Neural Systems Underlying the Suppression of Unwanted Memories

TLDR

Repression, the exclusion of unwanted memories from awareness, was first proposed by Freud, but the neural mechanisms underlying this process remain unclear. The study aimed to identify the neural systems that suppress unwanted memories. Functional MRI was used to map brain activity during suppression of unwanted memories. The results showed that suppressing unwanted memories engaged the dorsolateral prefrontal cortex, suppressed hippocampal activity, impaired memory retention, and that prefrontal and right hippocampal activations predicted the extent of forgetting, confirming an active forgetting process and providing a neurobiological model.

Abstract

Over a century ago, Freud proposed that unwanted memories can be excluded from awareness, a process called repression. It is unknown, however, how repression occurs in the brain. We used functional magnetic resonance imaging to identify the neural systems involved in keeping unwanted memories out of awareness. Controlling unwanted memories was associated with increased dorsolateral prefrontal activation, reduced hippocampal activation, and impaired retention of those memories. Both prefrontal cortical and right hippocampal activations predicted the magnitude of forgetting. These results confirm the existence of an active forgetting process and establish a neurobiological model for guiding inquiry into motivated forgetting.