Figure 2.

Graphs depicting SCR responses in all experimental phases, with day 1 divided into fear acquisition and early and late extinction. Day 2 was comprised of early and late extinction recall in the safety context, followed by early and late fear renewal in the danger context. These data demonstrate that fear acquisition learning and extinction learning were intact for PTSD patients during day 1. However, PTSD patients exhibited a failure to effectively recall the extinction memory in the safety context and were also unable to effectively renew the fear memory in the danger context. Both of these effects on day 2 occurred during the early phases, before effective extinction learning again prevailed. The red boxes highlight the experimental phases of greatest interest, which were taken forward to fMRI analyses.