CAREER:Functional contributions of lateral parietal cortex to episodic memory

人类记忆的一个显著特征是，人们可以通过将这些经历带回脑海中来生动地重新体验过去的事件。在过去的二十年里，神经成像研究一直发现，顶叶皮质在这种重新体验过去的能力中发挥着作用。然而，顶叶皮质对人类记忆的具体贡献方式仍然是一个有很大争议的话题。在这一职业奖项的支持下，Kuhl博士将结合使用功能磁共振成像(FMRI)、脑电(EEG)和先进的统计学方法来确定记忆是如何在顶叶皮质的活动分布模式中编码的。研究将确定记忆的顶叶表征是如何由行为目标塑造的，这些表征如何随着时间的推移而演变，以及在记忆行为期间，顶叶皮质如何与其他大脑区域相互作用。这项研究的最终结果将是对顶叶皮质在记忆中的作用的计算理解。这将为人类记忆的理论提供关键的信息，并将与理解记忆功能如何以及为什么受损有关。此外，这些研究的研究结果和分析方法将被用于为当地一所中学生成基于项目的新颖数学课程，有助于提高人们对STEM职业的兴趣和认识。在这个项目中，人类功能磁共振研究将被用来确定记忆表征是如何在顶叶皮质活动的分布模式中编码的。前向编码模型将被用来预测给定刺激将在顶叶皮质引发的活动模式。这些模型将基于该刺激的语义属性(即，刺激内容)和该刺激的“记忆状态”(即，该刺激是否从过去的经验中被记住)。然后，库尔博士将测试自上而下的行为目标对顶叶记忆表征的影响。据预测，与感觉皮层中的表征相比，顶叶表征对行为目标更敏感。这一预测是由一种理论观点推动的，即顶叶皮质作为感觉皮质和前额叶皮质之间的界面。与这一预测相关的是，脑电解码研究将跟踪顶叶皮质出现记忆表征的时间。预计顶叶表征将在时间上落后于感觉区域的表征，并将表现出与导致行为决定的前额表征的一致性。最重要的目标是开发一种新的理论解释，说明顶叶皮质如何通过内部计算和与其他大脑区域的相互作用来促进记忆。这些研究活动还将提供关于顶叶皮质如何在更广泛的认知过程中做出贡献的见解。

It is a remarkable feature of human memory that people can vividly re-experience events from the past by bringing these experiences back to mind on command. Over the past two decades, neuroimaging studies have consistently found that the parietal cortex plays a role in this ability to re-experience the past. However, the specific way in which parietal cortex contributes to human memory remains a topic of substantial debate. With the support of this CAREER award, Dr. Kuhl will use a combination of functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and advanced statistical approaches to determine how memories are encoded in distributed patterns of activity in parietal cortex. Studies will determine how parietal representations of memories are shaped by behavioral goals, how these representations evolve over time, and how parietal cortex interacts with other brain regions during acts of remembering. The research will culminate in a computational understanding of the role of parietal cortex in memory. This will critically inform theories of human memory and will be relevant to understanding how and why memory function is impaired. Additionally, research findings and analysis approaches from these studies will be used to generate a novel, project-based math curriculum for a local middle school, helping to raise interest in and awareness of STEM careers. In this project, Human fMRI studies will be used to identify how memory representations are encoded in distributed patterns of activity in parietal cortex. Forward encoding models will be used to predict the activity pattern that a given stimulus will elicit in parietal cortex. These models will be based on the semantic properties of that stimulus (i.e., stimulus content) and the "memory status" of that stimulus (i.e., whether the stimulus is remembered from a past experience). Dr. Kuhl will then test how parietal memory representations are influenced by top-down behavioral goals. It is predicted that compared to representations in sensory cortex, parietal representations will be more sensitive to behavioral goals. This prediction is motivated by a theoretical perspective wherein parietal cortex functions as an interface between sensory cortex and prefrontal cortex. Related to this prediction, EEG decoding studies will track the timing with which memory representations emerge in parietal cortex. It is expected that parietal representations will temporally lag those in sensory areas, and will exhibit coherence with prefrontal representations leading up to behavioral decisions. The overarching goal is to develop a new theoretical account of how parietal cortex contributes to memory via internal computations and interactions with other brain regions. The research activities will also provide insight into how parietal cortex contributes to cognitive processes more generally.