Human perception of flicker-fused letters that are luminance balanced.

The Talbot-Plateau law specifies what combinations of flash frequency, duration, and intensity will yield a flicker-fused stimulus that matches the brightness of a steady stimulus. It has proven to be remarkably robust in its predictions, and here we provide additional support though the use of a contrast discrimination task. However, we also find that the visual system can register flicker-fused letters when the combination of frequency and duration is relatively low. The letters are recognized even though they have the same physical luminance as background. We hypothesize that the letters elicit synchronous oscillations that encode for stimulus attributes, which prevents the letter from blending into the background.

Flicker and reading speed: Effects on individuals with visual sensitivity.

Flicker and patterns of stripes in the modern environment can evoke visual illusions, discomfort migraine, and seizures. We measured reading speed while striped and less striped texts were illuminated with LED lights. In Experiment 1, the lights flickered at 60 Hz and 120 Hz compared to 60 kHz (perceived as steady light). In Experiment 2, the lights flickered at 60 Hz or 600 Hz (at which frequency the phantom array is most visible), and were compared to continuous light. Two types of text were used: one containing words with high horizontal autocorrelation (striped) and another containing words with low autocorrelation (less striped). We measured the number of illusions participants saw in the Pattern Glare (PG) Test. Overall, reading speed was slowest during the 60 Hz and 600 Hz flicker and was slower when reading the high autocorrelation text. Interestingly, the low PG group showed greater effects of flicker on reading speed than the high PG group, which tended to be slower overall. In addition, reading speed in the high PG group was reduced when the autocorrelation of the text was high. These findings suggest that uncomfortable visual environments reduce reading efficiency, the more so in individuals who are visually sensitive.

The speed of sight: Individual variation in critical flicker fusion thresholds.

The critical flicker fusion threshold is a psychophysical measure commonly used to quantify visual temporal resolution; the fastest rate at which a visual system can discriminate visual signals. Critical flicker fusion thresholds vary substantially among species, reflecting different ecological niches and demands. However, it is unclear how much variation exists in flicker fusion thresholds between healthy individuals of the same species, or how stable this attribute is over time within individuals. In this study, we assessed both inter- and intra-individual variation in critical flicker fusion thresholds in a cohort of healthy human participants within a specific age range, using two common psychophysical methods and three different measurements during each session. The resulting thresholds for each method were highly correlated. We found a between-participant maximum difference of roughly 30 Hz in flicker fusion thresholds and we estimated a 95% prediction interval of 21 Hz. We used random-effects models to compare between- and within-participant variance and found that approximately 80% of variance was due to between-individual differences, and about 10% of the variance originated from within-individual differences over three sessions. Within-individual thresholds did not differ significantly between the three sessions in males, but did in females (P<0.001 for two methods and P<0.05 for one method), indicating that critical flicker fusion thresholds may be more variable in females than in males.

Critical flicker fusion in patients with epilepsy under antiseizure medication.

OBJECTIVE: Critical flicker frequency (CFF) and flicker frequency (FF) are used as indicators for the neurotoxic adverse events of drugs in pharmacology. In this pilot study, we investigated whether patients with epilepsy (PWE) treated with various antiseizure medications (ASM) had significantly different CFFs compared with healthy controls. In addition, we investigated the appropriateness of CFF as an objective measurement tool in PWE who reported adverse events according to the adverse event profile (AEP). METHODS: Patients receiving regular antiseizure treatment at our center, along with healthy controls, were included in this study. Clinical neurotoxic symptoms, AEP scores, and serum ASM levels were assessed in the PWE group. We used a CFF device that produced a red-black, green-black, blue-black, or white-black flicker. CFF and FF were compared between PWE and healthy controls. In PWE, the correlation of alterations in CFF and FF with AEP results and through ASM serum concentrations was calculated. RESULTS: A total of 33 PWE and 20 healthy controls participated in the study. Except for two light modalities, CFF and FF were significantly reduced in PWE compared with controls. CFF and FF did not differ significantly between PWE with AEP scores >44 points and those with lower scores. CFF and FF levels did not correlate with changes in AEP scores, serum concentrations, or doses. SIGNIFICANCE: CFF and FF distinguished PWE with ASM from healthy controls. No clinically relevant differentiation was detected in the heterogenous PWE group. To investigate whether CFF and FF may serve as subtle indicators of neurotoxicity or specific modes of action, additional studies are needed in more homogenous PWE groups.

Relationship between Ocular Fatigue and Use of a Virtual Reality Device

PURPOSE: To investigate ocular fatigue after the use of a head-mounted display (HMD)-type virtual reality device.METHODS: Healthy adult volunteers were examined for ocular fatigue before and after watching videos for 10 min with an HMD-type virtual reality device. Subjective ocular fatigue was measured using a questionnaire. Objective fatigue was measured using the critical flicker fusion frequency (CFF), high frequency component of accommodative microfluctuation, and accommodation amplitude. The accommodation amplitude was measured using the push-up method and the dynamic measurement mode of the autorefractometer. Changes in the spherical equivalent were also measured.RESULTS: The questionnaire-based subjective ocular fatigue increased (p = 0.020) after use of the HMD device. In the dominant eye, the high frequency component of accommodative microfluctuation increased (p < 0.05). The accommodation amplitude using the push-up method was decreased in the nondominant eye (p = 0.007), and temporary myopia was observed (p < 0.05). However, there was no increase in ocular fatigue in the CFF or the accommodation amplitude using the dynamic measurement mode, which showed no significant difference before and after using the HMD device (p > 0.05).CONCLUSIONS: A subjective test and some objective tests suggested that use of the HMD-type virtual reality display increased ocular fatigue. However, no increase in ocular fatigue was measured using CFF nor in the accommodation amplitude using the dynamic measurement mode which was a limitation of the study. More studies with the aim to alleviate ocular fatigue after using HMD-type virtual reality devices are therefore needed.

Assessment of Sleep Deprivation and Fatigue Among Chemical Transportation Drivers in Chonburi, Thailand

BACKGROUND: Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined. METHODS: A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument. RESULTS: Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score. CONCLUSION: Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work–rest model should be considered to improve productivity, driver retention, and road safety.

La visión binocular en el glaucoma / Binocular vision in glaucoma

Objetivo: Describir posibles alteraciones de la visión binocular en sujetos afectados de glaucoma primario de ángulo abierto (GPAA). Método: Estudio de diseño transversal. Se incluyó a 58 sujetos glaucomatosos, 76 hipertensos oculares y 82 controles. En estos pacientes se estudiaron los ángulos de foria, las amplitudes de fusión (AF) en visión lejana y cercana, el punto próximo de convergencia (PPC), la supresión cercana y lejana mediante el test de Worth y la estereoagudeza según los tests de Titmus y TNO. Resultados: Los glaucomatosos presentaron un aumento significativo de los ángulos de foria sobre todo en visión cercana, frente a los hipertensos y controles (p = 0,000). Las AF estaban reducidas, principalmente la cercana, con respecto a hipertensos y controles (p = 0,000). El PPC de los glaucomatosos fue mayor que el de los otros dos grupos (p = 0,000). No se hallaron diferencias en el test de la supresión cercana entre los tres grupos (p = 0,682), pero sí en la lejana de los glaucomas con respecto de los hipertensos (OR = 3,867; IC del 95%, 1,260 11,862; p = 0,008) y a los controles (OR = 5,831; IC del 95%, 2,229 15,252; p = 0,000). La estereoagudeza de los glaucomatosos se encontraba reducida en ambos tests (p = 0,001). Conclusiones: El GPAA se asocia principalmente a un aumento de la exoforia cercana, a una disminución de la AF en la visión cercana, a un alejamiento del PPC, a la aparición de supresión central en visión lejana y a una pérdida de estereoagudeza. Estas alteraciones no parecen ser precoces, ya que no se observaron en los hipertensos frente a los controles (AU)

Objective: To describe the possible impairment of binocular vision in primary open angle glaucoma (POAG) patients. Method: A cross-sectional study was conducted on 58 glaucoma patients, 76 ocular hypertensives and 82 normal subjects. They were examined with a battery of binocular tests consisting of the measurement of phoria angles, amplitudes of fusion (AF), near point of convergence (NPC) assessment, an evaluation of suppression (Worth test), stereoacuity according to Titmus, and TNO tests. Results: The patients with glaucoma showed significantly increased phoria angles, especially in near vision, compared with the ocular hypertensives and controls (P=0.000). AF were reduced mainly in near distances compared to hypertensives and controls (P=0.000). The NPC of glaucoma was higher than the other two groups (P=.000). No differences were found in the near-distance suppression test between the three groups (P=.682), but there were differences in the distance vision of patients with glaucoma compared to hypertensives (OR=3.867, 95% CI; 1.260-11.862; P=0.008) and controls (OR= 5.831, 95% CI; 2.229-15.252; P=0.000). The stereoacuity of patients with glaucoma was reduced in both tests (P=0.001). Conclusions: POAG is mostly associated with, an increased exophoria in near vision, a decreased AF in near vision, a far-distance NPC, central suppression in far-vision, and a loss of stereoacuity. These changes do not seem to appear early as they were not observed in hypertensive patients versus controls (AU)

Comparison of Effects of Alcohol on Daytime Sleepiness, Psychomotor Performance, and Subjective Response according to ALDH2 Genotype in Healthy Young Men: A Double-Blind Placebo-Controlled Crossover Study / 대한정신약물학회지

OBJECTIVE: This study aimed to investigate the effects of alcohol on daytime sleepiness, psychomotor performance, and subjective response in healthy young men with different ALDH2 genotypes. METHODS: A total of 24 males, half with the active ALDH2*1/*1 and the rest with inactive the ALDH2*1/*2, were selected through genotyping. In a double-blind, placebo-controlled crossover design, each subject consumed either a 0.5 g/kg dose of alcohol or placebo in the morning on two separate occasions, a week apart. Multiple Sleep Latency Test, a battery of psychomotor tests (Critical Flicker Fusion Threshold, Choice Reaction Time, Compensatory Tracking Task, Digit Symbol Substitution), questionnaire for subjective response and modified Epworth Sleepiness Scale were administered. RESULTS: Daytime sleep latency was significantly decreased after alcohol intake in the morning compared to placebo, and the decrease was much greater in subjects with ALDH2*1/*2 than in subjects with ALDH2*1/*1. Psychomotor function was significantly impaired after alcohol intake in the morning compared to placebo, in subjects with ALDH2*1/*2. Subjective response was significantly negative or intense after alcohol intake in the morning, compared to placebo, in subjects with ALDH2*1/*2. Subjective daytime sleepiness was significantly increased after alcohol intake compared to placebo, in subjects with ALDH2*1/*2. CONCLUSION: These results supported that ALDH2 polymorphism might be one of important factors in determining the effects of alcohol on the various psychobehavioural functions as well as on patterns of alcohol use.

Acute Effect of Single Oral Administration of Nefazodone and Trazodone of Psychomotor Performance: A Duble-Blind Cross-Over Comparison in Healthy Volunteers / 대한정신약물학회지

OBJECTIVE: New antidepressant, nefazodone is classified as a serotonin -2 antagonist/reuptake inhibitor like old antidepressant, trazodone. Nefazodone, however, differs from trazodone in that it lacks anti-histaminergic properties and in that it has some norepinephrine reuptake inhibitory properties. These differences may account for the differences between the two drugs in the side effect profiles. This study was conducted to compare the acute effects of nefazodone on the psychomotor performance with those of trazodone. METHODS: The subjects were 12 healthy male volunteers aged between 20-40 years. A single, oral starting dose of nefazodone or trazodone was administered in a double-blind, randomized latin-square design with a 1-week interval between each drug switch. Psychomotor performances were assessed at 1 hour before and at 2 hours after administration of nefazodone 50 mg, nefazodone 100 mg or trazodone 50 mg. The measures of psychomotor performance included Vienna Determination Unit for complex choice reaction time, Critical Flicker Fusion Test, and Grooved Pegboard Test. RESULTS: In the Vienna Determination Unit, when 'within drug effect' (pre- vs. post-medication) was analyzed, nefazodone 100 mg decreased complex choice reaction time in both subtest 2 and subtest 3. Nefazodone 50 mg also decreased the reaction time in subtest 3 but not in subtest 2 which was more difficult and demanding task than subtest 3. On the other hand, no significant changes in the reaction time were observed with trazodone 50 mg in either subtest 2 or subtest 3. When 'between drug effect' was analyzed, however, the differences between drugs were not found to reach statistically significant level. No significant 'between drug effect' or 'within drug effect' was observed in Critical Flicker Fusion Test and Grooved Pegboard Test. CONCLUSION: Although the differences between nefazodone and trazodone did not reach statistically significant level, the results on the complex choice reaction time suggest that al least a single starting dose of nefazodone up to 100 mg does not impair psychomotor performances and it might have a less detrimental effect than trazodone on the psychomotor performance.

Relation of psychosocial stress, eye strain, and critical flicker fusion of VDT workers

To clarify that the psychosocial factors affect the eye strain of the VDT workers, self-reporting questionnaire about eye strain, critical flicker fusion(CFF), and 12-item version of General Health Questionnaire(GHQ) were carried out to 13 female VDT workers who have done the electronic editing and 10 female controls who were nurses in one hospital. The sum of eye symptoms of VDT workers were significantly higher than controls, but CFF of both groups were not different. And the sum of eye symptoms and CFF were not correlated. High stress group(sum of GHQ > 3) shows significantly more eye symptoms than low stress group. This result suggest that the psychosocial factors could affect the eye strain of VDT workers.

The Acute Pharmacodynamic Effects of Venlafaxine and Mirtazapine on Psychomotor Performance, Motor Activity, and Daytime Sleepiness / 대한정신약물학회지

OBJECTIVE: For the optimal use of antidepressants, it is important to consider the behavioral effects of drugs affecting the real lives of depressed patients, as there is little difference in therapeutic effects between drugs. The aim of this study was to determine the acute pharmacodynamic effects of two recently introduced antidepressants, venlafaxine and mirtazapine, on psychomotor performance, motor activity and daytime sleepiness. METHODS: Twelve healthy male volunteers received a single dose of venlafaxine 37.5 mg, mirtazapine 15 mg or amitriptyline 25 mg (positive control) at one-week intervals in a double-blind, placebo-controlled, crossover design. Volunteers wore an actigraph on their non-dominant wrist for the duration of each test day. A battery of psychomotor tests was performed prior to dosing and at 2 and 6 h post-dose. Subjective daytime sleepiness was also assessed at the end of each test day. RESULTS: Venlafaxine did not affect psychomotor performance, motor activity and daytime sleepiness. Mirtazapine decreased thresholds in critical flicker fusion frequency, increased reaction times in choice reaction tests, and increased peripheral reaction times in compensatory tracking tests. It also caused significant daytime sleepiness and decreased motor activity. CONCLUSION: The differences in the behavioral effect profiles presented in this study should assist in the selection or scheduling of antidepressants.

Psychiatric Function and Quality of Life of Workers with Long-Term Exposure to Organic Solvents / 신경정신의학

OBJECTIVES: The aim of this study was to evaluate the psychiatric function and quality of life of the chemical workers who had been exposed to long-term, low-level organic solvents in the Y industrial complex. METHODS: A total of 144 male workers, of whom 82 were in the exposed group and 60 in the unexposed-control group, were evaluated by using Symptom Checklist-90-R(SCL-90-R), series of neuropsychological tests(critical flicker fusion threshold, CFFT); choice reaction time, CRT; compensatory tracking task, CTT); digit symbol substitution test, DSS), and the Korean version of the SmithKline Beecham Quality Of Life scale(KvSBQOL). For the statistical analyses, comparisons of the means of the two groups were performed for each variable with two-tailed t-test as well as ANCOVA including age and education as covariates. RESULTS: For the SCL-90-R, the nine symptom scales and the three global indices were clinically within normal range in both groups. However, the scores on the symptom scales of 'somatization', 'depression', 'hostility' and 'phobic anxiety', and those on the global indices of 'global severity index' and 'positive symptom total', were significantly higher in the exposed group than in the unexposed group. In terms of the neuropsychological function and the quality of life, there wes no significant difference between the two groups. CONCLUSIONS: These findings suggested that the long-term exposure to mixed organic solvents, even at the low level below the permissible exposure limit, might induce some psychiatric problems.

Effects of Alcohol on Neurocognitive Function, Psychomotor Performance and Subjective Response in Koreans with Different ALDH2 Genotypes

OBJECTIVE: The purpose of this study was to evaluated the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. METHOD: A total of 24 males, half with active ALDH2*1/2*1 and the other with inactive ALDH2*1/2*1, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time(CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. RESULTS: The major results are as follows. 1) BACs in inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. CONCLUSIONS: These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

Effects of Nemonapride on Cognitive and Psychomotor Performance and Sedation in Normal Adults: A Comparison with Chlorpromazine, Haloperidol and Placebo / 대한정신약물학회지

This study was done to compare the effects of nemonapride on cognitive and psychomotor performance and sedation with those of classical antipsychotics in normal adults. Single doses of three antipsychotics (chlorpromazine 50mg, haloperidol 2mg and nemonapride 3mg) and placebo were given to 8 healthy male volunteers at weekly intervals, in a double-blind Latin square design. All subjects completed a battery of cognitive and psychomotor pelformance tests (Critical Flicker Fusion Threshold : CFFT, Choice Reaction Time : CRT, Compensatory Tracking Test : CTT, Digit-Symbol Substitution Test DSST) and self-estimate for sedation using visual analog rating scales at pre-dose and 2, 4, 6, 8hr post-dose. The results were as follows : 1) Chlorpromazine 50mg significantly impaired CFFT, CRT, CTT and DSST compared to placebo and showed the most potent sedative effect among the test drugs. These effects occurred in almost all ranges of time points with peak effEct at 4hr post-dose. 2) Haloperidol 2 mg did not impair any cognitive or psychomotor performances. There was no sedative effect as well. 3) Nemo-napride 3 mg selectively impaired CFFT (at 2 and 6hr post-dose), total reaction time (at 4hr post-dose) of CRT and DSST (at 4 and 6hr post-dose). Sedative effect occurred more significantly than placebo at 4 and 6 hr post-dose. These results indicate that nemonapride 3mg seems to have the intermediate profiles between chlorpromazine 50mg and haloperidol 2mg in terms of cognitive and psychomotor effects as well as sedative effect. In addition, inspection of the results suggest that the cognitive and psychomotor effects could be secondary to sedative effect.

Differences of Cognitive Function and Treatment Response between Smoking and Non-smoking Schizophrenic Patients / 신경정신의학

OBJECTIVES: The purpose of this study was to examine the differences of past histories, current symptoms, treatment responses and cognitive functions between smoking and nonsmoking schizophrenic patients. METHODS: The subjects were composed of 67 schizophrenic patients including 36 smokers and 31 non-smokers. They were examined by psychiatric history checklist, Simpson and Angus's rating scale for extrapyramidal side effects, positive and negative syndromes scale(PANSS), global assessment scale(GAS), and Vienna test including Standard Progressive Matrices(SFM), Cognitron, and Flicker Fusion Analyzer(FFA). RESULTS: The results were as follows: 1) Although the duration of illness of smokers was longer than that of non-smokers, the smokers had significantly higher score of GAS and significantly lower score of PANSS than non-smokers at admission 2) With effects of age and duration of illness controlled, there were no differences of mean dosage of neuroleptics, extrapyramldal side effects, PANSS improvement rate and GAS improvement rate between both groups. 3) With effects of age, duration of illness, and total PANSS score controlled, there were no differences of score of SFM, cognitron, and FFA. 4) In smokers, the PANSS improvement rate and the GAS improvement rate were positively correlated with mean number of daily smoked cigarettes, with effects of age and duration of illness controlled. CONCLUSIONS: In schizophrenic patients, smokers had less severe symptoms than non-smokers. In smokers, the PANSS improvement rate and the GAS improvement rate were positively correlated with mean number of daily smoked cigarettes. But smokers were not proven to have received higher dosage of neuroleptics, to have lower extrapyramidal side effects, or to have less severe impairment of cognitive function.

Avaliaçäo da funçäo macular e da funçäo dos cones em pacientes com retinose pigmentar por meio de: potencial visual evocado por padräo reverso, potencial visual evocado focal, flicker perimetria / Valuation of the remaining macular and cone function in retinitis pigmentosa patients. The electrophysiologycal tests of pattern visual evoked potencial, focal visual evoked potencial, flicker perimetry

Objetivo: Avaliar a funçäo da mácula e a funçäo dos cones em pacientes com retinose pigmentar (RP) por meio dos exames de potencial visual evocado (PVE) por padräo reverso (PVE-P) potencial visual evocado focal (PVE-F) e da flicker perimetria (FP). Método: O PVE-P realizado foi do tipo steady-state, com uma frequência de reversäo dos quadrados de 6 Hz. Foram testados cinco padröes diferentes: 160, 80, 40, 20 e 10 minutos de arco. Para a realizaçäo do PVE-F foi utilizada uma iluminaçäo homogênea que compreendia 4,5§ de ângulo visual do paciente. A intensidade de luz era controlada através de filtros de densidade neutra. A intensidade do estímulo sem nenhum filtro era de 14.290 mL. A FP era realizada em ambiente fotópico, com um estímulo de 2§, cuja frequência de piscamento era reduzida até que o paciente percebesse. Estimulava-se o centro (0§), e os pontos periféricos (5§, 10§, 20§, 30§, 40§, 50§ e 60§, no meridiano horizontal, tanto no sentido nasal como no temporal). Conclusöes: Em pacientes com RP e AV relativamente preservada, a funçäo da mácula e dos cones pôde ser mensurada pelos exames de PVE-P, PVE-F e FP. Houve uma boa correlaçäo positiva entre a AV e os testes de PVE-P, PVE-F e FP. Houve uma boa correlaçäo positiva entre o CV e o PVE-P. A correlaçäo entre o CV e o resultado do PVE-F e da FP foi fraca. A CAFP do PVE-P teve uma conformaçäo achatada. O gráfico da FP teve uma configuraçäo em montanha. Os cones da retina de pacientes com RP e AV relativamente preservada estavam acometidos em toda a extensäo testada, incluindo a mácula, porém o acometimento foi mais marcante nos cones da periferia do que nos cones da retina central. A funçäo visual remanescente na retina de pacientes com RP e AV relativamente preservada pode ser quantificada pelos exames de PVE-P, PVE-F e FP, permitindo que estes exames sejam incorporados à rotina de avaliaçäo e acompanhamento da progressäo da retinose pigmentar...

Psychostimulant effects of fencamfamine in healthy volunteers

The effects of fencamfamine (25 and 50 mg po) were studied on acute psychophysiological and psychomotor performance in six healthy male volunteers. Stimulant effects, such as greater increases of critical flicker-fusion thereshold, heart rate, blood pressure and stimulation assessed by self-rating, were more pronounced with the higher dose of fencamfamine. Paradoxical sedative effects were obrained with the 25 mg dose. Fencamfamine should not be considered only as an energizing agent, but also as an agent having a psychostimulant profile of effects

Study of Eye Fatigue on Vertical and Horizontal Writings of Newspapers

Authors performed a comparison study of eye fatigue after full 60 minutes continuous reading the prepared daily newspapers which were differently arranged in various writings vertical style or horizontal style, under the illuminations (50, 200 and 1000 Lux)and two kinds of light source(fluorescent lamp and glow lamp), by the flicker fusion test. Healthy persons(8 for young ages: 20~29 yr. old, and 8 for old, ages: 50~59 yr. old) were carefully selected for the purpose of this study. Results are as follows: 1. There is no significant difference in flicker values between vertical and horizontal writings. 2. Flicker values after one hour continuous reading under the illuminlition of 50 and 1000 Lux were significantly decreased in comparison to 200 Lux illumination in old age. (P.<0.05). 3. Flicker values were significantly decreased after 50 minutes continuous reading the newspapers in all conditions, such as style of writing, light sources and illuminations.(p<0.05). 4. Different light sources such as fluorescent lamp and glow lamp also showed no significant differences in inducing eye fatigue. 5. There is no significant difference in inducing eye fatigue between young(20~29 yr. old) and old(50~59 yr. old) age group.