Abstract and experiential thinking differentially account for anomalous perception of reality in people with or...

repetitive thinking is often increased in various psychopathological conditions. However, evidence for its possible contribution to psychotic symptoms relies only on correlational analysis and has not been experimentally tested within the psychotic continuum. This research aims to examine whether repetitive thinking about a negative past experience using concrete versus abstract processing might modify the reporting of anomalous sensory experiences. 89 patients with schizophrenia and 89 matched controls were asked to reflect on their most negative Self-Defining Memory during a thirty-minute period. By means of a written script, half of the participants were instructed to remember thoughts, feelings and sensations associated with the event in an abstract mode, while the other half followed an equivalent script but with concrete questions. After induced concrete-experiential thinking, both controls and patients significantly reduced self-reported anomalous reality perception. However, participants in the induced abstract-analytical thinking condition increased anomalous experience, especially sensory experience from an unexplained source. Multigroup path analyses showed that involvement in abstract-analytical thinking during the task significantly mediated the relationship between pre-test and post-test anomalous perception scores, but only in the patient group. These results suggest that abstract thinking contributes to distorted sensory experiences. In contrast, training in a concrete processing mode of past experiences may be a useful tool to reduce subjective anomalous perceptions.