Linking sensory uncertainty with motivation and memory

摘要： 处理信息以减少不确定性是大脑的关键作用。新的证据表明，在 除了使用给予它们的信息之外，动物还积极地寻求获得关于未来的信息。 奖励或语义（琐事）问题。信息需求（ID）即使是非工具性的，也是稳健的 （不能被利用来增加奖励收益）。此外，非工具性ID激活了奖励敏感的 多巴胺能中脑和增强记忆，这表明不确定性，独立于奖励收益，是一个 决策和认知功能的动机来源。然而，人们对神经系统的了解甚少。 调节这些不确定性影响的机制。我将通过设计一个新任务来解决这个问题， 测量知觉ID，并允许我检查感觉不确定性的信号如何与 动机和记忆。我识别出了视觉图像--“texforms”--可以可靠地激活人类的腹侧颞叶 并且可以以受控的方式扭曲，以参数化地操纵关于 有生命/无生命刺激类别。其次，我将使用生成模型来解码一次又一次的感觉 VTC中刺激诱发的多体素活动的不确定性。最后，我展示了初步证据， 知觉ID（揭示模糊图像身份的愿望）与以下行为报告有关： 信心（不确定性的代理）。在目标1中，我将研究VTC中的感觉不确定性 与中脑活动直接相关或由对置信度的单变量响应介导（例如， 背侧前扣带皮层）。在目标2中，我将研究职业训练局的不确定性调节 海马体并产生与ID相关的记忆增强。此外，我将探讨的可能性， 不同的网络相互作用介导了ID对即时记忆和延迟记忆的影响。总之， 将带来重要的新见解的途径，通过多变量和单变量的信号， 不确定性激发了减少不确定性和影响记忆的行为。此外，这些结果将扩大我们的 了解在情绪和焦虑障碍中产生不确定性的适应不良效应的途径。

Abstract: Processing information that reduces uncertainty is a key role of the brain. Emerging evidence shows that, in addition to using information that is given to them, animals actively seek to obtain information about future rewards or semantic (trivia) questions. Information demand (ID) is robust even when it is non-instrumental (cannot be exploited to increase reward gains). Moreover, non-instrumental ID activates the reward-sensitive dopaminergic midbrain and enhances memory, suggesting that uncertainty, independently of reward gains, is a source of motivation for decision making and cognitive function. However, little is known about the neural mechanisms mediating these effects of uncertainty. I will address this question by designing a new task that measures perceptual ID and allows me to examine how signals of sensory uncertainty relate to those of motivation and memory. I identified visual images – “texforms” – that reliably activate human ventral temporal cortex (VTC) and can be distorted in a controlled fashion to parametrically manipulate the uncertainty about animate/ inanimate stimulus categories. Second, I will use a generative model to decode trial-by-trial sensory uncertainty from stimulus-evoked multi-voxel activity in the VTC. Finally, I show preliminary evidence that perceptual ID (the desire to reveal the identity of an ambiguous image) is related to behavioral reports of confidence (a proxy of uncertainty). In Aim 1, I will examine the hypothesis that sensory uncertainty in VTC relates to midbrain activity either directly or mediated by univariate responses to confidence (such as those in the dorsal anterior cingulate cortex). In Aim 2, I will examine the hypothesis that VTC uncertainty modulates the hippocampus and generates ID-related memory enhancements. Furthermore, I will explore the possibility that distinct network interactions mediate the effect of ID on immediate and delayed memory. Together, the findings will bring significant new insights into the pathways through which multivariate and univariate signals of uncertainty motivate actions that reduce uncertainty and affect memory. In addition, the results will expand our understanding of pathways that produce maladaptive effects of uncertainty in disorders of mood and anxiety.