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Journal of Optometry Jun 2024This study aims to compare eye movements monitored with an eye tracker during two visuo-verbal tests for assessing ocular motility. The study explores the potential of...
PURPOSE
This study aims to compare eye movements monitored with an eye tracker during two visuo-verbal tests for assessing ocular motility. The study explores the potential of digital assessment and eye tracking technology in enhancing the understanding of ocular motility during these tests.
METHODS
47 healthy participants were included (20 males, 27 females), with a mean age of 21.34±1.77 years. The participants underwent optometric examinations to ensure visual health and exclude any dysfunctions or pathologies. The experimental protocol involved the digitized versions of the DEM and King-Devick tests, monitored with an eye tracker.
RESULTS
The vertical subtests of DEM test showed fewer saccades, longer fixation durations, smaller saccade amplitudes, and slower saccade speeds compared to the horizontal subtest. The King-Devick test exhibited comparable fixation and saccade numbers, while fixation duration slightly increased with test difficulty. Statistically significant differences were found between the tests, but a positive correlation was observed.
CONCLUSIONS
Statistically significant differences were observed between the DEM and King-Devick tests, indicating that they measure similar aspects but are not interchangeable. The DEM test offers more comprehensive information with vertical saccade assessment. Test duration correlates positively with saccade and fixation count, fixation duration, and saccade speed.
PubMed: 38908038
DOI: 10.1016/j.optom.2024.100517 -
Medical Engineering & Physics Jul 2024Objective Vestibular/ocular deficits occur with mild traumatic brain injury (mTBI). The vestibular/ocular motor screening (VOMS) tool is used to assess individuals...
Objective Vestibular/ocular deficits occur with mild traumatic brain injury (mTBI). The vestibular/ocular motor screening (VOMS) tool is used to assess individuals post-mTBI, which primarily relies upon subjective self-reported symptoms. Instrumenting the VOMS (iVOMS) with technology may allow for more objective assessment post-mTBI, which reflects actual task performance. This study aimed to validate the iVOMS analytically and clinically in mTBI and controls. Methods Seventy-nine people with sub-acute mTBI (<12 weeks post-injury) and forty-four healthy control participants performed the VOMS whilst wearing a mobile eye-tracking on a one-off visit. People with mTBI were included if they were within 12 weeks of a physician diagnosis. Participants were excluded if they had any musculoskeletal, neurological or sensory deficits which could explain dysfunction. A series of custom-made eye tracking algorithms were used to assess recorded eye-movements. Results The iVOMS was analytically valid compared to the reference (ICC 0.85-0.99) in mTBI and controls. The iVOMS outcomes were clinically valid as there were significant differences between groups for convergence, vertical saccades, smooth pursuit, vestibular ocular reflex and visual motion sensitivity outcomes. However, there was no significant relationship between iVOMS outcomes and self-reported symptoms. Conclusion The iVOMS is analytically and clinically valid in mTBI and controls, but further work is required to examine the sensitivity of iVOMS outcomes across the mTBI spectrum. Findings also highlighted that symptom and physiological issue resolution post-mTBI may not coincide and relationships need further examination.
Topics: Humans; Male; Female; Adult; Case-Control Studies; Eye Movements; Brain Concussion; Middle Aged; Vestibule, Labyrinth; Young Adult; Eye-Tracking Technology
PubMed: 38906567
DOI: 10.1016/j.medengphy.2024.104180 -
Epilepsy & Behavior : E&B Jun 2024To explore multiple features of attention impairments in patients with temporal lobe epilepsy (TLE).
AIM
To explore multiple features of attention impairments in patients with temporal lobe epilepsy (TLE).
METHODS
A total of 93 patients diagnosed with TLE at Xiangya Hospital during May 2022 and December 2022 and 85 healthy controls were included in this study. Participants were asked to complete neuropsychological scales and attention network test (ANT) with recording of eye-tracking and electroencephalogram.
RESULTS
All means of evaluation showed impaired attention functions in TLE patients. ANT results showed impaired orienting (p < 0.001) and executive control (p = 0.041) networks. Longer mean first saccade time (p = 0.046) and more total saccadic counts (p = 0.035) were found in eye-tracking results, indicating abnormal alerting and orienting networks. Both alerting, orienting and executive control networks were abnormal, manifesting as decreased amplitudes (N1 & P3, p < 0.001) and extended latency (P3, p = 0.002). The energy of theta, alpha and beta were all sensitive to the changes of alerting and executive control network with time, but only beta power was sensitive to the changes of orienting network.
CONCLUSION
Our findings are helpful for early identification of patients with TLE combined with attention impairments, which have strong clinical guiding significance for long-term monitoring and intervention.
PubMed: 38905916
DOI: 10.1016/j.yebeh.2024.109887 -
PloS One 2024Eye-tracking techniques have gained widespread application in various fields including research on the visual system, neurosciences, psychology, and human-computer...
Eye-tracking techniques have gained widespread application in various fields including research on the visual system, neurosciences, psychology, and human-computer interaction, with emerging clinical implications. In this preliminary phase of our study, we introduce a pilot test of innovative virtual reality technology designed for tracking head and eye movements among healthy individuals. This tool was developed to assess the presence of mild traumatic brain injury (mTBI), given the frequent association of oculomotor function deficits with such injuries. Alongside eye-tracking, we also integrated fMRI due to the complementary nature of these techniques, offering insights into both neural activation patterns and behavioural responses, thereby providing a comprehensive understanding of oculomotor function. We used fMRI with tasks evaluating oculomotor functions: Smooth Pursuit (SP), Saccades, Anti-Saccades, and Optokinetic Nystagmus (OKN). Prior to the scanning, the testing with a system of VR goggles with integrated eye and head tracking was used where subjects performed the same tasks as those used in fMRI. 31 healthy adult controls (HCs) were tested with the purpose of identifying brain regions associated with these tasks and collecting preliminary norms for later comparison with concussed subjects. HCs' fMRI results showed following peak activation regions: SP-cuneus, superior parietal lobule, paracentral lobule, inferior parietal lobule (IPL), cerebellartonsil (CT); Saccades-middle frontal gyrus (MFG), postcentral gyrus, medial frontal gyrus; Anti-saccades-precuneus, IPL, MFG; OKN-middle temporal gyrus, ACC, postcentral gyrus, MFG, CT. These results demonstrated brain regions associated with the performance on oculomotor tasks in healthy controls and most of the highlighted areas are corresponding with those affected in concussion. This suggests that the involvement of brain areas susceptible to mTBI in implementing oculomotor evaluation, taken together with commonly reported oculomotor difficulties post-concussion, may lead to finding objective biomarkers using eye-tracking tasks.
Topics: Humans; Magnetic Resonance Imaging; Pilot Projects; Adult; Male; Female; Eye-Tracking Technology; Eye Movements; Saccades; Young Adult; Pursuit, Smooth; Brain; Middle Aged; Nystagmus, Optokinetic
PubMed: 38905269
DOI: 10.1371/journal.pone.0303596 -
Frontiers in Artificial Intelligence 2024The scanpath is an important concept in eye tracking. It refers to a person's eye movements over a period of time, commonly represented as a series of alternating... (Review)
Review
The scanpath is an important concept in eye tracking. It refers to a person's eye movements over a period of time, commonly represented as a series of alternating fixations and saccades. Machine learning has been increasingly used for the automatic interpretation of scanpaths over the past few years, particularly in research on passive gaze-based interaction, i.e., interfaces that implicitly observe and interpret human eye movements, with the goal of improving the interaction. This literature review investigates research on machine learning applications in scanpath analysis for passive gaze-based interaction between 2012 and 2022, starting from 2,425 publications and focussing on 77 publications. We provide insights on research domains and common learning tasks in passive gaze-based interaction and present common machine learning practices from data collection and preparation to model selection and evaluation. We discuss commonly followed practices and identify gaps and challenges, especially concerning emerging machine learning topics, to guide future research in the field.
PubMed: 38903158
DOI: 10.3389/frai.2024.1391745 -
Journal of Experimental Psychology.... Jun 2024Negative templates are based on foreknowledge of distractor features and can lead to more efficient visual search at the group level. However, large individual...
Why are some individuals better at using negative attentional templates to suppress distractors? Exploration of interindividual differences in cognitive control efficiency.
Negative templates are based on foreknowledge of distractor features and can lead to more efficient visual search at the group level. However, large individual differences exist in the size of benefits induced by negative cues. The cognitive factors underlying these interindividual differences remain unknown. Previous research has suggested higher engagement of proactive control for negative templates compared to positive templates. We thus hypothesized that interindividual differences in proactive control efficiency may explain the large variability in negative cue benefits. A large data set made up of data from two previously published studies was reanalyzed ( = 139), with eye movements recorded in 36 participants. Individual proactive control efficiency was measured through reaction time (RT) variability. Participants with higher proactive control efficiency exhibited larger benefits after negative cues across two critical measures: Individuals with higher proactive control showed larger RT benefits following negative compared to neutral cues; similarly, individuals with higher proactive control exhibited lower first saccades to cued distractor items. No such relationship was observed for positive cues. Our results confirmed the existence of large interindividual differences in the benefits induced by negative attentional templates. Critically, we show that proactive control drives these interindividual differences in negative template use. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
PubMed: 38900526
DOI: 10.1037/xhp0001214 -
Clinical Medicine Insights. Case Reports 2024Cerebral infarct associated with varicella-zoster virus (VZV) has been reported in the literature, while isolated central dizziness due to lateral medullary infarct...
BACKGROUND
Cerebral infarct associated with varicella-zoster virus (VZV) has been reported in the literature, while isolated central dizziness due to lateral medullary infarct (LMI) following VZV infection is rarely reported.
CASE REPORT
We report the case of a 65-year-old man who presented to the neurology department because of herpes zoster on the right trigeminal nerve distribution. At 12 hours after admission, he developed transient vertigo along with nausea and unsteady walking and left-sided spontaneous horizontal nystagmus, gaze-evoked nystagmus, and upbeat nystagmus. The other usual signs of LMI including Horner syndrome, dysarthria, swallowing difficulty, and hemibody sensory change were absent. Video head impulse indicated decreased head impulse gain of the vestibulo-ocular reflex for the bilateral horizontal, anterior, and posterior semicircular canals with abnormal saccade waves. Suppression head impulse paradigm showed few downward saccades reflecting anti-compensatory saccades after the end of the head impulse back to the head-fixed target and decreased vestibulo-ocular reflex gain values of bilateral semicircular canals. Brain magnetic resonance imaging (MRI) showed a small infarct in the far dorsolateral portion of the left rostral medulla. The cerebrospinal fluid was positive for VZV DNA.
CONCLUSIONS
In patients with VZV infection who develop dizziness, the possibility of cerebral infarct should be considered. Patients with facial herpes zoster and neurological symptoms always be screened for stroke using MRI and lumbar puncture should be performed and acyclovir administered empirically.
PubMed: 38895742
DOI: 10.1177/11795476241262213 -
Cureus May 2024Opsoclonus myoclonus syndrome (OMS) is a rare neurological disorder characterized by irregular, continuous, and chaotic eye saccades accompanied by myoclonus, defined by...
Opsoclonus myoclonus syndrome (OMS) is a rare neurological disorder characterized by irregular, continuous, and chaotic eye saccades accompanied by myoclonus, defined by brief, shock-like muscle spasms in the arms or legs. This syndrome often presents with additional features such as cerebellar syndrome, nycthemeral rhythm disorders, hallucinosis, and irritability-type behavioral disorders. In adults, OMS is predominantly paraneoplastic, necessitating screening for onconeural antibodies (ONA). While specific medications for OMS are lacking, addressing the underlying cause may ameliorate its clinical manifestations. The presence of opsoclonus-myoclonus should prompt urgent and thorough investigation for an underlying cancer, given its frequent association with paraneoplastic neurological syndrome (PNS). Here, we present the case of a 39-year-old patient with opsoclonus associated with cerebellar ataxia, revealing a breast neoplasm with positive anti-YO antibodies. Through the review of the literature, we discuss the epidemiological, clinical, diagnostic, and therapeutic aspects of this rare situation.
PubMed: 38883074
DOI: 10.7759/cureus.60452 -
Otolaryngology--head and Neck Surgery :... Jun 2024To identify the prevalence of and relevant information for video head impulse test (vHIT) abnormality in a large population.
OBJECTIVE
To identify the prevalence of and relevant information for video head impulse test (vHIT) abnormality in a large population.
STUDY DESIGN
A cross-sectional design.
SETTING
Korean National Health and Nutrition Examination Survey, 2021.
METHODS
The sample was representative of the Korean population, with 2237 participants aged ≥40 years. A vHIT was performed to evaluate vestibular function. The vestibulo-ocular reflex (VOR) gain and the presence of reproducible catch-up saccades was assessed in a vHIT. Participants also completed questionnaires for demographics, socioeconomic status, and basic information regarding systemic diseases and dizziness and underwent hearing tests with automated pure-tone audiometry.
RESULTS
The prevalence of vHIT abnormality was 22.5%, with unilateral (14.3%) being more common than bilateral (8.2%). The prevalence of vHIT abnormality increased significantly with age, with the highest rate observed in individuals aged >70 years (42.5%). Both hearing and VOR gain deteriorated with age, but the patterns of age-related progression were different. While hearing loss (HL) deteriorated gradually and progressively throughout adulthood, VOR gain deterioration was markedly evident after 70 years of age.
CONCLUSION
Considering the high prevalence of vHIT abnormality, appropriate social and medical policies are needed to prevent associated injuries and improve patients' quality of life. The distinct age-related changes in HL and objective findings of vestibular dysfunction indicate the need for different approaches to address these social problems in aging countries.
PubMed: 38881387
DOI: 10.1002/ohn.856 -
The Journal of Neuroscience : the... Jun 2024It has been suggested that, prior to a saccade, visual neurons predictively respond to stimuli that will fall in their receptive fields after completion of the saccade....
It has been suggested that, prior to a saccade, visual neurons predictively respond to stimuli that will fall in their receptive fields after completion of the saccade. This saccadic remapping process is thought to compensate for the shift of the visual world across the retina caused by eye movements. To map the timing of this predictive process in the brain, we recorded neural activity using electroencephalography (EEG) during a saccade task. Human participants (male and female) made saccades between two fixation points while covertly attending to oriented gratings briefly presented at various locations on the screen. Data recorded during trials in which participants maintained fixation were used to train classifiers on stimuli in different positions. Subsequently, data collected during saccade trials were used to test for the presence of remapped stimulus information at the post-saccadic retinotopic location in the peri-saccadic period, providing unique insight into remapped information becomes available. We found that the stimulus could be decoded at the remapped location ∼180 ms post-stimulus onset, but only when the stimulus was presented 100-200 ms before saccade onset. Within this range, we found that the timing of remapping was dictated by stimulus onset rather than saccade onset. We conclude that presenting the stimulus immediately before the saccade allows for optimal integration of the corollary discharge signal with the incoming peripheral visual information, resulting in a remapping of activation to the relevant post-saccadic retinotopic neurons. Each eye movement leads to a shift of the visual world across the retina, such that the visual input before and after the eye movement do not match. Despite this, we perceive the visual world as stable. A predictive mechanism known as saccadic remapping is thought to contribute to this stability. We use a saccade task with time-resolved EEG decoding to obtain a fine-grained analysis of the temporal dynamics of the saccadic remapping process. Probing different stimulus-saccade latencies and an array of stimulus locations, we identify when remapped information becomes available in the visual cortex. We describe a critical window in which feedforward visual information and the preparatory motor signals interact to allow for predictive remapping of a stimulus.
PubMed: 38871460
DOI: 10.1523/JNEUROSCI.2134-23.2024