Eye-Movement Intervention Enhances Extinction via Amygdala Deactivation

J Neurosci. 2018 Oct 3;38(40):8694-8706. doi: 10.1523/JNEUROSCI.0703-18.2018. Epub 2018 Sep 4.

Abstract

Improving extinction learning is essential to optimize psychotherapy for persistent fear-related disorders. In two independent studies (both n = 24), we found that goal-directed eye movements activate a dorsal frontoparietal network and transiently deactivate the amygdala (η p 2 = 0.17). Connectivity analyses revealed that this downregulation potentially engages a ventromedial prefrontal pathway known to be involved in cognitive regulation of emotion. Critically, when eye movements followed memory reactivation during extinction learning, it reduced spontaneous fear recovery 24 h later (η p 2 = 0.21). Stronger amygdala deactivation furthermore predicted a stronger reduction in subsequent fear recovery after reinstatement (r = 0.39). In conclusion, we show that extinction learning can be improved with a noninvasive eye-movement intervention that triggers a transient suppression of the amygdala. Our finding that another task which taxes working memory leads to a similar amygdala suppression furthermore indicates that this effect is likely not specific to eye movements, which is in line with a large body of behavioral studies. This study contributes to the understanding of a widely used treatment for traumatic symptoms by providing a parsimonious account for how working-memory tasks and goal-directed eye movements can enhance extinction-based psychotherapy, namely through neural circuits (e.g., amygdala deactivation) similar to those that support cognitive control of emotion.SIGNIFICANCE STATEMENT Fear-related disorders represent a significant burden on individual sufferers and society. There is a high need to optimize treatment, in particular via noninvasive means. One potentially effective intervention is execution of eye movements following trauma recall. However, a neurobiological understanding of how eye movements reduce traumatic symptoms is lacking. We demonstrate that goal-directed eye-movements, like working-memory tasks, deactivate the amygdala, the core neural substrate of fear learning. Effective connectivity analyses revealed amygdala deactivation potentially engaged dorsolateral and ventromedial prefrontal pathways. When applied during safety learning, this deactivation predicts a reduction in later fear recovery. These findings provide a parsimonious and mechanistic account of how behavioral manipulations taxing working memory and suppressing amygdala activity can alter retention of emotional memories.

Keywords: Pavlovian fear conditioning; amygdala; cognitive control; extinction learning; eye movement desensitization and reprocessing (EMDR); functional MRI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amygdala / physiology*
  • Brain Mapping
  • Conditioning, Classical
  • Electroshock
  • Extinction, Psychological / physiology*
  • Eye Movements*
  • Fear / physiology*
  • Female
  • Frontal Lobe / physiology
  • Galvanic Skin Response
  • Goals
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Memory, Short-Term
  • Neural Pathways / physiology
  • Parietal Lobe / physiology
  • Young Adult