Distinct Neural Signals Reveal a Dissociation between Storage of Individuated Items and Spatial Attention

At any given moment, there exists an overwhelming amount of information in our surroundings. Yet, only a subset of that information is relevant or critical to our current goals. Attention allows us to prioritize the selection of relevant information, thereby making that information accessible to higher order cognitive processes, like reasoning and decision-making. Meanwhile, working memory allows us to maintain and manipulate the selected information in a "mental workspace." In everyday life, attention and working memory are inextricably linked. For instance, mentally solving an arithmetic problem requires that we select, maintain, and manipulate its key elements. In this dissertation, I demonstrate that active maintenance of information relies on several subcomponents whose operations are tracked by distinct neural signals. In Chapter 1, I demonstrate that there exists a generalizable human signature of attention that tracks the selection and maintenance of spatial positions in mind. In Chapter 2, I provide evidence that neural activity tracking items based on their spatial positions can be dissociated from activity tracking the number of individuated items. Finally, Chapter 3 proposes that signals tracking the number of items in mind are instead indexing the product of a more fundamental cognitive operation. Namely, I provide evidence that this neural activity represents spatiotemporal "pointers" that enable the continuous tracking of items without necessarily containing information about the items themselves. Together, the current work highlights that neural activity related to attention and working memory reflects parallel but distinct processes that jointly contribute to successful behavior.