CCN talk: October 18, 2024
Structural and functional architecture of the prefrontal cortex for working memory
The prefrontal cortex (PFC) is consistently active during working memory (WM) and other cognitive tasks, but there is debate regarding its specific role in support of WM behavior across studies, scales, and species. In this talk, I will detail how a precision neuroimaging approach can help bridge discrepant findings regarding the nature of PFC function. First, I will showcase how a unique, longitudinal sampling of WM representations across long-term learning uncovers PFC activity patterns more typically found in non-human primate electrophysiology studies vs. human neuroimaging. To do this, three human participants each completed over 20 sessions of functional MRI (fMRI) along with at-home training over three months. During this time, participants repeatedly performed a WM and a sequence learning task with complex fractal stimuli. Across the course of training, both stimulus-specific and categorical WM representations emerged across different PFC areas. Second, I will show how WM representations are transformed from a stimulus-related code in visual areas to a goal-related code in PFC based on unique combinations of stimuli, rules, and task demands. Importantly, considering task goals in this way can help reveal the differential contributions of cortical areas to flexible WM behavior. Finally, I will detail how careful identification of individual-level anatomical features in PFC reveals relationships between neuroanatomy, functioning, and cognition - helping us to map the “cognitive globe” of the PFC. Collectively, the tools and lessons of individual-level functioning and neuroanatomy allow us to characterize robust brain-behavior relationships that advance our understanding of WM and related cognitive processes.