OBJECTIVE: To examine the influence of sleep quality on psychophysiological testing results and autonomic state in university students of both sexes with different habitual physical activity level.
METHODS: One hundred and twenty-four 6th year medical students (88 women and 36 men) and 80 sport science students (42 women and 38 men) underwent a comprehensive psychophysiological study, including 7 tests: simple motor reaction, choice reaction, reaction under conditions of interference, reaction to a moving object, critical fusion frequency, as well as static and dynamic (by profile) dexterity tests. Autonomic status was assessed using heart rate variability, sleep quality and alertness were assessed based on self-report, and in athletes, using the Pittsburgh Sleep Quality Questionnaire (PSQI).
RESULTS: In the male athletes\' group with morning chronotype the sleep quality was better than in medical students. Only female medical students demonstrated a deterioration in praxis with an increase in the severity of evening features in the chronotype and a decrease in self-assessment of sleep quality. Increased sleepiness in the first half hour after awakening significantly reduced the quality of performance of psychometric tests in all subjects. The most informative was critical fusion frequency, which was lower in girls with «poor» sleep, as well as the reaction to a moving object. In addition, sympathetic drive was increased in female medical students with poor self-rated sleep quality.
CONCLUSIONS: A decrease in the quality of sleep in students causes fine motor impairment, mediated by sex, the level of habitual physical activity and circadian chronotype.
UNASSIGNED: Изучить влияние самооценки качества сна на показатели психометрического тестирования и вегетативный статус у студентов разных полов и уровня привычной двигательной активности.
UNASSIGNED: Представлены результаты обследования 124 студентов 6-го курса (88 девушек и 36 юношей), изучающих медицину, и 80 студентов (42 девушки и 38 юношей) специальности «физическая культура». Всем студентам проведено комплексное психофизиологическое исследование, включающее 7 тестов: простую двигательную реакцию, реакцию выбора, реакцию в условиях помехи, реакцию на движущийся объект, критическую частоту слияния мельканий, а также статическую и динамическую (по профилю) координациометрию. Вегетативный статус оценивали по данным вариабельности сердечного ритма, качество сна и активированности — на основании самооценки, а у спортсменов — с использованием Питтсбургского опросника качества сна (PSQI).
UNASSIGNED: Качество сна у юношей-спортсменов, у которых преобладал утренний хронотип, оказалось достоверно лучше, чем у медиков. Только у девушек-медиков обнаружено ухудшение праксиса при увеличении выраженности вечерних черт в хронотипе и снижении самооценки качества сна. Повышенная сонливость в первые полчаса после подъема выраженно снижала качество выполнения психометрических тестов у всех обследованных. Наиболее информативной оказалась критическая частота слияния мельканий, которая была ниже у девушек с «плохим» сном, а также реакция на движущийся объект. Кроме того, только у девушек с «плохим» сном наблюдалось повышение симпатического тонуса вегетативной нервной системы.
UNASSIGNED: Снижение качества сна студентов вызывает нарушения тонкой моторики, опосредованные фактором пола, уровнем привычной двигательной активности и циркадианным хронотипом.

In the era of the Internet of Things and the rapid progress of artificial intelligence, there is a growing demand for advanced dynamic vision systems. Vision systems are no longer confined to static object detection and recognition, as the detection and recognition of moving objects are becoming increasingly important. To meet the requirements for more precise and efficient dynamic vision, the development of adaptive multimodal motion detection devices becomes imperative. Inspired by the varied response rates in biological vision, we introduce the concept of critical flicker fusion frequency (cFFF) and develop an organic optoelectronic synaptic transistor with adjustable cFFF. In situ Kelvin probe force microscopy analysis reveals that light signal recognition in this device originates from charge transfer in the poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b\']dithiophene)-co-(1,3-di(5-thiophene-2-yl)-5,7-bis(2-ethylhexyl)-benzo[1,2-c:4,5-c\']dithiophene-4,8-dione)] (PBDB-T)/pentacene heterojunction, which can be effectively modulated by gate voltage. Building upon this, we implement different cFFF within a single device to facilitate the detection and recognition of objects moving at different speeds. This approach allows for resource allocation during dynamic detection, resulting in a reduction in power consumption. Our research holds great potential for enhancing the capabilities of dynamic visual systems.

OBJECTIVE: Breakfast replenishes glucose homeostasis and provides other micro-nutrients for the normal functioning of the body after a long night at night. Habitually skipping breakfast leads not only to metabolic disturbances but also to neurocognitive impairment. Hence, the current study was carried out to study the effect of skipping breakfast on neurocognitive functions.
METHODS: A 9-item breakfast questionnaire was distributed online to students for identifying habitual breakfast skippers from non-skippers based on inclusion criteria. Random blood glucose was noted and visual and auditory reaction time, critical flicker fusion frequency, and Stroop test were assessed in both groups to assess cognition.
RESULTS: Forty one habitual breakfast skippers who met the inclusion criteria showed increased visual reaction time, and auditory reaction time indicating cognitive impairment. A significant reduction in the Stroop test was observed among the non-skipper group when compared to the skipper group.
CONCLUSIONS: This study suggests that skipping breakfast diminishes neurocognitive functions like problem-solving, planning, judgment, information retention, and reasoning.

UNASSIGNED: Due to media opacity, it is usually difficult to accurately evaluate the postoperative visual acuity in cataracts patients. As a small and portable tool, the critical flicker fusion frequency (CFF) device reflects the temporal resolution of visual function and has been widely used in clinical research. However, poor understanding of the technique and equipment limitations have restricted its clinical application in China.
UNASSIGNED: There was a decrease in the CFF value in various ophthalmic diseases, indicating that the CFF is sensitive to detect visual functional changes. A number of studies have shown that the CFF test can accurately distinguish patients with simple cataracts from those with cataracts combined with fundus disease, and, as a visual test, it can more accurately predict postoperative visual acuity without being affected by media opacity. This study comprehensive reviews the basic principles of CFF and its application in ophthalmology, especially in cataracts.
UNASSIGNED: As one of the tools for dynamic visual function detection, the CFF test could help doctors to assess the possible presence of fundus disease in cataracts patients, especially in eyes with dense cataracts, and more precisely provide a reasonable visual prognosis than other available visual tests.

UNASSIGNED: To investigate the application of critical flicker fusion frequency (CFF) in demyelinating optic neuritis (DON).
UNASSIGNED: A cross-sectional study. A total of 127 eyes in 69 DON patients and 63 eyes in 33 healthy control (HC) groups were included between January 2021 to September 2021 from Department of Ophthalmology, PLA General Hospital. Patients underwent best-corrected visual acuity (BCVA), visual field, optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and CFF examinations. The affected eyes were divided into aquaporins 4 (AQP4-), myelin oligodendrocyte glycoprotein (MOG-), and double negative DON according to serum antibody; mild, moderate, severe degree visual impairment according to BCVA ≥ 0.5, 0.1-0.5, < 0.1; and 4 groups: < 1, 1 ∼< 3, 3 ∼ < 6 and > 6 months according to time interval from onset to CFF examination. One-way ANOVA was used to perform above subgroup analysis. The correlations between CFF and F-VEP peak time, peak value, BCVA and mean visual filed defect (MD) were analyzed in order via Pearson correlation analysis.
UNASSIGNED: he trichromatic values of red, green, and yellow in DON affected eyes were 21.83 ± 9.03, 23.66 ± 10.21, 24.09 ± 10.77 Hz, respectively, which was significantly reduced compared with the HC group (t = -14.82, -14.22, -14.00; P < 0.001). The subgroup analysis showed no significant difference between different antibody subtypes (P = 0.914 <0.848 <0.604), whereas, a significant decrease of CFF trichromatic value was found in severe visual acuity impairment group (P < 0.001). There was a significant difference in CFF- trichromatic values at different time points (P < 0.001), to be specific, CFF fluctuated under 20Hz within 3 months after onset and tended to be stable around 24-28Hz. Correlation analysis showed that the peak time of F-VEP (r = -0.486, -0.515, -0.526; P < 0.001), BVCA (r = -0.640, -0.659, -0.642; P < 0.001), were negatively correlated with CFF trichromatic values, MD and CFF were positively correlated (r = 0.486, 0.453, 0.476; P = 0.003, 0.006, 0.004).
UNASSIGNED: A significant decrease of CFF value was found in DON-affected eyes, and it has a good correlation with BCVA, MD and latency of F-VEP, and can better reflect the impairment of visual function.

The critical flicker fusion frequency (cFFF) refers to the frequency at which a regularly recurring change of light stimuli is perceived as steady. The cFFF threshold is often assessed in clinics to evaluate the temporal characteristics of the visual system, making it a common test for eye diseases. Additionally, it serves as a helpful diagnostic tool for various neurological and internal diseases. In the field of diving/hyperbaric medicine, cFFF has been utilized to determine alertness and cognitive functions. Changes in the cFFF threshold have been linked to the influence of increased respiratory gas partial pressures, although there exist inconsistent results regarding this effect. Moreover, the use of flicker devices has produced mixed outcomes in previous studies. This narrative review aims to explore confounding factors that may affect the accuracy of cFFF threshold measurements, particularly in open-field studies. We identify five broad categories of such factors, including (1) participant characteristics, (2) optical factors, (3) smoking/drug use, (4) environmental aspects, and (5) breathing gases and partial pressures. We also discuss the application of cFFF measurements in the field of diving and hyperbaric medicine. In addition, we provide recommendations for interpreting changes in the cFFF threshold and how they are reported in research studies.

This study aimed to determine work-rest schedules for visual tasks of different lengths by evaluating visual fatigue and visually induced motion sickness (VIMS) using an optical head-mounted display (OHMD). Thirty participants were recruited to perform 15 and 30 min visual tasks using an OHMD. After completing each visual task, participants executed six levels of rest time. Critical flicker fusion frequency (CFF) values, relative electroencephalography indices, and Simulator Sickness Questionnaire (SSQ) scores were collected and analyzed. Results indicated that after completing the 15 and 30 min visual tasks, participants experienced visual fatigue and VIMS. There was no significant difference between baseline CFF values, four electroencephalography relative power index values, and SSQ scores when participants completed a 15 min visual task followed by a 20 min rest and a 30 min visual task followed by a 30 min rest. Based on our results, a 20 min rest for visual fatigue and VIMS recovery after a 15 min visual task on an OHMD and a 25 min rest for visual fatigue and VIMS recovery after a 30 min visual task on an OHMD are recommended. This study suggests a work-rest schedule for OHMDs that can be used as a reference for OHMD user guidelines to reduce visual fatigue and visually induced motion sickness.

The aim of this review is to summarise current knowledge about flickering light and the underlying processes that occur during its processing in the brain. Despite the growing interest in the topic of flickering light, its clinical applications are still not well understood. Studies using EEG indicate an appearing synchronisation of brain wave frequencies with the frequency of flickering light, and hopefully, it could be used in memory therapy, among other applications. Some researchers have focused on using the flicker test as an indicator of arousal, which may be useful in clinical studies if the background for such a relationship is described. Since flicker testing has a risk of inducing epileptic seizures, however, every effort must be made to avoid high-risk combinations, which include, for example, red-blue light flashing at 15 Hz. Future research should focus on the usage of neuroimaging methods to describe the specific neuropsychological and neurophysiological processes occurring in the brain during the processing of flickering light so that its clinical utility can be preliminarily determined and randomised clinical trials can be initiated to test existing reports.

Critical flicker fusion frequency (CFF) is a short but sensitive method for evaluating optic nerve function. We measured CFF in patients with pituitary neuroendocrine tumors (Pit-NETs) to assess its usefulness. Data from 184 patients with nonfunctioning Pit-NETs, who had been treated with transsphenoidal surgery and had no medical history of eye diseases, was used in this retrospective study. Visual acuity decline (VAD) was defined as > 0.10 reduction in logMAR visual acuity and CFF decline (CFD) was defined as CFF value < 35 Hz. Visual field defect (VFD) was evaluated by automated perimetry on a Humphrey visual field analyzer. Potential associations between abnormal test results and tumor height from the suprasellar were analyzed. Contact between the optic nerve or chiasma and the tumor was present and absent in 161 and 23 patients, respectively. In patients showing contact, the difference in CFF between the left and right eyes was larger (p = 0.0008), and the optimal cutoff value using the receiver operating characteristic curve was 3 Hz. Therefore, ≥ 3 Hz was considered positive for CFF laterality (CFL), the most prevalent condition. Tumor height was lower in patients with CFL positivity compared to those with VAD or VFD (p < 0.01). The prevalence of test abnormalities was the highest for small tumors compared to those of other tests. Changes in CFL permit early detection of Pit-NETs. Our results indicate that CFF laterality can be seen in the early stages of compressive optic neuropathy due to Pit-NET.

This review presents the current knowledge of the usage of critical flicker fusion frequency (CFF) in human and animal model studies. CFF has a wide application in different fields, especially as an indicator of cortical arousal and visual processing. In medicine, CFF may be helpful for diagnostic purposes, for example in epilepsy or minimal hepatic encephalopathy. Given the environmental studies and a limited number of other methods, it is applicable in diving and hyperbaric medicine. Current research also shows the relationship between CFF and other electrophysiological methods, such as electroencephalography. The human eye can detect flicker at 50-90 Hz but reports are showing the possibility to distinguish between steady and modulated light up to 500 Hz. Future research with the use of CFF is needed to better understand its utility and application.