Mapping Control Densely: Using a Novel Neuroimaging Approach to Explore the Neural Organization of Cognitive Control

Abstract

Cognitive control, the ability to act on internally represented goals, is an essential cognitive function. Decades of neuroimaging research have been devoted to elucidating its neural underpinnings, but there is still a lot we do not understand. Limitations of traditional neuroimaging approaches may have slowed progress in obtaining a detailed understanding of cognitive control. Recent person-specific and precision neuroimaging approaches have attempted to address these limitations and have successfully revealed previously unseen details of the brain’s neural architecture. The current dissertation aims to review these findings and explore the neural organization of cognitive control using such a person-specific approach to neuroimaging. Chapter 2 consists of a literature review detailing the limitations of traditional neuroimaging approaches and how person-specific and precision approaches attempt to address these limitations. It reviews the literature in this new field in depth, including discussions of the potential limitations of these new approaches as well as considerations for future research. Chapters 3 through 5 involve the creation of a dense neuroimaging dataset and its use in exploring the neural organization of cognitive control. Two individuals were scanned for approximately 12 hours each as they completed 22 different tasks twice on separate days. Then, in chapter 3, patterns of neural activity from these tasks were compared in order to assess whether patterns of neural activity would be more similar to each other when they came from the same person than when they came from different people, and whether the similarity of these patterns would change with the different tasks. Results revealed that patterns of neural activity during cognitive control tasks are more similar within individuals than across, and that these patterns change significantly with task. These findings suggest that patterns of neural activity from cognitive control tasks are person-specific and reliable, and that some tasks are better suited for individual differences research than others. Chapters 4 and 5 then seek to explore the neural organization of cognitive control in relation to three influential theoretical frameworks—one emphasizing control processes, one emphasizing task sets, and one emphasizing a combination of the two. Chapter 4 uses exploratory factor analysis to identify major sources of variation in control-related neural activity in several regions associated with cognitive control. Chapter 5 then uses confirmatory factor analysis to directly compare models based on the three frameworks in order to test which (if any) best reflected the neural organization of cognitive control in individuals. The results of both chapters were most consistent with frameworks emphasizing a combination of process- and task set-specific information, such as might be proposed by theories like flexible hub theory. In Chapter 4, we found that latent factors were associated with both control processes and specific task sets, and in chapter 5, we found that the combination framework model often provided the best fit to the data. Together, these findings highlight the potential value of this novel dense neuroimaging approach, the benefits of using large task batteries to study cognitive function, and the utility of this novel method to characterize the neural organization of cognitive control.