background Deficient fear conditioning can lead to maladaptive contextual anxiety. This may provide an experimental model for the development of generalised anxiety.
aim To explore two different mechanisms that lead to contextual anxiety: failure to learn predictors of threat and failure to inhibit contextual fear even though these predictors are learned.
method Healthy young adults participated in a conditioning experiment in which virtual reality software provided two distinct contexts. In one of these contexts, a predictive cue (lights on) preceded occasional shock reinforcements. Subjective measures of shock expectancy indexed contingency learning. Subjective measures of fearfulness and physiological measures (fear-potentiated startle, skin conductance responses) reflected levels of conditioned responses. Study 1 (n = 57) focused on individual differences in learning the cue contingency. Study 2 (n = 21) focused on individual differences in the ability to inhibit fear after learning predictors of threat. This design started with conditioning to the context only, followed by introduction of the predictive cue and a specific instruction regarding cue-shock contingency.
results In study 1, 30% of participants failed to learn the cue contingency and displayed greatly enhanced levels of fear in the threat context compared to participants who learned the contingency. The group that learned, distinguished from those who did not in superior attentional control scores. Of the participants who learned the cue contingency, 35% remained fearful in the absence of the cue as indexed by shock expectancy, subjective fear and fear-potentiated startle. Study 2 established that the ability to inhibit fear to a previously conditioned context was significantly correlated with trait anxiety questionnaire-scores.
conclusion The results indicate two different avenues toward increased contextual fear. Superior attentional control may facilitate learning predictors, which potentially allows protection against contextual anxiety. Yet, after predictors of threat have been identified, inhibition of fear in the absence of these predictors is impaired in those with high trait anxiety.