Estudos envolvendo portadores de esquizofrenia têm mostrado alterações severas da percepção e cognição. A maioria dos diagnósticos, entretanto, é baseada na avaliação de processos cognitivos. Nossos estudos investigaram a percepção alterada de forma e tamanho em pacientes com esquizofrenia e com depressão maior utilizando 24 pinturas de Salvador Dalí. Conduzimos dois estudos comparando grupos experimental e controle e observamos, em ambos os casos, que os portadores de esquizofrenia perceberam figuras 1,5 e 3,0 vezes maior do que os respectivos grupos controle. Em outro estudo com pacientes com depressão maior não foram observadas alterações na percepção de tamanho comparado ao grupo controle. Concluímos que este efeito de percepção de forma e tamanho alterados pode servir como marcador no diagnóstico precoce da presença de sintomas positivos na esquizofrenia. Sugerimos que estas pinturas de Salvador Dalí sejam utilizadas como ferramenta para avaliar alterações na percepção de formas e tamanhos em pacientes portadores de esquizofrenia e, assim, prevenir o agravamento dos sintomas cognitivos.

The objective of this research was to measure possible changes in visual size perception of patients with depression and schizophrenia. Three groups were compared: Control Group (CG), Schizophrenia Group (SchG) and Depression Group (DepG). The diameter of the first figure seen by the participants in each painting was recorded in degrees of visual angle. The SchG perceived images 1.47 larger than CG and the DepG 1.28 larger than CG, whereas SchG selected images 1.15 larger than DepG, F (2, 57) = 17.677, p < .0001. These findings suggest there are changes in visual size perception related to depression and schizophrenia.

The present study evaluated the effects of major depression on visual contrast sensitivity (CS) at low mesopic luminance (.7 cd/m 2 mean luminance), a condition that has been little explored in the literature. We measured spatial visual CS in 20 male volunteers aged 20 -30 years, including 10 healthy individuals and 10 medicated individuals with major depression, to linear sine-wave gratings of .25, 1.0, and 4.0 cycles per degree (cpd) of visual angle using the psychophysical staircase method with forced choice. The average spatial visual CS in the depressed group was approximately 1.7 lower than the average spatial visual CS in the control group. However, the post hoc test showed significant differences only at the spatial frequencies of .25 and 1.0 cpd (p < .05), which are likely processed by the magnocellular visual pathway. These results suggest that spatial visual CS to sine-wave gratings should be used to evaluate the responsiveness of the visual system in patients with major depression under conditions of low luminance.

In this study, we compared visual pictorial size perception between healthy volunteers (CG) and an experimental group (EG) of people diagnosed with schizophrenia. We have been using paintings by Salvador Dalí and Rorschach plates to estimate visual pictorial size perception. In this transversal, ex post facto, and quasi-experimental study, we observed differences between EG and CG. Schizophrenic in-patients perceived sizes about 1.3-fold greater than healthy volunteers (p=0.006), implying that pictorial size perception is altered in some way in schizophrenia. Considering the present and previous results, this measurement of diameter size of first pictorial perception may be a useful estimate of some aspects of perceptual alterations that may be associated with psychotic symptoms in prodromal and acute schizophrenic episodes and other related mental states. Eventually, this may help in preventing people from evolving to acute episodes.

Major depression is a disorder with a high prevalence in women and is associated with biological, affective, and cognitive changes. In the present study we evaluated the pattern of recognition and emotional attribution in women with major depressive disorder and healthy volunteers. Facial expressions of four basic emotions (happiness, fear, sadness, and anger) that were presented at four intensities (25, 50, 75, and 100%) and neutral faces were used as stimuli. Compared with healthy volunteers, women who were diagnosed with depression showed a negative bias in emotional processing. The clinical group showed greater recognition of sadness with the lowest emotional intensity (25%) compared with the control group (p = .013). With regard to emotional attribution, the analysis revealed a statistically significant difference between groups (χ² = 10.30) in which women with major depression tended to assign the emotion of sadness to neutral faces more often (p < 0.01). The results indicate that depressive symptoms are associated with cognitive and emotional bias, which may affect interpersonal functioning in women with major depressive disorder.