The goal of the present study was to investigate the monocular perception of the depth or relief of the concave mask by 29 healthy subjects: seven individuals with schizophrenia under use of antipsychotic for a period less than or equal to four week and 29 under use of antipsychotic for a period bigger than four week. The three groups classified the reverse of a mask in two situations polychromatic illumination from above and below. The results showed most of the subjects with schizophrenia made the monocular depth inversion of a concave mask and perceived it as convex. The individuals with schizophrenia on antipsychotic medication for longer than four weeks period estimated the convexity of illuminated concave mask over into shorter length compared to healthy individuals and therefore susceptible to the illusion of concave mask.
hollow-mask; schizophrenia; visual inversion
