Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
J Neurosci. 2012 May 2;32(18):6304-11. doi: 10.1523/JNEUROSCI.6281-11.2012.
The influence of monetary loss on decision making and choice behavior is extensively studied. However, the effect of loss on sensory perception is less explored. Here, we use conditioning in human subjects to explore how monetary loss associated with a pure tone can affect changes in perceptual thresholds for the previously neutral stimulus. We found that loss conditioning, when compared with neutral exposure, decreases sensitivity and increases perceptual thresholds (i.e., a relative increase in the just-noticeable-difference). This was so even when compared with gain conditioning of comparable intensity, suggesting that the finding is related to valence. We further show that these perceptual changes are related to future decisions about stimuli that are farther away from the conditioned one (wider generalization), resulting in overall increased and irrational monetary loss for the subjects. We use functional imaging to identify the neural network whose activity correlates with the deterioration in sensitivity on an individual basis. In addition, we show that activity in the amygdala was tightly correlated with the wider behavioral generalization, namely, when wrong decisions were made. We suggest that, in principle, less discrimination can be beneficial in loss scenarios, because it assures an accurate and fast response to stimuli that resemble the original stimulus and hence have a high likelihood of entailing the same outcome. But whereas this can be useful for primary reinforcers that can impact survival, it can also underlie wrong and costly behaviors in scenarios of contemporary life that involve secondary reinforcers.
货币损失对决策和选择行为的影响已得到广泛研究。然而，损失对感官知觉的影响则较少被探索。在这里，我们利用人类被试的条件作用来研究与纯音相关的货币损失如何影响先前中性刺激的感知阈值变化。我们发现，与中性暴露相比，损失条件作用会降低敏感性并增加感知阈值（即，可察觉差异的相对增加）。与可比强度的增益条件作用相比也是如此，这表明该发现与效价有关。我们进一步表明，这些感知变化与对更远距离的条件刺激的未来决策有关（更广泛的泛化），从而导致受试者总体上增加和不合理的货币损失。我们使用功能成像来识别与个体敏感性恶化相关的神经网络。此外，我们表明杏仁核的活动与更广泛的行为泛化密切相关，即当做出错误决策时。我们认为，原则上，在损失情况下，减少辨别力可能是有益的，因为它可以确保对与原始刺激相似的刺激做出准确和快速的反应，因此极有可能产生相同的结果。但是，尽管这对于可以影响生存的主要强化物可能有用，但在涉及次要强化物的当代生活场景中，它也可能导致错误和昂贵的行为。
