Resumo

A variety of studies involving schizophrenic patients have shown the occurrence of severe disabilities related to perception and cognition. Most diagnostics rely on alterations that reveal faulty reasoning. In this study we argue for another approach to assess this disease, since we assume that prior to a cognitive disorganization, perceptual abnormalities must take place. Objectives Why not detect and treat altered perception prior to faulty cognition? The difficulty rests in identifying a myriad of small changes within a perceptual mosaic of relevant and irrelevant stimuli. Our group has been studying ways of evaluating altered visual form perception in schizophrenic patients using paintings by Salvador Dalí. Method We conducted two studies with schizophrenic patients. Sixty (60) volunteers participated in the first study and other 44 were involved in the second study, all presenting similar backgrounds and age ranges, and equally divided into control group, CG and experimental group, EG in both studies. The schizophrenic patients attended outpatients clinics and were all medicated, using either typical and/or atypical antipsychotics. Twenty four (24) paintings by Dalí were selected based on the requirement that a great diversity of forms and large disparities in size had to be present. Paintings were photographed and printed in 10 x 15 cm photo cards surrounded by a 3.0 cm white paper frame. These were presented successively, without time limits. Participants were asked to point to the first perceived form and outline its contours and size in centimeters were recorded. Results In the first study, the results showed significant difference between CG and EG (F 1, 58 = 550, 62, p<0,001). Volunteers in EG selected average sizes (10-15° visual angle range) about three times higher than those selected by CG (4-5°visual angle range). In the second study, we placed each photograph in a transparent clear plastic folder, so that the responses were recorded directly in the cover using a marker, and then measured. Again, the instruction given to participants was to indicate which form was perceived first. After the volunteer responded, the form was circled and measured. The results also indicated statistically significant differences (F(23,966)=12,228,p<0,000) between EG and CG. The experimental group (EG) chose forms about 1.5 times larger than the control group (CG). Conclusion We suppose those differences can contribute as a differential indicator in the diagnostic of schizophrenia, mainly to detect the presence of positive symptoms. Thus, we suggest that those paintings by Dali could eventually be employed as a tool to assess the state of visual form perception in schizophrenic patients.