Temporal dynamics of trauma memory persistence

Abstract

Traumatic events lead to distressing memories, but such memories are made all the worse when they intrude to mind unbidden and recurrently. Intrusive memories are a hallmark of several mental health disorders including posttraumatic stress disorder (PTSD) and can persist for years. Critically, the reduction of intrusive memories provides a treatment target. While cognitive models for psychological trauma exist, these lack formal quantitative structure and robust empirical validation. Here we develop a mechanistically-driven, quantitative framework to extend understanding of the temporal dynamic processes of trauma memory. We show how the marginal gains of interventions for intrusive memories can be enhanced as key properties of the intervention vary. Validating the framework against empirical data highlights that while emerging interventions to reduce occurrence of intrusive memories can be effective, counter-intuitively, maintaining these memories in a sufficiently reactivated state is essential for preventing their persistence. Author SummaryIntrusive memories and flashbacks after trauma are prominent in several mental disorders. Quantifying these intrusions is the aim of the current study. While many conceptual models for trauma memory exist, none provide a mechanistic framework for validating experimental or clinical evidence. Our approach is to develop a probabilistic description of memory mechanisms to link to the broader goals of trauma treatment. Analysis shows how critical attributes of the framework such as intervention strength and reminder strength determine success in managing intrusive memories. Validation with empirical data shows how the framework can be parameterized and predictions evaluated against observed outcomes. In this way neural mechanisms associated with memory can be combined with broader cognitive processes.