Purpose: When tested under monocular viewing conditions, humans and monkeys with infantile strabismus often show strong eye movement responses to nasally directed visual motion stimuli and weak responses to temporally directed stimuli. The goal of this study was to compare and contrast these naso-temporal asymmetries during three visually mediated eye movement responses - optokinetic nystagmus (OKN), smooth-pursuit (SP) and ocular following (OFR).. Methods: Two strabismic monkeys (1 esotrope (ET) and 1 exotrope (XT)) were tested under monocular viewing conditions during nasal or temporal OKN, SP or OFR stimulation. OKN stimulus was unidirectional motion of a 70°X50° random dot pattern at 20, 40 or 80 °/s for 1 minute. SP stimulus was foveal step-ramp target motion at 10, 20 or 40 °/s. OFR stimulus was brief (200ms) unidirectional motion of a 38°X29° random dot pattern at 20, 40 or 80 °/s. Data from both left and right eye viewing conditions were combined for statistical analysis of eye ...
Purpose: To determine whether the patterns of fixational eye movements are altered when images are defocused (low pass-filtered).. Methods: Six subjects (3 male, 3 female, 22 - 32 years of age, Caucasian origin) were asked to inspect an image on the computer screen which was either "in focus" or low-pass filtered by convolution with a point spread function that was equivalent to 5D of myopic defocus. The screen was at 79 cm distance and one pixel on the screen subtended a visual angle of 1.45 arcmin. The movements of the right eye were tracked at 166 Hz sampling rate in a highly magnified video image (39.9 pixels/mm) by custom-developed software (Visual C++ 8.0). A commercial IR camera (DMK 22AUC03, www.theimagingsource.com) was used and a single IR LED that generated a bright first Purkinje image. The angular resolution in natural eyes was determined to be 1-2 arcmin. Differences in eye movements variables were determined in the pooled data of all subjects using t-tests, analyzing the ...
Eye movement includes the voluntary or involuntary movement of the eyes, helping in acquiring, fixating and tracking visual stimuli. Specific systems are used in maintaining fixation, when reading and in music reading. A special type of eye movement, rapid eye movement, occurs during REM sleep. The eyes are the visual organs of the human body, and move using a system of six muscles. The retina, a specialised type of tissue containing photoreceptors, senses light. These specialised cells convert light into electrochemical signals. These signals travel along the optic nerve fibers to the brain, where they are interpreted as vision in the visual cortex. Primates and many other vertebrates use three types of voluntary eye movement to track objects of interest: smooth pursuit, vergence shifts and saccades. These movements appear to be initiated by a small cortical region in the brains frontal lobe. This is corroborated by removal of the frontal lobe. In this case, the reflexes (such as reflex ...
The present disclosure is intended to describe embodiments for improving image data acquisition and processing in accelerated dynamic magnetic resonance imaging sequences. One embodiment is described where a method includes an acquisition sequence configured to acquire an undersampled set of magnetic resonance data. The undersampled set of magnetic resonance data has a pseudo-random sampling pattern within a data space acquired at a first time, the pseudo-random sampling pattern being influenced by other pseudo-random sampling patterns within the data space arising from the acquisition of additional undersampled sets of magnetic resonance data at respective times. In some embodiments, the pseudo-random sampling patterns of the undersampled sets of magnetic resonance data interleave to yield a desired sampling pattern.
The present disclosure is intended to describe embodiments for improving image data acquisition and processing in accelerated dynamic magnetic resonance imaging sequences. One embodiment is described where a method includes an acquisition sequence configured to acquire an undersampled set of magnetic resonance data. The undersampled set of magnetic resonance data has a pseudo-random sampling pattern within a data space acquired at a first time, the pseudo-random sampling pattern being influenced by other pseudo-random sampling patterns within the data space arising from the acquisition of additional undersampled sets of magnetic resonance data at respective times. In some embodiments, the pseudo-random sampling patterns of the undersampled sets of magnetic resonance data interleave to yield a desired sampling pattern.
There was a lot of past effort to figure out what fixational eye movements contribute to our vision," adds lead author Ziad Hafed, Ph.D., Sloan-Swartz Fellow in the Systems Neurobiology Laboratory, "but nobody had looked at the neural mechanism that generates these movements. Without such knowledge, one could only go so far in evaluating microsaccades significance and why they actually exist." Wondering whether the command center responsible for generating fixational eye movements resides within the same brain structure that is in charge of initiating and directing large voluntary eye movements, Hafed decided to measure neural activity in the superior colliculus before and during microsaccades. He not only discovered that the superior colliculus is an integral part of the neural mechanism that controls microsaccades, but he also found that individual neurons in the superior colliculus are highly specific about which particular microsaccade directions and amplitudes they command-whether they be, ...
Neural data and models have proposed that the brain achieves invariant object recognition by learning and combining several views of a three-dimensional object. How such invariant codes are learned when active eye movements scan a scene, given that the cortical magnification introduces a large source of variability in the visual representation even for the same view of the object? How does the brain avoid the problem of erroneously classifying together parts of different objects when an eye movement changes the cortical representation from one to the other? How does the brain differentiate between saccades on the same object and saccades between different objects? A biologically inspired ARTSCAN model of visual object learning and recognition with active eye movements proposes answers to these questions. The model explains how surface attention interacts with eye movement generating modules and object recognition modules so that the views that correspond to the same object are selectively ...
Internal monitoring of oculomotor commands may help to anticipate and keep track of changes in perceptual input imposed by our eye movements. Neurophysiological studies in non-human primates identified corollary discharge signals of oculomotor commands that are conveyed via thalamus to frontal cortices. We tested whether disruption of these monitoring pathways on the thalamic level impairs the perceptual matching of visual input before and after an eye movement in human subjects. Fourteen patients with focal thalamic stroke and twenty healthy control subjects performed a task requiring a perceptual judgment across eye movements. Subjects reported the apparent displacement of a target cue that jumped unpredictably in sync with a saccadic eye movement. In a critical condition of this task, six patients exhibited clearly asymmetric perceptual performance for rightward versus leftward saccade direction. Furthermore, perceptual judgments in seven patients systematically depended on oculomotor targeting
The spatial alignment of gaze location between the measuring eye tracker and the responding display system is obviously crucial in gaze-contingent studies. However, a misalignment is almost inevitable during eye movements due to time delays between the eye tracker and the display equipment. This system latency includes the time for data transmission from the eye tracker to the display, the processing time for image manipulation, and the time for refreshing the display. The total delay varies based on the equipment and software, and reported values have ranged between 9 and 50 ms (Dorr & Bex, 2011; Saunders & Woods, in press; Schumacher, Allison, & Herpers, 2004; Triesch, Sullivan, Hayhoe, & Ballard, 2002; Yang, Wang, Tong, & Rayner, 2012). For fast saccadic eye movements, that time delay may cause a large misalignment. Take a 20° saccade as an example: the peak velocity can be 350°/s-450°/s (Enderle, Blanchard, & Bronzino, 2005), which may lead to 8° displacement on average within 20 ms. ...
Rapid eye movement in babies - My four month old baby son seems to have rapid eye movement at different times during the day. Is that normal. Its not very fast movement either. REM. Rapid eye movements may be entirely normal in infants HOWEVER THIS is the kind of observation your Pediatrician will NOT be annoyed about if you question him/her......suggest you check this out.... Hope this is helpful Dr Z
Child Development Research is a peer-reviewed, Open Access journal that publishes original research articles as well as review articles in all areas of child development research.
Purpose: To investigate whether glaucoma produces measurable changes in eye movements.. Methods: Fifteen glaucoma patients with asymmetric vision loss (difference in mean deviation [MD] , 6 dB between eyes) were asked to monocularly view 120 images of natural scenes, presented sequentially on a computer monitor. Each image was viewed twice-once each with the better and worse eye. Patients eye movements were recorded with an Eyelink 1000 eye-tracker. Eye-movement parameters were computed and compared within participants (better eye versus worse eye). These parameters included a novel measure: saccadic reversal rate (SRR), as well as more traditional metrics such as saccade amplitude, fixation counts, fixation duration, and spread of fixation locations (bivariate contour ellipse area [BCEA]). In addition, the associations of these parameters with clinical measures of vision were investigated.. Results: In the worse eye, saccade ...
Reading requires very accurate saccadics which are fixations from one spot to another. A second type of eye movement which involves tracking is, also, related to attention and reading. Children who have poor eye movements are easily distracted and loose their place. Remember, the eye movement system was designed so that peripheral vision detects motion and danger. Imagine what happens when the system works correctly in the class room. As soon as there is peripheral movement the eyes move towards the source of movement. This results in the complaint of inattention. Thus, reflexive eye movement skills must be socialized so that they do not respond reflexively to peripheral information. In addition, speed and accuracy must be trained so that one does not loose ones place.. The skills are easily improvable with vision therapy (See testimonial for patient comments). Once the information is brought into the eyes it must be sent back to the brain for appropriate processing. The information must be ...
This study examined performance measures and eye movements associated with complex arithmetic strategies in young and older adults. Participants added pairs of three-digit numbers using two different strategies, under choice and no-choice conditions. Older adults made more errors but were not significantly slower than young adults, and response times and errors showed no interaction between age and the number of carries. Older adults chose strategies less adaptively than young adults. Eye movements were consistent with use of required strategies on no-choice trials and reported strategies on choice trials. Eye movement data also suggested that young adults more successfully distinguished between strategies. Implications of these findings for understanding aging effects in complex arithmetic are discussed ...
p,Humans can distinguish visual stimuli that differ by features the size of only a few photoreceptors. This is possible despite the incessant image motion due to fixational eye movements, which can be many times larger than the features to be distinguished. To perform well, the brain must identify the retinal firing patterns induced by the stimulus while discounting similar patterns caused by spontaneous retinal activity. This is a challenge since the trajectory of the eye movements, and consequently, the stimulus position, are unknown. We derive a decision rule for using retinal spike trains to discriminate between two stimuli, given that their retinal image moves with an unknown random walk trajectory. This algorithm dynamically estimates the probability of the stimulus at different retinal locations, and uses this to modulate the influence of retinal spikes acquired later. Applied to a simple orientation-discrimination task, the algorithm performance is consistent with human acuity, whereas ...
Kawaii, a positive adjective that denotes such positive connotations as cute, lovable, and charming, becomes more important as one kansei value. It plays an important role in the success of many products. Based on this success, we believe that kawaii will be a key factor for future product design. In one of our previous study, we experimentally evaluated kawaii illustrations using eye tracking device. The result clarified relationship between kawaii feelings and eye movement indexes. In our other study, we experimentally evaluated kawaiiness of spoon designs. However, we have not employed the eye tracking in the study yet. Then, in this study, we evaluated the kawaiiness of spoon designs using eye tracking. The participant compared and selected more kawaii spoon designs from the pairs on the display, and eye movements had been recording meanwhile. Finally, we obtained the suggestion for the relationship between kawaii feelings and eye movement indexes for spoon designs ...
A pair of Beckman Institute researchers has discovered that by directing the eye movements of test subjects they were able to affect the participants ability to solve a problem, demonstrating that eye movement is not just a function of cognition but can actually affect our cognitive processes.
This paper introduces an approach to use eye movement data in the context of program comprehension studies. The central aspect is the development of coding schemes, which reflect cognitive processes behind the observable visual behavior of programmers. For this purpose, we discuss to first use a quantitative approach to find those episodes in the eye movements that yield the most potential for analysis. Subsequently, qualitative methods can be used on this subset.. ...
Apparatus for recording eye movement. A light source has its rays directed toward the eye of a subject and a glass dome secured to spectacle frames worn by the subject. The primary and secondary glints reflected off the glass dome and eye cornea, respectively, are transmitted via mirrors, lenses and a fiber optic image guide to a video camera tube. The position of the glints on an XY axis is electronically determined and the information is fed to a computer which compares the data from the two glints and compensates for the head movement which corresponds to movement of the primary glint.
Extraocular eye movement is a function of cranial nerves and can be easily assesed. This article briefly discusses extraocular eye movement at an appropriate level for medical providers like nurses, EMTs, and paramedics.
Video created by Duke University for the course Medical Neuroscience. At this juncture in our exploration of motor control, lets focus on one of the best studied paradigms for understanding the neural control of movement: the eye movement system.
Are the eyes able to fixate, track, and jump from object to object efficiently? In the classroom, normal eye movements allow rapid and accurate shifting of the eyes along a line of print while reading or from book to desk to chalkboardboard. Individuals with poor eye movement skills tend to be poor readers. In sports, efficient eye movements contribute to eye-hand coordination, visual reaction time, and accurate tracking. Recent research has shown that poor eye movement skills influence scores on the Weschler Intelligence Scale for Children and the Iowa Test of Basic Skills. Research has also shown that eye movements can be improved!. ...
The fundamental role of the visual system is to guide behavior in natural environments. In order to optimize information transmission many animals have evolved a non-homogeneous retina and serially sample visual scenes by saccadic eye movements. Such eye movements, however, introduce high-speed retinal motion and decouple external and internal reference frames. Until now, these processes have only been studied with unnatural stimuli, eye movement behavior, and tasks. These experiments confound retinotopic and geotopic coordinate systems and may probe a non-representative functional range. Here we develop a real-time gaze-contingent display with precise spatio-temporal control over high-definition natural movies. In an active condition, human observers freely watched nature documentaries and indicated the location of periodic narrow-band contrast increments relative to their gaze position. In a passive condition under central fixation, the same retinal input was replayed to each observer by ...
L. Itti, Keynote lecture: Computational modeling of bottom-up and top-down visual attention in complex dynamic environments, European Conference on Eye Movements (ECEM 2015), Vienna, Austria, Aug 2015.. Abstract: Visual attention and eye movements in primates have been widely shown to be guided by a combination of stimulus-dependent or bottom-up cues, as well as task-dependent or top-down cues. Both the bottom-up and top-down aspects of attention and eye movements have been modeled computationally. Yet, is is not until recent work which I will describe that bottom-up models have been strictly put to the test, predicting significantly above chance the eye movement patterns, functional neuroimaging activation patterns, or most recently neural activity in the superior colliculus of human or monkey participants inspecting complex static or dynamic scenes. In recent developments, models that increasingly attempt to capture top-down aspects have been proposed. In one system which I will describe, ...
Humans shift their gaze from detail to detail by using eye movements. Although each eye movement changes the position of the image that is reflected to the retinas of the eyes, we experience a spatially stable stream of vision that is uninterrupted by eye movements. To achieve this stable stream of vision, the brain must take into account the eye movement, and temporarily suppress vision during rapid gaze shifts. How the brain does this, remains to be solved. The present research approaches this question from two perspectives. First, we test a theory according to which visual stability is achieved by suppressing in the ability of visual brain areas to communicate with higher brain areas during eye movements. Second, we study whether the disruption of these mechanisms leads to a breakdown in visual stability in specific clinical populations (e.g. Parkinsons disease). Deficits in visual stability could compromise spatial cognition and lead to symptoms such as vertigo and hallucinations ...
This page is under construction. Here we list upcoming conferences and meetings related to eye movements and vision research, which you can browse on the left menu. Please contact us if you would like your event listed here. Other events to be added to menu left:The SWAET (Scandinavian Workshop on Applied Eye Tracking) - a regional variety of the ECEM.
It had long been thought that rodents primarily use their heads rather than their eyes to orient toward salient stimuli (Schneider, 1969). However, with recent advances in high-speed video technology (Stahl, 2004) saccade-like eye movements have been documented in mice with amplitude and speed similar to that of other species (Sakatani and Isa, 2004, 2007). In this study we show that saccadic eye movements can be evoked by microstimulation in the SC, and the amplitudes of these eye movements depend on the stimulation locations. Our results suggest that eye movements in mice and their topographic representations may share similar circuit mechanisms with other well studied species. Given the abundance of genetic tools available in mice, our findings provide an important foundation for future studies using mice to investigate the organization and developmental of sensorimotor transformations in the SC.. In primates, the purpose of saccades is to target the fovea toward locations of interests in ...
FIGURE 5-1. Clinical evaluation of range of eye movements. Versions and cover test measurements allow the examiner to decide whether the eye movements are normal (no limitation) or limited. Forced duction testing is used to differentiate a restriction (positive resistance to movement of the globe) from a paresis (no resistance to movement of the globe).. FIGURE 5-1. Clinical evaluation of range of eye movements. Versions and cover test measurements allow the examiner to decide whether the eye movements are normal (no limitation) or limited. Forced duction testing is used to differentiate a restriction (positive resistance to movement of the globe) from a paresis (no resistance to movement of the globe).. Was this article helpful?. ...
In the paper by Thurtell and colleagues,1 two patients with epilepsy are described in whom in one stimulation over the frontal eye field (FEF) resulted in dysconjugate contraversive horizontal eye movements and in the other similar eye movements were observed as a result of focal seizures (see page 683). The neural system controlling eye movements, particularly rapid conjugate versive movements, called saccades, is one of the most thoroughly understood neural circuits in the brain. It contains a number of cortical centres, … ...
The proposed PhD project will develop and study pattern recognition methods and machine learning techniques for context inference based on eye movement analysis. Potential applications are in activity and health monitoring, location-awareness, assisted living, and cognition-aware user interfaces. The research will be experimental, using portable eye tracking equipment and wearable sensor systems, and will involve user studies and data collection in daily life settings. In addition to experimental skills, the work will require to develop a thorough understanding of pattern recognition, machine learning and statistical signal processing techniques suitable for inferring various aspects of context from eye movements ...
Recent research suggests that when people retrieve information from memory they tend to fixate on the location where the information had appeared during encoding. We used this phenomenon to investigate if different information is activated in memory when people use a rule- versus a similarity-based decision strategy. In two studies, participants first memorized multiple pieces of information about various job candidates (exemplars). In subsequent test trials they judged the suitability of new candidates that varied in their similarity to the previously learned exemplars. Results show that when using similarity, but not when using a rule, participants fixated longer on the previous location of exemplars that resembled the new candidates than on the location of dissimilar exemplars. This suggests that people using similarity retrieve previously learned exemplars, whereas people using a rule do not. The study illustrates that eye movements can provide new insights into the memory processes ...
submitted by [email protected] We are seeking research participants in a study investigating how our eyes move when locating hidden objects. Participants will have their eye movements monitored while they complete a series of computerized visual search tasks. Eligible participants will be given $5 for their participation in this brief experiment.. All adults over 18 years of age with normal or corrected-to-normal vision are eligible to participate. The task takes less than 30 minutes to complete, and there are no anticipated risks to participation. Please contact Samantha Kong via email ([email protected]) if you are interested in participating.. ...
The students have adapted an open-source game called Pong, where a player moves a bat to hit a ball as it bounces around the screen. The adaptation enables the player to move the bat using their eye.. To play the game, the user wears glasses containing an infrared light and a webcam that records the movement of one eye. The webcam is linked to a laptop where a computer program synchronises the players eye movements to the game.. The prototype game is very simple but the students believe that the technology behind it could be adapted to create more sophisticated games and applications such as wheelchairs and computer cursors controlled by eye movements.. The technology was developed using off-the-shelf hardware and cost approximately £25 to make. Eye-movement systems that scientists currently use to study the brain and eye motion cost around £27,000, said the researchers.. Dr Aldo Faisal, the teams supervisor from the Department of Computing and the Department of Bioengineering at Imperial ...
Visual orienting of attention and gaze are widely considered to be mediated by shared neural pathways, with automatic phenomena such as inhibition of return (IOR)--the bias against returning to recently visited locations--being generated via the direct pathway from retina to superior colliculus (SC). Here, we show that IOR occurs without direct access to the SC, by using a technique that employs stimuli visible only to short-wave-sensitive (S) cones. We found that these stimuli, to which the SC is blind , were quite capable of eliciting IOR, measured by traditional manual responses. Critically, however, we found that S cone stimuli did not cause IOR when saccadic eye movement responses were required. This demonstrates that saccadic IOR is not the same as traditional IOR, providing support for two separate cortical and collicular mechanisms of IOR. These findings represent a clear dissociation between visual orienting of attention and gaze.
Eyes normally move only in response to stimuli or direct commands from the brain. If severe, rapid involuntary eye movements may interfere with vision....
This space is for sharing freeware tools related to eye tracking and eye movement research, developing these tools through collaboration, and discussing these tools in related forums. You can browse through current and completed EMRA projects on the left. We always welcome new collaborators, students and senior researchers, manufacturers and industrial members who are willing
Eye-tracking aims to determine where one directs ones gaze, or, put simply, it where one looks (for instance, on a computer monitor). Because of the richness and importance of visual information in the environment and because the acuity (sharpness) of human vision rapidly falls off as one departs from the centre of the gazes focus, humans have evolved to possess a powerful (fast and effective) oculomotor system: six muscles that move the eye-ball in the eye-socket guided by groups of cells in several regions of the brain, most notably in the superior colliculus and frontal eye fields. The behaviour of the oculomotor system is characterised by two states: the gaze is either (virtually) stationary- referred to as fixation- or it is on a fast move- referred to as saccade. Since research to date has convincingly shown that no information is acquired during the eye-movement (saccade), which means we only see during the fixation, psychologists tend to be interested in the latter: the location ...
United States News: Comcast users can now change channels with eye movements - Pennsylvania , June 17 : Changing channels on your Comcast X1 will be truly hands-free as the company is adding eye control to its cable platform.
New research shows that the brain area involved in eye movements is also involved in transmitting information to the visual cortex.
Researchers are interested in studying the changes in eye movement that accompany the development of neurodegenerative conditions such as Alzheimers and Parkinsons Disease.
Indeed, both humans and monkeys make two to three fast eye movements every second in this manner, with each eye-movement lasting less than one-tenth of a second. Because the eye acts like a camera, each eye-movement results in a different view of the scene falling onto the retina.. However, despite these fast changes in viewpoint (which can also result from head movements), humans and monkeys do not see a scene that jumps around: Instead, they are able to "stitch together" the information obtained during each fixation to perceive a stable visual scene. They are also able to keep track of where relevant objects are in the scene even with these frequent changes in viewpoint. This is a very challenging task. Visual neurons respond more to relevant objects than to irrelevant ones. This increased response to relevant stimuli "marks" relevant stimuli.. Since each visual neuron in the brain only responds when a specific part of the retina is stimulated, each change in viewpoint with an eye-movement ...
Lucid dream science has come a long way in the last few decides, culminating in recent research using brainwave, bloodflow and eye movement data.
Later in the article, the authors note that there has been a lot of debate about what drives saccadic eye movements, not only in a specialized task like drawing, but in normal viewing. Are our eye movements passively driven by features in the scene, or are they actively controlled by the conscious attention? I would suspect that its a combination of the two, and that artists in the act of drawing are much more on the "active control" end of the spectrum ...
This project explores the utility of eye-tracking in the study of literary devices characteristic of both Modernist literature and the popular crime/thriller genre. Experimenters typically use simple texts of only a sentence or two rather than real literary texts. Our studies will increase scientific understanding of how authentic literary texts are read, as well as demonstrate the value of complementing theoretical claims about literary devices with empirical testing.
bestbooklibrary matches keywords, searched from 3rd-party sites, to affiliate-networks offering unlimited access to licensed entertainment content. bestbooklibrary allows visitors, otherwise looking for free-content to enjoy more for less. ...
아이의 움직임 감시 (또는 눈 추적)이 공간에 눈을 이만 남았 어디에 공개, 언제, 어떻게 오래. 여기, 우리는 언어적,하거나 노골적인보고를 요구하지 않고, 안구 추적 여러 참가자 집단에 메모리의 무결성을 조사하는 데 사용할 수있는 방법을...
Microsoft is continuing to push quietly into new frontiers on the accessibility front. Their most recent effort? The release of four free Eyes F...
I experimented with a slightly different position of the sensors in the halograph. Although the eye movements are a lot weaker than normal, they were luckily just strong enough for the algorithm to detect. 12 blinks can be seen in the minute above when the track was almost seamlessly integrated into the dream. Download entry…
In a study published in Current Biology researchers at Karolinska Institutet show that our eye movements are partly governed by our genes.
Simulates eye motion (the eyes follow the pointer) and demonstrates the effects of disabling one or more of the 12 eye muscles and one or more of the 6 cranial nerves that control eye motion. Requires Shockwave. ...