Comparative Psychology, Institute of Experimental Psychology, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany
Department of Cognitive Science and Artificial Intelligence, Tilburg University, Tilburg 5037 AB, The Netherlands.
J Neurosci. 2021 May 19;41(20):4448-4460. doi: 10.1523/JNEUROSCI.2541-20.2021. Epub 2021 Mar 22.
Demand theory can be applied to analyze how animal consumers change their selection of commodities in response to changes in commodity prices, given budget constraints. Previous work has shown that demand elasticities in rats differed between uncompensated budget conditions in which the budget available to be spent on the commodities (e.g., the finite number of discrete operants to "purchase" rewards in two-alternative fixed-ratio schedules) was kept constant, and compensated budget conditions in which the budget was adjusted so that consumers could potentially continue to obtain the original reward bundles. Here, we hypothesized that rat anterior cingulate cortex (ACC) was necessary to produce this budget effect on demand elasticities. We applied excitotoxic or sham lesions to ACC in rats performing an effort task in which the prices of liquid vanilla or chocolate rewards (the effort required to obtain rewards) and the budget (the total number of operants) was manipulated. When reward prices changed, and the budget was compensated, all rats adjusted their demand for chocolate and vanilla accordingly. In sham-lesioned rats, changes in demand were even more pronounced when the budget was not compensated for the price changes. By contrast, ACC-lesioned animals did not show this additional budget effect. An in-depth comparison of the rats' choice patterns showed that, unlike sham rats, ACC-lesioned animals failed to maximize session-bundle utility after price/budget changes, revealing deficits in higher-order choice-strategy adaptations. Our results suggest a novel role of ACC in considering purchasing power during complex cost-benefit value computations. Anterior cingulate cortex (ACC) is important for allocating effort in cost-benefit calculations in animals and humans. Economic theory prescribes that the value of the costs in cost-benefit analyses not only depends on the net nominal costs required to purchase a reward, but also on the available budget resources, i.e., on the budget's "purchasing value." We asked whether ACC, a region implicated in effort-based decision-making and reward comparisons, is required for computing the value of effort relative to a budget constraint. Applying demand theory to describe rat choices in a rodent effort allocation task with varying effort prices and budgets, we show that ACC integrity was necessary for computing purchasing power, a core variable in economic choice theory.
需求理论可用于分析动物消费者如何在预算限制的情况下，根据商品价格的变化改变对商品的选择。先前的工作表明，在非补偿预算条件下，大鼠的需求弹性在不同之处在于，可用的预算（例如，在二选一固定比率时间表中“购买”奖励的有限数量离散操作）保持不变，而在补偿预算条件下，预算会进行调整，以便消费者可以继续获得原始的奖励包。在这里，我们假设大鼠前扣带皮层（ACC）是产生这种预算对需求弹性影响所必需的。我们在大鼠中应用兴奋性毒性或假损伤来执行一项努力任务，在该任务中，液体香草或巧克力奖励的价格（获得奖励所需的努力）和预算（总操作数）被操纵。当奖励价格发生变化且预算得到补偿时，所有大鼠都相应地调整了对巧克力和香草的需求。在假损伤大鼠中，当预算未因价格变化而得到补偿时，需求的变化更为明显。相比之下，ACC 损伤动物没有表现出这种额外的预算效应。对大鼠选择模式的深入比较表明，与假损伤大鼠不同，ACC 损伤动物在价格/预算变化后未能最大化会话捆绑效用，这表明在高阶选择策略适应方面存在缺陷。我们的结果表明，ACC 在进行复杂的成本效益值计算时，在考虑购买力方面具有新的作用。ACC 在动物和人类的成本效益计算中分配努力的重要性。经济理论规定，成本效益分析中的成本价值不仅取决于购买奖励所需的净名义成本，还取决于可用的预算资源，即预算的“购买价值”。我们想知道，ACC，一个与基于努力的决策和奖励比较有关的区域，是否需要计算相对于预算约束的努力的价值。我们通过应用需求理论来描述大鼠在具有不同努力价格和预算的啮齿动物努力分配任务中的选择，表明 ACC 完整性对于计算购买力是必要的，购买力是经济选择理论中的一个核心变量。
