Date of Award

Fall 1-1-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Psychology

First Advisor

Cannon, Tyrone

Abstract

Psychosis is characterized by salient conflicts between reality and one’s experience of it, but the cognitive processes that give rise to these conflicts are not fully characterized. Similar conflicts are felt by many members of the general population, albeit to a lesser extent. By studying these experiences in a subclinical context (i.e., psychosis proneness), we stand to gain new insights about the cognitive processes that support psychotic-like thought across a continuum. In this dissertation, I propose an updated cognitive model that predicts a link between the positive and disorganized symptoms of psychosis and distinct disruptions in memory and learning. More specifically, I suggest that these symptoms may be closely related to disruptions in the organization of experiences along the dimension of time. To test this model, this dissertation employs a series of novel behavioral tasks that explicitly model temporal information in memory and learning within a population enriched for psychosis proneness (i.e., online workers). Study 1 validates a method for measuring the directionality of errors in temporal memory, linking positive and disorganized symptoms for the first time to a hyper-recency bias in memory. Study 2 extends this paradigm to indicate a similar hyper-recency bias among those who experience déjà vu more intensely and provides evidence that these individuals show an attenuated ability to inhibit the retrieval of context-irrelevant memories. Finally, Study 3 explores the dynamics of deviancy detection as it unfolds over time, revealing that those high in psychosis proneness are especially likely to fail to detect change when it truly occurs and are less influenced by prior experience when judging change on a current trial. Together, these studies support an updated model of memory dysfunction in psychosis proneness which is characterized by 1) reduced temporal organization of episodic memory, such that recognized stimuli are systematically judged to have occurred more recently than they actually did, 2) a reduced ability to inhibit the retrieval of contextually irrelevant memories, and 3) under-active detection of deviancy, subserved by a reduced influence of past experience on current processing. Together, these breakdowns in the temporal dynamics of memory and learning may represent an eroding of the dams that normally constrain retrieval processes, allowing the salient intrusion of mental content that is only weakly relevant to the current context. In this way, this dissertation contributes to our understanding of the cognitive processes through which one’s experience of reality can become decoupled from consensus, highlighting a path forward for future interventions targeting the cognitive, positive, and/or disorganized symptoms of psychotic illness.

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