Memory-based sequential decision making: neural computations and shaping effects of mood

我们过去的经验如何指导我们对未来的决定？当计划实现一个目标时，我们会唤起过去的相关记忆。例如，我们的记忆包含了发生在我们身上的事情的信息，可能阻碍我们前进的事情，以及这些事情有多好。我们的决定也经常受到情绪的影响。例如，如果你情绪低落，你可以更容易地想象你的计划出错。这种与情绪低落相关的悲观观点，或者与积极情绪相关的乐观观点，可能会影响你追求目标的动力。众所周知，我们的情绪会导致对具有相似情绪质量的记忆的回忆，但我的研究将首次关注这种记忆偏差是如何影响我们的决定的。重要的是，情绪对决策的影响可能会在更严重的焦虑和抑郁中产生更严重的后果，从而影响数百万人的福祉。建议的研究和预期的结果我的研究旨在了解记忆如何被用来指导我们的决定，这些决定如何被情绪所影响，以及大脑中潜在的快速神经过程。为了实现这一点，我的实验让健康的志愿者了解隐藏在迷宫中的不同奖励目标，并要求他们做出选择，是否追求这些目标。在日常生活中追求目标通常涉及多个步骤，例如，被教育项目录取，完成学位，最后找到一份好工作。在路上的每一个点，我们都面临着一些失败的机会。通过在我的实验中包含这样的风险，我可以看到参与者是如何平衡目标的回报与无法实现目标的风险的。这种平衡反映了人们的选择是乐观还是悲观，可能在个人之间差异很大。我的实验将测试这种可变性与性格和情绪差异之间的关系，并期望它与情绪低落和抑郁有关。进一步的研究还将探索如何创造短期的积极或消极情绪进一步推动人们走向更乐观或悲观的目标平衡。为了理解大脑中支持我们决策的潜在机制，我的实验也使用了脑成像。我使用脑磁图（MEG），这是一种非侵入性技术，可以让我们记录下数百个不同的记录传感器的快速神经活动，这些传感器被安排在一个类似头盔的设备中。最近，使用我们小组开发的新技术，我发现当一个人回忆起以前的事件时，大脑会非常迅速地回放这段经历。我正在进行的研究表明，同样的快速“回放”可能会支持我们在计划过程中通过重复实现目标的步骤来做出关于未来的决定。重要的是，我的发现继续延伸并转化到人类身上，这是最近在啮齿动物身上进行的一项令人兴奋的研究，研究对象是海马体中的神经元，海马体是记忆的关键区域。预期收益通过阐明大脑如何支持我们的决策，我的研究将为未来在焦虑和抑郁等情绪障碍方面的工作提供基础。我们的大型在线研究已经提供了抑郁症状的高度可变性，使我们能够检查情绪低落和决策之间的关系。我的研究发现也有可能为认知和行为治疗提供信息。例如，使用行为和脑成像测量，我可以描述个人对未来的低情绪相关悲观情绪的敏感性。对于脆弱的个体，我们可以制定心理干预策略，限制与情绪相关的悲观情绪。最后，影响很大一部分人口的压力，也可能影响决策中记忆的使用，我的研究可以为理解普遍存在的压力对行为的影响提供信息。

How does our past experience guide the decisions we make about the future? When planning to achieve a goal, we call upon relevant memories of our past. For example, our memories contain information about what happened to us, what may have stood in our way, and how good those events were. Our decisions are also often influenced by mood. For example, if you are in a low mood, you can more easily imagine your plans going wrong. Such a pessimistic outlook related to a low mood - or an optimistic outlook related to a positive mood - may then affect your motivation to pursue your goals. It is well known that our mood leads to the recollection of memories with a similar mood quality, but my research will for the first time look at how this memory bias affects our decisions. Importantly, the effect of mood on decision-making is likely to have more serious consequences in more severe anxiety and depression, which affect the well-being of millions of people.Proposed Research and Prospective OutcomesMy research aims to understand how memory is used to guide our decisions, how these decisions may be biased by mood, and the underlying fast neural processes in the brain. To pursue this, my experiments have healthy volunteers learn about different rewarding goals hidden in mazes, and asks them to make choices to pursue those goals or not. Pursuing a goal in everyday life usually involves multiple steps, for example, being accepted into an education program, completing the degree, and finally finding a good job. At each point along the way, we face some chance of failure. By including such a risk in my experiments, I can see how participants are balancing the rewards of a goal versus the risk that the goal will not be achieved. This balance, reflecting how optimistic or pessimistic people's choices are, is likely to vary greatly across individuals. My experiments will test how this variability may relate to differences in personality and mood, with an expectation that it will relate to low mood and depression. Further studies will also explore how creating a short-term positive or negative mood further pushes people toward more optimistic or pessimistic balancing of goals. To understand the underlying mechanisms in the brain that support our decisions, my experiments also use brain imaging. I use magnetoencephalography (MEG), a non-invasive technique that allows us to record very rapid neural activity from hundreds of different recording sensors arranged in a helmet-like device. Recently, using new techniques we developed in our group, I found that when one remembers a previous event, the brain very rapidly plays through the experience. My ongoing research suggests that the same rapid 'replay' may support the decisions we make about the future by playing through the steps to a goal during planning. Importantly, my findings continue to extend and translate to humans exciting recent research in rodents on replay of experiences in neurons in the hippocampus, a region critical for memory.Expected BenefitsBy illuminating how the brain supports our decision-making, my research will provide a foundation for future work in mood disorders such as anxiety and depression. Already, our large online studies will provide a high level of variability in depression symptoms, allowing us to examine the relationship between low mood and decision making. Discoveries from my research also have the potential to inform cognitive and behavioral therapy. For example, using behavior and brain imaging measures, I can characterize individual susceptibility to low-mood-related pessimism about the future. For vulnerable individuals, we can develop mental strategies for intervention, limiting mood-related pessimism. Finally, stress, which affects a large proportion of the population, is also likely to influence the use of memory in decisions, and my research can inform understanding of pervasive stress-related influences on behavior.