Reinstatement of fear in humans: autonomic and experiential responses in a differential conditioning paradigm.

The present study investigated reinstatement of fear in humans using an aversive differential conditioning paradigm. Two neutral human face pictures were presented during habituation, acquisition, extinction, and postreinstatement phases. One picture served as a conditioned stimulus (CS) reinforced by an unconditioned stimulus (US) in the form of electrical stimulation (CS+) and the second picture as a control stimulus that was never reinforced (CS-). The prediction that in a reinstatement manipulation a previously extinguished fear response in humans can be reinstated in a reinstatement group by the mere presentation of three unpredicted electrical stimulations (USs) was tested. Participants in the control group were not exposed to unpredicted USs and no reinstatement effect was expected. Outcome measures included subjective US expectancy ratings and skin conductance responses. Results showed non-selective return of the fear response due to fear recovery associated with both CSs (CS+/CS-) in the reinstatement group. Unexpected fear recovery was observed for both CSs (CS+/CS-) in control participants. Results are discussed with respect to context conditioning, fear generalisation, and anxiety-related cognitive mechanisms underlying fear recovery after extinction.

One-session computer-based exposure treatment for spider-fearful individuals--efficacy of a minimal self-help intervention in a randomised controlled trial.

Computer-based self-help treatments have been proposed to provide greater access to treatment while requiring minimum input from a therapist. The authors employed a randomised controlled trial to investigate the efficacy of one-session computer-based exposure (CBE) as a self-help treatment for spider-fearful individuals. Spider-fearful participants in a CBE group underwent one 27-min session of standardised exposure to nine fear-eliciting spider pictures. Treatment outcome was compared to spider-fearful control participants exposed to nine neutral pictures. Fear reduction was quantified on a subjective level by the Fear of Spiders Questionnaire (FSQ) and complemented with a behavioural approach test (BAT). Results demonstrate that compared to control participants, CBE participants showed greater fear reduction from pre- to posttreatment on both the subjective level (FSQ) and the behavioural level (BAT). Moreover, in contrast to the control group, the obtained subjective fear reduction effect remained stable in the CBE group at 1-month follow-up. These findings highlight the role of computer-based self-help as a minimal but effective intervention to reduce fear of spiders.