BACKGROUND AND OBJECTIVES: Research has documented the very brief exposure (VBE) effect: the reduction of phobic fear by continuous presentation of masked phobic pictures. In prior studies, phobic participants approached a live tarantula immediately after the masked stimuli were presented. This study tested the hypothesis that VBE would reduce phobic avoidance of the tarantula 24 h later. METHOD:86 spider-phobic participants were identified with a fear questionnaire and Behavioral Avoidance Test (BAT) with a live tarantula indicative of a DSM-IV diagnosis of Specific Phobia. One week later, they were randomly assigned in double-blind fashion to presentation of a continuous series of 25 trials of masked images of either spiders or flowers (33-ms each), i.e., to VBE or control exposure. The participants gave subjective distress ratings just before and after these exposures. Then they engaged in the BAT again either immediately thereafter or 24 h later to measure changes in avoidance of the tarantula. RESULTS: Masked images of spiders reduced avoidance of the tarantula both immediately after exposure and 24 h later without causing subjective distress. The effect sizes at these two time points did not significantly differ from each other. LIMITATIONS: We did not manipulate awareness of the spider images by presenting them unmasked to a third group. Conclusions about the effect of awareness of the stimuli cannot be drawn. CONCLUSIONS:VBE induces a process of fear reduction before phobic individuals engage in in vivo exposure, which is more distressing. Thus, VBE may help phobic-resistant individuals start treatment more gradually.
RCT Entities:
BACKGROUND AND OBJECTIVES: Research has documented the very brief exposure (VBE) effect: the reduction of phobic fear by continuous presentation of masked phobic pictures. In prior studies, phobic participants approached a live tarantula immediately after the masked stimuli were presented. This study tested the hypothesis that VBE would reduce phobic avoidance of the tarantula 24 h later. METHOD: 86 spider-phobic participants were identified with a fear questionnaire and Behavioral Avoidance Test (BAT) with a live tarantula indicative of a DSM-IV diagnosis of Specific Phobia. One week later, they were randomly assigned in double-blind fashion to presentation of a continuous series of 25 trials of masked images of either spiders or flowers (33-ms each), i.e., to VBE or control exposure. The participants gave subjective distress ratings just before and after these exposures. Then they engaged in the BAT again either immediately thereafter or 24 h later to measure changes in avoidance of the tarantula. RESULTS: Masked images of spiders reduced avoidance of the tarantula both immediately after exposure and 24 h later without causing subjective distress. The effect sizes at these two time points did not significantly differ from each other. LIMITATIONS: We did not manipulate awareness of the spider images by presenting them unmasked to a third group. Conclusions about the effect of awareness of the stimuli cannot be drawn. CONCLUSIONS: VBE induces a process of fear reduction before phobic individuals engage in in vivo exposure, which is more distressing. Thus, VBE may help phobic-resistant individuals start treatment more gradually.
Authors: Paul Siegel; Richard Warren; Zhishun Wang; Jie Yang; Don Cohen; Jason F Anderson; Lilly Murray; Bradley S Peterson Journal: Hum Brain Mapp Date: 2017-02-06 Impact factor: 5.038