Does a visual perceptual disturbance characterize trauma-related anxiety syndromes?

The i-test was developed to assess the visual-perceptual disturbances (VPDs) frequently reported by anxious patients. Persons with the disturbance report a specific abnormal illusion of movement when they maintain a fixed gaze at the i-test stimulus. Base rates for positive responses to the i-test and for reports of a "recurrent specific memory" (RSM) of a fear experience were obtained in psychiatric outpatient (n = 301) and community (n = 128) samples. In each case, approximately one fifth of participants had a positive response to the i-test and one fifth of participants reported an RSM of fear. A positive response to the i-test is observed in women more frequently than in men. Among psychiatric patients, approximately 90% of patients who report one symptom also report the other symptom; among community members, the concordance rate is approximately 33%. When psychiatric patients with both an abnormal illusion of movement response and an RSM of trauma are treated with eye movement desensitization, both symptoms are removed in 70% of cases; when these patients undergo some other form of treatment, both symptoms are removed in 30% of cases. These results indicate that the i-test is an effective way of identifying VPDs associated with psychopathologic conditions; the association between the abnormal illusion of movement and reports of recurrent specific memories of fear experiences suggests that the VPD may be a marker of traumatic stress syndromes.