UCLA

The human mind is rarely, if ever, inert. We are constantly barraged with external stimuli, but also experience a rich inner life of recollections, planning, and pondering which occur spontaneously throughout our waking hours. In this dissertation, I have aimed to investigate the cognitive mechanisms underpinning the segmentation, differentiation, and representation of event memories, acknowledging the ongoing dynamics of internal and external attention. I have taken as a paradigm the dynamic and flexible interplay between internal and external attention as a critical factor in memory encoding and organization. In Chapter 2, I present findings from a series of experiments which demonstrate the ways in which fluctuations in on-going attention (i.e. mind-wandering) act upon the later recollection of temporal order. In a similar vein Chapter 3 demonstrates how hierarchical contexts which change at different rates instrumentally decrement or benefit later recollection of temporal order memory. Building upon the idea of hierarchical and dynamic representations, in Chapter 4 I present a theoretical account of how attention and mind wandering may play an instrumental role in the alteration of memory organization and recollection in individuals with depression. In this chapter, I critique the canonical theory of overgeneral memory in depression and instead underscore basic long-term memory and attention processes to explain how memories may become blunted in mood disorders. Finally, in Chapter 5, I test this hypothesis by investigating how memory similarity may be derived from semantic representations to demonstrate how personal memory organization is changed in individuals with depression compared to healthy controls. These chapters highlight the theoretical and methodological advancements that have been and should continue to be made in the course of this dissertation.