Figure 4.

Remission rates under various extinction manipulations. Group remission rate is shown as a dark bar. Confidence intervals are shown in blue. Remission is defined as less than 37.5% freezing following reinstatement. Note that the percentages here refer to proportion of subjects achieving remission, not freezing scores. Under standard extinction training with saline injections, the rate of long-term remission was only 18%, 95% CI [4%, 35%]. The rate of remission almost doubled with either the addition of a retrieval trial prior to extinction (33%, 95% CI [13%, 54%]) or MB injection after extinction (35%, 95% CI [17%, 55%]). When the manipulations are combined, 50% of the subjects achieve remission status, 95% CI [27%, 68%], demonstrating significant superiority over standard extinction with saline. Ext, Extinction; MB, Methylene Blue; Ret, Retrieval. (Online version in colour.)