Distributed hippocampal patterns that discriminate reward context are associated with enhanced associative binding.
Distributed hippocampal patterns that discriminate reward context are associated with enhanced associative binding.
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DOI：
10.1037/a0033609
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发表时间：
2013-11
期刊：
影响因子：
--
通讯作者：
Preston AR
中科院分区：
文献类型：
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作者：
Wolosin SM;Zeithamova D;Preston AR
最近的研究表明，基于奖赏的动机影响内侧颞叶(MTL)的编码过程，导致对奖赏事件的记忆增强。特别是，先前对动机学习的功能磁共振成像(FMRI)研究表明，高奖励事件的MTL激活更大，与奖励相关的激活增强程度跟踪相应的行为记忆优势。然而，这些研究并没有直接涉及主要的理论观点，这些观点认为MTL编码激活中基于奖励的增强反映了对特定事件的动机背景的增强辨别。在这项研究中，一条高价值或低价值的货币线索位于一对物体之前，表明成功记住这两个物体的未来奖励。使用表征相似性分析和高分辨率功能磁共振成像，我们发现MTL激活模式在编码相同和不同奖励线索的试验中更相似，表明该区域存在区分动机情境的分布式代码。此外，我们还发现，在预期线索和目标对中区分奖励条件的海马区和PHC区的激活模式与成功的联想记忆有关。此外，在齿状回/CA2，3和PHC中，模式区分奖赏背景的程度与记忆奖赏调制的个体差异有关。总而言之，这些发现表明，人类海马体和PHC中的分布式激活模式反映了与个别事件相关的奖励。此外，我们还表明，这些区分奖励条件的激活模式可能会通过将有关动机背景的信息合并到存储的记忆表征中来影响记忆。
Recent research indicates that reward-based motivation impacts medial temporal lobe (MTL) encoding processes, leading to enhanced memory for rewarded events. In particular, previous functional magnetic resonance imaging (fMRI) studies of motivated learning have shown that MTL activation is greater for highly rewarded events, with the degree of reward-related activation enhancement tracking the corresponding behavioral memory advantage. These studies, however, do not directly address leading theoretical perspectives that propose such reward-based enhancements in MTL encoding activation reflect enhanced discrimination of the motivational context of specific events. In this study, a high-value or low-value monetary cue preceded a pair of objects, indicating the future reward for successfully remembering the pair. Using representational similarity analysis and high-resolution fMRI, we show that MTL activation patterns are more similar for encoding trials preceded by the same versus different reward cues, indicating a distributed code in this region that distinguishes between motivational contexts. Moreover, we show that activation patterns in hippocampus and PHc that differentiate reward conditions during anticipatory cues and object pairs relate to successful associative memory. Additionally, the degree to which patterns differentiate reward contexts in dentate gyrus/CA2,3 and PHc is related to individual differences in reward modulation of memory. Collectively, these findings suggest that distributed activation patterns in the human hippocampus and PHc reflect the rewards associated with individual events. Furthermore, we show that these activation patterns—which discriminate between reward conditions—may influence memory through the incorporation of information about motivational contexts into stored memory representations.