条件掩盖了性别的潜在相互作用。此外，关于发现结果的解释，尽管两种条件的视觉亮度相同，但我们无法排除光条件之间视觉体验差异的作用。
The ability to control our light environment is a relatively recent development. In our natural history, light exposure was largely determined by the rise and fall of the sun. Humans now spend ~ 90% indoors under artificial light60, and with the growing dominance of energy-efficient LED lights, this light tends to be more blue-enriched, leading to increased activation of circadian photoreception. Virtually all machines used for gambling, including slot machines, now employ LED/LCD displays which are known for their high light intensity and blue-enriched light content. Furthermore, with the prevalence of online gambling increasing, individuals are turning to devices that are likely to emit blue-enriched light (e.g., smartphones and tablets). Exposure to blue-enriched displays possibly contributes to increased gambling behaviour, by reducing an individual’s loss aversion, thereby making them more likely to select uncertain financial outcomes over guaranteed, safer choices. Targeting the reduction of “blue” light content in gambling scenarios may be a promising target for reducing gambling behaviour by promoting greater loss sensitivity.
控制我们的光环境的能力是一个相对较新的发展。在我们的自然历史上，光暴露在很大程度上取决于太阳的兴衰。现在，人类在人造光60下花费了约90％的室内，并且随着能源有效的LED灯的占主导地位，这种灯往往更富含蓝色，从而增加了昼夜节律光感受的激活。几乎所有用于赌博的机器，包括老虎机，现在使用的LED/LCD显示器，它们以其高光强度和富含蓝色的光内容而闻名。此外，随着在线赌博的普遍性增加，个人正在转向可能发出富含蓝色的光线的设备（例如智能手机和平板电脑）。通过减少个人的损失厌恶，可能会导致赌博行为的增加，从而使他们更有可能选择不确定的财务成果，而不是保证，更安全的选择。通过促进更大的损失敏感性来降低赌博场景中“蓝色”光内容的降低可能是降低赌博行为的有希望的目标。
