Although some studies have reported perceptual changes in psychosis, no definitive conclusions have been drawn about visual disturbances that are related to bipolar disorder (BPD). The purpose of the present study was to evaluate colour vision in BPD patients. Data were recorded from 24 participants: healthy control group (n = 12) and type 1 BPD group (n = 12). The participants were 20–45 years old and they were free from neurological disorders and identifiable ocular disease and had normal or corrected-to-normal visual acuity. Colour discrimination was evaluated using the Lanthony D-15d, Trivector and Ellipse tests, using a psychophysical forced-choice method. The relationship of visual measures to mood state and cognitive function was also investigated. The results showed that BPD patients had higher colour discrimination thresholds in the D15d (p < 0.001), Trivector (p < 0.001) and Ellipse (p < 0.01) tests compared with healthy controls. Linear regression analysis showed that mood state was related to colour discrimination. BPD individuals were not impaired in cognitive tasks. The present study provided new evidence of potential links between type 1 BPD and visual processing impairments. This research suggests a new direction for studies and the need for research in this field of study.

Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.

This article aims to demonstrate the utilities of Matlab (MATrix LABoratory) and eye-tracker for research in psychophysics and basic processes. We fi rst introduce its origin, functioning, and advantages over other programs, and then we review different applications of Matlab in psychophysical tests involving eye-trackers. As an example, we present the development of a psychophysical test involving eye-tracker and Matlab, showing its ability to communicate and interact with other devices and programming languages. Finally, we emphasize the advantages and diffi culties of working with Matlab.Keywords: Psychophysics, Matlab, Eye-tracker, technological innovation. Matlab e Rastreamento Ocular: Aplicações em Psicofísica e Processos Psicológicos Básicos ResumoEsse artigo teve como objetivo demonstrar a funcionalidade e capacidade do Matlab (MATrix LABoratory) e rastreamento de movimentos oculares (eye-tracker) para pesquisas em psicofísica e processos básicos. Para isso é apresentado primeiramente os fundamentos da criação e funcionamento do Matlab e suas vantagens sobre outros softwares. Em seguida são apresentadas diferentes aplicações do Matlab em testes psicofísicos com rastreadores de movimentos oculares (eyetracker). Também é apresentada a criação de um teste psicofísico em Matlab para um eyetracker e sua capacidade de se

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 coronavirus disease (COVID-19) pandemic has overwhelmed health care systems in many countries and bed availability has become a concern. In this context, the present study aimed to analyze the hospitalization and intensive care unit (ICU) times in patients diagnosed with COVID-19. The study covered 55,563 ICU admissions and 238,075 hospitalizations in Brazilian Health System units from February 22, 2020, to June 7, 2021. All the patients had a positive COVID-19 diagnosis. The symptoms analyzed included: fever, dyspnea, low oxygen saturation (SpO2 < 95%), cough, respiratory distress, fatigue, sore throat, diarrhea, vomiting, loss of taste, loss of smell, and abdominal pain. We performed Cox regression in two models (ICU and hospitalization times). Hazard ratios (HRs) and survival curves were calculated by age group. The average stay was 14.4 days for hospitalized patients and 12.4 days for ICU patients. For hospitalized cases, the highest hazard mean values, with a positive correlation, were for symptoms of dyspnea (HR = 1.249; 95% confidence interval [CI], 1.225–1.273) and low oxygen saturation (HR = 1.157; 95% CI 1.137–1.178). In the ICU, the highest hazard mean values were for respiratory discomfort (HR = 1.194; 95% CI 1.161–1.227) and abdominal pain (HR = 1.100; 95% CI 1.047–1.156). Survival decreased by an average of 2.27% per day for hospitalization and 3.27% per day for ICU stay. Survival by age group curves indicated that younger patients were more resistant to prolonged hospital stay than older patients. Hospitalization was also lower in younger patients. The mortality rate was higher in males than females. Symptoms related to the respiratory tract were associated with longer hospital stay. This is the first study carried out with a sample of 238,000 COVID-19 positive participants, covering the main symptoms and evaluating the hospitalization and ICU times.