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2.
J Psychiatr Res ; 163: 421-429, 2023 07.
Article in English | MEDLINE | ID: mdl-37276646

ABSTRACT

Bipolar disorder (BPD) is a chronic condition characterized by recurrent episodes of mania and depression. To date, the association of biological and psychopathological processes in BPD has not been extensively studied on a cognitive and cortical basis at the same time. We investigated whether brain atrophy (in prefrontal, temporal and occipital cortices) was associated with cognitive, biological and clinical processes in patients with BPD and healthy controls (HCs). A total of 104 participants (56 with BPD) completed tasks that measured attention, memory, information processing speed, inhibitory control, visuospatial working memory and cognitive flexibility. In addition, structural brain scans were obtained using high-resolution MRI. Outcomes of the measurements were examined using robust multiple mediation analyses. BPD patients showed greater cortical atrophy across all regions of interest when compared to HCs, linked to cognitive decline. BPD patients had slower reaction times and markedly increased errors of commission on the tasks. The outcomes were significantly influenced by medication use, symptomatology and illness duration. The findings showcase the complexity of brain structures and networks as well as the physiological mechanisms underlying diverse BPD symptomatology and endophenotypes. These differences were pronounced in patients with BPD, motivating further investigations of pathophysiological mechanisms involved in brain atrophy and cognitive decline.


Subject(s)
Bipolar Disorder , Cognitive Dysfunction , Neurodegenerative Diseases , Humans , Bipolar Disorder/complications , Bipolar Disorder/diagnostic imaging , Bipolar Disorder/drug therapy , Brain/diagnostic imaging , Brain/pathology , Memory, Short-Term/physiology , Neurodegenerative Diseases/complications , Magnetic Resonance Imaging , Cognitive Dysfunction/etiology , Cognitive Dysfunction/complications , Atrophy/complications , Atrophy/pathology
3.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 44(6): 602-610, Nov.-Dec. 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1420522

ABSTRACT

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.

4.
Sci Rep ; 12(1): 9072, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35641546

ABSTRACT

Our past anecdotal evidence prompted that a longer response window (RW) in the Trivector test (Cambridge Colour Test) improved mature observers' estimates of chromatic discrimination. Here, we systematically explored whether RW variation affects chromatic discrimination thresholds measured by the length of Protan, Deutan and Tritan vectors. We employed the Trivector test with three RWs: 3 s, 5 s, and 8 s. Data of 30 healthy normal trichromats were stratified as age groups: 'young' (20-29 years), 'middle-aged' (31-48 years), and 'mature' (57-64 years). We found that for the 'young' and 'middle-aged', the thresholds were comparable at all tested RWs. However, the RW effect was apparent for the 'mature' observers: their Protan and Tritan thresholds decreased at 8-s RW compared to 3-s RW; moreover, their Tritan threshold decreased at 5-s RW compared to 3-s RW. Elevated discrimination thresholds at shorter RWs imply that for accurate performance, older observers require longer stimulus exposure and are indicative of ageing effects manifested by an increase in critical processing duration. Acknowledging low numbers in our 'middle-aged' and 'mature' samples, we consider our study as pilot. Nonetheless, our findings encourage us to advocate a RW extension in the Trivector protocol for testing mature observers, to ensure veridical measures of their chromatic discrimination by disentangling these from other ageing effects-slowing down of both motor responses and visual processing.


Subject(s)
Color Perception Tests , Color Perception , Cognition , Color Perception/physiology , Color Perception Tests/methods , Visual Perception
5.
Int J Psychol ; 57(5): 644-651, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35262928

ABSTRACT

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.


Subject(s)
Elephants , Protein-Energy Malnutrition , Animals , Eye Movements , Humans , Protein-Energy Malnutrition/epidemiology
6.
J Addict Dis ; 40(4): 568-576, 2022.
Article in English | MEDLINE | ID: mdl-35264083

ABSTRACT

Chronic tobacco consumption, identified as Tobacco Use Disorder (TUD), is a public health problem. We present a case report of a 37-year-old Brazilian male diagnosed with TUD at age 26, with no comorbidities, that presented visual improvements (i.e., lower thresholds and better discrimination) after nicotine gum administration. Here, we assessed contrast sensitivity and chromatic discrimination using the Metropsis and the Cambridge Colour Test, respectively. Results showed lower thresholds for both visual tasks after the use of nicotine gum. Even considering this is a single case report, our intent is to open new avenues for research involving smoking, addiction and the use of nicotine gum as a replacement tool or adjuvant tool for improvement of visual and/or cognitive processing. It is well known that nicotine gum has protective effects for some diseases, and improves some cognitive functions. However, unclear were its effects on visual processing of people with TUD.


Subject(s)
Smoking Cessation , Tobacco Use Disorder , Adult , Humans , Male , Nicotine/therapeutic use , Smoking/psychology , Smoking Cessation/methods , Tobacco Use Cessation Devices , Tobacco Use Disorder/drug therapy
7.
J Psychiatr Res ; 149: 323-330, 2022 05.
Article in English | MEDLINE | ID: mdl-35339912

ABSTRACT

The use of noninvasive tools can help understand mental states and changes that are caused by medications, symptom severity, and other clinical variables. We investigated low-level visual processing using the contrast sensitivity function (CSF), a reliable, robust, and widely used approach. Our main purpose was (1) to evaluate visual impairments in schizophrenia (SCZ) and bipolar disorder (BPD) patients and (2) to investigate associations between clinical variables and visual function in both diseases. Fifty-six healthy controls (HCs; mean age = 31.04 years), 42 BPD patients (mean age = 32.84 years) who took only lithium, and 39 SCZ patients who took only olanzapine (mean age = 32.80 years) were recruited for this study. CSF differed between groups. Both groups of patients exhibited lower discrimination at low, mid-, and high spatial frequencies compared with HCs. No differences were observed between patients, with the exception of high spatial frequency. These impairments were also related to clinical variables, revealed by a strong effect in the mediation analyses. These findings may aid investigations of other clinical variables and the role of state- and trait-like effects on visual and cognitive processing in these patient populations. This study underscores the need for visual remediation interventions.


Subject(s)
Bipolar Disorder , Schizophrenia , Adult , Bipolar Disorder/complications , Cognition , Humans , Visual Perception
8.
Psychiatry Res ; 310: 114443, 2022 04.
Article in English | MEDLINE | ID: mdl-35286918

ABSTRACT

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.


Subject(s)
Bipolar Disorder , Bayes Theorem , Bipolar Disorder/complications , Bipolar Disorder/drug therapy , Bipolar Disorder/psychology , Cognition , Executive Function , Humans , Neuropsychological Tests , Olanzapine/therapeutic use
9.
J Psychiatr Res ; 147: 135-141, 2022 03.
Article in English | MEDLINE | ID: mdl-35032946

ABSTRACT

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.


Subject(s)
Bipolar Disorder , Adult , Bipolar Disorder/complications , Bipolar Disorder/drug therapy , Cognition , Color Perception , Humans , Middle Aged , Visual Perception
10.
Psico USF ; 27(1): 157-167, jan.-mar. 2022. tab, graf
Article in Portuguese | LILACS, Index Psychology - journals | ID: biblio-1376039

ABSTRACT

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).


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Executive Function , Nicotine Chewing Gum , Nicotine/administration & dosage , Placebos/administration & dosage , Tobacco Use Disorder/psychology , Chi-Square Distribution , Pilot Projects , Double-Blind Method , Analysis of Variance
11.
J Am Acad Audiol ; 33(4): 206-213, 2022 04.
Article in English | MEDLINE | ID: mdl-34847574

ABSTRACT

BACKGROUND: Psychiatric conditions are common in individuals with tinnitus. Therefore, the ways individuals cope with such conditions and personality can influence the characteristics of tinnitus. PURPOSE: The study aims to investigate the direct and indirect effects of resilience, personality traits, and psychiatric symptoms on the tinnitus perception. RESEARCH DESIGN: This is a descriptive, cross-sectional, and observational study involving quantitative results. STUDY SAMPLE: Thirty-seven individuals with chronic tinnitus (for more than 6 months) sought the tinnitus care service (mean age = 44.6 years; SD = 11.7 years). DATA COLLECTION AND ANALYSIS: The specific anamnesis of tinnitus, adult self-report questionnaire, resilience scale, big five inventory, Tinnitus Handicap Inventory (M = 45.0; SD = 24.1), and visual analog scale (M = 6.4; SD = 2.7) were used. Psychoacoustic measurements (loudness: M = 25.4; SD = 12.8) of tinnitus were performed to characterize the condition in terms of pitch and loudness. The study analyzed the relationship between tinnitus (annoyance, severity, and loudness), psychiatric symptoms, personality, and resilience using multiple mediations. RESULTS: Resilience did not influence tinnitus severity (BCa: -1.12 to 0.51), annoyance (BCa: -0.10 to 0.11), or loudness (BCa: -0.44 to 0.28) when mediated by anxiety and depression. Additionally, there was only a direct effect of resilience for annoyance (t = - 2.14, p = 0.03; BCa: -0.10 to 0.11). There was no direct influence of anxiety and depression on the tinnitus severity (b = 0.53, p > 0.05), annoyance (b = - 0.01, p > 0.05), or loudness (b = 0.11, p > 0.05). However, there was an association of personality traits (neuroticism) with the tinnitus severity (b = 1.16, 95% CI: 0.15-2.17; t = 2.53, p = 0.02) and annoyance (b = 0.12, 95% CI: 0.003-0.24; t = 2.09, p = 0.04). CONCLUSION: Resilience and psychiatric symptoms did not have a direct or indirect influence on the tinnitus annoyance, severity, or loudness. However with a direct association of resilience and annoyance, and neuroticism trait with the tinnitus annoyance and severity. Our results suggest that patients with chronic tinnitus and high neuroticism should receive personalized treatment.


Subject(s)
Tinnitus , Humans , Adult , Tinnitus/psychology , Cross-Sectional Studies , Anxiety , Personality , Perception
12.
J Addict Dis ; 40(2): 151-156, 2022.
Article in English | MEDLINE | ID: mdl-34338615

ABSTRACT

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.


Subject(s)
Color Perception Tests , Color Perception , Color Perception Tests/methods , Humans , Smokers , Smoking/epidemiology
13.
J Addict Dis ; 40(1): 71-77, 2022.
Article in English | MEDLINE | ID: mdl-34075846

ABSTRACT

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.


Subject(s)
Bipolar Disorder , Color Perception Tests , Adult , Color Perception , Humans , Middle Aged , Smoking/epidemiology , Visual Perception
14.
Braz J Psychiatry ; 44(6): 602-610, 2022 Oct 07.
Article in English | MEDLINE | ID: mdl-36682881

ABSTRACT

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.


Subject(s)
Bipolar Disorder , Humans , Bipolar Disorder/drug therapy , Bipolar Disorder/epidemiology , Emotions , Lithium/pharmacology , Bayes Theorem , Reproducibility of Results , Facial Expression , Magnetic Resonance Imaging
15.
Psychiatry Res ; 305: 114200, 2021 11.
Article in English | MEDLINE | ID: mdl-34653830

ABSTRACT

Previous studies have shown that patients diagnosed with schizophrenia (SCZ) have deficits in early visual processing, namely contrast processing. The brain-derived neurotropic factor (BDNF) is an important measure to investigate neuroplasticity in some visual functions like visual perception. In this study, we investigated the relationship between visual processing and BDNF levels in first-episode SCZ patients. Thirty-nine healthy controls and 43 first-episode SCZ patients were enrolled. Contrast sensitivity measurements were conducted using low, mid- and high spatial frequencies. First-episode SCZ patients had higher contrast sensitivity than healthy controls for all frequencies, except for the middle spatial frequency. Negative correlations were found between BDNF, contrast sensitivity and clinical variables, mostly for middle and high spatial frequencies among females. Our results provide support for (i) the association of SCZ with alterations of magno- and parvocellular pathway functioning and (ii) decreased BDNF levels in first-episode SCZ patients. This study highlights the importance of using biomarkers along with other measures to investigate visual processing in SCZ and other disorders.


Subject(s)
Brain-Derived Neurotrophic Factor , Schizophrenia , Visual Perception , Brain , Cognition , Female , Humans , Schizophrenia/diagnosis
16.
Dev Neuropsychol ; 46(7): 463-485, 2021 10.
Article in English | MEDLINE | ID: mdl-34595981

ABSTRACT

The use of serious games and entertainment games was compared as adjuvant tools for intervention in Autism Spectrum Disorder (ASD). A comprehensive search was performed in the MEDLINE, PsycINFO, Scopus, and Web of Science databases. From 295 studies, 53 studies were selected and included in this review. Overall, studies showed improvement after intervention, regardless of the type of video games, mostly for social skills and behavior. However, these changes should be regarded with caution, as they are limited to the tests applied. Furthermore, neither the entertainment nor the serious approach had a therapeutic impact on emotional resilience, representing the current gap in the field. Thus, even considering the limitations, our study is important because it shows that both categories have strengths.


Subject(s)
Autism Spectrum Disorder , Video Games , Autism Spectrum Disorder/therapy , Emotions , Humans
17.
Brain Imaging Behav ; 15(5): 2593-2605, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33675460

ABSTRACT

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.


Subject(s)
Nicotine , Smoking Cessation , Bayes Theorem , Double-Blind Method , Humans , Magnetic Resonance Imaging , Non-Smokers , Visual Perception
18.
J Addict Dis ; 39(1): 15-25, 2021.
Article in English | MEDLINE | ID: mdl-32856547

ABSTRACT

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.


Subject(s)
Facial Recognition , Gingiva , Healthy Volunteers/statistics & numerical data , Nicotine/administration & dosage , Non-Smokers , Reaction Time , Adult , Cotinine/blood , Female , Humans , Male , Pilot Projects
19.
Braz J Psychiatry ; 43(4): 376-384, 2021.
Article in English | MEDLINE | ID: mdl-32997076

ABSTRACT

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.


Subject(s)
Tobacco Use Disorder , Bayes Theorem , Humans , Reproducibility of Results , Smoking , Tobacco Use , Tobacco Use Disorder/diagnosis
20.
Front Hum Neurosci ; 14: 314, 2020.
Article in English | MEDLINE | ID: mdl-33100983

ABSTRACT

Studies reported that tobacco addiction was related to visual impairments, but one unresolved issue is whether the impairments are related to the many compounds existing in the cigarettes or to the effects of nicotine. On the other hand, nicotine gum can be used as replacement therapy or as a neuroprotective agent for some diseases. The main purpose of this controlled trial is to investigate the effects of nicotine gum on vision. The ENIGMA-Vis trial aims to compare two dosages of nicotine gum (2 and 4 mg) and a placebo gum in a randomized, double-blind, placebo-controlled trial of 100 participants to be allocated into a single group assignment of repeated measures (two studies; N = 50 for each one). Eligibility criteria are healthy non-smokers not diagnosed with substance abuse and without an acute or chronic medical condition. Intervention will last three sessions for each participant with a window frame of 1 week per session. Study outcomes are (1) short-term effects of nicotine gum on contrast sensitivity; (2) short-term effects of nicotine gum on chromatic contrast discrimination; and (3) whether demographics, body mass index, or serum cotinine predicts response of visual processing. This study addresses an important gap in the effects of nicotine on vision. One of the main takeaways of this study is to understand the effects of nicotine on contrast sensitivity and chromatic contrast discrimination. This information will provide a further understanding of how nicotine interacts with early visual processes and help determine how the different components present during smoking can affect vision. Clinical Trial Registration Number: RBR-46tjy3.

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