Ocular Fixation Research Articles

The agreement between the Irvine 4 diopter prism test and assessment of ocular fixation in microtropia with identity

ABSTRACT Microtropia describes a primary ocular deviation of less than 10 prism diopters associated with harmonious anomalous retinal correspondence and reduced stereopsis. It is routinely accepted that children with microtropia are less likely to achieve equal vision following occlusion therapy than those with bifoveal fixation. The most commonly used methods of diagnosing a microtropia are the 4 diopter prism test (4∆PT) and assessment of ocular fixation. This study examines the agreement between the two tests. One hundred and twelve typically developing children without a manifest strabismus who were able to undertake a linear visual acuity test and had two or more lines of anisoacuity following refractive adaption to their full cycloplegic correction underwent assessment of the 4∆PT and ocular fixation along with their routine orthoptic examination. One hundred and twelve children (46 boys and 66 girls) attending the Orthoptic department who fitted the above criteria were included in the analysis. The mean age at examination was 6 years. 80.3% had anisometropia of at least 1.25 diopters. The 4∆PT indicated a microtropia in 74 cases, whereas assessment of fixation indicated a microtropia in 68 cases. In 88 cases (78.6%), the results of the two tests agreed. Analysis found only moderate agreement between the two tests (k = 0.540 (CI 0.379–0.700)). Logistic regression analysis comparing those children where the two tests agreed with those where they disagreed found no difference in the level of anisoacuity (p = 0.7823), degree of anisometropia (p = 0.9385), the vision in the worst eye (p = 0.5260), the refractive error in the “worst” eye (p = 0.865), or the age at the time of testing (p = 0.4485) between the two groups. When assessing for a microtropia, it was found that not all children who elicit a central suppression response on the 4∆PT are found to be fixing eccentrically and vice versa. This could potentially have implications for the treatment of their amblyopia. It is important not to rely on just one test at one time to make the diagnosis of microtropia. Rather, if one or other test indicates a microtropia the first time they are attempted, this should be reassessed regularly as treatment progresses and certainly before treatment is stopped and suboptimal visual acuity is accepted.

Brazilian guidelines on the frequency of ophthalmic assessment and recommended examinations in healthy children younger than 5 years

To provide guidance on the frequency and components of eye examinations for healthy children aged 0 to 5 years. These guidelines were developed based on the medical literature and clinical experience of an expert committee. PubMed/Medline searches were performed, with selected publications not restricted to systematic reviews, randomized controlled trials, or observational studies. The Grading of Recommendations Assessment, Development, and Evaluation profile was applied when suitable, and for issues without scientific evidence, recommendations were based on expert consensus. Recommendations by the American Academy of Pediatrics, American Association of Pediatric Ophthalmology and Strabismus, American Academy of Ophthalmology, Royal College of Ophthalmologists, and Canadian Ophthalmological Society were also reviewed. The final guideline document was approved by the Brazilian Pediatric Ophthalmology Society and by the Brazilian Pediatric Society. Newborns must undergo the red reflex test and inspection of the eyes and adnexa by a pediatrician within 72 hours of life. The red reflex test should be repeated by the pediatrician during childcare consultations at least three times per year during the first 3 years of life. If feasible, a comprehensive ophthalmologic examination may be performed between 6 and 12 months of age. Until 36 months of age, the pediatrician should assess the infant's visual development milestones, age-appropriate assessment of visual function, ocular fixation, and eye alignment. At least one comprehensive ophthalmologic examination should be performed at 3 to 5 years of age. The examination should minimally include inspection of the eyes and adnexa, age-appropriate visual function assessment, evaluations of ocular motility and alignment (cover tests), cycloplegic refraction, and dilated fundus. Guidelines concerning the frequency of ophthalmic assessment are important tools for directing physicians regarding best practices that avoid treatable vision problems that affect children's development, school, and social performance and cause unnecessary permanent vision loss.

Prevalence and Characteristics of Physiological Gaze-Evoked and Rebound Nystagmus: Implications for Testing Their Pathological Counterparts.

Objective: Cerebellar diseases frequently affect the ocular motor neural velocity-to-position integrator by increasing its leakiness and thereby causing gaze-evoked nystagmus (GEN) and rebound nystagmus (RN). Minor leakiness is physiological and occasionally causes GEN in healthy humans. We aimed to evaluate the characteristics of GEN/RN in healthy subjects for better differentiation between physiological and pathological GEN/RN.Methods: Using video-oculography, eye position was measured in 14 healthy humans at straight ahead eye position before and after, and during 30 s of ocular fixation at 4 horizontal eccentric targets between 30° and 45°. We determined the eye drift velocity and the prevalence of nystagmus before/during/after eccentric fixation.Results: Eye drift velocities during (range: 0.62 ± 0.53°/s to 1.78 ± 0.69°/s) and after eccentric gaze (range: 0.28 ± 0.52°/s to 1.48 ± 1.02°/s) increased with the amount of gaze eccentricity (30°-45°). During continuous eccentric gaze, eye drift velocities decreased by 0.41 ± 0.18°/s at 30°, and 0.84 ± 0.38°/s at 45° gaze eccentricity. GEN was elicited in 71% of subjects at 30° gaze eccentricity. Twenty-one percent showed RN thereafter. This prevalence increased to 100% (GEN)/72% (RN) at 45° gaze eccentricity. RN found after 30° gaze eccentricity was of low velocity (0.82 ± 0.21°/s) and occurred after minor drift velocity decrease during prior eccentric gaze (0.43 ± 0.15°/s).Conclusion: GEN and RN should be tested using horizontal gaze eccentricities of <30°, since most healthy subjects physiologically show GEN and RN at higher eccentricities. In case of an uncertain result, both the reduction of eye drift velocity during eccentric gaze and the velocity of RN can be analyzed to distinguish physiological from pathological nystagmus.

Oculomotor abnormalities in patients with Parkinson's disease and progressive supranuclear palsy

Background: Deficits in the ocular fixation and gaze control to be key for Parkinsonism diagnosis. We aimed to find out the possible oculomotor differences between patients with idiopathic Parkinson's disease (PD) and progressive supranuclear palsy (PSP).

Ocular fixation and macular integrity by microperimetry in multiple sclerosis.

To characterize the fixation and macular integrity of subjects with multiple sclerosis (MS) with and without previous optic neuritis (ON) using microperimetry (MP). Fifty-five eyes of MS patients, subdivided into three groups (28 eyes without ON, 16 with previous ON, and 11 eyes with previous ON in the contralateral eye), and 43 healthy eyes were enrolled (January-November 2018). All cases were evaluated using the MAIA microperimeter (Centervue), analyzing the following parameters: average macular threshold (AT), fixation indexes (P1 and P2), bivariate contour ellipse area (BCEA) for 95% and 63% of points, and horizontal (H) and vertical (V) axes of the ellipse of fixation. All MS groups showed a significant reduced AT compared with the control group (p < 0.001). This reduction was more representative (p < 0.001) in eyes with previous ON. No statistically significant differences were found between MS patients with and without previous ON (p > 0.05). Mean AT was correlated with the examination time in all three groups (between ρ = - 0.798 p < 0.001 and ρ = - 0.49 p < 0.001). Significant differences in fixation parameters were only found between control and MS with ON groups (p < 0.02). The ratio of the disease showed a significant correlation with fixation parameters in MS groups (p < 0.02), but not with AT. In MS patients, macular sensitivity is altered, especially in eyes with previous ON. Likewise, a fixational instability is present in MS patients with ON, with more increase of the V axis of the fixation area than of the H. The ratio of the disease also affects the patient fixation pattern.

Difficulties maintaining prolonged fixation and attention-deficit/hyperactivity symptoms share genetic influences in childhood

This study investigated the association between the ability to maintain prolonged (2-minute) fixation on a visual target and ADHD traits in a sample consisting of 120 monozygotic and 120 dizygotic twin pairs, aged 9 to 14 years. More intrusive saccades during the task was associated with higher level of parent-reported ADHD traits. Both intrusive saccades and ADHD symptoms had high heritability estimates, and there was a moderate genetic correlation between number of intrusive saccades and ADHD. This study suggests that inability to maintain ocular fixation for longer times is etiologically linked to ADHD traits in the general population.

Saccadic Eye Movements Attenuate Postural Sway but Less in Sleep-Deprived Young Adults.

Sleep deprivation affects the performance of postural control and several other aspects related to attentional mechanisms that may alter sensory cue acquisition strategies. This study aimed to examine the possible effects of horizontal saccades and ocular fixation on a target in the performance of postural control in young adults with sleep deprivation. Twenty-six adults formed two groups, tested in two evaluations. In the first evaluation, participants slept normally on the night before. In the second evaluation, 13 participants were sleep deprived (SD) and 13 slept normally (control group [CG]) on the night before. In both evaluations, each participant stood upright as still as possible, in two experimental conditions: fixating the eye on a target and performing saccadic movement toward a target presented in two different locations (0.5 Hz). Each participant performed 3 trials in each condition, lasting 62 s each. Body oscillation was obtained in both anterior–posterior and medial–lateral directions. Results showed that SD participants swayed with a larger magnitude and higher velocity after sleep deprivation in the fixation condition. In the saccadic condition, body sway magnitude and velocity were reduced but were still larger/higher in the SD participants. Sleep deprivation deteriorates the performance of postural control. Saccadic eye movements improve postural control performance even in sleep-deprived participants but are still not sufficient to avoid postural control deterioration due to sleep deprivation.

Measurement of Carotenoids in Perifovea using the Macular Pigment Reflectometer.

The macular pigment reflectometer (MPR) objectively measures the overall macular pigment optical density (MPOD) and further provides the lutein optical density (L-OD) and zeaxanthin optical density (Z-OD) in the central 1 degree of the fovea. A modification of the technique was developed to evaluate in vivo carotenoid density eccentric to the fovea. An adjustable track system with red LED lights was placed 6.1 m away from the participant to facilitate ocular fixation. Lights were spaced appropriately to create increments of 1 degree retinal disparity during the reflectometry measurements. All reflectometry measurements were obtained with pupillary dilation. The mean MPR-MPOD value for the central measurement was 0.593 (SD 0.161) with an L-OD to Z-OD ratio of 1:2.61. The MPR-MPOD value at 1 degree was 0.248 and the mean MPR-MPOD value at 2 degrees in the parafoveal region was 0.143. The L-OD to Z-OD ratio at 1 degree and 2 degrees off center was 1.38:1.0 and 2.08:1.0, respectively. The results demonstrate that MPOD measurements obtained using the MPR decrease as a function of retinal eccentricity and that there is a higher concentration of zeaxanthin centrally compared to lutein. The L-OD to Z-OD ratio changes with foveal eccentricity, with twice more lutein than zeaxanthin at 2 degrees off center. Our technique successfully provides a quick in vivo method for the measurement of macular pigment optical density at various foveal eccentricities. The results agree with prior published in vivo and in vitro xanthophyll carotenoid density distribution measurements.

Visual Fixation in NBA Free-Throws and the Relationship to On-Court Performance

Purpose&#x0D; Although hitting a baseball is often described as the most difficult task in all of sports, shooting baskets during a game likely ranks a close second. Previous studies have described the role of vision in basketball and more specifically a concept termed the “quiet eye” has been shown to be related to basketball performance. How a shooter visualizes the target, how consistent their visual fixation is, and how long they maintain that fixation has been correlated to shooting success. Although the majority of previous reports have included non-professional basketball shooters, we evaluated NBA (National Basketball Association) players to determine if this skill was significant at the professional level.&#x0D; Materials and Methods&#x0D; We evaluated 16 professional NBA players prior to the 2018-2019 NBA season. All players shot 30 consecutive free-throws while wearing Tobii Pro eye-tracking glasses. Following the completion of the task, several metrics were calculated including shooting success rate, as well as four measures of the position and duration of ocular fixation just prior to, during, and immediately after ball release for each shot of each player. Additionally, player performance statistics from the 2018-2019 season were recorded and compared to the visual fixation data. Descriptive statistics as well as correlations between the visual fixation metrics and on-court performance metrics were calculated.&#x0D; Results&#x0D; NBA shooters averaged a 79% success rate in free throw shooting (SD = 14%, min = 56%, max=100%) during the study. Moderate statistically significant correlations were found between the percentage of successful free throws and the four measures of visual fixation (r=0.539 to 0.687). In addition, visual fixation measures were found to be corelated with on-court metrics suggesting that shooters who had more frequent, as well as longer, fixations on the rim where more likely to have lower USG%, and ORB% as well as higher FG3%. The percentage of successful shots in the study was compared to the on-court FT% and found to be moderately correlated (r=0.536).&#x0D; Conclusions&#x0D; The need to maintain ocular fixation on the rim as one shoots seems elementary, but in fact varies greatly among NBA players, as noted in these results. Our data suggests that players who visually fixate longer and more frequently on the rim are more likely to be successful in free throws, as well as more successful in 3-point goals. Likely due to their likely distance from the basket, they do not make as many offensive rebounds. This data set appears to describe basketball guards in contrast to forwards/centers and supports previous research on non-professional basketball players.

Vestibular function in severe GH deficiency due to an inactivating mutation in the GH-releasing hormone receptor gene.

Body balance involves the vestibular, visual, and proprioceptive systems. IGF-I is a GH-dependent key factor in the development and postnatal differentiation of the inner ear in mice and men, but its role in the vestibular function in adult humans is unknown. We have previously described a cohort of individuals with severe isolated GH deficiency (IGHD) caused by a mutation in the GHRH receptor (GHRHR) gene. These individuals complain of dizziness, exhibit mild sensorineural loss, but have normal postural balance, without increase in falls risk. The aim of this study was to evaluate their vestibular function. We performed physical examination (clinical head impulse and Fukuda dynamic stepping test), oculomotor (saccadic eye movements, spontaneous, semi-spontaneous and opotokinetic nystagmus, and pendular tracking) and caloric stimulation (postcaloric reflex and ocular fixation index) tests, in 15 GH-naïve IGHD (seven males) and 15 controls (five males). IGHD subjects showed lower height and weight, with similar BMI to controls, and higher number of individuals with abnormal clinical head impulse test and abnormal oculomotor tests, namely the saccadic movements and the spontaneous nystagmus. There was a nonsignificant trend in abnormalities in the Fukuda stepping test and postcaloric reflex test. Adult untreated IGHD individuals have higher prevalence of moderate peripheral vestibular impairment, and of abnormal vestibular-ocular reflex.

Perioperative vestibular assessment and testing

Vestibular disorders can be difficult to accurately diagnose and manage. A careful history and focused physical examination are typically adequate to establish a diagnosis and initiate medical treatment. Vestibular testing is an important component of the work-up, but it is particularly essential for patients being considered for surgical intervention for a vestibular disorder, where the testing can be used to more definitively confirm a suspected diagnosis and to determine baseline vestibular organ function. In this article, we will first briefly review key components of the history and physical examination of patients with vestibular complaints. We will then discuss the most commonly used vestibular tests and their role in the preoperative assessment of patients undergoing vestibular surgery, including nystagmography, caloric testing, rotary chair testing, video head impulse testing, and vestibular evoked myogenic potential testing.

Impact of Working Experience on Image Perception and Image Evaluation Approaches in Stroke Imaging: Results of an Eye-Tracking Study.

Higher rates of missed pathologies, caused by a lack of professional experience or systematic search, suggest that a methodical approach to radiological analysis can be learned. Thus, the aim of this study is to investigate the efficiency of different principles of screening stroke CTs for cerebrovascular diseases between radiologists and neuroradiologists with different levels of experience in relation to professional experience. A set of anonymous CT images of 20 patients, with a suspected stroke, was individually presented to 12 radiologists with different levels of professional experience. Meanwhile, their fixation position was recorded by an eye-tracking system. For statistical analysis, the interobserver variability and accuracy of lesion detection were evaluated, taking the individual level of professional experience into account. The sensitivity of the observer depends on the professional experience, also determined by a systematic observation sequence and knowledge of the course of the disease. The duration of eye fixation with inexperienced assessors was significantly longer for conspicuous findings, while experienced assessors were more likely to fix clinically relevant regions. The retention time of ocular fixation in important pathological findings did not differ significantly between those groups. Our results indicate that experienced radiologists are reducing the number of missed findings through a systematic approach and targeted inspection of important regions. Through raising the awareness of analyzing CT images in systematic patterns, physicians at all levels of experience seem to be able to improve their performance. · Experienced radiologists improve detection rates through targeted inspection of clinically important regions.. · Experienced radiologists reduce time spent on analysis through focused visual attention.. · All levels of experience improve their performance by analyzing CT images systematically.. · Kammerer S, Schülke C, Leclaire MD et al. Impact of Working Experience on Image Perception and Image Evaluation Approaches in Stroke Imaging: Results of an Eye-Tracking Study. Fortschr Röntgenstr 2019; 191: 836 - 844.

Relationship between perceived self-reported trust in health information sources and ocular fixation in a sample of young adults: a secondary data analysis

Individuals use Internet for health-related issues to gather information and to share experiences and emotional support with other people who have similar medical problems. The easy access to information has sparked heated debate whether this converse urge to seek medical and health advice online is within the benefit of patients. In this research we set out to explore the relationship between self-perceived trust and visual interaction with medical websites, using eye tracking (ET) methods. The individual ocular reaction at 30-second exposure intervals to 20 health-related webpages was studied in 28 gender-balanced young adults by a Pro T60XL monitor device. The results showed a borderline strong statistically significant positive correlation (r=0.68, p=0.001) between logo fixations (LAOI) and self-reported trust rank. Websites that were ranked higher in terms of trust appear to be more likely to have a higher number of fixations on the logo. A moderate statistically significant positive correlation (r=0.526, p=0.017) was observed between fixations before the logo (FBL) and self-reported trust rank. Logos are a main point of ocular focus and are associated with higher trust. ET proves to be a useful assessment tool of behavioral patterns in searching online information.

The visual perception and attractiveness of maxillary central incisor abrasion as evaluated via eye-tracking

Abstract Aims: The aim of this study was to evaluate the visual esthetic perceptions of dentistry students and laypeople with regard to abrasions of the maxillary incisor edges in a frontal smile analysis. Materials and Methods: Abrasions were analyzed through a series of edited frontal photographs, at increments of 0.25, 0.5, 0.75, 1.0, and 1.5 mm, in two subjects (one male and one female, respectively). Raters were dentistry students and laypeople. To obtain ocular tracing data, two software programs Ogama and The Eye Tribe Tracker® were used together, which allowed us to visualize ocular movement in certain areas of interest. Specifically, the images were visualized by 30 dentistry students and 30 laypeople. Heat maps and scan paths were generated by the software programs to assess the main regions of ocular fixation. Results: According to the analyzed images, the larger the area of abrasion, the greater the visualization at that point. Small differences were observed in both groups; however, the students showed a higher concentration of attention in the region of abrasions as compared with the laypeople. Conclusions: There were differences between the groups. Dentistry students maintained their focus for most of the time in the region or near the region of abrasions, while laypeople largely diverged their gaze to other areas and allocated significant visual attention when they observed larger abrasions.

Spatial remapping in visual search: Remapping cues are provided at attended and ignored locations

We experience the world as stable and continuous, despite the fact that visual input is overwritten on the retina with each new ocular fixation. Spatial remapping is the process that integrates selected visual information into successive (continuous) representations of our spatial environment, thereby allowing us to keep track of objects, and experience the world as stable, despite frequent eye (re-)fixations. The present paper investigates spatial remapping in the context of visual pop-out search. Within standard instances of the pop-out paradigm, reactions to stimuli at previously attended locations are facilitated (faster and more accurate), and reactions to stimuli at previously ignored locations are inhibited (slower and less accurate). The mechanisms that support facilitation at previously attended locations, and inhibition at previously ignored locations, serve to enhance the efficiency of visual search. It is thus natural to expect that information about which locations were previously attended to or ignored is stored and remapped as a concomitant to successive representations of the spatial environment. Using variants of the pop-out paradigm, we corroborate this expectation, and show that information concerning the prior status of locations, as attended to or ignored, is remapped following attention shifts, with some degradation of information concerning ignored locations.

Unsupervised detection of microsaccades in a high-noise regime.

Micromovements of the eye during visual fixations provide clues about how our visual system acquires information. The analysis of fixational eye movements can thus serve as a noninvasive means to detect age-related or pathological changes in visual processing, which can in turn reflect associated cognitive or neurological disorders. However, the utility of such diagnostic approaches relies on the quality and usability of detection methods applied for the eye movement analysis. Here, we propose a novel method for (micro)saccade detection that is resistant to high-frequency recording noise, a frequent problem in video-based eye tracking in either aged subjects or subjects suffering from a vision-related pathology. The method is fast, it does not require manual noise removal, and it can work with position, velocity, or acceleration features, or a combination thereof. The detection accuracy of the proposed method is assessed on a new dataset of manually labeled recordings acquired from 14 subjects of advanced age (69-81 years old), performing an ocular fixation task. It is demonstrated that the detection accuracy of the new method compares favorably to that of two frequently used reference methods and that it is comparable to the best of the two algorithms when tested on an existing low-noise eye-tracking dataset.

Rehabilitation of Visual Loss: Where We Are and Where We Need to Be.

Spontaneous recovery of visual loss resulting from injury to the brain is variable. A variety of traditional rehabilitative strategies, including the use of prisms or compensatory saccadic eye movements, have been used successfully to improve visual function and quality-of-life for patients with homonymous hemianopia. More recently, repetitive visual stimulation of the blind area has been reported to be of benefit in expanding the field of vision. We performed a literature review with main focus on clinical studies spanning from 1963 to 2016, including 52 peer-reviewed articles, relevant cross-referenced citations, editorials, and reviews. Repetitive visual stimulation is reported to expand the visual field, although the interpretation of results is confounded by a variety of methodological factors and conflicting outcomes from different research groups. Many studies used subjective assessments of vision and did not include a sufficient number of subjects or controls. The available clinical evidence does not strongly support claims of visual restoration using repetitive visual stimulation beyond the time that spontaneous visual recovery might occur. This lack of firm supportive evidence does not preclude the potential of real benefit demonstrated in laboratories. Additional well-designed clinical studies with adequate controls and methods to record ocular fixation are needed.

A Subconscious Interaction between Fixation and Anticipatory Pursuit.

Ocular smooth pursuit and fixation are typically viewed as separate systems, yet there is evidence that the brainstem fixation system inhibits pursuit. Here we present behavioral evidence that the fixation system modulates pursuit behavior outside of conscious awareness. Human observers (male and female) either pursued a small spot that translated across a screen, or fixated it as it remained stationary. As shown previously, pursuit trials potentiated the oculomotor system, producing anticipatory eye velocity on the next trial before the target moved that mimicked the stimulus-driven velocity. Randomly interleaving fixation trials reduced anticipatory pursuit, suggesting that a potentiated fixation system interacted with pursuit to suppress eye velocity in upcoming pursuit trials. The reduction was not due to passive decay of the potentiated pursuit signal because interleaving "blank" trials in which no target appeared did not reduce anticipatory pursuit. Interspersed short fixation trials reduced anticipation on long pursuit trials, suggesting that fixation potentiation was stronger than pursuit potentiation. Furthermore, adding more pursuit trials to a block did not restore anticipatory pursuit, suggesting that fixation potentiation was not overridden by certainty of an imminent pursuit trial but rather was immune to conscious intervention. To directly test whether cognition can override fixation suppression, we alternated pursuit and fixation trials to perfectly specify trial identity. Still, anticipatory pursuit did not rise above that observed with an equal number of random fixation trials. The results suggest that potentiated fixation circuitry interacts with pursuit circuitry at a subconscious level to inhibit pursuit.SIGNIFICANCE STATEMENT When an object moves, we view it with smooth pursuit eye movements. When an object is stationary, we view it with fixational eye movements. Pursuit and fixation are historically regarded as controlled by different neural circuitry, and alternating between invoking them is thought to be guided by a conscious decision. However, our results show that pursuit is actively suppressed by prior fixation of a stationary object. This suppression is involuntary, and cannot be avoided even if observers are certain that the object will move. The results suggest that the neural fixation circuitry is potentiated by engaging stationary objects, and interacts with pursuit outside of conscious awareness.

Effect of aging on ocular fixation and microsaccades during optic flow

Effect of aging on ocular fixation and microsaccades during optic flow

Estimation of overlapped Eye Fixation Related Potentials: The General Linear Model, a more flexible framework than the ADJAR algorithm.

The Eye Fixation Related Potential (EFRP) estimation is the average of EEG signals across epochs at ocular fixation onset. Its main limitation is the overlapping issue. Inter Fixation Intervals (IFI) - typically around 300 ms in the case of unrestricted eye movement- depend on participants’ oculomotor patterns, and can be shorter than the latency of the components of the evoked potential. If the duration of an epoch is longer than the IFI value, more than one fixation can occur, and some overlapping between adjacent neural responses ensues. The classical average does not take into account either the presence of several fixations during an epoch or overlapping. The Adjacent Response algorithm (ADJAR), which is popular for event-related potential estimation, was compared to the General Linear Model (GLM) on a real dataset from a conjoint EEG and eye-tracking experiment to address the overlapping issue. The results showed that the ADJAR algorithm was based on assumptions that were too restrictive for EFRP estimation. The General Linear Model appeared to be more robust and efficient. Different configurations of this model were compared to estimate the potential elicited at image onset, as well as EFRP at the beginning of exploration. These configurations took into account the overlap between the event-related potential at stimulus presentation and the following EFRP, and the distinction between the potential elicited by the first fixation onset and subsequent ones. The choice of the General Linear Model configuration was a tradeoff between assumptions about expected behavior and the quality of the EFRP estimation: the number of different potentials estimated by a given model must be controlled to avoid erroneous estimations with large variances.