Internal States Influence Learning Behavior and Structure Event Memory

Internal states, such as one’s emotions, goals, and motivations, have profound impacts on how people perceive the world, interact with their environment, and remember their experiences. Understanding how internal states influence learning behaviors and episodic memory remains a critical challenge for the field of psychology and neuroscience. In this dissertation, I present three empirical studies that approach this challenge by examining how shifts in internal states influence event segmentation and memory organization, and how sustained internal states shape choices during reward learning and memory formation. In the first study, I tested whether shifts in internal goal states, as defined by switching between different task rules, created event boundaries in memory. Across five behavioral experiments, I found that both cued and voluntary task switching led to temporal memory effects that characterize event segmentation, and these effects cannot be attributed to perceptual changes or changes in task difficulty. These results demonstrate that shifts in internal goal states, even when they are generated without any external cue as in the case of voluntary task switching, organize event memory. In the second study, I further explored the role of internal goal states in episodic memory and found that transient increases in attention do not impact memory for temporal relationships between items despite robust boost to recognition memory for individual items encoded during behaviorally relevant moments. These results show that fluctuations in attention without updating internal goal states are insufficient to influence temporal organization of memory. In the third study, I used computational modeling and neuroimaging methods to investigate how sustained motivational states that focus on proximal and distal goals respectively influence learning behaviors and memory outcomes in a reinforcement learning environment. I found that sustained motivational states shifted the balance between reward-maximizing exploitation behavior and uncertainty-directed exploration behavior during reward learning. Furthermore, successful memory formation was supported by distinct neural routes for participants motivated by an urgent performance goal and those motivated by a future learning goal. These results suggest that different sustained internal states under the same reward learning environment can lead to divergent behavioral outcomes and differential neural mechanisms for memory encoding. Collectively, the work presented in this dissertation demonstrates the importance of internal states in learning and memory processes and furthers our understanding of how goals and motivations shape the human experience.