Measuring and Modeling the Interaction Among Reward Size, Delay to Reward, and Satiation Level on Motivation in Monkeys
Measuring and Modeling the Interaction Among Reward Size, Delay to Reward, and Satiation Level on Motivation in Monkeys
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DOI：
10.1152/jn.90959.2008
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发表时间：
2009-01-01
影响因子：
2.5
通讯作者：
Richmond, Barry J.
中科院分区：
文献类型：
--
作者：
Minamimoto, Takafumi;La Camera, Giancarlo;Richmond, Barry J.
Minamimoto T，La Camera G，里士满BJ.奖赏大小、奖赏延迟与饱足水平对猴子动机交互作用的测量与建模。神经生理学杂志101：437 - 447，2009年。首次发表于2008年11月5日; doi：10.1152/jn.90959.2008。动机通常是从行为的可能性或强度来推断的。它对外部因素很敏感（例如，例如，在一个实施例中，奖励结果的身份、数量和时间）和内部因素（例如，例如，在一个实施例中，饥饿或口渴）。我们训练猕猴执行一个非选择工具任务（一个连续的红绿颜色歧视），同时操纵两个外部因素：奖励大小和延迟奖励。我们还推断了一个内部因素的状态，饱足水平，通过监测累积的奖励。视觉提示表明即将到来的奖励大小和延迟奖励在每个试验。猴子正确完成试验的比例随着奖励大小而线性增加，并且随着奖励延迟持续时间而呈双曲线折扣，这种关系与自由操作和选择任务中发现的关系类似。正确试验的分数也随着饱足水平的变化而逐渐下降。类似的（虽然噪音）的关系，得到了反应时间。奖励大小、延迟奖励和满足水平对正确试验比例的综合影响被很好地描述为当单独检查每个因素时单个因素的影响的倍增。这些结果提供了一个定量的外部和内部因素的相互作用的工具性行为，并允许我们扩展的概念，主观价值的奖励结果，通常局限于外部因素，也占缓慢变化的内部驱动器的主题。
Minamimoto T, La Camera G, Richmond BJ. Measuring and modeling the interaction among reward size, delay to reward and satiation level on motivation in monkeys. J Neurophysiol 101: 437-447, 2009. First published November 5, 2008; doi:10.1152/jn.90959.2008. Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e. g., the identity, amount, and timing of a rewarding outcome) and internal factors (e. g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations that are similar to those found in free operant and choice tasks. The fraction of correct trials also decreased progressively as a function of the satiation level. Similar (albeit noiser) relations were obtained for reaction times. The combined effect of reward size, delay-to-reward, and satiation level on the proportion of correct trials is well described as a multiplication of the effects of the single factors when each factor is examined alone. These results provide a quantitative account of the interaction of external and internal factors on instrumental behavior, and allow us to extend the concept of subjective value of a rewarding outcome, usually confined to external factors, to account also for slow changes in the internal drive of the subject.