Objective: The process of detecting faces can be considered one of the initial steps in face recognition, which is essential for human interaction. We sought to investigate whether a face perception task reliably detects subtle perceptual disturbances between patients with bipolar disorder (BD) and healthy controls. Methods: In this multisite study, we examined differences between BD patients and matched healthy controls. Participants were instructed to detect the orientation (either left or right) of a face when it was presented as a face/non-face pair on a computer screen using Bayesian entropy estimation. Data analyses compared performance between the groups. Results: Overall, BD patients exhibited more perceptual disturbances compared with controls. BD patients who took olanzapine had better performance and faster reaction times (RTs) than patients who took lithium or were medication-naive. BD patients who took lithium had better performance and faster RTs than medication-naive patients. The medication-naive BD group exhibited greater disturbances than all other groups. Conclusion: These findings highlight the reliability of the face perception task used herein and may be important for public health initiatives and follow-up studies that seek to understand the diverse effects of other variables that can affect sensory processing in this population.

Objective: Chronic tobacco consumption, classified as tobacco use disorder (TUD), has been associated with a variety of health problems. Investigations of face processing in TUD are hampered by lack of evidence. Here, we evaluated facial detection in TUD and assessed test-retest reliability for a facial detection task. Methods: Participants were instructed to detect the orientation (either left or right) of a face when it was presented with a face/non-face pair on the monitor screen, using Bayesian entropy estimation. Bland-Altman analysis and intraclass correlation coefficients were used to test the reliability of the task. The general linear model and Bayesian statistics were then used to evaluate differences between TUD (n=48) and healthy controls (n=34). Results: The reliability of the task was high for the 96 stimuli presentations. Slower reaction times (p < 0.001) and lower discrimination index (p < 0.001) were observed in the TUD group than for healthy controls. Mediation analysis indicated direct effects of smoking duration on reaction time (p < 0.001) and discrimination index (p < 0.001). Conclusions: Overall, we observed high reliability of this task and reduction of facial detection in tobacco use disorder. We conclude our findings are significant for public health initiatives and call for follow-up studies.

Objective: Patients with schizophrenia have visual processing impairments. The main findings from the literature indicate that these deficits may be related to differences in paradigms, medications, and illness duration. This study is part of a large-scale study investigating visual sensitivity in schizophrenia. Here we aimed to investigate the combined effects of illness duration and antipsychotic use on contrast sensitivity function. Methods: Data were collected from 50 healthy controls and 50 outpatients with schizophrenia (classified according to illness duration and medication type) aged 20-45 years old. The contrast sensitivity function was measured for spatial frequencies ranging from 0.2 to 20 cycles per degree using linear sine-wave gratings. Results: Patients with an illness duration > 5 years had more pronounced deficits. Differences in the combined effects of illness duration and antipsychotic use were marked in patients on typical antipsychotics who had been ill > 10 years. No significant differences were found between typical and atypical antipsychotics in patients with an illness duration < 5 years. Conclusion: Visual impairment was related to both long illness duration and medication type. These results should be tested in further studies to investigate pharmacological mechanisms.

Early malnutrition refers to inadequate nutrition during the critical period of nervous system development followed by nutritional recovery, resulting in a short stature according to age but normal weight according to short stature. We measured the effects of early malnutrition on contrast sensitivity (CS) to concentric circular gratings in 18 children of both sexes, aged 8 to 11 years (mean = 9.2 years, standard deviation = .99 years). Nine of the children were eutrophic (E group), and nine experienced early malnutrition (EM group) based on state healthcare records and Waterlow's anthropometric parameters. Contrast sensitivity to four spatial frequencies (.25, 1.0, 2.0, and 8.0 cycles per degree [cpd]) was measured using a temporal two-alternative forced-choice psychophysical method with mean luminance of 40.1 cd/m². Statistical analyses showed significant differences between groups and a group × frequency interaction. EM group was significantly less sensitive than the E group to the 8.0 cpd frequency and needed 1.49-times more contrast to detect the gratings. These results suggest that early malnutrition impairs CS to high-spatial-frequency concentric circular gratings in children. Therefore, early malnutrition, which is known to affect primary visual cortical areas, may also affect higher visual cortical areas such as V4 and the inferotemporal cortex.

We measured the effects of epilepsy on visual contrast sensitivity to linear and vertical sine-wave gratings. Sixteen female adults, aged 21 to 50 years, comprised the sample in this study, including eight adults with generalized tonic-clonic seizure-type epilepsy and eight age-matched controls without epilepsy. Contrast threshold was measured using a temporal two-alternative forced-choice binocular psychophysical method at a distance of 150 cm from the stimuli, with a mean luminance of 40.1 cd/m². A one-way analysis of variance (ANOVA) applied to the linear contrast threshold showed significant differences between groups (F[3,188] = 14.829; p < .05). Adults with epilepsy had higher contrast thresholds (1.45, 1.04, and 1.18 times for frequencies of 0.25, 2.0, and 8.0 cycles per degree of visual angle, respectively). The Tukey Honestly Significant Difference post hoc test showed significant differences (p < .05) for all of the tested spatial frequencies. The largest difference between groups was in the lowest spatial frequency. Therefore, epilepsy may cause more damage to the neural pathways that process low spatial frequencies. However, epilepsy probably alters both the magnocellular visual pathway, which processes low spatial frequencies, and the parvocellular visual pathway, which processes high spatial frequencies. The experimental group had lower visual contrast sensitivity to all tested spatial frequencies.

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.

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. Our studies evaluate altered visual form and size perception in schizophrenic and major depression patients using 24 paintings by Salvador Dalí. We conducted two studies comparing experimental and control groups and found in both cases that schizophrenic patients first saw forms 1.5-3.0 times larger than controls. In another study with major depression patients, we show the absence of alterations in size perception during aggravated depressive symptoms. These effects on size perception can contribute as markers in the precocious diagnostic of the onset of positive symptoms in schizophrenia. We suggest that these paintings by Dalí can be employed as a tool to assess the state of visual form and size perception in schizophrenic patients, and therefore prevent cognitive deterioration by introducing early treatment.

Estudios con pacientes con esquizofrenia han mostrado cambios severos en la percepción y la cognición. La mayoría de los diagnósticos, sin embargo, se basa en la evaluación de los procesos cognitivos. Hemos utilizado 24 pinturas de Salvador Dalí para investigar los cambios en la percepción de la forma y el tamaño en los pacientes esquizofrénicos y con depresión mayor. Aquí se presentan dos estudios que compararon grupos experimental y control. En ambos, observamos que los pacientes con esquizofrenia vieron las imágenes presentadas como 1.5 y 3.0 veces mayores en comparación con los grupos control. En otro estudio, los pacientes con depresión mayor no mostraron cambios en el tamaño percibido en comparación con el grupo control. Se concluye que los cambios en la percepción de la forma y el tamaño pueden servir como un marcador para el diagnóstico precoz de los síntomas positivos en la esquizofrenia. Sugerimos que estas pinturas de Salvador Dalí sean utilizadas como un instrumento para evaluar los cambios en la percepción de formas y tamaños en los pacientes esquizofrénicos y así prevenir el agravamiento de los síntomas cognitivos.

Les études de patients schizophrènes ont montré d'importantes modifications dans la perception et la cognition. La plupart des diagnostics, toutefois, est basé sur l'évaluation des processus cognitifs. Nous avons utilisé 24 tableaux de Salvador Dalí pour étudier les modifications en la perception de forme et dimension des patients schizophrènes et de patients souffrant de dépression majeure. Ici sont présentés deux études comparant des groupes expérimental et de contrôle. Dans les deux, patients schizophrènes ont vu les images présentées comme étant de 1,5 et 3,0 fois plus grand par rapport au groupe contrôle. Dans une autre étude, les patients souffrant de dépression majeure n'ont montré aucune changement en dimension perçue en comparaison au groupe de contrôle. Nous concluons que les changements dans la perception de forme et dimension peuvent servir de marqueur pour le diagnostic précoce des symptômes positifs de la schizophrénie. Nous suggérons que ces peintures de Salvador Dalí sont utilisés comme un instrument pour évaluer les changements dans la perception de formes et de dimensions des patients schizophrènes et d'éviter ainsi l'aggravation des symptômes cognitifs.