Introduction: Investigations have suggested that people with an obsessive-compulsive disorder have an impaired processing of threatening information and attentional bias toward such stimuli. Meanwhile, according to the important role of disgusting stimuli in the persistence of obsessive-compulsive disorder, more research is needed to evaluate the visual attention of these people with regards to the disgusting stimuli. The choice of proper disgusting pictures for the assessment of visual attentional processes in obsessive-compulsive disorder is yet to be addressed. This research aimed to develop and validate a test serving the above purpose using disgusting and matched neutral pictures. Method: To this end, 113 paired disgusting pictures which were matched with neutral ones in terms of size, resolution, complexity and background, were selected through a thorough search in the web. Assessment of the external validity of the pictures was performed by five independent psychiatrists and clinical psychologists. As such, 73 neutral and 80 disgusting pictures which met the experts’ criteria were selected. To assess the internal validity, pictures were submitted to 20 subjects with obsessive-compulsive disorder (12 cases with washing rituals and 8 without). Subjects were then asked to evaluate the pictures based on the four dimensions including, valence, arousal, disgusting and threatening load from 1 (lowest) to 9 (highest).
Results: The results of discriminant validity evaluation and reliability of measures, indicated that the pictures which were selected in this study as disgusting-neutral pictures are sufficiently valid and reliable.
Conclusion: Pictures which were selected in this study as disgusting-neutral pictures could be suitable for the assessment of visual attention processes in patients with obsessive-compulsive disorder and washing rituals.