Here we ask whether it is possible to reduce the intrusiveness of an unwanted memory while avoiding any requirement for people to consciously reexperience it.

Reponses to aversive content can lead participants to prematurely terminate therapy and also involve additional risks to patients 3, 4. Actual or imaginal re-exposure, although effective in reducing symptoms, can be aversive to patients. For instance, a widely used therapy for PTSD, exposure therapy, involves gradually confronting cues related to the traumatic event and a second, the eye movement desensitization and reprocessing (EMDR) treatment approach requires that patients hold a mental image of the traumatic event in mind while visually tracking a bilateral stimulus 2. Treatments on these symptoms often emphasize gradual re-exposure to the major stressors. Recurrent intrusive memories and ruminations are key symptoms in a range of psychiatric conditions, including post-traumatic stress disorder (PTSD), acute stress disorder, and obsessive-compulsive disorder 1. Combining the amnesic shadow with subliminal reactivation may offer a new approach to voluntary forgetting that bypasses the unpleasantness in conscious exposure to unwanted memories. Critically, whereas unconscious forgetting occurs on these affective memories, the amnesic shadow itself is induced by conscious suppression of unrelated and benign neutral memories, avoiding conscious re-exposure of unwelcome content. Building on this mechanism, here we successfully disrupt retention of unpleasant memories by subliminally reactivating them within this amnesic shadow. Disrupting hippocampal function through retrieval suppression induces an amnesic shadow that impairs the encoding and stabilization of unrelated memories that are activated near in time to people’s effort to suppress retrieval. But it is unclear whether awareness of aversive content is necessary for effective voluntary forgetting.

Processes that might facilitate the forgetting of unwanted experiences typically require the actual or imagined re-exposure to reminders of the event, which is aversive and carries risks to people.

Another word for memories