Safety behaviours preserve threat beliefs: Protection from extinction of human fear conditioning by an avoidance response.

A laboratory autonomic conditioning procedure was used to establish fear conditioning in human participants by pairing neutral stimuli with electric shock. Participants were also trained to make a button-press response to avoid shock. A target fear stimulus was then extinguished by presenting it without shock. The experimental group was given the opportunity to make the avoidance response during extinction whereas the control group was not. When the fear stimulus was tested without the response available, the control group showed normal extinction of both shock expectancy ratings and skin conductance responses, but the experimental group showed "protection from extinction": they continued to give high expectancy ratings and strong skin conductance responses. We interpret this effect as analogous to the role of within-situation safety behaviours in preserving threat beliefs during exposure therapy for anxiety disorders. The results support a cognitive account of learning and anxiety. The procedure provides a potential laboratory model for further examination of the cognitive and neural mechanisms underlying anxiety and its reduction.