Eye-movement intervention enhances extinction via amygdala deactivation

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 fronto-parietal network and transiently deactivate the amygdala. Connectivity analyses revealed this down-regulation engages a ventromedial prefrontal pathway known to be involved in cognitive regulation of emotion. Critically, when eye movements followed memory reactivation during extinction learning, this reduced spontaneous fear recovery 24 hours later. Stronger amygdala deactivation furthermore predicted a stronger reduction in subsequent fear recovery after reinstatement. In conclusion, we show that extinction learning can be improved with a non-invasive 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 similar to those that support cognitive control of emotion. Significant statement Fear-related disorders represent a significant burden on individual sufferers and society. There is a high need to optimize treatment, in particular via non-invasive means. One potentially effective intervention is execution of eye movements following trauma recall. However, a neurobiological understanding of how eye movements can 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 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 suppress amygdala activity can alter retention of emotional memories.