Resumo Estudos mostram que o tabagismo é responsável por afetar algumas funções cognitivas. No entanto, a nicotina é apenas um dos componentes existentes no cigarro e existem evidências de que pode servir como agente neuroprotetivo e causar melhoras em algumas funções cognitivas. O objetivo desta pesquisa foi investigar como a nicotina interage com algumas funções cognitivas. Um ensaio clínico piloto com administração de gomas de nicotina contendo 2-mg ou 4-mg, ou gomas placebo contendo a mesma textura, sabor e aparência, foi realizado. Quarenta e dois participantes participaram da pesquisa e os resultados indicaram que a relação entre nicotina e o desempenho na tarefa Go/No-Go podem ser bidirecionais. Os resultados indicaram que participantes do grupo que utilizaram 4-mg de nicotina apresentaram menor desempenho, enquanto os participantes que fizeram uso de 2-mg de nicotina tiveram melhor desempenho do que os demais. Esta pesquisa tem aplicações biopsicossociais e podem ajudar na compreensão da relação entre tabagismo e nicotina, além de contribuir para estratégias que possam ajudar no abandono do cigarro ou na melhora de condições que afetem a cognição.

Abstract Past findings in the literature indicated that smoking could affect given cognitive functions. However, nicotine is only one of the components in cigarettes and there is evidence that it may act as a neuroprotective agent and improve some cognitive functions. The purpose of this research was to investigate how nicotine interacts with certain cognitive functions. We conducted a pilot clinical trial using nicotine gum containing 2-mg or 4-mg, or placebo gum with the same texture, flavor, and appearance. Forty-two healthy nonsmokers were enrolled in this research. Our findings indicated that the relationship between nicotine and performance on the Go/No-Go task might be opposite. The results showed that participants in the 4-mg group performed worse, while participants who used 2-mg of nicotine performed better than the others. This research supports biopsychosocial applications and can help interpret the relationship between smoking and nicotine, and contribute to strategies that may support smoking cessation, or improve conditions that affect cognition.

Resumen Estudios demuestran que el tabaquismo es responsable de afectar a algunas funciones cognitivas. Sin embargo, la nicotina es solo uno de los componentes de los cigarrillos, y existen evidencias de que la nicotina puede actuar como un agente neuroprotector y mejorar algunas funciones cognitivas. El objetivo de este estudio fue investigar cómo la nicotina interactúa con algunas funciones cognitivas. Se realizó un ensayo clínico piloto con la administración de chicles de nicotina de 2 mg o 4 mg, o chicles de placebo con la misma textura, sabor y apariencia. Cuarenta y dos participantes participaron en la investigación y los resultados indicaron que la relación entre la nicotina y el rendimiento en la tarea Go/No-go puede ser bidireccional. Los resultados indicaron que los participantes del grupo de 4 mg obtuvieron un menor rendimiento en las variables del Go/No-Go, mientras que los participantes que utilizaron 2 mg de nicotina obtuvieron un mejor rendimiento que los demás. Esta investigación respalda las aplicaciones biopsicosociales y puede ayudar a interpretar la relación entre el tabaquismo y la nicotina, además de contribuir a las estrategias que pueden ayudar a dejar de fumar o mejorar las condiciones que afectan la cognición.

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.