Striatal Activity and Reward Relativity: Neural Signals Encoding Dynamic Outcome Valuation.
Striatal Activity and Reward Relativity: Neural Signals Encoding Dynamic Outcome Valuation.
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DOI：
10.1523/eneuro.0022-16.2016
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发表时间：
2016-09
期刊：
影响因子：
3.4
通讯作者：
Cromwell HC
中科院分区：
文献类型：
--
作者：
Webber ES;Mankin DE;Cromwell HC
纹状体是参与奖赏处理的关键大脑区域。纹状体活动与编码奖励幅度和整合不同的奖励结果信息有关。最近的工作支持纹状体参与评估结果。目前的工作扩展了这一想法，通过检查纹状体活动的动态变化的价值，包括不同的水平和方向的幅度差距。一个新的任务是用来产生不同的相对奖励效应的工具性行动链。大鼠（褐家鼠）接受训练，以对与特定结果相关的线索做出反应，具体结果因食物颗粒大小而异。动物被暴露于单一结果的会议，然后是混合结果的会议，神经活动进行了比较，从不同的行为背景相同的结果试验。记录纹状体活动的结果表明，不同的任务元素的神经反应反映激励对比以及其他相关的影响，涉及结果之间的泛化或结果的多样性的可能影响。最普遍的活动与食物消费和食物消费后时期有关。相对编码对幅度差异敏感。期内分析显示，强烈的对比效应取决于前一次试验的结果。在腹侧纹状体中发现了与相对结果效应相关的显著更高数量的反应。我们的研究结果支持这样一种观点，即相对价值可以包含不同的关系，包括从特定的个人结果到一般行为环境的比较。纹状体包含这些不同的相关过程，可能使更高的信息产量有关的价值转变和更大的行为灵活性。
The striatum is a key brain region involved in reward processing. Striatal activity has been linked to encoding reward magnitude and integrating diverse reward outcome information. Recent work has supported the involvement of striatum in the valuation of outcomes. The present work extends this idea by examining striatal activity during dynamic shifts in value that include different levels and directions of magnitude disparity. A novel task was used to produce diverse relative reward effects on a chain of instrumental action. Rats (Rattus norvegicus) were trained to respond to cues associated with specific outcomes varying by food pellet magnitude. Animals were exposed to single-outcome sessions followed by mixed-outcome sessions, and neural activity was compared among identical outcome trials from the different behavioral contexts. Results recording striatal activity show that neural responses to different task elements reflect incentive contrast as well as other relative effects that involve generalization between outcomes or possible influences of outcome variety. The activity that was most prevalent was linked to food consumption and post-food consumption periods. Relative encoding was sensitive to magnitude disparity. A within-session analysis showed strong contrast effects that were dependent upon the outcome received in the immediately preceding trial. Significantly higher numbers of responses were found in ventral striatum linked to relative outcome effects. Our results support the idea that relative value can incorporate diverse relationships, including comparisons from specific individual outcomes to general behavioral contexts. The striatum contains these diverse relative processes, possibly enabling both a higher information yield concerning value shifts and a greater behavioral flexibility.