Teichert Tobias, Ferrera Vincent P
Department of Neuroscience, Columbia University New York, NY, USA.
Front Neurosci. 2010 Nov 19;4:186. doi: 10.3389/fnins.2010.00186. eCollection 2010.
Sensory decisions may be influenced by non-sensory information regarding reward magnitude or reward likelihood. Given identical sensory information, it is more optimal to choose an option if it is a priori more likely to be correct and hence rewarded (prior reward likelihood bias), or if it yields a larger reward, given that it is the correct choice (reward magnitude bias). Here, we investigated the ability of macaque monkeys to integrate reward magnitude and prior reward likelihood information into a categorical decision about stimuli with high signal strength but variable decision uncertainty. In the asymmetric reward magnitude condition, monkeys over-adjusted their decision criterion such that they chose the highly rewarded alternative far more often than was optimal; in contrast, monkeys did not adjust their decision criterion in response to asymmetric reward likelihood. This finding shows that in this setting, monkeys did not adjust their decision criterion based on the product of reward likelihood and reward magnitude as has been reported to be the case in value-based decisions that do not involve decision uncertainty due to stimulus categorization.
感觉决策可能会受到有关奖励大小或奖励可能性的非感觉信息的影响。在相同的感觉信息下，如果一个选项先验上更有可能是正确的并因此得到奖励（先验奖励可能性偏差），或者如果它是正确选择时会带来更大的奖励（奖励大小偏差），那么选择该选项会更优。在这里，我们研究了猕猴将奖励大小和先验奖励可能性信息整合到关于具有高信号强度但决策不确定性可变的刺激的分类决策中的能力。在不对称奖励大小条件下，猴子过度调整了它们的决策标准，以至于它们选择高奖励选项的频率远远超过了最优频率；相比之下，猴子并没有根据不对称的奖励可能性来调整它们的决策标准。这一发现表明，在这种情况下，猴子并没有像在不涉及因刺激分类导致决策不确定性的基于价值的决策中所报道的那样，根据奖励可能性和奖励大小的乘积来调整它们的决策标准。
