Attentional suppression of dynamic versus static salient distractors.

Attention must be carefully controlled to avoid distraction by salient stimuli. The signal suppression hypothesis proposes that salient stimuli can be proactively suppressed to prevent distraction. Although this hypothesis has garnered much support, most previous studies have used one class of salient distractors: color singletons. It therefore remains unclear whether other kinds of salient distractors can also be suppressed. The current study directly compared suppression of a variety of salient stimuli using an attentional capture task that was adapted for eye tracking. The working hypothesis was that static salient stimuli (e.g., color singletons) would be easier to suppress than dynamic salient stimuli (e.g., motion singletons). The results showed that participants could ignore a wide variety of salient distractors. Importantly, suppression was weaker and slower to develop for dynamic salient stimuli than static salient stimuli. A final experiment revealed that adding a static salient feature to a dynamic motion distractor greatly improved suppression. Altogether, the results suggest that an underlying inhibitory process is applied to all kinds of salient distractors, but that suppression is more readily applied to static features than dynamic features.

Artificial Intelligence in Eye Movements Analysis for Alzheimer's Disease Early Diagnosis.

As the world's population ages, Alzheimer's disease is currently the seventh most common cause of death globally; the burden is anticipated to increase, especially among middle-class and elderly persons. Artificial intelligence-based algorithms that work well in hospital environments can be used to identify Alzheimer's disease. A number of databases were searched for English-language articles published up until March 1, 2024, that examined the relationships between artificial intelligence techniques, eye movements, and Alzheimer's disease. A novel non-invasive method called eye movement analysis may be able to reflect cognitive processes and identify anomalies in Alzheimer's disease. Artificial intelligence, particularly deep learning, and machine learning, is required to enhance Alzheimer's disease detection using eye movement data. One sort of deep learning technique that shows promise is convolutional neural networks, which need further data for precise classification. Nonetheless, machine learning models showed a high degree of accuracy in this context. Artificial intelligence-driven eye movement analysis holds promise for enhancing clinical evaluations, enabling tailored treatment, and fostering the development of early and precise Alzheimer's disease diagnosis. A combination of artificial intelligence-based systems and eye movement analysis can provide a window for early and non-invasive diagnosis of Alzheimer's disease. Despite ongoing difficulties with early Alzheimer's disease detection, this presents a novel strategy that may have consequences for clinical evaluations and customized medication to improve early and accurate diagnosis.

Sense of agency at a gaze-contingent display with jittery temporal delay.

Introduction: Inconsistent jittery temporal delays between action and subsequent feedback, prevalent in network-based human-computer interaction (HCI), have been insufficiently explored, particularly regarding their impact on the sense of agency (SoA). This study investigates the SoA in the context of eye-gaze HCI under jittery delay conditions. Methods: Participants performed a visual search for Chinese characters using a biresolutional gaze-contingent display, which displayed a high-resolution image in the central vision and a low-resolution in the periphery. We manipulated the delay between eye movements and display updates using a truncated normal distribution (µ to µ + 2 σ) with µ ranging from 0 to 400 ms and σ fixed at 50 ms. Playback of recorded gaze data provided a non-controllable condition. Results: The study revealed that both reported authorship and controllability scores, as well as the fixation count per second, decreased as µ increased, aligning with trends observed under constant delay conditions. The subjective authorship weakened significantly at a µ of 94 ms. Notably, the comparison between jittery and constant delays indicated the minimum value (µ) of the distribution as a critical parameter influencing both authorship perception and visual search time efficiency. Discussion: This finding underscores the importance of the shortest delay in modulating SoA. Further examining the relative distribution for fixation duration and saccade amplitude suggests an adaptation in action planning and attention distribution in response to delay. By providing a systematic examination of the statistical attributes of jittery delays that most significantly affect SoA, this research offers valuable implications for the design of efficient, delay-tolerant eye-gaze HCI, expanding our understanding of SoA in technologically mediated interactions. Moreover, our findings highlight the significance of considering both constant and variable delay impacts in HCI usability design, marking a novel contribution to the field.

Ocular working memory signals are flexible to behavioral priority and subjective imagery strength.

The pupillary light response was long considered a brainstem reflex, outside of cognitive influence. However, newer findings indicate pupil dilation (and eye movements) can reflect content in working memory (WM). These findings may reshape understanding of ocular and WM mechanisms, but it is unclear whether the signals are artifactual or functional to WM. Here, we ask whether peripheral and oculomotor WM signals are sensitive to the task-relevance or 'attentional state' of memoranda. During eye-tracking, human participants saw both dark and bright WM stimuli, then were retroactively cued to the most likely to be tested item. Critically, we manipulated the attentional priority among items by varying the cue reliability across blocks. We confirmed previous findings that remembering darker items is associated with larger pupils, and that gaze is biased toward cued item locations. Moreover, we discovered that pupil and eye movement responses were influenced differently by WM item relevance. Feature-specific pupillary effects emerged only for highly prioritized WM items but were eliminated when cues were less reliable, and pupil effects also increased with self-reported visual imagery strength. Conversely, gaze position veered toward the cued item location, regardless of cue reliability. However, biased microsaccades occurred at a higher frequency when cues were reliable, though only during a limited post-cue time window. Therefore, peripheral sensorimotor processing is sensitive to the task-relevance or functional state of internal WM content, but pupillary and eye movement WM signals show distinct profiles. These results highlight potential roles for early visual processing in maintaining multiple WM content dimensions.

Sustained bias of spatial attention in a 3 T MRI scanner.

When lying inside a MRI scanner and even in the absence of any motion, the static magnetic field of MRI scanners induces a magneto-hydrodynamic stimulation of subjects' vestibular organ (MVS). MVS thereby not only causes a horizontal vestibular nystagmus but also induces a horizontal bias in spatial attention. In this study, we aimed to determine the time course of MVS-induced biases in both VOR and spatial attention inside a 3 T MRI-scanner as well as their respective aftereffects after participants left the scanner. Eye movements and overt spatial attention in a visual search task were assessed in healthy volunteers before, during, and after a one-hour MVS period. All participants exhibited a VOR inside the scanner, which declined over time but never vanished completely. Importantly, there was also an MVS-induced horizontal bias in spatial attention and exploration, which persisted throughout the entire hour within the scanner. Upon exiting the scanner, we observed aftereffects in the opposite direction manifested in both the VOR and in spatial attention, which were statistically no longer detectable after 7 min. Sustained MVS effects on spatial attention have important implications for the design and interpretation of fMRI-studies and for the development of therapeutic interventions counteracting spatial neglect.

Dorsal pulvinar inactivation leads to spatial selection bias without perceptual deficit.

The dorsal pulvinar has been implicated in visuospatial attentional and perceptual confidence processing. Pulvinar lesions in humans and monkeys lead to spatial neglect symptoms, including an overt spatial saccade bias during free choices. However, it remains unclear whether disrupting the dorsal pulvinar during target selection that relies on a perceptual decision leads to a perceptual impairment or a more general spatial orienting and choice deficit. To address this question, we reversibly inactivated the unilateral dorsal pulvinar by injecting GABA-A agonist THIP while two macaque monkeys performed a color discrimination saccade task with varying perceptual difficulty. We used Signal Detection Theory and simulations to dissociate perceptual sensitivity (d-prime) and spatial selection bias (response criterion) effects. We expected a decrease in d-prime if dorsal pulvinar affects perceptual discrimination and a shift in response criterion if dorsal pulvinar is mainly involved in spatial orienting. After the inactivation, we observed response criterion shifts away from contralesional stimuli, especially when two competing stimuli in opposite hemifields were present. Notably, the d-prime and overall accuracy remained largely unaffected. Our results underline the critical contribution of the dorsal pulvinar to spatial orienting and action selection while showing it to be less important for visual perceptual discrimination.

Sleep disturbances and incident risk of major depressive disorder in a population-based cohort.

Sleep disturbances are well-known symptoms of major depressive disorder (MDD). However, the prospective risk of MDD in the presence of sleep disturbances in a general population-based cohort is not well known. This study investigated associations between both polysomnography (PSG)-based or subjective sleep features and incident MDD. Participants representative of the general population who had never had MDD completed sleep questionnaires (n = 2000) and/or underwent PSG (n = 717). Over 8 years' follow-up, participants completed psychiatric interviews enabling the diagnosis of MDD. Survival Cox models were used to analyze associations between sleep features and MDD incidence. A higher Epworth Sleepiness Scale and presence of insomnia symptoms were significantly associated with a higher incidence of MDD (hazard ratio [HR] [95 % confidence interval (CI)]: 1.062 [1.022-1.103], p = 0.002 and 1.437 [1.064-1.940], p = 0.018, respectively). Higher density of rapid eye movements in rapid eye movement (REM) sleep was associated with a higher incidence of MDD in men (HR 1.270 [95 % CI 1.064-1.516], p = 0.008). In women, higher delta power spectral density was associated with a lower MDD incidence (HR 0.674 [95 % CI 0.463-0.981], p = 0.039). This study confirmed the associations between subjective and objective sleep features and the incidence of MDD in a large community dwelling cohort.

Effect of methylphenidate on oculomotor function in individuals with multiple sclerosis: a pilot randomized placebo-controlled trial.

Introduction: Individuals with multiple sclerosis (MS) frequently experience visual and oculomotor symptoms that may impact and confound neuropsychological assessments of information processing speed (IPS). In this study, we examined the effect of the psychostimulant methylphenidate on oculomotor function and the association between change in oculomotor speed and change in information processing speed. Methods: We used a repeated measures crossover design in which a sample of 11 participants with MS were randomly assigned to one of two treatment arms: one that received methylphenidate for 4 weeks and another that received a placebo for 4 weeks. After a 7-day washout period, the treatments were crossed over. The King Devick test, the Symbol Digit Modalities Test, and the Paced Auditory Serial Addition Test were administered at baseline and after each of the two study arms. Results: We found a significant improvement in oculomotor speed in the methylphenidate condition as compared to placebo. This improvement was significantly correlated with improvement on a visuomotor assessment of IPS (Symbol Digit Modalities Test), but no such association was found for an auditory-verbal assessment of IPS (Paced Auditory Serial Addition Test). Discussion: These findings suggest that individuals with MS experience improved oculomotor speed while taking methylphenidate, which may, in turn, improve performance on assessments of IPS with visuomotor demands.

Just-in-Time Encoding Into Visual Working Memory Is Contingent Upon Constant Availability of External Information.

Humans maintain an intricate balance between storing information in visual working memory (VWM) and just-in-time sampling of the external world, rooted in a trade-off between the cost of maintaining items in VWM versus retrieving information as it is needed. Previous studies have consistently shown that one prerequisite of just-in-time sampling is a high degree of availability of external information, and that introducing a delay before being able to access information led participants to rely less on the external world and more on VWM. However, these studies manipulated availability in such a manner that the cost of sampling was stable and predictable. It is yet unclear whether participants become less reliant on external information when it is more difficult to factor in the cost of sampling that information. In two experiments, participants copied an example layout from the left to the right side of the screen. In Experiment 1, intermittent occlusion of the example layout led participants to attempt to encode more items per inspection than when the layout was constantly available, but this did not consistently result in more correct placements. However, these findings could potentially be explained by inherent differences in how long the example layout could be viewed. Therefore in Experiment 2, the example layout only became available after a gaze-contingent delay, which could be constant or variable. Here, the introduction of any delay led to increased VWM load compared to no delay, although the degree of variability in the delay did not alter behaviour. These results reaffirm that the nature of when we engage VWM is dynamical, and suggest that any disruption to the continuous availability of external information is the main driver of increased VWM usage relative to whether availability is predictable or not.

Lateral rectus pulley concerning the orbital wall. Area of a stereotyped bony insertion.

Purpose: To examine the lateral rectus muscle pulley and its bony insertion concerning the orbital rim and periorbita. Design: Prospective. An observational anatomic study. Methods: Study population: Twenty postmortem orbits (10 right, 10 left) of 10 Caucasian cadavers (8 females, 2 males; age range at death, 57-100 years; median age, 79.5 years) fixed by the Thiel method.Intervention: The floor of the temporal fossa was exposed, and a bone window on the lateral wall of the orbit, posterior to the sphenozygomatic suture, was created, keeping the periorbita intact. The lateral canthus and lateral palpebral ligament were isolated and opened, and the eyelids were folded back. The frontozygomatic suture was identified, and the orbital septum opened adjacent to the orbital rim. The conjunctiva was opened at the limbus, and the lateral rectus insertion was isolated. The bone pillar containing the frontozygomatic suture and the insertion of the periorbita and the pulley was isolated and removed en bloc. The lateral rectus muscle was isolated and excised.Main outcome measures: Position of the pulley ring on the lateral rectus muscle belly and its bony attachment area in the lateral wall of the orbit. Results: The pulley bony attachment was roughly quadrilateral with an approximate area of 90 mm2, 3 mm (mean, range 1-5 mm) posteroinferior to the frontozygomatic suture and 1 mm posterior to the orbital rim. The anterior margin of the pulley sleeve was found at 21.0 mm (median, p25-75 20.0-22.8) from the scleral insertion. Conclusions: The lateral rectus pulley is stereotyped in its position in the muscle belly and its bony insertion, coinciding with the point of greatest adhesion of the periorbita to the anterior part of the lateral wall of the orbit.

Infants' reorienting efficiency depends on parental autistic traits and predicts future socio-communicative behaviors.

Attentional reorienting is dysfunctional not only in children with autism spectrum disorder (ASD), but also in infants who will develop ASD, thus constituting a potential causal factor of future social interaction and communication abilities. Following the research domain criteria framework, we hypothesized that the presence of subclinical autistic traits in parents should lead to atypical infants' attentional reorienting, which in turn should impact on their future socio-communication behavior in toddlerhood. During an attentional cueing task, we measured the saccadic latencies in a large sample (total enrolled n = 89; final sample n = 71) of 8-month-old infants from the general population as a proxy for their stimulus-driven attention. Infants were grouped in a high parental traits (HPT; n = 23) or in a low parental traits (LPT; n = 48) group, according to the degree of autistic traits self-reported by their parents. Infants (n = 33) were then longitudinally followed to test their socio-communicative behaviors at 21 months. Results show a sluggish reorienting system, which was a longitudinal predictor of future socio-communicative skills at 21 months. Our combined transgenerational and longitudinal findings suggest that the early functionality of the stimulus-driven attentional network-redirecting attention from one event to another-could be directly connected to future social and communication development.

A pupillary contrast response in mice and humans: Neural mechanisms and visual functions.

In the pupillary light response (PLR), increases in ambient light constrict the pupil to dampen increases in retinal illuminance. Here, we report that the pupillary reflex arc implements a second input-output transformation; it senses temporal contrast to enhance spatial contrast in the retinal image and increase visual acuity. The pupillary contrast response (PCoR) is driven by rod photoreceptors via type 6 bipolar cells and M1 ganglion cells. Temporal contrast is transformed into sustained pupil constriction by the M1's conversion of excitatory input into spike output. Computational modeling explains how the PCoR shapes retinal images. Pupil constriction improves acuity in gaze stabilization and predation in mice. Humans exhibit a PCoR with similar tuning properties to mice, which interacts with eye movements to optimize the statistics of the visual input for retinal encoding. Thus, we uncover a conserved component of active vision, its cell-type-specific pathway, computational mechanisms, and optical and behavioral significance.

A behavioral advantage for the face pareidolia illusion in peripheral vision.

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.

Visual behavior of racing bike cyclists in multi-tasking situations.

Distracted biking can have serious repercussions for the rider such as accidents. The purpose of the present experiment was to determine the effect of visually monitoring two parameters, the cadence, and the heart rate on a bike computer fixed on a racing bike, and simultaneously detect hazardous traffic situations. Individuals (n = 20) were instructed to ride a racing bike that was fitted onto a roller trainer. After conducting a bicycle step test to assess the maximal heart rate (HFmax), participants were assigned to a within subject-design on a separate day. They were instructed to perform the riding task in two single-task conditions (only watching the traffic at the video with occluded or without occluded bike computer), two multi-tasking conditions (monitoring the cadence of 70 RPM or 90 RPM, monitoring the heart rate, and observing the traffic) and one control condition (no instructions). Percentage dwell time of the eye movements, the constant error from the target cadence, keeping the heart rate in an interval of 50% - 70% of the HFmax, and percentage of the recognized hazard traffic situations were analyzed. The analysis indicated that monitoring the parameters on the bike computer induced no significant decline in perceived hazardous traffic situations.

Relationship between retraction and refraction values in patients with Duane's retraction syndrome.

PURPOSE: To evaluate refractive findings in patients with unilateral Duane's retraction syndrome (DRS). METHODS: This retrospective study included 40 patients followed for unilateral DRS. Detailed ophthalmological examinations of the patients were performed. The spherical and cylindrical refractive error, spherical equivalent, and type of refractive error in the eyes with DRS and the fellow eyes were determined. The patients were divided into three subgroups according to their type of DRS. The refractive properties of the eyes with DRS were examined in subgroup analyses. Eye movement limitation was graded between +1 and +4 and compared according to the refractive error type. RESULTS: The mean age of the patients was 16.8±12.6 (range, 1-60) years. Of the eyes with DRS, 11 (27.5%) were emmetropic, four (10%) were hyperopic, two (5%) were myopic, 11 (27.5%) were myopic astigmatic, and 12 (30.0%) were hyperopic astigmatic. There was no statistically significant difference between the eyes with DRS and fellow eyes in relation to the spherical or cylindrical refractive errors or spherical equivalent (P>0.05 for all). The refraction values for the patients with type 1, type 2 and type 3 DRS were similar between groups (P>0.05). No statistically significant difference was detected in the degree of eye movement limitation according to refractive status (P>0.05). CONCLUSION: In patients with unilateral DRS, there was no significant difference between the affected eyes and the fellow eyes in terms of refractive error values or types. Refractive status did not significantly differ according to the degree of eye movement limitation. Therefore, although extraocular muscles are affected by DRS, there may not be any significant refractive changes.

Abnormal eye movements increase as motor disabilities and cognitive impairments become more evident in Multiple Sclerosis: A novel eye-tracking study.

Background: Eye movements can reflect brain alterations and inform on the presence of motor disabilities and cognitive impairments in people with multiple sclerosis (pwMS). Objective: The aim of the study was to determine the correlation between motor and cognitive measurements and eye movement parameters when performing the n-back task (NBKT). Methods: This was a cross-sectional study carried out at Ramos Mejía Hospital, a center specialized in demyelinating diseases in Buenos Aires, Argentina. The study population consisted of 66 patients with relapsing-remitting multiple sclerosis (RRMS) and 5 patients with secondary progressive multiple sclerosis (SPMS). pwMS performed the n-back test while using a device head mounted display (HMD) with eyetracking capabilities in order to capture eye movement. Clinical motor and cognitive measures were assessed with Expanded Disability Status Scale (EDSS), Nine Hole Peg Test (NHPT), Timed 25-Foot Walk (T25FW), and Symbol Digit Modalities Test (SDMT). Results: pwMS showed strong and statistically significant correlations between gaze duration; number of fixations, saccade amplitude and motor disabilities and cognitive impairments as measured by EDSS, NHPT, T25FW, and SDMT. Conclusion: This study found significant correlations between eye movement behavior and motor and cognitive disability in pwMS. These findings suggest that eye movements have the potential to be used as a surrogate biomarker in MS progression.

Reflexive and voluntary saccadic eye movements as biomarker of Huntington's Disease.

INTRODUCTION: Subtle abnormalities in the preclinical stage of Huntington's Disease (HD) can be detected using saccadic eye movement assessment reflecting disease progression. This study was aimed to evaluate abnormalities in saccade parameters in asymptomatic carriers and symptomatic HD patients at various stages of HD. MATERIAL AND METHODS: The study enrolled 104 participants, including 14 asymptomatic carriers of HTT mutations, 44 symptomatic HD patients, and 46 control subjects. HD severity was measured using the Unified Huntington's Disease Rating Scale Total Motor Score (UHDRS-TMS) and Total Functional Capacity Scale (TFC). The evaluation of rapid eye movements (reflexive saccades, anti-saccades, memory-guided saccades) was carried out using 'Saccadometer Research'. RESULTS: Measures of reflexive and volitional saccades did not differ between the asymptomatic carriers and controls. Significant latency prolongation and increased physiological variability of latency times, as well as higher error rates among HD patients, were found in all saccade tasks (p < 0.001) compared to the controls. Abnormalities in saccade parameters were more pronounced in the advanced stages of the disease. Latency of saccades and error rate of volitional saccades correlated with the UHDRS-TMS and TFC scores. CONCLUSIONS: The saccade parameters in asymptomatic HD carriers with a long time to disease development were similar to those in the control group. Saccade abnormalities appeared in symptomatic patients at the beginning of the disease, and correlated with HD severity.

The effects of restrictiveness on relative clause processing in Farsi.

With an eye-tracking experiment, we investigated the processing of Farsi object and subject relative clauses. Since restrictive relative clauses in Farsi are marked and distinguished clearly by the enclitic particle ی /-i/ attached to the head noun, we also compared the processing of restrictive and non-restrictive relative clauses. Seifi (2021) conducted a corpus analysis that showed that object relative clauses are in general less frequent than subject relative clauses. However, while non-restrictive relative clauses are predominantly subject relative clauses, restrictive relative clauses are more balanced in the corpus. In an eye-tracking experiment, Farsi speakers processed restrictive and non-restrictive relative clauses differently. In non-restrictive relative clauses, the effect is similar to that found in most other languages: a clear processing delay in object relative clauses, compared to subject relative clauses. This effect was visible both at the relative clause verb and at the end of the matrix sentence. In restrictive relative clauses, on the other hand, the picture is different: Just as for the non-restrictive relative clauses object relative clauses had long reading times in the relative clause, but at the end of the sentence a reverse effect was found. Thus, the processing data reflected the pattern found in the corpus. We discuss these findings in terms of the distinct functions of restrictive and non-restrictive relative clauses.

Parafoveal Processing of Orthography, Phonology, and Semantics during Chinese Reading: Effects of Foveal Load.

The foveal load hypothesis assumes that the ease (or difficulty) of processing the currently fixated word in a sentence can influence processing of the upcoming word(s), such that parafoveal preview is reduced when foveal load is high. Recent investigations using pseudo-character previews reported an absence of foveal load effects in Chinese reading. Substantial Chinese studies to date provide some evidence to show that parafoveal words may be processed orthographically, phonologically, or semantically. However, it has not yet been established whether parafoveal processing is equivalent in terms of the type of parafoveal information extracted (orthographic, phonological, semantic) under different foveal load conditions. Accordingly, the present study investigated this issue with two experiments. Participants' eye movements were recorded as they read sentences in which foveal load was manipulated by placing a low- or high-frequency word N preceding a critical word. The preview validity of the upcoming word N + 1 was manipulated in Experiment 1, and word N + 2 in Experiment 2. The parafoveal preview was either identical to word N + 1(or word N + 2); orthographically related; phonologically related; semantically related; or an unrelated pseudo-character. The results showed robust main effects of frequency and preview type on both N + 1 and N + 2. Crucially, however, interactions between foveal load and preview type were absent, indicating that foveal load does not modulate the types of parafoveal information processed during Chinese reading.

Temporal dynamics of ocular torsion and vertical vergence during visual, vestibular, and visuovestibular rotations.

Ocular torsion and vertical divergence reflect the brain's sensorimotor integration of motion through the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) to roll rotations. Torsion and vergence however express different response patterns depending on several motion variables, but research on their temporal dynamics remains limited. This study investigated the onset times of ocular torsion (OT) and vertical vergence (VV) during visual, vestibular, and visuovestibular motion, as well as their relative decay rates following prolonged optokinetic stimulations. Temporal characteristics were retrieved from three separate investigations where the level of visual clutter and acceleration were controlled. Video eye-tracking was used to retrieve the eye-movement parameters from a total of 41 healthy participants across all trials. Ocular torsion consistently initiated earlier than vertical vergence, particularly evident under intensified visual information density, and higher clutter levels were associated with more balanced decay rates. Additionally, stimulation modality and accelerations affected the onsets of both eye movements, with visuovestibular motion triggering earlier responses compared to vestibular motion, and increased accelerations leading to earlier onsets for both movements. The present study showed that joint visuovestibular responses produced more rapid onsets, indicating a synergetic sensorimotor process. It also showed that visual content acted as a fusional force during the decay period, and imposed greater influence over the torsional onset compared to vergence. Acceleration, by contrast, did not affect the temporal relationship between the two eye movements. Altogether, these findings provide insights into the sensorimotor integration of the vestibulo-ocular and optokinetic reflex arcs.