CAREER:Functional contributions of lateral parietal cortex to episodic memory

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

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.