Reinstatement of contextual anxiety in humans: Effects of state anxiety.

After successful extinction of conditioned fear, the presentation of an unsignaled unconditioned stimulus (US) leads to return of fear, thus, the previously extinguished conditioned stimulus (CS) triggers fear responses again. Human studies on such reinstatement processes are still inconclusive. Some revealed a general increase of fear reactions, both to the fear (CS+) and the safety stimulus (CS-), whereas other studies discovered a differential return of fear with enhanced fear responses to the CS+ only. Moreover, we know little about reinstatement of contextual anxiety, a state of general anxious apprehension and chronic worry. Therefore, the present study investigated reinstatement of contextual anxiety with an ecological valid virtual reality (VR) design. Additionally, we examined whether the current state anxiety might modulate the reinstatement of contextual anxiety. To this end, two groups underwent context conditioning on Day 1, i.e., one context (CXT+) became paired with unpredictable USs, but not the other context (CXT-), and an extinction training on Day 2. On Day 3 a reinstatement test was conducted, i.e., one group (reinstatement group, n=21) received one unsignaled US before testing, whereas the control group (n=21) did not. Only the reinstatement group showed a differential return of contextual anxiety as measured by fear-potentiated startle and anxiety ratings. Interestingly, the reinstatement of fear-potentiated startle was additionally influenced by state anxiety. Conclusively, an anxious state before an unsignaled aversive event might favor a return of contextual anxiety.