Department of Psychology, University of Denver, 2155 South Race Street, Denver, CO, 80208, USA.
Psychol Res. 2023 Nov;87(8):2477-2498. doi: 10.1007/s00426-023-01829-5. Epub 2023 Apr 20.
Reward benefits to memory formation have been robustly linked to dopaminergic activity. Despite the established characterization of dopaminergic mechanisms as operating at multiple timescales, potentially supporting distinct functional outcomes, the temporal dynamics by which reward might modulate memory encoding are just beginning to be investigated. In the present study, we leveraged a mixed block/event experimental design to disentangle transient and sustained reward influences on task engagement and subsequent recognition memory in an adapted monetary-incentive-encoding (MIE) paradigm. Across three behavioral experiments, transient and sustained reward modulation of item and context memory was probed, at both 24-h and ~ 15-min retention intervals, to investigate the importance of overnight consolidation. In general, we observed that transient reward was associated with enhanced item memory encoding, while sustained reward modulated response speed but did not appear to benefit subsequent recognition accuracy. Notably, reward effects on item memory performance and response speed were somewhat inconsistent across the three experiments, with suggestions that RT speeding might also be related to time on task, and we did not observe reward modulation of context memory performance or amplification of reward benefits to memory by overnight consolidation. Taken together, the observed pattern of behavior is consistent with potentially distinct roles for transient and sustained reward in memory encoding and cognitive performance and suggests that further investigation of the temporal dynamics of dopaminergic contributions to memory formation will advance the understanding of motivated memory.
奖励对记忆形成的益处与多巴胺能活动密切相关。尽管多巴胺能机制的特征已经被确立为在多个时间尺度上运作，可能支持不同的功能结果，但奖励调节记忆编码的时间动态才刚刚开始被研究。在本研究中，我们利用混合块/事件实验设计，在改编的货币激励编码（MIE）范式中，分离短暂和持续的奖励对任务参与度和随后的识别记忆的影响。在三个行为实验中，在 24 小时和~15 分钟的保留间隔内，探究了隔夜巩固的重要性，探究了项目和上下文记忆的短暂和持续奖励调节。总的来说，我们观察到，短暂的奖励与增强的项目记忆编码相关，而持续的奖励调节反应速度，但似乎不会提高随后的识别准确性。值得注意的是，奖励对项目记忆表现和反应速度的影响在三个实验中有些不一致，这表明 RT 加速可能也与任务时间有关，而且我们没有观察到上下文记忆表现的奖励调节或隔夜巩固对记忆奖励的放大。总之，观察到的行为模式与记忆编码和认知表现中短暂和持续奖励的潜在不同作用一致，并表明对多巴胺能对记忆形成的贡献的时间动态的进一步研究将推进对动机记忆的理解。
