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1.
Accid Anal Prev ; 134: 105334, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31689573

RESUMO

It has been widely agreed that it is risky for patients with diabetes to drive during hypoglycemia. However, driving during non-hypoglycemia may also bring certain safety hazards for some patients with diabetes. Based on previous studies on diabetes-related to early aging effect, as well as gender differences in health belief and driving behavior, we have hypothesized that middle-aged male drivers with type 2 diabetes, compared with the control healthy ones, may experience a decline in driving performance without awareness. And the decline is caused by impaired perceptual and cognitive driving-related functions. To verify these hypotheses, we recruited 56 non-professional male drivers aged between 40 and 60 (27 patients with type 2 diabetes and 29 healthy controls) to perform a simulated car-following task and finish behavioral tests of proprioception, visual search, and working memory abilities during non-hypoglycemia. They also reported their hypoglycemia experience and perceived driving skills. We found that the patients had equal confidence in their driving skills but worse driving performance as shown in larger centerline deviation (t = 2.83, p = .006), longer brake reaction time (t = 3.77, p = .001) and shorter minimum time-to-collision (t = -3.27, p = .002). Such between-group differences in driving performance could be fully mediated by proprioception, visual search ability, and working memory capacity but not by hypoglycemia experience. Regarding the effect sizes of the mediation, the visual search ability played the most important role, and then followed the working memory and the proprioception. This initial study provides original and first-hand evidence demonstrating that the middle-aged male drivers with type 2 diabetes have deteriorated driving performance, but they are unaware of it. We will also discuss the possible measures to identify people of the highest risk and improve their safety awareness by using the findings of the current study.


Assuntos
Condução de Veículo/psicologia , Cognição/fisiologia , Diabetes Mellitus Tipo 2/complicações , Autoimagem , Estudos de Casos e Controles , Simulação por Computador , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Tempo de Reação/fisiologia
2.
Accid Anal Prev ; 134: 105346, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31710957

RESUMO

Pedestrian distraction is a growing road safety concern worldwide. While there are currently no studies linking distraction and pedestrian crash risk, distraction has been shown to increase risky behaviours in pedestrians, for example, through reducing visual scanning before traversing an intersection. Illuminated in-ground Light Emitting Diodes (LEDs) embedded into pathways are an emerging solution to address the growing distraction problem associated with mobile use while walking. The current study sought to determine if such an intervention was effective in attracting the attention of distracted pedestrians. We conducted a controlled laboratory study (N = 24) to evaluate whether pedestrians detected the activation of flashing LEDs when distracted by a smartphone more accurately and efficiently when the lights were located on the floor compared to a control position on the wall. Eye gaze movements via an eye tracker and behavioural responses via response times assessed the detection of these flashing LEDs. Distracted participants were able to detect the activation of the floor and wall-mounted LEDs with accuracies above 90%. The visual and auditory distraction tasks increased reaction times by 143 and 124 ms, respectively. Even when distracted, performance improved with floor LEDs close to participants, with reaction time improvements by 43 and 159 ms for the LEDs 2 and 1 ms away from the participant respectively. The addition of floor LED lights resulted in a performance similar to the one observed for wall-mounted LEDs in the non-distracted condition. Moreover, participants did not necessarily need to fixate on the LEDs to detect their activation, thus were likely to have detected them using their peripheral vision. The findings suggest that LEDs embedded in pathways are likely to be effective at attracting the attention of distracted pedestrians. Further research needs to be conducted in the field to confirm these findings, and to evaluate the actual effects on behaviour under real-world conditions.


Assuntos
Atenção/fisiologia , Ambiente Construído , Pedestres/psicologia , Smartphone , Adulto , Movimentos Oculares/fisiologia , Feminino , Humanos , Iluminação , Masculino , Tempo de Reação/fisiologia , Segurança , Análise e Desempenho de Tarefas
4.
Int Braz J Urol ; 45(6): 1209-1215, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31808410

RESUMO

PURPOSE: To compare the efficacy and safety of available selective serotonin reuptake inhibi-tors (SSRIs) in order to find the most effective drug with the least number of side effects in treatment of premature ejaculation (PE). MATERIALS AND METHODS: This study was a randomized clinical trial. Four hundred and eighty pati-ents with PE in the 4 groups referred to Imam Reza hospital Tehran, Iran from July 2018 to Fe-bruary 2019 were enrolled in the study. The patients received sertraline 50mg, fluoxetine 20mg, paroxetine 20mg and citalopram 20mg, every 12 hours daily. The intravaginal ejaculatory laten-cy time (IELT) before treatment, fourth and eighth weeks after treatment was recorded by the patient's wife with a stopwatch. RESULTS: Mean IELT before, 4 and 8 weeks after treatment in four groups were: sertraline 69.4±54.3, 353.5±190.4, 376.3±143.5; fluoxetine 75.5±64.3, 255.4±168.2, 314.8±190.4; paroxeti-ne 71.5±69.1, 320.7±198.3, 379.9±154.3; citalopram 90.39±79.3, 279.9±192.1, 282.5±171.1 seconds, respectively. The ejaculation time significantly increased in all groups (p <0.05), but there was no significant difference between the groups (P=0.75). Also, there was no significant difference in drugs side effects between groups (p >0.05). The most common side effects were drowsiness and dyspepsia, which were not severe enough to cause discontinuation of the drug. CONCLUSIONS: All available SSRIs were effective and usually had no serious complications. In patients who did not respond to any of these drugs, other SSRI drugs could be used as a salvage therapy.


Assuntos
Citalopram/uso terapêutico , Fluoxetina/uso terapêutico , Paroxetina/uso terapêutico , Ejaculação Precoce/tratamento farmacológico , Inibidores de Captação de Serotonina/uso terapêutico , Sertralina/uso terapêutico , Adulto , Idoso , Ejaculação/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação/efeitos dos fármacos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
5.
Bratisl Lek Listy ; 120(12): 881-886, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31855045

RESUMO

BACKGROUND: Galangin, a flavonoid compound with acetylcholinesterase inhibitory activity, may improve cognitive functions by enhancing cholinergic transmission. OBJECTIVES: We aimed to investigate the effects of galangin on spatial memory impairment in rats. METHODS: The effects of galangin (50 and 100 mg/kg) and reference anti-dementia drug donepezil (1mg/kg) administrations were examined on memory impairment induced by the muscarinic cholinergic receptor antagonist scopolamine or the nicotinic cholinergic receptor antagonist mecamylamine in the Morris water maze (MWM) test. Hippocampal acetylcholine concentrations were also determined. RESULTS: Galangin 50 and 100 mg/kg significantly decreased the mean distance to platform and increased the time spent in the escape platform quadrant in scopolamine-treated rats. Galangin 100 mg/kg significantly decreased the mean distance to platform and increased the time spent in the escape platform quadrant in mecamylamine-treated rats. The effects of galangin in the MWM were comparable with donepezil. Scopolamine and mecamylamine decreased acetylcholine concentrations, whereas galangin both alone and with mecamylamine or scopolamine administration increased acetylcholine concentrations. CONCLUSION: Galangin improved memory impairment comparable to donepezil and nicotinic and muscarinic receptors may be involved in this effect. Galangin may be considered as a promising flavonoid in the prevention and treatment of memory impairment in Alzheimer's disease and other dementias (Fig. 7,Ref. 37).


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Flavonoides/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Mecamilamina/toxicidade , Escopolamina/toxicidade , Memória Espacial/efeitos dos fármacos , Animais , Aprendizagem da Esquiva/fisiologia , Inibidores da Colinesterase , Donepezila , Flavonoides/administração & dosagem , Aprendizagem em Labirinto/fisiologia , Mecamilamina/efeitos adversos , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia , Escopolamina/efeitos adversos
6.
J Clin Neurophysiol ; 36(6): 452-459, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31688329

RESUMO

It has been well documented that a prepared response can be triggered at short latency following the presentation of a loud acoustic stimulus that evokes a reflexive startle response. Different hypotheses have been proposed for this so-called "StartReact" effect, although there is still much debate surrounding the physiological mechanisms involved in the observed reduction in reaction time (RT). In this review, we outline the various neurophysiological explanations underlying the StartReact effect and summarize the data supporting, and at times opposing, each possibility. Collectively, the experimental results do not unequivocally support a single explanation and we suggest the most parsimonious mechanism may involve a hybrid framework involving a distribution of neural pathways. Specifically, we propose that multiple node networks at the cortical, brainstem, and spinal levels are involved in response preparation and initiation, and the relative contributions of these structures depends on the type of stimulus delivered and the type of movement required. This approach may lead to greater understanding of the pathways involved in response preparation, initiation, and execution for both healthy and motor disordered populations.


Assuntos
Tempo de Reação/fisiologia , Reflexo de Sobressalto/fisiologia , Estimulação Acústica/métodos , Feminino , Humanos , Masculino , Movimento/fisiologia
7.
Exp Psychol ; 66(5): 361-367, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31696793

RESUMO

A long-standing debate in the Stroop literature concerns whether the way we respond to the color dimension determines how we process the irrelevant dimension, or whether word processing is purely stimulus driven. Models and findings in the Stroop literature differ in their predictions about how response modes (e.g., responding manually vs. vocally) affect how the irrelevant word is processed (i.e., phonologically, semantically) and the interference and facilitation that results, with some predicting qualitatively different Stroop effects. Here, we investigated whether response mode modifies phonological facilitation produced by the irrelevant word. In a fully within-subject design, we sought evidence for the use of a serial print-to-speech prelexical phonological processing route when using manual and vocal responses by testing for facilitating effects of phonological overlap between the irrelevant word and the color name at the initial and final phoneme positions. The results showed phoneme overlap leads to facilitation with both response modes, a result that is inconsistent with qualitative differences between the two response modes.


Assuntos
Tempo de Reação/fisiologia , Semântica , Teste de Stroop/normas , Adulto , Feminino , Humanos , Linguagem , Masculino
8.
Sleep Med Clin ; 14(4): 463-468, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31640874

RESUMO

This article reports on sleepiness, drowsiness, tiredness, and fatigue. An assessment of sleepiness can be done with electroencephalograms, electrooculograms, and electromyograms in validated tests, such as the multiple sleep latency test and the maintenance of wakefulness test. These 2 tests serve as references for quantitative assessment of daytime sleepiness and drowsiness. Correlates for sleepiness, such as reaction time tests, can be used but are less reliable. Questionnaires are self-administered and popular measures for perceived sleepiness. Driver drowsiness assessment is an important part of sleep laboratory testing, because European Union regulations require assessments due to risk of accidents in patients with sleep disorders.


Assuntos
Transtornos do Sono-Vigília/diagnóstico , Sonolência , Condução de Veículo , Eletroencefalografia , Eletroculografia , Humanos , Polissonografia , Tempo de Reação
9.
Nat Commun ; 10(1): 4798, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641118

RESUMO

Inhibitory control is fundamental to children's self-regulation and cognitive development. Here we investigate cortical-basal ganglia pathways underlying inhibitory control in children and their adult-like maturity. We first conduct a comprehensive meta-analysis of extant neurodevelopmental studies of inhibitory control and highlight important gaps in the literature. Second, we examine cortical-basal ganglia activation during inhibitory control in children ages 9-12 and demonstrate the formation of an adult-like inhibitory control network by late childhood. Third, we develop a neural maturation index (NMI), which assesses the similarity of brain activation patterns between children and adults, and demonstrate that higher NMI in children predicts better inhibitory control. Fourth, we show that activity in the subthalamic nucleus and its effective connectivity with the right anterior insula predicts children's inhibitory control. Fifth, we replicate our findings across multiple cohorts. Our findings provide insights into cortical-basal ganglia circuits and global brain organization underlying the development of inhibitory control.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Adolescente , Adulto , Gânglios da Base/fisiologia , Córtex Cerebral/fisiologia , Criança , Bases de Dados Factuais , Humanos , Imagem por Ressonância Magnética , Tempo de Reação/fisiologia , Núcleo Subtalâmico/fisiologia , Adulto Jovem
10.
Mymensingh Med J ; 28(4): 925-929, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31599262

RESUMO

Blood pressure in our body is finely regulated through autonomic nervous system and cardiac centers and studies established that parasympathetic dominance exerted by slow deep breathing decreases blood pressure. Reaction time is an estimate of the subject's capacity for inhibiting pre-potent motor responses. Decreased reaction time indicates greater alertness, faster information processing and less distractibility. Nevertheless, there has been conflicting results about the effect of deep slow breathing on reaction time The present research targeted a community based cross sectional observational study (n=80, age=17-70 years) performed in Lalitpur Municipality, Ward number-14, Nepal from May 2019 to June 2019, to observe the immediate effect of slow deep breathing exercise on blood pressure and reaction time by using online visual reaction time test. Volunteers performed the slow breathing exercise (approximately 4seconds inhalation and 6 seconds exhalation) in Sukhasana for 5 minutes. Base-line and post-slow-breathing blood pressure and visual reaction time was recorded and compared. Decrease in systolic and diastolic pressure was recorded in all, but statistically insignificant. Among the whole study population, significant decrease (p<0.001) in reaction time was noted (90.35±13.96 msVs 76.68±9.90 ms). Among male subjects of age-group 17-28 years, and 50-70 years, significant decrease in reaction time was noted (p<0.05) whereas, among the female subjects of all age groups, reaction time decreased significantly (p<0.05). Decrease in reaction time signifies improved central neuronal processing activity. This may be due to greater arousal, faster information processing, and ability to ignore or inhibit extraneous stimuli. Hence, regular practice of slow deep breathing exercise may be beneficial to lower blood pressure and to improve concentration.


Assuntos
Pressão Sanguínea , Exercícios Respiratórios , Estudos Transversais , Feminino , Frequência Cardíaca , Humanos , Masculino , Nepal , Tempo de Reação
11.
Nat Commun ; 10(1): 4704, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624264

RESUMO

The subjective sense of certainty, or confidence, in ambiguous sensory cues can alter the interpretation of reward feedback and facilitate learning. We trained rats to report the orientation of ambiguous visual stimuli according to a spatial stimulus-response rule that must be learned. Following choice, rats could wait a self-timed delay for reward or initiate a new trial. Waiting times increase with discrimination accuracy, demonstrating that this measure can be used as a proxy for confidence. Chemogenetic silencing of BLA shortens waiting times overall whereas ACC inhibition renders waiting times insensitive to confidence-modulating attributes of visual stimuli, suggesting contribution of ACC but not BLA to confidence computations. Subsequent reversal learning is enhanced by confidence. Both ACC and BLA inhibition block this enhancement but via differential adjustments in learning strategies and consistent use of learned rules. Altogether, we demonstrate dissociable roles for ACC and BLA in transmitting confidence and learning under uncertainty.


Assuntos
Complexo Nuclear Basolateral da Amígdala/fisiologia , Comportamento de Escolha/fisiologia , Giro do Cíngulo/fisiologia , Reversão de Aprendizagem/fisiologia , Incerteza , Animais , Condicionamento Operante/fisiologia , Masculino , Estimulação Luminosa , Ratos Long-Evans , Tempo de Reação/fisiologia , Recompensa
12.
Artigo em Inglês | MEDLINE | ID: mdl-31547412

RESUMO

Human neuropsychological reactions and brain activities when driving electric vehicles (EVs) are considered as an issue for traffic and public safety purposes; this paper examined the effect of the static magnetic field (SMF) derived from EVs. A lane change task was adopted to evaluate the driving performance; and the driving reaction time test and the reaction time test were adopted to evaluate the variation of the neuro-psychological cognitive functions. Both the sham and the real exposure conditions were performed with a 350 µT localized SMF in this study; 17 student subjects were enrolled in this single-blind experiment. Electroencephalographs (EEGs) of the subjects were adopted and recorded during the experiment as an indicator of the brain activity for the variations of the driving performance and of the cognitive functions. Results of this study have indicated that the impact of the given SMF on both the human driving performance and the cognitive functions are not considerable; and that there is a correlation between beta sub-band of the EEGs and the human reaction time in the analysis.


Assuntos
Condução de Veículo/estatística & dados numéricos , Automóveis/classificação , Cognição/efeitos da radiação , Campos Magnéticos/efeitos adversos , Tempo de Reação/efeitos da radiação , Feminino , Hong Kong , Humanos , Masculino , Método Simples-Cego , Adulto Jovem
13.
Artigo em Inglês | MEDLINE | ID: mdl-31547477

RESUMO

Advances in experimental psychology have provided evidence for the presence of attentional and approach biases in individuals with substance use disorders. Traditionally, reaction time tasks, such as the Stroop or the Visual Probe Task, are commonly used in the assessment of attention biases. The Visual Probe Task has been criticized for its poor reliability, and other research has highlighted that variations remain in the paradigms adopted. However, a gap remains in the published literature, as there have not been any prior studies that have reviewed stimulus timings for different substance use disorders. Such a review is pertinent, as the nature of the task might affect its effectiveness. The aim of this paper was in comparing the different methods used in the Visual Probe Task, by focusing on tasks that have been used for the most highly prevalent substance disorders-that of opiate use, cannabis use and stimulant use disorders. A total of eight published articles were identified for opioid use disorders, three for cannabis use disorders and four for stimulant use disorders. As evident from the synthesis, there is great variability in the paradigm adopted, with most articles including only information about the nature of the stimulus, the number of trials, the timings for the fixation cross and the timings for the stimulus set. Future research examining attentional biases among individuals with substance use disorders should take into consideration the paradigms that are commonly used and evaluate the optimal stimulus and stimulus-onset asynchrony timings.


Assuntos
Viés de Atenção , Tempo de Reação , Transtornos Relacionados ao Uso de Substâncias/patologia , Humanos , Reprodutibilidade dos Testes , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Percepção Visual
14.
J Sports Sci ; 37(23): 2691-2701, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31526108

RESUMO

This study investigated effects of total sleep deprivation on self-paced endurance performance, and heart rate (HR) indices of athletes' "readiness to perform". Endurance athletes (n = 13) completed a crossover experiment comprising a normal sleep (NS) and sleep deprivation (SD) condition. Each required completion of an endurance time-trial (TT) on consecutive days (D1, D2) separated by normal sleep or total sleep deprivation. Finishing time, perceived exertion (RPE), mood, psychomotor vigilance (PVT), and HR responses were assessed. Time on D2 of SD was 10% slower than D2 of NS (64 ± 7 vs 59 ± 4 min, P < 0.01), and 11% slower than D1 of SD (58 ± 5 min, P < 0.01). Subjective to objective (RPE:mean HR) intensity ratio was higher on D2 of SD compared with D2 of NS and D1 of SD (P < 0.01). Mood disturbance and PVT mean response time increased on D2 of SD compared with D2 of NS and D1 of SD. Anaerobic threshold and change in TT time were correlated (R = -0.73, P < 0.01). Sleep helps to optimise endurance performance. Subjective to objective intensity ratios appear sensitive to effects of sleep on athletes' readiness. Research examining more subtle sleep manipulation is required.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Resistência Física/fisiologia , Privação do Sono/fisiopatologia , Actigrafia/instrumentação , Adulto , Afeto/fisiologia , Ciclismo/psicologia , Estudos Cross-Over , Teste de Esforço , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Tempo de Reação/fisiologia , Dispositivos Eletrônicos Vestíveis
15.
Nat Commun ; 10(1): 3969, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481671

RESUMO

Analyses of idealized feedforward networks suggest that several conditions have to be satisfied in order for activity to propagate faithfully across layers. Verifying these concepts experimentally has been difficult owing to the vast number of variables that must be controlled. Here, we cultured cortical neurons in a chamber with sequentially connected compartments, optogenetically stimulated individual neurons in the first layer with high spatiotemporal resolution, and then monitored the subthreshold and suprathreshold potentials in subsequent layers. Brief stimuli delivered to the first layer evoked a short-latency transient response followed by sustained activity. Rate signals, carried by the sustained component, propagated reliably through 4 layers, unlike idealized feedforward networks, which tended strongly towards synchrony. Moreover, temporal jitter in the stimulus was transformed into a rate code and transmitted to the last layer. This novel mode of propagation occurred in the balanced excitatory-inhibitory regime and is mediated by NMDA-mediated receptors and recurrent activity.


Assuntos
Neurônios/fisiologia , Transdução de Sinais , Potenciais de Ação , Animais , Células Cultivadas , Córtex Cerebral/citologia , Feminino , Masculino , Camundongos , Neurônios/citologia , Optogenética , Tempo de Reação/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia
16.
Nat Commun ; 10(1): 4030, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492881

RESUMO

The ability to track the statistics of our surroundings is a key computational challenge. A prominent theory proposes that the brain monitors for unexpected uncertainty - events which deviate substantially from model predictions, indicating model failure. Norepinephrine is thought to play a key role in this process by serving as an interrupt signal, initiating model-resetting. However, evidence is from paradigms where participants actively monitored stimulus statistics. To determine whether Norepinephrine routinely reports the statistical structure of our surroundings, even when not behaviourally relevant, we used rapid tone-pip sequences that contained salient pattern-changes associated with abrupt structural violations vs. emergence of regular structure. Phasic pupil dilations (PDR) were monitored to assess Norepinephrine. We reveal a remarkable specificity: When not behaviourally relevant, only abrupt structural violations evoke a PDR. The results demonstrate that Norepinephrine tracks unexpected uncertainty on rapid time scales relevant to sensory signals.


Assuntos
Nível de Alerta/fisiologia , Potenciais Evocados Auditivos/fisiologia , Desempenho Psicomotor/fisiologia , Pupila/fisiologia , Tempo de Reação/fisiologia , Som , Estimulação Acústica , Adulto , Encéfalo/metabolismo , Encéfalo/fisiologia , Feminino , Humanos , Masculino , Norepinefrina/metabolismo , Incerteza , Adulto Jovem
17.
J. optom. (Internet) ; 12(3): 192-197, jul.-sept. 2019. tab, graf
Artigo em Inglês | IBECS | ID: ibc-185370

RESUMO

Purpose: Visual evoked potentials (VEPs) provide important diagnostic information related to the functional integrity of the visual pathways. The aim of this study was to establish normative values of different components of pattern reversal VEPs on Iranian normal adult subjects. Methods: Monocular and binocular pattern reversal VEPs were recorded on 59 healthy participants (22.55 ± 3.79 years old) using the Roland RETI system for two check sizes of 15 and 60 min of arc. The measured VEP components were the latencies of N75, P100, N135 and amplitude of N75-P100. Results: Repeated measures ANOVA showed that viewing eye condition has a significant impact on the amplitude of N75-P100 (P < 0.001, F = 13.89). Also, the effect of check size on the latencies of N75, P100, N135, amplitude of N75-P100 (P ≤ 0.010), as well as the intraocular difference of P100 latency and amplitude N75-P100 (P = 0.007) was significant. More specifically, the amplitude of N75-P100 in both check sizes significantly differed between gender groups (P < 0.023). Conclusion: According to the results of this study, VEPs components are affected by the stimulus size, monocular and binocular recording conditions and gender. Therefore, it is necessary to determine the normative values of VEPs in each population, so that the results could be used in clinical studies


Objetivo: Los potenciales evocados visuales (PEV) aportan información diagnóstica importante relacionada con la integridad funcional de las vías visuales. El objetivo de este estudio fue establecer los valores normativos de los diferentes componentes de la reversión del patrón de PEV en adultos normales iraníes. Métodos: Se registraron los valores de reversión monocular y binocular del patrón de PEV en 59 participantes sanos (22,55 ± 3,79 años), utilizando el sistema Roland RETI para dos tamaños de comprobación de 15 y 60 min de arco. Los componentes medidos de PEV fueron las latencias de N75, P100, N135 y la amplitud de N75-P100. Resultados: La repetición de las medidas ANOVA reflejó que la situación del ojo de visión tiene un impacto significativo sobre la amplitud de N75-P100 (P < 0,001, F = 13,89). De igual modo, el efecto del tamaño de la comprobación de las latencias de N75, P100, N 135, la amplitud de N75-P100 (P ≤ 0,010), así como la diferencia intraocular de la latencia de P100 y la amplitud de N75-P100 (P = 0,007) fue significativo. Más específicamente, la amplitud de N75-P100 en ambos tamaños de comprobación difirió considerablemente entre los grupos de sexos (P < 0,023). Conclusión: Con arreglo a los resultados de este estudio, los componentes de los PEV se ven afectados por el tamaño del estímulo, las situaciones del registro monocular y binocular, y el sexo. Por tanto, es necesario determinar los valores normativos de los PEV en cada población, para poder utilizar los resultados en estudios clínicos


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Potenciais Evocados Visuais/fisiologia , Visão Binocular/fisiologia , Vias Visuais/fisiologia , Análise de Variância , Irã (Geográfico) , Tempo de Reação , Valores de Referência , Visão Monocular/fisiologia
18.
Acta Psychol (Amst) ; 199: 102891, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31400651

RESUMO

Cognitive control enables optimal biasing of attention, perception, and actions in the service of mental or behavioral goals. To understand the variability of applied cognitive control, we need to unravel the relation between two underlying mechanisms: proactive and reactive modes. During proactive cognitive control, goal-relevant information is selected before the occurrence of a cognitively demanding event, and is actively maintained for as long as required by the task. During reactive mode, cognitive control is transiently activated only after the cognitively demanding event has occurred. Mechanistically, proactive and reactive control modes may be at least semi-independent and engaged simultaneously, but this has so far not been demonstrated empirically. Situational demands and an individual's cognitive capacity and motivation may bias behavior towards one or the other mode. Reward induces more proactive processing in the AX-CPT task, whereas context load induces reactive processing. We combined these manipulations to investigate the extent to which proactive and reactive control modes can operate independently and simultaneously. The results replicated already published effects of reward incentives and context load. Most importantly, these effects were essentially independent of each other, suggesting that proactive and reactive cognitive control modes depend on separate information-processing and neural mechanisms. The results also show that while proactive processing is influenced by reward, reactive processing seems independent of such factor. These findings have implications for our understanding of the structure of cognitive control and cognitive motivation, and are relevant for the design of interventions to improve cognitive control in various developmental and neuropsychiatric groups.


Assuntos
Cognição/fisiologia , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Recompensa , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Motivação/fisiologia , Adulto Jovem
19.
Psychol Aging ; 34(6): 805-820, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31414857

RESUMO

In hybrid foraging tasks, observers search visual displays, so called patches, for multiple instances of any of several types of targets with the goal of collecting targets as quickly as possible. Here, targets were photorealistic objects. Younger and older adults collected targets by mouse clicks. They could move to the next patch whenever they decided to do so. The number of targets held in memory varied between 8 and 64 objects, and the number of items (targets and distractors) in the patches varied between 60 and 105 objects. Older adults foraged somewhat less efficiently than younger adults due to a more exploitative search strategy. When target items became depleted in a patch and search slowed down, younger adults acted according to the optimal foraging theory and moved on to the next patch when the instantaneous rate of collection was close to their average rate of collection. Older adults, by contrast, were more likely to stay longer and spend time searching for the last few targets. Within a patch, both younger and older adults tended to collect the same type of target in "runs." This behavior is more efficient than continual switching between target types. Furthermore, after correction for general age-related slowing, RT × set size functions revealed largely preserved attention and memory functions in older age. Hybrid foraging tasks share features with important real-world search tasks. Differences between younger and older observers on this task may therefore help to explain age differences in many complex search tasks of daily life. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Envelhecimento , Atenção/fisiologia , Envelhecimento Cognitivo , Percepção de Forma/fisiologia , Memória de Curto Prazo/fisiologia , Memória , Reconhecimento Visual de Modelos/fisiologia , Percepção Visual/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Vida , Masculino , Pessoa de Meia-Idade , Motivação , Estimulação Luminosa/métodos , Tempo de Reação , Adulto Jovem
20.
Dement Geriatr Cogn Disord ; 47(4-6): 281-288, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31408867

RESUMO

BACKGROUND: Although simple reaction time (SRT) slowing is associated with dementia in Alzheimer's disease (AD), its presence in individuals with mild cognitive impairment (MCI) is subject to debate. OBJECTIVE: The aim of this study was to perform a systematic review and meta-analysis of the literature data on SRT slowing in MCI. METHODS: Publications with data on SRT, age, and educational level in participants with MCI were included. After calculating the log SRT and its variance for each study, we took interstudy heterogeneity into account by conducting a random effects (restricted maximum likelihood estimation) meta-analysis. RESULTS: The 7 selected studies featured a total of 327 participants with MCI and 468 healthy controls (HCs). The mean age was 68.2 years for participants with MCI and 72.3 years for HCs. The weighted mean Mini-Mental State Examination score was 26.4 in the MCI group, and 28.4 in the HC group. The mean SRT was significantly (p = 0.0217) longer in the MCI group (by 11%) than in the HC group. CONCLUSION: This meta-analysis showed that SRTs are longer in individuals with MCI. Further studies are needed to determine the mechanism of SRT slowing, its anatomical correlates, and a threshold value for diagnosing prodromal AD.


Assuntos
Doença de Alzheimer/psicologia , Tempo de Reação , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/psicologia , Diagnóstico Precoce , Humanos , Pessoa de Meia-Idade
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