Search

Introduction and Purpose Methods Results Conclusions The developmental eye movement (DEM) test is designed to assess saccadic eye movements and visual‐verbal automaticity in children. This study aimed to assess whether there is a need for independent DEM Hebrew norms and to compare DEM results for Hebrew‐speaking children with eight other language norms.The DEM test was administered to 224 Hebrew‐speaking children aged 6–13 years who met the inclusion criteria and read the numbers in Hebrew. Test C of the DEM was performed twice, once from right (R) to left (L) and once from L to R, in random order. Age group and language comparisons, including vertical and horizontal reading speeds, errors and horizontal/vertical (H/V) ratios in both directions were analysed.The participants were almost evenly distributed between the sexes (46.8% female). Statistically significant differences were found between age groups (6–9 and 10–13 years) for vertical and horizontal reading speeds and H/V ratios in both directions (p < 0.001). Older children, as compared to younger children, exhibited faster vertical and horizontal times, with fewer errors, as well as lower ratios (p < 0.001). No significant difference was noted between reading directions for horizontal time and H/V ratio within both age groups (6–9 year olds: p = 0.27 and p = 0.06; 10–13 year olds: p = 0.89 and p = 0.49, respectively). Comparison of DEM norms across languages showed significant differences, with post‐hoc analysis revealing specific language‐related variations. DEM results for Hebrew‐speaking children had similar outcomes to both original English and French values.This study compared DEM results of Hebrew‐speaking children and scores across nine languages. DEM test values for Hebrew‐speaking children aligned with norms from other languages, particularly the French and original English norms, with consistent ratio scores. It is recommended for practitioners who test Hebrew‐speaking children to continue using the original English norms and to enable the children to read using their preferred reading direction. [ABSTRACT FROM AUTHOR]

Saccadic eye movements, a critical aspect of real‐world visual behavior, are preceded by an initial accumulation of visual information followed by the selection of a single location to move one's eyes. However, it is currently unclear how each of these stages uniquely affects saccadic timing. In this study, participants searched for a contour integration target while EEG was used to measure posterior cortical activity between search display onset and first saccade initiation. The goal was to determine whether saccade timing could be attributed to differences in early ERP amplitudes, with the P1 reflecting the magnitude of early perceptual information accumulation and the N1 reflecting the strength of selection leading to the saccadic decision. EOG was used to measure saccade timing, and trials were divided into fast, middle, and slow bins. The N1 response was smallest in the slow saccade tertile, relative to both the fast and middle tertiles, suggesting weak selection. In contrast, the P1 response was largest for this same slow saccadic tertile relative to the middle saccadic tertile, suggesting vigorous information accumulation. Therefore, delays in saccadic behavior may occur when the visual system is overwhelmed with visual input, thus increasing the time to reach a saccadic decision. These findings reconcile models of eye movement behavior which often prioritize either the impact of information accrual or selection, rather than regarding both as an integrated whole. [ABSTRACT FROM AUTHOR]

Saccades are rapid eye movements that are used by all species with good vision. In this study, we set out to characterize the complete repertoire of larval zebrafish horizontal saccades to gain insight into their contributions to visually guided behavior and underlying neural control. We identified five saccade types, defined by systematic differences in kinematics and binocular coordination, which were differentially expressed across a variety of behavioral contexts. Conjugate saccades formed a large group that serves at least four functions. These include fast phases of the optokinetic nystagmus, visual scanning in stationary animals, and shifting gaze in coordination with body turns. In addition, we discovered a previously undescribed pattern of eye-body coordination in which small conjugate saccades partially oppose head rotation to maintain gaze during forward locomotion. Convergent saccades were coordinated with body movements to foveate prey targets during hunting. Detailed kinematic analysis showed that conjugate and convergent saccades differed in the millisecond coordination of the eyes and body and followed distinct velocity main sequence relationships. This challenges the prevailing view that all horizontal saccades are controlled by a common brainstem circuit and instead indicates saccade-type-specific neural control. • Kinematic analysis of thousands of rapid eye movements reveals five saccade types • Conjugate saccades have at least four identifiable visual functions • Convergent saccades are coordinated with body movements to foveate prey • Distinct main sequence relationships imply saccade-type-specific neural control Dowell et al. characterize the repertoire of saccadic eye movements of larval zebrafish and examine their coordination with swims during visuomotor behaviors. Differences in timing, kinematics, and velocity main sequences indicate that different saccade types are controlled by distinct patterns of brainstem activity. [ABSTRACT FROM AUTHOR]

Concussion assessment in adapted and parasport athletes has continued to evolve with growing considerations in parasports, but little is known about vestibular/ocular performance assessment in this sample. To examine baseline performance on the Vestibular/Ocular Motor Screening (VOMS) in collegiate adapted athletes. A secondary objective was to investigate the role of sex, history of concussion, and functional classification on baseline measures. Cross-sectional study. University adapted athletics facility. Fifty-four collegiate adapted athletes (age = 21.19 ± 2.6 years) from multiple institutions' adapted athletics programs across the United States. Adapted athletes completed a baseline VOMS assessment while at the host university for in-season competition and tournaments. Independent variables were sex, history of concussion and functional classification (1.0–4.5 at 0.5 intervals). Vestibular/Ocular Motor Screening performance consisted of pretest symptoms (headache, dizziness, nausea, and fogginess) and postitem (eg, smooth pursuits, saccades) symptom provocation or change from pretest scores. A proportion of 50.9% reported zero symptom provocation on the VOMS, with 72% having no pretest symptoms. No sex differences were noted on the VOMS (P >.05); however, adapted athletes with a history of concussion reported greater VOMS provocation on horizontal saccades (P =.008) than those with no history. Higher functional classifications (2.0–4.5) reported greater provocation on horizontal saccades (P =.010), horizontal and vertical (P =.043 and.048) vestibular/ocular reflex, and vestibular/ocular reflex cancellation (P =.036) than 1.0–1.5 athletes. Our findings provide context for baseline VOMS performance in collegiate adapted athletes and identifying modifiers at baseline. Special consideration is warranted on vestibular and oculomotor assessment in adapted and parasport athletes with a history of concussion and higher functional classifications. [ABSTRACT FROM AUTHOR]

Glaucoma is a progressive optic neuropathic disorder that significantly impacts the activities of daily life (ADLs) of individuals. Emerging studies indicate degenerative changes in cortical and subcortical regions in individuals with glaucoma, which are associated with cognitive processes and oculomotor control. Cognitive processes involving top-down processes such as attention, planning, task management and execution, are crucial for meeting the demands of everyday tasks, and are affected in glaucoma. This study investigated the executive functions, specifically inhibitory control (IC) and working memory (WM), in individuals with glaucoma compared to age-matched controls, using eye movements. This was achieved through four tasks sensitive to executive functions, including antisaccade, memory-guided prosaccade and antisaccade, and the Go-NoGo tasks. Saccadic eye-movement parameters were also assessed in a prosaccade task, considered as a control condition with minimal IC and WM load. The results indicated that glaucoma is associated with changes in both IC and WM. Increased anticipatory saccadic errors might be linked to inhibitory deficiencies during the preparatory stage of the saccadic suppression mechanism. The increased omission errors in the antisaccade task might be due to the lack of regulation of the WM component. Taken together, these findings provide evidence for the involvement of cognitive deficits in individuals with glaucoma. [ABSTRACT FROM AUTHOR]

Background/Objectives: Cervical dystonia (CD) is a condition characterized by involuntary activity of cervical muscles, which is often accompanied by various non-motor symptoms. Recent studies indicate impaired saccadic eye movements in CD. Local administration of botulinum toxin type A (BoNT/A), which causes temporary paralysis of the injected muscle, is the first-line treatment of focal dystonia, including CD. To our knowledge, concurrent observation of the effect of BoNT/A on smooth eye movements, voluntary saccades, memory-guided saccades, and antisaccades in CD has not yet been explored. The aim of this study was to assess the effect of BoNT/A on eye movements and non-motor symptoms in patients with CD, which, when altered, could imply a central effect of BoNT/A. Methods: Thirty patients with CD performed smooth pursuit, prosaccadic expression, memory-guided saccades, and antisaccade tasks; eye movements were recorded by an eye tracker. Motor and non-motor symptoms, including depression, anxiety, pain, disability, and cognitive changes prior to and after BoNT/A administration, were also evaluated. Results: The number of correct onward counts (p < 0.001), overall correct memory-guided saccades count (p = 0.005), motor symptoms (p = 0.001), and non-motor symptoms, i.e., anxiety (p = 0.04), depression (p = 0.02), and cognition (p < 0.001) markedly improved after BoNT/A administration. Conclusions: Memory-guided saccades, depression, and anxiety improve after BoNT/A in CD. [ABSTRACT FROM AUTHOR]

Idiopathic epilepsy (IE), is a group of epileptic syndromes with no structural brain lesion, but with microstructural changes in neuronal networks leading to neuropsychological consequences. Therefore, the assessment of saccadic eye movements can provide insight into the integrity of cerebral networks as it involves large cortical and subcortical brain areas and circuitries. Describe saccadic eye movement abnormalities in patients with IE and correlate them with disease characteristics and antiseizure medication. Case–control study including IE patients followed in the Neurology Department of Razi University Hospital and healthy controls matched. Participants underwent a recording of saccadic eye movements. Pursuit, prosaccade, and anti-saccade tasks were performed. 115 patients and 98 matched healthy controls were included. The gender ratio (male to female) was 0.6. The mean age at onset was 16.3 ± 12 years. Diagnosed epileptic syndromes were juvenile myoclonic epilepsy (JME), epilepsy with generalized tonic-clonic seizures, childhood absence epilepsy, temporal lobe epilepsy, frontal lobe epilepsy, and rolandic epilepsy. Saccadic eye movements were impaired in 52.2% of our patients and significantly more altered in those with JME (p = .021). Prolonged horizontal saccades latencies were the most frequent eye movement abnormalities (32.1%), followed by altered horizontal smooth pursuit (22.6%). A positive correlation was found between age at eye movements recording, age at onset, disease duration, global cognitive impairment, and saccadic eye movements. However, no definite relationship was identified. Saccadic eye movement illustrates extending anatomic alterations in IE including frontal and temporoparietal cortical areas and cortico-subcortical circuits. Eye movement recording is a useful and reproducible tool in the assessment of epileptic patients and provides a better understanding of neuronal mechanisms in epilepsy. [ABSTRACT FROM AUTHOR]

Our interest was to evaluate changes in fixation duration as a function of time-on-task (TOT) during a random saccade task. We employed a large, publicly available dataset. The frequency histogram of fixation durations was multimodal and modelled as a Gaussian mixture. For this specific task, we found five fixation types. The "ideal" response would be a single accurate saccade after each target movement, with a typical saccade latency of 200-250 msec, followed by a long fixation (> 800 msec) until the next target jump. We found fixations like this, but they comprised only 10% of all fixations and were the first fixation after target movement only 23.4% of the time. More frequently (57.4% of the time), the first fixation after target movement was short (117.7 msec mean) and was commonly followed by a corrective saccade. Across the entire 100 sec of the task, median total fixation duration decreased. This decrease was approximated with a power law fit with R2 = 0.94. A detailed examination of the frequency of each of our five fixation types over time on task (TOT) revealed that the three shortest duration fixation types became more and more frequent with TOT whereas the two longest fixations became less and less frequent. In all cases, the changes over TOT followed power law relationships, with R2 values between 0.73 and 0.93. We concluded that, over the 100 second duration of our task, long fixations are common in the first 15 to 22 seconds but become less common after that. Short fixations are relatively uncommon in the first 15 to 22 seconds but become more and more common as the task progressed. Apparently. the ability to produce an ideal response, although somewhat likely in the first 22 seconds, rapidly declines. This might be related to a noted decline in saccade accuracy over time. [ABSTRACT FROM AUTHOR]

A better understanding of the relationship between eye movements required for reading and central visual field loss may facilitate the design of more effective personalized visual rehabilitation programs to improve access to information and quality of life. To determine the impact of central vision loss due to maculopathy on the oculomotor skills required for reading and tasks of varying complexity, eye-tracking technology was used. Case-control study. Participants were 17 cases (61.7 years (SD = 8.8), 12 females and 5 males) and 17 controls, matched for age and sex. Three computer-based tests were administered, analyzing eye fixations, saccadic movements, and visual search, measured with a 60 Hz eye-tracking device. Central vision loss due to maculopathy increases the number of fixations and saccadic movements, indicating more instability in and out of the region of interest. Visual search required more fixations (16.2 ± 10.2 vs. 6.7 ± 1.9), more saccades (11.7 ± 6.4 vs. 3.3 ± 1.9), longer latency (701.3 ± 191.4 ms vs. 315.9 ± 56.0 ms), and longer time to find the target (113.1 ± 76.6 s vs. 18.5 ± 10.1 s). All comparisons between the two groups showed a statistically significant difference (P< 0.05). The results revealed the significant impact of central vision loss due to maculopathy on reading by increasing patterns of eye fixations, saccadic movements, and visual search strategies, as measured by eye-tracking technology. This technology may have high potential to improve the assessment and rehabilitation of people with maculopathy, and this may become key information for designing personalized interventions to improve the quality of life and autonomy of individuals with central vision loss. [ABSTRACT FROM AUTHOR]

To compare the corneal biomechanical parameters measured by Corvis ST in subjects with varying degrees of myopia. And the factors that may affect corneal biomechanical properties were also investigated. Participants in this prospective cross-sectional study were classified into three groups according to spherical equivalent (SE) and axial length (AL): Non-myopia (NM, SE > − 0.50 D and AL < 26 mm), Mild-to-moderate myopia (MM, − 6.00 D < SE ≤ − 0.50 D and AL < 26 mm), high myopia (HM, SE ≤ − 6.00 D or AL ≥ 26 mm). Ten corneal biomechanical parameters were finally included. Linear mixed-effects model accounting for using both eyes in the same participant was carried out to evaluate how the corneal biomechanical parameter was influenced by varying degrees of myopia after adjusting for biomechanically corrected intraocular pressure (bIOP) and central corneal thickness (CCT). Further, multiple linear regression was performed to explore the correlation between corneal biomechanical parameter and SE, AL, bIOP or CCT. A total of 304 eyes from 224 healthy myopic subjects were recorded. There were 95 eyes with NM, 122 eyes with MM, and 87 eyes with HM. After adjusting for bIOP and CCT, eyes with high myopia showed shorter highest concavity time (HC-time, p = 0.025), greater peak distance (PD, p = 0.001), greater deflection amplitude (DA-Max, p = 0.002), smaller whole eye movement (WEM-Max, p < 0.001) and reduced stiffness parameter (SP-A1, p < 0.001). Multiple regression analysis showed that five parameters (HC-time, p < 0.001; PD, p < 0.001; DA-Max, p = 0.001; WEM-Max, p < 0.001; and SP-A1, p < 0.001) of Corvis ST were significantly correlated with AL, and one parameter (Corvis biomechanical index, p = 0.016) has significant relationship with SE. With the increase of myopia, significant changes in several corneal biomechanical parameters indicated a progressive decrease in corneal stiffness, independent of bIOP and CCT. Corneal biomechanical parameters may be predictors of scleral mechanical strength in high myopia, which has certain application value in clinical management of myopia. [ABSTRACT FROM AUTHOR]

Considering that people with Parkinson's disease (PD) experience challenges in the control of both balance and eye movements, this study investigated the effects of saccadic eye movements on body sway in people with PD in two bases of support positions (side-by-side and tandem stances). Ten people with PD and 11 healthy individuals performed (a) fixation; (b) horizontal saccadic eye movements to the right and left; and (c) vertical saccadic eye movements up and down. The protocol for each postural task consisted of one block of six trials, making a total of 12 trials. Body sway and gaze parameters were measured during the trials. In both people with PD and healthy individuals, anterior–posterior body sway was significantly reduced in horizontal saccadic eye movements in contrast to fixation, regardless of the body position (side-by-side and tandem stances). Furthermore, vertical saccadic eye movements increased the area of sway in contrast to horizontal ones (and not to fixation) in people with PD. In addition, people with PD showed a higher number of fixations in all experimental conditions, without changes in the mean duration of fixations in both body positions. In conclusion, individuals with PD can improve body sway by coupling eye movements and postural sway when performing horizontal saccadic eye movements but not when performing vertical saccadic eye movements. [ABSTRACT FROM AUTHOR]

Since game mechanics and their visual aspects have become more and more addictive, there is concern about the growing prevalence of Internet gaming disorder (IGD). In the current narrative review, we searched PubMed and Google Scholar databases for the keywords "igd biomarker gaming" and terms related to biomarker modalities. The biomarkers we found are grouped into several categories based on a measurement method and are discussed in the light of theoretical addiction models (tripartite neurocognitive model, I-PACE). Both theories point to gaming-related problems with salience and inhibition. The first dysfunction makes an individual more susceptible to game stimuli (raised reward seeking), and the second negatively impacts resistance to these stimuli (decreased cognitive control). The IGD patients' hypersensitivity to reward manifests mostly in ventral striatum (VS) measurements. However, there is also empirical support for a ventral-to-dorsal striatal shift and transition from goal-directed to habitual behaviors. The deficits in executive control are demonstrated in parameters related to the prefrontal cortex (PFC), especially the dorsolateral prefrontal cortex (DLPFC). In general, the connection of PFC with reward under cortex nuclei seems to be dysregulated. Other biomarkers include reduced P3 amplitudes, high-frequency heart rate variability (HRV), and the number of eye blinks and saccadic eye movements during the non-resting state. A few studies propose a diagnostic (multimodal) model of IGD. The current review also comments on inconsistencies in findings in the nucleus accumbens (NAcc), anterior cingulate cortex (ACC), and precuneus and makes suggestions for future IGD studies. [ABSTRACT FROM AUTHOR]

Noise is a ubiquitous component of motor systems that leads to behavioral variability of all types of movements. Nonetheless, systems-based models investigating human movements are generally deterministic and explain only the central tendencies like mean trajectories. In this paper, a novel approach to modeling kinematic variability of movements is presented and tested on the oculomotor system. This approach reconciles the two prominent philosophies of saccade control: displacement-based control versus velocity-based control. This was achieved by quantifying the variability in saccadic eye movements and developing a stochastic model of its control. The proposed stochastic dual model generated significantly better fits of inter-trial variances of the saccade trajectories compared to existing models. These results suggest that the saccadic system can flexibly use the information of both desired displacement and velocity for its control. This study presents a potential framework for investigating computational principles of motor control in the presence of noise utilizing stochastic modeling of kinematic variability. [ABSTRACT FROM AUTHOR]

This article discusses a case study of a patient with α-Methylacyl-CoA Racemase (AMACR) deficiency, a rare peroxisomal enzyme deficiency. The patient presented with various neurological symptoms, including ataxia, spasticity, and dystonia. The article explores the diverse clinical signs and manifestations of peroxisomal enzyme deficiencies, particularly focusing on neurological features such as encephalopathies, seizures, cerebellar signs, and tremor. The patient's unique neurological features expand the existing understanding of AMACR deficiency. The article provides a detailed account of the patient's medical history, examination findings, laboratory results, and genetic analysis that led to the diagnosis of AMACR deficiency. Additionally, the document discusses the controversial effectiveness of dietary restrictions in reducing phytanic acid intake for AMACR deficiency. It presents a case study of a patient who was unable to tolerate the diet and discontinued it. The document highlights the importance of considering AMACR deficiency in patients with undiagnosed cerebellar ataxia and seizure or atypical features. [Extracted from the article]

Evidence has demonstrated that athletes exhibit superior cognitive performance associated with executive control. In the oculomotor system, this function has been examined using the interleaved pro‐saccade and anti‐saccade task (IPAST), wherein participants, prior to target appearance, are instructed to either automatically look at the peripheral target (pro‐saccade) or suppress the automatic response and voluntarily look in the opposite direction (anti‐saccade). While the IPAST has provided much insight into sensorimotor and inhibitory processing, it has yet to be performed in athletes. Moreover, limited research has examined saccade metrics in athletes. Here, we examined saccade latency and movement kinematics in the IPAST among athletes (N = 40) and nonathletes (NON) (N = 40). Higher direction error rates were obtained in the anti‐saccade compared to the pro‐saccade condition, with no differences between athletes and NON noted. Significantly faster saccade latencies were observed in athletes compared to NON in both conditions, in addition to faster pro‐saccades compared to anti‐saccades. Furthermore, athletes showed significantly higher frequencies and faster latencies of express saccades compared to NON in correct pro‐saccades. Additionally, athletes exhibited significantly faster latencies of express saccades compared to NON in erroneous anti‐saccades. Differences in saccade metrics between athletes and NON were not seen. Overall, these findings demonstrate that athletes display altered saccade performance likely associated with sensorimotor and preparatory processing, highlighting the potential of using IPAST to objectively investigate sensorimotor and cognitive functions in athletes. [ABSTRACT FROM AUTHOR]

Background and Objectives: The diagnostic challenge of myasthenia gravis (MG) is exacerbated by the variable efficacy of current testing methodologies, necessitating innovative approaches to accurately identify the condition. This study aimed to assess ocular muscle fatigue in patients with MG using video-oculography (VOG) by examining repetitive saccadic eye movements and comparing these metrics to those of healthy control participants. Methods: This prospective, cross-sectional study was conducted at a tertiary care center and involved 62 patients diagnosed with MG (48 with ocular MG and 14 with generalized MG) and a control group of 31 healthy individuals, matched for age and sex. The assessment involved recording saccadic eye movements within a ± 15° range, both horizontally and vertically, at a rate of 15 saccades per minute over a 5-min period, resulting in 75 cycles. Participants were afforded a 3-min rest interval between each set to mitigate cumulative fatigue. The primary outcome was the detection of oculomotor fatigue, assessed through changes in saccadic waveforms, range, peak velocity, latency, and the duration from onset to target, with a focus on comparing the second saccade against the average of the last five saccades. Results: In the evaluation of repetitive saccadic movements, patients with MG exhibited a reduced saccadic range and a prolonged duration to reach the target, compared to healthy subjects. Furthermore, a significant elevation in the frequency of multistep saccades was observed among MG patients, with a marked rise observed over consecutive trials. Receiver operating characteristic (ROC) analysis revealed the discriminative performance of multistep saccade frequency, in conjunction with variations in saccadic range and duration from onset to target achievement between the second saccade and the mean of the final five saccades, as effective in distinguishing MG patients from healthy subjects. Although alterations in peak saccadic velocity and latency were less pronounced, they were nevertheless detectable. Discussion: The utilization of VOG for repetitive saccadic testing in the diagnosis of MG has demonstrated considerable diagnostic precision. This methodology affords significant accuracy in evaluating ocular muscle fatigue in MG patients, providing class III evidence supportive of its clinical application. [ABSTRACT FROM AUTHOR]

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 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 when 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. [ABSTRACT FROM AUTHOR]

Snakes are known for their unique abilities including infrared reception and their heavy reliance on heat sensors and vibrations. Infrared reception of snakes has gone under immense investigation; however, there have been very few studies that elaborate on their capacity to see. The goal of this study is to determine visual acuity of ball pythons (Python regius) by observing their optokinetic response (OKR). The OKR is a series of rapid saccadic and smooth pursuit movements of the eyes. It has been used for decades to determine visual acuity in multiple species such as humans, rats, and other nonmammalian species such as zebrafish and box turtles. Past studies have discovered that birds, reptiles, and amphibians achieve gaze stabilization by head and body movements, whereas in mammals and fish, gaze stabilization is conducted by eye movements. In this study, ball pythons were placed in a clear tube in a dark room, and a spinning black and white grating was projected in front of them. The size, direction, and velocity of the grating was manipulated which allowed their visual acuity to be determined. Our hypothesis is that P. regius would have a poor OKR response with low visual acuity due to their heavy reliance on other senses. Results show that P. regius does respond to visual stimuli, shows ocular saccadic movement in the direction of their stimuli, and has a relatively poor visual acuity when compared to other previously studied reptiles. [ABSTRACT FROM AUTHOR]

Aim: This preliminary study investigated the differences in event-related potential and reaction time under two groups (athletes vs. non-athletes). Material and methods: The P300 was analyzed for Fz, Cz, and Pz electrodes in thirty-one healthy volunteers divided into two groups (volleyball athletes and non-athletes). In addition, the participants performed a saccadic eye movement task to measure reaction time. Results: The EEG analysis showed that the athletes, in comparison to the no-athletes, have differences in the P300 in the frontal area (p = 0.021). In relation to reaction time, the results show lower reaction time for athletes (p = 0.001). Conclusions: The volleyball athletes may present a greater allocation of attention during the execution of the inhibition task, since they have a lower reaction time for responses when compared to non-athletes. [ABSTRACT FROM AUTHOR]

SUMMARY: Eye Movement Desensitisation and Reprocessing (EMDR) is an established psychotherapy that utilises repetitive, bilateral stimulation, such as saccadic eye movements, to treat the symptoms associated with traumatic experiences. Much of the attention EMDR has received has focused on its use in treating post-traumatic stress disorder (PTSD), which has resulted in its inclusion in several treatment guidelines. There is, however, emerging evidence that suggests a promising role for EMDR in managing a wide range of other mental and physical health conditions. High-quality studies demonstrate the efficacy of EMDR in managing conditions such as anxiety disorders, obsessive–compulsive disorder, major depressive disorder and chronic pain. Preliminary studies have also investigated its use in conditions such as bipolar disorder, eating disorders, substance misuse, psychotic disorders and sleep disturbances. The major studies exploring these applications of EMDR, outside of PTSD, are reviewed in this article. [ABSTRACT FROM AUTHOR]

In the complex interplay between sensory and cognitive processes, the brain must sift through a flood of sensory data to pinpoint relevant signals. This selective mechanism is crucial for the effective control of behaviour, by allowing organisms to focus on important tasks and blocking out distractions. The Inhibition of a Recent Distractor (IRD) Task examines this selection process by exploring how inhibiting distractors influences subsequent eye movements towards an object in the visual environment. In a series of experiments, research by Crawford et al. (2005a) demonstrated a delayed response to a target appearing at the location that was previously occupied by a distractor, demonstrating a legacy inhibition exerted by the distractor on the spatial location of the upcoming target. This study aimed to replicate this effect and to investigate any potential constraints when multiple distractors are presented. Exploring whether the effect is observed in more ecologically relevant scenarios with multiple distractors is crucial for assessing the extent to which it can be applied to a broader range of environments. Experiment 1 successfully replicated the effect, showing a significant IRD effect only with a single distractor. Experiments 2–5 explored a number of possible explanations for this phenomenon. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the effect of auditory working memory task on situation awareness (SA) and eye-movement patterns in complex dynamic environments. Background: Many human errors in aviation are caused by a lack of SA, and distraction from auditory secondary tasks is a serious threat to SA. However, it remains unclear how auditory working memory tasks affect SA and eye-movement patterns. Method: Participants (n = 28) were randomly allocated to two groups and received different periods of visual search training (short versus long). They subsequently completed a situation awareness measurement task in three auditory secondary task conditions (without secondary task, auditory calculation task, and auditory 2-back task). Eye-movement data were collected during the situation awareness measurement task. Results: The auditory 2-back task significantly reduced overall SA, Level 1 SA, dwell times, and total percentage of fixation time on task-related areas of interests in the SA measurement task. Overall SA and Level 3 SA were not reduced by the auditory 2-back task in individuals in the longer visual search training time condition. Conclusion: Auditory working memory load impairs SA in the perception and projection stage; however, greater experience can overcome impairment of SA in the projection stage. Application: This study provided possible approaches to preventing loss of SA: (1) improving crew members' communication skills to ensure the accurate and clear transmission of information, reducing the difficulty of processing information, and (2) providing targeted cognitive training tailored to each pilot's level of experience. [ABSTRACT FROM AUTHOR]

This study is crucial for improving unilateral spatial neglect (USN) treatments, focusing on comparing the effectiveness of computer-assisted cognitive rehabilitation (CACR) against conventional rehabilitation (CR) methods. It aimed to address a significant research gap and improve patient outcomes by evaluating the impact of CACR versus CR on visuospatial perception, visual field and attention, and visual memory in patients with USN. This study was a randomized controlled trial. Forty-five consecutive patients with USN from a university rehabilitation center were divided into two groups: 22 patients received CACR with Rehacom software, focusing on saccadic eye movement, visual field, and visual-motor coordination, while 23 underwent CR that combined hemispheric activation approach, mental imagery training, and vibration therapy. Assessments included the Motor-Free Visual Perception Test (MVPT), Line Bisection Test (LBT), Visual Span Test (VST), and Visual Recognition Test (VRT). The study employed ANCOVA and effect size calculations to evaluate the effectiveness of CACR compared to CR in treating patients with USN. Results indicated that CACR significantly outperformed CR in improving visuospatial perception, visual field, attention, and memory, showcasing its effectiveness in treating USN. These findings demonstrate the superiority of CACR over CR, particularly in enhancing visual memory and attention, as evidenced by the large effect size in VRT and moderate effects in LBT and VST. This suggests CACR's potential as a more effective approach for rehabilitation in patients with USN due to brain injuries. [ABSTRACT FROM AUTHOR]

Background: Patients with chronic rhinosinusitis (CRS) can experience cognitive dysfunction. The literature on this topic mostly reflects patient‐reported measurements. Our goal was to assess cognitive function in patients with CRS using objective measures, including saccadic eye movements—a behavioral response reflecting cognitive and sensory information integration that is often compromised in conditions with impaired cognition. Methods: Participants (N = 24 with CRS, N = 23 non‐CRS healthy controls) enrolled from rhinology clinic underwent sinonasal evaluation, quality of life assessment (Sino‐nasal Outcome Test 22 [SNOT‐22]), and cognitive assessment with the Neuro‐QOL Cognitive Function‐Short Form, the Montreal Cognitive Assessment (MoCA), and recording of eye movements using video‐oculography. Results: Participants with CRS were more likely to report cognitive dysfunction (Neuro‐QOL; 45.8% vs. 8.7%; p = 0.005) and demonstrate mild or greater cognitive impairment (MoCA; 41.7% vs. 8.7%; p = 0.005) than controls. Additionally, participants with CRS performed worse on the MoCA overall and within the executive functioning and memory domains (all p < 0.05) and on the anti‐saccade (p = 0.014) and delay saccade (p = 0.044) eye movement tasks. Poorer performance on the MoCA (r = −0.422; p = 0.003) and the anti‐saccade (r = −0.347; p = 0.017) and delay saccade (r = −0.419; p = 0.004) eye movement tasks correlated with worse CRS severity according to SNOT‐22 scores. Conclusion: This study is the first to utilize objective eye movement assessments in addition to researcher‐administered cognitive testing in patients with CRS. These patients demonstrated a high prevalence of cognitive dysfunction, most notably within executive functioning and memory domains, with the degree of dysfunction correlating with the severity of CRS. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) presents a range of challenges, including heightened sensory sensitivities. Here, we examine the idea that sensory overload in ASD may be linked to issues with efference copy mechanisms, which predict the sensory outcomes of self-generated actions, such as eye movements. Efference copies play a vital role in maintaining visual and motor stability. Disrupted efference copies hinder precise predictions, leading to increased reliance on actual feedback and potential distortions in perceptions across eye movements. In our first experiment, we tested how well healthy individuals with varying levels of autistic traits updated their mental map after making eye movements. We found that those with more autistic traits had difficulty using information from their eye movements to update the spatial representation of their mental map, resulting in significant errors in object localization. In the second experiment, we looked at how participants perceived an object displacement after making eye movements. Using a trans-saccadic spatial updating task, we found that those with higher autism scores exhibited a greater bias, indicating under-compensation of eye movements and a failure to maintain spatial stability during saccades. Overall, our study underscores efference copy's vital role in visuo-motor stability, aligning with Bayesian theories of autism, potentially informing interventions for improved action- perception integration in autism. [ABSTRACT FROM AUTHOR]

Oculomotor deficits are common in hereditary ataxia, but disproportionally neglected in clinical ataxia scales and as outcome measures for interventional trials. Quantitative assessment of oculomotor function has become increasingly available and thus applicable in multicenter trials and offers the opportunity to capture severity and progression of oculomotor impairment in a sensitive and reliable manner. In this consensus paper of the Ataxia Global Initiative Working Group On Digital Oculomotor Biomarkers, based on a systematic literature review, we propose harmonized methodology and measurement parameters for the quantitative assessment of oculomotor function in natural-history studies and clinical trials in hereditary ataxia. MEDLINE was searched for articles reporting on oculomotor/vestibular properties in ataxia patients and a study-tailored quality-assessment was performed. One-hundred-and-seventeen articles reporting on subjects with genetically confirmed (n=1134) or suspected hereditary ataxia (n=198), and degenerative ataxias with sporadic presentation (n=480) were included and subject to data extraction. Based on robust discrimination from controls, correlation with disease-severity, sensitivity to change, and feasibility in international multicenter settings as prerequisite for clinical trials, we prioritize a core-set of five eye-movement types: (i) pursuit eye movements, (ii) saccadic eye movements, (iii) fixation, (iv) eccentric gaze holding, and (v) rotational vestibulo-ocular reflex. We provide detailed guidelines for their acquisition, and recommendations on the quantitative parameters to extract. Limitations include low study quality, heterogeneity in patient populations, and lack of longitudinal studies. Standardization of quantitative oculomotor assessments will facilitate their implementation, interpretation, and validation in clinical trials, and ultimately advance our understanding of the evolution of oculomotor network dysfunction in hereditary ataxias. [ABSTRACT FROM AUTHOR]

Introduction: Deceleration of vertical saccades, an early and characteristic finding of Niemann-Pick Type C (NP-C), may help diagnosis. Our aim in this study was to demonstrate the role of video-oculography (VOG), in the differential diagnosis of ataxia syndromes, particularly of NP-C, using this technique in the evaluation of saccadic velocity and smooth pursuit gain of ataxia patients. Methods: We recruited consecutive 50 ataxia patients and 50 healthy control subjects who were age and sex-matched with the patient group. Saccadic eye movements and smooth pursuit eye movements for different angles and different directions from patients and healthy subjects were recorded by using VOG. Results: Saccadic eye movement velocity and smooth pursuit gain values of the patients were significantly lower in all directions and at all angles as compared to healthy subjects. In the patient group, 3 cases out of 50 were selected as suspected NP-C, based on the dissociation between their markedly impaired vertical saccadic velocity and near normal to slightly impaired horizontal one and relatively intact smooth pursuit eye movements; the diagnoses in all 3 cases were confirmed with positive genetic testing, and thereupon Miglustat treatment was started. Conclusion: Our findings support that cerebellar pathology in degenerative ataxia patients is associated with both impaired saccadic velocity and smooth pursuit gain, whereas in NP-C, only the impaired vertical saccades as opposed to relatively preserved other eye movements are seemingly a diagnostic marker for the entity. We conclude that recording of eye movements could be useful for differential diagnosis and monitorization of the treatment of ataxia syndromes as an easy and objective method. [ABSTRACT FROM AUTHOR]

Perceptually natural standard‐dynamic‐range (SDR) images reproduced under normal viewing conditions should retain enough information for the human observer to estimate the time at which the actual high‐dynamic‐range (HDR) scene was captured without recourse to artificial information. Currently, both global‐ and local‐tone mapping operators (TMOs) seem to have comparable levels of performance. Therefore, we first consider the constraints created in the actual human visual system by eye movement, and buttress a hypothesis with a demonstration. We briefly review the imperceptible illuminance effects yielded by the personal circadian clock suggested by chronophysiological research and other related effects, because our previous study suggested that the characteristics of the human visual system dynamically varies depending on the individual's circadian pattern. Finally, we conduct two psychophysical experiments based on the hypothesis that the human visual system employs several global TMOs at the first stage for information compression that depend on individual‐circadian‐visual‐features (ICVF). The results suggest that (1) no participant can perceive actual‐capture‐time (ACT) and (2) sensitive observers can discriminate reproduced images based on virtual‐shooting‐time (VST) effects induced by different types of global TMOs. We also discover that the VST‐based discrimination differs widely among people, but most are unaware of this effect as evidenced by daily conversations. [ABSTRACT FROM AUTHOR]

Our eyes execute rapid, directional movements known as saccades, occurring several times per second, to focus on objects of interest in our environment. During these movements, visual sensitivity is temporarily reduced. Despite numerous studies on this topic, the underlying mechanism remains elusive, including a lingering debate on whether saccadic suppression affects the parvocellular visual pathway. To address this issue, we conducted a study employing steady-state visual evoked potentials (SSVEPs) elicited by chromatic and luminance stimuli while observers performed saccadic eye movements. We also employed an innovative analysis pipeline to enhance the signal-to-noise ratio, yielding superior results compared to the previous method. Our findings revealed a clear suppression effect on SSVEP signals during saccades compared to fixation periods. Notably, this suppression effect was comparable for both chromatic and luminance stimuli. We went further to measure the suppression effect across various contrast levels, which enabled us to model SSVEP responses with contrast response functions. The results suggest that saccades primarily reduce response gain without significantly affecting contrast gain and that this reduction applies uniformly to both chromatic and luminance pathways. In summary, our study provides robust evidence that saccades similarly suppress visual processing in both the parvocellular and magnocellular pathways within the human early visual cortex, as indicated by SSVEP responses. The observation that saccadic eye movements impact response gain rather than contrast gain implies that they influence visual processing through a multiplicative mechanism. NEW & NOTEWORTHY: The present study demonstrates that saccadic eye movements reduce the processing of both luminance and chromatic stimuli in the early visual cortex of humans. By modeling the contrast response function, the study further shows that saccades affect visual processing by reducing the response gain rather than altering the contrast gain, suggesting that a multiplicative mechanism of visual attenuation affects both parvocellular and magnocellular pathways. [ABSTRACT FROM AUTHOR]

Saccadic eye movements enable us to search for the target of interest in a crowded scene or, in the case of goal-directed saccades, to simply bring the image of the peripheral target to the very centre of the fovea. This mechanism extends the use of the superior image processing performance of the fovea over a large visual field. We know that visual information is processed quickly at the end of each saccade but estimates of the times involved remain controversial. This study aims to investigate the processing of visual information during post fixation oscillations of the eyeball. A new psychophysical test measures the combined eye movement response latencies, including fixation duration and visual processing times. When the test is used in conjunction with an eye tracker, each component that makes up the 'integrated saccade latency' time, from the onset of the peripheral stimulus to the correct interpretation of the information carried by the stimulus, can be measured and the discrete components delineated. The results show that the time required to process and encode the stimulus attribute of interest at the end of a saccade is longer than the time needed to carry out the same task in the absence of an eye movement. We propose two principal hypotheses, each of which can account for this finding. 1. The known inhibition of afferent retinal signals during fast eye movements extends beyond the end point of the saccade. 2. The extended visual processing times measured when saccades are involved are caused by the transient loss of spatial resolution due to eyeball instability during post-saccadic oscillations. The latter can best be described as retinal image smear with greater loss of spatial resolution expected for stimuli of low luminance contrast. [ABSTRACT FROM AUTHOR]

Whether a saccade is accurate and has reached the target cannot be evaluated during its execution, but relies on post-saccadic feedback. If the eye has missed the target object, a secondary corrective saccade has to be made to align the fovea with the target. If a systematic post-saccadic error occurs, adaptive changes to the oculomotor behavior are made, such as shortening or lengthening the saccade amplitude. Systematic post-saccadic errors are typically attributed internally to erroneous motor commands. The corresponding adaptive changes to the motor command reduce the error and the need for secondary corrective saccades, and, in doing so, restore accuracy and efficiency. However, adaptive changes to the oculomotor behavior also occur if a change in saccade amplitude is beneficial for task performance, or if it is rewarded. Oculomotor learning thus is more complex than reducing a post-saccadic position error. In the current study, we used a novel oculomotor learning paradigm and investigated whether human participants are able to adapt their oculomotor behavior to improve task performance even when they attribute the error externally. The task was to indicate the intended target object among several objects to a simulated human-machine interface by making eye movements. The participants were informed that the system itself could make errors. The decoding process depended on a distorted landing point of the saccade, resulting in decoding errors. Two different types of visual feedback were added to the post-saccadic scene and we compared how participants used the different feedback types to adjust their oculomotor behavior to avoid errors. We found that task performance improved over time, regardless of the type of feedback. Thus, error feedback from the simulated human-machine interface was used for post-saccadic error evaluation. This indicates that 1) artificial visual feedback signals and 2) externally caused errors might drive adaptive changes to oculomotor behavior. [ABSTRACT FROM AUTHOR]

In primates, foveal and peripheral vision have distinct neural architectures and functions. However, it has been debated if selective attention operates via the same or different neural mechanisms across eccentricities. We tested these alternative accounts by examining the effects of selective attention on the steady-state visually evoked potential (SSVEP) and the fronto-parietal signal measured via EEG from human subjects performing a sustained visuospatial attention task. With a negligible level of eye movements, both SSVEP and SND exhibited the heterogeneous patterns of attentional modulations across eccentricities. Specifically, the attentional modulations of these signals peaked at the parafoveal locations and such modulations wore off as visual stimuli appeared closer to the fovea or further away towards the periphery. However, with a relatively higher level of eye movements, the heterogeneous patterns of attentional modulations of these neural signals were less robust. These data demonstrate that the top-down influence of covert visuospatial attention on early sensory processing in human cortex depends on eccentricity and the level of saccadic responses. Taken together, the results suggest that sustained visuospatial attention operates differently across different eccentric locations, providing new understanding of how attention augments sensory representations regardless of where the attended stimulus appears. [ABSTRACT FROM AUTHOR]

Investigation of visual illusions helps us understand how we process visual information. For example, face pareidolia, the misperception of illusory faces in objects, could be used to understand how we process real faces. However, it remains unclear whether this illusion emerges from errors in face detection or from slower, cognitive processes. Here, our logic is straightforward; if examples of face pareidolia activate the mechanisms that rapidly detect faces in visual environments, then participants will look at objects more quickly when the objects also contain illusory faces. To test this hypothesis, we sampled continuous eye movements during a fast saccadic choice task—participants were required to select either faces or food items. During this task, pairs of stimuli were positioned close to the initial fixation point or further away, in the periphery. As expected, the participants were faster to look at face targets than food targets. Importantly, we also discovered an advantage for food items with illusory faces but, this advantage was limited to the peripheral condition. These findings are among the first to demonstrate that the face pareidolia illusion persists in the periphery and, thus, it is likely to be a consequence of erroneous face detection. [ABSTRACT FROM AUTHOR]

Objective: Investigate the effect of cumulative head impacts on saccade latency and errors, measured across two successive football seasons. Design: Participants were acquired from a sample of convenience—one Canadian university football team. Head impacts were collected during training camp, practices, eight regular season games, and four playoff games in each season. Saccade measurements were collected at five time points—before and after training camp, at midseason, after regular season, and after playoffs. Setting: Two seasons following players from a single USports football team during practices and games. Participants: Players who completed a baseline saccade measurement and a minimum of one follow-up measurement were included in the study. A total of 127 players were monitored across two competitive seasons, including 61 players who participated in both seasons. Independent Variables: Head impact measurements were collected using helmet-mounted sensors. Main Outcome Measures: Saccade latency and number of errors were measured using high-speed video or electro-oculography. Results: On average, each head impact increased prosaccade latency by 5.16 × 10−3 ms (95% confidence interval [CI], 2.26 × 10−4-1.00 × 10−2, P = 0.03) and antisaccade latency by 5.74 × 10−3 ms (95% CI, 7.18 × 10−4-1.06 × 10−2, P = 0.02). These latency increases did not decrease between the two seasons; in fact, prosaccade latencies were 23.20 ms longer (95% CI, 19.40-27.14, P < 0.001) at the second season's baseline measurement than the first. The number of saccade errors was not affected by cumulative head impacts. Conclusions: Repetitive head impacts in Canadian university football result in cumulative declines in brain function as measured by saccade performance. [ABSTRACT FROM AUTHOR]

A form of repetition blindness in visually unimpaired individuals was found for objects presented during saccades. Observers were asked to draw their percepts after making saccades across an LED strip that "painted" an image on their retinas by presenting sequential columns of a bitmap at a speed to match a 30-degree saccade. During experimental trials, repetitions of a single letter (either "A," "X," "H," or "V") were presented across saccades. Although an average of six letters were presented across each saccade, observers typically indicated perceiving only a single instance of the letter in their drawings. This inability to perceive multiple instances of a letter was not due to a limited region of attentional processing, as it only attained for multiple instances along the axis of the saccade—horizontal saccades did not affect perception of multiple letters along the vertical axis. This effect is likely due to selective suppression of visual areas during saccades. [ABSTRACT FROM AUTHOR]

Background: Multiple system atrophy (MSA) is a neurodegenerative disease that progresses rapidly and has a poor prognosis. This study aimed to assess the value of video oculomotor evaluation (VOE) in the differential diagnosis of MSA and Parkinson's disease (PD). Methods: In total, 28 patients with MSA, 31 patients with PD, and 30 age‐ and sex‐matched healthy controls (HC) were screened and included in this study. The evaluation consisted of a gaze‐holding test, smooth pursuit eye movement (SPEM), random saccade, and optokinetic nystagmus (OKN). Results: The MSA and PD groups had more abnormalities and decreased SPEM gain than the HC group (64.29%, 35.48%, 10%, p <.001). The SPEM gain in the MSA group was significantly lower than that in the PD group at specific frequencies. Patients with MSA and PD showed prolonged latencies in all saccade directions compared with those with HC. However, the two diseases had no significant differences in the saccade parameters. The OKN gain gradually decreased from the HC to the PD and the MSA groups (p <.05). Compared with the PD group, the gain in the MSA group was further decreased in the OKN test at 30°/s (Left, p =.010; Right p =.016). Receiver operating characteristic curves showed that the combination of oculomotor parameters with age and course of disease could aid in the differential diagnosis of patients with MSA and PD, with a sensitivity of 89.29% and a specificity of 70.97%. Conclusions: The combination of oculomotor parameters and clinical data may aid in the differential diagnosis of MSA and PD. Furthermore, VOE is vital in the identification of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) dementia is a degenerative illness that is characterized by a gradual decline in cognitive abilities. Amnestic mild cognitive impairment (aMCI) is seen as a precursor to AD. The changes in antisaccade performance that can be seen in MCI may provide important clues in the early detection of AD. Therefore, the antisaccade deficits in AD and aMCI remain a research question. This study aimed to examine antisaccade responses and the relationship between antisaccade and cognitive function in AD, aMCI, and healthy controls (HC). This study included 30 patients with early-stage AD, 34 with aMCI, and 32 HC. Patients with AD showed higher rates of uncorrected error, anticipatory saccades and corrected errors, as well as decreased correct saccade rates, and shortened saccade latency compared to aMCI and HC in this study. Patients with aMCI exhibited increased rates of express saccades relative to HC. The antisaccade task and cognitive domains were found to be significantly related. Our study showed that the rate of correct saccades has the capacity to distinguish AD from HC with 87% sensitivity and 86% specificity (AUC = 0.93, p < 0.001). In addition, the rate of uncorrected errors was found to be capable of distinguishing AD from HC with 84% sensitivity and 83% specificity (AUC = 0.91, p < 0.001). This study presented promising findings that these parameters can be used clinically to differentiate AD and aMCI from healthy older individuals. [ABSTRACT FROM AUTHOR]

Vision-related problems can be part of longstanding sequelae after COVID-19 and hamper the return to work and daily activities. Knowledge about symptoms, visual, and oculomotor dysfunctions is however scarce, particularly for non-hospitalised patients. Clinically applicable tools are needed as support in the assessment and determination of intervention needs. The purpose of this study was to evaluate vision-related symptoms, assess visual and oculomotor function, and to test the clinical assessment of saccadic eye movements and sensitivity to visual motion in non-hospitalised post-COVID-19 outpatients. The patients (n = 38) in this observational cohort study were recruited from a post-COVID-19 clinic and had been referred for neurocognitive assessment. Patients who reported vision-related symptoms reading problems and intolerance to movement in the environment were examined. A structured symptom assessment and a comprehensive vision examination were undertaken, and saccadic eye movements and visual motion sensitivity were assessed. High symptom scores (26–60%) and prevalence of visual function impairments were observed. An increased symptom score when reading was associated with less efficient saccadic eye movement behaviour (p < 0.001) and binocular dysfunction (p = 0.029). Patients with severe symptoms in visually busy places scored significantly higher on the Visual Motion Sensitivity Clinical Test Protocol (p = 0.029). Vision-related symptoms and impairments were prevalent in the study group. The Developmental Eye Movement Test and the Visual Motion Sensitivity Clinical Test Protocol showed promise for clinical assessment of saccadic performance and sensitivity to movement in the environment. Further study will be required to explore the utility of these tools. [ABSTRACT FROM AUTHOR]

Background and Aim: Several laboratory tools are used to evaluate balance disorders but, there is still no screening test to determine the site and the severity of the lesion. The aim was to investigate whether video Head Impulse Test (vHIT) can be used as a screening test in patients with chronic or recurrent vertigo and dizziness. Methods: The files of 965 patients who were followed up in our vertigo outpatient clinic were reviewed retrospectively. Vestibulo-Ocular Reflex (VOR) gains and saccadic movements of the right and left lateral canals in the vHIT test, and Canal Paresis (CP) in the Caloric Testing (CT) were noted. Results: A total of 325 patients were included in our study. In CT results, the group that CP was most frequently detected was Menière's Disease (MD) group (71 patients (74.7%). While vHIT results were found to be pathological in the vast majority of patients in the Vestibular Neuritis (VN) group (72.7%), the results were found to be normal at the highest rate in the vestibular migraine group (77.9%). Correlation analysis showed a significant but weak correlation between the degree of CP in the CT and the VOR gains of the lateral canals in vHIT in all groups. Conclusion: Although it has high sensitivity in cases with VN and vestibulopathy, we think that vHIT cannot be used as a screening tool in patients with vertigo, especially for chronic cases, since its sensitivity rate differs in the long term according to the cause of the disease. [ABSTRACT FROM AUTHOR]

Objectives: Patients with vestibular migraine (VM) show a significant decrease in gray matter cortical regions associated with pain and vestibular processing, as revealed by head functional magnetic resonance imaging. We predict that these changes can be reflected in intentional saccadic eye movements. This study aims to establish whether there are abnormalities in intentional saccadic eye movements in patients with VM. Subjects and Methods: This is a retrospective study involving two groups of patients, including 39 patients in the VM group and 38 patients in the control group. The VM group and control group matched for age and gender were collected from Beijing Luhe Hospital affiliated with Capital Medical University, between June 2021 and May 2022. All patients received antisaccade (AS) and memory-guided saccade (MGS) tasks. Results: Compared with the control group, there were no significant differences in VM group in latency and gain of ASs. However, there were significant differences in the AS error rate between the two groups (right side 44% in VM and 32% in the control group; P = 0.041, left side 41% in VM and 29% in the control group; P = 0.011), with higher error rates observed in the VM group compared to the control group. Compared with the control group, there were no significant differences in the accuracy and final eye position gain of MGSs. However, there were significant differences in the valid saccade accurate percentage of MGS between the two groups (right side 59% in VM and 81% in the control group; P = 0.009, left side 59% in VM and 90% in the control group; P = 0.012), with lower accurate percentages observed in patients with VM compared to the normal control group. Furthermore, the latency of MGS between the two groups differed significantly (right side 677 ms in VM and 491.5 ms in the control group; P = 0.024, left side 670 ms in VM and 555 ms in the control group; P = 0.024), with longer latencies observed in patients with VM compared to normal control group. The results showed that VM disease duration had a positive correlation with the AS error rate (right: P =0.043, r = 0.326; left: P =0.000, r = 0.535). Conclusions: We found abnormalities in the AS and MGS tasks in patients with VM. The duration of VM is positively correlated with the AS error rate. Our study discovered that in addition to headache, dizziness, and autonomic symptoms, VM patients also exhibit impaired intentional saccadic eye movements, which may be related to reduced gray matter volume involved in pain and vestibular processing and cognitive impairment in VM patients. [ABSTRACT FROM AUTHOR]

With every saccadic eye movement, humans bring new information into their fovea to be processed with high visual acuity. Notably, perception is enhanced already before a relevant item is foveated: During saccade preparation, presaccadic attention shifts to the upcoming fixation location, which can be measured via behavioral correlates such as enhanced visual performance or modulations of sensory feature tuning. The coupling between saccadic eye movements and attention is assumed to be robust and mandatory and considered a mechanism facilitating the integration of pre- and postsaccadic information. However, until recently it had not been investigated as a function of saccade direction. Here, we measured contrast response functions during fixation and saccade preparation in male and female observers and found that the pronounced response gain benefit typically elicited by presaccadic attention is selectively lacking before upward saccades at the group level--some observers even showed a cost. Individual observer's sensitivity before upward saccades was negatively related to their amount of surface area in primary visual cortex representing the saccade target, suggesting a potential compensatory mechanism that optimizes the use of the limited neural resources processing the upper vertical meridian. Our results raise the question of how perceptual continuity is achieved and how upward saccades can be accurately targeted despite the lack of--theoretically required--presaccadic attention. [ABSTRACT FROM AUTHOR]

Quantifying saccadic eye movements can assist in identifying dysfunctional brain networks in both healthy and diseased people. Infrared Oculography is a simple and non-invasive approach to capturing and quantifying saccades, providing information that might aid in diagnosis and outcome assessments. The effect of spinal manipulation on quantified saccadic performance parameters has not been fully studied despite known post-manipulative effects on the brain and brainstem regions controlling them. This case study investigates spinal manipulation's immediate and long-term effects on saccadic eye movements by quantifying the saccades of a male patient diagnosed with post-concussion syndrome. The patient performed horizontal saccades that were quantified before and immediately following cervical spinal manipulation both at the case study's start and following a 2-week interim, during which the subject received six manipulative treatments. Immediate and long-term post-manipulative effects were observed, and the results revealed various post-manipulative effects across all quantified parameters in addition to between right and leftward saccades. The immediate post-manipulative effect was greatest at the case study's onset, while the long-term right and leftward saccadic symmetry were most affected. The observations in this case study demonstrate that cervical spinal manipulation influences saccadic eye movements, providing new insights into its central neurological effects and therapeutic applications beyond its most commonly known use in pain management. More importantly, it encourages scientists to undertake further clinical investigations on wider scales. [ABSTRACT FROM AUTHOR]

Early detection of dyslexia and learning disorders is vital for avoiding a learning disability, as well as supporting dyslexic students by tailoring academic programs to their needs. Several studies have investigated using supervised algorithms to screen dyslexia vs. control subjects; however, the data size and the conditions of data acquisition were their most significant limitation. In the current study, we leverage a large dataset, containing 4243 time series of eye movement records from children across Europe. These datasets were derived from various tests such as saccade, vergence, and reading tasks. Furthermore, our methods were evaluated with realistic test data, including real-life biases such as noise, eye tracking misalignment, and similar pathologies among non-scholar difficulty classes. In addition, we present a novel convolutional neural network architecture, adapted to our time series classification problem, that is intended to generalize on a small annotated dataset and to handle a high-resolution signal (1024 point). Our architecture achieved a precision of 80.20% and a recall of 75.1%, when trained on the vergence dataset, and a precision of 77.2% and a recall of 77.5% when trained on the saccade dataset. Finally, we performed a comparison using our ML approach, a second architecture developed for a similar problem, and two other methods that we investigated that use deep learning algorithms to predict dyslexia. [ABSTRACT FROM AUTHOR]

Introduction: Pathophysiological theories of schizophrenia (SZ) symptoms posit an abnormality in using predictions to guide behavior. One such prediction is based on imminent movements, via corollary discharge signals (CD) that relay information about planned movement kinematics to sensory brain regions. Empirical evidence suggests a reduced influence of sensorimotor predictions in individuals with SZ within multiple sensory systems, including in the visual system. One function of CD in the visual system is to selectively enhance visual sensitivity at the location of planned eye movements (pre‐saccadic attention), thus enabling a prediction of the to‐be‐foveated stimulus. We expected pre‐saccadic attention shifts to be less pronounced in individuals with SZ than in healthy controls (HC), resulting in unexpected sensory consequences of eye movements, which may relate to symptoms than can be explained in the context of altered allocation of attention. Methods: We examined this question by testing 30 SZ and 30 HC on a pre‐saccadic attention task. On each trial participants made a saccade to a cued location in an array of four stimuli. A discrimination target that was either congruent or incongruent with the cued location was briefly presented after the cue, during saccade preparation. Pre‐saccadic attention was quantified by comparing accuracy on congruent trials to incongruent trials within the interval preceding the saccade. Results: Although SZs were less accurate overall, the magnitude of the pre‐saccadic attention effect generally did not differ across groups nor show a convincing relationship with symptom severity. We did, however, observe that SZ had reduced pre‐saccadic attention effects when the discrimination target (probe) was presented at early stages of saccade planning, when pre‐saccadic attention effects first emerged in HC. Conclusion: These findings suggest generally intact pre‐saccadic shifts of attention in SZ, albeit slightly delayed. Results contribute to our understanding of altered sensory predictions in people with schizophrenia. [ABSTRACT FROM AUTHOR]

The article comments on a study which investigated visual sensitivity in the human visual cortex and compared saccadic suppression strengths with luminance versus color contrasts. It points out the clearer saccadic suppression effect with the introduction of signal-to-use ratio in the steady-state visually evoked potential signal. It suggests the potential suppression of early visual system in the temporal vicinity of saccades and not just the magnocellular visual processing pathway.

The article discusses the relationship between covert attention (attention without moving the gaze) and intentional eye movements known as saccades. The study found that covert attention to a peripheral object influenced subsequent saccades towards or away from the object. The researchers also discovered that the brightness of stimuli affected the automatic capture of gaze and that this capture was suppressed afterwards, indicating the presence of independent mechanisms for saccade control. The findings suggest that saccades depend on where voluntary attention is deployed beforehand but can be quickly directed elsewhere. [Extracted from the article]

The article discusses the coordination of eye and hand movements in humans during discrete and continuous actions. The authors conducted a study to investigate how eye and hand movements transition between these two types of movements. They found that there is a strong coupling between eye and hand movements, with tracking accuracy being highest when both effectors were used together. The study provides evidence for the coordination of eye and hand movements during visually guided actions and bridges the gap between research on continuous and discrete movements. The authors suggest that future studies should explore the role of target kinematics, predictability, and biomechanical costs in eye-hand coordination. [Extracted from the article]

We investigated gaze behavior of expert goalkeepers during the prediction of penalty kicks in different spatiotemporal constraints: penalties taken from 11 and 6 m. From 11 m, goalkeepers were more successful in predicting ball direction, with longer movement time initiation and a visual strategy with more fixations and greater saccade rates than penalties from 6 m, where they exhibited fewer fixations with higher microsaccade rates. As long as the opponent's distance is large and time pressure low, gaze can be frequently shifted between the kicker's body and the ball, due to the low cost of saccades. Conversely, when the objects are close, there is increased reliance on foveal and parafoveal information. In conclusion, when the spatiotemporal constraint is less severe, goalkeepers adopt a visual strategy with more fixations and small saccades. When the spatiotemporal constraint is more severe, they rely on peripheral vision to monitor kickers' movements through the use of microsaccades. [ABSTRACT FROM AUTHOR]

Internal models are essential for the production of accurate movements. The accuracy of saccadic eye movements is thought to be mediated by an internal model of oculomotor mechanics encoded in the cerebellum. The cerebellum may also be part of a feedback loop that predicts the displacement of the eyes and compares it to the desired displacement in real time to ensure that saccades land on target. To investigate the role of the cerebellum in these two aspects of saccade production, we delivered saccade-triggered light pulses to channelrhodopsin-2-expressing Purkinje cells in the oculomotor vermis (OMV) of two male macaque monkeys. Light pulses delivered during the acceleration phase of ipsiversive saccades slowed the deceleration phase. The long latency of these effects and their scaling with light pulse duration are consistent with an integration of neural signals at or downstreamof the stimulation site. In contrast, light pulses delivered during contraversive saccades reduced saccade velocity at short latency and were followed by a compensatory reacceleration which caused gaze to land on or near the target. We conclude that the contribution of the OMV to saccade production depends on saccade direction; the ipsilateral OMV is part of a forward model that predicts eye displacement, whereas the contralateral OMV is part of an inverse model that creates the force required to move the eyes with optimal peak velocity for the intended displacement. [ABSTRACT FROM AUTHOR]