Search Results (247)

Purpose: To investigate the efficacy of a novel test for diagnosing colour vision deficiencies using reflexive eye movements measured using an unmodified tablet. Methods: This study followed a cross-sectional design, where thirty-three participants aged between 17 and 65 years were recruited. The participant group comprised 23 controls, 8 deuteranopes, and 2 protanopes. An anomaloscope was employed to determine the colour vision status of these participants. The study methodology involved using an Apple iPad Pro’s built-in eye-tracking capabilities to record eye movements in response to coloured patterns drifting on the screen. Through an automated analysis of these movements, the researchers estimated individuals’ red–green equiluminant point and their equivalent luminance contrast. Results: Estimates of the red–green equiluminant point and the equivalent luminance contrast were used to classify participants’ colour vision status with a sensitivity rate of 90.0% and a specificity rate of 91.30%. Conclusions: The novel colour vision test administered using an unmodified tablet was found to be effective in diagnosing colour vision deficiencies and has the potential to be a practical and cost-effective alternative to traditional methods. Translation Relevance: The test’s objectivity, its straightforward implementation on a standard tablet, and its minimal requirement for patient cooperation, all contribute to the wider accessibility of colour vision diagnosis. This is particularly advantageous for demographics like children who might be challenging to engage, but for whom early detection is of paramount importance. Full article

This study investigated how simulated ophthalmic visual field deficits affect visual attention and economic information processing. Using webcam-based eye tracking, 227 participants with normal vision recruited through Amazon Mechanical Turk were assigned to control, central vision loss, peripheral vision loss, or scattered vision loss simulation conditions. Participants viewed economic stimuli of varying complexity while eye movements, cognitive load, and comprehension were measured. All deficit conditions showed altered oculomotor behaviors. Central vision loss produced the most severe impairments: 43.6% increased fixation durations, 68% longer scanpaths, and comprehension accuracy of 61.2% versus 87.3% for controls. Visual deficits interacted with information complexity, showing accelerated impairment for complex stimuli. Mediation analysis revealed 47% of comprehension deficits were mediated through altered attention patterns. Cognitive load was significantly elevated, with central vision loss participants reporting 84% higher mental demand than controls. These findings demonstrate that visual field deficits fundamentally alter economic information processing through both direct perceptual limitations and compensatory attention strategies. Results demonstrate the feasibility of webcam-based eye tracking for studying simulated visual deficits and suggest that different types of simulated visual deficits may require distinct information presentation strategies. Full article

Background: Rapid-eye-movement (REM) sleep disinhibition—shorter REM latency and a larger nightly REM fraction—is a well-described laboratory correlate of major depression. Whether the same pattern can be captured efficiently with consumer wearables in everyday settings remains unclear. We therefore quantified REM latency and proportion of REM sleep out of total sleep duration (labeled “REM sleep coefficient”) from Apple Watch recordings and examined their association with depressive symptoms. Methods: 191 adults wore an Apple Watch for 15 consecutive nights while a custom iOS app streamed raw accelerometry and heart-rate data. Sleep stages were scored with a neural-network model previously validated against polysomnography. REM latency and REM sleep coefficient were averaged per participant. Depressive severity was assessed twice with the Beck Depression Inventory and averaged. Descriptive statistics, normality tests, Spearman correlations, and ordinary-least-squares regressions were performed. Results: Mean ± SD values were BDI 13.52 ± 6.79, REM sleep coefficient 24.05 ± 6.52, and REM latency 103.63 ± 15.44 min. REM latency correlated negatively with BDI (Spearman ρ = −0.673, p < 0.001), whereas REM sleep coefficient correlated positively (ρ = 0.678, p < 0.001). Combined in a bivariate model, the two REM metrics explained 62% of variance in depressive severity. Conclusions: Wearable-derived REM latency and REM proportion jointly capture a large share of depressive-symptom variability, indicating their potential utility as accessible digital biomarkers. Larger longitudinal and interventional studies are needed to determine whether modifying REM architecture can alter the course of depression. Full article

Spatial representation is a core element of spatial cognition in orienteering, but the visual-spatial neural modulation mechanisms underlying spatial representations with differently oriented maps have not yet been systematically elucidated. This study recruited 67 orienteering athletes as participants and employed a single-factor (map orientation: normal vs. rotated) between-subjects experimental design. Eye-tracking and functional near-infrared spectroscopy (fNIRS) techniques were used simultaneously to collect behavioral, eye movement, and brain activity data, investigating the effects of map orientation on visual attention and brain activity characteristics during terrain symbol representation processing in orienteering athletes. The results revealed that compared to the normal orientation, the rotated orientation led to significantly decreased task accuracy, significantly prolonged reaction times, and significantly increased saccade amplitude and pupil diameter. Brain activation analysis showed that the rotated orientation elicited significantly higher activation levels in the right dorsolateral prefrontal cortex (R-DLPFC), bilateral parietal lobe cortex (L-PL, R-PL), right temporal lobe (R-TL), and visual cortex (VC) compared to the normal orientation, along with enhanced functional connectivity. Correlation analysis revealed that under normal map orientation, accuracy was positively correlated with both saccade amplitude and pupil diameter; accuracy was positively correlated with activation in the R-DLPFC; saccade amplitude was positively correlated with activation in the R-DLPFC and R-PL; and pupil diameter was positively correlated with activation in the R-DLPFC. Under rotated map orientation, accuracy was positively correlated with saccade amplitude and pupil diameter, and pupil diameter was positively correlated with activation in both the L-PL and R-PL. The results indicate that map orientation significantly influences the visual search patterns and neural activity characteristics of orienteering athletes, impacting task performance through the coupling mode of visual-neural activity. Full article

Fixational saccadic eye movements (microsaccades) have been associated with cognitive processes, especially in tasks requiring spatial attention and memory. Alterations in oculomotor and cognitive control are commonly observed in Parkinson’s disease (PD), though it is unclear to what extent microsaccade activity is affected. We acquired eye movement data from sixteen participants with early-stage PD and thirteen older healthy controls to examine the effects of dopamine modulation on microsaccade activity during the delay period of a spatial working memory task. Some microsaccade characteristics, like amplitude and duration, were moderately larger in the PD participants when they were “on” their dopaminergic medication than healthy controls, or when they were “off” medication, while PD participants exhibited microsaccades with a linear amplitude–velocity relationship comparable to controls. Both groups showed similar microsaccade rate patterns across task events, with most participants showing a horizontal bias in microsaccade direction during the delay period regardless of the remembered target location. Overall, our data suggest minimal involvement of microsaccades during visuospatial working memory maintenance under conditions without explicit attentional cues in both subject groups. However, moderate effects of PD-related dopamine deficiency were observed for microsaccade size during working memory maintenance. Full article

Modern ophthalmic imaging methods such as optical coherence tomography (OCT) typically require expensive scanner components to direct the light beam across the retina while the patient’s gaze remains fixed. This proof-of-concept experiment investigates whether the patient’s natural eye movements can replace mechanical scanning by guiding the gaze along predefined patterns. An infrared fundus camera setup was used with nine healthy adults (aged 20–57) who completed tasks comparing passive viewing of moving patterns to actively tracing them by drawing using a touchpad interface. The active task involved participant-controlled target movement with real-time color feedback for accurate pattern tracing. Results showed that active tracing significantly increased pupil diameter by an average of 17.8% (range 8.9–43.6%; p < 0.001) and reduced blink frequency compared to passive viewing. More complex patterns led to greater pupil dilation, confirming the link between cognitive load and physiological response. These findings demonstrate that patient driven gaze guidance can stabilize gaze, reduce blinking, and naturally dilate the pupil. These conditions might enhance the quality of scannerless OCT or other imaging techniques benefiting from guided gaze and larger pupils. There could be benefits for children and people with compliance issues, although further research is needed to consider cognitive load. Full article

This study investigates visual fatigue in a real-world pharmaceutical packaging environment, where operators perform repetitive inspection and packing tasks under frequently suboptimal lighting conditions. A human-centered methodology was adopted, combining adapted self-report questionnaires, high-frequency eye-tracking data collected with Tobii Pro Glasses 3, and lux-level measurements. Key eye-movement metrics—including fixation duration, visit patterns, and pupil diameter—were analyzed within defined work zones (Areas of Interest). To reduce data complexity and uncover latent patterns of visual behavior, Principal Component Analysis was applied. Results revealed a progressive increase in visual fatigue across the workweek and throughout shifts, particularly during night work, and showed a strong association with inadequate lighting. Tasks involving high physical workload under poor illumination emerged as critical risk scenarios. This integrated approach not only confirmed the presence of visual fatigue but also identified high-risk conditions in the workflow, enabling targeted ergonomic interventions. The findings provide a practical framework for improving operator well-being and inspection performance through sensor-based monitoring and environment-specific design enhancements, in alignment with the goals of Industry 5.0. Full article

Various accelerometers offer to monitor sleep efficiency in dogs, but the underlying proprietary algorithms are not usually revealed. The aim of this pilot study was to achieve insights on the performance of an omnidirectional accelerometer to document sleeping and resting periods in dogs with a simple binary cut-off (0 cpm; ≥1 cpm) and the interference of movements. All data were acquired with a neck collar-mounted accelerometer (Actical^®; Philips Respironics Inc., Murrysville, PA, USA) that provides access to raw data. Ten privately owned dogs (6 dogs with and 4 dogs without movements during sleep) were monitored shortly before, during and after their sleeping and resting periods. Experienced observers documented any visible movement and the corresponding behavioral state continuously for each minute as apparent sleep (eyes closed, regular breathing pattern), rest (eyes open), awake and alert. Total observation time was 2633 min, and 32 sleeping and resting periods were monitored. Zero accelerometer counts per minute documented the combined sleeping and resting periods with a sensitivity of 94.0% and specificity of 96.1% but could not differentiate between apparent sleeping and resting with eyes closed or open. Mild movements during sleep did not interfere with the recordings. The pilot data obtained in this study supports further investigation of this approach to document sleeping and resting periods over prolonged periods in individual dogs. Full article

Eye tracking and EMG are novel measurement technologies that can be used to assess perceptual processes in sports under real-life conditions. The study was conducted on two groups of soccer goalkeepers (N = 60): Group A—expert goalkeepers (22.8 ± 2.15 years of age; training experience 12.77 ± 3.89 years); Group B—novice goalkeepers (15.70 ± 1.12 years of age; training experience 8.35 ± 2.68 years). Main findings: 1. The elite goalkeepers (Group A) focused most of their attention on only one main object (the foot of the opponent’s kicking leg) compared to novice youth goalkeepers (Group B), whose area of interest consisted of more elements: the knee, the lower leg, the foot of the attacking leg, and the ball. 2. The elite goalkeepers (Group A) showed a significantly shorter decision-making time (240–260 ms) than the novice goalkeepers (290–310 ms) in a two-on-one match situation. 3. The use of anticipatory perceptual skills resulted in more accurate anticipation and decision making in elite goalkeepers than in novice goalkeepers, whose perceptual patterns were more dispersed. 4. The anticipatory activity and structure of bioelectric tensions of the rectus femoris (RF) muscle provide useful information for the development of successful anticipatory actions. The ability to recognize signals is a prerequisite for combining movement sequences according to a predetermined pattern and allows for accurate decision making in the goalkeeper’s playing strategy. Full article

Exhibition design in museum environments serves as a vital mechanism for enhancing cultural engagement, enriching visitor experience, and promoting heritage preservation. Despite the growing number of museums, improvements in exhibition quality remain limited. In this context, understanding exhibition visual content becomes fundamental to shaping visitor experiences in cultural heritage settings, as it directly influences how individuals perceive, interpret, and engage with displayed information. However, due to individual differences in cognitive processing, standardized visualization strategies may not effectively support all users, potentially resulting in unequal levels of knowledge acquisition and engagement. This study presents a quasi-experimental eye-tracking investigation examining how visualizer–verbalizer (V–V) cognitive styles influence content comprehension in a historical museum context. Participants were classified as visualizers or verbalizers via standardized questionnaires and explored six artifacts displayed through varying information modalities while their eye movements—including fixation durations and transition patterns—were recorded to assess visual processing behavior. The results revealed that participants’ comprehension performance was strongly associated with their visual attention patterns, which differed systematically between visualizers and verbalizers. These differences reflect distinct visual exploration strategies, with cognitive style influencing how individuals allocate attention and process multimodal exhibition content. Eye movement data indicated that visualizers engaged in broader cross-modal integration, whereas verbalizers exhibited more linear, text-oriented strategies. The findings provide empirical evidence for the role of cognitive style in shaping visual behavior and interpretive outcomes in museum environments, underscoring the need for cognitively adaptive exhibition design. Full article

Sleep is a vital biological function governed by neuronal networks in the brainstem, hypothalamus, and thalamus. Disruptions in these circuits contribute to the sleep disturbances observed in neurodegenerative disorders, including Parkinson’s disease, epilepsy, Huntington’s disease, and Alzheimer’s disease. Oxidative stress, mitochondrial dysfunction, neuroinflammation, and abnormal protein accumulation adversely affect sleep architecture in these conditions. The interaction among these pathological processes is believed to modify sleep-regulating circuits, consequently worsening clinical symptoms. This review examines the cellular and molecular mechanisms that impair sleep regulation in experimental models of these four disorders, emphasizing how oxidative stress, neuroinflammation and synaptic dysfunction contribute to sleep fragmentation and alterations in rapid eye movement (REM) sleep and slow-wave sleep (SWS) phases. In Parkinson’s disease models (6-OHDA and MPTP), dopaminergic degeneration and damage to sleep-regulating nuclei result in daytime somnolence and disrupted sleep patterns. Epilepsy models (kainate, pentylenetetrazole, and kindling) provoke hyperexcitability and oxidative damage, compromising both REM and SWS. Huntington’s disease models (R6/2 and 3-NP) demonstrate reduced sleep duration, circadian irregularities, and oxidative damage in the hypothalamus and suprachiasmatic nucleus. In Alzheimer’s disease (AD) models (APP/PS1, 3xTg-AD, and Tg2576), early sleep problems include diminished SWS and REM sleep, increased awakenings, and circadian rhythm disruption. These changes correlate with β-amyloid and tau deposition, glial activation, chronic inflammation, and mitochondrial damage in the hypothalamus, hippocampus, and prefrontal cortex. Sleep disturbances across these neurodegenerative disease models share common underlying mechanisms like oxidative stress, neuroinflammation, and mitochondrial dysfunction. Understanding these pathways may reveal therapeutic targets to improve both motor symptoms and sleep quality in neurodegenerative disorders. Full article

A 51-year-old female presented to the emergency department with vertigo, visual disturbances, involuntary rapid repetitive eye movements, incoordination, and imbalance. Physical examination revealed opsoclonus, myoclonus, and bilateral limb and gait ataxia. Initial workup was negative for intracranial abnormalities, and no abnormalities were noted on blood work or cerebrospinal fluid analysis. Tumor markers were within normal limits. As part of her diagnostic workup, a positron emission tomography (PET) scan was performed, which showed a highly FDG-avid solitary 7 mm left axillary lymph node. Ultrasound-guided percutaneous biopsy revealed metastatic poorly differentiated carcinoma. Histopathological examination could not conclusively distinguish between adenocarcinoma and squamous cell carcinoma. She was diagnosed with seronegative opsoclonus-myoclonus ataxia syndrome of paraneoplastic origin from an occult primary malignancy and started on pulsatile corticosteroids and intravenous immunoglobulin (IVIG), with only moderate symptomatic improvement. Given the anatomic location and immunohistochemical staining pattern of the lymph node, the malignancy was considered as being of primary breast origin. A left axillary lymph node dissection was performed, with 1/12 nodes testing positive for poorly differentiated carcinoma. The patient experienced significant improvement in her neurological symptoms 2–3 days following resection of the solitary malignant lymph node, largely regaining her functional independence. She went on to receive adjuvant radiotherapy to the breast and axilla, as well as adjuvant hormonal therapy. Full article

Background/Objectives: Rapid eye movements (REMs) during sleep were initially associated with dreaming, suggesting a relationship between REMs and dream content; however, this hypothesis was questioned by their differences with the REMs during wakefulness and the evidence that REMs are also present in blind individuals with no visual dreaming. Successive studies have focused on the phenomenology and physiological significance of REMs during sleep. REMs are categorized as expressions of the phasic REM component, which is characterized by bursts of eye movements, whereas the tonic REM component is characterized by quiescent periods without eye movements. Methods: The study is a retrospective analysis of 105 sleep records from 15 subjects. We analyzed the two components, tonic and phasic REM, across the sleep period, the REM activity in the first 5 min and in the last 5 min of each REM period were also assessed. Results: Phasic epochs were more represented than tonic epochs across the whole night period. REM activity in the first and last five minutes of an REM period presented different, although non-significant, patterns across the night. REM activity in the first 5 min showed a curvilinear profile, whereas REM activity in the last 5 min showed a linear increasing trend. A significant correlation was found between the REM activity in the first 5 min of the REM period and the total duration of the REM period. Conclusions: According to our results, the analysis of REM activity and the focus on segments of an REM period could provide more information both on the temporal evolution of REM activity within an REM period and on the possible role of REMs in REM sleep regulation and its significance in psychiatric and neurological disorders. Full article

This paper presents a novel EEG-based learning system designed to enhance the efficiency and effectiveness of studying by dynamically adjusting the difficulty level of learning materials based on real-time attention levels. In the training phase, EEG signals corresponding to high and low concentration levels are recorded while participants engage in quizzes to learn and memorize Chinese characters. The attention levels are determined based on performance metrics derived from the quiz results. Following extensive preprocessing, the EEG data undergoes several feature extraction steps: removal of artifacts due to eye blinks and facial movements, segregation of waves based on their frequencies, similarity indexing with respect to delay, binary thresholding, and (PCA). These extracted features are then fed into a k-NN classifier, which accurately distinguishes between high and low attention brain wave patterns, with the labels derived from the quiz performance indicating high or low attention. During the implementation phase, the system continuously monitors the user’s EEG signals while studying. When low attention levels are detected, the system increases the repetition frequency and reduces the difficulty of the flashcards to refocus the user’s attention. Conversely, when high concentration levels are identified, the system escalates the difficulty level of the flashcards to maximize the learning challenge. This adaptive approach ensures a more effective learning experience by maintaining optimal cognitive engagement, resulting in improved learning rates, reduced stress, and increased overall learning efficiency. Our results indicate that this EEG-based adaptive learning system holds significant potential for personalized education, fostering better retention and understanding of Chinese characters. Full article

Given the severe global traffic safety challenges—including threats to human lives and socioeconomic impacts—this study analyzes visual behavior to promote sustainable transportation, improve road safety, and reduce resource waste and pollution caused by accidents. Four typical road sections, namely, turning, straight ahead, uphill, and downhill, were selected, and the eye movement data of 23 drivers in different driving stages were collected by aSee Glasses eye-tracking device to analyze the visual gaze characteristics of the drivers and their transfer patterns in each road section. Using Markov chain theory, the probability of staying at each gaze point and the transfer probability distribution between gaze points were investigated. The results of the study showed that drivers’ visual behaviors in different road sections showed significant differences: drivers in the turning section had the largest percentage of fixation on the near front, with a fixation duration and frequency of 29.99% and 28.80%, respectively; the straight ahead section, on the other hand, mainly focused on the right side of the road, with 31.57% of fixation duration and 19.45% of frequency of fixation; on the uphill section, drivers’ fixation duration on the left and right roads was more balanced, with 24.36% of fixation duration on the left side of the road and 25.51% on the right side of the road; drivers on the downhill section looked more frequently at the distance ahead, with a total fixation frequency of 23.20%, while paying higher attention to the right side of the road environment, with a fixation duration of 27.09%. In terms of visual fixation, the fixation shift in the turning road section was mainly concentrated between the near and distant parts of the road ahead and frequently turned to the left and right sides; the straight road section mainly showed a shift between the distant parts of the road ahead and the dashboard; the uphill road section was concentrated on the shift between the near parts of the road ahead and the two sides of the road, while the downhill road section mainly occurred between the distant parts of the road ahead and the rearview mirror. Although drivers’ fixations on the front of the road were most concentrated under the four road sections, with an overall fixation stability probability exceeding 67%, there were significant differences in fixation smoothness between different road sections. Through this study, this paper not only reveals the laws of drivers’ visual behavior under different driving environments but also provides theoretical support for behavior-based traffic safety improvement strategies. Full article