Eye movement impairments in children with malnutrition.

Malnutrition is characterised by deficient nutrient ingestion and absorption and is still one of the most important causes of morbidity and mortality in children worldwide. Our main rationale was that protein-energy malnutrition (PEM) may affect eye movement in children with malnutrition. Twenty children without PEM (mean age = 10.8; SD = 1.0 years) and 18 children with PEM (mean age = 10.9; SD = 1.2 years) were included in the present study. We applied three types of tests: one that consisted of a maze and two versions of the Spot the Seven Errors test using boats and elephants. Our results indicated that children with PEM exhibited performance deficits in the maze test (p < .001) and Spot the Seven Errors test for both boats (p < .001) and elephants (p < .001). These data suggest that nutritional impairments during the first year of life (i.e., a critical period) can directly impact eye movement. Eye tracking is a reliable technique to investigate higher-order processes, but our results should be interpreted with caution. Our findings highlight the relevance of cognitive development in malnourished children, which can negatively affect their development. Screening, assessment and rehabilitation strategies are essential in this at-risk population.

Relation between smoking and visual processing in bipolar disorder.

Background: Although some studies have shown impairments in patients with bipolar disorder (BPD) and in smokers, it is unclear how these two factors work together. Our premise was that chronic smoking affects color discrimination and this is more pronounced in BPD. Objective: Our main purpose was to investigate the influence of smoking and BPD on color discrimination. Methods: Twenty-three smokers and 23 BPD smokers patients, aged 25-45 years old, participated in this study. Color vision testing was performed using the Trivector subtest of the Cambridge Colour Test. Participants' task was to indicate the pseudoisochromatic stimulus in four directions (up, down, right, and left). Results: It was shown that the smokers had better color vision than BPD smokers for the Protan (p < .001), Deutan (p < .001), and Tritan (p < .001) (red, green, and blue, respectively) axes. Thus, the BPD smokers' group had greater difficulty distinguishing the chromaticity variations (i.e., presented diffuse color vision impairments and not specific to any axis). Conclusions: The present study highlights a possible relationship between smoking and BPD in color discrimination. This highlights the importance of understanding the diffuse effects of this relationship.

Combined influence of medication and symptom severity on visual processing in bipolar disorder.

Previous studies have reported visual impairments in patients with bipolar disorder (BPD), but unclear were whether clinical variables would be associated with those disturbances. Here, we investigate the relationship between visual functioning, in terms of color discrimination, and the impact of BPD duration, mood state, and the patients' medication. Forty-five participants (25-45 years old) were recruited for this study. Color discrimination was performed using the Cambridge Colour Test. Serial multiple mediations were run to investigate the assumption of association between color discrimination and the clinical variables. Our findings showed that, compared with healthy controls, BPD patients' performance was worse for the Protan, Deutan, and Tritan vectors, revealing deterioration of color discrimination. In addition, the mediation analyses revealed a strong direct (p < .001) and moderate-to-high indirect effects (p < .01) of medication and symptom severity on color discrimination. Overall, both longer the duration of the disease and greater the symptom severity of BPD patients resulted in worse performance. It highlights the importance of examining the wider clinical context of an affective disorder to understand how it affects visual processing in this population.

Heavy and light smokers have slight differences in chromatic discrimination.

Objectives: The effects of smoking on color vision have been scarcely studied. To bridge such gap, this study examined if there were differences in chromatic discrimination between heavy and light smokers. Methods: The psychophysical Trivector test was used to evaluate chromatic discrimination in healthy controls (n = 36), heavy smokers (n = 29), and light smokers (n = 32). The subject's task was to identify the orientation of the Landolt C ring gap - presented and randomized in one of the four positions (e.g., up, down, right, and left). Results: The thresholds for Protan (red), Deutan (green) and Tritan (blue) were higher in heavy smokers compared to nonsmokers but not to light smokers. Conclusions: The results confirm that heavy smoking and chronic exposure to its harmful compounds affect color discrimination when compared to light smoking; and this is more pronounced in heavy smokers than light smokers. This is particularly important to understand the differences among smokers on visual and multisensory processing.

Serum levels of olanzapine are associated with acute cognitive effects in bipolar disorder.

Bipolar (BPD) patients have deficits in cognition, but there are still controversies about the effects of some medications on their cognitive performance. Here, we investigated the relationship between cognition in terms of executive functions, memory, and attention in both first-episode medication-naive BPD patients and BPD patients taking olanzapine. Forty-one healthy controls, 40 unmedicated drug-naive BPD patients, and 34 BPD patients who took only olanzapine were recruited for the study. Cognitive performance was assessed using the Flanker test, Stroop test, and Corsi-block test. Bayesian multivariate regression analysis was run considering maximum robustness to avoid bias and to predict the outcomes. Our results revealed that unmedicated medication-naive BPD patients performed worse than healthy controls and the olanzapine group in some tasks. Additionally, BPD patients who took olanzapine had better cognitive performance than healthy controls and unmedicated BPD patients. The acute cognitive effects were predicted by olanzapine dosage and serum levels (i.e., large effects). The potential pro-cognitive effects of olanzapine in BPD patients should be carefully interpreted by considering various other clinical variables. We expect that our findings will contribute to further research in this area, with the goal of helping other researchers, patients, and the population.

Nicotine gum enhances visual processing in healthy nonsmokers.

OBJECTIVE: The main purpose of this study was to investigate the isolated effects of nicotine on visual processing, namely contrast processing. METHODS: Thirteen participants, aged 18-40 years, were enrolled in this double blind, randomized and pilot controlled trial involving nicotine gum administration (placebo, 2-mg and 4-mg doses). The participants' instruction was to detect the location of vertical gratings (0.2; 1.0; 3.3; 5.7; 8.8; 13.2 and 15.9 cycles per degree) when it was presented either left or right on the monitor screen. A repeated multivariate analysis of variance was conducted to analyse the results for the visual processing tasks. Bayesian analyses were also carried out considering maximum robustness to avoid bias. RESULTS: The findings that nicotine gum administration resulted in better contrast discrimination when compared to placebo gum (p < .001). More specifically, the 4-mg resulted in better visual sensitivity when compared to the 2-mg (p < .01) and the placebo (p < .001) gum. Demographic data were not related to the outcomes. CONCLUSIONS: These data bring the need for support the findings. If proved, it is possible that nicotine, in small doses, can have a potential therapeutic use for those populations with low vision. TRIAL REGISTRATION NUMBER: RBR-46tjy3.

Short-term effects of nicotine gum on facial detection in healthy nonsmokers: a pilot randomized controlled trial.

Objective: The main purpose of this study was to investigate short-term effects of nicotine gum on facial detection. Methods: Fourteen participants (mean age = 26.8 years, SD = 2.5 years; eight males) were enrolled in this pilot randomized controlled trial of nicotine gum administration (placebo, 2-mg and 4-mg doses). The participants were instructed to detect the location of a face when it was presented in a face/nonface pair on the screen. A repeated multivariate analysis of variance was conducted to analyze the results for reaction time and discrimination index. Demographics were used to explore significant association on facial detection. Bayesian analyses were also carried out considering maximum robustness to avoid bias. Results: The results indicated that the 2-mg dose resulted in faster reaction time and better discrimination than the 4-mg dose (p < 0.001). The 4-mg dose resulted in slower reaction time and lower discrimination index compared to both placebo (p < 0.01) and 2-mg doses (p < 0.001). Demographic data were not related to the outcomes. Conclusions: The results indicate that nicotine improved facial detection, but only at low doses (i.e., 2-mg), following a U-shaped curve. We trust future studies will continue to advance this research field, and if further work supports these preliminary findings, nicotine can act as therapeutic target in populations such as those with low vision.

Impairments of facial detection in tobacco use disorder: baseline data and impact of smoking duration.

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.

Combined influence of illness duration and medication type on visual sensitivity in schizophrenia.

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.

Opposite effects of smoking and nicotine intake on cognition.

Our main purpose was to investigate how smoking and nicotine interacted with specific aspects of cognitive functioning. The research was conducted in two parts: (i) an investigation of cognition in heavy smokers and healthy nonsmokers, and (ii) an investigation of cognition in healthy nonsmokers enrolled in a clinical trial involving administration of nicotine gum. Results indicated that the relationship between smoking and nicotine was characterized by an inverted U-shaped effect. On the one hand, cognitive test performance of the heavy smokers group was reduced on all of the cognitive tasks used here. On the other hand, healthy nonsmokers who used 2-mg of nicotine gum performed better, whilst the 4-mg group performed worse than the 2-mg and the placebo group. Demographic data were not related to the cognitive tasks. These data suggest that small doses of nicotine can have an activating function that leads to improved cognition, while heavy smoking on a chronic (and possibly acute) basis leads to cognitive impairment.

Visual impairments in tobacco use disorder.

Prior studies found small effects of chronic smoking on spatial and color vision, but they were inconclusive. This study tries to: (1) replicate and extend these previous findings, and (2) rule in that this relationship is pronounced by tobacco addiction. Data were recorded in 71 healthy controls (M = 33.5 years; SD = 5.4 years) and 63 individuals with tobacco addiction (M = 34.7 years; SD = 4.8 years). Visual processing was assessed in the forms of contrast sensitivity for linear sine-wave gratings (spatial frequencies ranging between 0.2 and 16 cycles per degree) and color discrimination (using the Ellipse and Trivector subtests). The groups were matched for age, gender and level of education. The group with heavy smokers had reduced sensitivity for all spatial frequencies (p < .001), and impairments in color discrimination for both Trivector (all p-values < .001 for Protan, Deutan and Tritan) and Ellipse (all p-values < .001). This study consistently replicates and extended previous findings, and showed that visual processing can be strongly associated with tobacco addiction. These results indicate that excessive use of cigarettes, or chronic exposure to their compounds, affects visual discrimination, supporting the existence of overall deficits in visual processing in tobacco addiction.

Visual impairments in type 1 bipolar disorder.

Objectives: The present study evaluated early visual processing, in terms of the contrast sensitivity function (CSF), in bipolar disorder (BPD) patients.Methods: Data were recorded in 17 healthy participants and 17 outpatients with type 1 BPD, from 20 to 45 years of age. The CSF was measured at spatial frequencies of 0.2, 0.6, 3.1, 8.0, 16.0 and 20.0 cycles per degree (cpd) using Gabor patches and a two-alternative, forced-choice, logarithmic staircase method. The groups were matched for gender, age and level of education.Results: The CSF differed between groups. Patients with BPD had lower discrimination at spatial frequencies of 0.2 cpd (P < 0.001), 0.6 cpd (P < 0.001), 16.0 cpd (P < 0.001) and 20.0 cpd (P < 0.001) compared with healthy subjects. No differences were observed at 3.1 cpd (P > 0.05) and 8.0 cpd (P > 0.05). This visual impairment was related both to longer duration of illness and to greater severity of manic symptoms.Conclusions: The differences in visual processing were pronounced in patients with BPD, which justifies further investigations of the pathophysiological mechanisms that are involved in sensorial alterations.

O Papel bidirecional da nicotina na tarefa Go/No-go: um ensaio clínico piloto / The bidirectional role of nicotine in a Go/No-go task: a pilot clinical trial / El papel bidireccional de la nicotina en la tarea Go/no-go: un ensayo clínico piloto

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 (AU).

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 (AU).

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 (AU).

Combined influence of illness duration and medication type on visual sensitivity in schizophrenia

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.