A cognitively demanding working-memory intervention enhances extinction

Improving extinction learning has the potential to optimize psychotherapy for persistent anxiety-related disorders. Recent findings show that extinction learning can be improved with a cognitively demanding eye-movement intervention. It is, however, unclear whether [1] any cognitively-demanding task can enhance extinction, or whether it is limited to eye movements, and [2] the effectiveness of such an intervention can be enhanced by increasing cognitive load. Participants (n = 102, n = 75 included in the final sample) completed a Pavlovian threat conditioning paradigm across two days. One group underwent standard extinction (Control), a second group underwent extinction paired with a 1-back working memory task (Low-Load), and a third group underwent extinction paired with a 2-back working memory task (High-Load). We found that the conditioned response during extinction was reduced for both the Low-Load and the High-Load groups compared to the Control group. This reduction persisted during recovery the following day when no working memory task was executed. Finally, we found that within the High-Load group, participants with lower accuracy scores on the 2-back task (i.e., for who the task was more difficult) had a stronger reduction in the conditioned response. We did not observe this relationship within the Low-Load group. Our findings suggest that cognitive load induced by a working memory intervention embedded during extinction reduces persistent threat responses.