Neuronal evidence for good-based economic decisions under variable action costs

Previous work showed that economic decisions can be made independently of spatial contingencies. However, when goods available for choice bear different action costs, the decision necessarily reflects aspects of the action. One possibility is that "stimulus values" are combined with the corresponding action costs in a motor representation, and decisions are then made in actions space. Alternatively, action costs could be integrated with other determinants of value in a non-spatial representation. If so, decisions under variable action costs could take place in goods space. Here, we recorded from orbitofrontal cortex while monkeys chose between different juices offered in variable amounts. We manipulated action costs by varying the saccade amplitude, and we dissociated in time and space offer presentation from action planning. Neurons encoding the binary choice outcome did so well before the presentation of saccade targets, indicating that decisions were made in goods space.

先前的研究表明，经济决策可以独立于空间关联性而做出。然而，当可供选择的物品具有不同的行动成本时，决策必然会反映行动的各个方面。一种可能性是，“刺激值”在运动表征中与相应的行动成本相结合，然后在行动空间中做出决策。或者，行动成本可以在非空间表征中与价值的其他决定因素整合。如果是这样，在可变行动成本下的决策可能发生在物品空间中。在这里，我们在猴子对不同数量的果汁进行选择时记录了眶额皮质的活动。我们通过改变扫视幅度来操纵行动成本，并且在时间和空间上将提供物呈现与行动计划分离开来。对二元选择结果进行编码的神经元在扫视目标呈现之前就很好地完成了编码，这表明决策是在物品空间中做出的。