Multipulse control of saccadic eye movements

NASA Technical Reports Server (NTRS)

Lehman, S. L.; Stark, L.

1981-01-01

We present three conclusions regarding the neural control of saccadic eye movements, resulting from comparisons between recorded movements and computer simulations. The controller signal to the muscles is probably a multipulse-step. This kind of signal drives the fastest model trajectories. Finally, multipulse signals explain differences between model and electrophysiological results.

Looking around: 35 years of oculomotor modeling

NASA Technical Reports Server (NTRS)

Young, L. R.

1995-01-01

Eye movements have attracted an unusually large number of researchers from many disparate fields, especially over the past 35 years. The lure of this system stemmed from its apparent simplicity of description, measurement, and analysis, as well as the promise of providing a "window in the mind." Investigators in areas ranging from biological control systems and neurological diagnosis to applications in advertising and flight simulation expected eye movements to provide clear indicators of what the sensory-motor system was accomplishing and what the brain found to be of interest. The parallels between compensatory eye movements and perception of spatial orientation have been a subject for active study in visual-vestibular interaction, where substantial knowledge has accumulated through experiments largely guided by the challenge of proving or disproving model predictions. Even though oculomotor control has arguably benefited more from systems theory than any other branch of motor control, many of the original goals remain largely unfulfilled. This paper considers some of the promising potential benefits of eye movement research and compares accomplishments with anticipated results. Four topics are considered in greater detail: (i) the definition of oculomotor system input and output, (ii) optimization of the eye movement system, (iii) the relationship between compensatory eye movements and spatial orientation through the "internal model," and (iv) the significance of eye movements as measured in (outer) space.

Looking around: 35 years of oculomotor modeling.

PubMed

Young, L R

1995-01-01

Eye movements have attracted an unusually large number of researchers from many disparate fields, especially over the past 35 years. The lure of this system stemmed from its apparent simplicity of description, measurement, and analysis, as well as the promise of providing a "window in the mind." Investigators in areas ranging from biological control systems and neurological diagnosis to applications in advertising and flight simulation expected eye movements to provide clear indicators of what the sensory-motor system was accomplishing and what the brain found to be of interest. The parallels between compensatory eye movements and perception of spatial orientation have been a subject for active study in visual-vestibular interaction, where substantial knowledge has accumulated through experiments largely guided by the challenge of proving or disproving model predictions. Even though oculomotor control has arguably benefited more from systems theory than any other branch of motor control, many of the original goals remain largely unfulfilled. This paper considers some of the promising potential benefits of eye movement research and compares accomplishments with anticipated results. Four topics are considered in greater detail: (i) the definition of oculomotor system input and output, (ii) optimization of the eye movement system, (iii) the relationship between compensatory eye movements and spatial orientation through the "internal model," and (iv) the significance of eye movements as measured in (outer) space.

Eye Movement Control during Reading: I. The Location of Initial Eye Fixations on Words. Technical Report No. 406.

ERIC Educational Resources Information Center

McConkie, G. W.; And Others

Sixty-six college students read two chapters from a contemporary novel while their eye movements were monitored. The eye movement data were analyzed to identify factors that influence the location of a reader's initial eye fixation on a word. When the data were partitioned according to the location of the prior fixation (i.e., launch site), the…

Eye Movement Control during Scene Viewing: Immediate Effects of Scene Luminance on Fixation Durations

ERIC Educational Resources Information Center

Henderson, John M.; Nuthmann, Antje; Luke, Steven G.

2013-01-01

Recent research on eye movements during scene viewing has primarily focused on where the eyes fixate. But eye fixations also differ in their durations. Here we investigated whether fixation durations in scene viewing are under the direct and immediate control of the current visual input. Subjects freely viewed photographs of scenes in preparation…

Real time eye tracking using Kalman extended spatio-temporal context learning

NASA Astrophysics Data System (ADS)

Munir, Farzeen; Minhas, Fayyaz ul Amir Asfar; Jalil, Abdul; Jeon, Moongu

2017-06-01

Real time eye tracking has numerous applications in human computer interaction such as a mouse cursor control in a computer system. It is useful for persons with muscular or motion impairments. However, tracking the movement of the eye is complicated by occlusion due to blinking, head movement, screen glare, rapid eye movements, etc. In this work, we present the algorithmic and construction details of a real time eye tracking system. Our proposed system is an extension of Spatio-Temporal context learning through Kalman Filtering. Spatio-Temporal Context Learning offers state of the art accuracy in general object tracking but its performance suffers due to object occlusion. Addition of the Kalman filter allows the proposed method to model the dynamics of the motion of the eye and provide robust eye tracking in cases of occlusion. We demonstrate the effectiveness of this tracking technique by controlling the computer cursor in real time by eye movements.

Basal Ganglia Neuronal Activity during Scanning Eye Movements in Parkinson’s Disease

PubMed Central

Sieger, Tomáš; Bonnet, Cecilia; Serranová, Tereza; Wild, Jiří; Novák, Daniel; Růžička, Filip; Urgošík, Dušan; Růžička, Evžen; Gaymard, Bertrand; Jech, Robert

2013-01-01

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control. PMID:24223158

Eye movements and attention in reading, scene perception, and visual search.

PubMed

Rayner, Keith

2009-08-01

Eye movements are now widely used to investigate cognitive processes during reading, scene perception, and visual search. In this article, research on the following topics is reviewed with respect to reading: (a) the perceptual span (or span of effective vision), (b) preview benefit, (c) eye movement control, and (d) models of eye movements. Related issues with respect to eye movements during scene perception and visual search are also reviewed. It is argued that research on eye movements during reading has been somewhat advanced over research on eye movements in scene perception and visual search and that some of the paradigms developed to study reading should be more widely adopted in the study of scene perception and visual search. Research dealing with "real-world" tasks and research utilizing the visual-world paradigm are also briefly discussed.

The Trajectories of Saccadic Eye Movements.

ERIC Educational Resources Information Center

Bahill, A. Terry; Stark, Lawrence

1979-01-01

Investigates the trajectories of saccadic eye movements, the control signals of the eye, and nature of the mechanisms that generate them, using the techniques of bioengineering in collecting the data. (GA)

How young adults with autism spectrum disorder watch and interpret pragmatically complex scenes.

PubMed

Lönnqvist, Linda; Loukusa, Soile; Hurtig, Tuula; Mäkinen, Leena; Siipo, Antti; Väyrynen, Eero; Palo, Pertti; Laukka, Seppo; Mämmelä, Laura; Mattila, Marja-Leena; Ebeling, Hanna

2017-11-01

The aim of the current study was to investigate subtle characteristics of social perception and interpretation in high-functioning individuals with autism spectrum disorders (ASDs), and to study the relation between watching and interpreting. As a novelty, we used an approach that combined moment-by-moment eye tracking and verbal assessment. Sixteen young adults with ASD and 16 neurotypical control participants watched a video depicting a complex communication situation while their eye movements were tracked. The participants also completed a verbal task with questions related to the pragmatic content of the video. We compared verbal task scores and eye movements between groups, and assessed correlations between task performance and eye movements. Individuals with ASD had more difficulty than the controls in interpreting the video, and during two short moments there were significant group differences in eye movements. Additionally, we found significant correlations between verbal task scores and moment-level eye movement in the ASD group, but not among the controls. We concluded that participants with ASD had slight difficulties in understanding the pragmatic content of the video stimulus and attending to social cues, and that the connection between pragmatic understanding and eye movements was more pronounced for participants with ASD than for neurotypical participants.

The adaptive nature of eye movements in linguistic tasks: how payoff and architecture shape speed-accuracy trade-offs.

PubMed

Lewis, Richard L; Shvartsman, Michael; Singh, Satinder

2013-07-01

We explore the idea that eye-movement strategies in reading are precisely adapted to the joint constraints of task structure, task payoff, and processing architecture. We present a model of saccadic control that separates a parametric control policy space from a parametric machine architecture, the latter based on a small set of assumptions derived from research on eye movements in reading (Engbert, Nuthmann, Richter, & Kliegl, 2005; Reichle, Warren, & McConnell, 2009). The eye-control model is embedded in a decision architecture (a machine and policy space) that is capable of performing a simple linguistic task integrating information across saccades. Model predictions are derived by jointly optimizing the control of eye movements and task decisions under payoffs that quantitatively express different desired speed-accuracy trade-offs. The model yields distinct eye-movement predictions for the same task under different payoffs, including single-fixation durations, frequency effects, accuracy effects, and list position effects, and their modulation by task payoff. The predictions are compared to-and found to accord with-eye-movement data obtained from human participants performing the same task under the same payoffs, but they are found not to accord as well when the assumptions concerning payoff optimization and processing architecture are varied. These results extend work on rational analysis of oculomotor control and adaptation of reading strategy (Bicknell & Levy, ; McConkie, Rayner, & Wilson, 1973; Norris, 2009; Wotschack, 2009) by providing evidence for adaptation at low levels of saccadic control that is shaped by quantitatively varying task demands and the dynamics of processing architecture. Copyright © 2013 Cognitive Science Society, Inc.

Image-based computer-assisted diagnosis system for benign paroxysmal positional vertigo

NASA Astrophysics Data System (ADS)

Kohigashi, Satoru; Nakamae, Koji; Fujioka, Hiromu

2005-04-01

We develop the image based computer assisted diagnosis system for benign paroxysmal positional vertigo (BPPV) that consists of the balance control system simulator, the 3D eye movement simulator, and the extraction method of nystagmus response directly from an eye movement image sequence. In the system, the causes and conditions of BPPV are estimated by searching the database for record matching with the nystagmus response for the observed eye image sequence of the patient with BPPV. The database includes the nystagmus responses for simulated eye movement sequences. The eye movement velocity is obtained by using the balance control system simulator that allows us to simulate BPPV under various conditions such as canalithiasis, cupulolithiasis, number of otoconia, otoconium size, and so on. Then the eye movement image sequence is displayed on the CRT by the 3D eye movement simulator. The nystagmus responses are extracted from the image sequence by the proposed method and are stored in the database. In order to enhance the diagnosis accuracy, the nystagmus response for a newly simulated sequence is matched with that for the observed sequence. From the matched simulation conditions, the causes and conditions of BPPV are estimated. We apply our image based computer assisted diagnosis system to two real eye movement image sequences for patients with BPPV to show its validity.

Binocular eye movement control and motion perception: what is being tracked?

PubMed

van der Steen, Johannes; Dits, Joyce

2012-10-19

We investigated under what conditions humans can make independent slow phase eye movements. The ability to make independent movements of the two eyes generally is attributed to few specialized lateral eyed animal species, for example chameleons. In our study, we showed that humans also can move the eyes in different directions. To maintain binocular retinal correspondence independent slow phase movements of each eye are produced. We used the scleral search coil method to measure binocular eye movements in response to dichoptically viewed visual stimuli oscillating in orthogonal direction. Correlated stimuli led to orthogonal slow eye movements, while the binocularly perceived motion was the vector sum of the motion presented to each eye. The importance of binocular fusion on independency of the movements of the two eyes was investigated with anti-correlated stimuli. The perceived global motion pattern of anti-correlated dichoptic stimuli was perceived as an oblique oscillatory motion, as well as resulted in a conjugate oblique motion of the eyes. We propose that the ability to make independent slow phase eye movements in humans is used to maintain binocular retinal correspondence. Eye-of-origin and binocular information are used during the processing of binocular visual information, and it is decided at an early stage whether binocular or monocular motion information and independent slow phase eye movements of each eye are produced during binocular tracking.

Binocular Eye Movement Control and Motion Perception: What Is Being Tracked?

PubMed Central

van der Steen, Johannes; Dits, Joyce

2012-01-01

Purpose. We investigated under what conditions humans can make independent slow phase eye movements. The ability to make independent movements of the two eyes generally is attributed to few specialized lateral eyed animal species, for example chameleons. In our study, we showed that humans also can move the eyes in different directions. To maintain binocular retinal correspondence independent slow phase movements of each eye are produced. Methods. We used the scleral search coil method to measure binocular eye movements in response to dichoptically viewed visual stimuli oscillating in orthogonal direction. Results. Correlated stimuli led to orthogonal slow eye movements, while the binocularly perceived motion was the vector sum of the motion presented to each eye. The importance of binocular fusion on independency of the movements of the two eyes was investigated with anti-correlated stimuli. The perceived global motion pattern of anti-correlated dichoptic stimuli was perceived as an oblique oscillatory motion, as well as resulted in a conjugate oblique motion of the eyes. Conclusions. We propose that the ability to make independent slow phase eye movements in humans is used to maintain binocular retinal correspondence. Eye-of-origin and binocular information are used during the processing of binocular visual information, and it is decided at an early stage whether binocular or monocular motion information and independent slow phase eye movements of each eye are produced during binocular tracking. PMID:22997286

Cardiac autonomic denervation in Parkinson's disease is linked to REM sleep behavior disorder.

PubMed

Postuma, Ronald B; Montplaisir, Jacques; Lanfranchi, Paola; Blais, Hélène; Rompré, Sylvie; Colombo, Roberto; Gagnon, Jean-François

2011-07-01

Recent studies have suggested a close connection between autonomic dysfunction and rapid eye movement sleep behavior disorder, which differs in nature from other early-stage markers of Parkinson's disease. In this study we examined the relationship between rapid eye movement sleep behavior disorder and autonomic dysfunction in Parkinson's disease as measured by cardiac beat-to-beat variability. In 53 patients with Parkinson's disease and 36 controls, electrocardiographic trace from a polysomnogram was assessed for measures of beat-to-beat RR variability including RR-standard deviation and frequency domains (low- and high-frequency components). Results were compared between patients with Parkinson's disease and controls, and between patients with Parkinson's disease with and without rapid eye movement sleep behavior disorder. On numerous cardiac autonomic measures, patients with Parkinson's disease showed clear abnormalities compared with controls. However, these abnormalities were confined only to those patients with associated rapid eye movement sleep behavior; those without were not different than controls. As with other clinical autonomic variables, cardiac autonomic denervation is predominantly associated not with Parkinson's disease itself, but with the presence of rapid eye movement sleep behavior disorder. Copyright © 2011 Movement Disorder Society.

Comparison for aphasic and control subjects of eye movements hypothesized in neurolinguistic programming.

PubMed

Dooley, K O; Farmer, A

1988-08-01

Neurolinguistic programming's hypothesized eye movements were measured independently using videotapes of 10 nonfluent aphasic and 10 control subjects matched for age and sex. Chi-squared analysis indicated that eye-position responses were significantly different for the groups. Although earlier research has not supported the hypothesized eye positions for normal subjects, the present findings support the contention that eye-position responses may differ between neurologically normal and aphasic individuals.

SmartEye and Polhemus data for vestibulo-ocular reflex and optokinetic reflex model.

PubMed

Le, Anh Son; Aoki, Hirofumi

2018-06-01

In this data article, this dataset included raw data of head and eye movement that collected by Polhemus (Polhemus Inc) and SmartEye (Smart Eye AB) equipment. Subjects who have driver license participated in this experiment. The experiment was conducted with a driving simulator that was controlled by CarSim (Mechanical simulation Co., Anna Arbor, MI) with the vehicle motion. This data set not only contained the eye and head movement but also had eye gaze, pupil diameter, saccades, and so on. It can be used for the parameter identification of the vestibulor-ocular reflex (VOR) model, simulation eye movement, as well as running other analysis related to eye movement.

Using E-Z Reader to Simulate Eye Movements in Nonreading Tasks: A Unified Framework for Understanding the Eye-Mind Link

ERIC Educational Resources Information Center

Reichle, Erik D.; Pollatsek, Alexander; Rayner, Keith

2012-01-01

Nonreading tasks that share some (but not all) of the task demands of reading have often been used to make inferences about how cognition influences when the eyes move during reading. In this article, we use variants of the E-Z Reader model of eye-movement control in reading to simulate eye-movement behavior in several of these tasks, including…

Eye-head coordination during free exploration in human and cat.

PubMed

Einhäuser, Wolfgang; Moeller, Gudrun U; Schumann, Frank; Conradt, Jörg; Vockeroth, Johannes; Bartl, Klaus; Schneider, Erich; König, Peter

2009-05-01

Eye, head, and body movements jointly control the direction of gaze and the stability of retinal images in most mammalian species. The contribution of the individual movement components, however, will largely depend on the ecological niche the animal occupies and the layout of the animal's retina, in particular its photoreceptor density distribution. Here the relative contribution of eye-in-head and head-in-world movements in cats is measured, and the results are compared to recent human data. For the cat, a lightweight custom-made head-mounted video setup was used (CatCam). Human data were acquired with the novel EyeSeeCam device, which measures eye position to control a gaze-contingent camera in real time. For both species, analysis was based on simultaneous recordings of eye and head movements during free exploration of a natural environment. Despite the substantial differences in ecological niche, photoreceptor density, and saccade frequency, eye-movement characteristics in both species are remarkably similar. Coordinated eye and head movements dominate the dynamics of the retinal input. Interestingly, compensatory (gaze-stabilizing) movements play a more dominant role in humans than they do in cats. This finding was interpreted to be a consequence of substantially different timescales for head movements, with cats' head movements showing about a 5-fold faster dynamics than humans. For both species, models and laboratory experiments therefore need to account for this rich input dynamic to obtain validity for ecologically realistic settings.

Coordination of eye and head components of movements evoked by stimulation of the paramedian pontine reticular formation.

PubMed

Gandhi, Neeraj J; Barton, Ellen J; Sparks, David L

2008-07-01

Constant frequency microstimulation of the paramedian pontine reticular formation (PPRF) in head-restrained monkeys evokes a constant velocity eye movement. Since the PPRF receives significant projections from structures that control coordinated eye-head movements, we asked whether stimulation of the pontine reticular formation in the head-unrestrained animal generates a combined eye-head movement or only an eye movement. Microstimulation of most sites yielded a constant-velocity gaze shift executed as a coordinated eye-head movement, although eye-only movements were evoked from some sites. The eye and head contributions to the stimulation-evoked movements varied across stimulation sites and were drastically different from the lawful relationship observed for visually-guided gaze shifts. These results indicate that the microstimulation activated elements that issued movement commands to the extraocular and, for most sites, neck motoneurons. In addition, the stimulation-evoked changes in gaze were similar in the head-restrained and head-unrestrained conditions despite the assortment of eye and head contributions, suggesting that the vestibulo-ocular reflex (VOR) gain must be near unity during the coordinated eye-head movements evoked by stimulation of the PPRF. These findings contrast the attenuation of VOR gain associated with visually-guided gaze shifts and suggest that the vestibulo-ocular pathway processes volitional and PPRF stimulation-evoked gaze shifts differently.

Asymmetries in the Control of Saccadic Eye Movements to Bifurcating Targets.

ERIC Educational Resources Information Center

Zeevi, Yehoshua Y.; And Others

The examination of saccadic eye movements--rapid shifts in gaze from one visual area of interest to another--is useful in studying pilot's visual learning in flight simulator training. Saccadic eye movements are the basic oculomotor response associated with the acquisition of visual information and provide an objective measure of higher perceptual…

Using Eye Movement to Control a Computer: A Design for a Lightweight Electro-Oculogram Electrode Array and Computer Interface

PubMed Central

Iáñez, Eduardo; Azorin, Jose M.; Perez-Vidal, Carlos

2013-01-01

This paper describes a human-computer interface based on electro-oculography (EOG) that allows interaction with a computer using eye movement. The EOG registers the movement of the eye by measuring, through electrodes, the difference of potential between the cornea and the retina. A new pair of EOG glasses have been designed to improve the user's comfort and to remove the manual procedure of placing the EOG electrodes around the user's eye. The interface, which includes the EOG electrodes, uses a new processing algorithm that is able to detect the gaze direction and the blink of the eyes from the EOG signals. The system reliably enabled subjects to control the movement of a dot on a video screen. PMID:23843986

Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

NASA Technical Reports Server (NTRS)

Kamine, Tovy Haber; Bendrick, Gregg A.

2008-01-01

Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. cones ) of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of Maximum Eye Movement. However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of Easy Eye Movement, though all were within the cone of Maximum Eye Movement. All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Most instrument displays in conventional aircraft lay within the cone of Easy Eye Movement, though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight. The learning objectives include: 1) Know three physiologic cones of eye/head movement; 2) Understand how instrument displays comply with these design principles in conventional aircraft and an uninhabited aerial vehicle system. Which of the following is NOT a recognized physiologic principle of instrument display design? Cone of Easy Eye Movement 2) Cone of Binocular Eye Movement 3) Cone of Maximum Eye Movement 4) Cone of Head Movement 5) None of the above. Answer: # 2) Cone of Binocular Eye Movement

Eye Movements During Everyday Behavior Predict Personality Traits.

PubMed

Hoppe, Sabrina; Loetscher, Tobias; Morey, Stephanie A; Bulling, Andreas

2018-01-01

Besides allowing us to perceive our surroundings, eye movements are also a window into our mind and a rich source of information on who we are, how we feel, and what we do. Here we show that eye movements during an everyday task predict aspects of our personality. We tracked eye movements of 42 participants while they ran an errand on a university campus and subsequently assessed their personality traits using well-established questionnaires. Using a state-of-the-art machine learning method and a rich set of features encoding different eye movement characteristics, we were able to reliably predict four of the Big Five personality traits (neuroticism, extraversion, agreeableness, conscientiousness) as well as perceptual curiosity only from eye movements. Further analysis revealed new relations between previously neglected eye movement characteristics and personality. Our findings demonstrate a considerable influence of personality on everyday eye movement control, thereby complementing earlier studies in laboratory settings. Improving automatic recognition and interpretation of human social signals is an important endeavor, enabling innovative design of human-computer systems capable of sensing spontaneous natural user behavior to facilitate efficient interaction and personalization.

Eye Movements During Everyday Behavior Predict Personality Traits

PubMed Central

Hoppe, Sabrina; Loetscher, Tobias; Morey, Stephanie A.; Bulling, Andreas

2018-01-01

Besides allowing us to perceive our surroundings, eye movements are also a window into our mind and a rich source of information on who we are, how we feel, and what we do. Here we show that eye movements during an everyday task predict aspects of our personality. We tracked eye movements of 42 participants while they ran an errand on a university campus and subsequently assessed their personality traits using well-established questionnaires. Using a state-of-the-art machine learning method and a rich set of features encoding different eye movement characteristics, we were able to reliably predict four of the Big Five personality traits (neuroticism, extraversion, agreeableness, conscientiousness) as well as perceptual curiosity only from eye movements. Further analysis revealed new relations between previously neglected eye movement characteristics and personality. Our findings demonstrate a considerable influence of personality on everyday eye movement control, thereby complementing earlier studies in laboratory settings. Improving automatic recognition and interpretation of human social signals is an important endeavor, enabling innovative design of human–computer systems capable of sensing spontaneous natural user behavior to facilitate efficient interaction and personalization. PMID:29713270

Eye Movement Indices in the Study of Depressive Disorder

PubMed Central

LI, Yu; XU, Yangyang; XIA, Mengqing; ZHANG, Tianhong; WANG, Junjie; LIU, Xu; HE, Yongguang; WANG, Jijun

2016-01-01

Background Impaired cognition is one of the most common core symptoms of depressive disorder. Eye movement testing mainly reflects patients’ cognitive functions, such as cognition, memory, attention, recognition, and recall. This type of testing has great potential to improve theories related to cognitive functioning in depressive episodes as well as potential in its clinical application. Aims This study investigated whether eye movement indices of patients with unmedicated depressive disorder were abnormal or not, as well as the relationship between these indices and mental symptoms. Methods Sixty patients with depressive disorder and sixty healthy controls (who were matched by gender, age and years of education) were recruited, and completed eye movement tests including three tasks: fixation task, saccade task and free-view task. The EyeLink desktop eye tracking system was employed to collect eye movement information, and analyze the eye movement indices of the three tasks between the two groups. Results (1) In the fixation task, compared to healthy controls, patients with depressive disorder showed more fixations, shorter fixation durations, more saccades and longer saccadic lengths; (2) In the saccade task, patients with depressive disorder showed longer anti-saccade latencies and smaller anti-saccade peak velocities; (3) In the free-view task, patients with depressive disorder showed fewer saccades and longer mean fixation durations; (4) Correlation analysis showed that there was a negative correlation between the pro-saccade amplitude and anxiety symptoms, and a positive correlation between the anti-saccade latency and anxiety symptoms. The depression symptoms were negatively correlated with fixation times, saccades, and saccadic paths respectively in the free-view task; while the mean fixation duration and depression symptoms showed a positive correlation. Conclusion Compared to healthy controls, patients with depressive disorder showed significantly abnormal eye movement indices. In addition patients’ anxiety and depression symptoms and eye movement indices were correlated. The pathological meaning of these phenomena deserve further exploration. PMID:28638208

Eye Movement Indices in the Study of Depressive Disorder.

PubMed

Li, Yu; Xu, Yangyang; Xia, Mengqing; Zhang, Tianhong; Wang, Junjie; Liu, Xu; He, Yongguang; Wang, Jijun

2016-12-25

Impaired cognition is one of the most common core symptoms of depressive disorder. Eye movement testing mainly reflects patients' cognitive functions, such as cognition, memory, attention, recognition, and recall. This type of testing has great potential to improve theories related to cognitive functioning in depressive episodes as well as potential in its clinical application. This study investigated whether eye movement indices of patients with unmedicated depressive disorder were abnormal or not, as well as the relationship between these indices and mental symptoms. Sixty patients with depressive disorder and sixty healthy controls (who were matched by gender, age and years of education) were recruited, and completed eye movement tests including three tasks: fixation task, saccade task and free-view task. The EyeLink desktop eye tracking system was employed to collect eye movement information, and analyze the eye movement indices of the three tasks between the two groups. (1) In the fixation task, compared to healthy controls, patients with depressive disorder showed more fixations, shorter fixation durations, more saccades and longer saccadic lengths; (2) In the saccade task, patients with depressive disorder showed longer anti-saccade latencies and smaller anti-saccade peak velocities; (3) In the free-view task, patients with depressive disorder showed fewer saccades and longer mean fixation durations; (4) Correlation analysis showed that there was a negative correlation between the pro-saccade amplitude and anxiety symptoms, and a positive correlation between the anti-saccade latency and anxiety symptoms. The depression symptoms were negatively correlated with fixation times, saccades, and saccadic paths respectively in the free-view task; while the mean fixation duration and depression symptoms showed a positive correlation. Compared to healthy controls, patients with depressive disorder showed significantly abnormal eye movement indices. In addition patients' anxiety and depression symptoms and eye movement indices were correlated. The pathological meaning of these phenomena deserve further exploration.

Does the perception of moving eyes trigger reflexive visual orienting in autism?

PubMed Central

Swettenham, John; Condie, Samantha; Campbell, Ruth; Milne, Elizabeth; Coleman, Mike

2003-01-01

Does movement of the eyes in one or another direction function as an automatic attentional cue to a location of interest? Two experiments explored the directional movement of the eyes in a full face for speed of detection of an aftercoming location target in young people with autism and in control participants. Our aim was to investigate whether a low-level perceptual impairment underlies the delay in gaze following characteristic of autism. The participants' task was to detect a target appearing on the left or right of the screen either 100 ms or 800 ms after a face cue appeared with eyes averting to the left or right. Despite instructions to ignore eye-movement in the face cue, people with autism and control adolescents were quicker to detect targets that had been preceded by an eye movement cue congruent with target location compared with targets preceded by an incongruent eye movement cue. The attention shifts are thought to be reflexive because the cue was to be ignored, and because the effect was found even when cue-target duration was short (100 ms). Because (experiment two) the effect persisted even when the face was inverted, it would seem that the direction of movement of eyes can provide a powerful (involuntary) cue to a location. PMID:12639330

Constraining eye movement in individuals with Parkinson's disease during walking turns.

PubMed

Ambati, V N Pradeep; Saucedo, Fabricio; Murray, Nicholas G; Powell, Douglas W; Reed-Jones, Rebecca J

2016-10-01

Walking and turning is a movement that places individuals with Parkinson's disease (PD) at increased risk for fall-related injury. However, turning is an essential movement in activities of daily living, making up to 45 % of the total steps taken in a given day. Hypotheses regarding how turning is controlled suggest an essential role of anticipatory eye movements to provide feedforward information for body coordination. However, little research has investigated control of turning in individuals with PD with specific consideration for eye movements. The purpose of this study was to examine eye movement behavior and body segment coordination in individuals with PD during walking turns. Three experimental groups, a group of individuals with PD, a group of healthy young adults (YAC), and a group of healthy older adults (OAC), performed walking and turning tasks under two visual conditions: free gaze and fixed gaze. Whole-body motion capture and eye tracking characterized body segment coordination and eye movement behavior during walking trials. Statistical analysis revealed significant main effects of group (PD, YAC, and OAC) and visual condition (free and fixed gaze) on timing of segment rotation and horizontal eye movement. Within group comparisons, revealed timing of eye and head movement was significantly different between the free and fixed gaze conditions for YAC (p < 0.001) and OAC (p < 0.05), but not for the PD group (p > 0.05). In addition, while intersegment timings (reflecting segment coordination) were significantly different for YAC and OAC during free gaze (p < 0.05), they were not significantly different in PD. These results suggest individuals with PD do not make anticipatory eye and head movements ahead of turning and that this may result in altered segment coordination during turning. As such, eye movements may be an important addition to training programs for those with PD, possibly promoting better coordination during turning and potentially reducing the risk of falls.

Exploring eye movements in patients with glaucoma when viewing a driving scene.

PubMed

Crabb, David P; Smith, Nicholas D; Rauscher, Franziska G; Chisholm, Catharine M; Barbur, John L; Edgar, David F; Garway-Heath, David F

2010-03-16

Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for fitness to drive.

Exploring Eye Movements in Patients with Glaucoma When Viewing a Driving Scene

PubMed Central

Crabb, David P.; Smith, Nicholas D.; Rauscher, Franziska G.; Chisholm, Catharine M.; Barbur, John L.; Edgar, David F.; Garway-Heath, David F.

2010-01-01

Background Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). Methodology/Principal Findings The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of ‘point-of-regard’ of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Conclusions/Significance Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for fitness to drive. PMID:20300522

Dissociation of eye and head components of gaze shifts by stimulation of the omnipause neuron region.

PubMed

Gandhi, Neeraj J; Sparks, David L

2007-07-01

Natural movements often include actions integrated across multiple effectors. Coordinated eye-head movements are driven by a command to shift the line of sight by a desired displacement vector. Yet because extraocular and neck motoneurons are separate entities, the gaze shift command must be separated into independent signals for eye and head movement control. We report that this separation occurs, at least partially, at or before the level of pontine omnipause neurons (OPNs). Stimulation of the OPNs prior to and during gaze shifts temporally decoupled the eye and head components by inhibiting gaze and eye saccades. In contrast, head movements were consistently initiated before gaze onset, and ongoing head movements continued along their trajectories, albeit with some characteristic modulations. After stimulation offset, a gaze shift composed of an eye saccade, and a reaccelerated head movement was produced to preserve gaze accuracy. We conclude that signals subject to OPN inhibition produce the eye-movement component of a coordinated eye-head gaze shift and are not the only signals involved in the generation of the head component of the gaze shift.

Trained Eyes: Experience Promotes Adaptive Gaze Control in Dynamic and Uncertain Visual Environments

PubMed Central

Taya, Shuichiro; Windridge, David; Osman, Magda

2013-01-01

Current eye-tracking research suggests that our eyes make anticipatory movements to a location that is relevant for a forthcoming task. Moreover, there is evidence to suggest that with more practice anticipatory gaze control can improve. However, these findings are largely limited to situations where participants are actively engaged in a task. We ask: does experience modulate anticipative gaze control while passively observing a visual scene? To tackle this we tested people with varying degrees of experience of tennis, in order to uncover potential associations between experience and eye movement behaviour while they watched tennis videos. The number, size, and accuracy of saccades (rapid eye-movements) made around ‘events,’ which is critical for the scene context (i.e. hit and bounce) were analysed. Overall, we found that experience improved anticipatory eye-movements while watching tennis clips. In general, those with extensive experience showed greater accuracy of saccades to upcoming event locations; this was particularly prevalent for events in the scene that carried high uncertainty (i.e. ball bounces). The results indicate that, even when passively observing, our gaze control system utilizes prior relevant knowledge in order to anticipate upcoming uncertain event locations. PMID:23951147

Instrument scanning and controlling: Using eye movement data to understand pilot behavior and strategies

NASA Technical Reports Server (NTRS)

Dick, A. O.

1980-01-01

Eye movement data and other parameters including instrument readings, aircraft state and position variables, and control maneuvers were recorded while pilots flew ILS simulations in a B 737. The experiment itself employed seven airline pilots, each of whom flew approximately 40 approach/landing sequences. The simulator was equipped with a night visual scene but the scene was fogged out down to approximately 60 meters (200 ft). The instrument scanning appeared to follow aircraft parameters not physical position of instruments. One important implication of the results is: pilots look for categories or packets of information. Control inputs were tabulated according to throttle, wheel position, column, and pitch trim changes. Three seconds of eye movements before and after the control input were then obtained. Analysis of the eye movement data for the controlling periods showed clear patterns. The results suggest a set of miniscan patterns which are used according to the specific details of the situation. A model is developed which integrates scanning and controlling. Differentiations are made between monitoring and controlling scans.

Towards free 3D end-point control for robotic-assisted human reaching using binocular eye tracking.

PubMed

Maimon-Dror, Roni O; Fernandez-Quesada, Jorge; Zito, Giuseppe A; Konnaris, Charalambos; Dziemian, Sabine; Faisal, A Aldo

2017-07-01

Eye-movements are the only directly observable behavioural signals that are highly correlated with actions at the task level, and proactive of body movements and thus reflect action intentions. Moreover, eye movements are preserved in many movement disorders leading to paralysis (or amputees) from stroke, spinal cord injury, Parkinson's disease, multiple sclerosis, and muscular dystrophy among others. Despite this benefit, eye tracking is not widely used as control interface for robotic interfaces in movement impaired patients due to poor human-robot interfaces. We demonstrate here how combining 3D gaze tracking using our GT3D binocular eye tracker with custom designed 3D head tracking system and calibration method enables continuous 3D end-point control of a robotic arm support system. The users can move their own hand to any location of the workspace by simple looking at the target and winking once. This purely eye tracking based system enables the end-user to retain free head movement and yet achieves high spatial end point accuracy in the order of 6 cm RMSE error in each dimension and standard deviation of 4 cm. 3D calibration is achieved by moving the robot along a 3 dimensional space filling Peano curve while the user is tracking it with their eyes. This results in a fully automated calibration procedure that yields several thousand calibration points versus standard approaches using a dozen points, resulting in beyond state-of-the-art 3D accuracy and precision.

Correspondence of presaccadic activity in the monkey primary visual cortex with saccadic eye movements

PubMed Central

Supèr, Hans; van der Togt, Chris; Spekreijse, Henk; Lamme, Victor A. F.

2004-01-01

We continuously scan the visual world via rapid or saccadic eye movements. Such eye movements are guided by visual information, and thus the oculomotor structures that determine when and where to look need visual information to control the eye movements. To know whether visual areas contain activity that may contribute to the control of eye movements, we recorded neural responses in the visual cortex of monkeys engaged in a delayed figure-ground detection task and analyzed the activity during the period of oculomotor preparation. We show that ≈100 ms before the onset of visually and memory-guided saccades neural activity in V1 becomes stronger where the strongest presaccadic responses are found at the location of the saccade target. In addition, in memory-guided saccades the strength of presaccadic activity shows a correlation with the onset of the saccade. These findings indicate that the primary visual cortex contains saccade-related responses and participates in visually guided oculomotor behavior. PMID:14970334

The selective disruption of spatial working memory by eye movements

PubMed Central

Postle, Bradley R.; Idzikowski, Christopher; Sala, Sergio Della; Logie, Robert H.; Baddeley, Alan D.

2005-01-01

In the late 1970s/early 1980s, Baddeley and colleagues conducted a series of experiments investigating the role of eye movements in visual working memory. Although only described briefly in a book (Baddeley, 1986), these studies have influenced a remarkable number of empirical and theoretical developments in fields ranging from experimental psychology to human neuropsychology to nonhuman primate electrophysiology. This paper presents, in full detail, three critical studies from this series, together with a recently performed study that includes a level of eye movement measurement and control that was not available for the older studies. Together, the results demonstrate several facts about the sensitivity of visuospatial working memory to eye movements. First, it is eye movement control, not movement per se, that produces the disruptive effects. Second, these effects are limited to working memory for locations, and do not generalize to visual working memory for shapes. Third, they can be isolated to the storage/maintenance components of working memory (e.g., to the delay period of the delayed-recognition task). These facts have important implications for models of visual working memory. PMID:16556561

Visual processing and social cognition in schizophrenia: relationships among eye movements, biological motion perception, and empathy.

PubMed

Matsumoto, Yukiko; Takahashi, Hideyuki; Murai, Toshiya; Takahashi, Hidehiko

2015-01-01

Schizophrenia patients have impairments at several levels of cognition including visual attention (eye movements), perception, and social cognition. However, it remains unclear how lower-level cognitive deficits influence higher-level cognition. To elucidate the hierarchical path linking deficient cognitions, we focused on biological motion perception, which is involved in both the early stage of visual perception (attention) and higher social cognition, and is impaired in schizophrenia. Seventeen schizophrenia patients and 18 healthy controls participated in the study. Using point-light walker stimuli, we examined eye movements during biological motion perception in schizophrenia. We assessed relationships among eye movements, biological motion perception and empathy. In the biological motion detection task, schizophrenia patients showed lower accuracy and fixated longer than healthy controls. As opposed to controls, patients exhibiting longer fixation durations and fewer numbers of fixations demonstrated higher accuracy. Additionally, in the patient group, the correlations between accuracy and affective empathy index and between eye movement index and affective empathy index were significant. The altered gaze patterns in patients indicate that top-down attention compensates for impaired bottom-up attention. Furthermore, aberrant eye movements might lead to deficits in biological motion perception and finally link to social cognitive impairments. The current findings merit further investigation for understanding the mechanism of social cognitive training and its development. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Head eye co-ordination and gaze stability in subjects with persistent whiplash associated disorders.

PubMed

Treleaven, Julia; Jull, Gwendolen; Grip, Helena

2011-06-01

Symptoms of dizziness, unsteadiness and visual disturbances are frequent complaints in persons with persistent whiplash associated disorders. This study investigated eye, head co-ordination and gaze stability in subjects with persistent whiplash (n = 20) and asymptomatic controls (n = 20). Wireless motion sensors and electro-oculography were used to measure: head rotation during unconstrained head movement, head rotation during gaze stability and sequential head and eye movements. Ten control subjects participated in a repeatability study (two occasions one week apart). Between-day repeatability was acceptable (ICC > 0.6) for most measures. The whiplash group had significantly less maximal eye angle to the left, range of head movement during the gaze stability task and decreased velocity of head movement in head eye co-ordination and gaze stability tasks compared to the control group (p < 0.01). There were significant correlations (r > 0.55) between both unrestrained neck movement and neck pain and head movement and velocity in the whiplash group. Deficits in gaze stability and head eye co-ordination may be related to disturbed reflex activity associated with decreased head range of motion and/or neck pain. Further research is required to explore the mechanisms behind these deficits, the nature of changes over time and the tests' ability to measure change in response to rehabilitation. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

MR-eyetracker: a new method for eye movement recording in functional magnetic resonance imaging.

PubMed

Kimmig, H; Greenlee, M W; Huethe, F; Mergner, T

1999-06-01

We present a method for recording saccadic and pursuit eye movements in the magnetic resonance tomograph designed for visual functional magnetic resonance imaging (fMRI) experiments. To reliably classify brain areas as pursuit or saccade related it is important to carefully measure the actual eye movements. For this purpose, infrared light, created outside the scanner by light-emitting diodes (LEDs), is guided via optic fibers into the head coil and onto the eye of the subject. Two additional fiber optical cables pick up the light reflected by the iris. The illuminating and detecting cables are mounted in a plastic eyepiece that is manually lowered to the level of the eye. By means of differential amplification, we obtain a signal that covaries with the horizontal position of the eye. Calibration of eye position within the scanner yields an estimate of eye position with a resolution of 0.2 degrees at a sampling rate of 1000 Hz. Experiments are presented that employ echoplanar imaging with 12 image planes through visual, parietal and frontal cortex while subjects performed saccadic and pursuit eye movements. The distribution of BOLD (blood oxygen level dependent) responses is shown to depend on the type of eye movement performed. Our method yields high temporal and spatial resolution of the horizontal component of eye movements during fMRI scanning. Since the signal is purely optical, there is no interaction between the eye movement signals and the echoplanar images. This reasonably priced eye tracker can be used to control eye position and monitor eye movements during fMRI.

Cognitive Control of Saccadic Eye Movements

ERIC Educational Resources Information Center

Hutton, S. B.

2008-01-01

The saccadic eye movement system provides researchers with a powerful tool with which to explore the cognitive control of behaviour. It is a behavioural system whose limited output can be measured with exceptional precision, and whose input can be controlled and manipulated in subtle ways. A range of cognitive processes (notably those involved in…

Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

NASA Technical Reports Server (NTRS)

Bendrick, Gregg A.; Kamine, Tovy Haber

2008-01-01

Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.

Electroencephalographic prodromal markers of dementia across conscious states in Parkinson’s disease

PubMed Central

Latreille, Véronique; Gaudet-Fex, Benjamin; Rodrigues-Brazète, Jessica; Panisset, Michel; Chouinard, Sylvain; Postuma, Ronald B.

2016-01-01

Abstract In Parkinson’s disease, electroencephalographic abnormalities during wakefulness and non-rapid eye movement sleep (spindles) were found to be predictive biomarkers of dementia. Because rapid eye movement sleep is regulated by the cholinergic system, which shows early degeneration in Parkinson’s disease with cognitive impairment, anomalies during this sleep stage might mirror dementia development. In this prospective study, we examined baseline electroencephalographic absolute spectral power across three states of consciousness (non-rapid eye movement sleep, rapid eye movement sleep, and wakefulness) in 68 non-demented patients with Parkinson’s disease and 44 healthy controls. All participants underwent baseline polysomnographic recordings and a comprehensive neuropsychological assessment. Power spectral analyses were performed on standard frequency bands. Dominant occipital frequency during wakefulness and ratios of slow-to-fast frequencies during rapid eye movement sleep and wakefulness were also computed. At follow-up (an average 4.5 years after baseline), 18 patients with Parkinson’s disease had developed dementia and 50 patients remained dementia-free. In rapid eye movement sleep, patients with Parkinson’s disease who later developed dementia showed, at baseline, higher absolute power in delta and theta bands and a higher slowing ratio, especially in temporal, parietal, and occipital regions, compared to patients who remained dementia-free and controls. In non-rapid eye movement sleep, lower baseline sigma power in parietal cortical regions also predicted development of dementia. During wakefulness, patients with Parkinson’s disease who later developed dementia showed lower dominant occipital frequency as well as higher delta and slowing ratio compared to patients who remained dementia-free and controls. At baseline, higher slowing ratios in temporo-occipital regions during rapid eye movement sleep were associated with poor performance on visuospatial tests in patients with Parkinson’s disease. Using receiver operating characteristic curves, we found that best predictors of dementia in Parkinson’s disease were rapid eye movement sleep slowing ratios in posterior regions, wakefulness slowing ratios in temporal areas, and lower dominant occipital frequency. These results suggest that electroencephalographic slowing during sleep is a new promising predictive biomarker for Parkinson’s disease dementia, perhaps as a marker of cholinergic denervation. PMID:26912643

Kinematics and eye-head coordination of gaze shifts evoked from different sites in the superior colliculus of the cat.

PubMed

Guillaume, Alain; Pélisson, Denis

2006-12-15

Shifting gaze requires precise coordination of eye and head movements. It is clear that the superior colliculus (SC) is involved with saccadic gaze shifts. Here we investigate its role in controlling both eye and head movements during gaze shifts. Gaze shifts of the same amplitude can be evoked from different SC sites by controlled electrical microstimulation. To describe how the SC coordinates the eye and the head, we compare the characteristics of these amplitude-matched gaze shifts evoked from different SC sites. We show that matched amplitude gaze shifts elicited from progressively more caudal sites are progressively slower and associated with a greater head contribution. Stimulation at more caudal SC sites decreased the peak velocity of the eye but not of the head, suggesting that the lower peak gaze velocity for the caudal sites is due to the increased contribution of the slower-moving head. Eye-head coordination across the SC motor map is also indicated by the relative latencies of the eye and head movements. For some amplitudes of gaze shift, rostral stimulation evoked eye movement before head movement, whereas this reversed with caudal stimulation, which caused the head to move before the eyes. These results show that gaze shifts of similar amplitude evoked from different SC sites are produced with different kinematics and coordination of eye and head movements. In other words, gaze shifts evoked from different SC sites follow different amplitude-velocity curves, with different eye-head contributions. These findings shed light on mechanisms used by the central nervous system to translate a high-level motor representation (a desired gaze displacement on the SC map) into motor commands appropriate for the involved body segments (the eye and the head).

Diagnostic accuracy of eye movements in assessing pedophilia.

PubMed

Fromberger, Peter; Jordan, Kirsten; Steinkrauss, Henrike; von Herder, Jakob; Witzel, Joachim; Stolpmann, Georg; Kröner-Herwig, Birgit; Müller, Jürgen Leo

2012-07-01

Given that recurrent sexual interest in prepubescent children is one of the strongest single predictors for pedosexual offense recidivism, valid and reliable diagnosis of pedophilia is of particular importance. Nevertheless, current assessment methods still fail to fulfill psychometric quality criteria. The aim of the study was to evaluate the diagnostic accuracy of eye-movement parameters in regard to pedophilic sexual preferences. Eye movements were measured while 22 pedophiles (according to ICD-10 F65.4 diagnosis), 8 non-pedophilic forensic controls, and 52 healthy controls simultaneously viewed the picture of a child and the picture of an adult. Fixation latency was assessed as a parameter for automatic attentional processes and relative fixation time to account for controlled attentional processes. Receiver operating characteristic (ROC) analyses, which are based on calculated age-preference indices, were carried out to determine the classifier performance. Cross-validation using the leave-one-out method was used to test the validity of classifiers. Pedophiles showed significantly shorter fixation latencies and significantly longer relative fixation times for child stimuli than either of the control groups. Classifier performance analysis revealed an area under the curve (AUC) = 0.902 for fixation latency and an AUC = 0.828 for relative fixation time. The eye-tracking method based on fixation latency discriminated between pedophiles and non-pedophiles with a sensitivity of 86.4% and a specificity of 90.0%. Cross-validation demonstrated good validity of eye-movement parameters. Despite some methodological limitations, measuring eye movements seems to be a promising approach to assess deviant pedophilic interests. Eye movements, which represent automatic attentional processes, demonstrated high diagnostic accuracy. © 2012 International Society for Sexual Medicine.

Evaluation of an eye-pointer interaction device for human-computer interaction.

PubMed

Cáceres, Enrique; Carrasco, Miguel; Ríos, Sebastián

2018-03-01

Advances in eye-tracking technology have led to better human-computer interaction, and involve controlling a computer without any kind of physical contact. This research describes the transformation of a commercial eye-tracker for use as an alternative peripheral device in human-computer interactions, implementing a pointer that only needs the eye movements of a user facing a computer screen, thus replacing the need to control the software by hand movements. The experiment was performed with 30 test individuals who used the prototype with a set of educational videogames. The results show that, although most of the test subjects would prefer a mouse to control the pointer, the prototype tested has an empirical precision similar to that of the mouse, either when trying to control its movements or when attempting to click on a point of the screen.

Initial component control in disparity vergence: a model-based study.

PubMed

Horng, J L; Semmlow, J L; Hung, G K; Ciuffreda, K J

1998-02-01

The dual-mode theory for the control of disparity-vergence eye movements states that two components control the response to a step change in disparity. The initial component uses a motor preprogram to drive the eyes to an approximate final position. This initial component is followed by activation of a late component operating under visual feedback control that reduces residual disparity to within fusional limits. A quantitative model based on a pulse-step controller, similar to that postulated for saccadic eye movements, has been developed to represent the initial component. This model, an adaptation of one developed by Zee et al. [1], provides accurate simulations of isolated initial component movements and is compatible with the known underlying neurophysiology and existing neurophysiological data. The model has been employed to investigate the difference in dynamics between convergent and divergent movements. Results indicate that the pulse-control component active in convergence is reduced or absent from the control signals of divergence movements. This suggests somewhat different control structures of convergence versus divergence, and is consistent with other directional asymmetries seen in horizontal vergence.

Do Learning-Disabled Children Exhibit Peripheral Deficits in Selective Attention? An Analysis of Eye Movements during Reading.

ERIC Educational Resources Information Center

Lahey, Benjamin B.; And Others

1982-01-01

The learning disabled children did not differ from their reading level controls on any of 10 measures but showed a pattern of eye movements that was generally slower and less smooth than their grade placement controls. (Author)

Oculomotor Apraxia

MedlinePlus

... a defect in, the control of voluntary purposeful eye movement. Children with this condition have difficulty moving their ... to compensate for this inability to initiate horizontal eye movements away from the straight-ahead gaze position. Typically, ...

Word processing during reading sentences in patients with schizophrenia: evidences from the eyetracking technique.

PubMed

Fernández, Gerardo; Sapognikoff, Marcelo; Guinjoan, Salvador; Orozco, David; Agamennoni, Osvaldo

2016-07-01

The current study analyze the effect of word properties (i.e., word length, word frequency and word predictability) on the eye movement behavior of patients with schizophrenia (SZ) compared to age-matched controls. 18 SZ patients and 40 age matched controls participated in the study. Eye movements were recorded during reading regular sentences by using the eyetracking technique. Eye movement analyses were performed using linear mixed models. Analysis of eye movements revealed that patients with SZ decreased the amount of single fixations, increased their total number of second pass fixations compared with healthy individuals (Controls). In addition, SZ patients showed an increase in gaze duration, compared to Controls. Interestingly, the effects of current word frequency and current word length processing were similar in Controls and SZ patients. The high rate of second pass fixations and its low rate in single fixation might reveal impairments in working memory when integrating neighbor words. In contrast, word frequency and length processing might require less complex mechanisms, which were functioning in SZ patients. To the best of our knowledge, this is the first study measuring how patients with SZ process dynamically well-defined words embedded in regular sentences. The findings suggest that evaluation of the resulting changes in eye movement behavior may supplement current symptom-based diagnosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Variability of eye movements when viewing dynamic natural scenes.

PubMed

Dorr, Michael; Martinetz, Thomas; Gegenfurtner, Karl R; Barth, Erhardt

2010-08-26

How similar are the eye movement patterns of different subjects when free viewing dynamic natural scenes? We collected a large database of eye movements from 54 subjects on 18 high-resolution videos of outdoor scenes and measured their variability using the Normalized Scanpath Saliency, which we extended to the temporal domain. Even though up to about 80% of subjects looked at the same image region in some video parts, variability usually was much greater. Eye movements on natural movies were then compared with eye movements in several control conditions. "Stop-motion" movies had almost identical semantic content as the original videos but lacked continuous motion. Hollywood action movie trailers were used to probe the upper limit of eye movement coherence that can be achieved by deliberate camera work, scene cuts, etc. In a "repetitive" condition, subjects viewed the same movies ten times each over the course of 2 days. Results show several systematic differences between conditions both for general eye movement parameters such as saccade amplitude and fixation duration and for eye movement variability. Most importantly, eye movements on static images are initially driven by stimulus onset effects and later, more so than on continuous videos, by subject-specific idiosyncrasies; eye movements on Hollywood movies are significantly more coherent than those on natural movies. We conclude that the stimuli types often used in laboratory experiments, static images and professionally cut material, are not very representative of natural viewing behavior. All stimuli and gaze data are publicly available at http://www.inb.uni-luebeck.de/tools-demos/gaze.

Volitional control of anticipatory ocular pursuit responses under stabilised image conditions in humans.

PubMed

Barnes, G; Goodbody, S; Collins, S

1995-01-01

Ocular pursuit responses have been examined in humans in three experiments in which the pursuit target image has been fully or partially stabilised on the fovea by feeding a recorded eye movement signal back to drive the target motion. The objective was to establish whether subjects could volitionally control smooth eye movement to reproduce trajectories of target motion in the absence of a concurrent target motion stimulus. In experiment 1 subjects were presented with a target moving with a triangular waveform in the horizontal axis with a frequency of 0.325 Hz and velocities of +/- 10-50 degrees/s. The target was illuminated twice per cycle for pulse durations (PD) of 160-640 ms as it passed through the centre position; otherwise subjects were in darkness. Subjects initially tracked the target motion in a conventional closed-loop mode for four cycles. Prior to the next target presentation the target image was stabilised on the fovea, so that any target motion generated resulted solely from volitional eye movement. Subjects continued to make anticipatory smooth eye movements both to the left and the right with a velocity trajectory similar to that observed in the closed-loop phase. Peak velocity in the stabilised-image mode was highly correlated with that in the prior closed-loop phase, but was slightly less (84% on average). In experiment 2 subjects were presented with a continuously illuminated target that was oscillated sinusoidally at frequencies of 0.2-1.34 Hz and amplitudes of +/- 5-20 degrees. After four cycles of closed-loop stimulation the image was stabilised on the fovea at the time of peak target displacement. Subjects continued to generate an oscillatory smooth eye velocity pattern that mimicked the sinusoidal motion of the previous closed-loop phase for at least three further cycles. The peak eye velocity generated ranged from 57-95% of that in the closed-loop phase at frequencies up to 0.8 Hz but decreased significantly at 1.34 Hz. In experiment 3 subjects were presented with a stabilised display throughout and generated smooth eye movements with peak velocity up to 84 degrees/s in the complete absence of any prior external target motion stimulus, by transferring their attention alternately to left and right of the centre of the display. Eye velocity was found to be dependent on the eccentricity of the centre of attention and the frequency of alternation. When the target was partially stabilised on the retina by feeding back only a proportion (Kf = 0.6-0.9) of the eye movement signal to drive the target, subjects were still able to generate smooth movements at will, even though the display did not move as far or as fast as the eye. Peak eye velocity decreased as Kf decreased, suggesting that there was a continuous competitive interaction between the volitional drive and the visual feedback provided by the relative motion of the display with respect to the retina. These results support the evidence for two separate mechanisms of smooth eye movement control in ocular pursuit: reflex control from retinal velocity error feedback and volitional control from an internal source. Arguments are presented to indicate how smooth pursuit may be controlled by matching a voluntarily initiated estimate of the required smooth movement, normally derived from storage of past re-afferent information, against current visual feedback information. Such a mechanism allows preemptive smooth eye movements to be made that can overcome the inherent delays in the visual feedback pathway.

Machado-Joseph Disease

MedlinePlus

... for drunkenness, difficulty with speech and swallowing, involuntary eye movements, double vision, and frequent urination. Some individuals also ... color and/or contrast, and inability to control eye movements. × Definition Machado-Joseph disease (MJD), which is also ...

Smooth pursuitlike eye movements evoked by microstimulation in macaque nucleus reticularis tegmenti pontis.

PubMed

Yamada, T; Suzuki, D A; Yee, R D

1996-11-01

1. Smooth pursuitlike eye movements were evoked with low current microstimulation delivered to rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. Microstimulation sites were selected by the observation of modulations in single-cell firing rates that were correlated with periodic smoothpursuit eye movements. Current intensities ranged from 10 to 120 microA and were routinely < 40 microA. Microstimulation was delivered either in the dark with no fixation, 100 ms after a fixation target was extinguished, or during maintained fixation of a stationary or moving target. Evoked eye movements also were studied under open-loop conditions with the target image stabilized on the retina. 2. Eye movements evoked in the absence of a target rapidly accelerated to a constant velocity that was maintained for the duration of the microstimulation. Evoked eye speeds ranged from 3.7 to 23 deg/s and averaged 11 deg/s. Evoked eye speed appeared to be linearly related to initial eye position with a sensitivity to initial eye position that averaged 0.23 deg.s-1.deg-1. While some horizontal and oblique smooth eye movements were elicited, microstimulation resulted in upward eye movements in 89% of the sites. 3. Evoked eye speed was found to be dependent on microstimulation pulse frequency and current intensity. Within limits, evoked eye speed increased with increases in stimulation frequency or current intensity. For stimulation frequencies < 300-400 Hz, only smooth pursuit-like eye movements were evoked. At higher stimulation frequencies, accompanying saccades consistently were elicited. 4. Feedback of retinal image motion interacted with the evoked eye movements to decrease eye speed if the visual motion was in the opposite direction as the evoked, pursuit-like eye movements. 5. The results implicate rNRTP as part of the neuronal substrate that controls smooth-pursuit eye movements. NRTP appears to be divided functionally into a rostral, pursuit-related portion and a caudal, saccade-related area. rNRTP is a component of a corticopontocerebellar circuit that presumably involves the pursuit area of the frontal eye field and that parallels the middle and medial superior temporal cerebral cortical/dorsalateral pontine nucleus (MT/MST-DLPN-cerebellum) pathway known to be involved also with regulating smooth-pursuit eye movements.

GOM-Face: GKP, EOG, and EMG-based multimodal interface with application to humanoid robot control.

PubMed

Nam, Yunjun; Koo, Bonkon; Cichocki, Andrzej; Choi, Seungjin

2014-02-01

We present a novel human-machine interface, called GOM-Face , and its application to humanoid robot control. The GOM-Face bases its interfacing on three electric potentials measured on the face: 1) glossokinetic potential (GKP), which involves the tongue movement; 2) electrooculogram (EOG), which involves the eye movement; 3) electromyogram, which involves the teeth clenching. Each potential has been individually used for assistive interfacing to provide persons with limb motor disabilities or even complete quadriplegia an alternative communication channel. However, to the best of our knowledge, GOM-Face is the first interface that exploits all these potentials together. We resolved the interference between GKP and EOG by extracting discriminative features from two covariance matrices: a tongue-movement-only data matrix and eye-movement-only data matrix. With the feature extraction method, GOM-Face can detect four kinds of horizontal tongue or eye movements with an accuracy of 86.7% within 2.77 s. We demonstrated the applicability of the GOM-Face to humanoid robot control: users were able to communicate with the robot by selecting from a predefined menu using the eye and tongue movements.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson's disease.

PubMed

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C; Mackay, Clare E; Hu, Michele T M

2016-08-01

SEE POSTUMA DOI101093/AWW131 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson's disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson's disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson's disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson's disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson's disease and 10 control subjects received (123)I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson's disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson's disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson's disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson's disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson's disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson’s disease

PubMed Central

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A.; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A.; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C.; Mackay, Clare E.

2016-01-01

Abstract See Postuma (doi:10.1093/aww131) for a scientific commentary on this article. Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson’s disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson’s disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson’s disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson’s disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson’s disease and 10 control subjects received 123I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson’s disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson’s disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson’s disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson’s disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson’s disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. PMID:27297241

Genetics Home Reference: CASK-related intellectual disability

MedlinePlus

... XL-ID with or without nystagmus (rapid, involuntary eye movements) is a milder form of CASK -related intellectual ... to promote development of the nerves that control eye movement (the oculomotor neural network). Mutations in the CASK ...

Human-Computer Interface Controlled by Horizontal Directional Eye Movements and Voluntary Blinks Using AC EOG Signals

NASA Astrophysics Data System (ADS)

Kajiwara, Yusuke; Murata, Hiroaki; Kimura, Haruhiko; Abe, Koji

As a communication support tool for cases of amyotrophic lateral sclerosis (ALS), researches on eye gaze human-computer interfaces have been active. However, since voluntary and involuntary eye movements cannot be distinguished in the interfaces, their performance is still not sufficient for practical use. This paper presents a high performance human-computer interface system which unites high quality recognitions of horizontal directional eye movements and voluntary blinks. The experimental results have shown that the number of incorrect inputs is decreased by 35.1% in an existing system which equips recognitions of horizontal and vertical directional eye movements in addition to voluntary blinks and character inputs are speeded up by 17.4% from the existing system.

Eye movements during object recognition in visual agnosia.

PubMed

Charles Leek, E; Patterson, Candy; Paul, Matthew A; Rafal, Robert; Cristino, Filipe

2012-07-01

This paper reports the first ever detailed study about eye movement patterns during single object recognition in visual agnosia. Eye movements were recorded in a patient with an integrative agnosic deficit during two recognition tasks: common object naming and novel object recognition memory. The patient showed normal directional biases in saccades and fixation dwell times in both tasks and was as likely as controls to fixate within object bounding contour regardless of recognition accuracy. In contrast, following initial saccades of similar amplitude to controls, the patient showed a bias for short saccades. In object naming, but not in recognition memory, the similarity of the spatial distributions of patient and control fixations was modulated by recognition accuracy. The study provides new evidence about how eye movements can be used to elucidate the functional impairments underlying object recognition deficits. We argue that the results reflect a breakdown in normal functional processes involved in the integration of shape information across object structure during the visual perception of shape. Copyright © 2012 Elsevier Ltd. All rights reserved.

Research to Improve Emotional Health and Quality of Life Among Service Members with Disabilities (RESTORE LIVES)

DTIC Science & Technology

2012-10-01

and Eye Movement Desensitization and Reprocessing ( EMDR ) which lead to clinically improved outcomes in...that uses eye movements and is designed to be brief (i.e. 1-5 treatment sessions). • By use of a randomized controlled trial, to evaluate ART versus...as to specific therapeutic role of eye movements , and 3-month follow-up results (sustainability) are pending. • Given short treatment duration

The role of eye movements in decision making and the prospect of exposure effects.

PubMed

Bird, Gary D; Lauwereyns, Johan; Crawford, Matthew T

2012-05-01

The aim of the current study was to follow on from previous findings that eye movements can have a causal influence on preference formation. Shimojo et al. (2003) previously found that faces that were presented for a longer duration in a two alternative forced choice task were more likely to be judged as more attractive. This effect only occurred when an eye movement was made towards the faces (with no effect when faces were centrally presented). The current study replicated Shimojo et al.'s (2003) design, whilst controlling for potential inter-stimuli interference in central presentations. As per previous findings, when eye movements were made towards the stimuli, faces that were presented for longer durations were preferred. However, faces that were centrally presented (thus not requiring an eye movement) were also preferred in the current study. The presence of an exposure duration effect for centrally presented faces casts doubt on the necessity of the eye movement in this decision making process and has implications for decision theories that place an emphasis on the role of eye movements in decision making. Copyright © 2012 Elsevier Ltd. All rights reserved.

Space flight and neurovestibular adaptation

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Bloomberg, J. J.; Harm, D. L.; Paloski, W. H.

1994-01-01

Space flight represents a form of sensory stimulus rearrangement requiring modification of established terrestrial response patterns through central reinterpretation. Evidence of sensory reinterpretation is manifested as postflight modifications of eye/head coordination, locomotor patterns, postural control strategies, and illusory perceptions of self or surround motion in conjunction with head movements. Under normal preflight conditions, the head is stabilized during locomotion, but immediately postflight reduced head stability, coupled with inappropriate eye/head coordination, results in modifications of gait. Postflight postural control exhibits increased dependence on vision which compensates for inappropriate interpretation of otolith and proprioceptive inputs. Eye movements compensatory for perceived self motion, rather than actual head movements have been observed postflight. Overall, the in-flight adaptive modification of head stabilization strategies, changes in head/eye coordination, illusionary motion, and postural control are maladaptive for a return to the terrestrial environment.

Eye Velocity Gain Fields in MSTd During Optokinetic Stimulation

PubMed Central

Brostek, Lukas; Büttner, Ulrich; Mustari, Michael J.; Glasauer, Stefan

2015-01-01

Lesion studies argue for an involvement of cortical area dorsal medial superior temporal area (MSTd) in the control of optokinetic response (OKR) eye movements to planar visual stimulation. Neural recordings during OKR suggested that MSTd neurons directly encode stimulus velocity. On the other hand, studies using radial visual flow together with voluntary smooth pursuit eye movements showed that visual motion responses were modulated by eye movement-related signals. Here, we investigated neural responses in MSTd during continuous optokinetic stimulation using an information-theoretic approach for characterizing neural tuning with high resolution. We show that the majority of MSTd neurons exhibit gain-field-like tuning functions rather than directly encoding one variable. Neural responses showed a large diversity of tuning to combinations of retinal and extraretinal input. Eye velocity-related activity was observed prior to the actual eye movements, reflecting an efference copy. The observed tuning functions resembled those emerging in a network model trained to perform summation of 2 population-coded signals. Together, our findings support the hypothesis that MSTd implements the visuomotor transformation from retinal to head-centered stimulus velocity signals for the control of OKR. PMID:24557636

I can read it in your eyes: what eye movements tell us about visuo-attentional processes in developmental dyslexia.

PubMed

Bellocchi, Stéphanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stéphanie

2013-01-01

Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body of research has found evidence of defective visuo-attentional processes in dyslexics. What do eye movements tell us about visuo-attentional deficits in developmental dyslexia? The purpose of this paper is to explore the link between oculomotor control and dyslexia, taking into account its heterogeneous manifestation and comorbidity. Clinical perspectives in the use of the eye-movements approach to better explore and understand reading impairments are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

An Anatomically Constrained, Stochastic Model of Eye Movement Control in Reading

ERIC Educational Resources Information Center

McDonald, Scott A.; Carpenter, R. H. S.; Shillcock, Richard C.

2005-01-01

This article presents SERIF, a new model of eye movement control in reading that integrates an established stochastic model of saccade latencies (LATER; R. H. S. Carpenter, 1981) with a fundamental anatomical constraint on reading: the vertically split fovea and the initial projection of information in either visual field to the contralateral…

Eye movements reveal sexually dimorphic deficits in children with fetal alcohol spectrum disorder

PubMed Central

Paolozza, Angelina; Munn, Rebecca; Munoz, Douglas P.; Reynolds, James N.

2015-01-01

Background: We examined the accuracy and characteristics of saccadic eye movements in children with fetal alcohol spectrum disorder (FASD) compared with typically developing control children. Previous studies have found that children with FASD produce saccades that are quantifiably different from controls. Additionally, animal studies have found sex-based differences for behavioral effects after prenatal alcohol exposure. Therefore, we hypothesized that eye movement measures will show sexually dimorphic results. Methods: Children (aged 5–18 years) with FASD (n = 71) and typically developing controls (n = 113) performed a visually-guided saccade task. Saccade metrics and behavior were analyzed for sex and group differences. Results: Female control participants had greater amplitude saccades than control males or females with FASD. Accuracy was significantly poorer in the FASD group, especially in males, which introduced significantly greater variability in the data. Therefore, we conducted additional analyses including only those trials in which the first saccade successfully reached the target within a ± 1° window. In this restricted amplitude dataset, the females with FASD made saccades with significantly lower velocity and longer duration, whereas the males with FASD did not differ from the control group. Additionally, the mean and peak deceleration were selectively decreased in the females with FASD. Conclusions: These data support the hypothesis that children with FASD exhibit specific deficits in eye movement control and sensory-motor integration associated with cerebellar and/or brain stem circuits. Moreover, prenatal alcohol exposure may have a sexually dimorphic impact on eye movement metrics, with males and females exhibiting differential patterns of deficit. PMID:25814922

The control of voluntary eye movements: new perspectives.

PubMed

Krauzlis, Richard J

2005-04-01

Primates use two types of voluntary eye movements to track objects of interest: pursuit and saccades. Traditionally, these two eye movements have been viewed as distinct systems that are driven automatically by low-level visual inputs. However, two sets of findings argue for a new perspective on the control of voluntary eye movements. First, recent experiments have shown that pursuit and saccades are not controlled by entirely different neural pathways but are controlled by similar networks of cortical and subcortical regions and, in some cases, by the same neurons. Second, pursuit and saccades are not automatic responses to retinal inputs but are regulated by a process of target selection that involves a basic form of decision making. The selection process itself is guided by a variety of complex processes, including attention, perception, memory, and expectation. Together, these findings indicate that pursuit and saccades share a similar functional architecture. These points of similarity may hold the key for understanding how neural circuits negotiate the links between the many higher order functions that can influence behavior and the singular and coordinated motor actions that follow.

A novel EOG/EEG hybrid human-machine interface adopting eye movements and ERPs: application to robot control.

PubMed

Ma, Jiaxin; Zhang, Yu; Cichocki, Andrzej; Matsuno, Fumitoshi

2015-03-01

This study presents a novel human-machine interface (HMI) based on both electrooculography (EOG) and electroencephalography (EEG). This hybrid interface works in two modes: an EOG mode recognizes eye movements such as blinks, and an EEG mode detects event related potentials (ERPs) like P300. While both eye movements and ERPs have been separately used for implementing assistive interfaces, which help patients with motor disabilities in performing daily tasks, the proposed hybrid interface integrates them together. In this way, both the eye movements and ERPs complement each other. Therefore, it can provide a better efficiency and a wider scope of application. In this study, we design a threshold algorithm that can recognize four kinds of eye movements including blink, wink, gaze, and frown. In addition, an oddball paradigm with stimuli of inverted faces is used to evoke multiple ERP components including P300, N170, and VPP. To verify the effectiveness of the proposed system, two different online experiments are carried out. One is to control a multifunctional humanoid robot, and the other is to control four mobile robots. In both experiments, the subjects can complete tasks effectively by using the proposed interface, whereas the best completion time is relatively short and very close to the one operated by hand.

Observers' cognitive states modulate how visual inputs relate to gaze control.

PubMed

Kardan, Omid; Henderson, John M; Yourganov, Grigori; Berman, Marc G

2016-09-01

Previous research has shown that eye-movements change depending on both the visual features of our environment, and the viewer's top-down knowledge. One important question that is unclear is the degree to which the visual goals of the viewer modulate how visual features of scenes guide eye-movements. Here, we propose a systematic framework to investigate this question. In our study, participants performed 3 different visual tasks on 135 scenes: search, memorization, and aesthetic judgment, while their eye-movements were tracked. Canonical correlation analyses showed that eye-movements were reliably more related to low-level visual features at fixations during the visual search task compared to the aesthetic judgment and scene memorization tasks. Different visual features also had different relevance to eye-movements between tasks. This modulation of the relationship between visual features and eye-movements by task was also demonstrated with classification analyses, where classifiers were trained to predict the viewing task based on eye movements and visual features at fixations. Feature loadings showed that the visual features at fixations could signal task differences independent of temporal and spatial properties of eye-movements. When classifying across participants, edge density and saliency at fixations were as important as eye-movements in the successful prediction of task, with entropy and hue also being significant, but with smaller effect sizes. When classifying within participants, brightness and saturation were also significant contributors. Canonical correlation and classification results, together with a test of moderation versus mediation, suggest that the cognitive state of the observer moderates the relationship between stimulus-driven visual features and eye-movements. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Saccade-related activity in the prefrontal cortex: its role in eye movement control and cognitive functions

PubMed Central

Funahashi, Shintaro

2014-01-01

Prefrontal neurons exhibit saccade-related activity and pre-saccadic memory-related activity often encodes the directions of forthcoming eye movements, in line with demonstrated prefrontal contribution to flexible control of voluntary eye movements. However, many prefrontal neurons exhibit post-saccadic activity that is initiated well after the initiation of eye movement. Although post-saccadic activity has been observed in the frontal eye field, this activity is thought to be a corollary discharge from oculomotor centers, because this activity shows no directional tuning and is observed whenever the monkeys perform eye movements regardless of goal-directed or not. However, prefrontal post-saccadic activities exhibit directional tunings similar as pre-saccadic activities and show context dependency, such that post-saccadic activity is observed only when monkeys perform goal-directed saccades. Context-dependency of prefrontal post-saccadic activity suggests that this activity is not a result of corollary signals from oculomotor centers, but contributes to other functions of the prefrontal cortex. One function might be the termination of memory-related activity after a behavioral response is done. This is supported by the observation that the termination of memory-related activity coincides with the initiation of post-saccadic activity in population analyses of prefrontal activities. The termination of memory-related activity at the end of the trial ensures that the subjects can prepare to receive new and updated information. Another function might be the monitoring of behavioral performance, since the termination of memory-related activity by post-saccadic activity could be associated with informing the correctness of the response and the termination of the trial. However, further studies are needed to examine the characteristics of saccade-related activities in the prefrontal cortex and their functions in eye movement control and a variety of cognitive functions. PMID:25071482

Eye movements in patients with schizophrenia: visual stimuli, semantic content and psychiatric symptoms.

PubMed

Ishizuka, K; Kashiwakura, M; Oiji, A

1998-05-01

In order to explore a possible association between psychiatric symptoms and eye movements, 32 patients with schizophrenia were examined using an eye mark recorder in combination with the Positive and Negative Syndrome Scale, and were compared with 32 controls. Four types of figures were presented to the subjects: geometrical figures, drawings, story drawings, and sentences. Mean eye fixation time was significantly longer and mean eye scanning length was significantly shorter for the patients than for controls, not only in response to the geometric figures, but also in response to the story drawings. Eye fixation time and scanning velocity were positively correlated with degrees of thought disturbance. The number of eye fixations, eye fixation time and scanning velocity were negatively correlated with degree of depressive tendency.

Abnormal Fixational Eye Movements in Amblyopia.

PubMed

Shaikh, Aasef G; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F

2016-01-01

Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity.

Abnormal Fixational Eye Movements in Amblyopia

PubMed Central

Shaikh, Aasef G.; Otero-Millan, Jorge; Kumar, Priyanka; Ghasia, Fatema F.

2016-01-01

Purpose Fixational saccades shift the foveal image to counteract visual fading related to neural adaptation. Drifts are slow eye movements between two adjacent fixational saccades. We quantified fixational saccades and asked whether their changes could be attributed to pathologic drifts seen in amblyopia, one of the most common causes of blindness in childhood. Methods Thirty-six pediatric subjects with varying severity of amblyopia and eleven healthy age-matched controls held their gaze on a visual target. Eye movements were measured with high-resolution video-oculography during fellow eye-viewing and amblyopic eye-viewing conditions. Fixational saccades and drifts were analyzed in the amblyopic and fellow eye and compared with controls. Results We found an increase in the amplitude with decreased frequency of fixational saccades in children with amblyopia. These alterations in fixational eye movements correlated with the severity of their amblyopia. There was also an increase in eye position variance during drifts in amblyopes. There was no correlation between the eye position variance or the eye velocity during ocular drifts and the amplitude of subsequent fixational saccade. Our findings suggest that abnormalities in fixational saccades in amblyopia are independent of the ocular drift. Discussion This investigation of amblyopia in pediatric age group quantitatively characterizes the fixation instability. Impaired properties of fixational saccades could be the consequence of abnormal processing and reorganization of the visual system in amblyopia. Paucity in the visual feedback during amblyopic eye-viewing condition can attribute to the increased eye position variance and drift velocity. PMID:26930079

Updating visual memory across eye movements for ocular and arm motor control.

PubMed

Thompson, Aidan A; Henriques, Denise Y P

2008-11-01

Remembered object locations are stored in an eye-fixed reference frame, so that every time the eyes move, spatial representations must be updated for the arm-motor system to reflect the target's new relative position. To date, studies have not investigated how the brain updates these spatial representations during other types of eye movements, such as smooth-pursuit. Further, it is unclear what information is used in spatial updating. To address these questions we investigated whether remembered locations of pointing targets are updated following smooth-pursuit eye movements, as they are following saccades, and also investigated the role of visual information in estimating eye-movement amplitude for updating spatial memory. Misestimates of eye-movement amplitude were induced when participants visually tracked stimuli presented with a background that moved in either the same or opposite direction of the eye before pointing or looking back to the remembered target location. We found that gaze-dependent pointing errors were similar following saccades and smooth-pursuit and that incongruent background motion did result in a misestimate of eye-movement amplitude. However, the background motion had no effect on spatial updating for pointing, but did when subjects made a return saccade, suggesting that the oculomotor and arm-motor systems may rely on different sources of information for spatial updating.

Application of eye movement measuring system OBER 2 to medicine and technology

NASA Astrophysics Data System (ADS)

Ober, Jozef; Hajda, Janusz; Loska, Jacek; Jamicki, Michal

1997-08-01

The OBER 2 is an infrared light eye movement measuring system and it works with IBM PC compatible computers. As one of the safest systems for measuring of eye movement it uses a very short period of infrared light flashing time (80 microsecond for each measure point). System has an advanced analog-digital controller, which includes background suppression and prediction mechanisms guaranteeing elimination of slow changes and fluctuations of external illumination frequency up to 100 Hz, with effectiveness better than 40 dB. Setting from PC the active measure axis, sampling rate (25 - 4000 Hz) and making start and stop the measure, make it possible to control the outside environment in real-time. By proper controlling of gain it is possible to get high time and position resolution of 0.5 minute of arc even for big amplitude of eye movement (plus or minus 20 degree of visual angle). The whole communication system can also be driven directly by eye movement in real time. The possibility of automatic selection of the most essential elements of eye movement, individual for each person and those that take place for each person in determined situations of life independently from personal features, is a key to practical application. Hence one of conducted research topic is a personal identification based on personal features. Another task is a research project of falling asleep detection, which can be applied to warn the drivers before falling asleep while driving. This measuring system with a proper expert system can also be used to detect a dyslexia and other disabilities of the optic system.

Volitional and Real-Time Control Cursor Based on Eye Movement Decoding Using a Linear Decoding Model

PubMed Central

Zhang, Cheng

2016-01-01

The aim of this study is to build a linear decoding model that reveals the relationship between the movement information and the EOG (electrooculogram) data to online control a cursor continuously with blinks and eye pursuit movements. First of all, a blink detection method is proposed to reject a voluntary single eye blink or double-blink information from EOG. Then, a linear decoding model of time series is developed to predict the position of gaze, and the model parameters are calibrated by the RLS (Recursive Least Square) algorithm; besides, the assessment of decoding accuracy is assessed through cross-validation procedure. Additionally, the subsection processing, increment control, and online calibration are presented to realize the online control. Finally, the technology is applied to the volitional and online control of a cursor to hit the multiple predefined targets. Experimental results show that the blink detection algorithm performs well with the voluntary blink detection rate over 95%. Through combining the merits of blinks and smooth pursuit movements, the movement information of eyes can be decoded in good conformity with the average Pearson correlation coefficient which is up to 0.9592, and all signal-to-noise ratios are greater than 0. The novel system allows people to successfully and economically control a cursor online with a hit rate of 98%. PMID:28058044

Eye Movement Suppression Interferes with Construction of Object-Centered Spatial Reference Frames in Working Memory

ERIC Educational Resources Information Center

Wallentin, Mikkel; Kristensen, Line Burholt; Olsen, Jacob Hedeager; Nielsen, Andreas Hojlund

2011-01-01

The brain's frontal eye fields (FEF), responsible for eye movement control, are known to be involved in spatial working memory (WM). In a previous fMRI experiment (Wallentin, Roepstorff & Burgess, Neuropsychologia, 2008) it was found that FEF activation was primarily related to the formation of an object-centered, rather than egocentric, spatial…

Eye Movement Monitoring in the Study of Silent Reading.

ERIC Educational Resources Information Center

McConkie, George W.

Eye movement monitoring is useful both in the control of experiments on reading and as a source of data. Experiments using eye monitoring techniques have helped develop the following conclusions about the reading process: the region of text read during a fixation is quite small and asymmetric to the right of the center of vision, successive…

Analysis of EEG Related Saccadic Eye Movement

NASA Astrophysics Data System (ADS)

Funase, Arao; Kuno, Yoshiaki; Okuma, Shigeru; Yagi, Tohru

Our final goal is to establish the model for saccadic eye movement that connects the saccade and the electroencephalogram(EEG). As the first step toward this goal, we recorded and analyzed the saccade-related EEG. In the study recorded in this paper, we tried detecting a certain EEG that is peculiar to the eye movement. In these experiments, each subject was instructed to point their eyes toward visual targets (LEDs) or the direction of the sound sources (buzzers). In the control cases, the EEG was recorded in the case of no eye movemens. As results, in the visual experiments, we found that the potential of EEG changed sharply on the occipital lobe just before eye movement. Furthermore, in the case of the auditory experiments, similar results were observed. In the case of the visual experiments and auditory experiments without eye movement, we could not observed the EEG changed sharply. Moreover, when the subject moved his/her eyes toward a right-side target, a change in EEG potential was found on the right occipital lobe. On the contrary, when the subject moved his/her eyes toward a left-side target, a sharp change in EEG potential was found on the left occipital lobe.

Space flight and changes in spatial orientation

NASA Technical Reports Server (NTRS)

Reschke, Millard F.; Bloomberg, Jacob J.; Harm, Deborah L.; Paloski, William H.

1992-01-01

From a sensory point of view, space flight represents a form of stimulus rearrangement requiring modification of established terrestrial response patterns through central reinterpretation. Evidence of sensory reinterpretation is manifested as postflight modifications of eye/head coordination, locomotor patterns, postural control strategies, and illusory perceptions of self or surround motion in conjunction with head movements. Under normal preflight conditions, the head is stabilized during locomotion, but immediately postflight reduced head stability, coupled with inappropriate eye/head coordination, results in modifications of gait. Postflight postural control exhibits increased dependence on vision which compensates for inappropriate interpretation of otolith and proprioceptive inputs. Eye movements compensatory for perceived self motion, rather than actual head movements have been observed postflight. Overall, the in-flight adaptive modification of head stabilization strategies, changes in head/eye coordination, illusionary motion, and postural control are maladaptive for a return to the terrestrial environment. Appropriate countermeasures for long-duration flights will rely on preflight adaptation and in-flight training.

Processing Control Information in a Nominal Control Construction: An Eye-Tracking Study

ERIC Educational Resources Information Center

Kwon, Nayoung; Sturt, Patrick

2016-01-01

In an eye-tracking experiment, we examined the processing of the nominal control construction. Participants' eye-movements were monitored while they read sentences that included either giver control nominals (e.g. "promise" in "Luke's promise to Sophia to photograph himself") or recipient control nominals (e.g. "plea"…

Changes to online control and eye-hand coordination with healthy ageing.

PubMed

O'Rielly, Jessica L; Ma-Wyatt, Anna

2018-06-01

Goal directed movements are typically accompanied by a saccade to the target location. Online control plays an important part in correction of a reach, especially if the target or goal of the reach moves during the reach. While there are notable changes to visual processing and motor control with healthy ageing, there is limited evidence about how eye-hand coordination during online updating changes with healthy ageing. We sought to quantify differences between older and younger people for eye-hand coordination during online updating. Participants completed a double step reaching task implemented under time pressure. The target perturbation could occur 200, 400 and 600 ms into a reach. We measured eye position and hand position throughout the trials to investigate changes to saccade latency, movement latency, movement time, reach characteristics and eye-hand latency and accuracy. Both groups were able to update their reach in response to a target perturbation that occurred at 200 or 400 ms into the reach. All participants demonstrated incomplete online updating for the 600 ms perturbation time. Saccade latencies, measured from the first target presentation, were generally longer for older participants. Older participants had significantly increased movement times but there was no significant difference between groups for touch accuracy. We speculate that the longer movement times enable the use of new visual information about the target location for online updating towards the end of the movement. Interestingly, older participants also produced a greater proportion of secondary saccades within the target perturbation condition and had generally shorter eye-hand latencies. This is perhaps a compensatory mechanism as there was no significant group effect on final saccade accuracy. Overall, the pattern of results suggests that online control of movements may be qualitatively different in older participants. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Evaluation of the Tobii EyeX Eye tracking controller and Matlab toolkit for research.

PubMed

Gibaldi, Agostino; Vanegas, Mauricio; Bex, Peter J; Maiello, Guido

2017-06-01

The Tobii Eyex Controller is a new low-cost binocular eye tracker marketed for integration in gaming and consumer applications. The manufacturers claim that the system was conceived for natural eye gaze interaction, does not require continuous recalibration, and allows moderate head movements. The Controller is provided with a SDK to foster the development of new eye tracking applications. We review the characteristics of the device for its possible use in scientific research. We develop and evaluate an open source Matlab Toolkit that can be employed to interface with the EyeX device for gaze recording in behavioral experiments. The Toolkit provides calibration procedures tailored to both binocular and monocular experiments, as well as procedures to evaluate other eye tracking devices. The observed performance of the EyeX (i.e. accuracy < 0.6°, precision < 0.25°, latency < 50 ms and sampling frequency ≈55 Hz), is sufficient for some classes of research application. The device can be successfully employed to measure fixation parameters, saccadic, smooth pursuit and vergence eye movements. However, the relatively low sampling rate and moderate precision limit the suitability of the EyeX for monitoring micro-saccadic eye movements or for real-time gaze-contingent stimulus control. For these applications, research grade, high-cost eye tracking technology may still be necessary. Therefore, despite its limitations with respect to high-end devices, the EyeX has the potential to further the dissemination of eye tracking technology to a broad audience, and could be a valuable asset in consumer and gaming applications as well as a subset of basic and clinical research settings.

Statistical evaluation of control inputs and eye movements in the use of instruments clusters during aircraft landing

NASA Technical Reports Server (NTRS)

Dick, A. O.; Brown, J. L.; Bailey, G.

1977-01-01

Two different types of analyses were done on data from a study in which eye movements and other variables were recorded while four pilots executed landing sequences in a Boeing 737 simulation. Various conditions were manupulated, including changes in turbulence, starting position, and instrumentation. Control inputs were analyzed in the context of the various conditions and compared against ratings of workload obtained using the Cooper-Harper scale. A number of eye-scanning measures including mean dwell time and transition from one instrument to another were entered into a principal components factor analysis. The results show a differentiation between control inputs and eye-scanning behavior. This shows the need for improved definition of workload and experiments to uncover the important differences among control inputs, eye-scanning and cognitive processes of the pilot.

Investigating the causes of wrap-up effects: evidence from eye movements and E-Z Reader.

PubMed

Warren, Tessa; White, Sarah J; Reichle, Erik D

2009-04-01

Wrap-up effects in reading have traditionally been thought to reflect increased processing associated with intra- and inter-clause integration (Just, M. A. & Carpenter, P. A. (1980). A theory of reading: From eye fixations to comprehension. Psychological Review,87(4), 329-354; Rayner, K., Kambe, G., & Duffy, S. A. (2000). The effect of clause wrap-up on eye movements during reading. The Quarterly Journal of Experimental Psychology,53A(4), 1061-1080; cf. Hirotani, M., Frazier, L., & Rayner, K. (2006). Punctuation and intonation effects on clause and sentence wrap-up: Evidence from eye movements. Journal of Memory and Language,54, 425-443). We report an eye-tracking experiment with a strong manipulation of integrative complexity at a critical word that was either sentence-final, ended a comma-marked clause, or was not comma-marked. Although both complexity and punctuation had reliable effects, they did not interact in any eye-movement measure. These results as well as simulations using the E-Z Reader model of eye-movement control (Reichle, E. D., Warren, T., & McConnell, K. (2009). Using E-Z Reader to model the effects of higher-level language processing on eye movements during reading. Psychonomic Bulletin & Review,16(1), 1-20) suggest that traditional accounts of clause wrap-up are incomplete.

Smooth-pursuit eye-movement-related neuronal activity in macaque nucleus reticularis tegmenti pontis.

PubMed

Suzuki, David A; Yamada, Tetsuto; Yee, Robert D

2003-04-01

Neuronal responses that were observed during smooth-pursuit eye movements were recorded from cells in rostral portions of the nucleus reticularis tegmenti pontis (rNRTP). The responses were categorized as smooth-pursuit eye velocity (78%) or eye acceleration (22%). A separate population of rNRTP cells encoded static eye position. The sensitivity to pursuit eye velocity averaged 0.81 spikes/s per degrees /s, whereas the average sensitivity to pursuit eye acceleration was 0.20 spikes/s per degrees /s(2). Of the eye-velocity cells with horizontal preferences for pursuit responses, 56% were optimally responsive to contraversive smooth-pursuit eye movements and 44% preferred ipsiversive pursuit. For cells with vertical pursuit preferences, 61% preferred upward pursuit and 39% preferred downward pursuit. The direction selectivity was broad with 50% of the maximal response amplitude observed for directions of smooth pursuit up to +/-85 degrees away from the optimal direction. The activities of some rNRTP cells were linearly related to eye position with an average sensitivity of 2.1 spikes/s per deg. In some cells, the magnitude of the response during smooth-pursuit eye movements was affected by the position of the eyes even though these cells did not encode eye position. On average, pursuit centered to one side of screen center elicited a response that was 73% of the response amplitude obtained with tracking centered at screen center. For pursuit centered on the opposite side, the average response was 127% of the response obtained at screen center. The results provide a neuronal rationale for the slow, pursuit-like eye movements evoked with rNRTP microstimulation and for the deficits in smooth-pursuit eye movements observed with ibotenic acid injection into rNRTP. More globally, the results support the notion of a frontal and supplementary eye field-rNRTP-cerebellum pathway involved with controlling smooth-pursuit eye movements.

Caffeine increases the velocity of rapid eye movements in unfatigued humans.

PubMed

Connell, Charlotte J W; Thompson, Benjamin; Turuwhenua, Jason; Hess, Robert F; Gant, Nicholas

2017-08-01

Caffeine is a widely used dietary stimulant that can reverse the effects of fatigue on cognitive, motor and oculomotor function. However, few studies have examined the effect of caffeine on the oculomotor system when homeostasis has not been disrupted by physical fatigue. This study examined the influence of a moderate dose of caffeine on oculomotor control and visual perception in participants who were not fatigued. Within a placebo-controlled crossover design, 13 healthy adults ingested caffeine (5 mg·kg -1 body mass) and were tested over 3 h. Eye movements, including saccades, smooth pursuit and optokinetic nystagmus, were measured using infrared oculography. Caffeine was associated with higher peak saccade velocities (472 ± 60° s -1 ) compared to placebo (455 ± 62° s -1 ). Quick phases of optokinetic nystagmus were also significantly faster with caffeine, whereas pursuit eye movements were unchanged. Non-oculomotor perceptual tasks (global motion and global orientation processing) were unaffected by caffeine. These results show that oculomotor control is modulated by a moderate dose of caffeine in unfatigued humans. These effects are detectable in the kinematics of rapid eye movements, whereas pursuit eye movements and visual perception are unaffected. Oculomotor functions may be sensitive to changes in central catecholamines mediated via caffeine's action as an adenosine antagonist, even when participants are not fatigued.

Quantifying gaze and mouse interactions on spatial visual interfaces with a new movement analytics methodology

PubMed Central

2017-01-01

Eye movements provide insights into what people pay attention to, and therefore are commonly included in a variety of human-computer interaction studies. Eye movement recording devices (eye trackers) produce gaze trajectories, that is, sequences of gaze location on the screen. Despite recent technological developments that enabled more affordable hardware, gaze data are still costly and time consuming to collect, therefore some propose using mouse movements instead. These are easy to collect automatically and on a large scale. If and how these two movement types are linked, however, is less clear and highly debated. We address this problem in two ways. First, we introduce a new movement analytics methodology to quantify the level of dynamic interaction between the gaze and the mouse pointer on the screen. Our method uses volumetric representation of movement, the space-time densities, which allows us to calculate interaction levels between two physically different types of movement. We describe the method and compare the results with existing dynamic interaction methods from movement ecology. The sensitivity to method parameters is evaluated on simulated trajectories where we can control interaction levels. Second, we perform an experiment with eye and mouse tracking to generate real data with real levels of interaction, to apply and test our new methodology on a real case. Further, as our experiment tasks mimics route-tracing when using a map, it is more than a data collection exercise and it simultaneously allows us to investigate the actual connection between the eye and the mouse. We find that there seem to be natural coupling when eyes are not under conscious control, but that this coupling breaks down when instructed to move them intentionally. Based on these observations, we tentatively suggest that for natural tracing tasks, mouse tracking could potentially provide similar information as eye-tracking and therefore be used as a proxy for attention. However, more research is needed to confirm this. PMID:28777822

Quantifying gaze and mouse interactions on spatial visual interfaces with a new movement analytics methodology.

PubMed

Demšar, Urška; Çöltekin, Arzu

2017-01-01

Eye movements provide insights into what people pay attention to, and therefore are commonly included in a variety of human-computer interaction studies. Eye movement recording devices (eye trackers) produce gaze trajectories, that is, sequences of gaze location on the screen. Despite recent technological developments that enabled more affordable hardware, gaze data are still costly and time consuming to collect, therefore some propose using mouse movements instead. These are easy to collect automatically and on a large scale. If and how these two movement types are linked, however, is less clear and highly debated. We address this problem in two ways. First, we introduce a new movement analytics methodology to quantify the level of dynamic interaction between the gaze and the mouse pointer on the screen. Our method uses volumetric representation of movement, the space-time densities, which allows us to calculate interaction levels between two physically different types of movement. We describe the method and compare the results with existing dynamic interaction methods from movement ecology. The sensitivity to method parameters is evaluated on simulated trajectories where we can control interaction levels. Second, we perform an experiment with eye and mouse tracking to generate real data with real levels of interaction, to apply and test our new methodology on a real case. Further, as our experiment tasks mimics route-tracing when using a map, it is more than a data collection exercise and it simultaneously allows us to investigate the actual connection between the eye and the mouse. We find that there seem to be natural coupling when eyes are not under conscious control, but that this coupling breaks down when instructed to move them intentionally. Based on these observations, we tentatively suggest that for natural tracing tasks, mouse tracking could potentially provide similar information as eye-tracking and therefore be used as a proxy for attention. However, more research is needed to confirm this.

Controlling a human-computer interface system with a novel classification method that uses electrooculography signals.

PubMed

Wu, Shang-Lin; Liao, Lun-De; Lu, Shao-Wei; Jiang, Wei-Ling; Chen, Shi-An; Lin, Chin-Teng

2013-08-01

Electrooculography (EOG) signals can be used to control human-computer interface (HCI) systems, if properly classified. The ability to measure and process these signals may help HCI users to overcome many of the physical limitations and inconveniences in daily life. However, there are currently no effective multidirectional classification methods for monitoring eye movements. Here, we describe a classification method used in a wireless EOG-based HCI device for detecting eye movements in eight directions. This device includes wireless EOG signal acquisition components, wet electrodes and an EOG signal classification algorithm. The EOG classification algorithm is based on extracting features from the electrical signals corresponding to eight directions of eye movement (up, down, left, right, up-left, down-left, up-right, and down-right) and blinking. The recognition and processing of these eight different features were achieved in real-life conditions, demonstrating that this device can reliably measure the features of EOG signals. This system and its classification procedure provide an effective method for identifying eye movements. Additionally, it may be applied to study eye functions in real-life conditions in the near future.

Eye-Hand Coordination during Visuomotor Adaptation with Different Rotation Angles

PubMed Central

Rentsch, Sebastian; Rand, Miya K.

2014-01-01

This study examined adaptive changes of eye-hand coordination during a visuomotor rotation task. Young adults made aiming movements to targets on a horizontal plane, while looking at the rotated feedback (cursor) of hand movements on a monitor. To vary the task difficulty, three rotation angles (30°, 75°, and 150°) were tested in three groups. All groups shortened hand movement time and trajectory length with practice. However, control strategies used were different among groups. The 30° group used proportionately more implicit adjustments of hand movements than other groups. The 75° group used more on-line feedback control, whereas the 150° group used explicit strategic adjustments. Regarding eye-hand coordination, timing of gaze shift to the target was gradually changed with practice from the late to early phase of hand movements in all groups, indicating an emerging gaze-anchoring behavior. Gaze locations prior to the gaze anchoring were also modified with practice from the cursor vicinity to an area between the starting position and the target. Reflecting various task difficulties, these changes occurred fastest in the 30° group, followed by the 75° group. The 150° group persisted in gazing at the cursor vicinity. These results suggest that the function of gaze control during visuomotor adaptation changes from a reactive control for exploring the relation between cursor and hand movements to a predictive control for guiding the hand to the task goal. That gaze-anchoring behavior emerged in all groups despite various control strategies indicates a generality of this adaptive pattern for eye-hand coordination in goal-directed actions. PMID:25333942

The right look for the job: decoding cognitive processes involved in the task from spatial eye-movement patterns.

PubMed

Król, Magdalena Ewa; Król, Michał

2018-02-20

The aim of the study was not only to demonstrate whether eye-movement-based task decoding was possible but also to investigate whether eye-movement patterns can be used to identify cognitive processes behind the tasks. We compared eye-movement patterns elicited under different task conditions, with tasks differing systematically with regard to the types of cognitive processes involved in solving them. We used four tasks, differing along two dimensions: spatial (global vs. local) processing (Navon, Cognit Psychol, 9(3):353-383 1977) and semantic (deep vs. shallow) processing (Craik and Lockhart, J Verbal Learn Verbal Behav, 11(6):671-684 1972). We used eye-movement patterns obtained from two time periods: fixation cross preceding the target stimulus and the target stimulus. We found significant effects of both spatial and semantic processing, but in case of the latter, the effect might be an artefact of insufficient task control. We found above chance task classification accuracy for both time periods: 51.4% for the period of stimulus presentation and 34.8% for the period of fixation cross presentation. Therefore, we show that task can be to some extent decoded from the preparatory eye-movements before the stimulus is displayed. This suggests that anticipatory eye-movements reflect the visual scanning strategy employed for the task at hand. Finally, this study also demonstrates that decoding is possible even from very scant eye-movement data similar to Coco and Keller, J Vis 14(3):11-11 (2014). This means that task decoding is not limited to tasks that naturally take longer to perform and yield multi-second eye-movement recordings.

An eye movement pre-training fosters the comprehension of processes and functions in technical systems.

PubMed

Skuballa, Irene T; Fortunski, Caroline; Renkl, Alexander

2015-01-01

The main research goal of the present study was to investigate in how far pre-training eye movements can facilitate knowledge acquisition in multimedia (pre-training principle). We combined considerations from research on eye movement modeling and pre-training to design and test a non-verbal eye movement-based pre-training. Participants in the experimental condition watched an animated circle moving in close spatial resemblance to a static visualization of a solar plant accompanied by a narration in a subsequently presented learning environment. This training was expected to foster top-down processes as reflected in gaze behavior during the learning process and enhance knowledge acquisition. We compared two groups (N = 45): participants in the experimental condition received pre-training in a first step and processed the learning material in a second step, whereas the control group underwent the second step without any pre-training. The pre-training group outperformed the control group in their learning outcomes, particularly in knowledge about processes and functions of the solar plant. However, the superior learning outcomes in the pre-training group could not be explained by eye-movement patterns. Furthermore, the pre-training moderated the relationship between experienced stress and learning outcomes. In the control group, high stress levels hindered learning, which was not found for the pre-training group. On a delayed posttest participants were requested to draw a picture of the learning content. Despite a non-significant effect of training on the quality of drawings, the pre-training showed associations between learning outcomes at the first testing time and process-related aspects in the quality of their drawings. Overall, non-verbal pre-training is a successful instructional intervention to promote learning processes in novices although these processes did not directly reflect in learners' eye movement behavior during learning.

Davida Teller Award Lecture 2013: the importance of prediction and anticipation in the control of smooth pursuit eye movements.

PubMed

Kowler, Eileen; Aitkin, Cordelia D; Ross, Nicholas M; Santos, Elio M; Zhao, Min

2014-05-16

The ability of smooth pursuit eye movements to anticipate the future motion of targets has been known since the pioneering work of Dodge, Travis, and Fox (1930) and Westheimer (1954). This article reviews aspects of anticipatory smooth eye movements, focusing on the roles of the different internal or external cues that initiate anticipatory pursuit.We present new results showing that the anticipatory smooth eye movements evoked by different cues differ substantially, even when the cues are equivalent in the information conveyed about the direction of future target motion. Cues that convey an easily interpretable visualization of the motion path produce faster anticipatory smooth eye movements than the other cues tested, including symbols associated arbitrarily with the path, and the same target motion tested repeatedly over a block of trials. The differences among the cues may be understood within a common predictive framework in which the cues differ in the level of subjective certainty they provide about the future path. Pursuit may be driven by a combined signal in which immediate sensory motion, and the predictions about future motion generated by sets of cues, are weighted according to their respective levels of certainty. Anticipatory smooth eye movements, an overt indicator of expectations and predictions, may not be operating in isolation, but may be part of a global process in which the brain analyzes available cues, formulates predictions, and uses them to control perceptual, motor, and cognitive processes. © 2014 ARVO.

Proprioceptive role for palisade endings in extraocular muscles: evidence from the Jendrassik Maneuver.

PubMed

Niechwiej-Szwedo, E; González, E; Bega, S; Verrier, M C; Wong, A M; Steinbach, M J

2006-07-01

A proprioceptive hypothesis for the control of eye movements has been recently proposed based on neuroanatomical tracing studies. It has been suggested that the non-twitch motoneurons could be involved in modulating the gain of sensory feedback from the eye muscles analogous to the gamma (gamma) motoneurons which control the gain of proprioceptive feedback in skeletal muscles. We conducted behavioral and psychophysical experiments to test the above hypothesis using the Jendrassik Maneuver (JM) to alter the activity of gamma motoneurons. It was hypothesized that the JM would alter the proprioceptive feedback from the eye muscles which would result in misregistration of eye position and mislocalization of targets. In the first experiment, vergence eye movements and pointing responses were examined. Data showed that the JM affected the localization responses but not the actual eye position. Perceptual judgments were tested in the second experiment, and the results showed that targets were perceived as farther when the afferent feedback was altered by the JM. Overall, the results from the two experiments showed that eye position was perceived as more divergent with the JM, but the actual eye movements were not affected. We tested this further in Experiment 3 by examining the effect of JM on the amplitude and velocity of saccadic eye movements. As expected, there were no significant differences in saccadic parameters between the control and experimental conditions. Overall, the present study provides novel insight into the mechanism which may be involved in the use of sensory feedback from the eye muscles. Data from the first two experiments support the hypothesis that the JM alters the registered eye position, as evidenced by the localization errors. We propose that the altered eye position signal is due to the effect of the JM which changes the gain of the sensory feedback from the eye muscles, possibly via the activity of non-twitch motoneurons.

Distinct neural circuits for control of movement vs. holding still

PubMed Central

2017-01-01

In generating a point-to-point movement, the brain does more than produce the transient commands needed to move the body part; it also produces the sustained commands that are needed to hold the body part at its destination. In the oculomotor system, these functions are mapped onto two distinct circuits: a premotor circuit that specializes in generating the transient activity that displaces the eyes and a “neural integrator” that transforms that transient input into sustained activity that holds the eyes. Different parts of the cerebellum adaptively control the motor commands during these two phases: the oculomotor vermis participates in fine tuning the transient neural signals that move the eyes, monitoring the activity of the premotor circuit via efference copy, whereas the flocculus participates in controlling the sustained neural signals that hold the eyes, monitoring the activity of the neural integrator. Here, I review the oculomotor literature and then ask whether this separation of control between moving and holding is a design principle that may be shared with other modalities of movement. To answer this question, I consider neurophysiological and psychophysical data in various species during control of head movements, arm movements, and locomotion, focusing on the brain stem, motor cortex, and hippocampus, respectively. The review of the data raises the possibility that across modalities of motor control, circuits that are responsible for producing commands that change the sensory state of a body part are distinct from those that produce commands that maintain that sensory state. PMID:28053244

The improvement of movement and speech during rapid eye movement sleep behaviour disorder in multiple system atrophy.

PubMed

De Cock, Valérie Cochen; Debs, Rachel; Oudiette, Delphine; Leu, Smaranda; Radji, Fatai; Tiberge, Michel; Yu, Huan; Bayard, Sophie; Roze, Emmanuel; Vidailhet, Marie; Dauvilliers, Yves; Rascol, Olivier; Arnulf, Isabelle

2011-03-01

Multiple system atrophy is an atypical parkinsonism characterized by severe motor disabilities that are poorly levodopa responsive. Most patients develop rapid eye movement sleep behaviour disorder. Because parkinsonism is absent during rapid eye movement sleep behaviour disorder in patients with Parkinson's disease, we studied the movements of patients with multiple system atrophy during rapid eye movement sleep. Forty-nine non-demented patients with multiple system atrophy and 49 patients with idiopathic Parkinson's disease were interviewed along with their 98 bed partners using a structured questionnaire. They rated the quality of movements, vocal and facial expressions during rapid eye movement sleep behaviour disorder as better than, equal to or worse than the same activities in an awake state. Sleep and movements were monitored using video-polysomnography in 22/49 patients with multiple system atrophy and in 19/49 patients with Parkinson's disease. These recordings were analysed for the presence of parkinsonism and cerebellar syndrome during rapid eye movement sleep movements. Clinical rapid eye movement sleep behaviour disorder was observed in 43/49 (88%) patients with multiple system atrophy. Reports from the 31/43 bed partners who were able to evaluate movements during sleep indicate that 81% of the patients showed some form of improvement during rapid eye movement sleep behaviour disorder. These included improved movement (73% of patients: faster, 67%; stronger, 52%; and smoother, 26%), improved speech (59% of patients: louder, 55%; more intelligible, 17%; and better articulated, 36%) and normalized facial expression (50% of patients). The rate of improvement was higher in Parkinson's disease than in multiple system atrophy, but no further difference was observed between the two forms of multiple system atrophy (predominant parkinsonism versus cerebellar syndrome). Video-monitored movements during rapid eye movement sleep in patients with multiple system atrophy revealed more expressive faces, and movements that were faster and more ample in comparison with facial expression and movements during wakefulness. These movements were still somewhat jerky but lacked any visible parkinsonism. Cerebellar signs were not assessable. We conclude that parkinsonism also disappears during rapid eye movement sleep behaviour disorder in patients with multiple system atrophy, but this improvement is not due to enhanced dopamine transmission because these patients are not levodopa-sensitive. These data suggest that these movements are not influenced by extrapyramidal regions; however, the influence of abnormal cerebellar control remains unclear. The transient disappearance of parkinsonism here is all the more surprising since no treatment (even dopaminergic) provides a real benefit in this disabling disease.

Hemianopic and Quadrantanopic Field Loss, Eye and Head Movements, and Driving

PubMed Central

McGwin, Gerald; Elgin, Jennifer; Vaphiades, Michael S.; Braswell, Ronald A.; DeCarlo, Dawn K.; Kline, Lanning B.; Owsley, Cynthia

2011-01-01

Purpose. To compare eye and head movements, lane keeping, and vehicle control of drivers with hemianopic and quadrantanopic field defects with controls, and to identify differences in these parameters between hemianopic and quadrantanopic drivers rated safe to drive by a clinical driving rehabilitation specialist compared with those rated as unsafe. Methods. Eye and head movements and lane keeping were rated in 22 persons with homonymous hemianopic defects and 8 with quadrantanopic defects (mean age, 53 years) who were ≥6 months post-injury and 30 persons with normal fields (mean age, 53 years). All were licensed to drive and were current drivers or aimed to resume driving. Participants drove a 6.3-mile route along non-interstate city roads under in-traffic conditions. Vehicle control was assessed objectively by vehicle instrumentation for speed, braking, acceleration, and cornering. Results. As a group, drivers with hemianopic or quadrantanopic defects drove slower, exhibited less excessive cornering or acceleration, and executed more shoulder movements than the controls. Those drivers with hemianopic or quadrantanopic defects rated as safe also made more head movements into their blind field, received superior ratings regarding eye movement extent and lane position stability, and exhibited less sudden braking and drove faster than those rated unsafe. Conclusions. Persons with hemianopic and quadrantanopic defects rated as safe to drive compensated by making more head movements into their blind field, combined with more stable lane keeping and less sudden braking. Future research should evaluate whether these characteristics could be trained in rehabilitation programs aimed at improving driving safety in this population. PMID:21367969

Orienting movements in area 9 identified by long-train ICMS.

PubMed

Lanzilotto, M; Perciavalle, V; Lucchetti, C

2015-03-01

The effect of intracortical microstimulation has been studied in several cortical areas from motor to sensory areas. The frontal pole has received particular attention, and several microstimulation studies have been conducted in the frontal eye field, supplementary eye field, and the premotor ear-eye field, but no microstimulation studies concerning area 9 are currently available in the literature. In the present study, to fill up this gap, electrical microstimulation was applied to area 9 in two macaque monkeys using long-train pulses of 500-700-800 and 1,000 ms, during two different experimental conditions: a spontaneous condition, while the animals were not actively fixating on a visual target, and during a visual fixation task. In these experiments, we identified backward ear movements, goal-directed eye movements, and the development of head forces. Kinematic parameters for ear and eye movements overlapped in the spontaneous condition, but they were different during the visual fixation task. In this condition, ear and eye kinematics have an opposite behavior: movement amplitude, duration, and maximal and mean velocities increase during a visual fixation task for the ear, while they decrease for the eye. Therefore, a top-down visual attention engagement could modify the kinematic parameters for these two effectors. Stimulation with the longest train durations, i.e., 800/1,000 ms, evokes not only the highest eye amplitude, but also a significant development of head forces. In this research article, we propose a new vision of the frontal oculomotor fields, speculating a role for area 9 in the control of goal-directed orienting behaviors and gaze shift control.

Eye movements: The past 25 years

PubMed Central

Kowler, Eileen

2011-01-01

This article reviews the past 25 of research on eye movements (1986–2011). Emphasis is on three oculomotor behaviors: gaze control, smooth pursuit and saccades, and on their interactions with vision. Focus over the past 25 years has remained on the fundamental and classical questions: What are the mechanisms that keep gaze stable with either stationary or moving targets? How does the motion of the image on the retina affect vision? Where do we look – and why – when performing a complex task? How can the world appear clear and stable despite continual movements of the eyes? The past 25 years of investigation of these questions has seen progress and transformations at all levels due to new approaches (behavioral, neural and theoretical) aimed at studying how eye movements cope with real-world visual and cognitive demands. The work has led to a better understanding of how prediction, learning and attention work with sensory signals to contribute to the effective operation of eye movements in visually rich environments. PMID:21237189

Clinical-Radiologic Correlation of Extraocular Eye Movement Disorders: Seeing beneath the Surface.

PubMed

Thatcher, Joshua; Chang, Yu-Ming; Chapman, Margaret N; Hovis, Keegan; Fujita, Akifumi; Sobel, Rachel; Sakai, Osamu

2016-01-01

Extraocular eye movement disorders are relatively common and may be a significant source of discomfort and morbidity for patients. The presence of restricted eye movement can be detected clinically with quick, easily performed, noninvasive maneuvers that assess medial, lateral, upward, and downward gaze. However, detecting the presence of ocular dysmotility may not be sufficient to pinpoint the exact cause of eye restriction. Imaging plays an important role in excluding, in some cases, and detecting, in others, a specific cause responsible for the clinical presentation. However, the radiologist should be aware that the imaging findings in many of these conditions when taken in isolation from the clinical history and symptoms are often nonspecific. Normal eye movements are directly controlled by the ocular motor cranial nerves (CN III, IV, and VI) in coordination with indirect input or sensory stimuli derived from other cranial nerves. Specific causes of ocular dysmotility can be localized to the cranial nerve nuclei in the brainstem, the cranial nerve pathways in the peripheral nervous system, and the extraocular muscles in the orbit, with disease at any of these sites manifesting clinically as an eye movement disorder. A thorough understanding of central nervous system anatomy, cranial nerve pathways, and orbital anatomy, as well as familiarity with patterns of eye movement restriction, are necessary for accurate detection of radiologic abnormalities that support a diagnostic source of the suspected extraocular movement disorder. © RSNA, 2016.

Effect of bilateral eye movements on frontal interhemispheric gamma EEG coherence: implications for EMDR therapy.

PubMed

Propper, Ruth E; Pierce, Jenna; Geisler, Mark W; Christman, Stephen D; Bellorado, Nathan

2007-09-01

The use of bilateral eye movements (EMs) is an important component of Eye Movement Desensitization and Reprocessing (EMDR) therapy for posttraumatic stress disorder. The neural mechanisms underlying EMDR remain unclear. However, prior behavioral work looking at the effects of bilateral EMs on the retrieval of episodic memories suggests that the EMs enhance interhemispheric interaction. The present study examined the effects of the EMs used in EMDR on interhemispheric electroencephalogram coherence. Relative to noneye-movement controls, engaging in bilateral EMs led to decreased interhemispheric gamma electroencephalogram coherence. Implications for future work on EMDR and episodic memory are discussed.

Smooth pursuit eye movements and schizophrenia: literature review.

PubMed

Franco, J G; de Pablo, J; Gaviria, A M; Sepúlveda, E; Vilella, E

2014-09-01

To review the scientific literature about the relationship between impairment on smooth pursuit eye movements and schizophrenia. Narrative review that includes historical articles, reports about basic and clinical investigation, systematic reviews, and meta-analysis on the topic. Up to 80% of schizophrenic patients have impairment of smooth pursuit eye movements. Despite the diversity of test protocols, 65% of patients and controls are correctly classified by their overall performance during this pursuit. The smooth pursuit eye movements depend on the ability to anticipate the target's velocity and the visual feedback, as well as on learning and attention. The neuroanatomy implicated in smooth pursuit overlaps to some extent with certain frontal cortex zones associated with some clinical and neuropsychological characteristics of the schizophrenia, therefore some specific components of smooth pursuit anomalies could serve as biomarkers of the disease. Due to their sedative effect, antipsychotics have a deleterious effect on smooth pursuit eye movements, thus these movements cannot be used to evaluate the efficacy of the currently available treatments. Standardized evaluation of smooth pursuit eye movements on schizophrenia will allow to use specific aspects of that pursuit as biomarkers for the study of its genetics, psychopathology, or neuropsychology. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Rapid Simultaneous Enhancement of Visual Sensitivity and Perceived Contrast during Saccade Preparation

PubMed Central

Rolfs, Martin; Carrasco, Marisa

2012-01-01

Humans and other animals with foveate vision make saccadic eye movements to prioritize the visual analysis of behaviorally relevant information. Even before movement onset, visual processing is selectively enhanced at the target of a saccade, presumably gated by brain areas controlling eye movements. Here we assess concurrent changes in visual performance and perceived contrast before saccades, and show that saccade preparation enhances perception rapidly, altering early visual processing in a manner akin to increasing the physical contrast of the visual input. Observers compared orientation and contrast of a test stimulus, appearing briefly before a saccade, to a standard stimulus, presented previously during a fixation period. We found simultaneous progressive enhancement in both orientation discrimination performance and perceived contrast as time approached saccade onset. These effects were robust as early as 60 ms after the eye movement was cued, much faster than the voluntary deployment of covert attention (without eye movements), which takes ~300 ms. Our results link the dynamics of saccade preparation, visual performance, and subjective experience and show that upcoming eye movements alter visual processing by increasing the signal strength. PMID:23035086

Implicit prosody mining based on the human eye image capture technology

NASA Astrophysics Data System (ADS)

Gao, Pei-pei; Liu, Feng

2013-08-01

The technology of eye tracker has become the main methods of analyzing the recognition issues in human-computer interaction. Human eye image capture is the key problem of the eye tracking. Based on further research, a new human-computer interaction method introduced to enrich the form of speech synthetic. We propose a method of Implicit Prosody mining based on the human eye image capture technology to extract the parameters from the image of human eyes when reading, control and drive prosody generation in speech synthesis, and establish prosodic model with high simulation accuracy. Duration model is key issues for prosody generation. For the duration model, this paper put forward a new idea for obtaining gaze duration of eyes when reading based on the eye image capture technology, and synchronous controlling this duration and pronunciation duration in speech synthesis. The movement of human eyes during reading is a comprehensive multi-factor interactive process, such as gaze, twitching and backsight. Therefore, how to extract the appropriate information from the image of human eyes need to be considered and the gaze regularity of eyes need to be obtained as references of modeling. Based on the analysis of current three kinds of eye movement control model and the characteristics of the Implicit Prosody reading, relative independence between speech processing system of text and eye movement control system was discussed. It was proved that under the same text familiarity condition, gaze duration of eyes when reading and internal voice pronunciation duration are synchronous. The eye gaze duration model based on the Chinese language level prosodic structure was presented to change previous methods of machine learning and probability forecasting, obtain readers' real internal reading rhythm and to synthesize voice with personalized rhythm. This research will enrich human-computer interactive form, and will be practical significance and application prospect in terms of disabled assisted speech interaction. Experiments show that Implicit Prosody mining based on the human eye image capture technology makes the synthesized speech has more flexible expressions.

Expansion of visual space during optokinetic afternystagmus (OKAN).

PubMed

Kaminiarz, André; Krekelberg, Bart; Bremmer, Frank

2008-05-01

The mechanisms underlying visual perceptual stability are usually investigated using voluntary eye movements. In such studies, errors in perceptual stability during saccades and pursuit are commonly interpreted as mismatches between actual eye position and eye-position signals in the brain. The generality of this interpretation could in principle be tested by investigating spatial localization during reflexive eye movements whose kinematics are very similar to those of voluntary eye movements. Accordingly, in this study, we determined mislocalization of flashed visual targets during optokinetic afternystagmus (OKAN). These eye movements are quite unique in that they occur in complete darkness and are generated by subcortical control mechanisms. We found that during horizontal OKAN slow phases, subjects mislocalize targets away from the fovea in the horizontal direction. This corresponds to a perceived expansion of visual space and is unlike mislocalization found for any other voluntary or reflexive eye movement. Around the OKAN fast phases, we found a bias in the direction of the fast phase prior to its onset and opposite to the fast-phase direction thereafter. Such a biphasic modulation has also been reported in the temporal vicinity of saccades and during optokinetic nystagmus (OKN). A direct comparison, however, showed that the modulation during OKAN was much larger and occurred earlier relative to fast-phase onset than during OKN. A simple mismatch between the current eye position and the eye-position signal in the brain is unlikely to explain such disparate results across similar eye movements. Instead, these data support the view that mislocalization arises from errors in eye-centered position information.

Eye Movements Affect Postural Control in Young and Older Females

PubMed Central

Thomas, Neil M.; Bampouras, Theodoros M.; Donovan, Tim; Dewhurst, Susan

2016-01-01

Visual information is used for postural stabilization in humans. However, little is known about how eye movements prevalent in everyday life interact with the postural control system in older individuals. Therefore, the present study assessed the effects of stationary gaze fixations, smooth pursuits, and saccadic eye movements, with combinations of absent, fixed and oscillating large-field visual backgrounds to generate different forms of retinal flow, on postural control in healthy young and older females. Participants were presented with computer generated visual stimuli, whilst postural sway and gaze fixations were simultaneously assessed with a force platform and eye tracking equipment, respectively. The results showed that fixed backgrounds and stationary gaze fixations attenuated postural sway. In contrast, oscillating backgrounds and smooth pursuits increased postural sway. There were no differences regarding saccades. There were also no differences in postural sway or gaze errors between age groups in any visual condition. The stabilizing effect of the fixed visual stimuli show how retinal flow and extraocular factors guide postural adjustments. The destabilizing effect of oscillating visual backgrounds and smooth pursuits may be related to more challenging conditions for determining body shifts from retinal flow, and more complex extraocular signals, respectively. Because the older participants matched the young group's performance in all conditions, decreases of posture and gaze control during stance may not be a direct consequence of healthy aging. Further research examining extraocular and retinal mechanisms of balance control and the effects of eye movements, during locomotion, is needed to better inform fall prevention interventions. PMID:27695412

Eye Movements Affect Postural Control in Young and Older Females.

PubMed

Thomas, Neil M; Bampouras, Theodoros M; Donovan, Tim; Dewhurst, Susan

2016-01-01

Visual information is used for postural stabilization in humans. However, little is known about how eye movements prevalent in everyday life interact with the postural control system in older individuals. Therefore, the present study assessed the effects of stationary gaze fixations, smooth pursuits, and saccadic eye movements, with combinations of absent, fixed and oscillating large-field visual backgrounds to generate different forms of retinal flow, on postural control in healthy young and older females. Participants were presented with computer generated visual stimuli, whilst postural sway and gaze fixations were simultaneously assessed with a force platform and eye tracking equipment, respectively. The results showed that fixed backgrounds and stationary gaze fixations attenuated postural sway. In contrast, oscillating backgrounds and smooth pursuits increased postural sway. There were no differences regarding saccades. There were also no differences in postural sway or gaze errors between age groups in any visual condition. The stabilizing effect of the fixed visual stimuli show how retinal flow and extraocular factors guide postural adjustments. The destabilizing effect of oscillating visual backgrounds and smooth pursuits may be related to more challenging conditions for determining body shifts from retinal flow, and more complex extraocular signals, respectively. Because the older participants matched the young group's performance in all conditions, decreases of posture and gaze control during stance may not be a direct consequence of healthy aging. Further research examining extraocular and retinal mechanisms of balance control and the effects of eye movements, during locomotion, is needed to better inform fall prevention interventions.

Fluid Mixing in the Eye Under Rapid Eye Movement

NASA Astrophysics Data System (ADS)

Huang, Jinglin; Gharib, Morteza

2017-11-01

Drug injection is an important technique in certain treatments of eye diseases. The efficacy of chemical mixing plays an important role in determining pharmacokinetics of injected drugs. In this study, we build a device to study the chemical mixing behavior in a spherical structure. The mixing process is visualized and analyzed qualitatively. We hope to understand the chemical convection and diffusion behaviors in correlation with controlled rapid mechanical movements. The results will have potential applications in treatment of eye diseases. Resnick Institute at Caltech.

Eye movements evoked by electrical microstimulation of the mesencephalic reticular formation in goldfish.

PubMed

Luque, M A; Pérez-Pérez, M P; Herrero, L; Waitzman, D M; Torres, B

2006-02-01

Anatomical studies in goldfish show that the tectofugal axons provide a large number of boutons within the mesencephalic reticular formation. Electrical stimulation, reversible inactivation and cell recording in the primate central mesencephalic reticular formation have suggested that it participates in the control of rapid eye movements (saccades). Moreover, the role of this tecto-recipient area in the generation of saccadic eye movements in fish is unknown. In this study we show that the electrical microstimulation of the mesencephalic reticular formation of goldfish evoked short latency saccadic eye movements in any direction (contraversive or ipsiversive, upward or downward). Movements of the eyes were usually disjunctive. Based on the location of the sites from which eye movements were evoked and the preferred saccade direction, eye movements were divided into different groups: pure vertical saccades were mainly elicited from the rostral mesencephalic reticular formation, while oblique and pure horizontal were largely evoked from middle and caudal mesencephalic reticular formation zones. The direction and amplitude of pure vertical and horizontal saccades were unaffected by initial eye position. However the amplitude, but not the direction of most oblique saccades was systematically modified by initial eye position. At the same time, the amplitude of elicited saccades did not vary in any consistent manner along either the anteroposterior, dorsoventral or mediolateral axes (i.e. there was no topographic organization of the mesencephalic reticular formation with respect to amplitude). In addition to these groups of movements, we found convergent and goal-directed saccades evoked primarily from the anterior and posterior mesencephalic reticular formation, respectively. Finally, the metric and kinetic characteristics of saccades could be manipulated by changes in the stimulation parameters. We conclude that the mesencephalic reticular formation in goldfish shares physiological functions that correspond closely with those found in mammals.

Consequences of Traumatic Brain Injury for Human Vergence Dynamics

PubMed Central

Tyler, Christopher W.; Likova, Lora T.; Mineff, Kristyo N.; Elsaid, Anas M.; Nicholas, Spero C.

2015-01-01

Purpose: Traumatic brain injury involving loss of consciousness has focal effects in the human brainstem, suggesting that it may have particular consequences for eye movement control. This hypothesis was investigated by measurements of vergence eye movement parameters. Methods: Disparity vergence eye movements were measured for a population of 123 normally sighted individuals, 26 of whom had suffered diffuse traumatic brain injury (dTBI) in the past, while the remainder served as controls. Vergence tracking responses were measured to sinusoidal disparity modulation of a random-dot field. Disparity vergence step responses were characterized in terms of their dynamic parameters separately for the convergence and divergence directions. Results: The control group showed notable differences between convergence and divergence dynamics. The dTBI group showed significantly abnormal vergence behavior on many of the dynamic parameters. Conclusion: The results support the hypothesis that occult injury to the oculomotor control system is a common residual outcome of dTBI. PMID:25691880

Motion sickness elicited by passive rotation in squirrel monkeys

NASA Technical Reports Server (NTRS)

Daunton, Nancy G.; Fox, Robert A.

1991-01-01

Current theory and recent evidence suggest that motion sickness occurs under conditions of sensory input in which the normal motor programs for producing eye, head, and body movements are not functionally effective, i.e. under conditions in which there are difficulties in maintaining posture and controlling eye movements. Conditions involving conflicting or inconsistent visual-vestibular (VV) stimulation should thus result in greater sickness rates since the existing motor programs do not produce effective control of eye-head-body movements under such conditions. It is felt that the relationship of postural control to motion sickness is an important one and one often overlooked. The results are reported which showed that when postural requirements were minimized by fully restraining squirrel monkeys during hypogravity parabolic flight, no animals became motion sick, but over 80 percent of the same 11 animals became sick if they were unrestrained and maintained control of their posture.

Interactions of cervico-ocular and vestibulo-ocular fast-phase signals in the control of eye position in rabbits.

PubMed Central

Barmack, N H; Errico, P; Ferraresi, A; Pettorossi, V E

1989-01-01

1. Eye movements in unanaesthetized rabbits were studied during horizontal neck-proprioceptive stimulation (movement of the body with respect to the fixed head), when this stimulation was given alone and when it was given simultaneously with vestibular stimulation (rotation of the head-body). The effect of neck-proprioceptive stimulation on modifying the anticompensatory fast-phase eye movements (AFPs) evoked by vestibular stimulation was studied with a 'conditioning-test' protocol; the 'conditioning' stimulus was a neck-proprioceptive signal evoked by a step-like change in body position with respect to the head and the 'test' stimulus was a vestibular signal evoked by a step rotation of the head-body. 2. The influence of eye position and direction of slow eye movements on the occurrence of compensatory fast-phase eye movements (CFPs) evoked by neck-proprioceptive stimulation was also examined. 3. The anticompensatory fast phase (AFP) evoked by vestibular stimulation was attenuated by a preceding neck-proprioceptive stimulus which when delivered alone evoked compensatory slow-phase eye movements (CSP) in the same direction as the CSP evoked by vestibular stimulation. Conversely, the vestibularly evoked AFP was potentiated by a neck-proprioceptive stimulus which evoked CSPs opposite to that of vestibularly evoked CSPs. 4. Eccentric initial eye positions increased the probability of occurrence of midline-directed compensatory fast-phase eye movements (CFPs) evoked by appropriate neck-proprioceptive stimulation. 5. The gain of the horizontal cervico-ocular reflex (GHCOR) was measured from the combined changes in eye position resulting from AFPs and CSPs. GHCOR was potentiated during simultaneous vestibular stimulation. This enhancement of GHCOR occurred at neck-proprioceptive stimulus frequencies which, in the absence of conjoint vestibular stimulation, do not evoke CSPs. PMID:2795479

Alcohol and disorientation-responses. VI, Effects of alcohol on eye movements and tracking performance during laboratory angular accelerations about the yaw and pitch axes.

DOT National Transportation Integrated Search

1972-12-01

Alcohol ingestion interferes with visual control of vestibular eye movements and thereby produces significant decrements in performance at a compensatory tracking task during oscillation about the yaw axis; significant or consistent decrements in per...

Pharmacological Treatment Effects on Eye Movement Control

ERIC Educational Resources Information Center

Reilly, James L.; Lencer, Rebekka; Bishop, Jeffrey R.; Keedy, Sarah; Sweeney, John A.

2008-01-01

The increasing use of eye movement paradigms to assess the functional integrity of brain systems involved in sensorimotor and cognitive processing in clinical disorders requires greater attention to effects of pharmacological treatments on these systems. This is needed to better differentiate disease and medication effects in clinical samples, to…

Contextual effects on smooth-pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R

2007-02-01

Segregating a moving object from its visual context is particularly relevant for the control of smooth-pursuit eye movements. We examined the interaction between a moving object and a stationary or moving visual context to determine the role of the context motion signal in driving pursuit. Eye movements were recorded from human observers to a medium-contrast Gaussian dot that moved horizontally at constant velocity. A peripheral context consisted of two vertically oriented sinusoidal gratings, one above and one below the stimulus trajectory, that were either stationary or drifted into the same or opposite direction as that of the target at different velocities. We found that a stationary context impaired pursuit acceleration and velocity and prolonged pursuit latency. A drifting context enhanced pursuit performance, irrespective of its motion direction. This effect was modulated by context contrast and orientation. When a context was briefly perturbed to move faster or slower eye velocity changed accordingly, but only when the context was drifting along with the target. Perturbing a context into the direction orthogonal to target motion evoked a deviation of the eye opposite to the perturbation direction. We therefore provide evidence for the use of absolute and relative motion cues, or motion assimilation and motion contrast, for the control of smooth-pursuit eye movements.

Consistent abnormalities in metabolic network activity in idiopathic rapid eye movement sleep behaviour disorder.

PubMed

Wu, Ping; Yu, Huan; Peng, Shichun; Dauvilliers, Yves; Wang, Jian; Ge, Jingjie; Zhang, Huiwei; Eidelberg, David; Ma, Yilong; Zuo, Chuantao

2014-12-01

Rapid eye movement sleep behaviour disorder has been evaluated using Parkinson's disease-related metabolic network. It is unknown whether this disorder is itself associated with a unique metabolic network. 18F-fluorodeoxyglucose positron emission tomography was performed in 21 patients (age 65.0±5.6 years) with idiopathic rapid eye movement sleep behaviour disorder and 21 age/gender-matched healthy control subjects (age 62.5±7.5 years) to identify a disease-related pattern and examine its evolution in 21 hemi-parkinsonian patients (age 62.6±5.0 years) and 16 moderate parkinsonian patients (age 56.9±12.2 years). We identified a rapid eye movement sleep behaviour disorder-related metabolic network characterized by increased activity in pons, thalamus, medial frontal and sensorimotor areas, hippocampus, supramarginal and inferior temporal gyri, and posterior cerebellum, with decreased activity in occipital and superior temporal regions. Compared to the healthy control subjects, network expressions were elevated (P<0.0001) in the patients with this disorder and in the parkinsonian cohorts but decreased with disease progression. Parkinson's disease-related network activity was also elevated (P<0.0001) in the patients with rapid eye movement sleep behaviour disorder but lower than in the hemi-parkinsonian cohort. Abnormal metabolic networks may provide markers of idiopathic rapid eye movement sleep behaviour disorder to identify those at higher risk to develop neurodegenerative parkinsonism. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Disturbance of Gaze in Progressive Supranuclear Palsy: Implications for Pathogenesis

PubMed Central

Chen, Athena L.; Riley, David E.; King, Susan A.; Joshi, Anand C.; Serra, Alessandro; Liao, Ke; Cohen, Mark L.; Otero-Millan, Jorge; Martinez-Conde, Susana; Strupp, Michael; Leigh, R. John

2010-01-01

Progressive supranuclear palsy (PSP) is a disease of later life that is currently regarded as a form of neurodegenerative tauopathy. Disturbance of gaze is a cardinal clinical feature of PSP that often helps clinicians to establish the diagnosis. Since the neurobiology of gaze control is now well understood, it is possible to use eye movements as investigational tools to understand aspects of the pathogenesis of PSP. In this review, we summarize each disorder of gaze control that occurs in PSP, drawing on our studies of 50 patients, and on reports from other laboratories that have measured the disturbances of eye movements. When these gaze disorders are approached by considering each functional class of eye movements and its neurobiological basis, a distinct pattern of eye movement deficits emerges that provides insight into the pathogenesis of PSP. Although some aspects of all forms of eye movements are affected in PSP, the predominant defects concern vertical saccades (slow and hypometric, both up and down), impaired vergence, and inability to modulate the linear vestibulo-ocular reflex appropriately for viewing distance. These vertical and vergence eye movements habitually work in concert to enable visuomotor skills that are important during locomotion with the hands free. Taken with the prominent early feature of falls, these findings suggest that PSP tauopathy impairs a recently evolved neural system concerned with bipedal locomotion in an erect posture and frequent gaze shifts between the distant environment and proximate hands. This approach provides a conceptual framework that can be used to address the nosological challenge posed by overlapping clinical and neuropathological features of neurodegenerative tauopathies. PMID:21188269

Contrast and assimilation in motion perception and smooth pursuit eye movements.

PubMed

Spering, Miriam; Gegenfurtner, Karl R

2007-09-01

The analysis of visual motion serves many different functions ranging from object motion perception to the control of self-motion. The perception of visual motion and the oculomotor tracking of a moving object are known to be closely related and are assumed to be controlled by shared brain areas. We compared perceived velocity and the velocity of smooth pursuit eye movements in human observers in a paradigm that required the segmentation of target object motion from context motion. In each trial, a pursuit target and a visual context were independently perturbed simultaneously to briefly increase or decrease in speed. Observers had to accurately track the target and estimate target speed during the perturbation interval. Here we show that the same motion signals are processed in fundamentally different ways for perception and steady-state smooth pursuit eye movements. For the computation of perceived velocity, motion of the context was subtracted from target motion (motion contrast), whereas pursuit velocity was determined by the motion average (motion assimilation). We conclude that the human motion system uses these computations to optimally accomplish different functions: image segmentation for object motion perception and velocity estimation for the control of smooth pursuit eye movements.

System for assisted mobility using eye movements based on electrooculography.

PubMed

Barea, Rafael; Boquete, Luciano; Mazo, Manuel; López, Elena

2002-12-01

This paper describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electroculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

Quality of life in patients with an idiopathic rapid eye movement sleep behaviour disorder in Korea.

PubMed

Kim, Keun Tae; Motamedi, Gholam K; Cho, Yong Won

2017-08-01

There have been few quality of life studies in patients with idiopathic rapid eye movement sleep behaviour disorder. We compared the quality of life in idiopathic rapid eye movement sleep behaviour disorder patients to healthy controls, patients with hypertension, type 2 diabetes mellitus without complication and idiopathic restless legs syndrome. Sixty patients with idiopathic rapid eye movement sleep behaviour disorder (24 female; mean age: 61.43 ± 8.99) were enrolled retrospectively. The diagnosis was established based on sleep history, overnight polysomnography, neurological examination and Mini-Mental State Examination to exclude secondary rapid eye movement sleep behavior disorder. All subjects completed questionnaires, including the Short Form 36-item Health Survey for quality of life. The total quality of life score in idiopathic rapid eye movement sleep behaviour disorder (70.63 ± 20.83) was lower than in the healthy control group (83.38 ± 7.96) but higher than in the hypertension (60.55 ± 24.82), diabetes mellitus (62.42 ± 19.37) and restless legs syndrome (61.77 ± 19.25) groups. The total score of idiopathic rapid eye movement sleep behaviour disorder patients had a negative correlation with the Pittsburg Sleep Quality Index (r = -0.498, P < 0.001), Insomnia Severity Index (r = -0.645, P < 0.001) and the Beck Depression Inventory-2 (r = -0.694, P < 0.001). Multiple regression showed a negative correlation between the Short Form 36-item Health Survey score and the Insomnia Severity Index (β = -1.100, P = 0.001) and Beck Depression Inventory-2 (β = -1.038, P < 0.001). idiopathic rapid eye movement sleep behaviour disorder had a significant negative impact on quality of life, although this effect was less than that of other chronic disorders. This negative effect might be related to a depressive mood associated with the disease. © 2016 European Sleep Research Society.

Eye movements during visual search in patients with glaucoma

PubMed Central

2012-01-01

Background Glaucoma has been shown to lead to disability in many daily tasks including visual search. This study aims to determine whether the saccadic eye movements of people with glaucoma differ from those of people with normal vision, and to investigate the association between eye movements and impaired visual search. Methods Forty patients (mean age: 67 [SD: 9] years) with a range of glaucomatous visual field (VF) defects in both eyes (mean best eye mean deviation [MD]: –5.9 (SD: 5.4) dB) and 40 age-related people with normal vision (mean age: 66 [SD: 10] years) were timed as they searched for a series of target objects in computer displayed photographs of real world scenes. Eye movements were simultaneously recorded using an eye tracker. Average number of saccades per second, average saccade amplitude and average search duration across trials were recorded. These response variables were compared with measurements of VF and contrast sensitivity. Results The average rate of saccades made by the patient group was significantly smaller than the number made by controls during the visual search task (P = 0.02; mean reduction of 5.6% (95% CI: 0.1 to 10.4%). There was no difference in average saccade amplitude between the patients and the controls (P = 0.09). Average number of saccades was weakly correlated with aspects of visual function, with patients with worse contrast sensitivity (PR logCS; Spearman’s rho: 0.42; P = 0.006) and more severe VF defects (best eye MD; Spearman’s rho: 0.34; P = 0.037) tending to make less eye movements during the task. Average detection time in the search task was associated with the average rate of saccades in the patient group (Spearman’s rho = −0.65; P < 0.001) but this was not apparent in the controls. Conclusions The average rate of saccades made during visual search by this group of patients was fewer than those made by people with normal vision of a similar average age. There was wide variability in saccade rate in the patients but there was an association between an increase in this measure and better performance in the search task. Assessment of eye movements in individuals with glaucoma might provide insight into the functional deficits of the disease. PMID:22937814

Sex differences in objective measures of sleep in post-traumatic stress disorder and healthy control subjects.

PubMed

Richards, Anne; Metzler, Thomas J; Ruoff, Leslie M; Inslicht, Sabra S; Rao, Madhu; Talbot, Lisa S; Neylan, Thomas C

2013-12-01

A growing literature shows prominent sex effects for risk for post-traumatic stress disorder and associated medical comorbid burden. Previous research indicates that post-traumatic stress disorder is associated with reduced slow wave sleep, which may have implications for overall health, and abnormalities in rapid eye movement sleep, which have been implicated in specific post-traumatic stress disorder symptoms, but most research has been conducted in male subjects. We therefore sought to compare objective measures of sleep in male and female post-traumatic stress disorder subjects with age- and sex-matched control subjects. We used a cross-sectional, 2 × 2 design (post-traumatic stress disorder/control × female/male) involving83 medically healthy, non-medicated adults aged 19-39 years in the inpatient sleep laboratory. Visual electroencephalographic analysis demonstrated that post-traumatic stress disorder was associated with lower slow wave sleep duration (F(3,82)  = 7.63, P = 0.007) and slow wave sleep percentage (F(3,82)  = 6.11, P = 0.016). There was also a group × sex interaction effect for rapid eye movement sleep duration (F(3,82)  = 4.08, P = 0.047) and rapid eye movement sleep percentage (F(3,82)  = 4.30, P = 0.041), explained by greater rapid eye movement sleep in post-traumatic stress disorder females compared to control females, a difference not seen in male subjects. Quantitative electroencephalography analysis demonstrated that post-traumatic stress disorder was associated with lower energy in the delta spectrum (F(3,82)  = 6.79, P = 0.011) in non-rapid eye movement sleep. Slow wave sleep and delta findings were more pronounced in males. Removal of post-traumatic stress disorder subjects with comorbid major depressive disorder, who had greater post-traumatic stress disorder severity, strengthened delta effects but reduced rapid eye movement effects to non-significance. These findings support previous evidence that post-traumatic stress disorder is associated with impairment in the homeostatic function of sleep, especially in men with the disorder. These findings suggest that group × sex interaction effects on rapid eye movement may occur with more severe post-traumatic stress disorder or with post-traumatic stress disorder comorbid with major depressive disorder. © 2013 European Sleep Research Society.

Fixational Eye Movements in the Earliest Stage of Metazoan Evolution

PubMed Central

Bielecki, Jan; Høeg, Jens T.; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur. PMID:23776673

Fixational eye movements in the earliest stage of metazoan evolution.

PubMed

Bielecki, Jan; Høeg, Jens T; Garm, Anders

2013-01-01

All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

Standing balance tests for screening people with vestibular impairments.

PubMed

Cohen, Helen S; Mulavara, Ajitkumar P; Peters, Brian T; Sangi-Haghpeykar, Haleh; Bloomberg, Jacob J

2014-02-01

To improve the test standards for a version of the Romberg test and to determine whether measuring kinematic variables improved its utility for screening. Healthy controls and patients with benign paroxysmal positional vertigo, postoperative acoustic neuroma resection, and chronic peripheral unilateral weakness were compared. Subjects wore Bluetooth-enabled inertial motion units while standing on the floor or medium-density, compliant foam, with eyes open or closed, with head still or moving in pitch or yaw. Dependent measures were time to perform each test condition, number of head movements made, and kinematic variables. Patients and controls did not differ significantly with eyes open or with eyes closed while on the floor. With eyes closed, on foam, some significant differences were found between patients and controls, especially for subjects older than 59 years. Head movement conditions were more challenging than with the head still. Significantly fewer patients than controls could make enough head movements to obtain kinematic measures. Kinematics indicated that lateral balance control is significantly reduced in these patients compared to controls. Receiver operator characteristics and sensitivity/specificity analyses showed moderately good differences with older subjects. Tests on foam with eyes closed, with head still or moving, may be useful as part of a screening battery for vestibular impairments, especially for older people. 3b. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

A Biologically Realistic Cortical Model of Eye Movement Control in Reading

ERIC Educational Resources Information Center

Heinzle, Jakob; Hepp, Klaus; Martin, Kevan A. C.

2010-01-01

Reading is a highly complex task involving a precise integration of vision, attention, saccadic eye movements, and high-level language processing. Although there is a long history of psychological research in reading, it is only recently that imaging studies have identified some neural correlates of reading. Thus, the underlying neural mechanisms…

Vergence Deficits in Patients with Cerebellar Lesions

ERIC Educational Resources Information Center

Sander, T.; Sprenger, A.; Neumann, G.; Machner, B.; Gottschalk, S.; Rambold, H.; Helmchen, C.

2009-01-01

The cerebellum is part of the cortico-ponto-cerebellar circuit for conjugate eye movements. Recent animal data suggest an additional role of the cerebellum for the control of binocular alignment and disconjugate, i.e. vergence eye movements. The latter is separated into two different components: fast vergence (to step targets) and slow vergence…

Reduced Misinformation Effects Following Saccadic Bilateral Eye Movements

ERIC Educational Resources Information Center

Parker, Andrew; Buckley, Sharon; Dagnall, Neil

2009-01-01

The effects of saccadic bilateral (horizontal) eye movements on memory for a visual event narrative were investigated. In the study phase, participants were exposed to a set of pictures accompanied by a verbal commentary describing the events depicted in the pictures. Next, the participants were asked either misleading or control questions about…

Semantic Preview Benefit in Eye Movements during Reading: A Parafoveal Fast-Priming Study

ERIC Educational Resources Information Center

Hohenstein, Sven; Laubrock, Jochen; Kliegl, Reinhold

2010-01-01

Eye movements in reading are sensitive to foveal and parafoveal word features. Whereas the influence of orthographic or phonological parafoveal information on gaze control is undisputed, there has been no reliable evidence for early parafoveal extraction of semantic information in alphabetic script. Using a novel combination of the gaze-contingent…

A Statistical Physics Perspective to Understand Social Visual Attention in Autism Spectrum Disorder.

PubMed

Liberati, Alessio; Fadda, Roberta; Doneddu, Giuseppe; Congiu, Sara; Javarone, Marco A; Striano, Tricia; Chessa, Alessandro

2017-08-01

This study investigated social visual attention in children with Autism Spectrum Disorder (ASD) and with typical development (TD) in the light of Brockmann and Geisel's model of visual attention. The probability distribution of gaze movements and clustering of gaze points, registered with eye-tracking technology, was studied during a free visual exploration of a gaze stimulus. A data-driven analysis of the distribution of eye movements was chosen to overcome any possible methodological problems related to the subjective expectations of the experimenters about the informative contents of the image in addition to a computational model to simulate group differences. Analysis of the eye-tracking data indicated that the scanpaths of children with TD and ASD were characterized by eye movements geometrically equivalent to Lévy flights. Children with ASD showed a higher frequency of long saccadic amplitudes compared with controls. A clustering analysis revealed a greater dispersion of eye movements for these children. Modeling of the results indicated higher values of the model parameter modulating the dispersion of eye movements for children with ASD. Together, the experimental results and the model point to a greater dispersion of gaze points in ASD.

Smooth-pursuit eye-movement deficits with chemical lesions in macaque nucleus reticularis tegmenti pontis.

PubMed

Suzuki, D A; Yamada, T; Hoedema, R; Yee, R D

1999-09-01

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over approximately 3 days when maintained pursuit gains attained normal values. The step-ramp, "Rashbass" task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

Eye, head, and body coordination during large gaze shifts in rhesus monkeys: movement kinematics and the influence of posture.

PubMed

McCluskey, Meaghan K; Cullen, Kathleen E

2007-04-01

Coordinated movements of the eye, head, and body are used to redirect the axis of gaze between objects of interest. However, previous studies of eye-head gaze shifts in head-unrestrained primates generally assumed the contribution of body movement to be negligible. Here we characterized eye-head-body coordination during horizontal gaze shifts made by trained rhesus monkeys to visual targets while they sat upright in a standard primate chair and assumed a more natural sitting posture in a custom-designed chair. In both postures, gaze shifts were characterized by the sequential onset of eye, head, and body movements, which could be described by predictable relationships. Body motion made a small but significant contribution to gaze shifts that were > or =40 degrees in amplitude. Furthermore, as gaze shift amplitude increased (40-120 degrees ), body contribution and velocity increased systematically. In contrast, peak eye and head velocities plateaued at velocities of approximately 250-300 degrees /s, and the rotation of the eye-in-orbit and head-on-body remained well within the physical limits of ocular and neck motility during large gaze shifts, saturating at approximately 35 and 60 degrees , respectively. Gaze shifts initiated with the eye more contralateral in the orbit were accompanied by smaller body as well as head movement amplitudes and velocities were greater when monkeys were seated in the more natural body posture. Taken together, our findings show that body movement makes a predictable contribution to gaze shifts that is systematically influenced by factors such as orbital position and posture. We conclude that body movements are part of a coordinated series of motor events that are used to voluntarily reorient gaze and that these movements can be significant even in a typical laboratory setting. Our results emphasize the need for caution in the interpretation of data from neurophysiological studies of the control of saccadic eye movements and/or eye-head gaze shifts because single neurons can code motor commands to move the body as well as the head and eyes.

Parkinson’s disease patients show impaired corrective grasp control and eye-hand coupling when reaching to grasp virtual objects

PubMed Central

Lukos, Jamie R.; Snider, Joseph; Hernandez, Manuel E.; Tunik, Eugene; Hillyard, Steven; Poizner, Howard

2013-01-01

The effect of Parkinson’s disease on hand-eye coordination and corrective response control during reach-to-grasp tasks remains unclear. Moderately impaired Parkinson’s disease patients (PD, n=9) and age-matched controls (n=12) reached to and grasped a virtual rectangular object, with haptic feedback provided to the thumb and index fingertip by two 3-degree of freedom manipulanda. The object rotated unexpectedly on a minority of trials, requiring subjects to adjust their grasp aperture. On half the trials, visual feedback of finger positions disappeared during the initial phase of the reach, when feedforward mechanisms are known to guide movement. PD patients were tested without (OFF) and with (ON) medication to investigate the effects of dopamine depletion and repletion on eye-hand coordination online corrective response control. We quantified eye-hand coordination by monitoring hand kinematics and eye position during the reach. We hypothesized that if the basal ganglia are important for eye-hand coordination and online corrections to object perturbations, then PD patients tested OFF medication would show reduced eye-hand spans and impoverished arm-hand coordination responses to the perturbation, which would be further exasperated when visual feedback of the hand was removed. Strikingly, PD patients tracked their hands with their gaze, and their movements became destabilized when having to make online corrective responses to object perturbations exhibiting pauses and changes in movement direction. These impairments largely remained even when tested in the ON state, despite significant improvement on the Unified Parkinson’s Disease Rating Scale. Our findings suggest that basal ganglia-cortical loops are essential for mediating eye-hand coordination and adaptive online responses for reach-to-grasp movements, and that restoration of tonic levels of dopamine may not be adequate to remediate this coordinative nature of basal ganglia modulated function. PMID:24056196

Effect of glaucoma on eye movement patterns and laboratory-based hazard detection ability

PubMed Central

Black, Alex A.; Wood, Joanne M.

2017-01-01

Purpose The mechanisms underlying the elevated crash rates of older drivers with glaucoma are poorly understood. A key driving skill is timely detection of hazards; however, the hazard detection ability of drivers with glaucoma has been largely unexplored. This study assessed the eye movement patterns and visual predictors of performance on a laboratory-based hazard detection task in older drivers with glaucoma. Methods Participants included 30 older drivers with glaucoma (71±7 years; average better-eye mean deviation (MD) = −3.1±3.2 dB; average worse-eye MD = −11.9±6.2 dB) and 25 age-matched controls (72±7 years). Visual acuity, contrast sensitivity, visual fields, useful field of view (UFoV; processing speeds), and motion sensitivity were assessed. Participants completed a computerised Hazard Perception Test (HPT) while their eye movements were recorded using a desk-mounted Tobii TX300 eye-tracking system. The HPT comprises a series of real-world traffic videos recorded from the driver’s perspective; participants responded to road hazards appearing in the videos, and hazard response times were determined. Results Participants with glaucoma exhibited an average of 0.42 seconds delay in hazard response time (p = 0.001), smaller saccades (p = 0.010), and delayed first fixation on hazards (p<0.001) compared to controls. Importantly, larger saccades were associated with faster hazard responses in the glaucoma group (p = 0.004), but not in the control group (p = 0.19). Across both groups, significant visual predictors of hazard response times included motion sensitivity, UFoV, and worse-eye MD (p<0.05). Conclusions Older drivers with glaucoma had delayed hazard response times compared to controls, with associated changes in eye movement patterns. The association between larger saccades and faster hazard response time in the glaucoma group may represent a compensatory behaviour to facilitate improved performance. PMID:28570621

Diurnal changes in the power spectral characteristics of eye movements and heart rate variability in the human fetus at term.

PubMed

Morokuma, S; Horimoto, N; Nakano, H

2001-08-01

It is well known that 1/f characteristics in power spectral patterns exist in various biological factors including heart rate variability. In the present study, we tried to elucidate the diurnal variation in spectral properties of eye movement and heart rate variability in the human fetus at term, via continuous 24-h observation of both these parameters. Studied were five uncomplicated fetuses at term. We observed eye movement and fetal heart rate (FHR) with real-time ultrasound and Doppler cardiotocograph, respectively, and analyzed the diurnal change in spectral properties, using the maximum entropy method. In four of five cases, the slope values of power spectra for both eye movement frequency and FHR, ranging approximately between 0.5 and 1.8, indicated diurnal variation, where the slopes tended to have high values during the day and low values at night. These findings suggest that, in the human fetus at term, eye movement and FHR are under the control of a common central mechanism, and this center changes its complexity as seen through diurnal rhythm.

An eye movement pre-training fosters the comprehension of processes and functions in technical systems

PubMed Central

Skuballa, Irene T.; Fortunski, Caroline; Renkl, Alexander

2015-01-01

The main research goal of the present study was to investigate in how far pre-training eye movements can facilitate knowledge acquisition in multimedia (pre-training principle). We combined considerations from research on eye movement modeling and pre-training to design and test a non-verbal eye movement-based pre-training. Participants in the experimental condition watched an animated circle moving in close spatial resemblance to a static visualization of a solar plant accompanied by a narration in a subsequently presented learning environment. This training was expected to foster top-down processes as reflected in gaze behavior during the learning process and enhance knowledge acquisition. We compared two groups (N = 45): participants in the experimental condition received pre-training in a first step and processed the learning material in a second step, whereas the control group underwent the second step without any pre-training. The pre-training group outperformed the control group in their learning outcomes, particularly in knowledge about processes and functions of the solar plant. However, the superior learning outcomes in the pre-training group could not be explained by eye-movement patterns. Furthermore, the pre-training moderated the relationship between experienced stress and learning outcomes. In the control group, high stress levels hindered learning, which was not found for the pre-training group. On a delayed posttest participants were requested to draw a picture of the learning content. Despite a non-significant effect of training on the quality of drawings, the pre-training showed associations between learning outcomes at the first testing time and process-related aspects in the quality of their drawings. Overall, non-verbal pre-training is a successful instructional intervention to promote learning processes in novices although these processes did not directly reflect in learners' eye movement behavior during learning. PMID:26029138

Tonic and phasic phenomena underlying eye movements during sleep in the cat

PubMed Central

Márquez-Ruiz, Javier; Escudero, Miguel

2008-01-01

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep–wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep–wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now. PMID:18499729

Tonic and phasic phenomena underlying eye movements during sleep in the cat.

PubMed

Márquez-Ruiz, Javier; Escudero, Miguel

2008-07-15

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep-wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep-wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now.

Communication and control by listening: toward optimal design of a two-class auditory streaming brain-computer interface.

PubMed

Hill, N Jeremy; Moinuddin, Aisha; Häuser, Ann-Katrin; Kienzle, Stephan; Schalk, Gerwin

2012-01-01

Most brain-computer interface (BCI) systems require users to modulate brain signals in response to visual stimuli. Thus, they may not be useful to people with limited vision, such as those with severe paralysis. One important approach for overcoming this issue is auditory streaming, an approach whereby a BCI system is driven by shifts of attention between two simultaneously presented auditory stimulus streams. Motivated by the long-term goal of translating such a system into a reliable, simple yes-no interface for clinical usage, we aim to answer two main questions. First, we asked which of two previously published variants provides superior performance: a fixed-phase (FP) design in which the streams have equal period and opposite phase, or a drifting-phase (DP) design where the periods are unequal. We found FP to be superior to DP (p = 0.002): average performance levels were 80 and 72% correct, respectively. We were also able to show, in a pilot with one subject, that auditory streaming can support continuous control and neurofeedback applications: by shifting attention between ongoing left and right auditory streams, the subject was able to control the position of a paddle in a computer game. Second, we examined whether the system is dependent on eye movements, since it is known that eye movements and auditory attention may influence each other, and any dependence on the ability to move one's eyes would be a barrier to translation to paralyzed users. We discovered that, despite instructions, some subjects did make eye movements that were indicative of the direction of attention. However, there was no correlation, across subjects, between the reliability of the eye movement signal and the reliability of the BCI system, indicating that our system was configured to work independently of eye movement. Together, these findings are an encouraging step forward toward BCIs that provide practical communication and control options for the most severely paralyzed users.

Medications influencing central cholinergic pathways affect fixation stability, saccadic response time and associated eye movement dynamics during a temporally-cued visual reaction time task.

PubMed

Naicker, Preshanta; Anoopkumar-Dukie, Shailendra; Grant, Gary D; Modenese, Luca; Kavanagh, Justin J

2017-02-01

Anticholinergic medications largely exert their effects due to actions on the muscarinic receptor, which mediates the functions of acetylcholine in the peripheral and central nervous systems. In the central nervous system, acetylcholine plays an important role in the modulation of movement. This study investigated the effects of over-the-counter medications with varying degrees of central anticholinergic properties on fixation stability, saccadic response time and the dynamics associated with this eye movement during a temporally-cued visual reaction time task, in order to establish the significance of central cholinergic pathways in influencing eye movements during reaction time tasks. Twenty-two participants were recruited into the placebo-controlled, human double-blind, four-way crossover investigation. Eye tracking technology recorded eye movements while participants reacted to visual stimuli following temporally informative and uninformative cues. The task was performed pre-ingestion as well as 0.5 and 2 h post-ingestion of promethazine hydrochloride (strong centrally acting anticholinergic), hyoscine hydrobromide (moderate centrally acting anticholinergic), hyoscine butylbromide (anticholinergic devoid of central properties) and a placebo. Promethazine decreased fixation stability during the reaction time task. In addition, promethazine was the only drug to increase saccadic response time during temporally informative and uninformative cued trials, whereby effects on response time were more pronounced following temporally informative cues. Promethazine also decreased saccadic amplitude and increased saccadic duration during the temporally-cued reaction time task. Collectively, the results of the study highlight the significant role that central cholinergic pathways play in the control of eye movements during tasks that involve stimulus identification and motor responses following temporal cues.

Disrupted rapid eye movement sleep predicts poor declarative memory performance in post-traumatic stress disorder.

PubMed

Lipinska, Malgorzata; Timol, Ridwana; Kaminer, Debra; Thomas, Kevin G F

2014-06-01

Successful memory consolidation during sleep depends on healthy slow-wave and rapid eye movement sleep, and on successful transition across sleep stages. In post-traumatic stress disorder, sleep is disrupted and memory is impaired, but relations between these two variables in the psychiatric condition remain unexplored. We examined whether disrupted sleep, and consequent disrupted memory consolidation, is a mechanism underlying declarative memory deficits in post-traumatic stress disorder. We recruited three matched groups of participants: post-traumatic stress disorder (n = 16); trauma-exposed non-post-traumatic stress disorder (n = 15); and healthy control (n = 14). They completed memory tasks before and after 8 h of sleep. We measured sleep variables using sleep-adapted electroencephalography. Post-traumatic stress disorder-diagnosed participants experienced significantly less sleep efficiency and rapid eye movement sleep percentage, and experienced more awakenings and wake percentage in the second half of the night than did participants in the other two groups. After sleep, post-traumatic stress disorder-diagnosed participants retained significantly less information on a declarative memory task than controls. Rapid eye movement percentage, wake percentage and sleep efficiency correlated with retention of information over the night. Furthermore, lower rapid eye movement percentage predicted poorer retention in post-traumatic stress disorder-diagnosed individuals. Our results suggest that declarative memory consolidation is disrupted during sleep in post-traumatic stress disorder. These data are consistent with theories suggesting that sleep benefits memory consolidation via predictable neurobiological mechanisms, and that rapid eye movement disruption is more than a symptom of post-traumatic stress disorder. © 2014 European Sleep Research Society.

The eyes don't have it: lie detection and Neuro-Linguistic Programming.

PubMed

Wiseman, Richard; Watt, Caroline; ten Brinke, Leanne; Porter, Stephen; Couper, Sara-Louise; Rankin, Calum

2012-01-01

Proponents of Neuro-Linguistic Programming (NLP) claim that certain eye-movements are reliable indicators of lying. According to this notion, a person looking up to their right suggests a lie whereas looking up to their left is indicative of truth telling. Despite widespread belief in this claim, no previous research has examined its validity. In Study 1 the eye movements of participants who were lying or telling the truth were coded, but did not match the NLP patterning. In Study 2 one group of participants were told about the NLP eye-movement hypothesis whilst a second control group were not. Both groups then undertook a lie detection test. No significant differences emerged between the two groups. Study 3 involved coding the eye movements of both liars and truth tellers taking part in high profile press conferences. Once again, no significant differences were discovered. Taken together the results of the three studies fail to support the claims of NLP. The theoretical and practical implications of these findings are discussed.

The Eyes Don’t Have It: Lie Detection and Neuro-Linguistic Programming

PubMed Central

Wiseman, Richard; Watt, Caroline; ten Brinke, Leanne; Porter, Stephen; Couper, Sara-Louise; Rankin, Calum

2012-01-01

Proponents of Neuro-Linguistic Programming (NLP) claim that certain eye-movements are reliable indicators of lying. According to this notion, a person looking up to their right suggests a lie whereas looking up to their left is indicative of truth telling. Despite widespread belief in this claim, no previous research has examined its validity. In Study 1 the eye movements of participants who were lying or telling the truth were coded, but did not match the NLP patterning. In Study 2 one group of participants were told about the NLP eye-movement hypothesis whilst a second control group were not. Both groups then undertook a lie detection test. No significant differences emerged between the two groups. Study 3 involved coding the eye movements of both liars and truth tellers taking part in high profile press conferences. Once again, no significant differences were discovered. Taken together the results of the three studies fail to support the claims of NLP. The theoretical and practical implications of these findings are discussed. PMID:22808128

Development of the eye-movement response in the trainee radiologist

NASA Astrophysics Data System (ADS)

Wooding, David S.; Roberts, Geraint M.; Phillips-Hughes, Jane

1999-05-01

In order to explore the initial response of the visual system to radiological images in groups of individuals with increasing degrees of radiological training and experience, the locations of fixations made during visual inspection of digitized chest radiographs were examined for 4 groups of observers: 10 experienced radiologists, 9 first-year 'novice' radiologists, 11 'trainee' radiologists in the second and third years of their training, and 7 native controls. Each observer viewed 12 digitized chest radiographs (6 normal and 6 showing some abnormality) in a VDU for 8s each. Eye movements were recorded throughout and observers indicated via a button box whether they thought the radiograph to be normal or abnormal. A least squares index was utilized in order to quantify the similarity in fixation location between pairs of eye movement traces over the first 1.5 and 3 seconds of an inspection. The similarities thus produced were then averaged to give intra- and inter-group similarities in fixation location. The fixation locations of experienced radiologists were found to be highly similar as a group, as were those of the novices. While the fixation locations of controls showed less similarity, it was the fixations of trainees which were the least similar (i.e. showed the most variability) within their group. The fixation locations of novices showed a greater similarity to those of radiologists than those of controls, and a decreased similarity to those of controls than those of the controls themselves. However, rather than showing that the fixation locations of individuals become increasing similar to those of radiologists as training progresses, the data show that the more variable fixation locations of trainees are the least similar to those of radiologists than those of any of the groups, even the controls. Control observers examine every day images in a similar way and this is also true of radiological images. Experienced radiologists view radiological images in a similar way to each other, but their training has resulted in differences between them and controls. In becoming experienced radiologists, it appears that trainees may move through a developmental phase characterized by more idiosyncratic eye movements; their eye movements becoming less similar to controls or experienced radiologists than they were. With experience the eye movements of trainee radiologists may become more similar to both groups, but the transition of the trainee from novice to experienced radiologist is not a simple one: the change involves a period of some disorder.

Oculomotor control in children with fetal alcohol spectrum disorders assessed using a mobile eye-tracking laboratory.

PubMed

Green, C R; Mihic, A M; Brien, D C; Armstrong, I T; Nikkel, S M; Stade, B C; Rasmussen, C; Munoz, D P; Reynolds, J N

2009-03-01

Prenatal exposure to alcohol can result in a spectrum of adverse developmental outcomes, collectively termed fetal alcohol spectrum disorders (FASDs). This study evaluated deficits in sensory, motor and cognitive processing in children with FASD that can be identified using eye movement testing. Our study group was composed of 89 children aged 8-15 years with a diagnosis within the FASD spectrum [i.e. fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (pFAS), and alcohol-related neurodevelopmental disorder (ARND)], and 92 controls. Subjects looked either towards (prosaccade) or away from (antisaccade) a peripheral target that appeared on a computer monitor, and eye movements were recorded with a mobile, video-based eye tracker. We hypothesized that: (i) differences in the magnitude of deficits in eye movement control exist across the three diagnostic subgroups; and (ii) children with FASD display a developmental delay in oculomotor control. Children with FASD had increased saccadic reaction times (SRTs), increased intra-subject variability in SRTs, and increased direction errors in both the prosaccade and antisaccade tasks. Although development was associated with improvements across tasks, children with FASD failed to achieve age-matched control levels of performance at any of the ages tested. Moreover, children with ARND had faster SRTs and made fewer direction errors in the antisaccade task than children with pFAS or FAS, although all subgroups were different from controls. Our results demonstrate that eye tracking can be used as an objective measure of brain injury in FASD, revealing behavioral deficits in all three diagnostic subgroups independent of facial dysmorphology.

GazeParser: an open-source and multiplatform library for low-cost eye tracking and analysis.

PubMed

Sogo, Hiroyuki

2013-09-01

Eye movement analysis is an effective method for research on visual perception and cognition. However, recordings of eye movements present practical difficulties related to the cost of the recording devices and the programming of device controls for use in experiments. GazeParser is an open-source library for low-cost eye tracking and data analysis; it consists of a video-based eyetracker and libraries for data recording and analysis. The libraries are written in Python and can be used in conjunction with PsychoPy and VisionEgg experimental control libraries. Three eye movement experiments are reported on performance tests of GazeParser. These showed that the means and standard deviations for errors in sampling intervals were less than 1 ms. Spatial accuracy ranged from 0.7° to 1.2°, depending on participant. In gap/overlap tasks and antisaccade tasks, the latency and amplitude of the saccades detected by GazeParser agreed with those detected by a commercial eyetracker. These results showed that the GazeParser demonstrates adequate performance for use in psychological experiments.

Spontaneous improvement in oculomotor function of children with cerebral palsy.

PubMed

Ego, Caroline; Orban de Xivry, Jean-Jacques; Nassogne, Marie-Cécile; Yüksel, Demet; Lefèvre, Philippe

2014-11-20

Eye movements are essential to get a clear vision of moving objects. In the present study, we assessed quantitatively the oculomotor deficits of children with cerebral palsy (CP). We recorded eye movements of 51 children with cerebral palsy (aged 5-16 years) with relatively mild motor impairment and compared their performance with age-matched control and premature children. Overall eye movements of children with CP are unexpectedly close to those of controls even though some oculomotor parameters are biased by the side of hemiplegia. Importantly, the difference in performance between children with CP and controls decreases with age, demonstrating that the oculomotor function of children with CP develops as fast as or even faster than controls for some visual tracking parameters. That is, oculomotor function spontaneously improves over the course of childhood. This evolution highlights the ability of lesioned brain of children with CP to compensate for impaired motor function beyond what would be achieved by normal development on its own. Copyright © 2014 Elsevier Ltd. All rights reserved.

Using eye tracking to identify faking attempts during penile plethysmography assessment.

PubMed

Trottier, Dominique; Rouleau, Joanne-Lucine; Renaud, Patrice; Goyette, Mathieu

2014-01-01

Penile plethysmography (PPG) is considered the most rigorous method for sexual interest assessment. Nevertheless, it is subject to faking attempts by participants, which compromises the internal validity of the instrument. To date, various attempts have been made to limit voluntary control of sexual response during PPG assessments, without satisfactory results. This exploratory research examined eye-tracking technologies' ability to identify the presence of cognitive strategies responsible for erectile inhibition during PPG assessment. Eye movements and penile responses for 20 subjects were recorded while exploring animated human-like computer-generated stimuli in a virtual environment under three distinct viewing conditions: (a) the free visual exploration of a preferred sexual stimulus without erectile inhibition; (b) the viewing of a preferred sexual stimulus with erectile inhibition; and (c) the free visual exploration of a non-preferred sexual stimulus. Results suggest that attempts to control erectile responses generate specific eye-movement variations, characterized by a general deceleration of the exploration process and limited exploration of the erogenous zone. Findings indicate that recording eye movements can provide significant information on the presence of competing covert processes responsible for erectile inhibition. The use of eye-tracking technologies during PPG could therefore lead to improved internal validity of the plethysmographic procedure.

Saccade Preparation Is Required for Exogenous Attention but Not Endogenous Attention or IOR

ERIC Educational Resources Information Center

Smith, Daniel T.; Schenk, Thomas; Rorden, Chris

2012-01-01

Covert attention is tightly coupled with the control of eye movements, but there is controversy about how tight this coupling is. The premotor theory of attention proposes that activation of the eye movement system is necessary to produce shifts of attention. In this study, we experimentally prevented healthy participants from planning or…

Randomized, Controlled Trial of CBT Training for PTSD Providers

DTIC Science & Technology

2013-10-01

and Therapy, 47, 902-909. Shapiro, F. (2001). Eye movement desensitization and reprocessing ( EMDR ): Basic principles...Hopper, E. K., Korn, D. L., & Simpson, W. B. (2007). A randomized clinical trial of eye movement desensitization and reprocessing ( EMDR ), fluoxetine...Josef Ruzek, Ph.D. CONTRACTING ORGANIZATION: Palo Alto Institute for Research and Education Palo Alto, CA 94304 REPORT

Binocular fusion and invariant category learning due to predictive remapping during scanning of a depthful scene with eye movements

PubMed Central

Grossberg, Stephen; Srinivasan, Karthik; Yazdanbakhsh, Arash

2015-01-01

How does the brain maintain stable fusion of 3D scenes when the eyes move? Every eye movement causes each retinal position to process a different set of scenic features, and thus the brain needs to binocularly fuse new combinations of features at each position after an eye movement. Despite these breaks in retinotopic fusion due to each movement, previously fused representations of a scene in depth often appear stable. The 3D ARTSCAN neural model proposes how the brain does this by unifying concepts about how multiple cortical areas in the What and Where cortical streams interact to coordinate processes of 3D boundary and surface perception, spatial attention, invariant object category learning, predictive remapping, eye movement control, and learned coordinate transformations. The model explains data from single neuron and psychophysical studies of covert visual attention shifts prior to eye movements. The model further clarifies how perceptual, attentional, and cognitive interactions among multiple brain regions (LGN, V1, V2, V3A, V4, MT, MST, PPC, LIP, ITp, ITa, SC) may accomplish predictive remapping as part of the process whereby view-invariant object categories are learned. These results build upon earlier neural models of 3D vision and figure-ground separation and the learning of invariant object categories as the eyes freely scan a scene. A key process concerns how an object's surface representation generates a form-fitting distribution of spatial attention, or attentional shroud, in parietal cortex that helps maintain the stability of multiple perceptual and cognitive processes. Predictive eye movement signals maintain the stability of the shroud, as well as of binocularly fused perceptual boundaries and surface representations. PMID:25642198

Binocular fusion and invariant category learning due to predictive remapping during scanning of a depthful scene with eye movements.

PubMed

Grossberg, Stephen; Srinivasan, Karthik; Yazdanbakhsh, Arash

2014-01-01

How does the brain maintain stable fusion of 3D scenes when the eyes move? Every eye movement causes each retinal position to process a different set of scenic features, and thus the brain needs to binocularly fuse new combinations of features at each position after an eye movement. Despite these breaks in retinotopic fusion due to each movement, previously fused representations of a scene in depth often appear stable. The 3D ARTSCAN neural model proposes how the brain does this by unifying concepts about how multiple cortical areas in the What and Where cortical streams interact to coordinate processes of 3D boundary and surface perception, spatial attention, invariant object category learning, predictive remapping, eye movement control, and learned coordinate transformations. The model explains data from single neuron and psychophysical studies of covert visual attention shifts prior to eye movements. The model further clarifies how perceptual, attentional, and cognitive interactions among multiple brain regions (LGN, V1, V2, V3A, V4, MT, MST, PPC, LIP, ITp, ITa, SC) may accomplish predictive remapping as part of the process whereby view-invariant object categories are learned. These results build upon earlier neural models of 3D vision and figure-ground separation and the learning of invariant object categories as the eyes freely scan a scene. A key process concerns how an object's surface representation generates a form-fitting distribution of spatial attention, or attentional shroud, in parietal cortex that helps maintain the stability of multiple perceptual and cognitive processes. Predictive eye movement signals maintain the stability of the shroud, as well as of binocularly fused perceptual boundaries and surface representations.

Eye-movements and ongoing task processing.

PubMed

Burke, David T; Meleger, Alec; Schneider, Jeffrey C; Snyder, Jim; Dorvlo, Atsu S S; Al-Adawi, Samir

2003-06-01

This study tests the relation between eye-movements and thought processing. Subjects were given specific modality tasks (visual, gustatory, kinesthetic) and assessed on whether they responded with distinct eye-movements. Some subjects' eye-movements reflected ongoing thought processing. Instead of a universal pattern, as suggested by the neurolinguistic programming hypothesis, this study yielded subject-specific idiosyncratic eye-movements across all modalities. Included is a discussion of the neurolinguistic programming hypothesis regarding eye-movements and its implications for the eye-movement desensitization and reprocessing theory.

The influence of action video game playing on eye movement behaviour during visual search in abstract, in-game and natural scenes.

PubMed

Azizi, Elham; Abel, Larry A; Stainer, Matthew J

2017-02-01

Action game playing has been associated with several improvements in visual attention tasks. However, it is not clear how such changes might influence the way we overtly select information from our visual world (i.e. eye movements). We examined whether action-video-game training changed eye movement behaviour in a series of visual search tasks including conjunctive search (relatively abstracted from natural behaviour), game-related search, and more naturalistic scene search. Forty nongamers were trained in either an action first-person shooter game or a card game (control) for 10 hours. As a further control, we recorded eye movements of 20 experienced action gamers on the same tasks. The results did not show any change in duration of fixations or saccade amplitude either from before to after the training or between all nongamers (pretraining) and experienced action gamers. However, we observed a change in search strategy, reflected by a reduction in the vertical distribution of fixations for the game-related search task in the action-game-trained group. This might suggest learning the likely distribution of targets. In other words, game training only skilled participants to search game images for targets important to the game, with no indication of transfer to the more natural scene search. Taken together, these results suggest no modification in overt allocation of attention. Either the skills that can be trained with action gaming are not powerful enough to influence information selection through eye movements, or action-game-learned skills are not used when deciding where to move the eyes.

Interactions between gaze-evoked blinks and gaze shifts in monkeys.

PubMed

Gandhi, Neeraj J

2012-02-01

Rapid eyelid closure, or a blink, often accompanies head-restrained and head-unrestrained gaze shifts. This study examines the interactions between such gaze-evoked blinks and gaze shifts in monkeys. Blink probability increases with gaze amplitude and at a faster rate for head-unrestrained movements. Across animals, blink likelihood is inversely correlated with the average gaze velocity of large-amplitude control movements. Gaze-evoked blinks induce robust perturbations in eye velocity. Peak and average velocities are reduced, duration is increased, but accuracy is preserved. The temporal features of the perturbation depend on factors such as the time of blink relative to gaze onset, inherent velocity kinematics of control movements, and perhaps initial eye-in-head position. Although variable across animals, the initial effect is a reduction in eye velocity, followed by a reacceleration that yields two or more peaks in its waveform. Interestingly, head velocity is not attenuated; instead, it peaks slightly later and with a larger magnitude. Gaze latency is slightly reduced on trials with gaze-evoked blinks, although the effect was more variable during head-unrestrained movements; no reduction in head latency is observed. Preliminary data also demonstrate a similar perturbation of gaze-evoked blinks during vertical saccades. The results are compared with previously reported effects of reflexive blinks (evoked by air-puff delivered to one eye or supraorbital nerve stimulation) and discussed in terms of effects of blinks on saccadic suppression, neural correlates of the altered eye velocity signals, and implications on the hypothesis that the attenuation in eye velocity is produced by a head movement command.

Effects of Peripheral Visual Field Loss on Eye Movements During Visual Search

PubMed Central

Wiecek, Emily; Pasquale, Louis R.; Fiser, Jozsef; Dakin, Steven; Bex, Peter J.

2012-01-01

Natural vision involves sequential eye movements that bring the fovea to locations selected by peripheral vision. How peripheral visual field loss (PVFL) affects this process is not well understood. We examine how the location and extent of PVFL affects eye movement behavior in a naturalistic visual search task. Ten patients with PVFL and 13 normally sighted subjects with full visual fields (FVF) completed 30 visual searches monocularly. Subjects located a 4° × 4° target, pseudo-randomly selected within a 26° × 11° natural image. Eye positions were recorded at 50 Hz. Search duration, fixation duration, saccade size, and number of saccades per trial were not significantly different between PVFL and FVF groups (p > 0.1). A χ2 test showed that the distributions of saccade directions for PVFL and FVL subjects were significantly different in 8 out of 10 cases (p < 0.01). Humphrey Visual Field pattern deviations for each subject were compared with the spatial distribution of eye movement directions. There were no significant correlations between saccade directional bias and visual field sensitivity across the 10 patients. Visual search performance was not significantly affected by PVFL. An analysis of eye movement directions revealed patients with PVFL show a biased directional distribution that was not directly related to the locus of vision loss, challenging feed-forward models of eye movement control. Consequently, many patients do not optimally compensate for visual field loss during visual search. PMID:23162511

Spontaneous eye blinks are entrained by finger tapping.

PubMed

Cong, D-K; Sharikadze, M; Staude, G; Deubel, H; Wolf, W

2010-02-01

We studied the mutual cross-talk between spontaneous eye blinks and continuous, self-paced unimanual and bimanual tapping. Both types of motor activities were analyzed with regard to their time-structure in synchronization-continuation tapping tasks which involved different task instructions, namely "standard" finger tapping (Experiment 1), "strong" tapping (Experiment 2) requiring more forceful finger movements, and "impulse-like" tapping (Experiment 3) where upward-downward finger movements had to be very fast. In a further control condition (Experiment 4), tapping was omitted altogether. The results revealed a prominent entrainment of spontaneous blink behavior by the manual tapping, with bimanual tapping being more effective than unimanual tapping, and with the "strong" and "impulse-like" tapping showing the largest effects on blink timing. Conversely, we found no significant effects of the tapping on the timing of the eye blinks across all experiments. The findings suggest a functional overlap of the motor control structures responsible for voluntary, rhythmic finger movements and eye blinking behavior.

Spatial and Temporal Eye–Hand Coordination Relies on the Parietal Reach Region

PubMed Central

Hauschild, Markus; Wilke, Melanie; Andersen, Richard A.

2014-01-01

Coordinated eye movements are crucial for precision control of our hands. A commonly believed neural mechanism underlying eye–hand coordination is interaction between the neural networks controlling each effector, exchanging, and matching information, such as movement target location and onset time. Alternatively, eye–hand coordination may result simply from common inputs to independent eye and hand control pathways. Thus far, it remains unknown whether and where either of these two possible mechanisms exists. A candidate location for the former mechanism, interpathway communication, includes the posterior parietal cortex (PPC) where distinct effector-specific areas reside. If the PPC were within the network for eye–hand coordination, perturbing it would affect both eye and hand movements that are concurrently planned. In contrast, if eye–hand coordination arises solely from common inputs, perturbing one effector pathway, e.g., the parietal reach region (PRR), would not affect the other effector. To test these hypotheses, we inactivated part of PRR in the macaque, located in the medial bank of the intraparietal sulcus encompassing the medial intraparietal area and area 5V. When each effector moved alone, PRR inactivation shortened reach but not saccade amplitudes, compatible with the known reach-selective activity of PRR. However, when both effectors moved concurrently, PRR inactivation shortened both reach and saccade amplitudes, and decoupled their reaction times. Therefore, consistent with the interpathway communication hypothesis, we propose that the planning of concurrent eye and hand movements causes the spatial information in PRR to influence the otherwise independent eye control pathways, and that their temporal coupling requires an intact PRR. PMID:25232123

Controlling Posture and Vergence Eye Movements in Quiet Stance: Effects of Thin Plantar Inserts

PubMed Central

Foisy, A.; Gaertner, C.; Matheron, E.; Kapoula, Z.

2015-01-01

The purpose of this study was to assess properties of vergence and saccade eye movements as well as posture in quiet stance, and the effects of thin plantar inserts upon postural and oculomotor control. The performances of 36 young healthy subjects were recorded by a force platform and an eye tracker in three testing conditions: without plantar stimulation, with a 3 millimetre-thick plantar insert, either a Medial or a Lateral Arch Support (MAS / LAS). The results showed a decrease of the Surface and Variance of Speed and a more posterior position of the CoP with either stimulation compared with the control condition. The fractal analysis showed a decrease with MAS. Wavelet analysis in the time-frequency domain revealed an increase in the Cancelling Time of the low frequency band with MAS. These results suggest a better stability for a lower energy cost. Concerning eye movements, the inserts influenced only vergence (not saccades): MAS caused an increase of the phasic amplitude of divergence, and conversely a decrease of the tonic amplitude. In contrast, LAS caused an increase of the tonic amplitude of convergence. Thus, MAS renders divergence less visually driven, while LAS renders convergence more visually driven. We conclude that the CNS uses the podal signal for both postural and vergence control via specific mechanisms. Plantar inserts have an influence upon posture and vergence movements in a different way according to the part of the foot sole being stimulated. These results can be useful to clinicians interested in foot or eye. PMID:26637132

Semantic guidance of eye movements in real-world scenes

PubMed Central

Hwang, Alex D.; Wang, Hsueh-Cheng; Pomplun, Marc

2011-01-01

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying Latent Semantic Analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects’ gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects’ eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. PMID:21426914

Semantic guidance of eye movements in real-world scenes.

PubMed

Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc

2011-05-25

The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cervico-ocular coordination during neck rotation is distorted in people with whiplash-associated disorders.

PubMed

Bexander, Catharina S M; Hodges, Paul W

2012-03-01

People with whiplash-associated disorders (WAD) not only suffer from neck/head pain, but commonly report deficits in eye movement control. Recent work has highlighted a strong relationship between eye and neck muscle activation in pain-free subjects. It is possible that WAD may disrupt the intricate coordination between eye and neck movement. Electromyographic activity (EMG) of muscles that rotate the cervical spine to the right (left sternocleidomastoid, right obliquus capitis inferior (OI), right splenius capitis (SC) and right multifidus (MF)) was recorded in nine people with chronic WAD. Cervical rotation was performed with five gaze conditions involving different gaze directions relative to cervical rotation. The relationship between eye position/movement and neck muscle activity was contrasted with previous observations from pain-free controls. Three main differences were observed in WAD. First, the superficial muscle SC was active with both directions of cervical rotation in contrast to activity only with right rotation in pain-free controls. Second, activity of OI and MF varied between directions of cervical rotation, unlike the non-direction-specific activity in controls. Third, the effect of horizontal gaze direction on neck muscle EMG was augmented compared to controls. These observations provide evidence of redistribution of activity between neck muscles during cervical rotation and increased interaction between eye and neck muscle activity in people with WAD. These changes in cervico-ocular coordination may underlie clinical symptoms reported by people with WAD that involve visual deficits and changes in function during cervical rotation such as postural control.

Coordinated Control of Three-Dimensional Components of Smooth Pursuit to Rotating and Translating Textures.

PubMed

Edinger, Janick; Pai, Dinesh K; Spering, Miriam

2017-01-01

The neural control of pursuit eye movements to visual textures that simultaneously translate and rotate has largely been neglected. Here we propose that pursuit of such targets-texture pursuit-is a fully three-dimensional task that utilizes all three degrees of freedom of the eye, including torsion. Head-fixed healthy human adults (n = 8) tracked a translating and rotating random dot pattern, shown on a computer monitor, with their eyes. Horizontal, vertical, and torsional eye positions were recorded with a head-mounted eye tracker. The torsional component of pursuit is a function of the rotation of the texture, aligned with its visual properties. We observed distinct behaviors between those trials in which stimulus rotation was in the same direction as that of a rolling ball ("natural") in comparison to those with the opposite rotation ("unnatural"): Natural rotation enhanced and unnatural rotation reversed torsional velocity during pursuit, as compared to torsion triggered by a nonrotating random dot pattern. Natural rotation also triggered pursuit with a higher horizontal velocity gain and fewer and smaller corrective saccades. Furthermore, we show that horizontal corrective saccades are synchronized with torsional corrective saccades, indicating temporal coupling of horizontal and torsional saccade control. Pursuit eye movements have a torsional component that depends on the visual stimulus. Horizontal and torsional eye movements are separated in the motor periphery. Our findings suggest that translational and rotational motion signals might be coordinated in descending pursuit pathways.

Model simulation studies to clarify the effect on saccadic eye movements of initial condition velocities set by the Vestibular Ocular Reflex (VOR)

NASA Technical Reports Server (NTRS)

Nam, M. H.; Winters, J. M.; Stark, L.

1981-01-01

Voluntary active head rotations produced vestibulo-ocular reflex eye movements (VOR) with the subject viewing a fixation target. When this target jumped, the size of the refixation saccades were a function of the ongoing initial velocity of the eye. Saccades made against the VOR were larger in magnitude. Simulation of a reciprocally innervated model eye movement provided results comparable to the experimental data. Most of the experimental effect appeared to be due to linear summation for saccades of 5 and 10 degree magnitude. For small saccades of 2.5 degrees, peripheral nonlinear interaction of state variables in the neuromuscular plant also played a role as proven by comparable behavior in the simulated model with known controller signals.

Eye Movement Control during Reading: II. Frequency of Refixating a Word. Technical Report No. 469.

ERIC Educational Resources Information Center

McConkie, G. W.; And Others

As part of a series of studies describing the oculomotor behavior of skilled readers, a study investigated whether a word refixation curve exists. Subjects, 66 college students fixating over 40,000 times, read lines of text from a computer screen and were instructed to read for meaning without regard to errors. Results of eye movement control…

Direct Lexical Control of Eye Movements in Reading: Evidence from a Survival Analysis of Fixation Durations

ERIC Educational Resources Information Center

Reingold, Eyal M.; Reichle, Erik D.; Glaholt, Mackenzie G.; Sheridan, Heather

2012-01-01

Participants' eye movements were monitored in an experiment that manipulated the frequency of target words (high vs. low) as well as their availability for parafoveal processing during fixations on the pre-target word (valid vs. invalid preview). The influence of the word-frequency by preview validity manipulation on the distributions of first…

Reading Ahead: Adult Music Students' Eye Movements in Temporally Controlled Performances of a Children's Song

ERIC Educational Resources Information Center

Penttinen, Marjaana; Huovinen, Erkki; Ylitalo, Anna-Kaisa

2015-01-01

In the present study, education majors minoring in music education (n = 24) and music performance majors (n =14) read and performed the original version and melodically altered versions of a simple melody in a given tempo. Eye movements during music reading and piano performances were recorded. Errorless trials were analyzed to explore the…

The Efficacy of Eye Movement Desensitization and Reprocessing Therapy Technique in the Treatment of Test Anxiety of College Students.

ERIC Educational Resources Information Center

Enright, Matthew; Baldo, Tracy D.; Wykes, Scott D.

2000-01-01

Explores the efficacy of eye movement desensitization and reprocessing (EMDR) in the treatment of test anxiety. Thirty-five college students with test anxiety were assigned to either a treatment or delayed treatment control group. EMDR was shown to be effective in reducing overall test anxiety as well as "emotionality" and…

Low frequency rTMS over posterior parietal cortex impairs smooth pursuit eye tracking.

PubMed

Hutton, Samuel B; Weekes, Brendan S

2007-11-01

The role of the posterior parietal cortex in smooth pursuit eye movements remains unclear. We used low frequency repetitive transcranial magnetic stimulation (rTMS) to study the cognitive and neural systems involved in the control of smooth pursuit eye movements. Eighteen participants were tested on two separate occasions. On each occasion we measured smooth pursuit eye tracking before and after 6 min of 1 Hz rTMS delivered at 90% of motor threshold. Low frequency rTMS over the posterior parietal cortex led to a significant reduction in smooth pursuit velocity gain, whereas rTMS over the motor cortex had no effect on gain. We conclude that low frequency offline rTMS is a potentially useful tool with which to explore the cortical systems involved in oculomotor control.

The relationship between eye movements and subsequent recognition: Evidence from individual differences and amnesia.

PubMed

Olsen, Rosanna K; Sebanayagam, Vinoja; Lee, Yunjo; Moscovitch, Morris; Grady, Cheryl L; Rosenbaum, R Shayna; Ryan, Jennifer D

2016-12-01

There is consistent agreement regarding the positive relationship between cumulative eye movement sampling and subsequent recognition, but the role of the hippocampus in this sampling behavior is currently unknown. It is also unclear whether the eye movement repetition effect, i.e., fewer fixations to repeated, compared to novel, stimuli, depends on explicit recognition and/or an intact hippocampal system. We investigated the relationship between cumulative sampling, the eye movement repetition effect, subsequent memory, and the hippocampal system. Eye movements were monitored in a developmental amnesic case (H.C.), whose hippocampal system is compromised, and in a group of typically developing participants while they studied single faces across multiple blocks. The faces were studied from the same viewpoint or different viewpoints and were subsequently tested with the same or different viewpoint. Our previous work suggested that hippocampal representations support explicit recognition for information that changes viewpoint across repetitions (Olsen et al., 2015). Here, examination of eye movements during encoding indicated that greater cumulative sampling was associated with better memory among controls. Increased sampling, however, was not associated with better explicit memory in H.C., suggesting that increased sampling only improves memory when the hippocampal system is intact. The magnitude of the repetition effect was not correlated with cumulative sampling, nor was it related reliably to subsequent recognition. These findings indicate that eye movements collect information that can be used to strengthen memory representations that are later available for conscious remembering, whereas eye movement repetition effects reflect a processing change due to experience that does not necessarily reflect a memory representation that is available for conscious appraisal. Lastly, H.C. demonstrated a repetition effect for fixed viewpoint faces but not for variable viewpoint faces, which suggests that repetition effects are differentially supported by neocortical and hippocampal systems, depending upon the representational nature of the underlying memory trace. Copyright © 2016 Elsevier Ltd. All rights reserved.

Eye movement training is most effective when it involves a task-relevant sensorimotor decision.

PubMed

Fooken, Jolande; Lalonde, Kathryn M; Mann, Gurkiran K; Spering, Miriam

2018-04-01

Eye and hand movements are closely linked when performing everyday actions. We conducted a perceptual-motor training study to investigate mutually beneficial effects of eye and hand movements, asking whether training in one modality benefits performance in the other. Observers had to predict the future trajectory of a briefly presented moving object, and intercept it at its assumed location as accurately as possible with their finger. Eye and hand movements were recorded simultaneously. Different training protocols either included eye movements or a combination of eye and hand movements with or without external performance feedback. Eye movement training did not transfer across modalities: Irrespective of feedback, finger interception accuracy and precision improved after training that involved the hand, but not after isolated eye movement training. Conversely, eye movements benefited from hand movement training or when external performance feedback was given, thus improving only when an active interceptive task component was involved. These findings indicate only limited transfer across modalities. However, they reveal the importance of creating a training task with an active sensorimotor decision to improve the accuracy and precision of eye and hand movements.

Relationships between Eye Movements during Sentence Reading Comprehension, Word Spelling and Reading, and DTI and fmri Connectivity In Students with and without Dysgraphia or Dyslexia

PubMed Central

Yagle, Kevin; Richards, Todd; Askren, Katie; Mestre, Zoe; Beers, Scott; Abbott, Robert; Nagy, William; Boord, Peter; Berninger, Virginia

2017-01-01

While eye movements were recorded and brains scanned, 29 children with and without specific learning disabilities (SLDs) decided if sentences they read (half with only correctly spelled words and half with homonym foils) were meaningful. Significant main effects were found for diagnostic groups (non-SLD control, dysgraphia control, and dyslexia) in total fixation (dwell) time, total number of fixations, and total regressions in during saccades; the dyslexia group had longer and more fixations and made more regressions in during saccades than either control group. The dyslexia group also differed from both control groups in (a) fractional anisotropy in left optic radiation and (b) silent word reading fluency on a task in which surrounding letters can be distracting, consistent with Rayner's selective attention dyslexia model. Different profiles for non-SLD control, dysgraphia, and dyslexia groups were identified in correlations between total fixation time, total number of fixations, regressions in during saccades, magnitude of gray matter connectivity during the fMRI sentence reading comprehension from left occipital temporal cortex seed with right BA44 and from left inferior frontal gyrus with right inferior frontoccipital fasciculus, and normed word-specific spelling and silent word reading fluency measures. The dysgraphia group was more likely than the non-SLD control or dyslexia groups to show negative correlations between eye movement outcomes and sentences containing incorrect homonym foils. Findings are discussed in reference to a systems approach in future sentence reading comprehension research that integrates eye movement, brain, and literacy measures. PMID:28936361

Relationships between Eye Movements during Sentence Reading Comprehension, Word Spelling and Reading, and DTI and fmri Connectivity In Students with and without Dysgraphia or Dyslexia.

PubMed

Yagle, Kevin; Richards, Todd; Askren, Katie; Mestre, Zoe; Beers, Scott; Abbott, Robert; Nagy, William; Boord, Peter; Berninger, Virginia

2017-01-01

While eye movements were recorded and brains scanned, 29 children with and without specific learning disabilities (SLDs) decided if sentences they read (half with only correctly spelled words and half with homonym foils) were meaningful. Significant main effects were found for diagnostic groups (non-SLD control, dysgraphia control, and dyslexia) in total fixation (dwell) time, total number of fixations, and total regressions in during saccades; the dyslexia group had longer and more fixations and made more regressions in during saccades than either control group. The dyslexia group also differed from both control groups in (a) fractional anisotropy in left optic radiation and (b) silent word reading fluency on a task in which surrounding letters can be distracting, consistent with Rayner's selective attention dyslexia model. Different profiles for non-SLD control, dysgraphia, and dyslexia groups were identified in correlations between total fixation time, total number of fixations, regressions in during saccades, magnitude of gray matter connectivity during the fMRI sentence reading comprehension from left occipital temporal cortex seed with right BA44 and from left inferior frontal gyrus with right inferior frontoccipital fasciculus, and normed word-specific spelling and silent word reading fluency measures. The dysgraphia group was more likely than the non-SLD control or dyslexia groups to show negative correlations between eye movement outcomes and sentences containing incorrect homonym foils. Findings are discussed in reference to a systems approach in future sentence reading comprehension research that integrates eye movement, brain, and literacy measures.

Design, simulation and evaluation of uniform magnetic field systems for head-free eye movement recordings with scleral search coils.

PubMed

Eibenberger, Karin; Eibenberger, Bernhard; Rucci, Michele

2016-08-01

The precise measurement of eye movements is important for investigating vision, oculomotor control and vestibular function. The magnetic scleral search coil technique is one of the most precise measurement techniques for recording eye movements with very high spatial (≈ 1 arcmin) and temporal (>kHz) resolution. The technique is based on measuring voltage induced in a search coil through a large magnetic field. This search coil is embedded in a contact lens worn by a human subject. The measured voltage is in direct relationship to the orientation of the eye in space. This requires a magnetic field with a high homogeneity in the center, since otherwise the field inhomogeneity would give the false impression of a rotation of the eye due to a translational movement of the head. To circumvent this problem, a bite bar typically restricts head movement to a minimum. However, the need often emerges to precisely record eye movements under natural viewing conditions. To this end, one needs a uniform magnetic field that is uniform over a large area. In this paper, we present the numerical and finite element simulations of the magnetic flux density of different coil geometries that could be used for search coil recordings. Based on the results, we built a 2.2 × 2.2 × 2.2 meter coil frame with a set of 3 × 4 coils to generate a 3D magnetic field and compared the measured flux density with our simulation results. In agreement with simulation results, the system yields a highly uniform field enabling high-resolution recordings of eye movements.

Effects of emotionally charged sounds in schizophrenia patients using exploratory eye movements: comparison with healthy subjects.

PubMed

Ishii, Youhei; Morita, Kiichiro; Shouji, Yoshihisa; Nakashima, Youko; Uchimura, Naohisa

2010-02-01

Emotion-associated sounds have been suggested to exert important effects upon human personal relationships. The present study was aimed to characterize the effects of the sounds of crying or laughing on visual cognitive function in schizophrenia patients. We recorded exploratory eye movements in 24 schizophrenia patients (mean age, 27.0 +/- 6.1 years; 14 male, 10 female) and age-matched controls. The total eye scanning length (TESL) and total number of gaze points in the left (left TNGP) and right (right TNGP) visual fields of the screen and the number of researching areas (NRA) were determined using eye-mark recording in the presence/absence of emotionally charged sounds. Controls' TESL for smiling pictures was longer than that for crying pictures irrespective of sounds. Patients' TESL for smiling pictures, however, was shorter than for crying pictures irrespective of the sounds. The left TNGP for smiling pictures was lower in patients than controls independent of sound. Importantly, the right TNGP was significantly larger with laughing sounds than in the absence of sound. In controls, the NRA for smiling pictures was significantly greater than for crying pictures irrespective of sound. Patient NRA did not significantly differ between smiling and crying pictures irrespective of sound. Eye movements in schizophrenia patients' left field for smiling pictures associated with laughing sounds particularly differed from those in controls, suggesting impaired visual cognitive function associated with positive emotion, also involving pleasure-related sounds, in schizophrenia.

Chronic Organic Solvent Exposure Changes Visual Tracking in Men and Women.

PubMed

de Oliveira, Ana R; Campos Neto, Armindo de Arruda; Bezerra de Medeiros, Paloma C; de Andrade, Michael J O; Dos Santos, Natanael A

2017-01-01

Organic solvents can change CNS sensory and motor function. Eye-movement analyses can be important tools when investigating the neurotoxic changes that result from chronic organic solvent exposure. The current research measured the eye-movement patterns of men and women with and without histories of chronic organic solvent exposure. A total of 44 volunteers between 18 and 41 years old participated in this study; 22 were men (11 exposed and 11 controls), and 22 were women (11 exposed and 11 controls). Eye movement was evaluated using a 250-Hz High-Speed Video Eye Tracker Toolbox (Cambridge Research Systems) via an image of a maze. Specific body indices of exposed and non-exposed men and women were measured with an Inbody 720 to determine whether the differences in eye-movement patterns were associated with body composition. The data were analyzed using IBM SPSS Statistics version 20.0.0. The results indicated that exposed adults showed significantly more fixations ( t = 3.82; p = 0.001; r = 0.51) and longer fixations ( t = 4.27; p = 0.001, r = 0.54) than their non-exposed counterparts. Comparisons within men (e.g., exposed and non-exposed) showed significant differences in the number of fixations ( t = 2.21; p = 0.04; r = 0.20) and duration of fixations ( t = 3.29; p = 0.001; r = 0.35). The same was true for exposed vs. non-exposed women, who showed significant differences in the number of fixations ( t = 3.10; p = 0.001; r = 0.32) and fixation durations ( t = 2.76; p = 0.01; r = 0.28). However, the results did not show significant differences between exposed women and men in the number and duration of fixations. No correlations were found between eye-movement pattern and body composition measures ( p > 0.05). These results suggest that chronic organic solvent exposure affects eye movements, regardless of sex and body composition, and that eye tracking contributes to the investigation of the visual information processing disorders acquired by workers exposed to organic solvents.

Ictal SPECT in patients with rapid eye movement sleep behaviour disorder.

PubMed

Mayer, Geert; Bitterlich, Marion; Kuwert, Torsten; Ritt, Philipp; Stefan, Hermann

2015-05-01

Rapid eye movement sleep behaviour disorder is a rapid eye movement parasomnia clinically characterized by acting out dreams due to disinhibition of muscle tone in rapid eye movement sleep. Up to 80-90% of the patients with rapid eye movement sleep behaviour disorder develop neurodegenerative disorders within 10-15 years after symptom onset. The disorder is reported in 45-60% of all narcoleptic patients. Whether rapid eye movement sleep behaviour disorder is also a predictor for neurodegeneration in narcolepsy is not known. Although the pathophysiology causing the disinhibition of muscle tone in rapid eye movement sleep behaviour disorder has been studied extensively in animals, little is known about the mechanisms in humans. Most of the human data are from imaging or post-mortem studies. Recent studies show altered functional connectivity between substantia nigra and striatum in patients with rapid eye movement sleep behaviour disorder. We were interested to study which regions are activated in rapid eye movement sleep behaviour disorder during actual episodes by performing ictal single photon emission tomography. We studied one patient with idiopathic rapid eye movement sleep behaviour disorder, one with Parkinson's disease and rapid eye movement sleep behaviour disorder, and two patients with narcolepsy and rapid eye movement sleep behaviour disorder. All patients underwent extended video polysomnography. The tracer was injected after at least 10 s of consecutive rapid eye movement sleep and 10 s of disinhibited muscle tone accompanied by movements registered by an experienced sleep technician. Ictal single photon emission tomography displayed the same activation in the bilateral premotor areas, the interhemispheric cleft, the periaqueductal area, the dorsal and ventral pons and the anterior lobe of the cerebellum in all patients. Our study shows that in patients with Parkinson's disease and rapid eye movement sleep behaviour disorder-in contrast to wakefulness-the neural activity generating movement during episodes of rapid eye movement sleep behaviour disorder bypasses the basal ganglia, a mechanism that is shared by patients with idiopathic rapid eye movement sleep behaviour disorder and narcolepsy patients with rapid eye movement sleep behaviour disorder. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

How strongly do word reading times and lexical decision times correlate? Combining data from eye movement corpora and megastudies.

PubMed

Kuperman, Victor; Drieghe, Denis; Keuleers, Emmanuel; Brysbaert, Marc

2013-01-01

We assess the amount of shared variance between three measures of visual word recognition latencies: eye movement latencies, lexical decision times, and naming times. After partialling out the effects of word frequency and word length, two well-documented predictors of word recognition latencies, we see that 7-44% of the variance is uniquely shared between lexical decision times and naming times, depending on the frequency range of the words used. A similar analysis of eye movement latencies shows that the percentage of variance they uniquely share either with lexical decision times or with naming times is much lower. It is 5-17% for gaze durations and lexical decision times in studies with target words presented in neutral sentences, but drops to 0.2% for corpus studies in which eye movements to all words are analysed. Correlations between gaze durations and naming latencies are lower still. These findings suggest that processing times in isolated word processing and continuous text reading are affected by specific task demands and presentation format, and that lexical decision times and naming times are not very informative in predicting eye movement latencies in text reading once the effect of word frequency and word length are taken into account. The difference between controlled experiments and natural reading suggests that reading strategies and stimulus materials may determine the degree to which the immediacy-of-processing assumption and the eye-mind assumption apply. Fixation times are more likely to exclusively reflect the lexical processing of the currently fixated word in controlled studies with unpredictable target words rather than in natural reading of sentences or texts.

Eye Carduino: A Car Control System using Eye Movements

NASA Astrophysics Data System (ADS)

Kumar, Arjun; Nagaraj, Disha; Louzardo, Joel; Hegde, Rajeshwari

2011-12-01

Modern automotive systems are rapidly becoming highly of transportation, but can be a web integrated media centre. This paper explains the implementation of a vehicle control defined and characterized by embedded electronics and software. With new technologies, the vehicle industry is facing new opportunities and also new challenges. Electronics have improved the performance of vehicles and at the same time, new more complex applications are introduced. Examples of high level applications include adaptive cruise control and electronic stability programs (ESP). Further, a modern vehicle does not have to be merely a means using only eye movements. The EyeWriter's native hardware and software work to return the co-ordinates of where the user is looking. These co-ordinates are then used to control the car. A centre-point is defined on the screen. The higher on the screen the user's gaze is, the faster the car will accelerate. Braking is done by looking below centre. Steering is done by looking left and right on the screen.

Evidence for top-down control of eye movements during visual decision making.

PubMed

Glaholt, Mackenzie G; Wu, Mei-Chun; Reingold, Eyal M

2010-05-01

Participants' eye movements were monitored while they viewed displays containing 6 exemplars from one of several categories of everyday items (belts, sunglasses, shirts, shoes), with a column of 3 items presented on the left and another column of 3 items presented on the right side of the display. Participants were either required to choose which of the two sets of 3 items was the most expensive (2-AFC) or which of the 6 items was the most expensive (6-AFC). Importantly, the stimulus display, and the relevant stimulus dimension, were held constant across conditions. Consistent with the hypothesis of top-down control of eye movements during visual decision making, we documented greater selectivity in the processing of stimulus information in the 6-AFC than the 2-AFC decision. In addition, strong spatial biases in looking behavior were demonstrated, but these biases were largely insensitive to the instructional manipulation, and did not substantially influence participants' choices.

The Influence of a Word's Number of Letters, Spatial Extent, and Initial Bigram Characteristics on Eye Movement Control during Reading: Evidence from Arabic

ERIC Educational Resources Information Center

Hermena, Ehab W.; Liversedge, Simon P.; Drieghe, Denis

2017-01-01

The authors conducted 2 eye movement experiments in which they used the typographical and linguistic properties of Arabic to disentangle the influences of words' number of letters and spatial extent on measures of fixation duration and saccade targeting (Experiment 1), and to investigate the influence of initial bigram characteristics on saccade…

Tests of the E-Z Reader Model: Exploring the Interface between Cognition and Eye-Movement Control

ERIC Educational Resources Information Center

Pollatsek, Alexander; Reichle, Erik D.; Rayner, Keith

2006-01-01

This paper is simultaneously a test and refinement of the E-Z Reader model and an exploration of the interrelationship between visual and language processing and eye-movements in reading. Our modeling indicates that the assumption that words in text are processed serially by skilled readers is a viable and attractive hypothesis, as it accounts not…

Reading strategies in mild to moderate strabismic amblyopia: an eye movement investigation.

PubMed

Kanonidou, Evgenia; Proudlock, Frank A; Gottlob, Irene

2010-07-01

PURPOSE. To investigate oculomotor strategies in strabismic amblyopia and evaluate abnormalities during monocular and binocular reading. METHODS. Eye movements were recorded with a head-mounted infrared video eye-tracker (250 Hz, <0.01 degrees resolution) in 20 strabismic amblyopes (mean age, 44.9 +/- 10.7 years) and 20 normal control subjects (mean age, 42.8 +/- 10.9 years) while they silently read paragraphs of text. Monocular reading comparisons were made between the amblyopic eye and the nondominant eye of control subjects and the nonamblyopic eye and the dominant eye of the control subjects. Binocular reading between the amblyopic and control subjects was also compared. RESULTS. Mean reading speed, number of progressive and regressive saccades per line, saccadic amplitude (of progressive saccades), and fixation duration were estimated. Inter- and intrasubject statistical comparisons were made. Reading speed was significantly slower in amblyopes than in control subjects during monocular reading with amblyopic (13.094 characters/s vs. 22.188 characters/s; P < 0.0001) and nonamblyopic eyes (16.241 characters/s vs. 22.349 characters/s, P < 0.0001), and binocularly (15.698 characters/s vs. 23.425 characters/s, P < 0.0001). In amblyopes, reading was significantly slower with the amblyopic eye than with the nonamblyopic eye in binocular viewing (P < 0.05). These differences were associated with significantly more regressive saccades and longer fixation durations, but not with changes in saccadic amplitudes. CONCLUSIONS. In strabismic amblyopia, reading is impaired, not only during monocular viewing with the amblyopic eye, but also with the nonamblyopic eye and binocularly, even though normal visual acuity pertains to the latter two conditions. The impaired reading performance is associated with differences in both the saccadic and fixational patterns, most likely as adaptation strategies to abnormal sensory experiences such as crowding and suppression.

Maximum entropy perception-action space: a Bayesian model of eye movement selection

NASA Astrophysics Data System (ADS)

Colas, Francis; Bessière, Pierre; Girard, Benoît

2011-03-01

In this article, we investigate the issue of the selection of eye movements in a free-eye Multiple Object Tracking task. We propose a Bayesian model of retinotopic maps with a complex logarithmic mapping. This model is structured in two parts: a representation of the visual scene, and a decision model based on the representation. We compare different decision models based on different features of the representation and we show that taking into account uncertainty helps predict the eye movements of subjects recorded in a psychophysics experiment. Finally, based on experimental data, we postulate that the complex logarithmic mapping has a functional relevance, as the density of objects in this space in more uniform than expected. This may indicate that the representation space and control strategies are such that the object density is of maximum entropy.

Countermanding eye-head gaze shifts in humans: marching orders are delivered to the head first.

PubMed

Corneil, Brian D; Elsley, James K

2005-07-01

The countermanding task requires subjects to cancel a planned movement on appearance of a stop signal, providing insights into response generation and suppression. Here, we studied human eye-head gaze shifts in a countermanding task with targets located beyond the horizontal oculomotor range. Consistent with head-restrained saccadic countermanding studies, the proportion of gaze shifts on stop trials increased the longer the stop signal was delayed after target presentation, and gaze shift stop-signal reaction times (SSRTs: a derived statistic measuring how long it takes to cancel a movement) averaged approximately 120 ms across seven subjects. We also observed a marked proportion of trials (13% of all stop trials) during which gaze remained stable but the head moved toward the target. Such head movements were more common at intermediate stop signal delays. We never observed the converse sequence wherein gaze moved while the head remained stable. SSRTs for head movements averaged approximately 190 ms or approximately 70-75 ms longer than gaze SSRTs. Although our findings are inconsistent with a single race to threshold as proposed for controlling saccadic eye movements, movement parameters on stop trials attested to interactions consistent with a race model architecture. To explain our data, we tested two extensions to the saccadic race model. The first assumed that gaze shifts and head movements are controlled by parallel but independent races. The second model assumed that gaze shifts and head movements are controlled by a single race, preceded by terminal ballistic intervals not under inhibitory control, and that the head-movement branch is activated at a lower threshold. Although simulations of both models produced acceptable fits to the empirical data, we favor the second alternative as it is more parsimonious with recent findings in the oculomotor system. Using the second model, estimates for gaze and head ballistic intervals were approximately 25 and 90 ms, respectively, consistent with the known physiology of the final motor paths. Further, the threshold of the head movement branch was estimated to be 85% of that required to activate gaze shifts. From these results, we conclude that a commitment to a head movement is made in advance of gaze shifts and that the comparative SSRT differences result primarily from biomechanical differences inherent to eye and head motion.

Optimal eye movement strategies: a comparison of neurosurgeons gaze patterns when using a surgical microscope.

PubMed

Eivazi, Shahram; Hafez, Ahmad; Fuhl, Wolfgang; Afkari, Hoorieh; Kasneci, Enkelejda; Lehecka, Martin; Bednarik, Roman

2017-06-01

Previous studies have consistently demonstrated gaze behaviour differences related to expertise during various surgical procedures. In micro-neurosurgery, however, there is a lack of evidence of empirically demonstrated individual differences associated with visual attention. It is unknown exactly how neurosurgeons see a stereoscopic magnified view in the context of micro-neurosurgery and what this implies for medical training. We report on an investigation of the eye movement patterns in micro-neurosurgery using a state-of-the-art eye tracker. We studied the eye movements of nine neurosurgeons while performing cutting and suturing tasks under a surgical microscope. Eye-movement characteristics, such as fixation (focus level) and saccade (visual search pattern), were analysed. The results show a strong relationship between the level of microsurgical skill and the gaze pattern, whereas more expertise is associated with greater eye control, stability, and focusing in eye behaviour. For example, in the cutting task, well-trained surgeons increased their fixation durations on the operating field twice as much as the novices (expert, 848 ms; novice, 402 ms). Maintaining steady visual attention on the target (fixation), as well as being able to quickly make eye jumps from one target to another (saccades) are two important elements for the success of neurosurgery. The captured gaze patterns can be used to improve medical education, as part of an assessment system or in a gaze-training application.

[Hypothesis on the equilibrium point and variability of amplitude, speed and time of single-joint movement].

PubMed

Latash, M; Gottleib, G

1990-01-01

Problems of single-joint movement variability are analysed in the framework of the equilibrium-point hypothesis (the lambda-model). Control of the movements is described with three parameters related to movement amplitude speed, and time. Three strategies emerge from this description. Only one of them is likely to lead to a Fitts' type speed-accuracy trade-off. Experiments were performed to test one of the predictions of the model. Subjects performed identical sets of single-joint fast movements with open or closed eyes and some-what different instructions. Movements performed with closed eyes were characterized with higher peak speeds and unchanged variability in seeming violation of the Fitt's law and in a good correspondence to the model.

Tracking the Eye Movement of Four Years Old Children Learning Chinese Words.

PubMed

Lin, Dan; Chen, Guangyao; Liu, Yingyi; Liu, Jiaxin; Pan, Jue; Mo, Lei

2018-02-01

Storybook reading is the major source of literacy exposure for beginning readers. The present study tracked 4-year-old Chinese children's eye movements while they were reading simulated storybook pages. Their eye-movement patterns were examined in relation to their word learning gains. The same reading list, consisting of 20 two-character Chinese words, was used in the pretest, 5-min eye-tracking learning session, and posttest. Additionally, visual spatial skill and phonological awareness were assessed in the pretest as cognitive controls. The results showed that the children's attention was attracted quickly by pictures, on which their attention was focused most, with only 13% of the time looking at words. Moreover, significant learning gains in word reading were observed, from the pretest to posttest, from 5-min exposure to simulated storybook pages with words, picture and pronunciation of two-character words present. Furthermore, the children's attention to words significantly predicted posttest reading beyond socioeconomic status, age, visual spatial skill, phonological awareness and pretest reading performance. This eye-movement evidence of storybook reading by children as young as four years, reading a non-alphabetic script (i.e., Chinese), has demonstrated exciting findings that children can learn words effectively with minimal exposure and little instruction; these findings suggest that learning to read requires attention to the basic words itself. The study contributes to our understanding of early reading acquisition with eye-movement evidence from beginning readers.

Orienting Auditory Spatial Attention Engages Frontal Eye Fields and Medial Occipital Cortex in Congenitally Blind Humans

PubMed Central

Garg, Arun; Schwartz, Daniel; Stevens, Alexander A.

2007-01-01

What happens in vision related cortical areas when congenitally blind (CB) individuals orient attention to spatial locations? Previous neuroimaging of sighted individuals has found overlapping activation in a network of frontoparietal areas including frontal eye-fields (FEF), during both overt (with eye movement) and covert (without eye movement) shifts of spatial attention. Since voluntary eye movement planning seems irrelevant in CB, their FEF neurons should be recruited for alternative functions if their attentional role in sighted individuals is only due to eye movement planning. Recent neuroimaging of the blind has also reported activation in medial occipital areas, normally associated with visual processing, during a diverse set of non-visual tasks, but their response to attentional shifts remains poorly understood. Here, we used event-related fMRI to explore FEF and medial occipital areas in CB individuals and sighted controls with eyes closed (SC) performing a covert attention orienting task, using endogenous verbal cues and spatialized auditory targets. We found robust stimulus-locked FEF activation of all CB subjects, similar but stronger than in SC, suggesting that FEF plays a role in endogenous orienting of covert spatial attention even in individuals in whom voluntary eye movements are irrelevant. We also found robust activation in bilateral medial occipital cortex in CB but not in SC subjects. The response decreased below baseline following endogenous verbal cues but increased following auditory targets, suggesting that the medial occipital area in CB does not directly engage during cued orienting of attention but may be recruited for processing of spatialized auditory targets. PMID:17397882

A novel approach to training attention and gaze in ASD: A feasibility and efficacy pilot study.

PubMed

Chukoskie, Leanne; Westerfield, Marissa; Townsend, Jeanne

2018-05-01

In addition to the social, communicative and behavioral symptoms that define the disorder, individuals with ASD have difficulty re-orienting attention quickly and accurately. Similarly, fast re-orienting saccadic eye movements are also inaccurate and more variable in both endpoint and timing. Atypical gaze and attention are among the earliest symptoms observed in ASD. Disruption of these foundation skills critically affects the development of higher level cognitive and social behavior. We propose that interventions aimed at these early deficits that support social and cognitive skills will be broadly effective. We conducted a pilot clinical trial designed to demonstrate the feasibility and preliminary efficacy of using gaze-contingent video games for low-cost in-home training of attention and eye movement. Eight adolescents with ASD participated in an 8-week training, with pre-, mid- and post-testing of eye movement and attention control. Six of the eight adolescents completed the 8 weeks of training and all six showed improvement in attention (orienting, disengagement) and eye movement control or both. All game systems remained intact for the duration of training and all participants could use the system independently. We delivered a robust, low-cost, gaze-contingent game system for home use that, in our pilot training sample, improved the attention orienting and eye movement performance of adolescent participants in 8 weeks of training. We are currently conducting a clinical trial to replicate these results and to examine what, if any, aspects of training transfer to more real-world tasks. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 546-554, 2018. © 2017 Wiley Periodicals, Inc.

Measuring Human Performance in Simulated Nuclear Power Plant Control Rooms Using Eye Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovesdi, Casey Robert; Rice, Brandon Charles; Bower, Gordon Ross

Control room modernization will be an important part of life extension for the existing light water reactor fleet. As part of modernization efforts, personnel will need to gain a full understanding of how control room technologies affect performance of human operators. Recent advances in technology enables the use of eye tracking technology to continuously measure an operator’s eye movement, which correlates with a variety of human performance constructs such as situation awareness and workload. This report describes eye tracking metrics in the context of how they will be used in nuclear power plant control room simulator studies.

The perception of heading during eye movements

NASA Technical Reports Server (NTRS)

Royden, Constance S.; Banks, Martin S.; Crowell, James A.

1992-01-01

Warren and Hannon (1988, 1990), while studying the perception of heading during eye movements, concluded that people do not require extraretinal information to judge heading with eye/head movements present. Here, heading judgments are examined at higher, more typical eye movement velocities than the extremely slow tracking eye movements used by Warren and Hannon. It is found that people require extraretinal information about eye position to perceive heading accurately under many viewing conditions.

Effects of Reduced Acuity and Stereo Acuity on Saccades and Reaching Movements in Adults With Amblyopia and Strabismus.

PubMed

Niechwiej-Szwedo, Ewa; Goltz, Herbert C; Colpa, Linda; Chandrakumar, Manokaraananthan; Wong, Agnes M F

2017-02-01

Our previous work has shown that amblyopia disrupts the planning and execution of visually-guided saccadic and reaching movements. We investigated the association between the clinical features of amblyopia and aspects of visuomotor behavior that are disrupted by amblyopia. A total of 55 adults with amblyopia (22 anisometropic, 18 strabismic, 15 mixed mechanism), 14 adults with strabismus without amblyopia, and 22 visually-normal control participants completed a visuomotor task while their eye and hand movements were recorded. Univariate and multivariate analyses were performed to assess the association between three clinical predictors of amblyopia (amblyopic eye [AE] acuity, stereo sensitivity, and eye deviation) and seven kinematic outcomes, including saccadic and reach latency, interocular saccadic and reach latency difference, saccadic and reach precision, and PA/We ratio (an index of reach control strategy efficacy using online feedback correction). Amblyopic eye acuity explained 28% of the variance in saccadic latency, and 48% of the variance in mean saccadic latency difference between the amblyopic and fellow eyes (i.e., interocular latency difference). In contrast, for reach latency, AE acuity explained only 10% of the variance. Amblyopic eye acuity was associated with reduced endpoint saccadic (23% of variance) and reach (22% of variance) precision in the amblyopic group. In the strabismus without amblyopia group, stereo sensitivity and eye deviation did not explain any significant variance in saccadic and reach latency or precision. Stereo sensitivity was the best clinical predictor of deficits in reach control strategy, explaining 23% of total variance of PA/We ratio in the amblyopic group and 12% of variance in the strabismus without amblyopia group when viewing with the amblyopic/nondominant eye. Deficits in eye and limb movement initiation (latency) and target localization (precision) were associated with amblyopic acuity deficit, whereas changes in the sensorimotor reach strategy were associated with deficits in stereopsis. Importantly, more than 50% of variance was not explained by the measured clinical features. Our findings suggest that other factors, including higher order visual processing and attention, may have an important role in explaining the kinematic deficits observed in amblyopia.

fMRI evidence for sensorimotor transformations in human cortex during smooth pursuit eye movements.

PubMed

Kimmig, H; Ohlendorf, S; Speck, O; Sprenger, A; Rutschmann, R M; Haller, S; Greenlee, M W

2008-01-01

Smooth pursuit eye movements (SP) are driven by moving objects. The pursuit system processes the visual input signals and transforms this information into an oculomotor output signal. Despite the object's movement on the retina and the eyes' movement in the head, we are able to locate the object in space implying coordinate transformations from retinal to head and space coordinates. To test for the visual and oculomotor components of SP and the possible transformation sites, we investigated three experimental conditions: (I) fixation of a stationary target with a second target moving across the retina (visual), (II) pursuit of the moving target with the second target moving in phase (oculomotor), (III) pursuit of the moving target with the second target remaining stationary (visuo-oculomotor). Precise eye movement data were simultaneously measured with the fMRI data. Visual components of activation during SP were located in the motion-sensitive, temporo-parieto-occipital region MT+ and the right posterior parietal cortex (PPC). Motor components comprised more widespread activation in these regions and additional activations in the frontal and supplementary eye fields (FEF, SEF), the cingulate gyrus and precuneus. The combined visuo-oculomotor stimulus revealed additional activation in the putamen. Possible transformation sites were found in MT+ and PPC. The MT+ activation evoked by the motion of a single visual dot was very localized, while the activation of the same single dot motion driving the eye was rather extended across MT+. The eye movement information appeared to be dispersed across the visual map of MT+. This could be interpreted as a transfer of the one-dimensional eye movement information into the two-dimensional visual map. Potentially, the dispersed information could be used to remap MT+ to space coordinates rather than retinal coordinates and to provide the basis for a motor output control. A similar interpretation holds for our results in the PPC region.

Using eye movements as an index of implicit face recognition in autism spectrum disorder.

PubMed

Hedley, Darren; Young, Robyn; Brewer, Neil

2012-10-01

Individuals with an autism spectrum disorder (ASD) typically show impairment on face recognition tasks. Performance has usually been assessed using overt, explicit recognition tasks. Here, a complementary method involving eye tracking was used to examine implicit face recognition in participants with ASD and in an intelligence quotient-matched non-ASD control group. Differences in eye movement indices between target and foil faces were used as an indicator of implicit face recognition. Explicit face recognition was assessed using old-new discrimination and reaction time measures. Stimuli were faces of studied (target) or unfamiliar (foil) persons. Target images at test were either identical to the images presented at study or altered by changing the lighting, pose, or by masking with visual noise. Participants with ASD performed worse than controls on the explicit recognition task. Eye movement-based measures, however, indicated that implicit recognition may not be affected to the same degree as explicit recognition. Autism Res 2012, 5: 363-379. © 2012 International Society for Autism Research, Wiley Periodicals, Inc. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

Eye Movements during Silent and Oral Reading in a Regular Orthography: Basic Characteristics and Correlations with Childhood Cognitive Abilities and Adolescent Reading Skills

PubMed Central

Krieber, Magdalena; Bartl-Pokorny, Katrin D.; Pokorny, Florian B.; Zhang, Dajie; Landerl, Karin; Körner, Christof; Pernkopf, Franz; Pock, Thomas; Einspieler, Christa; Marschik, Peter B.

2017-01-01

The present study aimed to define differences between silent and oral reading with respect to spatial and temporal eye movement parameters. Eye movements of 22 German-speaking adolescents (14 females; mean age = 13;6 years;months) were recorded while reading an age-appropriate text silently and orally. Preschool cognitive abilities were assessed at the participants’ age of 5;7 (years;months) using the Kaufman Assessment Battery for Children. The participants’ reading speed and reading comprehension at the age of 13;6 (years;months) were determined using a standardized inventory to evaluate silent reading skills in German readers (Lesegeschwindigkeits- und -verständnistest für Klassen 6–12). The results show that (i) reading mode significantly influenced both spatial and temporal characteristics of eye movement patterns; (ii) articulation decreased the consistency of intraindividual reading performances with regard to a significant number of eye movement parameters; (iii) reading skills predicted the majority of eye movement parameters during silent reading, but influenced only a restricted number of eye movement parameters when reading orally; (iv) differences with respect to a subset of eye movement parameters increased with reading skills; (v) an overall preschool cognitive performance score predicted reading skills at the age of 13;6 (years;months), but not eye movement patterns during either silent or oral reading. However, we found a few significant correlations between preschool performances on subscales of sequential and simultaneous processing and eye movement parameters for both reading modes. Overall, the findings suggest that eye movement patterns depend on the reading mode. Preschool cognitive abilities were more closely related to eye movement patterns of oral than silent reading, while reading skills predicted eye movement patterns during silent reading, but less so during oral reading. PMID:28151950

A case of double depressor palsy followed by pursuit deficit due to sequential infarction in bilateral thalamus and right medial superior temporal area.

PubMed

Kim, Su Jin; Yeom, Myeong In; Lee, Seung Uk

2017-12-01

We present a unique case of a patient who suffered two rare events affecting the supranuclear control, first of the vertical and second of the horizontal eye movements. The first event involved bilateral thalamic infarcts that resulted in double depressor palsy. The second event occurred 1 year later and it involved supranuclear control of horizontal eye movements creating pursuit deficit. A 47-year-old male presented with complaints of diplopia upon awakening. He had atrial fibrillation, mitral valve regurgitation, aortic valve regurgitation, and a history of spleen infarction 1 year ago. His right eye was hypertrophic and right eye downgaze was limited unilaterally of equal degree in adduction and abduction. The patient was diagnosed with double depressor palsy of the right eye. Magnetic resonance imaging (MRI) of the brain showed an old infarction of the left thalamus, and diffusion MRI showed acute infarction of the right thalamus. The patient's daily warfarin dose was 2 mg and it was increased to 5 mg with cilostazol 75 mg twice a day. Seven weeks later, the patient's ocular movement revealed near normal muscle action, and subjectively, the patient was diplopia free. At follow-up 12 months later, the patient revisited the hospital because of sudden onset of blurred vision on right gaze. He was observed to have smooth pursuit deficit to the right side, and orthophoric position of the eyes in primary gaze. MRI of the brain showed an acute infarction in the right medial superior temporal area. The patient experienced very rare abnormal eyeball movements twice. This case highlights the importance of evaluating vertical movement of the eyes and vascular supplies when patients present with depressor deficit and supports the theory of a supranuclear function in patients who present with pursuit deficit.

Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study.

PubMed

Ivanov, Iliya V; Mackeben, Manfred; Vollmer, Annika; Martus, Peter; Nguyen, Nhung X; Trauzettel-Klosinski, Susanne

2016-01-01

Degenerative retinal diseases, especially retinitis pigmentosa (RP), lead to severe peripheral visual field loss (tunnel vision), which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST). Oculomotor responses during walking and avoiding obstacles in a controlled environment were studied before and after saccade or reading training in 25 RP patients. Eye movements were recorded using a mobile infrared eye tracker (Tobii glasses) that measured a range of spatial and temporal variables. Patients were randomly assigned to two training conditions: Saccade (experimental) and reading (control) training. All subjects who first performed reading training underwent experimental training later (waiting list control group). To assess the effect of training on subjects, we measured performance in the training task and the following outcome variables related to daily life: Response Time (RT) during exploratory saccade training, Percent Preferred Walking Speed (PPWS), the number of collisions with obstacles, eye position variability, fixation duration, and the total number of fixations including the ones in the subjects' blind area of the visual field. In the saccade training group, RTs on average decreased, while the PPWS significantly increased. The improvement persisted, as tested 6 weeks after the end of the training. On average, the eye movement range of RP patients before and after training was similar to that of healthy observers. In both, the experimental and reading training groups, we found many fixations outside the subjects' seeing visual field before and after training. The average fixation duration was significantly shorter after the training, but only in the experimental training condition. We conclude that the exploratory saccade training was beneficial for RP patients and resulted in shorter fixation durations after the training. We also found a significant improvement in relative walking speed during navigation in a real-world like controlled environment.

Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study

PubMed Central

Ivanov, Iliya V.; Mackeben, Manfred; Vollmer, Annika; Martus, Peter; Nguyen, Nhung X.; Trauzettel-Klosinski, Susanne

2016-01-01

Purpose Degenerative retinal diseases, especially retinitis pigmentosa (RP), lead to severe peripheral visual field loss (tunnel vision), which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST). Methods Oculomotor responses during walking and avoiding obstacles in a controlled environment were studied before and after saccade or reading training in 25 RP patients. Eye movements were recorded using a mobile infrared eye tracker (Tobii glasses) that measured a range of spatial and temporal variables. Patients were randomly assigned to two training conditions: Saccade (experimental) and reading (control) training. All subjects who first performed reading training underwent experimental training later (waiting list control group). To assess the effect of training on subjects, we measured performance in the training task and the following outcome variables related to daily life: Response Time (RT) during exploratory saccade training, Percent Preferred Walking Speed (PPWS), the number of collisions with obstacles, eye position variability, fixation duration, and the total number of fixations including the ones in the subjects' blind area of the visual field. Results In the saccade training group, RTs on average decreased, while the PPWS significantly increased. The improvement persisted, as tested 6 weeks after the end of the training. On average, the eye movement range of RP patients before and after training was similar to that of healthy observers. In both, the experimental and reading training groups, we found many fixations outside the subjects' seeing visual field before and after training. The average fixation duration was significantly shorter after the training, but only in the experimental training condition. Conclusions We conclude that the exploratory saccade training was beneficial for RP patients and resulted in shorter fixation durations after the training. We also found a significant improvement in relative walking speed during navigation in a real-world like controlled environment. PMID:27351629

Decline of vertical gaze and convergence with aging.

PubMed

Oguro, Hiroaki; Okada, Kazunori; Suyama, Nobuo; Yamashita, Kazuya; Yamaguchi, Shuhei; Kobayashi, Shotai

2004-01-01

Disturbance of vertical eye movement and ocular convergence is often observed in elderly people, but little is known about its frequency. The purpose of this study was to investigate age-associated changes in vertical eye movement and convergence in healthy elderly people, using a digital video camera system. We analyzed vertical eye movements and convergence in 113 neurologically normal elderly subjects (mean age 70 years) in comparison with 20 healthy young controls (mean age 32 years). The range of vertical eye movement was analyzed quantitatively and convergence was analyzed qualitatively. In the elderly subjects, the angle of vertical gaze decreased with advancing age and it was significantly smaller than that of the younger subjects. The mean angle of upward gaze was significantly smaller than that of downward gaze for both young and elderly subjects. Upward gaze impairment became apparent in subjects in their 70s, and downward gaze impairment in subjects in their 60s. Disturbance in convergence also increased with advancing age, and was found in 40.7% of the elderly subjects. These findings indicate that the mechanisms of age-related change are different for upward and downward vertical gaze. Digital video camera monitoring was useful for assessing and monitoring eye movements. Copyright 2004 S. Karger AG, Basel

Eye Movement Disorders

MedlinePlus

... t work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... of the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over ...

Research and Studies Directory for Manpower, Personnel, and Training

DTIC Science & Technology

1989-05-01

LOUIS MO 314-889-6805 CONTROL OF BIOSONAR BEHAVIOR BY THE AUDITORY CORTEX TANGNEY J AIR FORCE OFFICE OF SCIENTIFIC RESEARCH 202-767-5021 A MODEL FOR...VISUAL ATTENTION AUDITORY PERCEPTION OF COMPLEX SOUNDS CONTROL OF BIOSONAR BEHAVIOR BY THE AUDITORY CORTEX EYE MOVEMENTS AND SPATIAL PATTERN VISION EYE

Pioneers of eye movement research

PubMed Central

Wade, Nicholas J

2010-01-01

Recent advances in the technology affording eye movement recordings carry the risk of neglecting past achievements. Without the assistance of this modern armoury, great strides were made in describing the ways the eyes move. For Aristotle the fundamental features of eye movements were binocular, and he described the combined functions of the eyes. This was later given support using simple procedures like placing a finger over the eyelid of the closed eye and culminated in Hering's law of equal innervation. However, the overriding concern in the 19th century was with eye position rather than eye movements. Appreciating discontinuities of eye movements arose from studies of vertigo. The characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare in 1879; both used similar techniques of listening to sounds made during contractions of the extraocular muscles. Photographic records of eye movements during reading were made by Dodge early in the 20th century, and this stimulated research using a wider array of patterns. In the mid-20th century attention shifted to the stability of the eyes during fixation, with the emphasis on involuntary movements. The contributions of pioneers from Aristotle to Yarbus are outlined. PMID:23396982

Reading in Schizophrenic Subjects and Their Nonsymptomatic First-Degree Relatives

PubMed Central

Roberts, Eryl O.; Proudlock, Frank A.; Martin, Kate; Reveley, Michael A.; Al-Uzri, Mohammed; Gottlob, Irene

2013-01-01

Previous studies have demonstrated eye movement abnormalities during smooth pursuit and antisaccadic tasks in schizophrenia. However, eye movements have not been investigated during reading. The purpose of this study was to determine whether schizophrenic subjects and their nonsymptomatic first-degree relatives show eye movement abnormalities during reading. Reading rate, number of saccades per line, amplitudes of saccades, percentage regressions (reverse saccades), and fixation durations were measured using an eye tracker (EyeLink, SensoMotoric Instruments, Germany) in 38 schizophrenic volunteers, 14 nonaffected first-degree relatives, and 57 control volunteers matched for age and National Adult Reading Test scores. Parameters were examined when volunteers read full pages of text and text was limited to progressively smaller viewing areas around the point of fixation using a gaze-contingent window. Schizophrenic volunteers showed significantly slower reading rates (P = .004), increase in total number of saccades (P ≤ .001), and a decrease in saccadic amplitude (P = .025) while reading. Relatives showed a significant increase in total number of saccades (P = .013) and decrease in saccadic amplitude (P = .020). Limitation of parafoveal information by reducing the amount of visible characters did not change the reading rate of schizophrenics but controls showed a significant decrease in reading rate with reduced parafoveal information (P < .001). Eye movement abnormalities during reading of schizophrenic volunteers and their first-degree relatives suggest that visual integration of foveal and parafoveal information may be reduced in schizophrenia. Reading abnormalities in relatives suggest a genetic influence in reading ability in schizophrenia and rule out confounding effects of medication. PMID:22267532

Lexical and Post-Lexical Complexity Effects on Eye Movements in Reading

PubMed Central

Warren, Tessa; Reichle, Erik D.; Patson, Nikole D.

2011-01-01

The current study investigated how a post-lexical complexity manipulation followed by a lexical complexity manipulation affects eye movements during reading. Both manipulations caused disruption in all measures on the manipulated words, but the patterns of spill-over differed. Critically, the effects of the two kinds of manipulations did not interact, and there was no evidence that post-lexical processing difficulty delayed lexical processing on the next word (c.f. Henderson & Ferreira, 1990). This suggests that post-lexical processing of one word and lexical processing of the next can proceed independently and likely in parallel. This finding is consistent with the assumptions of the E-Z Reader model of eye movement control in reading (Reichle, Warren, & McConnell, 2009). PMID:21603125

Voluntary presetting of the vestibular ocular reflex permits gaze stabilization despite perturbation of fast head movements

NASA Technical Reports Server (NTRS)

Zangemeister, Wolfgang H.

1989-01-01

Normal subjects are able to change voluntarily and continuously their head-eye latency together with their compensatory eye movement gain. A continuous spectrum of intent-latency modes of the subject's coordinated gaze through verbal feedback could be demonstrated. It was also demonstrated that the intent to counteract any perturbation of head-eye movement, i.e., the mental set, permitted the subjects to manipulate consciously their vestibular ocular reflex (VOR) gain. From the data, it is inferred that the VOR is always on. It may be, however, variably suppressed by higher cortical control. With appropriate training, head-mounted displays should permit an easy VOR presetting that leads to image stabilization, perhaps together with a decrease of possible misjudgements.

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2

PubMed Central

Schrölkamp, Maren; Jennum, Poul J.; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R.; Knudsen, Stine

2017-01-01

Study Objectives: Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Methods: Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. Results: CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Conclusions: Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy. Citation: Schrölkamp M, Jennum PJ, Gammeltoft S, Holm A, Kornum BR, Knudsen S. Normal morning melanin-concentrating hormone levels and no association with rapid eye movement or non-rapid eye movement sleep parameters in narcolepsy type 1 and type 2. J Clin Sleep Med. 2017;13(2):235–243. PMID:27855741

Eye movement perimetry in glaucoma.

PubMed

Trope, G E; Eizenman, M; Coyle, E

1989-08-01

Present-day computerized perimetry is often inaccurate and unreliable owing to the need to maintain central fixation over long periods while repressing the normal response to presentation of peripheral stimuli. We tested a new method of perimetry that does not require prolonged central fixation. During this test eye movements were encouraged on presentation of a peripheral target. Twenty-three eyes were studied with an Octopus perimeter, with a technician monitoring eye movements. The sensitivity was 100% and the specificity 23%. The low specificity was due to the technician's inability to accurately monitor small eye movements in the central 6 degrees field. If small eye movements are monitored accurately with an eye tracker, eye movement perimetry could become an alternative method to standard perimetry.

The zoom lens of attention: Simulating shuffled versus normal text reading using the SWIFT model

PubMed Central

Schad, Daniel J.; Engbert, Ralf

2012-01-01

Assumptions on the allocation of attention during reading are crucial for theoretical models of eye guidance. The zoom lens model of attention postulates that attentional deployment can vary from a sharp focus to a broad window. The model is closely related to the foveal load hypothesis, i.e., the assumption that the perceptual span is modulated by the difficulty of the fixated word. However, these important theoretical concepts for cognitive research have not been tested quantitatively in eye movement models. Here we show that the zoom lens model, implemented in the SWIFT model of saccade generation, captures many important patterns of eye movements. We compared the model's performance to experimental data from normal and shuffled text reading. Our results demonstrate that the zoom lens of attention might be an important concept for eye movement control in reading. PMID:22754295

How detrimental is eye movement during photorefractive keratectomy to the patient's postoperative vision?

NASA Astrophysics Data System (ADS)

Taylor, Natalie M.; van Saarloos, Paul P.; Eikelboom, Robert H.

2000-06-01

This study aimed to gauge the effect of the patient's eye movement during Photo Refractive Keratectomy (PRK) on post- operative vision. A computer simulation of both the PRK procedure and the visual outcome has been performed. The PRK simulation incorporated the pattern of movement of the laser beam to perform a given correction, the beam characteristics, an initial corneal profile, and an eye movement scenario; and generated the corrected corneal profile. The regrowth of the epithelium was simulated by selecting the smoothing filter which, when applied to a corrected cornea with no patient eye movement, produced similar ray tracing results to the original corneal model. Ray tracing several objects, such as letters of various contrast and sizes was performed to assess the quality of the post-operative vision. Eye movement scenarios included no eye movement, constant decentration and normally distributed random eye movement of varying magnitudes. Random eye movement of even small amounts, such as 50 microns reduces the contrast sensitivity of the image. Constant decentration decenters the projected image on the retina, and in extreme cases can lead to astigmatism. Eye movements of the magnitude expected during laser refractive surgery have minimal effect on the final visual outcome.

Eye Movement in Unipolar and Bipolar Depression: A Systematic Review of the Literature

PubMed Central

Carvalho, Nicolas; Laurent, Eric; Noiret, Nicolas; Chopard, Gilles; Haffen, Emmanuel; Bennabi, Djamila; Vandel, Pierre

2015-01-01

Background: The analysis of eye movements (EM) by eye-tracking has been carried out for several decades to investigate mood regulation, emotional information processing, and psychomotor disturbances in depressive disorders. Method: A systematic review of all English language PubMed articles using the terms “saccadic eye movements” OR “eye-tracking” AND “depression” OR “bipolar disorders” was conducted using PRISMA guidelines. The aim of this review was to characterize the specific alterations of EM in unipolar and bipolar depression. Results: Findings regarding psychomotor disturbance showed an increase in reaction time in prosaccade and antisaccade tasks in both unipolar and bipolar disorders. In both disorders, patients have been reported to have an attraction for negative emotions, especially for negative pictures in unipolar and threatening images in bipolar disorder. However, the pattern could change with aging, elderly unipolar patients disengaging key features of sad and neutral stimuli. Methodological limitations generally include small sample sizes with mixed unipolar and bipolar depressed patients. Conclusion: Eye movement analysis can be used to discriminate patients with depressive disorders from controls, as well as patients with bipolar disorder from patients with unipolar depression. General knowledge concerning psychomotor alterations and affective regulation strategies associated with each disorder can also be gained thanks to the analysis. Future directions for research on eye movement and depression are proposed in this review. PMID:26696915

Hierarchical control of two-dimensional gaze saccades

PubMed Central

Optican, Lance M.; Blohm, Gunnar; Lefèvre, Philippe

2014-01-01

Coordinating the movements of different body parts is a challenging process for the central nervous system because of several problems. Four of these main difficulties are: first, moving one part can move others; second, the parts can have different dynamics; third, some parts can have different motor goals; and fourth, some parts may be perturbed by outside forces. Here, we propose a novel approach for the control of linked systems with feedback loops for each part. The proximal parts have separate goals, but critically the most distal part has only the common goal. We apply this new control policy to eye-head coordination in two-dimensions, specifically head-unrestrained gaze saccades. Paradoxically, the hierarchical structure has controllers for the gaze and the head, but not for the eye (the most distal part). Our simulations demonstrate that the proposed control structure reproduces much of the published empirical data about gaze movements, e.g., it compensates for perturbations, accurately reaches goals for gaze and head from arbitrary initial positions, simulates the nine relationships of the head-unrestrained main sequence, and reproduces observations from lesion and single-unit recording experiments. We conclude by showing how our model can be easily extended to control structures with more linked segments, such as the control of coordinated eye on head on trunk movements. PMID:24062206

Role of the human supplementary eye field in the control of saccadic eye movements

PubMed Central

Parton, Andrew; Nachev, Parashkev; Hodgson, Timothy L.; Mort, Dominic; Thomas, David; Ordidge, Roger; Morgan, Paul S.; Jackson, Stephen; Rees, Geraint; Husain, Masud

2007-01-01

The precise function of the supplementary eye field (SEF) is poorly understood. Although electrophysiological and functional imaging studies are important for demonstrating when SEF neurones are active, lesion studies are critical to establish the functions for which the SEF is essential. Here we report a series of investigations performed on an extremely rare individual with a highly focal lesion of the medial frontal cortex. High-resolution structural imaging demonstrated that his lesion was confined to the region of the left paracentral sulcus, the anatomical locus of the SEF. Behavioural testing revealed that the patient was significantly impaired when required to switch between anti- and pro-saccades, when there were conflicting rules governing stimulus–response mappings for saccades. Similarly, the results of an arbitrary stimulus–response associative learning task demonstrated that he was impaired when required to select the appropriate saccade from conflicting eye movement responses, but not for limb movements on an analogous manual task. When making memory-guided saccadic sequences, the patient demonstrated hypometria, like patients with Parkinson's disease, but had no significant difficulties in reproducing the order of saccades correctly on a task that emphasized accuracy with a wide temporal segregation between responses. These findings are consistent with the hypothesis that the SEF plays a key role in implementing control when there is conflict between several, ongoing competing saccadic responses, but not when eye movements need to be made accurately in sequence. PMID:17069864

Eye movement-invariant representations in the human visual system.

PubMed

Nishimoto, Shinji; Huth, Alexander G; Bilenko, Natalia Y; Gallant, Jack L

2017-01-01

During natural vision, humans make frequent eye movements but perceive a stable visual world. It is therefore likely that the human visual system contains representations of the visual world that are invariant to eye movements. Here we present an experiment designed to identify visual areas that might contain eye-movement-invariant representations. We used functional MRI to record brain activity from four human subjects who watched natural movies. In one condition subjects were required to fixate steadily, and in the other they were allowed to freely make voluntary eye movements. The movies used in each condition were identical. We reasoned that the brain activity recorded in a visual area that is invariant to eye movement should be similar under fixation and free viewing conditions. In contrast, activity in a visual area that is sensitive to eye movement should differ between fixation and free viewing. We therefore measured the similarity of brain activity across repeated presentations of the same movie within the fixation condition, and separately between the fixation and free viewing conditions. The ratio of these measures was used to determine which brain areas are most likely to contain eye movement-invariant representations. We found that voxels located in early visual areas are strongly affected by eye movements, while voxels in ventral temporal areas are only weakly affected by eye movements. These results suggest that the ventral temporal visual areas contain a stable representation of the visual world that is invariant to eye movements made during natural vision.

Learning optimal eye movements to unusual faces

PubMed Central

Peterson, Matthew F.; Eckstein, Miguel P.

2014-01-01

Eye movements, which guide the fovea’s high resolution and computational power to relevant areas of the visual scene, are integral to efficient, successful completion of many visual tasks. How humans modify their eye movements through experience with their perceptual environments, and its functional role in learning new tasks, has not been fully investigated. Here, we used a face identification task where only the mouth discriminated exemplars to assess if, how, and when eye movement modulation may mediate learning. By interleaving trials of unconstrained eye movements with trials of forced fixation, we attempted to separate the contributions of eye movements and covert mechanisms to performance improvements. Without instruction, a majority of observers substantially increased accuracy and learned to direct their initial eye movements towards the optimal fixation point. The proximity of an observer’s default face identification eye movement behavior to the new optimal fixation point and the observer’s peripheral processing ability were predictive of performance gains and eye movement learning. After practice in a subsequent condition in which observers were directed to fixate different locations along the face, including the relevant mouth region, all observers learned to make eye movements to the optimal fixation point. In this fully learned state, augmented fixation strategy accounted for 43% of total efficiency improvements while covert mechanisms accounted for the remaining 57%. The findings suggest a critical role for eye movement planning to perceptual learning, and elucidate factors that can predict when and how well an observer can learn a new task with unusual exemplars. PMID:24291712

Validation of mobile eye-tracking as novel and efficient means for differentiating progressive supranuclear palsy from Parkinson's disease

PubMed Central

Marx, Svenja; Respondek, Gesine; Stamelou, Maria; Dowiasch, Stefan; Stoll, Josef; Bremmer, Frank; Oertel, Wolfgang H.; Höglinger, Günter U.; Einhäuser, Wolfgang

2012-01-01

Background: The decreased ability to carry out vertical saccades is a key symptom of Progressive Supranuclear Palsy (PSP). Objective measurement devices can help to reliably detect subtle eye movement disturbances to improve sensitivity and specificity of the clinical diagnosis. The present study aims at transferring findings from restricted stationary video-oculography (VOG) to a wearable head-mounted device, which can be readily applied in clinical practice. Methods: We investigated the eye movements in 10 possible or probable PSP patients, 11 Parkinson's disease (PD) patients, and 10 age-matched healthy controls (HCs) using a mobile, gaze-driven video camera setup (EyeSeeCam). Ocular movements were analyzed during a standardized fixation protocol and in an unrestricted real-life scenario while walking along a corridor. Results: The EyeSeeCam detected prominent impairment of both saccade velocity and amplitude in PSP patients, differentiating them from PD and HCs. Differences were particularly evident for saccades in the vertical plane, and stronger for saccades than for other eye movements. Differences were more pronounced during the standardized protocol than in the real-life scenario. Conclusions: Combined analysis of saccade velocity and saccade amplitude during the fixation protocol with the EyeSeeCam provides a simple, rapid (<20 s), and reliable tool to differentiate clinically established PSP patients from PD and HCs. As such, our findings prepare the ground for using wearable eye-tracking in patients with uncertain diagnoses. PMID:23248593

Reading strategies in infantile nystagmus syndrome.

PubMed

Thomas, Mervyn G; Gottlob, Irene; McLean, Rebecca J; Maconachie, Gail; Kumar, Anil; Proudlock, Frank A

2011-10-17

The adaptive strategies adopted by individuals with infantile nystagmus syndrome (INS) during reading are not clearly understood. Eye movement recordings were used to identify ocular motor strategies used by patients with INS during reading. Eye movements were recorded at 500 Hz in 25 volunteers with INS and 7 controls when reading paragraphs of text centered at horizontal gaze angles of -20°, -10°, 0°, 10°, and 20°. At each location, reading speeds were measured, along with logMAR visual acuity and nystagmus during gaze-holding. Adaptive strategies were identified from slow and quick-phase patterns in the nystagmus waveform. Median reading speeds were 204.3 words per minute in individuals with INS and 273.6 words per minute in controls. Adaptive strategies included (1) suppression of corrective quick phases allowing involuntary slow phases to achieve the desired goal, (2) voluntarily changing the character of the involuntary slow phases using quick phases, and (3) correction of involuntary slow phases using quick phases. Several individuals with INS read more rapidly than healthy control volunteers. These findings demonstrate that volunteers with INS learn to manipulate their nystagmus using a range of strategies to acquire visual information from the text. These strategies include taking advantage of the stereotypical and periodic nature of involuntary eye movements to allow the involuntary eye movements to achieve the desired goal. The versatility of these adaptations yields reading speeds in those with nystagmus that are often much better than might be expected, given the degree of foveal and ocular motor deficits.

Active ocular vergence improves postural control in elderly as close viewing distance with or without a single cognitive task.

PubMed

Matheron, Eric; Yang, Qing; Delpit-Baraut, Vincent; Dailly, Olivier; Kapoula, Zoï

2016-01-01

Performance of the vestibular, visual, and somatosensory systems decreases with age, reducing the capacity of postural control, and increasing the risk of falling. The purpose of this study is to measure the effects of vision, active vergence eye movements, viewing distance/vergence angle and a simple cognitive task on postural control during an upright stance, in completely autonomous elderly individuals. Participated in the study, 23 elderly subjects (73.4 ± 6.8 years) who were enrolled in a center dedicated to the prevention of falling. Their body oscillations were measured with the DynaPort(®) device, with three accelerometers, placed at the lumbosacral level, near the center of mass. The conditions were the following: eyes open fixating on LED at 20 cm or 150 cm (vergence angle 17.0° and 2.3° respectively) with or without additional cognitive tasks (counting down from one hundred), performing active vergence by alternating the fixation between the far and the near LED (convergence and divergence), eyes closed after having fixated the far LED. The results showed that the postural stability significantly decreased when fixating on the LED at a far distance (weak convergence angle) with or without cognitive tasks; active convergence-divergence between the LEDs improved the postural stability while eye closure decreased it. The privilege of proximity (with increased convergence at near), previously established with foot posturography, is shown here to be valid for accelerometry with the center of mass in elderly. Another major result is the beneficial contribution of active vergence eye movements to better postural stability. The results bring new perspectives for the role of eye movement training to preserve postural control and autonomy in elderly. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The effect of face exploration on postural control in healthy children.

PubMed

Goulème, Nathalie; Seassau, Magali; Bucci, Maria Pia

2015-07-01

The objective was to explore how face exploration affects postural control in healthy children. The novelty here is that eye movements and posture were simultaneously recorded. Three groups of children participated in the study: 12 children of 7.8±0.5 years old, 13 children of 10.4±0.5 years old and 12 children of 15.7±0.9 years old. Eye movements were recorded by video-oculography and postural stability was recorded by a platform. Children were invited to explore five emotional faces (neutral, happy, sad fear and angry). Analysis of eye movements was done on saccadic latency, percentage of exploration time spent and number of saccades for each specific region of interest (ROI): eyes, nose and mouth. Analysis of posture was made on surface area, sway length and mean velocity of the center of pressures (CoP). Results showed that visual strategies, exploration and postural control develop during childhood and adolescence. Indeed, after nine years-old, children started to look the eyes ROI firstly, then the nose ROI and finally the mouth ROI. The number of saccades decreased with the age of children. The percentage of exploration time spent in eyes ROI was longer than the others ROIs and greater for unpleasant faces (sad, fear and angry) with respect to pleasant emotional face (happy). We found that in front of sad and happy faces the surface area of the CoP was significantly larger compared to other faces (neutral and angry). These results suggest that visual strategies and postural control change during children's development and can be influenced by the emotional face. Copyright © 2015 Elsevier B.V. All rights reserved.

Fetal eye movements on magnetic resonance imaging.

PubMed

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Dynamic SSFP sequences were acquired in 72 singleton fetuses (17-40 GW, three age groups [17-23 GW, 24-32 GW, 33-40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3-45%. In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations.

Compensating For Movement Of Eye In Laser Surgery

NASA Technical Reports Server (NTRS)

Juday, Richard D.

1991-01-01

Conceptual system for laser surgery of retina includes subsystem that tracks position of retina. Tracking signal used to control galvanometer-driven mirrors keeping laser aimed at desired spot on retina as eye moves. Alternatively or additionally, indication of position used to prevent firing of laser when eye moved too far from proper aiming position.

Eye gaze tracking for endoscopic camera positioning: an application of a hardware/software interface developed to automate Aesop.

PubMed

Ali, S M; Reisner, L A; King, B; Cao, A; Auner, G; Klein, M; Pandya, A K

2008-01-01

A redesigned motion control system for the medical robot Aesop allows automating and programming its movements. An IR eye tracking system has been integrated with this control interface to implement an intelligent, autonomous eye gaze-based laparoscopic positioning system. A laparoscopic camera held by Aesop can be moved based on the data from the eye tracking interface to keep the user's gaze point region at the center of a video feedback monitor. This system setup provides autonomous camera control that works around the surgeon, providing an optimal robotic camera platform.

Diagnosis of mild Alzheimer disease through the analysis of eye movements during reading.

PubMed

Fernández, Gerardo; Castro, Liliana R; Schumacher, Marcela; Agamennoni, Osvaldo E

2015-03-01

Reading requires the integration of several central cognitive subsystems, ranging from attention and oculomotor control to word identification and language comprehension. Reading saccades and fixations contain information that can be correlated with word properties. When reading a sentence, the brain must decide where to direct the next saccade according to what has been read up to the actual fixation. In this process, the retrieval memory brings information about the current word features and attributes into working memory. According to this information, the prefrontal cortex predicts and triggers the next saccade. The frequency and cloze predictability of the fixated word, the preceding words and the upcoming ones affect when and where the eyes will move next. In this paper we present a diagnostic technique for early stage cognitive impairment detection by analyzing eye movements during reading proverbs. We performed a case-control study involving 20 patients with probable Alzheimer's disease and 40 age-matched, healthy control patients. The measurements were analyzed using linear mixed-effects models, revealing that eye movement behavior while reading can provide valuable information about whether a person is cognitively impaired. To the best of our knowledge, this is the first study using word-based properties, proverbs and linear mixed-effect models for identifying cognitive abnormalities.

ECEM (Eye Closure, Eye Movements): application to depersonalization disorder.

PubMed

Harriet, E Hollander

2009-10-01

Eye Closure, Eye Movements (ECEM) is a hypnotically-based approach to treatment that incorporates eye movements adapted from the Eye Movement Desensitization and Reprocessing (EMDR) protocol in conjunction with hypnosis for the treatment of depersonalization disorder. Depersonalization Disorder has been differentiated from post-traumatic stress disorders and has recently been conceptualized as a subtype of panic disorder (Baker et al., 2003; David, Phillips, Medford, & Sierra, 2004; Segui et. al., 2000). During ECEM, while remaining in a hypnotic state, clients self-generated six to seven trials of eye movements to reduce anticipatory anxiety associated with depersonalization disorder. Eye movements were also used to process triggers that elicited breath holding, often followed by episodes of depersonalization. Hypnotic suggestions were used to reverse core symptoms of depersonalization, subjectively described as "feeling unreal" (Simeon et al., 1997).

Goal-Directed and Goal-Less Imitation in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Wild, Kelly S.; Poliakoff, Ellen; Jerrison, Andrew; Gowen, Emma

2012-01-01

To investigate how people with Autism are affected by the presence of goals during imitation, we conducted a study to measure movement kinematics and eye movements during the imitation of goal-directed and goal-less hand movements. Our results showed that a control group imitated changes in movement kinematics and increased the level that they…

Contribution of the frontal eye field to gaze shifts in the head-unrestrained rhesus monkey: neuronal activity.

PubMed

Knight, T A

2012-12-06

The frontal eye field (FEF) has a strong influence on saccadic eye movements with the head restrained. With the head unrestrained, eye saccades combine with head movements to produce large gaze shifts, and microstimulation of the FEF evokes both eye and head movements. To test whether the dorsomedial FEF provides commands for the entire gaze shift or its separate eye and head components, we recorded extracellular single-unit activity in monkeys trained to make large head-unrestrained gaze shifts. We recorded 80 units active during gaze shifts, and closely examined 26 of these that discharged a burst of action potentials that preceded horizontal gaze movements. These units were movement or visuomovement related and most exhibited open movement fields with respect to amplitude. To reveal the relations of burst parameters to gaze, eye, and/or head movement metrics, we used behavioral dissociations of gaze, eye, and head movements and linear regression analyses. The burst number of spikes (NOS) was strongly correlated with movement amplitude and burst temporal parameters were strongly correlated with movement temporal metrics for eight gaze-related burst neurons and five saccade-related burst neurons. For the remaining 13 neurons, the NOS was strongly correlated with the head movement amplitude, but burst temporal parameters were most strongly correlated with eye movement temporal metrics (head-eye-related burst neurons, HEBNs). These results suggest that FEF units do not encode a command for the unified gaze shift only; instead, different units may carry signals related to the overall gaze shift or its eye and/or head components. Moreover, the HEBNs exhibit bursts whose magnitude and timing may encode a head displacement signal and a signal that influences the timing of the eye saccade, thereby serving as a mechanism for coordinating the eye and head movements of a gaze shift. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of bilateral eye movements on the retrieval of item, associative, and contextual information.

PubMed

Parker, Andrew; Relph, Sarah; Dagnall, Neil

2008-01-01

Two experiments are reported that investigate the effects of saccadic bilateral eye movements on the retrieval of item, associative, and contextual information. Experiment 1 compared the effects of bilateral versus vertical versus no eye movements on tests of item recognition, followed by remember-know responses and associative recognition. Supporting previous research, bilateral eye movements enhanced item recognition by increasing the hit rate and decreasing the false alarm rate. Analysis of remember-know responses indicated that eye movement effects were accompanied by increases in remember responses. The test of associative recognition found that bilateral eye movements increased correct responses to intact pairs and decreased false alarms to rearranged pairs. Experiment 2 assessed the effects of eye movements on the recall of intrinsic (color) and extrinsic (spatial location) context. Bilateral eye movements increased correct recall for both types of context. The results are discussed within the framework of dual-process models of memory and the possible neural underpinnings of these effects are considered.

Eye movements and postural control in dyslexic children performing different visual tasks.

PubMed

Razuk, Milena; Barela, José Angelo; Peyre, Hugo; Gerard, Christophe Loic; Bucci, Maria Pia

2018-01-01

The aim of this study was to examine eye movements and postural control performance among dyslexic children while reading a text and performing the Landolt reading task. Fifteen dyslexic and 15 non-dyslexic children were asked to stand upright while performing two experimental visual tasks: text reading and Landolt reading. In the text reading task, children were asked to silently read a text displayed on a monitor, while in the Landolt reading task, the letters in the text were replaced by closed circles and Landolt rings, and children were asked to scan each circle/ring in a reading-like fashion, from left to right, and to count the number of Landolt rings. Eye movements (Mobile T2®, SuriCog) and center of pressure excursions (Framiral®, Grasse, France) were recorded. Visual performance variables were total reading time, mean duration of fixation, number of pro- and retro-saccades, and amplitude of pro-saccades. Postural performance variable was the center of pressure area. The results showed that dyslexic children spent more time reading the text and had a longer duration of fixation than non-dyslexic children. However, no difference was observed between dyslexic and non-dyslexic children in the Landolt reading task. Dyslexic children performed a higher number of pro- and retro-saccades than non-dyslexic children in both text reading and Landolt reading tasks. Dyslexic children had smaller pro-saccade amplitude than non-dyslexic children in the text reading task. Finally, postural performance was poorer in dyslexic children than in non-dyslexic children. Reading difficulties in dyslexic children are related to eye movement strategies required to scan and obtain lexical and semantic meaning. However, postural control performance, which was poor in dyslexic children, is not related to lexical and semantic reading requirements and might not also be related to different eye movement behavior.

Gaze stability of observers watching Op Art pictures.

PubMed

Zanker, Johannes M; Doyle, Melanie; Robin, Walker

2003-01-01

It has been the matter of some debate why we can experience vivid dynamic illusions when looking at static pictures composed from simple black and white patterns. The impression of illusory motion is particularly strong when viewing some of the works of 'Op Artists, such as Bridget Riley's painting Fall. Explanations of the illusory motion have ranged from retinal to cortical mechanisms, and an important role has been attributed to eye movements. To assess the possible contribution of eye movements to the illusory-motion percept we studied the strength of the illusion under different viewing conditions, and analysed the gaze stability of observers viewing the Riley painting and control patterns that do not produce the illusion. Whereas the illusion was reduced, but not abolished, when watching the painting through a pinhole, which reduces the effects of accommodation, it was not perceived in flash afterimages, suggesting an important role for eye movements in generating the illusion for this image. Recordings of eye movements revealed an abundance of small involuntary saccades when looking at the Riley pattern, despite the fact that gaze was kept within the dedicated fixation region. The frequency and particular characteristics of these rapid eye movements can vary considerably between different observers, but, although there was a tendency for gaze stability to deteriorate while viewing a Riley painting, there was no significant difference in saccade frequency between the stimulus and control patterns. Theoretical considerations indicate that such small image displacements can generate patterns of motion signals in a motion-detector network, which may serve as a simple and sufficient, but not necessarily exclusive, explanation for the illusion. Why such image displacements lead to perceptual results with a group of Op Art and similar patterns, but remain invisible for other stimuli, is discussed.

Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study.

PubMed

Causer, Joe; Harvey, Adrian; Snelgrove, Ryan; Arsenault, Gina; Vickers, Joan N

2014-08-01

We examined the effectiveness of technical training (TT) and quiet eye training (QE) on the performance of one-handed square knot tying in surgical residents. Twenty surgical residents were randomly assigned to the 2 groups and completed pretest, training, retention, and transfer tests. Participants wore a mobile eye tracker that simultaneously recorded their gaze and hand movements. Dependent variables were knot tying performance (%), QE duration (%), number of fixations, total movement time (s), and hand movement phase time (s). The QE training group had significantly higher performance scores, a longer QE duration, fewer fixations, faster total knot tying times, and faster movement phase times compared with the TT group. The QE group maintained performance in the transfer test, whereas the TT group significantly decreased performance from retention to transfer. QE training significantly improved learning, retention, and transfer of surgical knot tying compared with a traditional technical approach. Both performance effectiveness (performance outcome) and movement efficiency (hand movement times) were improved using QE modeling, instruction, and feedback. Copyright © 2014 Elsevier Inc. All rights reserved.

Magnetic eye tracking in mice

PubMed Central

Payne, Hannah L

2017-01-01

Eye movements provide insights about a wide range of brain functions, from sensorimotor integration to cognition; hence, the measurement of eye movements is an important tool in neuroscience research. We describe a method, based on magnetic sensing, for measuring eye movements in head-fixed and freely moving mice. A small magnet was surgically implanted on the eye, and changes in the magnet angle as the eye rotated were detected by a magnetic field sensor. Systematic testing demonstrated high resolution measurements of eye position of <0.1°. Magnetic eye tracking offers several advantages over the well-established eye coil and video-oculography methods. Most notably, it provides the first method for reliable, high-resolution measurement of eye movements in freely moving mice, revealing increased eye movements and altered binocular coordination compared to head-fixed mice. Overall, magnetic eye tracking provides a lightweight, inexpensive, easily implemented, and high-resolution method suitable for a wide range of applications. PMID:28872455

Relationship Between Eye Movement and Cognitive Information Acquisition Utilizing an Unobtrusive Eye Movement Monitoring Device.

ERIC Educational Resources Information Center

Nesbit, Larry L.

A research study was designed to test the relationship between the number of eye fixations and amount of learning as determined by a criterion referenced posttest. The study sought to answer the following questions: (1) Are differences in eye movement indices related to the posttest score? (2) Do differences in eye movement indices of subjects…

Transcranial magnetic stimulation over the cerebellum delays predictive head movements in the coordination of gaze.

PubMed

Zangemeister, W H; Nagel, M

2001-01-01

We investigated coordinated saccadic eye and head movements following predictive horizontal visual targets at +/- 30 degrees by applying transcranial magnetic stimulation (TMS) over the cerebellum before the start of the gaze movement in 10 young subjects. We found three effects of TMS on eye-head movements: 1. Saccadic latency effect. When stimulation took place shortly before movements commenced (75-25 ms before), significantly shorter latencies were found between predictive target presentation and initiation of saccades. Eye latencies were significantly decreased by 45 ms on average, but head latencies were not. 2. Gaze amplitude effect. Without TMS, for the 60 degrees target amplitudes, head movements usually preceded eye movements, as expected (predictive gaze type 3). With TMS 5-75 ms before the gaze movement, the number of eye movements preceding head movements by 20-50 ms was significantly increased (p < 0.001) and the delay between eye and head movements was reversed (p < 0.001), i.e. we found eye-predictive gaze type 1. 3. Saccadic peak velocity effect. For TMS 5-25 s before the start of head movement, mean peak velocity of synkinetic eye saccades increased by 20-30% up to 600 degrees/s, compared to 350-400 degrees/s without TMS. We conclude that transient functional cerebellar deficits exerted by means of TMS can change the central synkinesis of eye-head coordination, including the preprogramming of the saccadic pulse and step of a coordinated gaze movement.

Distinct eye movement patterns enhance dynamic visual acuity.

PubMed

Palidis, Dimitrios J; Wyder-Hodge, Pearson A; Fooken, Jolande; Spering, Miriam

2017-01-01

Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics-eye latency, acceleration, velocity gain, position error-and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns-minimizing eye position error, tracking smoothly, and inhibiting reverse saccades-were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA.

Distinct eye movement patterns enhance dynamic visual acuity

PubMed Central

Palidis, Dimitrios J.; Wyder-Hodge, Pearson A.; Fooken, Jolande; Spering, Miriam

2017-01-01

Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. PMID:28187157

Visual exploration during locomotion limited by fear of heights.

PubMed

Kugler, Günter; Huppert, Doreen; Eckl, Maria; Schneider, Erich; Brandt, Thomas

2014-01-01

Visual exploration of the surroundings during locomotion at heights has not yet been investigated in subjects suffering from fear of heights. Eye and head movements were recorded separately in 16 subjects susceptible to fear of heights and in 16 non-susceptible controls while walking on an emergency escape balcony 20 meters above ground level. Participants wore mobile infrared eye-tracking goggles with a head-fixed scene camera and integrated 6-degrees-of-freedom inertial sensors for recording head movements. Video recordings of the subjects were simultaneously made to correlate gaze and gait behavior. Susceptibles exhibited a limited visual exploration of the surroundings, particularly the depth. Head movements were significantly reduced in all three planes (yaw, pitch, and roll) with less vertical head oscillations, whereas total eye movements (saccade amplitudes, frequencies, fixation durations) did not differ from those of controls. However, there was an anisotropy, with a preference for the vertical as opposed to the horizontal direction of saccades. Comparison of eye and head movement histograms and the resulting gaze-in-space revealed a smaller total area of visual exploration, which was mainly directed straight ahead and covered vertically an area from the horizon to the ground in front of the feet. This gaze behavior was associated with a slow, cautious gait. The visual exploration of the surroundings by susceptibles to fear of heights differs during locomotion at heights from the earlier investigated behavior of standing still and looking from a balcony. During locomotion, anisotropy of gaze-in-space shows a preference for the vertical as opposed to the horizontal direction during stance. Avoiding looking into the abyss may reduce anxiety in both conditions; exploration of the "vertical strip" in the heading direction is beneficial for visual control of balance and avoidance of obstacles during locomotion.

Eye movements during the Rorschach test in schizophrenia.

PubMed

Hori, Yasuko; Fukuzako, Hiroshi; Sugimoto, Yoko; Takigawa, Morikuni

2002-08-01

In order to understand relationships between scanning behaviors, characteristics of visual stimuli and the clinical symptoms in schizophrenia, eye movements of 37 schizophrenic patients and 36 controls were recorded using an eye-mark recorder during a free-response period in a Rorschach test. Four cards (I, II, V and VIII) were used. Data were analyzed during 15 s from the presentation of each card. For all cards, the number of eye fixations and the number of eye fixation areas were fewer, and total scanning length and mean scanning length were shorter for schizophrenic patients than for controls. For card II, in the non-popular response group, eye fixation frequency upon area 5 + 6 (red) was higher for schizophrenic patients. For card VIII, in the popular response group, eye fixation frequency upon area 5 + 6 (pink) was lower for schizophrenic patients. For cards II and VIII, the number of eye fixations was inversely correlated with negative symptoms. For card II, total scanning length tended to be inversely correlated with negative symptoms, and mean eye fixation time was correlated with negative symptoms. The number of eye fixation areas was inversely correlated with positive symptoms. For card VIII, eye fixation frequency in a stimulative area tended to be correlated with positive symptoms. Scanning behaviors in schizophrenic patients are affected by characteristics of visual stimuli, and partially by clinical symptoms.

Adaptive Acceleration of Visually Evoked Smooth Eye Movements in Mice

PubMed Central

2016-01-01

The optokinetic response (OKR) consists of smooth eye movements following global motion of the visual surround, which suppress image slip on the retina for visual acuity. The effective performance of the OKR is limited to rather slow and low-frequency visual stimuli, although it can be adaptably improved by cerebellum-dependent mechanisms. To better understand circuit mechanisms constraining OKR performance, we monitored how distinct kinematic features of the OKR change over the course of OKR adaptation, and found that eye acceleration at stimulus onset primarily limited OKR performance but could be dramatically potentiated by visual experience. Eye acceleration in the temporal-to-nasal direction depended more on the ipsilateral floccular complex of the cerebellum than did that in the nasal-to-temporal direction. Gaze-holding following the OKR was also modified in parallel with eye-acceleration potentiation. Optogenetic manipulation revealed that synchronous excitation and inhibition of floccular complex Purkinje cells could effectively accelerate eye movements in the nasotemporal and temporonasal directions, respectively. These results collectively delineate multiple motor pathways subserving distinct aspects of the OKR in mice and constrain hypotheses regarding cellular mechanisms of the cerebellum-dependent tuning of movement acceleration. SIGNIFICANCE STATEMENT Although visually evoked smooth eye movements, known as the optokinetic response (OKR), have been studied in various species for decades, circuit mechanisms of oculomotor control and adaptation remain elusive. In the present study, we assessed kinematics of the mouse OKR through the course of adaptation training. Our analyses revealed that eye acceleration at visual-stimulus onset primarily limited working velocity and frequency range of the OKR, yet could be dramatically potentiated during OKR adaptation. Potentiation of eye acceleration exhibited different properties between the nasotemporal and temporonasal OKRs, indicating distinct visuomotor circuits underlying the two. Lesions and optogenetic manipulation of the cerebellum provide constraints on neural circuits mediating visually driven eye acceleration and its adaptation. PMID:27335412

An Integrative Model for the Neural Mechanism of Eye Movement Desensitization and Reprocessing (EMDR).

PubMed

Coubard, Olivier A

2016-01-01

Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, 26 years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in post-traumatic stress disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons why the scientific community is still divided about EMDR. I then slide from psychology to physiology describing eye movements/emotion interaction from the physiological viewpoint, and introduce theoretical and technical tools used in movement research to re-examine EMDR neural mechanism. Using a recent physiological model for the neuropsychological architecture of motor and cognitive control, the Threshold Interval Modulation with Early Release-Rate of rIse Deviation with Early Release (TIMER-RIDER)-model, I explore how attentional control and bilateral stimulation may participate to EMDR effects. These effects may be obtained by two processes acting in parallel: (i) activity level enhancement of attentional control component; and (ii) bilateral stimulation in any sensorimotor modality, both resulting in lower inhibition enabling dysfunctional information to be processed and anxiety to be reduced. The TIMER-RIDER model offers quantitative predictions about EMDR effects for future research about its underlying physiological mechanisms.

Pramipexole in the treatment of REM sleep behaviour disorder: A critical review.

PubMed

Tan, Shian Ming; Wan, Yi Min

2016-09-30

While widely accepted as a first-line treatment for rapid eye movement sleep (REM) behaviour disorder, clonazepam (CNZP) has side effects that limit its applicability. Pramipexole is a possible alternative, but limited literature on its effectiveness exists. This review aims to summarize the available data on the use of pramipexole in REM sleep behaviour disorder. A systematic search of major databases was conducted to look for published and on-going trials. This search yielded a total of five articles, all of which are observational in nature. Factors associated with effectiveness include low doses (less than 1.5mg/day) and idiopathic rapid eye movement sleep behaviour disorder/absence of neurodegenerative disease. Overall, the evidence is inconclusive. This is due to the lack of randomised controlled trials and the challenges in interpreting polysomgraphy findings in rapid eye movement sleep behaviour disorder. Suggestions are given on how future trials evaluating pramipexole treatment in rapid eye movement sleep behaviour disorder could overcome current methodological issues in extant literature. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Young children with autism spectrum disorder use predictive eye movements in action observation.

PubMed

Falck-Ytter, Terje

2010-06-23

Does a dysfunction in the mirror neuron system (MNS) underlie the social symptoms defining autism spectrum disorder (ASD)? Research suggests that the MNS matches observed actions to motor plans for similar actions, and that these motor plans include directions for predictive eye movements when observing goal-directed actions. Thus, one important question is whether children with ASD use predictive eye movements in action observation. Young children with ASD as well as typically developing children and adults were shown videos in which an actor performed object-directed actions (human agent condition). Children with ASD were also shown control videos showing objects moving by themselves (self-propelled condition). Gaze was measured using a corneal reflection technique. Children with ASD and typically developing individuals used strikingly similar goal-directed eye movements when observing others' actions in the human agent condition. Gaze was reactive in the self-propelled condition, suggesting that prediction is linked to seeing a hand-object interaction. This study does not support the view that ASD is characterized by a global dysfunction in the MNS.

Effects of handedness & saccadic bilateral eye movements on the specificity of past autobiographical memory & episodic future thinking.

PubMed

Parker, Andrew; Parkin, Adam; Dagnall, Neil

2017-06-01

The present research investigated the effects of personal handedness and saccadic eye movements on the specificity of past autobiographical memory and episodic future thinking. Handedness and saccadic eye movements have been hypothesised to share a common functional basis in that both influence cognition through hemispheric interaction. The technique used to elicit autobiographical memory and episodic future thought involved a cued sentence completion procedure that allowed for the production of memories spanning the highly specific to the very general. Experiment 1 found that mixed-handed (vs. right handed) individuals generated more specific past autobiographical memories, but equivalent numbers of specific future predictions. Experiment 2 demonstrated that following 30s of bilateral (horizontal) saccades, more specific cognitions about both the past and future were generated. These findings extend previous research by showing that more distinct and episodic-like information pertaining to the self can be elicited by either mixed-handedness or eye movements. The results are discussed in relation to hemispheric interaction and top-down influences in the control of memory retrieval. Copyright © 2017 Elsevier Inc. All rights reserved.

21 CFR 886.1510 - Eye movement monitor.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Eye movement monitor. 886.1510 Section 886.1510...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1510 Eye movement monitor. (a) Identification. An eye movement monitor is an AC-powered device with an electrode intended to measure and record...

21 CFR 886.1510 - Eye movement monitor.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Eye movement monitor. 886.1510 Section 886.1510...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1510 Eye movement monitor. (a) Identification. An eye movement monitor is an AC-powered device with an electrode intended to measure and record...

A Review on Eye Movement Studies in Childhood and Adolescent Psychiatry

ERIC Educational Resources Information Center

Rommelse, Nanda N. J.; Van der Stigchel, Stefan; Sergeant, Joseph A.

2008-01-01

The neural substrates of eye movement measures are largely known. Therefore, measurement of eye movements in psychiatric disorders may provide insight into the underlying neuropathology of these disorders. Visually guided saccades, antisaccades, memory guided saccades, and smooth pursuit eye movements will be reviewed in various childhood…

Spatial constancy mechanisms in motor control

PubMed Central

Medendorp, W. Pieter

2011-01-01

The success of the human species in interacting with the environment depends on the ability to maintain spatial stability despite the continuous changes in sensory and motor inputs owing to movements of eyes, head and body. In this paper, I will review recent advances in the understanding of how the brain deals with the dynamic flow of sensory and motor information in order to maintain spatial constancy of movement goals. The first part summarizes studies in the saccadic system, showing that spatial constancy is governed by a dynamic feed-forward process, by gaze-centred remapping of target representations in anticipation of and across eye movements. The subsequent sections relate to other oculomotor behaviour, such as eye–head gaze shifts, smooth pursuit and vergence eye movements, and their implications for feed-forward mechanisms for spatial constancy. Work that studied the geometric complexities in spatial constancy and saccadic guidance across head and body movements, distinguishing between self-generated and passively induced motion, indicates that both feed-forward and sensory feedback processing play a role in spatial updating of movement goals. The paper ends with a discussion of the behavioural mechanisms of spatial constancy for arm motor control and their physiological implications for the brain. Taken together, the emerging picture is that the brain computes an evolving representation of three-dimensional action space, whose internal metric is updated in a nonlinear way, by optimally integrating noisy and ambiguous afferent and efferent signals. PMID:21242137

Psychomotor control in a virtual laparoscopic surgery training environment: gaze control parameters differentiate novices from experts.

PubMed

Wilson, Mark; McGrath, John; Vine, Samuel; Brewer, James; Defriend, David; Masters, Richard

2010-10-01

Surgical simulation is increasingly used to facilitate the adoption of technical skills during surgical training. This study sought to determine if gaze control parameters could differentiate between the visual control of experienced and novice operators performing an eye-hand coordination task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Typically adopted hand movement metrics reflect only one half of the eye-hand coordination relationship; therefore, little is known about how hand movements are guided and controlled by vision. A total of 14 right-handed surgeons were categorised as being either experienced (having led more than 70 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The eight experienced and six novice surgeons completed the eye-hand coordination task from the LAP Mentor basic skills package while wearing a gaze registration system. A variety of performance, movement, and gaze parameters were recorded and compared between groups. The experienced surgeons completed the task significantly more quickly than the novices, but only the economy of movement of the left tool differentiated skill level from the LAP Mentor parameters. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. The findings of the study provide support for the utility of assessing strategic gaze behaviour to better understand the way in which surgeons utilise visual information to plan and control tool movements in a virtual reality laparoscopic environment. It is hoped that by better understanding the limitations of the psychomotor system, effective gaze training programs may be developed.

Psychomotor control in a virtual laparoscopic surgery training environment: gaze control parameters differentiate novices from experts

PubMed Central

McGrath, John; Vine, Samuel; Brewer, James; Defriend, David; Masters, Richard

2010-01-01

Background Surgical simulation is increasingly used to facilitate the adoption of technical skills during surgical training. This study sought to determine if gaze control parameters could differentiate between the visual control of experienced and novice operators performing an eye-hand coordination task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Typically adopted hand movement metrics reflect only one half of the eye-hand coordination relationship; therefore, little is known about how hand movements are guided and controlled by vision. Methods A total of 14 right-handed surgeons were categorised as being either experienced (having led more than 70 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The eight experienced and six novice surgeons completed the eye-hand coordination task from the LAP Mentor basic skills package while wearing a gaze registration system. A variety of performance, movement, and gaze parameters were recorded and compared between groups. Results The experienced surgeons completed the task significantly more quickly than the novices, but only the economy of movement of the left tool differentiated skill level from the LAP Mentor parameters. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. Conclusion The findings of the study provide support for the utility of assessing strategic gaze behaviour to better understand the way in which surgeons utilise visual information to plan and control tool movements in a virtual reality laparoscopic environment. It is hoped that by better understanding the limitations of the psychomotor system, effective gaze training programs may be developed. PMID:20333405

Visual and vestibular induced eye movements in verbal children and adults with autism

PubMed Central

Furman, Joseph M.; Osorio, Maria Joana; Minshew, Nancy J.

2016-01-01

This study investigated several types of eye movements that rely on the function of brainstem-cerebellar pathways specifically (vestibular-ocular reflexes) or on widely distributed pathways of the brain (horizontal pursuit and saccade eye movements). Although eye movements that rely on higher brain regions have been studies fairly extensively in autism, eye movements dependent on brainstem and cerebellum have not. This study involved 79 individuals with autism and 62 typical controls aged 5 to 52 years with IQ scores above 70. No differences between the autism and control groups were present on the measures of vestibular ocular reflexes, or on saccade velocity or accuracy. The autism group was significantly slower to initiate saccades, which was most prominent in the 8-18 year old age range. These findings provide the most substantial evidence to date of the functional integrity of brainstem and cerebellar pathways in autism, suggesting that the histopathological abnormalities described in these structures may not be associated with intrinsic dysfunction but rather reflect developmental alterations related to forebrain cortical systems formation. The increase in saccade latency adds to the substantial evidence of altered function and maturation of cortical systems in autism. Objective This study assessed the functionality of vestibular, pursuit and saccade circuitry in autism across a wide age range. Methods Subjects were 79 individuals with autism (AUT) and 62 controls (CON) aged 5 to 52 years with IQ scores > 70. For vestibular testing, earth-vertical axis rotation was performed in darkness and in a lighted visual surround with a fixation target. Ocular motor testing included assessment of horizontal saccades and horizontal smooth pursuit. Results No between-group differences were found in vestibular reflexes or in mean saccade velocity or accuracy. Saccade latency was increased in the AUT group with significant age-related effects in the 8-18 year old subgroups. There was a trend toward decreased pursuit gain without age effects. Conclusions Normal vestibular-induced eye movements and normal saccade accuracy and velocity provide the most substantial evidence to date of the functional integrity of brainstem and cerebellar pathways in autism, suggesting that the histopathological abnormalities described in these structures may not be associated with intrinsic dysfunction but rather reflect developmental alterations related to forebrain cortical systems formation. Increased saccade latency with age effects adds to the extensive existing evidence of altered function and maturation of cortical systems in autism. PMID:25846907

Can Changes in Eye Movement Scanning Alter the Age-Related Deficit in Recognition Memory?

PubMed Central

Chan, Jessica P. K.; Kamino, Daphne; Binns, Malcolm A.; Ryan, Jennifer D.

2011-01-01

Older adults typically exhibit poorer face recognition compared to younger adults. These recognition differences may be due to underlying age-related changes in eye movement scanning. We examined whether older adults’ recognition could be improved by yoking their eye movements to those of younger adults. Participants studied younger and older faces, under free viewing conditions (bases), through a gaze-contingent moving window (own), or a moving window which replayed the eye movements of a base participant (yoked). During the recognition test, participants freely viewed the faces with no viewing restrictions. Own-age recognition biases were observed for older adults in all viewing conditions, suggesting that this effect occurs independently of scanning. Participants in the bases condition had the highest recognition accuracy, and participants in the yoked condition were more accurate than participants in the own condition. Among yoked participants, recognition did not depend on age of the base participant. These results suggest that successful encoding for all participants requires the bottom-up contribution of peripheral information, regardless of the locus of control of the viewer. Although altering the pattern of eye movements did not increase recognition, the amount of sampling of the face during encoding predicted subsequent recognition accuracy for all participants. Increased sampling may confer some advantages for subsequent recognition, particularly for people who have declining memory abilities. PMID:21687460

Eye movement desensitization and reprocessing therapy in subsyndromal bipolar patients with a history of traumatic events: a randomized, controlled pilot-study.

PubMed

Novo, Patricia; Landin-Romero, Ramon; Radua, Joaquim; Vicens, Victor; Fernandez, Isabel; Garcia, Francisca; Pomarol-Clotet, Edith; McKenna, Peter J; Shapiro, Francine; Amann, Benedikt L

2014-09-30

Traumatic events are frequent in bipolar patients and can worsen the course of the disease. Psychotherapeutic interventions for these events have not been studied so far. Twenty DSM-IV bipolar I and II patients with subsyndromal mood symptoms and a history of traumatic events were randomly assigned to Eye Movement Desensitization and Reprocessing therapy (n=10) or treatment as usual (n=10). The treatment group received between 14 and 18 Eye Movement Desensitization and Reprocessing sessions during 12 weeks. Evaluations of affective symptoms, symptoms of trauma and trauma impact were carried out by a blind rater at baseline, 2 weeks, 5 weeks, 8 weeks, 12 weeks and at 24 weeks follow-up. Patients in the treatment group showed a statistically significant improvement in depressive and hypomanic symptoms, symptoms of trauma and trauma impact compared to the treatment as usual group after intervention. This effect was only partly maintained in trauma impact at the 24 weeks follow-up visit. One patient dropped from Eye Movement Desensitization and Reprocessing group whereas four from the treatment as usual group. This pilot study suggests that Eye Movement Desensitization and Reprocessing therapy may be an effective and safe intervention to treat subsyndromal mood and trauma symptoms in traumatized bipolar patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Vestibulospinal control of reflex and voluntary head movement

NASA Technical Reports Server (NTRS)

Boyle, R.; Peterson, B. W. (Principal Investigator)

2001-01-01

Secondary canal-related vestibulospinal neurons respond to an externally applied movement of the head in the form of a firing rate modulation that encodes the angular velocity of the movement, and reflects in large part the input "head velocity in space" signal carried by the semicircular canal afferents. In addition to the head velocity signal, the vestibulospinal neurons can carry a more processed signal that includes eye position or eye velocity, or both (see Boyle on ref. list). To understand the control signals used by the central vestibular pathways in the generation of reflex head stabilization, such as the vestibulocollic reflex (VCR), and the maintenance of head posture, it is essential to record directly from identified vestibulospinal neurons projecting to the cervical spinal segments in the alert animal. The present report discusses two key features of the primate vestibulospinal system. First, the termination morphology of vestibulospinal axons in the cervical segments of the spinal cord is described to lay the structural basis of vestibulospinal control of head/neck posture and movement. And second, the head movement signal content carried by the same class of secondary vestibulospinal neurons during the actual execution of the VCR and during self-generated, or active, rapid head movements is presented.

Comparison of smooth pursuit and combined eye-head tracking in human subjects with deficient labyrinthine function

NASA Technical Reports Server (NTRS)

Leigh, R. J.; Thurston, S. E.; Sharpe, J. A.; Ranalli, P. J.; Hamid, M. A.

1987-01-01

The effects of deficient labyrinthine function on smooth visual tracking with the eyes and head were investigated, using ten patients with bilateral peripheral vestibular disease and ten normal controls. Active, combined eye-head tracking (EHT) was significantly better in patients than smooth pursuit with the eyes alone, whereas normal subjects pursued equally well in both cases. Compensatory eye movements during active head rotation in darkness were always less in patients than in normal subjects. These data were used to examine current hypotheses that postulate central cancellation of the vestibulo-ocular reflex (VOR) during EHT. A model that proposes summation of an integral smooth pursuit command and VOR/compensatory eye movements is consistent with the findings. Observation of passive EHT (visual fixation of a head-fixed target during en bloc rotation) appears to indicate that in this mode parametric gain changes contribute to modulation of the VOR.

Lateral eye-movement responses to visual stimuli.

PubMed

Wilbur, M P; Roberts-Wilbur, J

1985-08-01

The association of left lateral eye-movement with emotionality or arousal of affect and of right lateral eye-movement with cognitive/interpretive operations and functions was investigated. Participants were junior and senior students enrolled in an undergraduate course in developmental psychology. There were 37 women and 13 men, ranging from 19 to 45 yr. of age. Using videotaped lateral eye-movements of 50 participants' responses to 15 visually presented stimuli (precategorized as neutral, emotional, or intellectual), content and statistical analyses supported the association between left lateral eye-movement and emotional arousal and between right lateral eye-movement and cognitive functions. Precategorized visual stimuli included items such as a ball (neutral), gun (emotional), and calculator (intellectual). The findings are congruent with existing lateral eye-movement literature and also are additive by using visual stimuli that do not require the explicit response or implicit processing of verbal questioning.

Effects of background motion on eye-movement information.

PubMed

Nakamura, S

1997-02-01

The effect of background stimulus on eye-movement information was investigated by analyzing the underestimation of the target velocity during pursuit eye movement (Aubert-Fleishl paradox). In the experiment, a striped pattern with various brightness contrasts and spatial frequencies was used as a background stimulus, which was moved at various velocities. Analysis showed that the perceived velocity of the pursuit target, which indicated the magnitudes of eye-movement information, decreased when the background stripes moved in the same direction as eye movement at higher velocities and increased when the background moved in the opposite direction. The results suggest that the eye-movement information varied as a linear function of the velocity of the motion of the background retinal image (optic flow). In addition, the effectiveness of optic flow on eye-movement information was determined by the attributes of the background stimulus such as the brightness contrast or the spatial frequency of the striped pattern.

Eye movement identification based on accumulated time feature

NASA Astrophysics Data System (ADS)

Guo, Baobao; Wu, Qiang; Sun, Jiande; Yan, Hua

2017-06-01

Eye movement is a new kind of feature for biometrical recognition, it has many advantages compared with other features such as fingerprint, face, and iris. It is not only a sort of static characteristics, but also a combination of brain activity and muscle behavior, which makes it effective to prevent spoofing attack. In addition, eye movements can be incorporated with faces, iris and other features recorded from the face region into multimode systems. In this paper, we do an exploring study on eye movement identification based on the eye movement datasets provided by Komogortsev et al. in 2011 with different classification methods. The time of saccade and fixation are extracted from the eye movement data as the eye movement features. Furthermore, the performance analysis was conducted on different classification methods such as the BP, RBF, ELMAN and SVM in order to provide a reference to the future research in this field.

Getting Ahead of Oneself: Anticipation and the Vestibulo-ocular Reflex (VOR)

PubMed Central

King, W. Michael

2014-01-01

Compensatory counter-rotations of the eyes provoked by head turns are commonly attributed to the vestibulo-ocular reflex (VOR). A recent study in guinea pigs demonstrates, however, that this assumption is not always valid. During voluntary head turns, guinea pigs make highly accurate compensatory eye movements that occur with zero or even negative latencies with respect to the onset of the provoking head movements. Furthermore, the anticipatory eye movements occur in animals with bilateral peripheral vestibular lesions, thus confirming that they have an extra vestibular origin. This discovery suggests the possibility that anticipatory responses might also occur in other species including humans and non-human primates, but have been overlooked and mistakenly identified as being produced by the VOR. This review will compare primate and guinea pig vestibular physiology in light of these new findings. A unified model of vestibular and cerebellar pathways will be presented that is consistent with current data in primates and guinea pigs. The model is capable of accurately simulating compensatory eye movements to active head turns (anticipatory responses) and to passive head perturbations (VOR induced eye movements) in guinea pigs and in human subjects who use coordinated eye and head movements to shift gaze direction in space. Anticipatory responses provide new evidence and opportunities to study the role of extra vestibular signals in motor control and sensory-motor transformations. Exercises that employ voluntary head turns are frequently used to improve visual stability in patients with vestibular hypofunction. Thus, a deeper understanding of the origin and physiology of anticipatory responses could suggest new translational approaches to rehabilitative training of patients with bilateral vestibular loss. PMID:23370320

Nitric oxide facilitates GABAergic neurotransmission in the cat oculomotor system: a physiological mechanism in eye movement control

PubMed Central

Moreno-López, Bernardo; Escudero, Miguel; Estrada, Carmen

2002-01-01

Nitric oxide (NO) synthesis by prepositus hypoglossi (PH) neurons is necessary for the normal performance of horizontal eye movements. We have previously shown that unilateral injections of NO synthase (NOS) inhibitors into the PH nucleus of alert cats produce velocity imbalance without alteration of the eye position control, both during spontaneous eye movements and the vestibulo-ocular reflex (VOR). This NO effect is exerted on the dorsal PH neuropil, whose fibres increase their cGMP content when stimulated by NO. In an attempt to determine whether NO acts by modulation of a specific neurotransmission system, we have now compared the oculomotor effects of NOS inhibition with those produced by local blockade of glutamatergic, GABAergic or glycinergic receptors in the PH nucleus of alert cats. Both glutamatergic antagonists used, 2-amino-5-phosphonovaleric acid (APV) and 2,3-dihydro-6-nitro-7-sulphamoyl-benzo quinoxaline (NBQX), induced a nystagmus contralateral to that observed upon NOS inhibition, and caused exponential eye position drift. In contrast, bicuculline and strychnine induced eye velocity alterations similar to those produced by NOS inhibitors, suggesting that NO oculomotor effects were due to facilitation of some inhibitory input to the PH nucleus. To investigate the anatomical location of the putative NO target neurons, the retrograde tracer Fast Blue was injected in one PH nucleus, and the brainstem sections containing Fast Blue-positive neurons were stained with double immunohistochemistry for NO-sensitive cGMP and glutamic acid decarboxylase. GABAergic neurons projecting to the PH nucleus and containing NO-sensitive cGMP were found almost exclusively in the ipsilateral medial vestibular nucleus and marginal zone. The results suggest that the nitrergic PH neurons control their own firing rate by a NO-mediated facilitation of GABAergic afferents from the ipsilateral medial vestibular nucleus. This self-control mechanism could play an important role in the maintenance of the vestibular balance necessary to generate a stable and adequate eye position signal. PMID:11927688

A review on eye movement studies in childhood and adolescent psychiatry.

PubMed

Rommelse, Nanda N J; Van der Stigchel, Stefan; Sergeant, Joseph A

2008-12-01

The neural substrates of eye movement measures are largely known. Therefore, measurement of eye movements in psychiatric disorders may provide insight into the underlying neuropathology of these disorders. Visually guided saccades, antisaccades, memory guided saccades, and smooth pursuit eye movements will be reviewed in various childhood psychiatric disorders. The four aims of this review are (1) to give a thorough overview of eye movement studies in a wide array of psychiatric disorders occurring during childhood and adolescence (attention-deficit/hyperactivity disorder, oppositional deviant disorder and conduct disorder, autism spectrum disorders, reading disorder, childhood-onset schizophrenia, Tourette's syndrome, obsessive compulsive disorder, and anxiety and depression), (2) to discuss the specificity and overlap of eye movement findings across disorders and paradigms, (3) to discuss the developmental aspects of eye movement abnormalities in childhood and adolescence psychiatric disorders, and (4) to present suggestions for future research. In order to make this review of interest to a broad audience, attention will be given to the clinical manifestation of the disorders and the theoretical background of the eye movement paradigms.

Biometric recognition via texture features of eye movement trajectories in a visual searching task.

PubMed

Li, Chunyong; Xue, Jiguo; Quan, Cheng; Yue, Jingwei; Zhang, Chenggang

2018-01-01

Biometric recognition technology based on eye-movement dynamics has been in development for more than ten years. Different visual tasks, feature extraction and feature recognition methods are proposed to improve the performance of eye movement biometric system. However, the correct identification and verification rates, especially in long-term experiments, as well as the effects of visual tasks and eye trackers' temporal and spatial resolution are still the foremost considerations in eye movement biometrics. With a focus on these issues, we proposed a new visual searching task for eye movement data collection and a new class of eye movement features for biometric recognition. In order to demonstrate the improvement of this visual searching task being used in eye movement biometrics, three other eye movement feature extraction methods were also tested on our eye movement datasets. Compared with the original results, all three methods yielded better results as expected. In addition, the biometric performance of these four feature extraction methods was also compared using the equal error rate (EER) and Rank-1 identification rate (Rank-1 IR), and the texture features introduced in this paper were ultimately shown to offer some advantages with regard to long-term stability and robustness over time and spatial precision. Finally, the results of different combinations of these methods with a score-level fusion method indicated that multi-biometric methods perform better in most cases.

Biometric recognition via texture features of eye movement trajectories in a visual searching task

PubMed Central

Li, Chunyong; Xue, Jiguo; Quan, Cheng; Yue, Jingwei

2018-01-01

Biometric recognition technology based on eye-movement dynamics has been in development for more than ten years. Different visual tasks, feature extraction and feature recognition methods are proposed to improve the performance of eye movement biometric system. However, the correct identification and verification rates, especially in long-term experiments, as well as the effects of visual tasks and eye trackers’ temporal and spatial resolution are still the foremost considerations in eye movement biometrics. With a focus on these issues, we proposed a new visual searching task for eye movement data collection and a new class of eye movement features for biometric recognition. In order to demonstrate the improvement of this visual searching task being used in eye movement biometrics, three other eye movement feature extraction methods were also tested on our eye movement datasets. Compared with the original results, all three methods yielded better results as expected. In addition, the biometric performance of these four feature extraction methods was also compared using the equal error rate (EER) and Rank-1 identification rate (Rank-1 IR), and the texture features introduced in this paper were ultimately shown to offer some advantages with regard to long-term stability and robustness over time and spatial precision. Finally, the results of different combinations of these methods with a score-level fusion method indicated that multi-biometric methods perform better in most cases. PMID:29617383

Hypothesis test for synchronization: twin surrogates revisited.

PubMed

Romano, M Carmen; Thiel, Marco; Kurths, Jürgen; Mergenthaler, Konstantin; Engbert, Ralf

2009-03-01

The method of twin surrogates has been introduced to test for phase synchronization of complex systems in the case of passive experiments. In this paper we derive new analytical expressions for the number of twins depending on the size of the neighborhood, as well as on the length of the trajectory. This allows us to determine the optimal parameters for the generation of twin surrogates. Furthermore, we determine the quality of the twin surrogates with respect to several linear and nonlinear statistics depending on the parameters of the method. In the second part of the paper we perform a hypothesis test for phase synchronization in the case of experimental data from fixational eye movements. These miniature eye movements have been shown to play a central role in neural information processing underlying the perception of static visual scenes. The high number of data sets (21 subjects and 30 trials per person) allows us to compare the generated twin surrogates with the "natural" surrogates that correspond to the different trials. We show that the generated twin surrogates reproduce very well all linear and nonlinear characteristics of the underlying experimental system. The synchronization analysis of fixational eye movements by means of twin surrogates reveals that the synchronization between the left and right eye is significant, indicating that either the centers in the brain stem generating fixational eye movements are closely linked, or, alternatively that there is only one center controlling both eyes.

The Circadian Clock Gene Csnk1e Regulates Rapid Eye Movement Sleep Amount, and Nonrapid Eye Movement Sleep Architecture in Mice

PubMed Central

Zhou, Lili; Bryant, Camron D.; Loudon, Andrew; Palmer, Abraham A.; Vitaterna, Martha Hotz; Turek, Fred W.

2014-01-01

Study Objectives: Efforts to identify the genetic basis of mammalian sleep have included quantitative trait locus (QTL) mapping and gene targeting of known core circadian clock genes. We combined three different genetic approaches to identify and test a positional candidate sleep gene — the circadian gene casein kinase 1 epsilon (Csnk1e), which is located in a QTL we identified for rapid eye movement (REM) sleep on chromosome 15. Measurements and Results: Using electroencephalographic (EEG) and electromyographic (EMG) recordings, baseline sleep was examined in a 12-h light:12-h dark (LD 12:12) cycle in mice of seven genotypes, including Csnk1etau/tau and Csnk1e-/- mutant mice, Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice, and their respective wild-type littermate control mice. Additionally, Csnk1etau/tau and wild-type mice were examined in constant darkness (DD). Csnk1etau/tau mutant mice and both Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice showed significantly higher proportion of sleep time spent in REM sleep during the dark period than wild-type controls — the original phenotype for which the QTL on chromosome 15 was identified. This phenotype persisted in Csnk1etau/tau mice while under free-running DD conditions. Other sleep phenotypes observed in Csnk1etau/tau mice and congenics included a decreased number of bouts of nonrapid eye movement (NREM) sleep and an increased average NREM sleep bout duration. Conclusions: These results demonstrate a role for Csnk1e in regulating not only the timing of sleep, but also the REM sleep amount and NREM sleep architecture, and support Csnk1e as a causal gene in the sleep QTL on chromosome 15. Citation: Zhou L; Bryant CD; Loudon A; Palmer AA; Vitaterna MH; Turek FW. The circadian clock gene Csnk1e regulates rapid eye movement sleep amount, and nonrapid eye movement sleep architecture in mice. SLEEP 2014;37(4):785-793. PMID:24744456

Eye Movement Patterns of the Elderly during Stair Descent:Effect of Illumination

NASA Astrophysics Data System (ADS)

Kasahara, Satoko; Okabe, Sonoko; Nakazato, Naoko; Ohno, Yuko

The relationship between the eye movement pattern during stair descent and illumination was studied in 4 elderly people in comparison with that in 5 young people. The illumination condition was light (85.0±30.9 lx) or dark (0.7±0.3 lx), and data of eye movements were obtained using an eye mark recorder. A flight of 15 steps was used for the experiment, and data on 3 steps in the middle, on which the descent movements were stabilized, were analyzed. The elderly subjects pointed their eyes mostly directly in front in the facial direction regardless of the illumination condition, but the young subjects tended to look down under the light condition. The young subjects are considered to have confirmed the safety of the front by peripheral vision, checked the stepping surface by central vision, and still maintained the upright position without leaning forward during stair descent. The elderly subjects, in contrast, always looked at the visual target by central vision even under the light condition and leaned forward. The range of eye movements was larger vertically than horizontally in both groups, and a characteristic eye movement pattern of repeating a vertical shuttle movement synchronous with descent of each step was observed. Under the dark condition, the young subjects widened the range of vertical eye movements and reduced duration of fixation. The elderly subjects showed no change in the range of eye movements but increased duration of fixation during stair descent. These differences in the eye movements are considered to be compensatory reactions to narrowing of the vertical visual field, reduced dark adaptation, and reduced dynamic visual acuity due to aging. These characteristics of eye movements of the elderly lead to an anteriorly leaned posture and lack of attention to the front during stair descent.

Fetal Eye Movements on Magnetic Resonance Imaging

PubMed Central

Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C.; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

2013-01-01

Objectives Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Methods Dynamic SSFP sequences were acquired in 72 singleton fetuses (17–40 GW, three age groups [17–23 GW, 24–32 GW, 33–40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. Results In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3–45%. Conclusions In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations. PMID:24194885

Evidence that non-dreamers do dream: a REM sleep behaviour disorder model.

PubMed

Herlin, Bastien; Leu-Semenescu, Smaranda; Chaumereuil, Charlotte; Arnulf, Isabelle

2015-12-01

To determine whether non-dreamers do not produce dreams or do not recall them, subjects were identified with no dream recall with dreamlike behaviours during rapid eye movement sleep behaviour disorder, which is typically characterised by dream-enacting behaviours congruent with sleep mentation. All consecutive patients with idiopathic rapid eye movement sleep behaviour disorder or rapid eye movement sleep behaviour disorder associated with Parkinson's disease who underwent a video-polysomnography were interviewed regarding the presence or absence of dream recall, retrospectively or upon spontaneous arousals. The patients with no dream recall for at least 10 years, and never-ever recallers were compared with dream recallers with rapid eye movement sleep behaviour disorder regarding their clinical, cognitive and sleep features. Of the 289 patients with rapid eye movement sleep behaviour disorder, eight (2.8%) patients had no dream recall, including four (1.4%) patients who had never ever recalled dreams, and four patients who had no dream recall for 10-56 years. All non-recallers exhibited, daily or almost nightly, several complex, scenic and dreamlike behaviours and speeches, which were also observed during rapid eye movement sleep on video-polysomnography (arguing, fighting and speaking). They did not recall a dream following sudden awakenings from rapid eye movement sleep. These eight non-recallers with rapid eye movement sleep behaviour disorder did not differ in terms of cognition, clinical, treatment or sleep measures from the 17 dreamers with rapid eye movement sleep behaviour disorder matched for age, sex and disease. The scenic dreamlike behaviours reported and observed during rapid eye movement sleep in the rare non-recallers with rapid eye movement sleep behaviour disorder (even in the never-ever recallers) provide strong evidence that non-recallers produce dreams, but do not recall them. Rapid eye movement sleep behaviour disorder provides a new model to evaluate cognitive processing during dreaming and subsequent recall. © 2015 European Sleep Research Society.

System identification of perilymphatic fistula in an animal model

NASA Technical Reports Server (NTRS)

Wall, C. 3rd; Casselbrant, M. L.

1992-01-01

An acute animal model has been developed in the chinchilla for the study of perilymphatic fistulas. Micropunctures were made in three sites to simulate bony, round window, and oval window fistulas. The eye movements in response to pressure applied to the external auditory canal were recorded after micropuncture induction and in preoperative controls. The main pressure stimulus was a pseudorandom binary sequence (PRBS) that rapidly changed between plus and minus 200 mm of water. The PRBS stimulus, with its wide frequency bandwidth, produced responses clearly above the preoperative baseline in 78 percent of the runs. The response was better between 0.5 and 3.3 Hz than it was below 0.5 Hz. The direction of horizontal eye movement was toward the side of the fistula with positive pressure applied in 92 percent of the runs. Vertical eye movements were also observed. The ratio of vertical eye displacement to horizontal eye displacement depended upon the site of the micropuncture induction. Thus, such a ratio measurement may be clinically useful in the noninvasive localization of perilymphatic fistulas in humans.

Saccadic Eye Movement Improves Plantar Sensation and Postural Balance in Elderly Women.

PubMed

Bae, Youngsook

2016-06-01

Vision, proprioception and plantar sensation contribute to the control of postural balance (PB). Reduced plantar sensation alters postural response and is at an increased risk of fall, and eye movements reduce the postural sway. Therefore, the aim of this study was to study the improvement of plantar sensation and PB after saccadic eye movement (SEM) and pursuit eye movement (PEM) in community-dwelling elderly women. Participants (104 females; 75.11 ± 6.25 years) were randomly allocated into the SEM group (n = 52) and PEM groups (n = 52). The SEM group performed eye fixation and SEM for 5 minutes, and the PEM group performed eye fixation and PEM for 5 minutes. The plantar sensation was measured according to the plantar surface area of the feet in contact with the floor surface before and after the intervention. Before and after SEM and PEM with the eyes open and closed, PB was measured as the area (mm(2)), length (cm), and velocity (cm/s) of the fluctuation of the center of pressure (COP). The plantar sensation of both feet improved in both groups (p < 0.01). Significant decreases in the area, length, and velocity of the COP were observed in the eye open and close in both groups (p < 0.01). The length and velocity of the COP significantly decreased in the SEM group compared to the PEM group (p < 0.05). In conclusion, SEM and PEM are effective interventions for improving plantar sensation and PB in elderly women, with greater PB improvement after SEM.

Sensory and motor properties of the cerebellar uvula and modulus

NASA Technical Reports Server (NTRS)

Robinson, F. R.

1985-01-01

The uvula and nodulus (vermal lobules 9 and 10) of the vestibulocerebellum are implicated by behavioral evidence in the control of eye and head movements and in the production of motion sickness. The uvula and nodulus could play a role in these functions through known output pathways. Purkinje cells in both structures project via the fastigial and vestibular nuceli to the ventral horn of the cervical spin cord, to oculomotor neurons, and to the emetic region of the reticular formation (ablation of which abolishes susceptability to motion sickness). Uvula and nodulus Purkinje cells will be analyzed in cats trained to make controlled head movements. The activity of these neurons is expected to modulate well during head and/or eye movements because the uvula and nodulus receive heavy projections from sources of visual, vestibular and neck proprioceptive information. How neuron activity contributes to movement and how different sensory inputs converge to influence this contribution may be determined by characterizing movement related properties of these neurons. A population of neurons that modulates powerfully to the conflict between different head movement signals that can cause motion sickness may be identified.

Overlapping neural circuits for visual attention and eye movements in the human cerebellum.

PubMed

Striemer, Christopher L; Chouinard, Philippe A; Goodale, Melvyn A; de Ribaupierre, Sandrine

2015-03-01

Previous research in patients with cerebellar damage suggests that the cerebellum plays a role in covert visual attention. One limitation of some of these studies is that they examined patients with heterogeneous cerebellar damage. As a result, the patterns of reported deficits have been inconsistent. In the current study, we used functional neuroimaging (fMRI) in healthy adults (N=14) to examine whether or not the cerebellum plays a role in covert visual attention. Participants performed two covert attention tasks in which they were cued exogenously (with peripheral flashes) or endogenously (using directional arrows) to attend to marked locations in the visual periphery without moving their eyes. We compared BOLD activation in these covert attention conditions to a number of control conditions including: the same attention tasks with eye movements, a target detection task with no cueing, and a self-paced button-press task. Subtracting these control conditions from the covert attention conditions allowed us to effectively remove the contribution of the cerebellum to motor output. In addition to the usual fronto-parietal networks commonly engaged by these attention tasks, lobule VI of the vermis in the cerebellum was also activated when participants performed the covert attention tasks with or without eye movements. Interestingly, this effect was larger for exogenous compared to endogenous cueing. These results, in concert with recent patient studies, provide independent yet converging evidence that the same cerebellar structures that are involved in eye movements are also involved in visuospatial attention. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamic coding of vertical facilitated vergence by premotor saccadic burst neurons.

PubMed

Van Horn, Marion R; Cullen, Kathleen E

2008-10-01

To redirect our gaze in three-dimensional space we frequently combine saccades and vergence. These eye movements, known as disconjugate saccades, are characterized by eyes rotating by different amounts, with markedly different dynamics, and occur whenever gaze is shifted between near and far objects. How the brain ensures the precise control of binocular positioning remains controversial. It has been proposed that the traditionally assumed "conjugate" saccadic premotor pathway does not encode conjugate commands but rather encodes monocular commands for the right or left eye during saccades. Here, we directly test this proposal by recording from the premotor neurons of the horizontal saccade generator during a dissociation task that required a vergence but no horizontal conjugate saccadic command. Specifically, saccadic burst neurons (SBNs) in the paramedian pontine reticular formation were recorded while rhesus monkeys made vertical saccades made between near and far targets. During this task, we first show that peak vergence velocities were enhanced to saccade-like speeds (e.g., >150 vs. <100 degrees/s during saccade-free movements for comparable changes in vergence angle). We then quantified the discharge dynamics of SBNs during these movements and found that the majority of the neurons preferentially encode the velocity of the ipsilateral eye. Notably, a given neuron typically encoded the movement of the same eye during horizontal saccades that were made in depth. Taken together, our findings demonstrate that the brain stem saccadic burst generator encodes integrated conjugate and vergence commands, thus providing strong evidence for the proposal that the classic saccadic premotor pathway controls gaze in three-dimensional space.

Dynamic modulation of ocular orientation during visually guided saccades and smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Hess, Bernhard J M.; Angelaki, Dora E.

2003-01-01

Rotational disturbances of the head about an off-vertical yaw axis induce a complex vestibuloocular reflex pattern that reflects the brain's estimate of head angular velocity as well as its estimate of instantaneous head orientation (at a reduced scale) in space coordinates. We show that semicircular canal and otolith inputs modulate torsional and, to a certain extent, also vertical ocular orientation of visually guided saccades and smooth-pursuit eye movements in a similar manner as during off-vertical axis rotations in complete darkness. It is suggested that this graviceptive control of eye orientation facilitates rapid visual spatial orientation during motion.

Visual–Motor Transformations Within Frontal Eye Fields During Head-Unrestrained Gaze Shifts in the Monkey

PubMed Central

Sajad, Amirsaman; Sadeh, Morteza; Keith, Gerald P.; Yan, Xiaogang; Wang, Hongying; Crawford, John Douglas

2015-01-01

A fundamental question in sensorimotor control concerns the transformation of spatial signals from the retina into eye and head motor commands required for accurate gaze shifts. Here, we investigated these transformations by identifying the spatial codes embedded in visually evoked and movement-related responses in the frontal eye fields (FEFs) during head-unrestrained gaze shifts. Monkeys made delayed gaze shifts to the remembered location of briefly presented visual stimuli, with delay serving to dissociate visual and movement responses. A statistical analysis of nonparametric model fits to response field data from 57 neurons (38 with visual and 49 with movement activities) eliminated most effector-specific, head-fixed, and space-fixed models, but confirmed the dominance of eye-centered codes observed in head-restrained studies. More importantly, the visual response encoded target location, whereas the movement response mainly encoded the final position of the imminent gaze shift (including gaze errors). This spatiotemporal distinction between target and gaze coding was present not only at the population level, but even at the single-cell level. We propose that an imperfect visual–motor transformation occurs during the brief memory interval between perception and action, and further transformations from the FEF's eye-centered gaze motor code to effector-specific codes in motor frames occur downstream in the subcortical areas. PMID:25491118

The effect of visual scanning exercises integrated into physiotherapy in patients with unilateral spatial neglect poststroke: a matched-pair randomized control trial.

PubMed

van Wyk, Andoret; Eksteen, Carina A; Rheeder, Paul

2014-01-01

Unilateral spatial neglect (USN) is a visual-perceptual disorder that entails the inability to perceive and integrate stimuli on one side of the body, resulting in the neglect of one side of the body. Stroke patients with USN present with extensive functional disability and duration of therapy input. To determine the effect of saccadic eye movement training with visual scanning exercises (VSEs) integrated with task-specific activities on USN poststroke. A matched-pair randomized control trial was conducted. Subjects were matched according to their functional activity level and allocated to either a control (n = 12) or an experimental group (n = 12). All patients received task-specific activities for a 4-week intervention period. The experimental group received saccadic eye movement training with VSE integrated with task specific activities as an "add on" intervention. Assessments were conducted weekly over the intervention period. Statistical significant difference was noted on the King-Devick Test (P = .021), Star Cancellation Test (P = .016), and Barthel Index (P = .004). Intensive saccadic eye movement training with VSE integrated with task-specific activities has a significant effect on USN in patients poststroke. Results of this study are supported by findings from previously reviewed literature in the sense that the effect of saccadic eye movement training with VSE as an intervention approach has a significant effect on the visual perceptual processing of participants with USN poststroke. The significant improved visual perceptual processing translate to significantly better visual function and ability to perform activities of daily living following the stroke. © The Author(s) 2014.

Gaze training enhances laparoscopic technical skill acquisition and multi-tasking performance: a randomized, controlled study.

PubMed

Wilson, Mark R; Vine, Samuel J; Bright, Elizabeth; Masters, Rich S W; Defriend, David; McGrath, John S

2011-12-01

The operating room environment is replete with stressors and distractions that increase the attention demands of what are already complex psychomotor procedures. Contemporary research in other fields (e.g., sport) has revealed that gaze training interventions may support the development of robust movement skills. This current study was designed to examine the utility of gaze training for technical laparoscopic skills and to test performance under multitasking conditions. Thirty medical trainees with no laparoscopic experience were divided randomly into one of three treatment groups: gaze trained (GAZE), movement trained (MOVE), and discovery learning/control (DISCOVERY). Participants were fitted with a Mobile Eye gaze registration system, which measures eye-line of gaze at 25 Hz. Training consisted of ten repetitions of the "eye-hand coordination" task from the LAP Mentor VR laparoscopic surgical simulator while receiving instruction and video feedback (specific to each treatment condition). After training, all participants completed a control test (designed to assess learning) and a multitasking transfer test, in which they completed the procedure while performing a concurrent tone counting task. Not only did the GAZE group learn more quickly than the MOVE and DISCOVERY groups (faster completion times in the control test), but the performance difference was even more pronounced when multitasking. Differences in gaze control (target locking fixations), rather than tool movement measures (tool path length), underpinned this performance advantage for GAZE training. These results suggest that although the GAZE intervention focused on training gaze behavior only, there were indirect benefits for movement behaviors and performance efficiency. Additionally, focusing on a single external target when learning, rather than on complex movement patterns, may have freed-up attentional resources that could be applied to concurrent cognitive tasks.

Differential impact of partial cortical blindness on gaze strategies when sitting and walking - an immersive virtual reality study

PubMed Central

Iorizzo, Dana B.; Riley, Meghan E.; Hayhoe, Mary; Huxlin, Krystel R.

2011-01-01

The present experiments aimed to characterize the visual performance of subjects with long-standing, unilateral cortical blindness when walking in a naturalistic, virtual environment. Under static, seated testing conditions, cortically blind subjects are known to exhibit compensatory eye movement strategies. However, they still complain of significant impairment in visual detection during navigation. To assess whether this is due to a change in compensatory eye movement strategy between sitting and walking, we measured eye and head movements in subjects asked to detect peripherally-presented, moving basketballs. When seated, cortically blind subjects detected ~80% of balls, while controls detected almost all balls. Seated blind subjects did not make larger head movements than controls, but they consistently biased their fixation distribution towards their blind hemifield. When walking, head movements were similar in the two groups, but the fixation bias decreased to the point that fixation distribution in cortically blind subjects became similar to that in controls - with one major exception: at the time of basketball appearance, walking controls looked primarily at the far ground, in upper quadrants of the virtual field of view; cortically blind subjects looked significantly more at the near ground, in lower quadrants of the virtual field. Cortically blind subjects detected only 58% of the balls when walking while controls detected ~90%. Thus, the adaptive gaze strategies adopted by cortically blind individuals as a compensation for their visual loss are strongest and most effective when seated and stationary. Walking significantly alters these gaze strategies in a way that seems to favor walking performance, but impairs peripheral target detection. It is possible that this impairment underlies the experienced difficulty of those with cortical blindness when navigating in real life. PMID:21414339

Differential impact of partial cortical blindness on gaze strategies when sitting and walking - an immersive virtual reality study.

PubMed

Iorizzo, Dana B; Riley, Meghan E; Hayhoe, Mary; Huxlin, Krystel R

2011-05-25

The present experiments aimed to characterize the visual performance of subjects with long-standing, unilateral cortical blindness when walking in a naturalistic, virtual environment. Under static, seated testing conditions, cortically blind subjects are known to exhibit compensatory eye movement strategies. However, they still complain of significant impairment in visual detection during navigation. To assess whether this is due to a change in compensatory eye movement strategy between sitting and walking, we measured eye and head movements in subjects asked to detect peripherally-presented, moving basketballs. When seated, cortically blind subjects detected ∼80% of balls, while controls detected almost all balls. Seated blind subjects did not make larger head movements than controls, but they consistently biased their fixation distribution towards their blind hemifield. When walking, head movements were similar in the two groups, but the fixation bias decreased to the point that fixation distribution in cortically blind subjects became similar to that in controls - with one major exception: at the time of basketball appearance, walking controls looked primarily at the far ground, in upper quadrants of the virtual field of view; cortically blind subjects looked significantly more at the near ground, in lower quadrants of the virtual field. Cortically blind subjects detected only 58% of the balls when walking while controls detected ∼90%. Thus, the adaptive gaze strategies adopted by cortically blind individuals as a compensation for their visual loss are strongest and most effective when seated and stationary. Walking significantly alters these gaze strategies in a way that seems to favor walking performance, but impairs peripheral target detection. It is possible that this impairment underlies the experienced difficulty of those with cortical blindness when navigating in real life. Copyright © 2011 Elsevier Ltd. All rights reserved.

Narrative comprehension and production in children with SLI: An eye movement study

PubMed Central

ANDREU, LLORENÇ; SANZ-TORRENT, MONICA; OLMOS, JOAN GUÀRDIA; MACWHINNEY, BRIAN

2014-01-01

This study investigates narrative comprehension and production in children with specific language impairment (SLI). Twelve children with SLI (mean age 5; 8 years) and 12 typically developing children (mean age 5; 6 years) participated in an eye-tracking experiment designed to investigate online narrative comprehension and production in Catalan- and Spanish-speaking children with SLI. The comprehension task involved the recording of eye movements during the visual exploration of successive scenes in a story, while listening to the associated narrative. With regard to production, the children were asked to retell the story, while once again looking at the scenes, as their eye movements were monitored. During narrative production, children with SLI look at the most semantically relevant areas of the scenes fewer times than their age-matched controls, but no differences were found in narrative comprehension. Moreover, the analyses of speech productions revealed that children with SLI retained less information and made more semantic and syntactic errors during retelling. Implications for theories that characterize SLI are discussed. PMID:21453036

Modeling the Scheduling of Eye Movements and Manual Responses in Performing a Sequence of Discrete Tasks

NASA Technical Reports Server (NTRS)

Wu, Shu-Chieh; Remington, Roger W.; Lewis, Richard

2006-01-01

Common tasks in daily life are often accomplished by a sequence of actions that interleave information acquisition through the eyes and action execution by the hands. How are eye movements coordinated with the release of manual responses and how may their coordination be represented at the level of component mental operations? We have previously presented data from a typing-like task requiring separate choice responses to a series of five stimuli. We found a consistent pattern of results in both motor and ocular timing, and hypothesized possible relationships among underlying components. Here we report a model of that task, which demonstrates how the observed timing of eye movements to successive stimuli could be accounted for by assuming systems: an open-loop system generating saccades at a periodic rate, and a closed-loop system commanding a saccade based on stimulus processing. We relate this model to models of reading and discuss the motivation for dual control.

ECEM (eye closure eye movements): integrating aspects of EMDR with hypnosis for treatment of trauma.

PubMed

Hollander, H E; Bender, S S

2001-01-01

The paper addresses distinctions between hypnotic interventions and Eye Movement Desensitizing and Reprocessing (EMDR) and discusses their effect on persons who have symptoms of Posttraumatic Stress Disorder (PTSD). Eye movements in hypnosis and EMDR are considered in terms of the different ways they may affect responses in treatment. A treatment intervention within hypnosis called ECEM (Eye Closure, Eye Movements) is described. ECEM can be used for patients with histories of trauma who did not benefit adequately from either interventions in hypnosis or the EMDR treatment protocol used separately. In ECEM the eye movement variable of EMDR is integrated within a hypnosis protocol to enhance benefits of hypnosis and reduce certain risks of EMDR.

Prevalence and phenomenology of eye tics in Gilles de la Tourette syndrome.

PubMed

Martino, Davide; Cavanna, Andrea E; Robertson, Mary M; Orth, Michael

2012-10-01

Eye tics seem to be common in Gilles de la Tourette syndrome (GTS). We analyzed the frequency and clinical characteristics of eye tics in 212 GTS patients. Of the 212 patients, 201 (94.8 %) reported eye tics in their life-time; 166 (78.3 %) reported eye movement tics (rolling eyes up/down, eyes looking sideways, staring), and 194 (91.5 %) eyelid/eyebrow movement tics (frowning, raising eyebrows, blinking or winking). Patients with eye movement tics were younger at age of GTS onset (7.1 ± 4 years) than those without (8.9 ± 6.8; p = 0.024). Tic severity positively correlated to lifetime history of eye and/or eyelid/eyebrow movement tics. Our data confirm that eye and eyelid/eyebrow movement tics are very common in GTS, and most patients have several types of eye tics over time. Eye tic phenomenology was similar in patients with or without co-morbidity. Eye tics are therefore likely to be a core feature of GTS and should be routinely evaluated in order to strengthen the clinician's confidence in diagnosing GTS.

The functions of the proprioceptors of the eye muscles.

PubMed Central

Donaldson, I M

2000-01-01

This article sets out to present a fairly comprehensive review of our knowledge about the functions of the receptors that have been found in the extraocular muscles--the six muscles that move each eye of vertebrates in its orbit--of all the animals in which they have been sought, including Man. Since their discovery at the beginning of the 20th century these receptors have, at various times, been credited with important roles in the control of eye movement and the construction of extrapersonal space and have also been denied any function whatsoever. Experiments intended to study the actions of eye muscle receptors and, even more so, opinions (and indeed polemic) derived from these observations have been influenced by the changing fashions and beliefs about the more general question of how limb position and movement is detected by the brain and which signals contribute to those aspects of this that are perceived (kinaesthesis). But the conclusions drawn from studies on the eye have also influenced beliefs about the mechanisms of kinaesthesis and, arguably, this influence has been even larger than that in the converse direction. Experimental evidence accumulated over rather more than a century is set out and discussed. It supports the view that, at the beginning of the 21st century, there are excellent grounds for believing that the receptors in the extraocular muscles are indeed proprioceptors, that is to say that the signals that they send into the brain are used to provide information about the position and movement of the eye in the orbit. It seems that this information is important in the control of eye movements of at least some types, and in the determination by the brain of the direction of gaze and the relationship of the organism to its environment. In addition, signals from these receptors in the eye muscles are seen to be necessary for the development of normal mechanisms of visual analysis in the mammalian visual cortex and for both the development and maintenance of normal visuomotor behaviour. Man is among those vertebrates to whose brains eye muscle proprioceptive signals provide information apparently used in normal sensorimotor functions; these include various aspects of perception, and of the control of eye movement. It is possible that abnormalities of the eye muscle proprioceptors and their signals may play a part in the genesis of some types of human squint (strabismus); conversely studies of patients with squint in the course of their surgical or pharmacological treatment have yielded much interesting evidence about the central actions of the proprioceptive signals from the extraocular muscles. The results of experiments on the eye have played a large part in the historical controversy, now in at least its third century, about the origin of signals that inform the brain about movement of parts of the body. Some of these results, and more of the interpretations of them, now need to be critically re-examined. The re-examination in the light of recent experiments that is presented here does not support many of the conclusions confidently drawn in the past and leads to both new insights and fresh questions about the roles of information from motor signals flowing out of the brain and that from signals from the peripheral receptors flowing into it. There remain many lacunae in our knowledge and filling some of these will, it is contended, be essential to advance our understanding further. It is argued that such understanding of eye muscle proprioception is a necessary part of the understanding of the physiology and pathophysiology of eye movement control and that it is also essential to an account of how organisms, including Man, build and maintain knowledge of their relationship to the external visual world. The eye would seem to provide a uniquely favourable system in which to study the way in which information derived within the brain about motor actions may interact with signals flowing in from peripheral receptors. The review is constructed in relatively independent sections that deal with particular topics. It ends with a fairly brief piece in which the author sets out some personal views about what has been achieved recently and what most immediately needs to be done. It also suggests some lines of study that appear to the author to be important for the future. PMID:11205338

Toward an implantable functional electrical stimulation device to correct strabismus

PubMed Central

Velez, Federico G.; Isobe, Jun; Zealear, David; Judy, Jack W.; Edgerton, V. Reggie; Patnode, Stephanie; Lee, Hyowon; Hahn, Brian T.

2010-01-01

PURPOSE To investigate the feasibility of electrically stimulating the lateral rectus muscle to recover its physiologic abduction ability in cases of complete sixth cranial (abducens) nerve palsy. METHODS In the feline lateral rectus muscle model, the effects of a charge-balanced, biphasic, current-controlled stimulus on the movement of the eye were investigated while stimulation frequency, amplitude, and pulse duration was varied. Eye deflection was measured with a force transducer. Denervated conditions were simulated by injection of botulinum toxin A. RESULTS Three chemically denervated and 4 control lateral rectus muscles were analyzed. In control lateral rectus muscles, the minimum fusion frequency was approximately 170 Hz, and the maximum evoked abduction was 27°. The minimum fusion frequency was unchanged after 4 weeks of chemical denervation. Stimulation of chemically denervated lateral rectus muscle resulted in 17° of abduction. For both innervated and chemically denervated lateral rectus muscle, frequencies greater than 175 Hz yielded very little increase in abduction. Modulating amplitude produced noticeable movement throughout the tested range (0.2 to 9 mA). CONCLUSIONS Results from the feline lateral rectus muscle showed that electrical stimulation is a feasible approach to evoke a contraction from a denervated lateral rectus muscle. The degree of denervation of the feline lateral rectus muscle was indeterminate. Varying the stimulation amplitude allowed greater eye movement. It is very likely that both frequency and amplitude must be modulated for finer control of static eye position. PMID:19375369

Human amygdala activation during rapid eye movements of rapid eye movement sleep: an intracranial study.

PubMed

Corsi-Cabrera, María; Velasco, Francisco; Del Río-Portilla, Yolanda; Armony, Jorge L; Trejo-Martínez, David; Guevara, Miguel A; Velasco, Ana L

2016-10-01

The amygdaloid complex plays a crucial role in processing emotional signals and in the formation of emotional memories. Neuroimaging studies have shown human amygdala activation during rapid eye movement sleep (REM). Stereotactically implanted electrodes for presurgical evaluation in epileptic patients provide a unique opportunity to directly record amygdala activity. The present study analysed amygdala activity associated with REM sleep eye movements on the millisecond scale. We propose that phasic activation associated with rapid eye movements may provide the amygdala with endogenous excitation during REM sleep. Standard polysomnography and stereo-electroencephalograph (SEEG) were recorded simultaneously during spontaneous sleep in the left amygdala of four patients. Time-frequency analysis and absolute power of gamma activity were obtained for 250 ms time windows preceding and following eye movement onset in REM sleep, and in spontaneous waking eye movements in the dark. Absolute power of the 44-48 Hz band increased significantly during the 250 ms time window after REM sleep rapid eye movements onset, but not during waking eye movements. Transient activation of the amygdala provides physiological support for the proposed participation of the amygdala in emotional expression, in the emotional content of dreams and for the reactivation and consolidation of emotional memories during REM sleep, as well as for next-day emotional regulation, and its possible role in the bidirectional interaction between REM sleep and such sleep disorders as nightmares, anxiety and post-traumatic sleep disorder. These results provide unique, direct evidence of increased activation of the human amygdala time-locked to REM sleep rapid eye movements. © 2016 European Sleep Research Society.

iTemplate: A template-based eye movement data analysis approach.

PubMed

Xiao, Naiqi G; Lee, Kang

2018-02-08

Current eye movement data analysis methods rely on defining areas of interest (AOIs). Due to the fact that AOIs are created and modified manually, variances in their size, shape, and location are unavoidable. These variances affect not only the consistency of the AOI definitions, but also the validity of the eye movement analyses based on the AOIs. To reduce the variances in AOI creation and modification and achieve a procedure to process eye movement data with high precision and efficiency, we propose a template-based eye movement data analysis method. Using a linear transformation algorithm, this method registers the eye movement data from each individual stimulus to a template. Thus, users only need to create one set of AOIs for the template in order to analyze eye movement data, rather than creating a unique set of AOIs for all individual stimuli. This change greatly reduces the error caused by the variance from manually created AOIs and boosts the efficiency of the data analysis. Furthermore, this method can help researchers prepare eye movement data for some advanced analysis approaches, such as iMap. We have developed software (iTemplate) with a graphic user interface to make this analysis method available to researchers.

The effect of image sharpness on quantitative eye movement data and on image quality evaluation while viewing natural images

NASA Astrophysics Data System (ADS)

Vuori, Tero; Olkkonen, Maria

2006-01-01

The aim of the study is to test both customer image quality rating (subjective image quality) and physical measurement of user behavior (eye movements tracking) to find customer satisfaction differences in imaging technologies. Methodological aim is to find out whether eye movements could be quantitatively used in image quality preference studies. In general, we want to map objective or physically measurable image quality to subjective evaluations and eye movement data. We conducted a series of image quality tests, in which the test subjects evaluated image quality while we recorded their eye movements. Results show that eye movement parameters consistently change according to the instructions given to the user, and according to physical image quality, e.g. saccade duration increased with increasing blur. Results indicate that eye movement tracking could be used to differentiate image quality evaluation strategies that the users have. Results also show that eye movements would help mapping between technological and subjective image quality. Furthermore, these results give some empirical emphasis to top-down perception processes in image quality perception and evaluation by showing differences between perceptual processes in situations when cognitive task varies.

Dissecting patterns of preparatory activity in the frontal eye fields during pursuit target selection.

PubMed

Raghavan, Ramanujan T; Joshua, Mati

2017-10-01

We investigated the composition of preparatory activity of frontal eye field (FEF) neurons in monkeys performing a pursuit target selection task. In response to the orthogonal motion of a large and a small reward target, monkeys initiated pursuit biased toward the direction of large reward target motion. FEF neurons exhibited robust preparatory activity preceding movement initiation in this task. Preparatory activity consisted of two components, ramping activity that was constant across target selection conditions, and a flat offset in firing rates that signaled the target selection condition. Ramping activity accounted for 50% of the variance in the preparatory activity and was linked most strongly, on a trial-by-trial basis, to pursuit eye movement latency rather than to its direction or gain. The offset in firing rates that discriminated target selection conditions accounted for 25% of the variance in the preparatory activity and was commensurate with a winner-take-all representation, signaling the direction of large reward target motion rather than a representation that matched the parameters of the upcoming movement. These offer new insights into the role that the frontal eye fields play in target selection and pursuit control. They show that preparatory activity in the FEF signals more strongly when to move rather than where or how to move and suggest that structures outside the FEF augment its contributions to the target selection process. NEW & NOTEWORTHY We used the smooth eye movement pursuit system to link between patterns of preparatory activity in the frontal eye fields and movement during a target selection task. The dominant pattern was a ramping signal that did not discriminate between selection conditions and was linked, on trial-by-trial basis, to movement latency. A weaker pattern was composed of a constant signal that discriminated between selection conditions but was only weakly linked to the movement parameters. Copyright © 2017 the American Physiological Society.

Direct lexical control of eye movements in reading: Evidence from a survival analysis of fixation durations

PubMed Central

Reingold, Eyal M.; Reichle, Erik D.; Glaholt, Mackenzie G.; Sheridan, Heather

2013-01-01

Participants’ eye movements were monitored in an experiment that manipulated the frequency of target words (high vs. low) as well as their availability for parafoveal processing during fixations on the pre-target word (valid vs. invalid preview). The influence of the word-frequency by preview validity manipulation on the distributions of first fixation duration was examined by using ex-Gaussian fitting as well as a novel survival analysis technique which provided precise estimates of the timing of the first discernible influence of word frequency on first fixation duration. Using this technique, we found a significant influence of word frequency on fixation duration in normal reading (valid preview) as early as 145 ms from the start of fixation. We also demonstrated an equally rapid non-lexical influence on first fixation duration as a function of initial landing position (location) on target words. The time-course of frequency effects, but not location effects was strongly influenced by preview validity, demonstrating the crucial role of parafoveal processing in enabling direct lexical control of reading fixation times. Implications for models of eye-movement control are discussed. PMID:22542804

Temporal eye movement strategies during naturalistic viewing

PubMed Central

Wang, Helena X.; Freeman, Jeremy; Merriam, Elisha P.; Hasson, Uri; Heeger, David J.

2011-01-01

The deployment of eye movements to complex spatiotemporal stimuli likely involves a variety of cognitive factors. However, eye movements to movies are surprisingly reliable both within and across observers. We exploited and manipulated that reliability to characterize observers’ temporal viewing strategies. Introducing cuts and scrambling the temporal order of the resulting clips systematically changed eye movement reliability. We developed a computational model that exhibited this behavior and provided an excellent fit to the measured eye movement reliability. The model assumed that observers searched for, found, and tracked a point-of-interest, and that this process reset when there was a cut. The model did not require that eye movements depend on temporal context in any other way, and it managed to describe eye movements consistently across different observers and two movie sequences. Thus, we found no evidence for the integration of information over long time scales (greater than a second). The results are consistent with the idea that observers employ a simple tracking strategy even while viewing complex, engaging naturalistic stimuli. PMID:22262911

On Biometrics With Eye Movements.

PubMed

Zhang, Youming; Juhola, Martti

2017-09-01

Eye movements are a relatively novel data source for biometric identification. When video cameras applied to eye tracking become smaller and more efficient, this data source could offer interesting opportunities for the development of eye movement biometrics. In this paper, we study primarily biometric identification as seen as a classification task of multiple classes, and secondarily biometric verification considered as binary classification. Our research is based on the saccadic eye movement signal measurements from 109 young subjects. In order to test the data measured, we use a procedure of biometric identification according to the one-versus-one (subject) principle. In a development from our previous research, which also involved biometric verification based on saccadic eye movements, we now apply another eye movement tracker device with a higher sampling frequency of 250 Hz. The results obtained are good, with correct identification rates at 80-90% at their best.

Acting without seeing: eye movements reveal visual processing without awareness.

PubMed

Spering, Miriam; Carrasco, Marisa

2015-04-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. Here, we review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movement. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging, and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Acting without seeing: Eye movements reveal visual processing without awareness Miriam Spering & Marisa Carrasco

PubMed Central

Spering, Miriam; Carrasco, Marisa

2015-01-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. We review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movements. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. PMID:25765322

Fixation and saliency during search of natural scenes: the case of visual agnosia.

PubMed

Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

2009-07-01

Models of eye movement control in natural scenes often distinguish between stimulus-driven processes (which guide the eyes to visually salient regions) and those based on task and object knowledge (which depend on expectations or identification of objects and scene gist). In the present investigation, the eye movements of a patient with visual agnosia were recorded while she searched for objects within photographs of natural scenes and compared to those made by students and age-matched controls. Agnosia is assumed to disrupt the top-down knowledge available in this task, and so may increase the reliance on bottom-up cues. The patient's deficit in object recognition was seen in poor search performance and inefficient scanning. The low-level saliency of target objects had an effect on responses in visual agnosia, and the most salient region in the scene was more likely to be fixated by the patient than by controls. An analysis of model-predicted saliency at fixation locations indicated a closer match between fixations and low-level saliency in agnosia than in controls. These findings are discussed in relation to saliency-map models and the balance between high and low-level factors in eye guidance.

Gaze failure, drifting eye movements, and centripetal nystagmus in cerebellar disease.

PubMed Central

Leech, J; Gresty, M; Hess, K; Rudge, P

1977-01-01

Three abnormalities of eye movement in man are described which are indicative of cerebellar system disorder, namely, centripetally beating nystagmus, failure to maintain lateral gaze either in darkness or with eye closure, and slow drifting movements of the eyes in the absence of fixation. Similar eye movement signs follow cerebellectomy in the primate and the cat. These abnormalities of eye movement, together with other signs of cerebellar disease, such as rebound alternating, and gaze paretic nystagmus, are explained by the hypothesis that the cerebellum helps to maintain lateral gaze and that brain stem mechanisms which monitor gaze position generate compensatory biases in the absence of normal cerebellar function. PMID:603785

Learning rational temporal eye movement strategies.

PubMed

Hoppe, David; Rothkopf, Constantin A

2016-07-19

During active behavior humans redirect their gaze several times every second within the visual environment. Where we look within static images is highly efficient, as quantified by computational models of human gaze shifts in visual search and face recognition tasks. However, when we shift gaze is mostly unknown despite its fundamental importance for survival in a dynamic world. It has been suggested that during naturalistic visuomotor behavior gaze deployment is coordinated with task-relevant events, often predictive of future events, and studies in sportsmen suggest that timing of eye movements is learned. Here we establish that humans efficiently learn to adjust the timing of eye movements in response to environmental regularities when monitoring locations in the visual scene to detect probabilistically occurring events. To detect the events humans adopt strategies that can be understood through a computational model that includes perceptual and acting uncertainties, a minimal processing time, and, crucially, the intrinsic costs of gaze behavior. Thus, subjects traded off event detection rate with behavioral costs of carrying out eye movements. Remarkably, based on this rational bounded actor model the time course of learning the gaze strategies is fully explained by an optimal Bayesian learner with humans' characteristic uncertainty in time estimation, the well-known scalar law of biological timing. Taken together, these findings establish that the human visual system is highly efficient in learning temporal regularities in the environment and that it can use these regularities to control the timing of eye movements to detect behaviorally relevant events.

An Integrative Model for the Neural Mechanism of Eye Movement Desensitization and Reprocessing (EMDR)

PubMed Central

Coubard, Olivier A.

2016-01-01

Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, 26 years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in post-traumatic stress disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons why the scientific community is still divided about EMDR. I then slide from psychology to physiology describing eye movements/emotion interaction from the physiological viewpoint, and introduce theoretical and technical tools used in movement research to re-examine EMDR neural mechanism. Using a recent physiological model for the neuropsychological architecture of motor and cognitive control, the Threshold Interval Modulation with Early Release-Rate of rIse Deviation with Early Release (TIMER-RIDER)—model, I explore how attentional control and bilateral stimulation may participate to EMDR effects. These effects may be obtained by two processes acting in parallel: (i) activity level enhancement of attentional control component; and (ii) bilateral stimulation in any sensorimotor modality, both resulting in lower inhibition enabling dysfunctional information to be processed and anxiety to be reduced. The TIMER-RIDER model offers quantitative predictions about EMDR effects for future research about its underlying physiological mechanisms. PMID:27092064

Feed-forward and feedback projections of midbrain reticular formation neurons in the cat

PubMed Central

Perkins, Eddie; May, Paul J.; Warren, Susan

2014-01-01

Gaze changes involving the eyes and head are orchestrated by brainstem gaze centers found within the superior colliculus (SC), paramedian pontine reticular formation (PPRF), and medullary reticular formation (MdRF). The mesencephalic reticular formation (MRF) also plays a role in gaze. It receives a major input from the ipsilateral SC and contains cells that fire in relation to gaze changes. Moreover, it provides a feedback projection to the SC and feed-forward projections to the PPRF and MdRF. We sought to determine whether these MRF feedback and feed-forward projections originate from the same or different neuronal populations by utilizing paired fluorescent retrograde tracers in cats. Specifically, we tested: 1. whether MRF neurons that control eye movements form a single population by injecting the SC and PPRF with different tracers, and 2. whether MRF neurons that control head movements form a single population by injecting the SC and MdRF with different tracers. In neither case were double labeled neurons observed, indicating that feedback and feed-forward projections originate from separate MRF populations. In both cases, the labeled reticulotectal and reticuloreticular neurons were distributed bilaterally in the MRF. However, neurons projecting to the MdRF were generally constrained to the medial half of the MRF, while those projecting to the PPRF, like MRF reticulotectal neurons, were spread throughout the mediolateral axis. Thus, the medial MRF may be specialized for control of head movements, with control of eye movements being more widespread in this structure. PMID:24454280

Feed-forward and feedback projections of midbrain reticular formation neurons in the cat.

PubMed

Perkins, Eddie; May, Paul J; Warren, Susan

2014-01-10

Gaze changes involving the eyes and head are orchestrated by brainstem gaze centers found within the superior colliculus (SC), paramedian pontine reticular formation (PPRF), and medullary reticular formation (MdRF). The mesencephalic reticular formation (MRF) also plays a role in gaze. It receives a major input from the ipsilateral SC and contains cells that fire in relation to gaze changes. Moreover, it provides a feedback projection to the SC and feed-forward projections to the PPRF and MdRF. We sought to determine whether these MRF feedback and feed-forward projections originate from the same or different neuronal populations by utilizing paired fluorescent retrograde tracers in cats. Specifically, we tested: 1. whether MRF neurons that control eye movements form a single population by injecting the SC and PPRF with different tracers, and 2. whether MRF neurons that control head movements form a single population by injecting the SC and MdRF with different tracers. In neither case were double labeled neurons observed, indicating that feedback and feed-forward projections originate from separate MRF populations. In both cases, the labeled reticulotectal and reticuloreticular neurons were distributed bilaterally in the MRF. However, neurons projecting to the MdRF were generally constrained to the medial half of the MRF, while those projecting to the PPRF, like MRF reticulotectal neurons, were spread throughout the mediolateral axis. Thus, the medial MRF may be specialized for control of head movements, with control of eye movements being more widespread in this structure.

Visuomotor control, eye movements, and steering: A unified approach for incorporating feedback, feedforward, and internal models.

PubMed

Lappi, Otto; Mole, Callum

2018-06-11

The authors present an approach to the coordination of eye movements and locomotion in naturalistic steering tasks. It is based on recent empirical research, in particular, on driver eye movements, that poses challenges for existing accounts of how we visually steer a course. They first analyze how the ideas of feedback and feedforward processes and internal models are treated in control theoretical steering models within vision science and engineering, which share an underlying architecture but have historically developed in very separate ways. The authors then show how these traditions can be naturally (re)integrated with each other and with contemporary neuroscience, to better understand the skill and gaze strategies involved. They then propose a conceptual model that (a) gives a unified account to the coordination of gaze and steering control, (b) incorporates higher-level path planning, and (c) draws on the literature on paired forward and inverse models in predictive control. Although each of these (a-c) has been considered before (also in the context of driving), integrating them into a single framework and the authors' multiple waypoint identification hypothesis within that framework are novel. The proposed hypothesis is relevant to all forms of visually guided locomotion. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Evaluating the influence of motor control on selective attention through a stochastic model: the paradigm of motor control dysfunction in cerebellar patient.

PubMed

Veneri, Giacomo; Federico, Antonio; Rufa, Alessandra

2014-01-01

Attention allows us to selectively process the vast amount of information with which we are confronted, prioritizing some aspects of information and ignoring others by focusing on a certain location or aspect of the visual scene. Selective attention is guided by two cognitive mechanisms: saliency of the image (bottom up) and endogenous mechanisms (top down). These two mechanisms interact to direct attention and plan eye movements; then, the movement profile is sent to the motor system, which must constantly update the command needed to produce the desired eye movement. A new approach is described here to study how the eye motor control could influence this selection mechanism in clinical behavior: two groups of patients (SCA2 and late onset cerebellar ataxia LOCA) with well-known problems of motor control were studied; patients performed a cognitively demanding task; the results were compared to a stochastic model based on Monte Carlo simulations and a group of healthy subjects. The analytical procedure evaluated some energy functions for understanding the process. The implemented model suggested that patients performed an optimal visual search, reducing intrinsic noise sources. Our findings theorize a strict correlation between the "optimal motor system" and the "optimal stimulus encoders."

Psychophysiological Responsivity to Script-Driven Imagery: An Exploratory Study of the Effects of Eye Movements on Public Speaking Flashforwards.

PubMed

Kearns, Michelle; Engelhard, Iris M

2015-01-01

A principle characteristic of public speaking anxiety relates to intrusive mental images of potential future disasters. Previous research has found that the self-reported emotionality of such "flashforwards" can be reduced by a cognitively demanding, dual-task (e.g., making eye movements) performed whilst holding the mental image in-mind. The outcome measure in these earlier studies was participants' self-reported emotional intensity of the mental image. The current study (N = 34) explored whether an objective measure of emotionality would yield similar results in students with public speaking anxiety. A script-driven imagery procedure was used to measure psychophysiological responsivity to an audio script depicting a feared (public speaking) scenario before and after an eye movement intervention. Relative to the control condition (imagery only), those who made eye movements whilst holding a mental image of this scenario in-mind demonstrated a significant decrease in heart rate, which acted as a measure of emotionality. These findings add to a previous body of research demonstrating the beneficial qualities of dual-tasks and their potential for treatment of both past and future-oriented anxieties.

Psychophysiological Responsivity to Script-Driven Imagery: An Exploratory Study of the Effects of Eye Movements on Public Speaking Flashforwards

PubMed Central

Kearns, Michelle; Engelhard, Iris M.

2015-01-01

A principle characteristic of public speaking anxiety relates to intrusive mental images of potential future disasters. Previous research has found that the self-reported emotionality of such “flashforwards” can be reduced by a cognitively demanding, dual-task (e.g., making eye movements) performed whilst holding the mental image in-mind. The outcome measure in these earlier studies was participants’ self-reported emotional intensity of the mental image. The current study (N = 34) explored whether an objective measure of emotionality would yield similar results in students with public speaking anxiety. A script-driven imagery procedure was used to measure psychophysiological responsivity to an audio script depicting a feared (public speaking) scenario before and after an eye movement intervention. Relative to the control condition (imagery only), those who made eye movements whilst holding a mental image of this scenario in-mind demonstrated a significant decrease in heart rate, which acted as a measure of emotionality. These findings add to a previous body of research demonstrating the beneficial qualities of dual-tasks and their potential for treatment of both past and future-oriented anxieties. PMID:26321964

A laser-based eye-tracking system.

PubMed

Irie, Kenji; Wilson, Bruce A; Jones, Richard D; Bones, Philip J; Anderson, Tim J

2002-11-01

This paper reports on the development of a new eye-tracking system for noninvasive recording of eye movements. The eye tracker uses a flying-spot laser to selectively image landmarks on the eye and, subsequently, measure horizontal, vertical, and torsional eye movements. Considerable work was required to overcome the adverse effects of specular reflection of the flying-spot from the surface of the eye onto the sensing elements of the eye tracker. These effects have been largely overcome, and the eye-tracker has been used to document eye movement abnormalities, such as abnormal torsional pulsion of saccades, in the clinical setting.

Exogenous orienting of attention depends upon the ability to execute eye movements.

PubMed

Smith, Daniel T; Rorden, Chris; Jackson, Stephen R

2004-05-04

Shifts of attention can be made overtly by moving the eyes or covertly with attention being allocated to a region of space that does not correspond to the current direction of gaze. However, the precise relationship between eye movements and the covert orienting of attention remains controversial. The influential premotor theory proposes that the covert orienting of attention is produced by the programming of (unexecuted) eye movements and thus predicts a strong relationship between the ability to execute eye movements and the operation of spatial attention. Here, we demonstrate for the first time that impaired spatial attention is observed in an individual (AI) who is neurologically healthy but who cannot execute eye movements as a result of a congenital impairment in the elasticity of her eye muscles. This finding provides direct support for the role of the eye-movement system in the covert orienting of attention and suggests that whereas intact cortical structures may be necessary for normal attentional reflexes, they are not sufficient. The ability to move our eyes is essential for the development of normal patterns of spatial attention.

The effect of sensory uncertainty due to amblyopia (lazy eye) on the planning and execution of visually-guided 3D reaching movements.

PubMed

Niechwiej-Szwedo, Ewa; Goltz, Herbert C; Chandrakumar, Manokaraananthan; Wong, Agnes M F

2012-01-01

Impairment of spatiotemporal visual processing in amblyopia has been studied extensively, but its effects on visuomotor tasks have rarely been examined. Here, we investigate how visual deficits in amblyopia affect motor planning and online control of visually-guided, unconstrained reaching movements. Thirteen patients with mild amblyopia, 13 with severe amblyopia and 13 visually-normal participants were recruited. Participants reached and touched a visual target during binocular and monocular viewing. Motor planning was assessed by examining spatial variability of the trajectory at 50-100 ms after movement onset. Online control was assessed by examining the endpoint variability and by calculating the coefficient of determination (R(2)) which correlates the spatial position of the limb during the movement to endpoint position. Patients with amblyopia had reduced precision of the motor plan in all viewing conditions as evidenced by increased variability of the reach early in the trajectory. Endpoint precision was comparable between patients with mild amblyopia and control participants. Patients with severe amblyopia had reduced endpoint precision along azimuth and elevation during amblyopic eye viewing only, and along the depth axis in all viewing conditions. In addition, they had significantly higher R(2) values at 70% of movement time along the elevation and depth axes during amblyopic eye viewing. Sensory uncertainty due to amblyopia leads to reduced precision of the motor plan. The ability to implement online corrections depends on the severity of the visual deficit, viewing condition, and the axis of the reaching movement. Patients with mild amblyopia used online control effectively to compensate for the reduced precision of the motor plan. In contrast, patients with severe amblyopia were not able to use online control as effectively to amend the limb trajectory especially along the depth axis, which could be due to their abnormal stereopsis.

The Effect of Sensory Uncertainty Due to Amblyopia (Lazy Eye) on the Planning and Execution of Visually-Guided 3D Reaching Movements

PubMed Central

Niechwiej-Szwedo, Ewa; Goltz, Herbert C.; Chandrakumar, Manokaraananthan; Wong, Agnes M. F.

2012-01-01

Background Impairment of spatiotemporal visual processing in amblyopia has been studied extensively, but its effects on visuomotor tasks have rarely been examined. Here, we investigate how visual deficits in amblyopia affect motor planning and online control of visually-guided, unconstrained reaching movements. Methods Thirteen patients with mild amblyopia, 13 with severe amblyopia and 13 visually-normal participants were recruited. Participants reached and touched a visual target during binocular and monocular viewing. Motor planning was assessed by examining spatial variability of the trajectory at 50–100 ms after movement onset. Online control was assessed by examining the endpoint variability and by calculating the coefficient of determination (R2) which correlates the spatial position of the limb during the movement to endpoint position. Results Patients with amblyopia had reduced precision of the motor plan in all viewing conditions as evidenced by increased variability of the reach early in the trajectory. Endpoint precision was comparable between patients with mild amblyopia and control participants. Patients with severe amblyopia had reduced endpoint precision along azimuth and elevation during amblyopic eye viewing only, and along the depth axis in all viewing conditions. In addition, they had significantly higher R2 values at 70% of movement time along the elevation and depth axes during amblyopic eye viewing. Conclusion Sensory uncertainty due to amblyopia leads to reduced precision of the motor plan. The ability to implement online corrections depends on the severity of the visual deficit, viewing condition, and the axis of the reaching movement. Patients with mild amblyopia used online control effectively to compensate for the reduced precision of the motor plan. In contrast, patients with severe amblyopia were not able to use online control as effectively to amend the limb trajectory especially along the depth axis, which could be due to their abnormal stereopsis. PMID:22363549

Extraocular muscle function testing

MedlinePlus

... may result in double vision or rapid, uncontrolled eye movements . Normal Results Normal movement of the eyes in all directions. What Abnormal Results Mean Eye movement disorders may be due to abnormalities of the ...

Internuclear Ophthalmoplegia

MedlinePlus

... Nerve Disorders Internuclear ophthalmoplegia is impairment of horizontal eye movements caused by damage to certain connections between nerve ... include Lyme disease, tumors, and head injuries. Horizontal eye movements are impaired, but vertical eye movements are not. ...

The relationship among eye movements, head movements, and manual responses in a simulated air traffic control task.

DOT National Transportation Integrated Search

1995-08-01

Performance of operators in aviation systems is highly dependent on their ability to visually scan information sources, identify problematic situations, and respond appropriately. Scanning behavior has often been mentioned as a contributing factor in...

Independent associations between fatty acids and sleep quality among obese patients with obstructive sleep apnoea syndrome.

PubMed

Papandreou, Christopher

2013-10-01

The aim of this study was to examine the relationships between gluteal adipose tissue fatty acids and sleep quality in obese patients with obstructive sleep apnoea syndrome after controlling for possible confounders. Sixty-three patients with obstructive sleep apnoea syndrome based on overnight attended polysomnography were included. Gluteal adipose tissue fatty acids were analysed by gas chromatography. Anthropometric measurements were carried out. Depressive symptoms were assessed by the Zung Self-rating Depression Scale. Saturated fatty acids were positively related to total sleep time, sleep efficiency and rapid eye movement sleep. Significant positive associations were found between polyunsaturated fatty acids and sleep efficiency and rapid eye movement sleep. Moreover, n-3 fatty acids were positively associated with sleep efficiency, slow wave sleep and rapid eye movement sleep. This study revealed independent associations between certain gluteal adipose tissue fatty acids and sleep quality after controlling for age, gender, obesity, obstructive sleep apnoea syndrome indices and Zung Self-rating Depression Scale scores in patients with moderate to severe obstructive sleep apnoea syndrome. © 2013 European Sleep Research Society.

Exploratory eye movements to pictures in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder (ADHD).

PubMed

Karatekin, C; Asarnow, R F

1999-02-01

We investigated exploratory eye movements to thematic pictures in schizophrenic, attention-deficit/hyperactivity disorder (ADHD), and normal children. For each picture, children were asked three questions varying in amount of structure. We tested if schizophrenic children would stare or scan extensively and if their scan patterns were differentially affected by the question. Time spent viewing relevant and irrelevant regions, fixation duration (an estimate of processing rate), and distance between fixations (an estimate of breadth of attention) were measured. ADHD children showed a trend toward shorter fixations than normals on the question requiring the most detailed analysis. Schizophrenic children looked at fewer relevant, but not more irrelevant, regions than normals. They showed a tendency to stare more when asked to decide what was happening but not when asked to attend to specific regions. Thus, lower levels of visual attention (e.g., basic control of eye movements) were intact in schizophrenic children. In contrast, they had difficulty with top-down control of selective attention in the service of self-guided behavior.

The Relation between Reading Skills and Eye Movement Patterns in Adolescent Readers: Evidence from a Regular Orthography

PubMed Central

Krieber, Magdalena; Bartl-Pokorny, Katrin D.; Pokorny, Florian B.; Einspieler, Christa; Langmann, Andrea; Körner, Christof; Falck-Ytter, Terje; Marschik, Peter B.

2016-01-01

Over the past decades, the relation between reading skills and eye movement behavior has been well documented in English-speaking cohorts. As English and German differ substantially with regard to orthographic complexity (i.e. grapheme-phoneme correspondence), we aimed to delineate specific characteristics of how reading speed and reading comprehension interact with eye movements in typically developing German-speaking (Austrian) adolescents. Eye movements of 22 participants (14 females; mean age = 13;6 years;months) were tracked while they were performing three tasks, namely silently reading words, texts, and pseudowords. Their reading skills were determined by means of a standardized German reading speed and reading comprehension assessment (Lesegeschwindigkeits- und -verständnistest für Klassen 6−12). We found that (a) reading skills were associated with various eye movement parameters in each of the three reading tasks; (b) better reading skills were associated with an increased efficiency of eye movements, but were primarily linked to spatial reading parameters, such as the number of fixations per word, the total number of saccades and saccadic amplitudes; (c) reading speed was a more reliable predictor for eye movement parameters than reading comprehension; (d) eye movements were highly correlated across reading tasks, which indicates consistent reading performances. Contrary to findings in English-speaking cohorts, the reading skills neither consistently correlated with temporal eye movement parameters nor with the number or percentage of regressions made while performing any of the three reading tasks. These results indicate that, although reading skills are associated with eye movement patterns irrespective of language, the temporal and spatial characteristics of this association may vary with orthographic consistency. PMID:26727255

Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

PubMed

Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

2011-08-01

Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e., brightness and contrast in low-level stimulus features. Here we review this approach and present new data from our own experiments with an agnosic patient that quantifies the relationship between saliency and fixation location. In addition, we consider whether the perceptual difficulties of individual patients might be modeled by selectively weighting the different features involved in a saliency map. Our data indicate that saliency is not always a good predictor of fixation in agnosia: even for our agnosic subject, as for normal observers, the saliency-fixation relationship varied as a function of the task. This means that top-down processes still have a significant effect on the earliest stages of scanning in the setting of visual agnosia, indicating severe limitations for the saliency map model. Top-down, active strategies-which are the hallmark of our human visual system-play a vital role in eye movement control, whether we know what we are looking at or not. Copyright © 2011 Elsevier Ltd. All rights reserved.

Gray matter abnormalities of the dorsal posterior cingulate in sleep walking.

PubMed

Heidbreder, Anna; Stefani, Ambra; Brandauer, Elisabeth; Steiger, Ruth; Kremser, Christian; Gizewski, Elke R; Young, Peter; Poewe, Werner; Högl, Birgit; Scherfler, Christoph

2017-08-01

This study aimed to determine whether voxel-based analysis of T1 weighted magnetic resonance imaging (MRI) and diffusion tensor imaging is able to detect alterations of gray and white matter morphometry as well as measures of mean diffusivity and fractional anisotropy in patients with non-rapid eye movement parasomnia. 3 Tesla MRI was performed in 14 drug-free, polysomnography-confirmed adult patients with non-rapid eye movement parasomnia (age: 29 ± 4.2 years; disease duration 19.2 ± 7.7 years) and 14 healthy subjects, matched for age and gender. Statistical parametric mapping was applied to objectively identify focal changes of MRI parameters throughout the entire brain volume. Statistical parametric mapping localized significant decreases of gray matter volume in the left dorsal posterior cingulate cortex (BA23) and posterior midcingulate cortex (BA24) in patients with non-rapid eye movement parasomnias compared to the control group (p < 0.001, corrected for multiple comparisons). No significant differences of mean diffusivity and fractional anisotropy measures were found between the non-rapid eye movement parasomnia group and the healthy control group. Recently, the simultaneous co-existence of arousal or wakefulness originating from the motor and cingulate cortices and persistent sleep in associative cortical regions was suggested as a functional framework of somnambulism. Gray matter volume decline in the dorsal posterior and posterior midcingulate cortex reported in this study might represent the neuroanatomical substrate for this condition. Copyright © 2017 Elsevier B.V. All rights reserved.

Eye-Hand Synergy and Intermittent Behaviors during Target-Directed Tracking with Visual and Non-visual Information

PubMed Central

Huang, Chien-Ting; Hwang, Ing-Shiou

2012-01-01

Visual feedback and non-visual information play different roles in tracking of an external target. This study explored the respective roles of the visual and non-visual information in eleven healthy volunteers who coupled the manual cursor to a rhythmically moving target of 0.5 Hz under three sensorimotor conditions: eye-alone tracking (EA), eye-hand tracking with visual feedback of manual outputs (EH tracking), and the same tracking without such feedback (EHM tracking). Tracking error, kinematic variables, and movement intermittency (saccade and speed pulse) were contrasted among tracking conditions. The results showed that EHM tracking exhibited larger pursuit gain, less tracking error, and less movement intermittency for the ocular plant than EA tracking. With the vision of manual cursor, EH tracking achieved superior tracking congruency of the ocular and manual effectors with smaller movement intermittency than EHM tracking, except that the rate precision of manual action was similar for both types of tracking. The present study demonstrated that visibility of manual consequences altered mutual relationships between movement intermittency and tracking error. The speed pulse metrics of manual output were linked to ocular tracking error, and saccade events were time-locked to the positional error of manual tracking during EH tracking. In conclusion, peripheral non-visual information is critical to smooth pursuit characteristics and rate control of rhythmic manual tracking. Visual information adds to eye-hand synchrony, underlying improved amplitude control and elaborate error interpretation during oculo-manual tracking. PMID:23236498

VisualEyes: a modular software system for oculomotor experimentation.

PubMed

Guo, Yi; Kim, Eun H; Kim, Eun; Alvarez, Tara; Alvarez, Tara L

2011-03-25

Eye movement studies have provided a strong foundation forming an understanding of how the brain acquires visual information in both the normal and dysfunctional brain.(1) However, development of a platform to stimulate and store eye movements can require substantial programming, time and costs. Many systems do not offer the flexibility to program numerous stimuli for a variety of experimental needs. However, the VisualEyes System has a flexible architecture, allowing the operator to choose any background and foreground stimulus, program one or two screens for tandem or opposing eye movements and stimulate the left and right eye independently. This system can significantly reduce the programming development time needed to conduct an oculomotor study. The VisualEyes System will be discussed in three parts: 1) the oculomotor recording device to acquire eye movement responses, 2) the VisualEyes software written in LabView, to generate an array of stimuli and store responses as text files and 3) offline data analysis. Eye movements can be recorded by several types of instrumentation such as: a limbus tracking system, a sclera search coil, or a video image system. Typical eye movement stimuli such as saccadic steps, vergent ramps and vergent steps with the corresponding responses will be shown. In this video report, we demonstrate the flexibility of a system to create numerous visual stimuli and record eye movements that can be utilized by basic scientists and clinicians to study healthy as well as clinical populations.

The interaction of Bayesian priors and sensory data and its neural circuit implementation in visually-guided movement

PubMed Central

Yang, Jin; Lee, Joonyeol; Lisberger, Stephen G.

2012-01-01

Sensory-motor behavior results from a complex interaction of noisy sensory data with priors based on recent experience. By varying the stimulus form and contrast for the initiation of smooth pursuit eye movements in monkeys, we show that visual motion inputs compete with two independent priors: one prior biases eye speed toward zero; the other prior attracts eye direction according to the past several days’ history of target directions. The priors bias the speed and direction of the initiation of pursuit for the weak sensory data provided by the motion of a low-contrast sine wave grating. However, the priors have relatively little effect on pursuit speed and direction when the visual stimulus arises from the coherent motion of a high-contrast patch of dots. For any given stimulus form, the mean and variance of eye speed co-vary in the initiation of pursuit, as expected for signal-dependent noise. This relationship suggests that pursuit implements a trade-off between movement accuracy and variation, reducing both when the sensory signals are noisy. The tradeoff is implemented as a competition of sensory data and priors that follows the rules of Bayesian estimation. Computer simulations show that the priors can be understood as direction specific control of the strength of visual-motor transmission, and can be implemented in a neural-network model that makes testable predictions about the population response in the smooth eye movement region of the frontal eye fields. PMID:23223286

Words in Context: The Effects of Length, Frequency, and Predictability on Brain Responses During Natural Reading

PubMed Central

Schuster, Sarah; Hawelka, Stefan; Hutzler, Florian; Kronbichler, Martin; Richlan, Fabio

2016-01-01

Word length, frequency, and predictability count among the most influential variables during reading. Their effects are well-documented in eye movement studies, but pertinent evidence from neuroimaging primarily stem from single-word presentations. We investigated the effects of these variables during reading of whole sentences with simultaneous eye-tracking and functional magnetic resonance imaging (fixation-related fMRI). Increasing word length was associated with increasing activation in occipital areas linked to visual analysis. Additionally, length elicited a U-shaped modulation (i.e., least activation for medium-length words) within a brain stem region presumably linked to eye movement control. These effects, however, were diminished when accounting for multiple fixation cases. Increasing frequency was associated with decreasing activation within left inferior frontal, superior parietal, and occipito-temporal regions. The function of the latter region—hosting the putative visual word form area—was originally considered as limited to sublexical processing. An exploratory analysis revealed that increasing predictability was associated with decreasing activation within middle temporal and inferior frontal regions previously implicated in memory access and unification. The findings are discussed with regard to their correspondence with findings from single-word presentations and with regard to neurocognitive models of visual word recognition, semantic processing, and eye movement control during reading. PMID:27365297

Dynamic interactions of eye and head movements when reading with single-vision and progressive lenses in a simulated computer-based environment.

PubMed

Han, Ying; Ciuffreda, Kenneth J; Selenow, Arkady; Ali, Steven R

2003-04-01

To assess dynamic interactions of eye and head movements during return-sweep saccades (RSS) when reading with single-vision (SVL) versus progressive-addition (PAL) lenses in a simulated computer-based business environment. Horizontal eye and head movements were recorded objectively and simultaneously at a rate of 60 Hz during reading of single-page (SP; 14 degrees horizontal [H]) and double-page (DP; 37 degrees H) formats at 60 cm with binocular viewing. Subjects included 11 individuals with normal presbyopic vision aged 45 to 71 years selected by convenience sampling from a clinic population. Reading was performed with three types of spectacle lenses with a different clear near field of view (FOV): a SVL (60 degrees H clear FOV), a PAL-I with a relatively wide intermediate zone (7.85 mm; 18 degrees H clear FOV), and a PAL-II with a relatively narrow intermediate zone (5.60 mm; 13 degrees H clear FOV). Eye movements were initiated before head movements in the SP condition, and the reverse was found in the DP condition, with all three lens types. Duration of eye movements increased as the zone of clear vision decreased in the SP condition, and they were longer with the PALs than with the SVL in the DP condition. Gaze stabilization occurred later with the PALs than with the SVL in both the SP and DP conditions. The duration of head movements was longer with the PAL-II than with the SVL in both the SP and DP conditions. Eye movement peak velocity was greater with the SVL than the PALs in the DP condition. Eye movement and head movement strategies and timing were contingent on viewing conditions. The longer eye movement duration and gaze-stabilization times suggested that additional eye movements were needed to locate the clear-vision zone and commence reading after the RSS. Head movements with PALs for the SP condition were similarly optically induced. These eye movement and head movement results may contribute to the reduced reading rate and related symptoms reported by some PAL wearers. The dynamic interactions of eye movements and head movements during reading with the PALs appear to be a sensitive indicator of the effect of lens optical design parameters on overall reading performance, because the movements can discriminate between SVL and PAL designs and at times even between PALs.

Eye Gaze and Aging: Selective and Combined Effects of Working Memory and Inhibitory Control.

PubMed

Crawford, Trevor J; Smith, Eleanor S; Berry, Donna M

2017-01-01

Eye-tracking is increasingly studied as a cognitive and biological marker for the early signs of neuropsychological and psychiatric disorders. However, in order to make further progress, a more comprehensive understanding of the age-related effects on eye-tracking is essential. The antisaccade task requires participants to make saccadic eye movements away from a prepotent stimulus. Speculation on the cause of the observed age-related differences in the antisaccade task largely centers around two sources of cognitive dysfunction: inhibitory control (IC) and working memory (WM). The IC account views cognitive slowing and task errors as a direct result of the decline of inhibitory cognitive mechanisms. An alternative theory considers that a deterioration of WM is the cause of these age-related effects on behavior. The current study assessed IC and WM processes underpinning saccadic eye movements in young and older participants. This was achieved with three experimental conditions that systematically varied the extent to which WM and IC were taxed in the antisaccade task: a memory-guided task was used to explore the effect of increasing the WM load; a Go/No-Go task was used to explore the effect of increasing the inhibitory load; a 'standard' antisaccade task retained the standard WM and inhibitory loads. Saccadic eye movements were also examined in a control condition: the standard prosaccade task where the load of WM and IC were minimal or absent. Saccade latencies, error rates and the spatial accuracy of saccades of older participants were compared to the same measures in healthy young controls across the conditions. The results revealed that aging is associated with changes in both IC and WM. Increasing the inhibitory load was associated with increased reaction times in the older group, while the increased WM load and the inhibitory load contributed to an increase in the antisaccade errors. These results reveal that aging is associated with changes in both IC and WM.

I Can Read It in Your Eyes: What Eye Movements Tell Us about Visuo-Attentional Processes in Developmental Dyslexia

ERIC Educational Resources Information Center

Bellocchi, Stephanie; Muneaux, Mathilde; Bastien-Toniazzo, Mireille; Ducrot, Stephanie

2013-01-01

Most studies today agree about the link between visual-attention and oculomotor control during reading: attention seems to affect saccadic programming, that is, the position where the eyes land in a word. Moreover, recent studies show that visuo-attentional processes are strictly linked to normal and impaired reading. In particular, a large body…

Combining EEG and eye movement recording in free viewing: Pitfalls and possibilities.

PubMed

Nikolaev, Andrey R; Meghanathan, Radha Nila; van Leeuwen, Cees

2016-08-01

Co-registration of EEG and eye movement has promise for investigating perceptual processes in free viewing conditions, provided certain methodological challenges can be addressed. Most of these arise from the self-paced character of eye movements in free viewing conditions. Successive eye movements occur within short time intervals. Their evoked activity is likely to distort the EEG signal during fixation. Due to the non-uniform distribution of fixation durations, these distortions are systematic, survive across-trials averaging, and can become a source of confounding. We illustrate this problem with effects of sequential eye movements on the evoked potentials and time-frequency components of EEG and propose a solution based on matching of eye movement characteristics between experimental conditions. The proposal leads to a discussion of which eye movement characteristics are to be matched, depending on the EEG activity of interest. We also compare segmentation of EEG into saccade-related epochs relative to saccade and fixation onsets and discuss the problem of baseline selection and its solution. Further recommendations are given for implementing EEG-eye movement co-registration in free viewing conditions. By resolving some of the methodological problems involved, we aim to facilitate the transition from the traditional stimulus-response paradigm to the study of visual perception in more naturalistic conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Boldness psychopathic traits predict reduced gaze toward fearful eyes in men with a history of violence.

PubMed

Gillespie, Steven M; Rotshtein, Pia; Beech, Anthony R; Mitchell, Ian J

2017-09-01

Research with developmental and adult samples has shown a relationship of psychopathic traits with reduced eye gaze. However, these relationships remained to be investigated among forensic samples. Here we examined the eye movements of male violent offenders during an emotion recognition task. Violent offenders performed similar to non-offending controls, and their eye movements varied with the emotion and intensity of the facial expression. In the violent offender group Boldness psychopathic traits, but not Meanness or Disinhibition, were associated with reduced dwell time and fixation counts, and slower first fixation latencies, on the eyes compared with the mouth. These results are the first to show a relationship of psychopathic traits with reduced attention to the eyes in a forensic sample, and suggest that Boldness is associated with difficulties in orienting attention toward emotionally salient aspects of the face. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Saccadic eye movements analysis as a measure of drug effect on central nervous system function.

PubMed

Tedeschi, G; Quattrone, A; Bonavita, V

1986-04-01

Peak velocity (PSV) and duration (SD) of horizontal saccadic eye movements are demonstrably under the control of specific brain stem structures. Experimental and clinical evidence suggest the existence of an immediate premotor system for saccade generation located in the paramedian pontine reticular formation (PPRF). Effects on saccadic eye movements have been studied in normal volunteers with barbiturates, benzodiazepines, amphetamine and ethanol. On two occasions computer analysis of PSV, SD, saccade reaction time (SRT) and saccade accuracy (SA) was carried out in comparison with more traditional methods of assessment of human psychomotor performance like choice reaction time (CRT) and critical flicker fusion threshold (CFFT). The computer system proved to be a highly sensitive and objective method for measuring drug effect on central nervous system (CNS) function. It allows almost continuous sampling of data and appears to be particularly suitable for studying rapidly changing drug effects on the CNS.

Eye movements reduce vividness and emotionality of "flashforwards".

PubMed

Engelhard, Iris M; van den Hout, Marcel A; Janssen, Wilco C; van der Beek, Jorinde

2010-05-01

Earlier studies have shown that eye movements during retrieval of disturbing images about past events reduce their vividness and emotionality, which may be due to both tasks competing for working memory resources. This study examined whether eye movements reduce vividness and emotionality of visual distressing images about feared future events: "flashforwards". A non-clinical sample was asked to select two images of feared future events, which were self-rated for vividness and emotionality. These images were retrieved while making eye movements or without a concurrent secondary task, and then vividness and emotionality were rated again. Relative to the no-dual task condition, eye movements while thinking of future-oriented images resulted in decreased ratings of image vividness and emotional intensity. Apparently, eye movements reduce vividness and emotionality of visual images about past and future feared events. This is in line with a working memory account of the beneficial effects of eye movements, which predicts that any task that taxes working memory during retrieval of disturbing mental images will be beneficial. Copyright 2010 Elsevier Ltd. All rights reserved.

Visual-Motor Transformations Within Frontal Eye Fields During Head-Unrestrained Gaze Shifts in the Monkey.

PubMed

Sajad, Amirsaman; Sadeh, Morteza; Keith, Gerald P; Yan, Xiaogang; Wang, Hongying; Crawford, John Douglas

2015-10-01

A fundamental question in sensorimotor control concerns the transformation of spatial signals from the retina into eye and head motor commands required for accurate gaze shifts. Here, we investigated these transformations by identifying the spatial codes embedded in visually evoked and movement-related responses in the frontal eye fields (FEFs) during head-unrestrained gaze shifts. Monkeys made delayed gaze shifts to the remembered location of briefly presented visual stimuli, with delay serving to dissociate visual and movement responses. A statistical analysis of nonparametric model fits to response field data from 57 neurons (38 with visual and 49 with movement activities) eliminated most effector-specific, head-fixed, and space-fixed models, but confirmed the dominance of eye-centered codes observed in head-restrained studies. More importantly, the visual response encoded target location, whereas the movement response mainly encoded the final position of the imminent gaze shift (including gaze errors). This spatiotemporal distinction between target and gaze coding was present not only at the population level, but even at the single-cell level. We propose that an imperfect visual-motor transformation occurs during the brief memory interval between perception and action, and further transformations from the FEF's eye-centered gaze motor code to effector-specific codes in motor frames occur downstream in the subcortical areas. © The Author 2014. Published by Oxford University Press.

Pursuit and prediction in the tracking of moving food by a teleost fish (Acanthaluteres spilomelanurus).

PubMed

Lanchester, B S; Mark, R F

1975-12-01

1. The path, eye and body movements of a teleost fish (the leatherjacket Acanthaluteres spilomelanurus) approaching and taking food were measured by cinematography. 2. Fixation of the food by movement of the eyes is an invariable feature of the approach. The eyes then remain aligned with the target while the body moves forward and round to bring the mouth to the food. 3. When pursuing pieces of food moving vertically at constant velocity through the water these fish normally trace out the pathway that can be calculated by assuming the fish aims constantly at the food. Predictive pathways that imply anticipation of the point of intersection with the food are not regularly seen. 4. Deviations from pursuit occur sporadically, usually in the direction of a predictive path, particularly when the fish approach falling food from below. 5. The geometry of the situation suggests that predictive paths may sometimes be generated if the alignment of eye and body during the pursuit of moving food can be delayed. In approaches from below this may be because forward movement of the fish would tend to stabilize the image of the falling food in the retina. 6. We suggest that a simple linked control system using both eye and body movements to fixate retinal images will on occasions generate predictive pathways without any need for the central nervous system to calculate them in advance.

Context effects on smooth pursuit and manual interception of a disappearing target.

PubMed

Kreyenmeier, Philipp; Fooken, Jolande; Spering, Miriam

2017-07-01

In our natural environment, we interact with moving objects that are surrounded by richly textured, dynamic visual contexts. Yet most laboratory studies on vision and movement show visual objects in front of uniform gray backgrounds. Context effects on eye movements have been widely studied, but it is less well known how visual contexts affect hand movements. Here we ask whether eye and hand movements integrate motion signals from target and context similarly or differently, and whether context effects on eye and hand change over time. We developed a track-intercept task requiring participants to track the initial launch of a moving object ("ball") with smooth pursuit eye movements. The ball disappeared after a brief presentation, and participants had to intercept it in a designated "hit zone." In two experiments ( n = 18 human observers each), the ball was shown in front of a uniform or a textured background that either was stationary or moved along with the target. Eye and hand movement latencies and speeds were similarly affected by the visual context, but eye and hand interception (eye position at time of interception, and hand interception timing error) did not differ significantly between context conditions. Eye and hand interception timing errors were strongly correlated on a trial-by-trial basis across all context conditions, highlighting the close relation between these responses in manual interception tasks. Our results indicate that visual contexts similarly affect eye and hand movements but that these effects may be short-lasting, affecting movement trajectories more than movement end points. NEW & NOTEWORTHY In a novel track-intercept paradigm, human observers tracked a briefly shown object moving across a textured, dynamic context and intercepted it with their finger after it had disappeared. Context motion significantly affected eye and hand movement latency and speed, but not interception accuracy; eye and hand position at interception were correlated on a trial-by-trial basis. Visual context effects may be short-lasting, affecting movement trajectories more than movement end points. Copyright © 2017 the American Physiological Society.

Knowing what the brain is seeing in three dimensions: A novel, noninvasive, sensitive, accurate, and low-noise technique for measuring ocular torsion.

PubMed

Otero-Millan, Jorge; Roberts, Dale C; Lasker, Adrian; Zee, David S; Kheradmand, Amir

2015-01-01

Torsional eye movements are rotations of the eye around the line of sight. Measuring torsion is essential to understanding how the brain controls eye position and how it creates a veridical perception of object orientation in three dimensions. Torsion is also important for diagnosis of many vestibular, neurological, and ophthalmological disorders. Currently, there are multiple devices and methods that produce reliable measurements of horizontal and vertical eye movements. Measuring torsion, however, noninvasively and reliably has been a longstanding challenge, with previous methods lacking real-time capabilities or suffering from intrusive artifacts. We propose a novel method for measuring eye movements in three dimensions using modern computer vision software (OpenCV) and concepts of iris recognition. To measure torsion, we use template matching of the entire iris and automatically account for occlusion of the iris and pupil by the eyelids. The current setup operates binocularly at 100 Hz with noise <0.1° and is accurate within 20° of gaze to the left, to the right, and up and 10° of gaze down. This new method can be widely applicable and fill a gap in many scientific and clinical disciplines.

Knowing what the brain is seeing in three dimensions: A novel, noninvasive, sensitive, accurate, and low-noise technique for measuring ocular torsion

PubMed Central

Otero-Millan, Jorge; Roberts, Dale C.; Lasker, Adrian; Zee, David S.; Kheradmand, Amir

2015-01-01

Torsional eye movements are rotations of the eye around the line of sight. Measuring torsion is essential to understanding how the brain controls eye position and how it creates a veridical perception of object orientation in three dimensions. Torsion is also important for diagnosis of many vestibular, neurological, and ophthalmological disorders. Currently, there are multiple devices and methods that produce reliable measurements of horizontal and vertical eye movements. Measuring torsion, however, noninvasively and reliably has been a longstanding challenge, with previous methods lacking real-time capabilities or suffering from intrusive artifacts. We propose a novel method for measuring eye movements in three dimensions using modern computer vision software (OpenCV) and concepts of iris recognition. To measure torsion, we use template matching of the entire iris and automatically account for occlusion of the iris and pupil by the eyelids. The current setup operates binocularly at 100 Hz with noise <0.1° and is accurate within 20° of gaze to the left, to the right, and up and 10° of gaze down. This new method can be widely applicable and fill a gap in many scientific and clinical disciplines. PMID:26587699

Cognitive processes involved in smooth pursuit eye movements: behavioral evidence, neural substrate and clinical correlation

PubMed Central

Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo; Barnes, Graham R.

2013-01-01

Smooth-pursuit eye movements allow primates to track moving objects. Efficient pursuit requires appropriate target selection and predictive compensation for inherent processing delays. Prediction depends on expectation of future object motion, storage of motion information and use of extra-retinal mechanisms in addition to visual feedback. We present behavioral evidence of how cognitive processes are involved in predictive pursuit in normal humans and then describe neuronal responses in monkeys and behavioral responses in patients using a new technique to test these cognitive controls. The new technique examines the neural substrate of working memory and movement preparation for predictive pursuit by using a memory-based task in macaque monkeys trained to pursue (go) or not pursue (no-go) according to a go/no-go cue, in a direction based on memory of a previously presented visual motion display. Single-unit task-related neuronal activity was examined in medial superior temporal cortex (MST), supplementary eye fields (SEF), caudal frontal eye fields (FEF), cerebellar dorsal vermis lobules VI–VII, caudal fastigial nuclei (cFN), and floccular region. Neuronal activity reflecting working memory of visual motion direction and go/no-go selection was found predominantly in SEF, cerebellar dorsal vermis and cFN, whereas movement preparation related signals were found predominantly in caudal FEF and the same cerebellar areas. Chemical inactivation produced effects consistent with differences in signals represented in each area. When applied to patients with Parkinson's disease (PD), the task revealed deficits in movement preparation but not working memory. In contrast, patients with frontal cortical or cerebellar dysfunction had high error rates, suggesting impaired working memory. We show how neuronal activity may be explained by models of retinal and extra-retinal interaction in target selection and predictive control and thus aid understanding of underlying pathophysiology. PMID:23515488

Visuomotor cerebellum in human and nonhuman primates.

PubMed

Voogd, Jan; Schraa-Tam, Caroline K L; van der Geest, Jos N; De Zeeuw, Chris I

2012-06-01

In this paper, we will review the anatomical components of the visuomotor cerebellum in human and, where possible, in non-human primates and discuss their function in relation to those of extracerebellar visuomotor regions with which they are connected. The floccular lobe, the dorsal paraflocculus, the oculomotor vermis, the uvula-nodulus, and the ansiform lobule are more or less independent components of the visuomotor cerebellum that are involved in different corticocerebellar and/or brain stem olivocerebellar loops. The floccular lobe and the oculomotor vermis share different mossy fiber inputs from the brain stem; the dorsal paraflocculus and the ansiform lobule receive corticopontine mossy fibers from postrolandic visual areas and the frontal eye fields, respectively. Of the visuomotor functions of the cerebellum, the vestibulo-ocular reflex is controlled by the floccular lobe; saccadic eye movements are controlled by the oculomotor vermis and ansiform lobule, while control of smooth pursuit involves all these cerebellar visuomotor regions. Functional imaging studies in humans further emphasize cerebellar involvement in visual reflexive eye movements and are discussed.

Premotor neurons encode torsional eye velocity during smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Angelaki, Dora E.; Dickman, J. David

2003-01-01

Responses to horizontal and vertical ocular pursuit and head and body rotation in multiple planes were recorded in eye movement-sensitive neurons in the rostral vestibular nuclei (VN) of two rhesus monkeys. When tested during pursuit through primary eye position, the majority of the cells preferred either horizontal or vertical target motion. During pursuit of targets that moved horizontally at different vertical eccentricities or vertically at different horizontal eccentricities, eye angular velocity has been shown to include a torsional component the amplitude of which is proportional to half the gaze angle ("half-angle rule" of Listing's law). Approximately half of the neurons, the majority of which were characterized as "vertical" during pursuit through primary position, exhibited significant changes in their response gain and/or phase as a function of gaze eccentricity during pursuit, as if they were also sensitive to torsional eye velocity. Multiple linear regression analysis revealed a significant contribution of torsional eye movement sensitivity to the responsiveness of the cells. These findings suggest that many VN neurons encode three-dimensional angular velocity, rather than the two-dimensional derivative of eye position, during smooth-pursuit eye movements. Although no clear clustering of pursuit preferred-direction vectors along the semicircular canal axes was observed, the sensitivity of VN neurons to torsional eye movements might reflect a preservation of similar premotor coding of visual and vestibular-driven slow eye movements for both lateral-eyed and foveate species.

High-Speed Video-Oculography for Measuring Three-Dimensional Rotation Vectors of Eye Movements in Mice

PubMed Central

Takeda, Noriaki; Uno, Atsuhiko; Inohara, Hidenori; Shimada, Shoichi

2016-01-01

Background The mouse is the most commonly used animal model in biomedical research because of recent advances in molecular genetic techniques. Studies related to eye movement in mice are common in fields such as ophthalmology relating to vision, neuro-otology relating to the vestibulo-ocular reflex (VOR), neurology relating to the cerebellum’s role in movement, and psychology relating to attention. Recording eye movements in mice, however, is technically difficult. Methods We developed a new algorithm for analyzing the three-dimensional (3D) rotation vector of eye movement in mice using high-speed video-oculography (VOG). The algorithm made it possible to analyze the gain and phase of VOR using the eye’s angular velocity around the axis of eye rotation. Results When mice were rotated at 0.5 Hz and 2.5 Hz around the earth’s vertical axis with their heads in a 30° nose-down position, the vertical components of their left eye movements were in phase with the horizontal components. The VOR gain was 0.42 at 0.5 Hz and 0.74 at 2.5 Hz, and the phase lead of the eye movement against the turntable was 16.1° at 0.5 Hz and 4.88° at 2.5 Hz. Conclusions To the best of our knowledge, this is the first report of this algorithm being used to calculate a 3D rotation vector of eye movement in mice using high-speed VOG. We developed a technique for analyzing the 3D rotation vector of eye movements in mice with a high-speed infrared CCD camera. We concluded that the technique is suitable for analyzing eye movements in mice. We also include a C++ source code that can calculate the 3D rotation vectors of the eye position from two-dimensional coordinates of the pupil and the iris freckle in the image to this article. PMID:27023859

Eye tracking detects disconjugate eye movements associated with structural traumatic brain injury and concussion.

PubMed

Samadani, Uzma; Ritlop, Robert; Reyes, Marleen; Nehrbass, Elena; Li, Meng; Lamm, Elizabeth; Schneider, Julia; Shimunov, David; Sava, Maria; Kolecki, Radek; Burris, Paige; Altomare, Lindsey; Mehmood, Talha; Smith, Theodore; Huang, Jason H; McStay, Christopher; Todd, S Rob; Qian, Meng; Kondziolka, Douglas; Wall, Stephen; Huang, Paul

2015-04-15

Disconjugate eye movements have been associated with traumatic brain injury since ancient times. Ocular motility dysfunction may be present in up to 90% of patients with concussion or blast injury. We developed an algorithm for eye tracking in which the Cartesian coordinates of the right and left pupils are tracked over 200 sec and compared to each other as a subject watches a short film clip moving inside an aperture on a computer screen. We prospectively eye tracked 64 normal healthy noninjured control subjects and compared findings to 75 trauma subjects with either a positive head computed tomography (CT) scan (n=13), negative head CT (n=39), or nonhead injury (n=23) to determine whether eye tracking would reveal the disconjugate gaze associated with both structural brain injury and concussion. Tracking metrics were then correlated to the clinical concussion measure Sport Concussion Assessment Tool 3 (SCAT3) in trauma patients. Five out of five measures of horizontal disconjugacy were increased in positive and negative head CT patients relative to noninjured control subjects. Only one of five vertical disconjugacy measures was significantly increased in brain-injured patients relative to controls. Linear regression analysis of all 75 trauma patients demonstrated that three metrics for horizontal disconjugacy negatively correlated with SCAT3 symptom severity score and positively correlated with total Standardized Assessment of Concussion score. Abnormal eye-tracking metrics improved over time toward baseline in brain-injured subjects observed in follow-up. Eye tracking may help quantify the severity of ocular motility disruption associated with concussion and structural brain injury.

Eye Tracking Detects Disconjugate Eye Movements Associated with Structural Traumatic Brain Injury and Concussion

PubMed Central

Ritlop, Robert; Reyes, Marleen; Nehrbass, Elena; Li, Meng; Lamm, Elizabeth; Schneider, Julia; Shimunov, David; Sava, Maria; Kolecki, Radek; Burris, Paige; Altomare, Lindsey; Mehmood, Talha; Smith, Theodore; Huang, Jason H.; McStay, Christopher; Todd, S. Rob; Qian, Meng; Kondziolka, Douglas; Wall, Stephen; Huang, Paul

2015-01-01

Abstract Disconjugate eye movements have been associated with traumatic brain injury since ancient times. Ocular motility dysfunction may be present in up to 90% of patients with concussion or blast injury. We developed an algorithm for eye tracking in which the Cartesian coordinates of the right and left pupils are tracked over 200 sec and compared to each other as a subject watches a short film clip moving inside an aperture on a computer screen. We prospectively eye tracked 64 normal healthy noninjured control subjects and compared findings to 75 trauma subjects with either a positive head computed tomography (CT) scan (n=13), negative head CT (n=39), or nonhead injury (n=23) to determine whether eye tracking would reveal the disconjugate gaze associated with both structural brain injury and concussion. Tracking metrics were then correlated to the clinical concussion measure Sport Concussion Assessment Tool 3 (SCAT3) in trauma patients. Five out of five measures of horizontal disconjugacy were increased in positive and negative head CT patients relative to noninjured control subjects. Only one of five vertical disconjugacy measures was significantly increased in brain-injured patients relative to controls. Linear regression analysis of all 75 trauma patients demonstrated that three metrics for horizontal disconjugacy negatively correlated with SCAT3 symptom severity score and positively correlated with total Standardized Assessment of Concussion score. Abnormal eye-tracking metrics improved over time toward baseline in brain-injured subjects observed in follow-up. Eye tracking may help quantify the severity of ocular motility disruption associated with concussion and structural brain injury. PMID:25582436

An Analysis of the Time Course of Lexical Processing During Reading

PubMed Central

Sheridan, Heather; Reichle, Erik D.

2016-01-01

Reingold, Reichle, Glaholt, and Sheridan (2012) reported a gaze-contingent eye-movement experiment in which survival-curve analyses were used to examine the effects of word frequency, the availability of parafoveal preview, and initial fixation location on the time course of lexical processing. The key results of these analyses suggest that lexical processing begins very rapidly (after approximately 120 ms), and is supported by substantial parafoveal processing (more than 100 ms). Because it is not immediately obvious that these results are congruent with the theoretical assumption that words are processed and identified in a strictly serial manner, we attempted to simulate the experiment using the E-Z Reader model of eye-movement control (Reichle, 2011). These simulations were largely consistent with the empirical results, suggesting that parafoveal processing does play an important functional role by allowing lexical processing to occur rapidly enough to mediate direct control over when the eyes move during reading. PMID:25939443

Context-dependent adaptation of visually-guided arm movements and vestibular eye movements: role of the cerebellum

NASA Technical Reports Server (NTRS)

Lewis, Richard F.

2003-01-01

Accurate motor control requires adaptive processes that correct for gradual and rapid perturbations in the properties of the controlled object. The ability to quickly switch between different movement synergies using sensory cues, referred to as context-dependent adaptation, is a subject of considerable interest at present. The potential function of the cerebellum in context-dependent adaptation remains uncertain, but the data reviewed below suggest that it may play a fundamental role in this process.

The effects of eye movements on emotional memories: using an objective measure of cognitive load

PubMed Central

van Veen, Suzanne C.; Engelhard, Iris M.; van den Hout, Marcel A.

2016-01-01

Background Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. The working memory (WM) theory explains its efficacy: recall of an aversive memory and making eye movements (EM) both produce cognitive load, and competition for the limited WM resources reduces the memory's vividness and emotionality. The present study tested several predictions from WM theory. Objective We hypothesized that 1) recall of an aversive autobiographical memory loads WM compared to no recall, and 2) recall with EM reduces the vividness, emotionality, and cognitive load of recalling the memory more than only recall or only cognitive effort (i.e., recall of an irrelevant memory with EM). Method Undergraduates (N=108) were randomly assigned to one of three conditions: 1) recall relevant memory with EM, 2) recall relevant memory without EM, and 3) recall irrelevant memory with EM. We used a random interval repetition task to measure the cognitive load of recalling the memory. Participants responded to randomly administered beeps, with or without recalling the memory. The degree to which participants slow down during recall provides an index of cognitive load. We measured the cognitive load and self-reported vividness and emotionality before, halfway through (8×24 s), and after (16×24 s) the intervention. Results Reaction times slowed down during memory recall compared to no recall. The recall relevant with EM condition showed a larger decrease in self-reported vividness and emotionality than the control conditions. The cognitive load of recalling the memory also decreased in this condition but not consistently more than in the control conditions. Conclusions Recall of an aversive memory loads WM, but drops in vividness and emotionality do not immediately reduce the cognitive load of recalling the memory. More research is needed to find objective measures that could capture changes in the quality of the memory. Highlights of the article Recall of an aversive autobiographical memory is a cognitive demanding task. The vividness and emotionality of an aversive memory decrease more after recall with eye movements than after only recall or only cognitive effort (i.e., recall of an irrelevant memory with eye movements). The cognitive load of recalling the memory does not immediately reduce after recall with eye movements compared to only recall or only cognitive effort. Intervention duration is positively related to memory effects. PMID:27387845

Eye movement control in reading unspaced text: the case of the Japanese script.

PubMed

Kajii, N; Nazir, T A; Osaka, N

2001-09-01

The present study examines the landing-site distributions of the eyes during natural reading of Japanese script: a script that mixes three different writing systems (Kanji, Hiragana, and Katakana) and that misses regular spacing between words. The results show a clear preference of the eyes to land at the beginning rather than the center of the word. In addition, it was found that the eyes land on Kanji characters more frequently than on Hiragana or Katakana characters. Further analysis for two- and three-character words indicated that the eye's landing-site distribution differs depending on type of the characters in the word: the eyes prefer to land at the word beginning only when the initial character of the word is a Kanji character. For pure Hiragana words, the proportion of initial fixations did not differ between character positions. Thus, as already indicated by Kambe (National Institute of Japanese Language Report 85 (1986) 29), the visual distinctiveness of the three Japanese scripts plays a role in guiding eye movements in reading Japanese.

The patient observer: eye-movement desensitization and reprocessing for the treatment of posttraumatic stress following childbirth.

PubMed

Stramrood, Claire A I; van der Velde, Janneke; Doornbos, Bennard; Marieke Paarlberg, K; Weijmar Schultz, Willibrord C M; van Pampus, Maria G

2012-03-01

No standard intervention with proved effectiveness is available for women with posttraumatic stress following childbirth because of insufficient research. The objective of this paper was to evaluate the possibility of using eye-movement desensitization and reprocessing treatment for women with symptoms of posttraumatic stress disorder following childbirth. The treatment is internationally recognized as one of the interventions of choice for the condition, but little is known about its effects in women who experienced the delivery as traumatic. Three women suffering from posttraumatic stress symptoms following the birth of their first child were treated with eye-movement desensitization and reprocessing during their next pregnancy. Patient A developed posttraumatic stress symptoms following the lengthy labor of her first child that ended in an emergency cesarean section after unsuccessful vacuum extraction. Patient B suffered a second degree vaginal rupture, resulting in pain and inability to engage in sexual intercourse for years. Patient C developed severe preeclampsia postpartum requiring intravenous treatment. Patients received eye-movement desensitization and reprocessing treatment during their second pregnancy, using the standard protocol. The treatment resulted in fewer posttraumatic stress symptoms and more confidence about their pregnancy and upcoming delivery compared with before the treatment. Despite delivery complications in Patient A (secondary cesarean section due to insufficient engaging of the fetal head); Patient B (second degree vaginal rupture, this time without subsequent dyspareunia); and Patient C (postpartum hemorrhage, postpartum hypertension requiring intravenous treatment), all three women looked back positively at the second delivery experience. Treatment with eye-movement desensitization and reprocessing reduced posttraumatic stress symptoms in these three women. They were all sufficiently confident to attempt vaginal birth rather than demanding an elective cesarean section. We advocate a large-scale, randomized controlled trial involving women with postpartum posttraumatic stress disorder to evaluate the effect of eye-movement desensitization and reprocessing in this patient group. © 2011, Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc.

Factors influencing the shear rate acting on silicone oil to cause silicone oil emulsification.

PubMed

Chan, Yau Kei; Cheung, Ning; Wong, David

2014-10-30

The shear force between silicone oil (SO) bubble and aqueous during eye movements may underlie the development of SO emulsification. This study examines factors that may affect such shear force induced by eye movements. A surface-modified model eye chamber was put under large-amplitude eye movements (amplitude 90°, angular velocity 360°/s, and a duration 300 ms). Agarose-made indentations were introduced to mimic the effect of encircling scleral buckle. Two SOs (1300 and 5000 centistokes [cSt]), three volumes (3, 4, and 5 mL), and two eye chambers (with and without indentation) were tested. Video recording was used to capture the movements of SO inside the model chamber under various conditions. The presence of indentation within the eye chamber significantly reduced the velocity of SO movements relative to the eye chamber movements (P < 0.001). To a lesser extent, an increase in viscosity also had a significant effect in reducing the relative movements. No significant effect was observed for the extent of SO fill in the chamber. Our experimental model suggests indentation within an eye, such as that created by scleral buckling, may have the greatest influence in reducing shear force induced by eye movements. Therefore, using an encircling scleral buckle may be similarly or more effective than using SO with higher viscosity in lowering the propensity to SO emulsification. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Eye movements when viewing advertisements

PubMed Central

Higgins, Emily; Leinenger, Mallorie; Rayner, Keith

2013-01-01

In this selective review, we examine key findings on eye movements when viewing advertisements. We begin with a brief, general introduction to the properties and neural underpinnings of saccadic eye movements. Next, we provide an overview of eye movement behavior during reading, scene perception, and visual search, since each of these activities is, at various times, involved in viewing ads. We then review the literature on eye movements when viewing print ads and warning labels (of the kind that appear on alcohol and tobacco ads), before turning to a consideration of advertisements in dynamic media (television and the Internet). Finally, we propose topics and methodological approaches that may prove to be useful in future research. PMID:24672500

Negative mental imagery in public speaking anxiety: Forming cognitive resistance by taxing visuospatial working memory.

PubMed

Homer, Sophie R; Deeprose, Catherine; Andrade, Jackie

2016-03-01

This study sought to reconcile two lines of research. Previous studies have identified a prevalent and causal role of negative imagery in social phobia and public speaking anxiety; others have demonstrated that lateral eye movements during visualisation of imagery reduce its vividness, most likely by loading the visuospatial sketchpad of working memory. It was hypothesised that using eye movements to reduce the intensity of negative imagery associated with public speaking may reduce anxiety resulting from imagining a public speaking scenario compared to an auditory control task. Forty undergraduate students scoring high in anxiety on the Personal Report of Confidence as a Speaker scale took part. A semi-structured interview established an image that represented the participant's public speaking anxiety, which was then visualised during an eye movement task or a matched auditory task. Reactions to imagining a hypothetical but realistic public speaking scenario were measured. As hypothesised, representative imagery was established and reduced in vividness more effectively by the eye movement task than the auditory task. The public speaking scenario was then visualised less vividly and generated less anxiety when imagined after performing the eye movement task than after the auditory task. Self-report measures and a hypothetical scenario rather than actual public speaking were used. Replication is required in larger as well as clinical samples. Visuospatial working memory tasks may preferentially reduce anxiety associated with personal images of feared events, and thus provide cognitive resistance which reduces emotional reactions to imagined, and potentially real-life future stressful experiences. Copyright © 2015 Elsevier Ltd. All rights reserved.

Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: an eye tracker study.

PubMed

Kasten, Erich; Bunzenthal, Ulrike; Sabel, Bernhard A

2006-11-25

It has been argued that patients with visual field defects compensate for their deficit by making more frequent eye movements toward the hemianopic field and that visual field enlargements found after vision restoration therapy (VRT) may be an artefact of such eye movements. In order to determine if this was correct, we recorded eye movements in hemianopic subjects before and after VRT. Visual fields were measured in subjects with homonymous visual field defects (n=15) caused by trauma, cerebral ischemia or haemorrhage (lesion age >6 months). Visual field charts were plotted using both high-resolution perimetry (HRP) and conventional perimetry before and after a 3-month period of VRT, with eye movements being recorded with a 2D-eye tracker. This permitted quantification of eye positions and measurements of deviation from fixation. VRT lead to significant visual field enlargements as indicated by an increase of stimulus detection of 3.8% when tested using HRP and about 2.2% (OD) and 3.5% (OS) fewer misses with conventional perimetry. Eye movements were expressed as the standard deviations (S.D.) of the eye position recordings from fixation. Before VRT, the S.D. was +/-0.82 degrees horizontally and +/-1.16 degrees vertically; after VRT, it was +/-0.68 degrees and +/-1.39 degrees , respectively. A cluster analysis of the horizontal eye movements before VRT showed three types of subjects with (i) small (n=7), (ii) medium (n=7) or (iii) large fixation instability (n=1). Saccades were directed equally to the right or the left side; i.e., with no preference toward the blind hemifield. After VRT, many subjects showed a smaller variability of horizontal eye movements. Before VRT, 81.6% of the recorded eye positions were found within a range of 1 degrees horizontally from fixation, whereas after VRT, 88.3% were within that range. In the 2 degrees range, we found 94.8% before and 98.9% after VRT. Subjects moved their eyes 5 degrees or more 0.3% of the time before VRT versus 0.1% after VRT. Thus, in this study, subjects with homonymous visual field defects who were attempting to fixate a central target while their fields were being plotted, typically showed brief horizontal shifts with no preference toward or away from the blind hemifield. These eye movements were usually less than 1 degrees from fixation. Large saccades toward the blind field after VRT were very rare. VRT has no effect on either the direction or the amplitude of horizontal eye movements during visual field testing. These results argue against the theory that the visual field enlargements are artefacts induced by eye movements.

Attention and eye-movement control in reading: The selective reading paradigm.

PubMed

Reingold, Eyal M; Sheridan, Heather; Meadmore, Katie L; Drieghe, Denis; Liversedge, Simon P

2016-12-01

We introduced a novel paradigm for investigating covert attention and eye-movement control in reading. In 2 experiments, participants read sentence words (shown in blue color) while ignoring interleaved distractor strings (shown in orange color). Each single-line text display contained a target word and a critical distractor. Critical distractors were located just prior to the target in the text and were either words or symbol strings (e.g., @#%&). Target word availability for parafoveal processing (i.e., preview validity) was also manipulated. The results indicated much shallower processing of distractors than targets, and this pattern was more pronounced for symbol than word distractors. The influences of word frequency and fixation location on first-pass fixation durations on distractors were dramatically different than the well-documented pattern obtained in normal reading. Robust preview benefits were demonstrated both when the critical distractors were fixated and when the critical distractors were skipped. Finally, with the exception of larger preview benefits that were obtained in the condition in which the target and critical distractor were identical, the magnitude of the preview effect was largely unaffected by the nature of the critical distractor. Implications of the present paradigm and findings to the study of eye-movement control in reading are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A Diagnosis of Insomnia Is Associated With Differential Expression of Sleep-Regulating Genes in Military Personnel.

PubMed

Gill, Jessica M; Lee, Hyunhwa; Baxter, Tristin; Reddy, Swarnalatha Y; Barr, Taura; Kim, Hyung-Suk; Wang, Dan; Mysliwiec, Vincent

2015-07-01

Sleep disturbance is a common and disturbing symptom in military personnel, with many individuals progressing to the development of insomnia, which is characterized by increased arousals, wakefulness after sleep onset, and distorted sleep architecture. The molecular mechanisms underlying insomnia remain elusive, limiting future therapeutic development to address this critical issue. We examined whole gene expression profiles associated with insomnia. We compared subjects with insomnia (n = 25) to controls (n = 13) without insomnia using microarray gene expression profiles obtained from peripheral samples of whole blood obtained from military personnel. Compared to controls, participants with insomnia had differential expression of 44 transcripts from 43 identified genes. Among the identified genes, urotensin 2 was downregulated by more than 6 times in insomnia participants, and the fold-change remained significant after controlling for depression, posttraumatic stress disorder, and medication use. Urotensin 2 is involved in regulation of orexin A and B activity and rapid eye movement during sleep. These findings suggest that differential expression of these sleep-regulating genes contributes to symptoms of insomnia and, specifically, that switching between rapid eye movement and nonrapid eye movement sleep stages underlies insomnia symptoms. Future work to identify therapeutic agents that are able to regulate these pathways may provide novel treatments for insomnia. © The Author(s) 2015.

Eye/Brain/Task Testbed And Software

NASA Technical Reports Server (NTRS)

Janiszewski, Thomas; Mainland, Nora; Roden, Joseph C.; Rothenheber, Edward H.; Ryan, Arthur M.; Stokes, James M.

1994-01-01

Eye/brain/task (EBT) testbed records electroencephalograms, movements of eyes, and structures of tasks to provide comprehensive data on neurophysiological experiments. Intended to serve continuing effort to develop means for interactions between human brain waves and computers. Software library associated with testbed provides capabilities to recall collected data, to process data on movements of eyes, to correlate eye-movement data with electroencephalographic data, and to present data graphically. Cognitive processes investigated in ways not previously possible.

Removing the Interdependency between Horizontal and Vertical Eye-Movement Components in Electrooculograms

PubMed Central

Chang, Won-Du; Cha, Ho-Seung; Im, Chang-Hwan

2016-01-01

This paper introduces a method to remove the unwanted interdependency between vertical and horizontal eye-movement components in electrooculograms (EOGs). EOGs have been widely used to estimate eye movements without a camera in a variety of human-computer interaction (HCI) applications using pairs of electrodes generally attached either above and below the eye (vertical EOG) or to the left and right of the eyes (horizontal EOG). It has been well documented that the vertical EOG component has less stability than the horizontal EOG one, making accurate estimation of the vertical location of the eyes difficult. To address this issue, an experiment was designed in which ten subjects participated. Visual inspection of the recorded EOG signals showed that the vertical EOG component is highly influenced by horizontal eye movements, whereas the horizontal EOG is rarely affected by vertical eye movements. Moreover, the results showed that this interdependency could be effectively removed by introducing an individual constant value. It is therefore expected that the proposed method can enhance the overall performance of practical EOG-based eye-tracking systems. PMID:26907271

A Model of the Spatio-temporal Dynamics of Drosophila Eye Disc Development.

PubMed

Fried, Patrick; Sánchez-Aragón, Máximo; Aguilar-Hidalgo, Daniel; Lehtinen, Birgitta; Casares, Fernando; Iber, Dagmar

2016-09-01

Patterning and growth are linked during early development and have to be tightly controlled to result in a functional tissue or organ. During the development of the Drosophila eye, this linkage is particularly clear: the growth of the eye primordium mainly results from proliferating cells ahead of the morphogenetic furrow (MF), a moving signaling wave that sweeps across the tissue from the posterior to the anterior side, that induces proliferating cells anterior to it to differentiate and become cell cycle quiescent in its wake. Therefore, final eye disc size depends on the proliferation rate of undifferentiated cells and on the speed with which the MF sweeps across the eye disc. We developed a spatio-temporal model of the growing eye disc based on the regulatory interactions controlled by the signals Decapentaplegic (Dpp), Hedgehog (Hh) and the transcription factor Homothorax (Hth) and explored how the signaling patterns affect the movement of the MF and impact on eye disc growth. We used published and new quantitative data to parameterize the model. In particular, two crucial parameter values, the degradation rate of Hth and the diffusion coefficient of Hh, were measured. The model is able to reproduce the linear movement of the MF and the termination of growth of the primordium. We further show that the model can explain several mutant phenotypes, but fails to reproduce the previously observed scaling of the Dpp gradient in the anterior compartment.

The coeruleus/subcoeruleus complex in idiopathic rapid eye movement sleep behaviour disorder.

PubMed

Ehrminger, Mickael; Latimier, Alice; Pyatigorskaya, Nadya; Garcia-Lorenzo, Daniel; Leu-Semenescu, Smaranda; Vidailhet, Marie; Lehericy, Stéphane; Arnulf, Isabelle

2016-04-01

Idiopathic rapid eye movement sleep behaviour disorder is characterized by nocturnal violence, increased muscle tone during rapid eye movement sleep and the lack of any other neurological disease. However, idiopathic rapid eye movement sleep behaviour disorder can precede parkinsonism and dementia by several years. Using 3 T magnetic resonance imaging and neuromelanin-sensitive sequences, we previously found that the signal intensity was reduced in the locus coeruleus/subcoeruleus area of patients with Parkinson's disease and rapid eye movement sleep behaviour disorder. Here, we studied the integrity of the locus coeruleus/subcoeruleus complex with neuromelanin-sensitive imaging in 21 patients with idiopathic rapid eye movement sleep behaviour disorder and compared the results with those from 21 age- and gender-matched healthy volunteers. All subjects underwent a clinical examination, motor, cognitive, autonomous, psychological, olfactory and colour vision tests, and rapid eye movement sleep characterization using video-polysomnography and 3 T magnetic resonance imaging. The patients more frequently had preclinical markers of alpha-synucleinopathies, including constipation, olfactory deficits, orthostatic hypotension, and subtle motor impairment. Using neuromelanin-sensitive imaging, reduced signal intensity was identified in the locus coeruleus/subcoeruleus complex of the patients with idiopathic rapid eye movement sleep behaviour. The mean sensitivity of the visual analyses of the signal performed by neuroradiologists who were blind to the clinical diagnoses was 82.5%, and the specificity was 81% for the identification of idiopathic rapid eye movement sleep behaviour. The results confirm that this complex is affected in idiopathic rapid eye movement sleep behaviour (to the same degree as it is affected in Parkinson's disease). Neuromelanin-sensitive imaging provides an early marker of non-dopaminergic alpha-synucleinopathy that can be detected on an individual basis. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Eye Movements in Risky Choice

PubMed Central

Hermens, Frouke; Matthews, William J.

2015-01-01

Abstract We asked participants to make simple risky choices while we recorded their eye movements. We built a complete statistical model of the eye movements and found very little systematic variation in eye movements over the time course of a choice or across the different choices. The only exceptions were finding more (of the same) eye movements when choice options were similar, and an emerging gaze bias in which people looked more at the gamble they ultimately chose. These findings are inconsistent with prospect theory, the priority heuristic, or decision field theory. However, the eye movements made during a choice have a large relationship with the final choice, and this is mostly independent from the contribution of the actual attribute values in the choice options. That is, eye movements tell us not just about the processing of attribute values but also are independently associated with choice. The pattern is simple—people choose the gamble they look at more often, independently of the actual numbers they see—and this pattern is simpler than predicted by decision field theory, decision by sampling, and the parallel constraint satisfaction model. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd. PMID:27522985

Quantitative analysis on electrooculography (EOG) for neurodegenerative disease

NASA Astrophysics Data System (ADS)

Liu, Chang-Chia; Chaovalitwongse, W. Art; Pardalos, Panos M.; Seref, Onur; Xanthopoulos, Petros; Sackellares, J. C.; Skidmore, Frank M.

2007-11-01

Many studies have documented abnormal horizontal and vertical eye movements in human neurodegenerative disease as well as during altered states of consciousness (including drowsiness and intoxication) in healthy adults. Eye movement measurement may play an important role measuring the progress of neurodegenerative diseases and state of alertness in healthy individuals. There are several techniques for measuring eye movement, Infrared detection technique (IR). Video-oculography (VOG), Scleral eye coil and EOG. Among those available recording techniques, EOG is a major source for monitoring the abnormal eye movement. In this real-time quantitative analysis study, the methods which can capture the characteristic of the eye movement were proposed to accurately categorize the state of neurodegenerative subjects. The EOG recordings were taken while 5 tested subjects were watching a short (>120 s) animation clip. In response to the animated clip the participants executed a number of eye movements, including vertical smooth pursued (SVP), horizontal smooth pursued (HVP) and random saccades (RS). Detection of abnormalities in ocular movement may improve our diagnosis and understanding a neurodegenerative disease and altered states of consciousness. A standard real-time quantitative analysis will improve detection and provide a better understanding of pathology in these disorders.

Eye movements reflect and shape strategies in fraction comparison.

PubMed

Ischebeck, Anja; Weilharter, Marina; Körner, Christof

2016-01-01

The comparison of fractions is a difficult task that can often be facilitated by separately comparing components (numerators and denominators) of the fractions--that is, by applying so-called component-based strategies. The usefulness of such strategies depends on the type of fraction pair to be compared. We investigated the temporal organization and the flexibility of strategy deployment in fraction comparison by evaluating sequences of eye movements in 20 young adults. We found that component-based strategies could account for the response times and the overall number of fixations observed for the different fraction pairs. The analysis of eye movement sequences showed that the initial eye movements in a trial were characterized by stereotypical scanning patterns indicative of an exploratory phase that served to establish the kind of fraction pair presented. Eye movements that followed this phase adapted to the particular type of fraction pair and indicated the deployment of specific comparison strategies. These results demonstrate that participants employ eye movements systematically to support strategy use in fraction comparison. Participants showed a remarkable flexibility to adapt to the most efficient strategy on a trial-by-trial basis. Our results confirm the value of eye movement measurements in the exploration of strategic adaptation in complex tasks.

Gait Balance Disorder by Thalamic Infarction with the Disorder of Interstitial Nucleus of Cajal

PubMed Central

Kurosu, A.; Hayashi, Y.; Wada, K.; Nagaoka, M.

2011-01-01

The interstitial nucleus of Cajal (INC) is thought to play an important role in torsional/vertical eye position and head posture, and disorders of the INC induce abnormal ocular movements and head tilt. Our patients with ocular tilt reactions simultaneously also had disturbances in ambulatory balance, yet no reports address the loss of balance control induced by disorders of the INC. We examined the ambulatory disturbances induced by INC lesion. We experienced three patients with ocular movement disorders and abnormal head tilt due to thalamic infarction. We performed ophthalmic examinations on and checked the balance of them. With funduscopy, abnormal cycloduction was seen in the unaffected side and normal cycloduction was observed in the affected side. Nevertheless, Hess charts showed distortions in the visual image of both eyes. They all had disorders of balance control. We tried to treat them using the Bobath approach for improving their ambulatory balance. With subsequent improvements in balance control it was possible for them to take short walks, but it was difficult to make any improvements in their ocular movement. The INC is related to balance control of ambulation and disorders of the INC induce ambulatory disturbances. Cycloduction was only observed in the unaffected side, but Hess charts showed distortions of the visual image in both eyes. Ambulation was briefly improved, but diplopia persisted in these patients. PMID:21769260

Paroxysmal eye–head movements in Glut1 deficiency syndrome

PubMed Central

Engelstad, Kristin; Kane, Steven A.; Goldberg, Michael E.; De Vivo, Darryl C.

2017-01-01

Objective: To describe a characteristic paroxysmal eye–head movement disorder that occurs in infants with Glut1 deficiency syndrome (Glut1 DS). Methods: We retrospectively reviewed the medical charts of 101 patients with Glut1 DS to obtain clinical data about episodic abnormal eye movements and analyzed video recordings of 18 eye movement episodes from 10 patients. Results: A documented history of paroxysmal abnormal eye movements was found in 32/101 patients (32%), and a detailed description was available in 18 patients, presented here. Episodes started before age 6 months in 15/18 patients (83%), and preceded the onset of seizures in 10/16 patients (63%) who experienced both types of episodes. Eye movement episodes resolved, with or without treatment, by 6 years of age in 7/8 patients with documented long-term course. Episodes were brief (usually <5 minutes). Video analysis revealed that the eye movements were rapid, multidirectional, and often accompanied by a head movement in the same direction. Eye movements were separated by clear intervals of fixation, usually ranging from 200 to 800 ms. The movements were consistent with eye–head gaze saccades. These movements can be distinguished from opsoclonus by the presence of a clear intermovement fixation interval and the association of a same-direction head movement. Conclusions: Paroxysmal eye–head movements, for which we suggest the term aberrant gaze saccades, are an early symptom of Glut1 DS in infancy. Recognition of the episodes will facilitate prompt diagnosis of this treatable neurodevelopmental disorder. PMID:28341645

CEFR and Eye Movement Characteristics during EFL Reading: The Case of Intermediate Readers

ERIC Educational Resources Information Center

Dolgunsöz, Emrah; Sariçoban, Arif

2016-01-01

This study primarily aims to (1) examine the relationship between foreign language reading proficiency and eye movements during reading, and (2) to describe eye movement differences between two CEFR proficiency groups (B1 and B2) by using eye tracking technique. 57 learners of EFL were tested under two experimental conditions: Natural L2 reading…

Vasoactive intestinal polypeptide microinjections into the oral pontine tegmentum enhance rapid eye movement sleep in the rat.

PubMed

Bourgin, P; Lebrand, C; Escourrou, P; Gaultier, C; Franc, B; Hamon, M; Adrien, J

1997-03-01

Rapid eye movement sleep can be elicited in the rat by microinjection of the cholinergic agonist carbachol into the oral pontine reticular nucleus. Intracerebroventricular administration, during the light period, of vasoactive intestinal peptide enhances rapid eye movement sleep in several species. Since this peptide is co-localized with acetylcholine in many neurons in the central nervous system, it was assumed that the oral pontine tegmentum could also be one target for vasoactive intestinal peptide to induce rapid eye movement sleep. This hypothesis was tested by recording the sleep-wakefulness cycle in freely-moving rats injected with vasoactive intestinal peptide or its fragments (1-12 and 10-28) directly into the oral pontine reticular nucleus. when administered into the posterior part of this nucleus, vasoactive intestinal peptide at 1 and 10 ng (in 0.1 microliter of saline), but not its fragments, induced a 2-fold enhancement of rapid eye movement sleep during 4 h, at the expense of wakefulness. At the dose of 10 ng, a significant increase in rapid eye movement sleep persisted for up to 8 h. Moreover, when the peptide was injected into the centre of the positive zone, rapid eye movement sleep was enhanced during three to eight consecutive days. These data provide the first evidence that rapid eye movement sleep can be elicited at both short- and long-term by a single intracerebral microinjection of vasoactive intestinal peptide. Peptidergic mechanisms, possibly in association with cholinergic mechanisms, within the caudal part of the oral pontine reticular nucleus may play a critical role in the long-term regulation of rapid eye movement sleep in rats.

Effects of background stimulation upon eye-movement information.

PubMed

Nakamura, S

1996-04-01

To investigate the effects of background stimulation upon eye-movement information (EMI), the perceived deceleration of the target motion during pursuit eye movement (Aubert-Fleishl paradox) was analyzed. In the experiment, a striped pattern was used as a background stimulus with various brightness contrasts and spatial frequencies for serially manipulating the attributions of the background stimulus. Analysis showed that the retinal-image motion of the background stimulus (optic flow) affected eye-movement information and that the effects of optic flow became stronger when high contrast and low spatial frequency stripes were presented as the background stimulus. In conclusion, optic flow is one source of eye-movement information in determining real object motion, and the effectiveness of optic flow depends on the attributes of the background stimulus.

A Pilot Study of Horizontal Head and Eye Rotations in Baseball Batting.

PubMed

Fogt, Nick; Persson, Tyler W

2017-08-01

The purpose of the study was to measure and compare horizontal head and eye tracking movements as baseball batters "took" pitches and swung at baseball pitches. Two former college baseball players were tested in two conditions. A pitching machine was used to project tennis balls toward the subjects. In the first condition, subjects acted as if they were taking (i.e., not swinging) the pitches. In the second condition, subjects attempted to bat the pitched balls. Head movements were measured with an inertial sensor; eye movements were measured with a video eye tracker. For each condition, the relationship between the horizontal head and eye rotations was similar for the two subjects, as were the overall head-, eye-, and gaze-tracking strategies. In the "take" condition, head movements in the direction of the ball were larger than eye movements for much of the pitch trajectory. Large eye movements occurred only late in the pitch trajectory. Gaze was directed near the ball until approximately 150 milliseconds before the ball arrived at the batter, at which time gaze was directed ahead of the ball to a location near that occupied when the ball crosses the plate. In the "swing" condition, head movements in the direction of the ball were larger than eye movements throughout the pitch trajectory. Gaze was directed near the ball until approximately 50 to 60 milliseconds prior to pitch arrival at the batter. Horizontal head rotations were larger than horizontal eye rotations in both the "take" and "swing" conditions. Gaze was directed ahead of the ball late in the pitch trajectory in the "take" condition, whereas gaze was directed near the ball throughout much of the pitch trajectory in the "swing" condition.

Detecting eye movements in dynamic environments.

PubMed

Reimer, Bryan; Sodhi, Manbir

2006-11-01

To take advantage of the increasing number of in-vehicle devices, automobile drivers must divide their attention between primary (driving) and secondary (operating in-vehicle device) tasks. In dynamic environments such as driving, however, it is not easy to identify and quantify how a driver focuses on the various tasks he/she is simultaneously engaged in, including the distracting tasks. Measures derived from the driver's scan path have been used as correlates of driver attention. This article presents a methodology for analyzing eye positions, which are discrete samples of a subject's scan path, in order to categorize driver eye movements. Previous methods of analyzing eye positions recorded in a dynamic environment have relied completely on the manual identification of the focus of visual attention from a point of regard superimposed on a video of a recorded scene, failing to utilize information regarding movement structure in the raw recorded eye positions. Although effective, these methods are too time consuming to be easily used when the large data sets that would be required to identify subtle differences between drivers, under different road conditions, and with different levels of distraction are processed. The aim of the methods presented in this article are to extend the degree of automation in the processing of eye movement data by proposing a methodology for eye movement analysis that extends automated fixation identification to include smooth and saccadic movements. By identifying eye movements in the recorded eye positions, a method of reducing the analysis of scene video to a finite search space is presented. The implementation of a software tool for the eye movement analysis is described, including an example from an on-road test-driving sample.

Methodological Aspects of Cognitive Rehabilitation with Eye Movement Desensitization and Reprocessing (EMDR)

PubMed Central

Zarghi, Afsaneh; Zali, Alireza; Tehranidost, Mehdi

2013-01-01

A variety of nervous system components such as medulla, pons, midbrain, cerebellum, basal ganglia, parietal, frontal and occipital lobes have role in Eye Movement Desensitization and Reprocessing (EMDR) processes. The eye movement is done simultaneously for attracting client's attention to an external stimulus while concentrating on a certain internal subject. Eye movement guided by therapist is the most common attention stimulus. The role of eye movement has been documented previously in relation with cognitive processing mechanisms. A series of systemic experiments have shown that the eyes’ spontaneous movement is associated with emotional and cognitive changes and results in decreased excitement, flexibility in attention, memory processing, and enhanced semantic recalling. Eye movement also decreases the memory's image clarity and the accompanying excitement. By using EMDR, we can reach some parts of memory which were inaccessible before and also emotionally intolerable. Various researches emphasize on the effectiveness of EMDR in treating and curing phobias, pains, and dependent personality disorders. Consequently, due to the involvement of multiple neural system components, this palliative method of treatment can also help to rehabilitate the neuro-cognitive system. PMID:25337334

Effects of saccadic bilateral eye movements on episodic and semantic autobiographical memory fluency.

PubMed

Parker, Andrew; Parkin, Adam; Dagnall, Neil

2013-01-01

Performing a sequence of fast saccadic horizontal eye movements has been shown to facilitate performance on a range of cognitive tasks, including the retrieval of episodic memories. One explanation for these effects is based on the hypothesis that saccadic eye movements increase hemispheric interaction, and that such interactions are important for particular types of memory. The aim of the current research was to assess the effect of horizontal saccadic eye movements on the retrieval of both episodic autobiographical memory (event/incident based memory) and semantic autobiographical memory (fact based memory) over recent and more distant time periods. It was found that saccadic eye movements facilitated the retrieval of episodic autobiographical memories (over all time periods) but not semantic autobiographical memories. In addition, eye movements did not enhance the retrieval of non-autobiographical semantic memory. This finding illustrates a dissociation between the episodic and semantic characteristics of personal memory and is considered within the context of hemispheric contributions to episodic memory performance.

Effects of Saccadic Bilateral Eye Movements on Episodic and Semantic Autobiographical Memory Fluency

PubMed Central

Parker, Andrew; Parkin, Adam; Dagnall, Neil

2013-01-01

Performing a sequence of fast saccadic horizontal eye movements has been shown to facilitate performance on a range of cognitive tasks, including the retrieval of episodic memories. One explanation for these effects is based on the hypothesis that saccadic eye movements increase hemispheric interaction, and that such interactions are important for particular types of memory. The aim of the current research was to assess the effect of horizontal saccadic eye movements on the retrieval of both episodic autobiographical memory (event/incident based memory) and semantic autobiographical memory (fact based memory) over recent and more distant time periods. It was found that saccadic eye movements facilitated the retrieval of episodic autobiographical memories (over all time periods) but not semantic autobiographical memories. In addition, eye movements did not enhance the retrieval of non-autobiographical semantic memory. This finding illustrates a dissociation between the episodic and semantic characteristics of personal memory and is considered within the context of hemispheric contributions to episodic memory performance. PMID:24133435

The analysis of the influence of fractal structure of stimuli on fractal dynamics in fixational eye movements and EEG signal

NASA Astrophysics Data System (ADS)

Namazi, Hamidreza; Kulish, Vladimir V.; Akrami, Amin

2016-05-01

One of the major challenges in vision research is to analyze the effect of visual stimuli on human vision. However, no relationship has been yet discovered between the structure of the visual stimulus, and the structure of fixational eye movements. This study reveals the plasticity of human fixational eye movements in relation to the ‘complex’ visual stimulus. We demonstrated that the fractal temporal structure of visual dynamics shifts towards the fractal dynamics of the visual stimulus (image). The results showed that images with higher complexity (higher fractality) cause fixational eye movements with lower fractality. Considering the brain, as the main part of nervous system that is engaged in eye movements, we analyzed the governed Electroencephalogram (EEG) signal during fixation. We have found out that there is a coupling between fractality of image, EEG and fixational eye movements. The capability observed in this research can be further investigated and applied for treatment of different vision disorders.

Realization of the ergonomics design and automatic control of the fundus cameras

NASA Astrophysics Data System (ADS)

Zeng, Chi-liang; Xiao, Ze-xin; Deng, Shi-chao; Yu, Xin-ye

2012-12-01

The principles of ergonomics design in fundus cameras should be extending the agreeableness by automatic control. Firstly, a 3D positional numerical control system is designed for positioning the eye pupils of the patients who are doing fundus examinations. This system consists of a electronically controlled chin bracket for moving up and down, a lateral movement of binocular with the detector and the automatic refocusing of the edges of the eye pupils. Secondly, an auto-focusing device for the object plane of patient's fundus is designed, which collects the patient's fundus images automatically whether their eyes is ametropic or not. Finally, a moving visual target is developed for expanding the fields of the fundus images.

Impaired eye movements in presymptomatic spinocerebellar ataxia type 6.

PubMed

Christova, Peka; Anderson, John H; Gomez, Christopher M

2008-04-01

Early detection of impaired neurological function in neurodegenerative diseases may aid in understanding disease pathogenesis and timing of therapeutic trials. To identify early abnormalities of ocular motor function in individuals who have the spinocerebellar ataxia type 6 (SCA6) gene (CACNA1A) but no clinical symptoms. Physiological techniques were used to record and analyze eye movements and postural sway. Four presymptomatic and 5 ataxic patients with SCA6, genetically identified, and 10 healthy controls. Presymptomatic individuals had normal postural sway but definite ocular motor abnormalities. Two had a low-amplitude horizontal gaze-evoked nystagmus, 1 of whom had a significantly decreased eye velocity for upward saccades and an abnormal frequency of square-wave jerks. Another had abnormal square-wave jerks and a fourth had a reduced gain for pursuit tracking. Not all of the presymptomatic patients had the same findings, but a multivariate analysis discriminated the presymptomatic patients, as a group, from healthy controls and the ataxic patients. Among the earliest functional deficits in SCA6 are eye movement abnormalities, including impaired saccade velocity, saccade metrics, and pursuit gain. This suggests that early functional impairments are caused by cellular dysfunction and/or loss in the posterior cerebellar vermis and flocculus. These findings might help to determine the timing of a treatment and to define variables that could be used as outcome measures for the efficacy of therapeutic trials.

Smooth Pursuit Eye Movement Deficits in Patients With Whiplash and Neck Pain are Modulated by Target Predictability.

PubMed

Janssen, Malou; Ischebeck, Britta K; de Vries, Jurryt; Kleinrensink, Gert-Jan; Frens, Maarten A; van der Geest, Jos N

2015-10-01

This is a cross-sectional study. The purpose of this study is to support and extend previous observations on oculomotor disturbances in patients with neck pain and whiplash-associated disorders (WADs) by systematically investigating the effect of static neck torsion on smooth pursuit in response to both predictably and unpredictably moving targets using video-oculography. Previous studies showed that in patients with neck complaints, for instance due to WAD, extreme static neck torsion deteriorates smooth pursuit eye movements in response to predictably moving targets compared with healthy controls. Eye movements in response to a smoothly moving target were recorded with video-oculography in a heterogeneous group of 55 patients with neck pain (including 11 patients with WAD) and 20 healthy controls. Smooth pursuit performance was determined while the trunk was fixed in 7 static rotations relative to the head (from 45° to the left to 45° to right), using both predictably and unpredictably moving stimuli. Patients had reduced smooth pursuit gains and smooth pursuit gain decreased due to neck torsion. Healthy controls showed higher gains for predictably moving targets compared with unpredictably moving targets, whereas patients with neck pain had similar gains in response to both types of target movements. In 11 patients with WAD, increased neck torsion decreased smooth pursuit performance, but only for predictably moving targets. Smooth pursuit of patients with neck pain is affected. The previously reported WAD-specific decline in smooth pursuit due to increased neck torsion seems to be modulated by the predictability of the movement of the target. The observed oculomotor disturbances in patients with WAD are therefore unlikely to be induced by impaired neck proprioception alone. 3.

Is Vestibular Self-Motion Perception Controlled by the Velocity Storage? Insights from Patients with Chronic Degeneration of the Vestibulo-Cerebellum

PubMed Central

Bertolini, Giovanni; Ramat, Stefano; Bockisch, Christopher J.; Marti, Sarah; Straumann, Dominik; Palla, Antonella

2012-01-01

Background The rotational vestibulo-ocular reflex (rVOR) generates compensatory eye movements in response to rotational head accelerations. The velocity-storage mechanism (VSM), which is controlled by the vestibulo-cerebellar nodulus and uvula, determines the rVOR time constant. In healthy subjects, it has been suggested that self-motion perception in response to earth-vertical axis rotations depends on the VSM in a similar way as reflexive eye movements. We aimed at further investigating this hypothesis and speculated that if the rVOR and rotational self-motion perception share a common VSM, alteration in the latter, such as those occurring after a loss of the regulatory control by vestibulo-cerebellar structures, would result in similar reflexive and perceptual response changes. We therefore set out to explore both responses in patients with vestibulo-cerebellar degeneration. Methodology/Principal Findings Reflexive eye movements and perceived rotational velocity were simultaneously recorded in 14 patients with chronic vestibulo-cerebellar degeneration (28–81yrs) and 12 age-matched healthy subjects (30–72yrs) after the sudden deceleration (90°/s2) from constant-velocity (90°/s) rotations about the earth-vertical yaw and pitch axes. rVOR and perceived rotational velocity data were analyzed using a two-exponential model with a direct pathway, representing semicircular canal activity, and an indirect pathway, implementing the VSM. We found that VSM time constants of rVOR and perceived rotational velocity co-varied in cerebellar patients and in healthy controls (Pearson correlation coefficient for yaw 0.95; for pitch 0.93, p<0.01). When constraining model parameters to use the same VSM time constant for rVOR and perceived rotational velocity, moreover, no significant deterioration of the quality of fit was found for both populations (variance-accounted-for >0.8). Conclusions/Significance Our results confirm that self-motion perception in response to rotational velocity-steps may be controlled by the same velocity storage network that controls reflexive eye movements and that no additional, e.g. cortical, mechanisms are required to explain perceptual dynamics. PMID:22719833

Parafoveal magnification: visual acuity does not modulate the perceptual span in reading.

PubMed

Miellet, Sébastien; O'Donnell, Patrick J; Sereno, Sara C

2009-06-01

Models of eye guidance in reading rely on the concept of the perceptual span-the amount of information perceived during a single eye fixation, which is considered to be a consequence of visual and attentional constraints. To directly investigate attentional mechanisms underlying the perceptual span, we implemented a new reading paradigm-parafoveal magnification (PM)-that compensates for how visual acuity drops off as a function of retinal eccentricity. On each fixation and in real time, parafoveal text is magnified to equalize its perceptual impact with that of concurrent foveal text. Experiment 1 demonstrated that PM does not increase the amount of text that is processed, supporting an attentional-based account of eye movements in reading. Experiment 2 explored a contentious issue that differentiates competing models of eye movement control and showed that, even when parafoveal information is enlarged, visual attention in reading is allocated in a serial fashion from word to word.

Effects of phencyclidine, secobarbital and diazepam on eye tracking in rhesus monkeys.

PubMed

Ando, K; Johanson, C E; Levy, D L; Yasillo, N J; Holzman, P S; Schuster, C R

1983-01-01

Rhesus monkeys were trained to track a moving disk using a procedure in which responses on a lever were reinforced with water delivery only when the disk, oscillating in a horizontal plane on a screen at a frequency of 0.4 Hz in a visual angle of 20 degrees, dimmed for a brief period. Pursuit eye movements were recorded by electrooculography (EOG). IM phencyclidine, secobarbital, and diazepam injections decreased the number of reinforced lever presses in a dose-related manner. Both secobarbital and diazepam produced episodic jerky-pursuit eye movements, while phencyclidine had no consistent effects on eye movements. Lever pressing was disrupted at doses which had little effect on the quality of smooth-pursuit eye movements in some monkeys. This separation was particularly pronounced with diazepam. The similarities of the drug effects on smooth-pursuit eye movements between the present study and human studies indicate that the present method using rhesus monkeys may be useful for predicting drug effects on eye tracking and oculomotor function in humans.

Eye-Pursuit and Reafferent Head Movement Signals Carried by Pursuit Neurons in the Caudal Part of the Frontal Eye Fields during Head-Free Pursuit

PubMed Central

Kasahara, Satoshi; Akao, Teppei; Kurkin, Sergei; Peterson, Barry W.

2009-01-01

Eye and head movements are coordinated during head-free pursuit. To examine whether pursuit neurons in frontal eye fields (FEF) carry gaze-pursuit commands that drive both eye-pursuit and head-pursuit, monkeys whose heads were free to rotate about a vertical axis were trained to pursue a juice feeder with their head and a target with their eyes. Initially the feeder and target moved synchronously with the same visual angle. FEF neurons responding to this gaze-pursuit were tested for eye-pursuit of target motion while the feeder was stationary and for head-pursuit while the target was stationary. The majority of pursuit neurons exhibited modulation during head-pursuit, but their preferred directions during eye-pursuit and head-pursuit were different. Although peak modulation occurred during head movements, the onset of discharge usually was not aligned with the head movement onset. The minority of neurons whose discharge onset was so aligned discharged after the head movement onset. These results do not support the idea that the head-pursuit–related modulation reflects head-pursuit commands. Furthermore, modulation similar to that during head-pursuit was obtained by passive head rotation on stationary trunk. Our results suggest that FEF pursuit neurons issue gaze or eye movement commands during gaze-pursuit and that the head-pursuit–related modulation primarily reflects reafferent signals resulting from head movements. PMID:18483002

The brain stem saccadic burst generator encodes gaze in three-dimensional space.

PubMed

Van Horn, Marion R; Sylvestre, Pierre A; Cullen, Kathleen E

2008-05-01

When we look between objects located at different depths the horizontal movement of each eye is different from that of the other, yet temporally synchronized. Traditionally, a vergence-specific neuronal subsystem, independent from other oculomotor subsystems, has been thought to generate all eye movements in depth. However, recent studies have challenged this view by unmasking interactions between vergence and saccadic eye movements during disconjugate saccades. Here, we combined experimental and modeling approaches to address whether the premotor command to generate disconjugate saccades originates exclusively in "vergence centers." We found that the brain stem burst generator, which is commonly assumed to drive only the conjugate component of eye movements, carries substantial vergence-related information during disconjugate saccades. Notably, facilitated vergence velocities during disconjugate saccades were synchronized with the burst onset of excitatory and inhibitory brain stem saccadic burst neurons (SBNs). Furthermore, the time-varying discharge properties of the majority of SBNs (>70%) preferentially encoded the dynamics of an individual eye during disconjugate saccades. When these experimental results were implemented into a computer-based simulation, to further evaluate the contribution of the saccadic burst generator in generating disconjugate saccades, we found that it carries all the vergence drive that is necessary to shape the activity of the abducens motoneurons to which it projects. Taken together, our results provide evidence that the premotor commands from the brain stem saccadic circuitry, to the target motoneurons, are sufficient to ensure the accurate control shifts of gaze in three dimensions.

Advances in Relating Eye Movements and Cognition

ERIC Educational Resources Information Center

Hayhoe, Mary M.

2004-01-01

Measurement of eye movements is a powerful tool for investigating perceptual and cognitive function in both infants and adults. Straightforwardly, eye movements provide a multifaceted measure of performance. For example, the location of fixations, their duration, time of occurrence, and accuracy all are potentially revealing and often allow…

Generating and Describing Affective Eye Behaviors

NASA Astrophysics Data System (ADS)

Mao, Xia; Li, Zheng

The manner of a person's eye movement conveys much about nonverbal information and emotional intent beyond speech. This paper describes work on expressing emotion through eye behaviors in virtual agents based on the parameters selected from the AU-Coded facial expression database and real-time eye movement data (pupil size, blink rate and saccade). A rule-based approach to generate primary (joyful, sad, angry, afraid, disgusted and surprise) and intermediate emotions (emotions that can be represented as the mixture of two primary emotions) utilized the MPEG4 FAPs (facial animation parameters) is introduced. Meanwhile, based on our research, a scripting tool, named EEMML (Emotional Eye Movement Markup Language) that enables authors to describe and generate emotional eye movement of virtual agents, is proposed.

Eye movements during spoken word recognition in Russian children.

PubMed

Sekerina, Irina A; Brooks, Patricia J

2007-09-01

This study explores incremental processing in spoken word recognition in Russian 5- and 6-year-olds and adults using free-viewing eye-tracking. Participants viewed scenes containing pictures of four familiar objects and clicked on a target embedded in a spoken instruction. In the cohort condition, two object names shared identical three-phoneme onsets. In the noncohort condition, all object names had unique onsets. Coarse-grain analyses of eye movements indicated that adults produced looks to the competitor on significantly more cohort trials than on noncohort trials, whereas children surprisingly failed to demonstrate cohort competition due to widespread exploratory eye movements across conditions. Fine-grain analyses, in contrast, showed a similar time course of eye movements across children and adults, but with cohort competition lingering more than 1s longer in children. The dissociation between coarse-grain and fine-grain eye movements indicates a need to consider multiple behavioral measures in making developmental comparisons in language processing.

Eye Movements in Darkness Modulate Self-Motion Perception.

PubMed

Clemens, Ivar Adrianus H; Selen, Luc P J; Pomante, Antonella; MacNeilage, Paul R; Medendorp, W Pieter

2017-01-01

During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first ( n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment ( n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation.

Eye Movements in Darkness Modulate Self-Motion Perception

PubMed Central

Pomante, Antonella

2017-01-01

Abstract During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first (n = 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment (n = 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation. PMID:28144623

Association between vestibulo-ocular reflex suppression, balance, gait, and fall risk in ageing and neurodegenerative disease: protocol of a one-year prospective follow-up study.

PubMed

Srulijes, Karin; Mack, David J; Klenk, Jochen; Schwickert, Lars; Ihlen, Espen A F; Schwenk, Michael; Lindemann, Ulrich; Meyer, Miriam; Srijana, K C; Hobert, Markus A; Brockmann, Kathrin; Wurster, Isabel; Pomper, Jörn K; Synofzik, Matthis; Schneider, Erich; Ilg, Uwe; Berg, Daniela; Maetzler, Walter; Becker, Clemens

2015-10-09

Falls frequency increases with age and particularly in neurogeriatric cohorts. The interplay between eye movements and locomotion may contribute substantially to the occurrence of falls, but is hardly investigated. This paper provides an overview of current approaches to simultaneously measure eye and body movements, particularly for analyzing the association of vestibulo-ocular reflex (VOR) suppression, postural deficits and falls in neurogeriatric risk cohorts. Moreover, VOR suppression is measured during head-fixed target presentation and during gaze shifting while postural control is challenged. Using these approaches, we aim at identifying quantitative parameters of eye-head-coordination during postural balance and gait, as indicators of fall risk. Patients with Progressive Supranuclear Palsy (PSP) or Parkinson's disease (PD), age- and sex-matched healthy older adults, and a cohort of young healthy adults will be recruited. Baseline assessment will include a detailed clinical assessment, covering medical history, neurological examination, disease specific clinical rating scales, falls-related self-efficacy, activities of daily living, neuro-psychological screening, assessment of mobility function and a questionnaire for retrospective falls. Moreover, participants will simultaneously perform eye and head movements (fixating a head-fixed target vs. shifting gaze to light emitting diodes in order to quantify vestibulo-ocular reflex suppression ability) under different conditions (sitting, standing, or walking). An eye/head tracker synchronized with a 3-D motion analysis system will be used to quantify parameters related to eye-head-coordination, postural balance, and gait. Established outcome parameters related to VOR suppression ability (e.g., gain, saccadic reaction time, frequency of saccades) and motor related fall risk (e.g., step-time variability, postural sway) will be calculated. Falls will be assessed prospectively over 12 months via protocols and monthly telephone interviews. This study protocol describes an experimental setup allowing the analysis of simultaneously assessed eye, head and body movements. Results will improve our understanding of the influence of the interplay between eye, head and body movements on falls in geriatric high-risk cohorts.

Hawk Eyes I: Diurnal Raptors Differ in Visual Fields and Degree of Eye Movement

PubMed Central

O'Rourke, Colleen T.; Hall, Margaret I.; Pitlik, Todd; Fernández-Juricic, Esteban

2010-01-01

Background Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. Methodology/Principal Findings We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. Conclusions We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while perching. PMID:20877645

Hawk eyes I: diurnal raptors differ in visual fields and degree of eye movement.

PubMed

O'Rourke, Colleen T; Hall, Margaret I; Pitlik, Todd; Fernández-Juricic, Esteban

2010-09-22

Different strategies to search and detect prey may place specific demands on sensory modalities. We studied visual field configuration, degree of eye movement, and orbit orientation in three diurnal raptors belonging to the Accipitridae and Falconidae families. We used an ophthalmoscopic reflex technique and an integrated 3D digitizer system. We found inter-specific variation in visual field configuration and degree of eye movement, but not in orbit orientation. Red-tailed Hawks have relatively small binocular areas (∼33°) and wide blind areas (∼82°), but intermediate degree of eye movement (∼5°), which underscores the importance of lateral vision rather than binocular vision to scan for distant prey in open areas. Cooper's Hawks' have relatively wide binocular fields (∼36°), small blind areas (∼60°), and high degree of eye movement (∼8°), which may increase visual coverage and enhance prey detection in closed habitats. Additionally, we found that Cooper's Hawks can visually inspect the items held in the tip of the bill, which may facilitate food handling. American Kestrels have intermediate-sized binocular and lateral areas that may be used in prey detection at different distances through stereopsis and motion parallax; whereas the low degree eye movement (∼1°) may help stabilize the image when hovering above prey before an attack. We conclude that: (a) there are between-species differences in visual field configuration in these diurnal raptors; (b) these differences are consistent with prey searching strategies and degree of visual obstruction in the environment (e.g., open and closed habitats); (c) variations in the degree of eye movement between species appear associated with foraging strategies; and (d) the size of the binocular and blind areas in hawks can vary substantially due to eye movements. Inter-specific variation in visual fields and eye movements can influence behavioral strategies to visually search for and track prey while perching.

Moving the eye of the beholder. Motor components in vision determine aesthetic preference.

PubMed

Topolinski, Sascha

2010-09-01

Perception entails not only sensory input (e.g., merely seeing), but also subsidiary motor processes (e.g., moving the eyes); such processes have been neglected in research on aesthetic preferences. To fill this gap, the present research manipulated the fluency of perceptual motor processes independently from sensory input and predicted that this increased fluency would result in increased aesthetic preference for stimulus movements that elicited the same motor movements as had been previously trained. Specifically, addressing the muscles that move the eyes, I trained participants to follow a stimulus movement without actually seeing it. Experiment 1 demonstrated that ocular-muscle training resulted in the predicted increase in preference for trained stimulus movements compared with untrained stimulus movements, although participants had not previously seen any of the movements. Experiments 2 and 3 showed that actual motor matching and not perceptual similarity drove this effect. Thus, beauty may be not only in the eye of the beholder, but also in the eyes' movements.

Short-latency primate vestibuloocular responses during translation

NASA Technical Reports Server (NTRS)

Angelaki, D. E.; McHenry, M. Q.

1999-01-01

Short-lasting, transient head displacements and near target fixation were used to measure the latency and early response gain of vestibularly evoked eye movements during lateral and fore-aft translations in rhesus monkeys. The latency of the horizontal eye movements elicited during lateral motion was 11.9 +/- 5.4 ms. Viewing distance-dependent behavior was seen as early as the beginning of the response profile. For fore-aft motion, latencies were different for forward and backward displacements. Latency averaged 7.1 +/- 9.3 ms during forward motion (same for both eyes) and 12.5 +/- 6.3 ms for the adducting eye (e.g., left eye during right fixation) during backward motion. Latencies during backward motion were significantly longer for the abducting eye (18.9 +/- 9.8 ms). Initial acceleration gains of the two eyes were generally larger than unity but asymmetric. Specifically, gains were consistently larger for abducting than adducting eye movements. The large initial acceleration gains tended to compensate for the response latencies such that the early eye movement response approached, albeit consistently incompletely, that required for maintaining visual acuity during the movement. These short-latency vestibuloocular responses could complement the visually generated optic flow responses that have been shown to exhibit much longer latencies.

One-Step "Change" and "Compare" Word Problems: Focusing on Eye-Movements

ERIC Educational Resources Information Center

Moutsios-Rentzos, Andreas; Stamatis, Panagiotis J.

2015-01-01

Introduction. In this study, we focus on the relationship between the students' mathematical thinking and their non-mechanically identified eye-movements with the purpose to gain deeper understanding about the students' reasoning processes and to investigate the feasibility of incorporating eye-movement information in everyday pedagogy. Method.…

Dissociable Stages of Problem Solving (I): Temporal Characteristics Revealed by Eye-Movement Analyses

ERIC Educational Resources Information Center

Nitschke, Kai; Ruh, Nina; Kappler, Sonja; Stahl, Christoph; Kaller, Christoph P.

2012-01-01

Understanding the functional neuroanatomy of planning and problem solving may substantially benefit from better insight into the chronology of the cognitive processes involved. Based on the assumption that regularities in cognitive processing are reflected in overtly observable eye-movement patterns, here we recorded eye movements while…

Horizontal Saccadic Eye Movements Enhance the Retrieval of Landmark Shape and Location Information

ERIC Educational Resources Information Center

Brunye, Tad T.; Mahoney, Caroline R.; Augustyn, Jason S.; Taylor, Holly A.

2009-01-01

Recent work has demonstrated that horizontal saccadic eye movements enhance verbal episodic memory retrieval, particularly in strongly right-handed individuals. The present experiments test three primary assumptions derived from this research. First, horizontal eye movements should facilitate episodic memory for both verbal and non-verbal…

Eye Movement as an Indicator of Sensory Components in Thought.

ERIC Educational Resources Information Center

Buckner, Michael; And Others

1987-01-01

Investigated Neuro-Linguistic Programming eye movement model's claim that specific eye movements are indicative of specific sensory components in thought. Agreement between students' (N=48) self-reports and trained observers' records support visual and auditory portions of model; do not support kinesthetic portion. Interrater agreement supports…

Adaptation to vestibular disorientation. III, Influence on adaptation of interrupting nystagmic eye movements with opposing stimuli.

DOT National Transportation Integrated Search

1966-09-01

Failure of adaptation of nystagmic eye movements to occur under certain conditions of stimulation by angular acceleration has been ascribed to a failure to allow the eye-movement response to run its course. In this study, 3 groups of subjects were te...

Eye movements reflect and shape strategies in fraction comparison

PubMed Central

Ischebeck, Anja; Weilharter, Marina; Körner, Christof

2016-01-01

The comparison of fractions is a difficult task that can often be facilitated by separately comparing components (numerators and denominators) of the fractions—that is, by applying so-called component-based strategies. The usefulness of such strategies depends on the type of fraction pair to be compared. We investigated the temporal organization and the flexibility of strategy deployment in fraction comparison by evaluating sequences of eye movements in 20 young adults. We found that component-based strategies could account for the response times and the overall number of fixations observed for the different fraction pairs. The analysis of eye movement sequences showed that the initial eye movements in a trial were characterized by stereotypical scanning patterns indicative of an exploratory phase that served to establish the kind of fraction pair presented. Eye movements that followed this phase adapted to the particular type of fraction pair and indicated the deployment of specific comparison strategies. These results demonstrate that participants employ eye movements systematically to support strategy use in fraction comparison. Participants showed a remarkable flexibility to adapt to the most efficient strategy on a trial-by-trial basis. Our results confirm the value of eye movement measurements in the exploration of strategic adaptation in complex tasks. PMID:26039819

Eye Movement Abnormalities in Joubert Syndrome

PubMed Central

Weiss, Avery H.; Doherty, Dan; Parisi, Melissa; Shaw, Dennis; Glass, Ian; Phillips, James O.

2011-01-01

Purpose Joubert syndrome is a genetic disorder characterized by hypoplasia of the midline cerebellum and deficiency of crossed connections between neural structures in the brain stem that control eye movements. The goal of the study was to quantify the eye movement abnormalities that occur in Joubert syndrome. Methods Eye movements were recorded in response to stationary stimuli and stimuli designed to elicit smooth pursuit, saccades, optokinetic nystagmus (OKN), vestibulo-ocular reflex (VOR), and vergence using video-oculography or Skalar search coils in 8 patients with Joubert syndrome. All patients underwent high-resolution magnetic resonance imaging (MRI). Results All patients had the highly characteristic molar tooth sign on brain MRI. Six patients had conjugate pendular (n = 4) or see-saw nystagmus (n = 2); gaze holding was stable in four patients. Smooth-pursuit gains were 0.28 to 1.19, 0.11 to 0.68, and 0.33 to 0.73 at peak stimulus velocities of 10, 20, and 30 deg/s in six patients; smooth pursuit could not be elicited in four patients. Saccade gains in five patients ranged from 0.35 to 0.91 and velocities ranged from 60.9 to 259.5 deg/s. Targeted saccades could not be elicited in five patients. Horizontal OKN gain was uniformly reduced across gratings drifted at velocities of 15, 30, and 45 deg/s. VOR gain was 0.8 or higher and phase appropriate in three of seven subjects; VOR gain was 0.3 or less and phase was indeterminate in four subjects. Conclusions The abnormalities in gaze-holding and eye movements are consistent with the distributed abnormalities of midline cerebellum and brain stem regions associated with Joubert syndrome. PMID:19443711

Competition between color and luminance for target selection in smooth pursuit and saccadic eye movements.

PubMed

Spering, Miriam; Montagnini, Anna; Gegenfurtner, Karl R

2008-11-24

Visual processing of color and luminance for smooth pursuit and saccadic eye movements was investigated using a target selection paradigm. In two experiments, stimuli were varied along the dimensions color and luminance, and selection of the more salient target was compared in pursuit and saccades. Initial pursuit was biased in the direction of the luminance component whereas saccades showed a relative preference for color. An early pursuit response toward luminance was often reversed to color by a later saccade. Observers' perceptual judgments of stimulus salience, obtained in two control experiments, were clearly biased toward luminance. This choice bias in perceptual data implies that the initial short-latency pursuit response agrees with perceptual judgments. In contrast, saccades, which have a longer latency than pursuit, do not seem to follow the perceptual judgment of salience but instead show a stronger relative preference for color. These substantial differences in target selection imply that target selection processes for pursuit and saccadic eye movements use distinctly different weights for color and luminance stimuli.

Oculomotor Evidence for Top-Down Control following the Initial Saccade

PubMed Central

Siebold, Alisha; van Zoest, Wieske; Donk, Mieke

2011-01-01

The goal of the current study was to investigate how salience-driven and goal-driven processes unfold during visual search over multiple eye movements. Eye movements were recorded while observers searched for a target, which was located on (Experiment 1) or defined as (Experiment 2) a specific orientation singleton. This singleton could either be the most, medium, or least salient element in the display. Results were analyzed as a function of response time separately for initial and second eye movements. Irrespective of the search task, initial saccades elicited shortly after the onset of the search display were primarily salience-driven whereas initial saccades elicited after approximately 250 ms were completely unaffected by salience. Initial saccades were increasingly guided in line with task requirements with increasing response times. Second saccades were completely unaffected by salience and were consistently goal-driven, irrespective of response time. These results suggest that stimulus-salience affects the visual system only briefly after a visual image enters the brain and has no effect thereafter. PMID:21931603

Saccade preparation is required for exogenous attention but not endogenous attention or IOR.

PubMed

Smith, Daniel T; Schenk, Thomas; Rorden, Chris

2012-12-01

Covert attention is tightly coupled with the control of eye movements, but there is controversy about how tight this coupling is. The premotor theory of attention proposes that activation of the eye movement system is necessary to produce shifts of attention. In this study, we experimentally prevented healthy participants from planning or executing eye movements and observed the effect on exogenous attention, inhibition of return (IOR), and endogenous attention. The participants experienced a deficit of exogenous attentional facilitation that was specific to locations that were inaccessible by saccade. In contrast, their ability to endogenously orient attention was preserved, as was IOR. These results show that (a) exogenous attention depends on motor preparation, (b) IOR is independent of motor preparation and exogenous attention, and (c) endogenous attention is independent of motor preparation. Although these data are consistent with a weak version of the premotor theory, we believe they can be better explained by a biased competition account of visual attention.

On the Visual Input Driving Human Smooth-Pursuit Eye Movements

NASA Technical Reports Server (NTRS)

Stone, Leland S.; Beutter, Brent R.; Lorenceau, Jean

1996-01-01

Current computational models of smooth-pursuit eye movements assume that the primary visual input is local retinal-image motion (often referred to as retinal slip). However, we show that humans can pursue object motion with considerable accuracy, even in the presence of conflicting local image motion. This finding indicates that the visual cortical area(s) controlling pursuit must be able to perform a spatio-temporal integration of local image motion into a signal related to object motion. We also provide evidence that the object-motion signal that drives pursuit is related to the signal that supports perception. We conclude that current models of pursuit should be modified to include a visual input that encodes perceived object motion and not merely retinal image motion. Finally, our findings suggest that the measurement of eye movements can be used to monitor visual perception, with particular value in applied settings as this non-intrusive approach would not require interrupting ongoing work or training.

Three-dimensional organization of vestibular-related eye movements to off-vertical axis rotation and linear translation in pigeons

NASA Technical Reports Server (NTRS)

Dickman, J. D.; Angelaki, D. E.

1999-01-01

During linear accelerations, compensatory reflexes should continually occur in order to maintain objects of visual interest as stable images on the retina. In the present study, the three-dimensional organization of the vestibulo-ocular reflex in pigeons was quantitatively examined during linear accelerations produced by constant velocity off-vertical axis yaw rotations and translational motion in darkness. With off-vertical axis rotations, sinusoidally modulated eye-position and velocity responses were observed in all three components, with the vertical and torsional eye movements predominating the response. Peak torsional and vertical eye positions occurred when the head was oriented with the lateral visual axis of the right eye directed orthogonal to or aligned with the gravity vector, respectively. No steady-state horizontal nystagmus was obtained with any of the rotational velocities (8-58 degrees /s) tested. During translational motion, delivered along or perpendicular to the lateral visual axis, vertical and torsional eye movements were elicited. No significant horizontal eye movements were observed during lateral translation at frequencies up to 3 Hz. These responses suggest that, in pigeons, all linear accelerations generate eye movements that are compensatory to the direction of actual or perceived tilt of the head relative to gravity. In contrast, no translational horizontal eye movements, which are known to be compensatory to lateral translational motion in primates, were observed under the present experimental conditions.

New methods for the assessment of accommodative convergence.

PubMed

Asakawa, Ken; Ishikawa, Hitoshi; Shoji, Nobuyuki

2009-01-01

The authors introduced a new objective method for measuring horizontal eye movements based on the first Purkinje image with the use of infrared charge-coupled device (CCD) cameras and compared stimulus accommodative convergence to accommodation (AC/A) ratios as determined by a standard gradient method. The study included 20 patients, 5 to 9 years old, who had intermittent exotropia (10 eyes) and accommodative esotropia (10 eyes). Measurement of horizontal eye movements in millimeters (mm), based on the first Purkinje image, was obtained with a TriIRIS C9000 instrument (Hamamatsu Photonics K.K., Hamamatsu, Japan). The stimulus AC/A ratio was determined with the far gradient method. The average values of horizontal eye movements (mm) and eye deviation (Delta) (a) before and (b) after an accommodative stimulus of 3.00 diopters (D) were calculated with the following formula: horizontal eye movements (mm/D) and stimulus AC/A ratio (Delta/D) = (b - a)/3. The average values of the horizontal eye movements and the stimulus AC/A ratio were 0.5 mm/D and 3.8 Delta/D, respectively. Correlation analysis showed a strong positive correlation between these two parameters (r = 0.92). Moreover, horizontal eye movements are directly proportional to the AC/A ratio measured with the gradient method. The methods used in this study allow objective recordings of accommodative convergence to be obtained in many clinical situations. Copyright 2009, SLACK Incorporated.

Exploring the Lack of a Disfluency Effect: Evidence from Eye Movements

ERIC Educational Resources Information Center

Strukelj, Alexander; Scheiter, Katharina; Nyström, Marcus; Holmqvist, Kenneth

2016-01-01

An eye-tracking study with 60 native Swedish speakers (18-30 years) was conducted to investigate the positive effects on learning outcomes predicted by the disfluency effect. Subtle low-pass filtering was used as a disfluency manipulation and compared with a control condition using regular text. The text was presented on four separate text…

An ocular biomechanic model for dynamic simulation of different eye movements.

PubMed

Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

2018-04-11

Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Eye-hand coupling during closed-loop drawing: evidence of shared motor planning?

PubMed

Reina, G Anthony; Schwartz, Andrew B

2003-04-01

Previous paradigms have used reaching movements to study coupling of eye-hand kinematics. In the present study, we investigated eye-hand kinematics as curved trajectories were drawn at normal speeds. Eye and hand movements were tracked as a monkey traced ellipses and circles with the hand in free space while viewing the hand's position on a computer monitor. The results demonstrate that the movement of the hand was smooth and obeyed the 2/3 power law. Eye position, however, was restricted to 2-3 clusters along the hand's trajectory and fixed approximately 80% of the time in one of these clusters. The eye remained stationary as the hand moved away from the fixation for up to 200 ms and saccaded ahead of the hand position to the next fixation along the trajectory. The movement from one fixation cluster to another consistently occurred just after the tangential hand velocity had reached a local minimum, but before the next segment of the hand's trajectory began. The next fixation point was close to an area of high curvature along the hand's trajectory even though the hand had not reached that point along the path. A visuo-motor illusion of hand movement demonstrated that the eye movement was influenced by hand movement and not simply by visual input. During the task, neural activity of pre-motor cortex (area F4) was recorded using extracellular electrodes and used to construct a population vector of the hand's trajectory. The results suggest that the saccade onset is correlated in time with maximum curvature in the population vector trajectory for the hand movement. We hypothesize that eye and arm movements may have common, or shared, information in forming their motor plans.

Novel method for evaluation of eye movements in patients with narcolepsy.

PubMed

Christensen, Julie A E; Kempfner, Lykke; Leonthin, Helle L; Hvidtfelt, Mathias; Nikolic, Miki; Kornum, Birgitte Rahbek; Jennum, Poul

2017-05-01

Narcolepsy causes abnormalities in the control of wake-sleep, non-rapid-eye-movement (non-REM) sleep and REM sleep, which includes specific eye movements (EMs). In this study, we aim to evaluate EM characteristics in narcolepsy as compared to controls using an automated detector. We developed a data-driven method to detect EMs during sleep based on two EOG signals recorded as part of a polysomnography (PSG). The method was optimized using the manually scored hypnograms from 36 control subjects. The detector was applied on a clinical sample with subjects suspected for central hypersomnias. Based on PSG, multiple sleep latency test and cerebrospinal fluid hypocretin-1 measures, they were divided into clinical controls (N = 20), narcolepsy type 2 (NT2, N = 19), and narcolepsy type 1 (NT1, N = 28). We investigated the distribution of EMs across sleep stages and cycles. NT1 patients had significantly less EMs during wake, N1, and N2 sleep and more EMs during REM sleep compared to clinical controls, and significantly less EMs during wake and N1 sleep compared to NT2 patients. Furthermore, NT1 patients showed less EMs during NREM sleep in the first sleep cycle and more EMs during NREM sleep in the second sleep cycle compared to clinical controls and NT2 patients. NT1 patients show an altered distribution of EMs across sleep stages and cycles compared to NT2 patients and clinical controls, suggesting that EMs are directly or indirectly controlled by the hypocretinergic system. A data-driven EM detector may contribute to the evaluation of narcolepsy and other disorders involving the control of EMs. Copyright © 2016 Elsevier B.V. All rights reserved.

Roles of the Declive, Folium, and Tuber Cerebellar Vermian Lobules in Sportspeople

PubMed Central

Park, In Sung; Lee, Nam Joon

2018-01-01

The cerebellum plays vital roles in balance control and motor learning, including in saccadic adaptation and coordination. It consists of the vermis and two hemispheres and is anatomically separated into ten lobules that are designated as I–X. Although neuroimaging and clinical studies suggest that functions are compartmentalized within the cerebellum, the function of each cerebellar lobule is not fully understood. Electrophysiological and lesion studies in animals as well as neuroimaging and lesion studies in humans have revealed that vermian lobules VI and VII (declive, folium, and tuber) are critical for controlling postural balance, saccadic eye movements, and coordination. In addition, recent structural magnetic resonance imaging studies have revealed that these lobules are larger in elite basketball and short-track speed skaters. Furthermore, in female short-track speed skaters, the volume of this region is significantly correlated with static balance. This article reviews the function of vermian lobules VI and VII, focusing on the control of balance, eye movements, and coordination including coordination between the eyes and hands and bimanual coordination. PMID:29141275

Why Do We Move Our Head to Look at an Object in Our Peripheral Region? Lateral Viewing Interferes with Attentive Search

PubMed Central

Nakashima, Ryoichi; Shioiri, Satoshi

2014-01-01

Why do we frequently fixate an object of interest presented peripherally by moving our head as well as our eyes, even when we are capable of fixating the object with an eye movement alone (lateral viewing)? Studies of eye-head coordination for gaze shifts have suggested that the degree of eye-head coupling could be determined by an unconscious weighing of the motor costs and benefits of executing a head movement. The present study investigated visual perceptual effects of head direction as an additional factor impacting on a cost-benefit organization of eye-head control. Three experiments using visual search tasks were conducted, manipulating eye direction relative to head orientation (front or lateral viewing). Results show that lateral viewing increased the time required to detect a target in a search for the letter T among letter L distractors, a serial attentive search task, but not in a search for T among letter O distractors, a parallel preattentive search task (Experiment 1). The interference could not be attributed to either a deleterious effect of lateral gaze on the accuracy of saccadic eye movements, nor to potentially problematic optical effects of binocular lateral viewing, because effect of head directions was obtained under conditions in which the task was accomplished without saccades (Experiment 2), and during monocular viewing (Experiment 3). These results suggest that a difference between the head and eye directions interferes with visual processing, and that the interference can be explained by the modulation of attention by the relative positions of the eyes and head (or head direction). PMID:24647634

Association between reading speed, cycloplegic refractive error, and oculomotor function in reading disabled children versus controls.

PubMed

Quaid, Patrick; Simpson, Trefford

2013-01-01

Approximately one in ten students aged 6 to 16 in Ontario (Canada) school boards have an individual education plan (IEP) in place due to various learning disabilities, many of which are specific to reading difficulties. The relationship between reading (specifically objectively determined reading speed and eye movement data), refractive error, and binocular vision related clinical measurements remain elusive. One hundred patients were examined in this study (50 IEP and 50 controls, age range 6 to 16 years). IEP patients were referred by three local school boards, with controls being recruited from the routine clinic population (non-IEP patients in the same age group). A comprehensive eye examination was performed on all subjects, in addition to a full binocular vision work-up and cycloplegic refraction. In addition to the cycloplegic refractive error, the following binocular vision related data was also acquired: vergence facility, vergence amplitudes, accommodative facility, accommodative amplitudes, near point of convergence, stereopsis, and a standardized symptom scoring scale. Both the IEP and control groups were also examined using the Visagraph III system, which permits recording of the following reading parameters objectively: (i) reading speed, both raw values and values compared to grade normative data, and (ii) the number of eye movements made per 100 words read. Comprehension was assessed via a questionnaire administered at the end of the reading task, with each subject requiring 80% or greater comprehension. The IEP group had significantly greater hyperopia compared to the control group on cycloplegic examination. Vergence facility was significantly correlated to (i) reading speed, (ii) number of eye movements made when reading, and (iii) a standardized symptom scoring system. Vergence facility was also significantly reduced in the IEP group versus controls. Significant differences in several other binocular vision related scores were also found. This research indicates there are significant associations between reading speed, refractive error, and in particular vergence facility. It appears sensible that students being considered for reading specific IEP status should have a full eye examination (including cycloplegia), in addition to a comprehensive binocular vision evaluation.

Is adaptation to perceived interocular differences in height explained by vertical fusional eye movements?

PubMed

Maier, Felix M; Schaeffel, Frank

2013-07-24

To find out whether adaptation to a vertical prism involves more than fusional vertical eye movements. Adaptation to a vertical base-up 3 prism diopter prism was measured in a custom-programmed Maddox test in nine visually normal emmetropic subjects (mean age 27.0 ± 2.8 years). Vertical eye movements were binocularly measured in six of the subjects with a custom-programmed binocular video eye tracker. In the Maddox test, some subjects adjusted the perceived height as expected from the power of the prism while others appeared to ignore the prism. After 15 minutes of adaptation, the interocular difference in perceived height was reduced by on average 51% (from 0.86°-0.44°). The larger the initially perceived difference in height in a subject, the larger the amplitude of adaptation was. Eye tracking showed that the prism generated divergent vertical eye movements of 1.2° on average, which was less than expected from its power. Differences in eye elevation were maintained as long as the prism was in place. Small angles of lateral head tilt generated large interocular differences in eye elevation, much larger than the effects introduced by the prism. Vertical differences in retinal image height were compensated by vertical fusional eye movements but some subjects responded poorly to a vertical prism in both experiments; fusional eye movements were generally too small to realign both foveae with the fixation target; and the prism adaptation in the Maddox test was fully explained by the changes in vertical eye position, suggesting that no further adaptational mechanism may be involved.

Ocular stability and set-point adaptation

PubMed Central

Jareonsettasin, P.; Leigh, R. J.

2017-01-01

A fundamental challenge to the brain is how to prevent intrusive movements when quiet is needed. Unwanted limb movements such as tremor impair fine motor control and unwanted eye drifts such as nystagmus impair vision. A stable platform is also necessary to launch accurate movements. Accordingly, nature has designed control systems with agonist (excitation) and antagonist (inhibition) muscle pairs functioning in push–pull, around a steady level of balanced tonic activity, the set-point. Sensory information can be organized similarly, as in the vestibulo-ocular reflex, which generates eye movements that compensate for head movements. The semicircular canals, working in coplanar pairs, one in each labyrinth, are reciprocally excited and inhibited as they transduce head rotations. The relative change in activity is relayed to the vestibular nuclei, which operate around a set-point of stable balanced activity. When a pathological imbalance occurs, producing unwanted nystagmus without head movement, an adaptive mechanism restores the proper set-point and eliminates the nystagmus. Here we used 90 min of continuous 7 T magnetic field labyrinthine stimulation (MVS) in normal humans to produce sustained nystagmus simulating vestibular imbalance. We identified multiple time-scale processes towards a new zero set-point showing that MVS is an excellent paradigm to investigate the neurobiology of set-point adaptation. This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’. PMID:28242733

Direct evidence for a position input to the smooth pursuit system.

PubMed

Blohm, Gunnar; Missal, Marcus; Lefèvre, Philippe

2005-07-01

When objects move in our environment, the orientation of the visual axis in space requires the coordination of two types of eye movements: saccades and smooth pursuit. The principal input to the saccadic system is position error, whereas it is velocity error for the smooth pursuit system. Recently, it has been shown that catch-up saccades to moving targets are triggered and programmed by using velocity error in addition to position error. Here, we show that, when a visual target is flashed during ongoing smooth pursuit, it evokes a smooth eye movement toward the flash. The velocity of this evoked smooth movement is proportional to the position error of the flash; it is neither influenced by the velocity of the ongoing smooth pursuit eye movement nor by the occurrence of a saccade, but the effect is absent if the flash is ignored by the subject. Furthermore, the response started around 85 ms after the flash presentation and decayed with an average time constant of 276 ms. Thus this is the first direct evidence of a position input to the smooth pursuit system. This study shows further evidence for a coupling between saccadic and smooth pursuit systems. It also suggests that there is an interaction between position and velocity error signals in the control of more complex movements.

Memory and prediction in natural gaze control

PubMed Central

Diaz, Gabriel; Cooper, Joseph; Hayhoe, Mary

2013-01-01

In addition to stimulus properties and task factors, memory is an important determinant of the allocation of attention and gaze in the natural world. One way that the role of memory is revealed is by predictive eye movements. Both smooth pursuit and saccadic eye movements demonstrate predictive effects based on previous experience. We have previously shown that unskilled subjects make highly accurate predictive saccades to the anticipated location of a ball prior to a bounce in a virtual racquetball setting. In this experiment, we examined this predictive behaviour. We asked whether the period after the bounce provides subjects with visual information about the ball trajectory that is used to programme the pursuit movement initiated when the ball passes through the fixation point. We occluded a 100 ms period of the ball's trajectory immediately after the bounce, and found very little effect on the subsequent pursuit movement. Subjects did not appear to modify their strategy to prolong the fixation. Neither were we able to find an effect on interception performance. Thus, it is possible that the occluded trajectory information is not critical for subsequent pursuit, and subjects may use an estimate of the ball's trajectory to programme pursuit. These results provide further support for the role of memory in eye movements. PMID:24018726

The Role of Eye Movement Driven Attention in Functional Strabismic Amblyopia

PubMed Central

2015-01-01

Strabismic amblyopia “blunt vision” is a developmental anomaly that affects binocular vision and results in lowered visual acuity. Strabismus is a term for a misalignment of the visual axes and is usually characterized by impaired ability of the strabismic eye to take up fixation. Such impaired fixation is usually a function of the temporally and spatially impaired binocular eye movements that normally underlie binocular shifts in visual attention. In this review, we discuss how abnormal eye movement function in children with misaligned eyes influences the development of normal binocular visual attention and results in deficits in visual function such as depth perception. We also discuss how eye movement function deficits in adult amblyopia patients can also lead to other abnormalities in visual perception. Finally, we examine how the nonamblyopic eye of an amblyope is also affected in strabismic amblyopia. PMID:25838941

Effects of reward on the accuracy and dynamics of smooth pursuit eye movements.

PubMed

Brielmann, Aenne A; Spering, Miriam

2015-08-01

Reward modulates behavioral choices and biases goal-oriented behavior, such as eye or hand movements, toward locations or stimuli associated with higher rewards. We investigated reward effects on the accuracy and timing of smooth pursuit eye movements in 4 experiments. Eye movements were recorded in participants tracking a moving visual target on a computer monitor. Before target motion onset, a monetary reward cue indicated whether participants could earn money by tracking accurately, or whether the trial was unrewarded (Experiments 1 and 2, n = 11 each). Reward significantly improved eye-movement accuracy across different levels of task difficulty. Improvements were seen even in the earliest phase of the eye movement, within 70 ms of tracking onset, indicating that reward impacts visual-motor processing at an early level. We obtained similar findings when reward was not precued but explicitly associated with the pursuit target (Experiment 3, n = 16); critically, these results were not driven by stimulus prevalence or other factors such as preparation or motivation. Numerical cues (Experiment 4, n = 9) were not effective. (c) 2015 APA, all rights reserved).

Diurnal variation of eye movement and heart rate variability in the human fetus at term.

PubMed

Morokuma, S; Horimoto, N; Satoh, S; Nakano, H

2001-07-01

To elucidate diurnal variations in eye movement and fetal heart rate (FHR) variability in the term fetus, we observed these two parameters continuously for 24 h, using real-time ultrasound and Doppler cardiotocograph, respectively. Studied were five uncomplicated fetuses at term. The time series data of the presence and absence of eye movement and mean FHR value for each 1 min were analyzed using the maximum entropy method (MEM) and subsequent nonlinear least squares fitting. According to the power value of eye movement, all five cases were classified into two groups: three cases in the large power group and two cases in the small power group. The acrophases of eye movement and FHR variability in the large power group were close, thereby implying the existence of a diurnal rhythm in both these parameters and also that they are synchronized. In the small power group, the acrophases were separated. The synchronization of eye movement and FHR variability in the large power group suggests that these phenomena are governed by a common central mechanism related to diurnal rhythm generation.

Opening a Window into Reading Development: Eye Movements' Role Within a Broader Literacy Research Framework.

PubMed

Miller, Brett; O'Donnell, Carol

2013-01-01

The cumulative body of eye movement research provides significant insight into how readers process text. The heart of this work spans roughly 40 years reflecting the maturity of both the topics under study and experimental approaches used to investigate reading. Recent technological advancements offer increased flexibility to the field providing the potential to more concertedly study reading and literacy from an individual differences perspective. Historically, eye movement research focused far less on developmental issues related to individual differences in reading; however, this issue and the broader change it represents signal a meaningful transition inclusive of individual differences. The six papers in this special issue signify the recent, increased attention to and recognition of eye movement research's transition to emphasize individual differences in reading while appreciating early contributions (e.g., Rayner, 1986) in this direction. We introduce these six papers and provide some historical context for the use of eye movement methodology to examine reading and context for the eye movement field's early transition to examining individual differences, culminating in future research recommendations.

Strabismus

MedlinePlus

... do not aim in the same direction Uncoordinated eye movements (eyes do not move together) Loss of vision ... Stahl ED, Ariss MM, Lindquist TP. Disorders of eye movement and alignment. In: Kliegman RM, Stanton BF, St. ...

Frontal eye field, where art thou? Anatomy, function, and non-invasive manipulation of frontal regions involved in eye movements and associated cognitive operations

PubMed Central

Vernet, Marine; Quentin, Romain; Chanes, Lorena; Mitsumasu, Andres; Valero-Cabré, Antoni

2014-01-01

The planning, control and execution of eye movements in 3D space relies on a distributed system of cortical and subcortical brain regions. Within this network, the Eye Fields have been described in animals as cortical regions in which electrical stimulation is able to trigger eye movements and influence their latency or accuracy. This review focuses on the Frontal Eye Field (FEF) a “hub” region located in Humans in the vicinity of the pre-central sulcus and the dorsal-most portion of the superior frontal sulcus. The straightforward localization of the FEF through electrical stimulation in animals is difficult to translate to the healthy human brain, particularly with non-invasive neuroimaging techniques. Hence, in the first part of this review, we describe attempts made to characterize the anatomical localization of this area in the human brain. The outcome of functional Magnetic Resonance Imaging (fMRI), Magneto-encephalography (MEG) and particularly, non-invasive mapping methods such a Transcranial Magnetic Stimulation (TMS) are described and the variability of FEF localization across individuals and mapping techniques are discussed. In the second part of this review, we will address the role of the FEF. We explore its involvement both in the physiology of fixation, saccade, pursuit, and vergence movements and in associated cognitive processes such as attentional orienting, visual awareness and perceptual modulation. Finally in the third part, we review recent evidence suggesting the high level of malleability and plasticity of these regions and associated networks to non-invasive stimulation. The exploratory, diagnostic, and therapeutic interest of such interventions for the modulation and improvement of perception in 3D space are discussed. PMID:25202241

Perceptual impairment and psychomotor control in virtual laparoscopic surgery.

PubMed

Wilson, Mark R; McGrath, John S; Vine, Samuel J; Brewer, James; Defriend, David; Masters, Richard S W

2011-07-01

It is recognised that one of the major difficulties in performing laparoscopic surgery is the translation of two-dimensional video image information to a three-dimensional working area. However, research has tended to ignore the gaze and eye-hand coordination strategies employed by laparoscopic surgeons as they attempt to overcome these perceptual constraints. This study sought to examine if measures related to tool movements, gaze strategy, and eye-hand coordination (the quiet eye) differentiate between experienced and novice operators performing a two-handed manoeuvres task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Twenty-five right-handed surgeons were categorised as being either experienced (having led more than 60 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The 10 experienced and 15 novice surgeons completed the "two-hand manoeuvres" task from the LAP Mentor basic skills learning environment while wearing a gaze registration system. Performance, movement, gaze, and eye-hand coordination parameters were recorded and compared between groups. The experienced surgeons completed the task significantly more quickly than the novices, used significantly fewer movements, and displayed shorter tool paths. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. A more detailed analysis of a difficult subcomponent of the task revealed that experienced operators used a significantly longer aiming fixation (the quiet eye period) to guide precision grasping movements and hence needed fewer grasp attempts. The findings of the study provide further support for the utility of examining strategic gaze behaviour and eye-hand coordination measures to help further our understanding of how experienced surgeons attempt to overcome the perceptual difficulties inherent in the laparoscopic environment.

An Analysis of the Time Course of Lexical Processing During Reading.

PubMed

Sheridan, Heather; Reichle, Erik D

2016-04-01

Reingold, Reichle, Glaholt, and Sheridan (2012) reported a gaze-contingent eye-movement experiment in which survival-curve analyses were used to examine the effects of word frequency, the availability of parafoveal preview, and initial fixation location on the time course of lexical processing. The key results of these analyses suggest that lexical processing begins very rapidly (after approximately 120 ms) and is supported by substantial parafoveal processing (more than 100 ms). Because it is not immediately obvious that these results are congruent with the theoretical assumption that words are processed and identified in a strictly serial manner, we attempted to simulate the experiment using the E-Z Reader model of eye-movement control (Reichle, 2011). These simulations were largely consistent with the empirical results, suggesting that parafoveal processing does play an important functional role by allowing lexical processing to occur rapidly enough to mediate direct control over when the eyes move during reading. Copyright © 2015 Cognitive Science Society, Inc.

Ocular attention-sensing interface system

NASA Technical Reports Server (NTRS)

Zaklad, Allen; Glenn, Floyd A., III; Iavecchia, Helene P.; Stokes, James M.

1986-01-01

The purpose of the research was to develop an innovative human-computer interface based on eye movement and voice control. By eliminating a manual interface (keyboard, joystick, etc.), OASIS provides a control mechanism that is natural, efficient, accurate, and low in workload.

Delayed Anticipatory Spoken Language Processing in Adults with Dyslexia—Evidence from Eye-tracking.

PubMed

Huettig, Falk; Brouwer, Susanne

2015-05-01

It is now well established that anticipation of upcoming input is a key characteristic of spoken language comprehension. It has also frequently been observed that literacy influences spoken language processing. Here, we investigated whether anticipatory spoken language processing is related to individuals' word reading abilities. Dutch adults with dyslexia and a control group participated in two eye-tracking experiments. Experiment 1 was conducted to assess whether adults with dyslexia show the typical language-mediated eye gaze patterns. Eye movements of both adults with and without dyslexia closely replicated earlier research: spoken language is used to direct attention to relevant objects in the environment in a closely time-locked manner. In Experiment 2, participants received instructions (e.g., 'Kijk naar de(COM) afgebeelde piano(COM)', look at the displayed piano) while viewing four objects. Articles (Dutch 'het' or 'de') were gender marked such that the article agreed in gender only with the target, and thus, participants could use gender information from the article to predict the target object. The adults with dyslexia anticipated the target objects but much later than the controls. Moreover, participants' word reading scores correlated positively with their anticipatory eye movements. We conclude by discussing the mechanisms by which reading abilities may influence predictive language processing. Copyright © 2015 John Wiley & Sons, Ltd.

Neural Correlates of Fixation Duration during Real-world Scene Viewing: Evidence from Fixation-related (FIRE) fMRI.

PubMed

Henderson, John M; Choi, Wonil

2015-06-01

During active scene perception, our eyes move from one location to another via saccadic eye movements, with the eyes fixating objects and scene elements for varying amounts of time. Much of the variability in fixation duration is accounted for by attentional, perceptual, and cognitive processes associated with scene analysis and comprehension. For this reason, current theories of active scene viewing attempt to account for the influence of attention and cognition on fixation duration. Yet almost nothing is known about the neurocognitive systems associated with variation in fixation duration during scene viewing. We addressed this topic using fixation-related fMRI, which involves coregistering high-resolution eye tracking and magnetic resonance scanning to conduct event-related fMRI analysis based on characteristics of eye movements. We observed that activation in visual and prefrontal executive control areas was positively correlated with fixation duration, whereas activation in ventral areas associated with scene encoding and medial superior frontal and paracentral regions associated with changing action plans was negatively correlated with fixation duration. The results suggest that fixation duration in scene viewing is controlled by cognitive processes associated with real-time scene analysis interacting with motor planning, consistent with current computational models of active vision for scene perception.

Visual Contrast Sensitivity in Early-Stage Parkinson's Disease.

PubMed

Ming, Wendy; Palidis, Dimitrios J; Spering, Miriam; McKeown, Martin J

2016-10-01

Visual impairments are frequent in Parkinson's disease (PD) and impact normal functioning in daily activities. Visual contrast sensitivity is a powerful nonmotor sign for discriminating PD patients from controls. However, it is usually assessed with static visual stimuli. Here we examined the interaction between perception and eye movements in static and dynamic contrast sensitivity tasks in a cohort of mildly impaired, early-stage PD patients. Patients (n = 13) and healthy age-matched controls (n = 12) viewed stimuli of various spatial frequencies (0-8 cyc/deg) and speeds (0°/s, 10°/s, 30°/s) on a computer monitor. Detection thresholds were determined by asking participants to adjust luminance contrast until they could just barely see the stimulus. Eye position was recorded with a video-based eye tracker. Patients' static contrast sensitivity was impaired in the intermediate spatial-frequency range and this impairment correlated with fixational instability. However, dynamic contrast sensitivity and patients' smooth pursuit were relatively normal. An independent component analysis revealed contrast sensitivity profiles differentiating patients and controls. Our study simultaneously assesses perceptual contrast sensitivity and eye movements in PD, revealing a possible link between fixational instability and perceptual deficits. Spatiotemporal contrast sensitivity profiles may represent an easily measurable metric as a component of a broader combined biometric for nonmotor features observed in PD.

Changes to Saccade Behaviors in Parkinson’s Disease Following Dancing and Observation of Dancing

PubMed Central

Cameron, Ian G. M.; Brien, Donald C.; Links, Kira; Robichaud, Sarah; Ryan, Jennifer D.; Munoz, Douglas P.; Chow, Tiffany W.

2012-01-01

Background: The traditional view of Parkinson’s disease (PD) as a motor disorder only treated by dopaminergic medications is now shifting to include non-pharmacologic interventions. We have noticed that patients with PD obtain an immediate, short-lasting benefit to mobility by the end of a dance class, suggesting some mechanism by which dancing reduces bradykinetic symptoms. We have also found that patients with PD are unimpaired at initiating highly automatic eye movements to visual stimuli (pro-saccades) but are impaired at generating willful eye movements away from visual stimuli (anti-saccades). We hypothesized that the mechanisms by which a dance class improves movement initiation may generalize to the brain networks impacted in PD (frontal lobe and basal ganglia, BG), and thus could be assessed objectively by measuring eye movements, which rely on the same neural circuitry. Methods: Participants with PD performed pro- and anti-saccades before, and after, a dance class. “Before” and “after” saccade performance measurements were compared. These measurements were then contrasted with a control condition (observing a dance class in a video), and with older and younger adult populations, who rested for an hour between measurements. Results: We found an improvement in anti-saccade performance following the observation of dance (but not following dancing), but we found a detriment in pro-saccade performance following dancing. Conclusion: We suggest that observation of dance induced plasticity changes in frontal-BG networks that are important for executive control. Dancing, in contrast, increased voluntary movement signals that benefited mobility, but interfered with the automaticity of efficient pro-saccade execution. PMID:23483834

Driving simulation in the clinic: testing visual exploratory behavior in daily life activities in patients with visual field defects.

PubMed

Hamel, Johanna; Kraft, Antje; Ohl, Sven; De Beukelaer, Sophie; Audebert, Heinrich J; Brandt, Stephan A

2012-09-18

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily life, despite similar visual deficits. We assume this could be due to variable development of compensatory strategies such as altered visual scanning behavior. Scanning compensatory therapy (SCT) is studied as part of the visual training after infarction next to vision restoration therapy. SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy(1), not only in natural search tasks but also in mastering daily life activities(2). Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition(3). Martin et al.(4) and Hayhoe et al.(5) showed that behavior demonstrated in a laboratory setting cannot be assigned easily to a natural condition. Hence, our goal was to develop a study set-up which uncovers different compensatory oculomotor strategies quickly in a realistic testing situation: Patients are tested in the clinical environment in a driving simulator. SILAB software (Wuerzburg Institute for Traffic Sciences GmbH (WIVW)) was used to program driving scenarios of varying complexity and recording the driver's performance. The software was combined with a head mounted infrared video pupil tracker, recording head- and eye-movements (EyeSeeCam, University of Munich Hospital, Clinical Neurosciences). The positioning of the patient in the driving simulator and the positioning, adjustment and calibration of the camera is demonstrated. Typical performances of a patient with and without compensatory strategy and a healthy control are illustrated in this pilot study. Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. Compensatory gaze behavior in a patient leads to a driving performance comparable to a healthy control, while the performance of a patient without compensatory behavior is significantly worse. The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential.

Spasmus nutans

MedlinePlus

... infants and young children. It involves rapid, uncontrolled eye movements, head bobbing, and, sometimes, holding the neck in ... spasmus nutans include: Small, quick, side-to-side eye movements called nystagmus (both eyes are involved, but each ...

Brown Syndrome

MedlinePlus

... Does Brown syndrome cause eye problems besides abnormal eye movements? In the more severely affected cases of Brown ... acquired and congenital cases. In congenital cases, the eye movement problem is usually constant and unlikely to resolve ...

Active head rotations and eye-head coordination

NASA Technical Reports Server (NTRS)

Zangemeister, W. H.; Stark, L.

1981-01-01

It is pointed out that head movements play an important role in gaze. The interaction between eye and head movements involves both their shared role in directing gaze and the compensatory vestibular ocular reflex. The dynamics of head trajectories are discussed, taking into account the use of parameterization to obtain the peak velocity, peak accelerations, the times of these extrema, and the duration of the movement. Attention is given to the main sequence, neck muscle EMG and details of the head-movement trajectory, types of head model accelerations, the latency of eye and head movement in coordinated gaze, gaze latency as a function of various factors, and coordinated gaze types. Clinical examples of gaze-plane analysis are considered along with the instantaneous change of compensatory eye movement (CEM) gain, and aspects of variability.

Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods.

PubMed

Nickel, Allison E; Henke, Katharina; Hannula, Deborah E

2015-01-01

While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test); for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test). Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness.

Ankle sprain as a work-related accident: status of proprioception after 2 weeks

PubMed Central

González-Iñigo, Salvador; Lafuente-Sotillos, Guillermo

2017-01-01

Purpose This study aims at verifying whether proprioception is abnormal or not, two weeks after a grade 1 and 2 ankle sprain in the scope of work-related accident. Methods A descriptive, observation and transversal study was designed to compare speed, movement and oscilation of centre of pressure in employees of companies signed up to a mutual company. Participants’ healthy feet comprised the control group, and feet that had undergone an ankle sprain due to a work-related accident comprised the cases group. The following stability tests were undertaken to both the healthy and injuried feet using a force plate: Monopodal Romberg test with eyes open, Monopodal Romberg test with eyes open on a 30 mm thick foam rubber, Monopodal Romberg test with eyes closed, and Romberg test as monopodal support with eyes closed on a 30 mm thick foam rubber. A multiple logistic regression analysis was performed. From the results of this regression model the COR curve test was performed. Results 71.7% accuracy in the predictions was attained. The equation was as follows: Condition (injured or healthy) = 0.052⋅% RGC AP Movement − 0.81⋅MREO AP Movement. The variable MREO antero-posterior movement was used in the COR curve methodology. The area under the curve was greater than 0.65 and at a 95% confidence interval the 0.75 value was included, which in our case was the injured subject condition. Values for sensitivity, specificity, positive predictive value and negative predictive value were 0.667, 0.633, 64.5%, and 65.5%, respectively. Conclusion The participants in this study showed a diminished capacity for postural control in an ankle two weeks after an ankle sprain. PMID:29259844

Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods

PubMed Central

Nickel, Allison E.; Henke, Katharina; Hannula, Deborah E.

2015-01-01

While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test); for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test). Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness. PMID:26512726

Error correcting mechanisms during antisaccades: contribution of online control during primary saccades and offline control via secondary saccades.

PubMed

Bedi, Harleen; Goltz, Herbert C; Wong, Agnes M F; Chandrakumar, Manokaraananthan; Niechwiej-Szwedo, Ewa

2013-01-01

Errors in eye movements can be corrected during the ongoing saccade through in-flight modifications (i.e., online control), or by programming a secondary eye movement (i.e., offline control). In a reflexive saccade task, the oculomotor system can use extraretinal information (i.e., efference copy) online to correct errors in the primary saccade, and offline retinal information to generate a secondary corrective saccade. The purpose of this study was to examine the error correction mechanisms in the antisaccade task. The roles of extraretinal and retinal feedback in maintaining eye movement accuracy were investigated by presenting visual feedback at the spatial goal of the antisaccade. We found that online control for antisaccade is not affected by the presence of visual feedback; that is whether visual feedback is present or not, the duration of the deceleration interval was extended and significantly correlated with reduced antisaccade endpoint error. We postulate that the extended duration of deceleration is a feature of online control during volitional saccades to improve their endpoint accuracy. We found that secondary saccades were generated more frequently in the antisaccade task compared to the reflexive saccade task. Furthermore, we found evidence for a greater contribution from extraretinal sources of feedback in programming the secondary "corrective" saccades in the antisaccade task. Nonetheless, secondary saccades were more corrective for the remaining antisaccade amplitude error in the presence of visual feedback of the target. Taken together, our results reveal a distinctive online error control strategy through an extension of the deceleration interval in the antisaccade task. Target feedback does not improve online control, rather it improves the accuracy of secondary saccades in the antisaccade task.

Error Correcting Mechanisms during Antisaccades: Contribution of Online Control during Primary Saccades and Offline Control via Secondary Saccades

PubMed Central

Bedi, Harleen; Goltz, Herbert C.; Wong, Agnes M. F.; Chandrakumar, Manokaraananthan; Niechwiej-Szwedo, Ewa

2013-01-01

Errors in eye movements can be corrected during the ongoing saccade through in-flight modifications (i.e., online control), or by programming a secondary eye movement (i.e., offline control). In a reflexive saccade task, the oculomotor system can use extraretinal information (i.e., efference copy) online to correct errors in the primary saccade, and offline retinal information to generate a secondary corrective saccade. The purpose of this study was to examine the error correction mechanisms in the antisaccade task. The roles of extraretinal and retinal feedback in maintaining eye movement accuracy were investigated by presenting visual feedback at the spatial goal of the antisaccade. We found that online control for antisaccade is not affected by the presence of visual feedback; that is whether visual feedback is present or not, the duration of the deceleration interval was extended and significantly correlated with reduced antisaccade endpoint error. We postulate that the extended duration of deceleration is a feature of online control during volitional saccades to improve their endpoint accuracy. We found that secondary saccades were generated more frequently in the antisaccade task compared to the reflexive saccade task. Furthermore, we found evidence for a greater contribution from extraretinal sources of feedback in programming the secondary “corrective” saccades in the antisaccade task. Nonetheless, secondary saccades were more corrective for the remaining antisaccade amplitude error in the presence of visual feedback of the target. Taken together, our results reveal a distinctive online error control strategy through an extension of the deceleration interval in the antisaccade task. Target feedback does not improve online control, rather it improves the accuracy of secondary saccades in the antisaccade task. PMID:23936308

Face value: eye movements and the evaluation of facial crowds in social anxiety.

PubMed

Lange, Wolf-Gero; Heuer, Kathrin; Langner, Oliver; Keijsers, Ger P J; Becker, Eni S; Rinck, Mike

2011-09-01

Scientific evidence is equivocal on whether Social Anxiety Disorder (SAD) is characterized by a biased negative evaluation of (grouped) facial expressions, even though it is assumed that such a bias plays a crucial role in the maintenance of the disorder. To shed light on the underlying mechanisms of face evaluation in social anxiety, the eye movements of 22 highly socially anxious (SAs) and 21 non-anxious controls (NACs) were recorded while they rated the degree of friendliness of neutral-angry and smiling-angry face combinations. While the Crowd Rating Task data showed no significant differences between SAs and NACs, the resultant eye-movement patterns revealed that SAs, compared to NACs, looked away faster when the face first fixated was angry. Additionally, in SAs the proportion of fixated angry faces was significantly higher than for other expressions. Independent of social anxiety, these fixated angry faces were the best predictor of subsequent affect ratings for either group. Angry faces influence attentional processes such as eye movements in SAs and by doing so reflect biased evaluations. As these processes do not correlate with explicit ratings of faces, however, it remains unclear at what point implicit attentional behaviors lead to anxiety-prone behaviors and the maintenance of SAD. The relevance of these findings is discussed in the light of the current theories. Copyright © 2011 Elsevier Ltd. All rights reserved.

Eye Tracking Based Control System for Natural Human-Computer Interaction

PubMed Central

Lin, Shu-Fan

2017-01-01

Eye movement can be regarded as a pivotal real-time input medium for human-computer communication, which is especially important for people with physical disability. In order to improve the reliability, mobility, and usability of eye tracking technique in user-computer dialogue, a novel eye control system with integrating both mouse and keyboard functions is proposed in this paper. The proposed system focuses on providing a simple and convenient interactive mode by only using user's eye. The usage flow of the proposed system is designed to perfectly follow human natural habits. Additionally, a magnifier module is proposed to allow the accurate operation. In the experiment, two interactive tasks with different difficulty (searching article and browsing multimedia web) were done to compare the proposed eye control tool with an existing system. The Technology Acceptance Model (TAM) measures are used to evaluate the perceived effectiveness of our system. It is demonstrated that the proposed system is very effective with regard to usability and interface design. PMID:29403528

Relationship between abstract thinking and eye gaze pattern in patients with schizophrenia.

PubMed

Oh, Jooyoung; Chun, Ji-Won; Lee, Jung Suk; Kim, Jae-Jin

2014-04-16

Effective integration of visual information is necessary to utilize abstract thinking, but patients with schizophrenia have slow eye movement and usually explore limited visual information. This study examines the relationship between abstract thinking ability and the pattern of eye gaze in patients with schizophrenia using a novel theme identification task. Twenty patients with schizophrenia and 22 healthy controls completed the theme identification task, in which subjects selected which word, out of a set of provided words, best described the theme of a picture. Eye gaze while performing the task was recorded by the eye tracker. Patients exhibited a significantly lower correct rate for theme identification and lesser fixation and saccade counts than controls. The correct rate was significantly correlated with the fixation count in patients, but not in controls. Patients with schizophrenia showed impaired abstract thinking and decreased quality of gaze, which were positively associated with each other. Theme identification and eye gaze appear to be useful as tools for the objective measurement of abstract thinking in patients with schizophrenia.

Eye Tracking Based Control System for Natural Human-Computer Interaction.

PubMed

Zhang, Xuebai; Liu, Xiaolong; Yuan, Shyan-Ming; Lin, Shu-Fan

2017-01-01

Eye movement can be regarded as a pivotal real-time input medium for human-computer communication, which is especially important for people with physical disability. In order to improve the reliability, mobility, and usability of eye tracking technique in user-computer dialogue, a novel eye control system with integrating both mouse and keyboard functions is proposed in this paper. The proposed system focuses on providing a simple and convenient interactive mode by only using user's eye. The usage flow of the proposed system is designed to perfectly follow human natural habits. Additionally, a magnifier module is proposed to allow the accurate operation. In the experiment, two interactive tasks with different difficulty (searching article and browsing multimedia web) were done to compare the proposed eye control tool with an existing system. The Technology Acceptance Model (TAM) measures are used to evaluate the perceived effectiveness of our system. It is demonstrated that the proposed system is very effective with regard to usability and interface design.

The horizontal and vertical cervico-ocular reflexes of the rabbit.

PubMed

Barmack, N H; Nastos, M A; Pettorossi, V E

1981-11-16

Horizontal and vertical cervico-ocular reflexes of the rabbit (HCOR, VCOR) were evoked by sinusoidal oscillation of the body about the vertical and longitudinal axes while the head was fixed. These reflexes were studied over a frequency range of 0.005-0.800 Hz and at stimulus amplitudes of +/- 10 degrees. When the body of the rabbit was rotated horizontally clockwise around the fixed head, clockwise conjugate eye movements were evoked. When the body was rotated about the longitudinal axis onto the right side, the right eye rotated down and the left eye rotated up. The mean gain of the HCOR (eye velocity/body velocity) rose from 0.21 and 0.005 Hz to 0.27 at 0.020 Hz and then declined to 0.06 at 0.3Hz. The gain of the VCOR was less than the gain of the HCOR by a factor of 2-3. The HCOR was measured separately and in combination with the horizontal vestibulo-ocular reflex (HVOR). These reflexes combine linearly. The relative movements of the first 3 cervical vertebrae during stimulation of the HCOR and VCOR were measured. For the HCOR, the largest angular displacement (74%) occurs between C1 and C2. For the VCOR, the largest relative angular displacement (45%) occurs between C2 and C3. Step horizontal clockwise rotation of the head and body (HVOR) evoked low velocity counterclockwise eye movements followed by fast clockwise (resetting) eye movements. Step horizontal clockwise rotation of the body about the fixed head (HCOR) evoked low velocity clockwise eye movements which were followed by fast clockwise eye movements. Step horizontal clockwise rotation of the head about the fixed body (HCOR + HVOR) evoked low velocity counterclockwise eye movements which were not interrupted by fast clockwise eye movements. These data provide further evidence for a linear combination of independent HCOR and HVOR signals.

Assessment of Attentional Workload while Driving by Eye-fixation-related Potentials

NASA Astrophysics Data System (ADS)

Takeda, Yuji; Yoshitsugu, Noritoshi; Itoh, Kazuya; Kanamori, Nobuhiro

How do drivers cope with the attentional workload of in-vehicle information technology? In the present study, we propose a new psychophysiological measure for assessing drivers' attention: eye-fixation-related potential (EFRP). EFRP is a kind of event-related brain potential measurable at the eye-movement situation that reflects how closely observers examine visual information at the eye-fixated position. In the experiment, the effects of verbal working memory load and spatial working memory load during simulated driving were examined by measuring the number of saccadic eye-movements and EFRP as the indices of drivers' attention. The results showed that the spatial working memory load affected both the number of saccadic eye-movements and the amplitude of the P100 component of EFRP, whereas the verbal working memory load affected only the number of saccadic eye-movements. This implies that drivers can perform time-sharing processing between driving and the verbal working memory task, but the decline of accuracy of visual processing during driving is inescapable when the spatial working memory load is given. The present study suggests that EFRP can provide a new index of drivers' attention, other than saccadic eye-movements.

EYE MOVEMENT RECORDING AND NONLINEAR DYNAMICS ANALYSIS – THE CASE OF SACCADES#

PubMed Central

Aştefănoaei, Corina; Pretegiani, Elena; Optican, L.M.; Creangă, Dorina; Rufa, Alessandra

2015-01-01

Evidence of a chaotic behavioral trend in eye movement dynamics was examined in the case of a saccadic temporal series collected from a healthy human subject. Saccades are highvelocity eye movements of very short duration, their recording being relatively accessible, so that the resulting data series could be studied computationally for understanding the neural processing in a motor system. The aim of this study was to assess the complexity degree in the eye movement dynamics. To do this we analyzed the saccadic temporal series recorded with an infrared camera eye tracker from a healthy human subject in a special experimental arrangement which provides continuous records of eye position, both saccades (eye shifting movements) and fixations (focusing over regions of interest, with rapid, small fluctuations). The semi-quantitative approach used in this paper in studying the eye functioning from the viewpoint of non-linear dynamics was accomplished by some computational tests (power spectrum, portrait in the state space and its fractal dimension, Hurst exponent and largest Lyapunov exponent) derived from chaos theory. A high complexity dynamical trend was found. Lyapunov largest exponent test suggested bi-stability of cellular membrane resting potential during saccadic experiment. PMID:25698889

Magnifying visual target information and the role of eye movements in motor sequence learning.

PubMed

Massing, Matthias; Blandin, Yannick; Panzer, Stefan

2016-01-01

An experiment investigated the influence of eye movements on learning a simple motor sequence task when the visual display was magnified. The task was to reproduce a 1300 ms spatial-temporal pattern of elbow flexions and extensions. The spatial-temporal pattern was displayed in front of the participants. Participants were randomly assigned to four groups differing on eye movements (free to use their eyes/instructed to fixate) and the visual display (small/magnified). All participants had to perform a pre-test, an acquisition phase, a delayed retention test, and a transfer test. The results indicated that participants in each practice condition increased their performance during acquisition. The participants who were permitted to use their eyes in the magnified visual display outperformed those who were instructed to fixate on the magnified visual display. When a small visual display was used, the instruction to fixate induced no performance decrements compared to participants who were permitted to use their eyes during acquisition. The findings demonstrated that a spatial-temporal pattern can be learned without eye movements, but being permitting to use eye movements facilitates the response production when the visual angle is increased. Copyright © 2015 Elsevier B.V. All rights reserved.

The reticular formation.

PubMed

Horn, Anja K E

2006-01-01

The reticular formation of the brainstem contains functional cell groups that are important for the control of eye, head, or lid movements. The mesencephalic reticular formation is primarily involved in the control of vertical gaze, the paramedian pontine reticular formation in horizontal gaze, and the medullary pontine reticular formation in head movements and gaze holding. In this chapter, the locations, connections, and histochemical properties of the functional cell groups are reviewed and correlated with specific subdivisions of the reticular formation.

Eye and Head Response to Peripheral Targets

DTIC Science & Technology

1989-08-01

nystagmus movements of the eyes. These move- ments tend to be oscillatory or unstable in nature and can be elicited in three ways: stimuli 2 in the...Hall and Cusack, 1972). Nystagmus can best be described through example. As mentioned previously, the com- pensatory eye movements serve to stabilize...movements are what are referred to as nystagmus . The direction of the nystagmus is identified by the movement of the fast phase, that is, the direction

Eye muscle repair

MedlinePlus

... and physical exam before the procedure Orthoptic measurements (eye movement measurements) Always tell your child's health care provider: ... D, Plummer LS, Stass-Isern M. Disorders of eye movement and alignment. In: Kliegman RM, Stanton BF, St. ...

Altered visual strategies and attention are related to increased force fluctuations during a pinch grip task in older adults.

PubMed

Keenan, Kevin G; Huddleston, Wendy E; Ernest, Bradley E

2017-11-01

The purpose of the study was to determine the visual strategies used by older adults during a pinch grip task and to assess the relations between visual strategy, deficits in attention, and increased force fluctuations in older adults. Eye movements of 23 older adults (>65 yr) were monitored during a low-force pinch grip task while subjects viewed three common visual feedback displays. Performance on the Grooved Pegboard test and an attention task (which required no concurrent hand movements) was also measured. Visual strategies varied across subjects and depended on the type of visual feedback provided to the subjects. First, while viewing a high-gain compensatory feedback display (horizontal bar moving up and down with force), 9 of 23 older subjects adopted a strategy of performing saccades during the task, which resulted in 2.5 times greater force fluctuations in those that exhibited saccades compared with those who maintained fixation near the target line. Second, during pursuit feedback displays (force trace moving left to right across screen and up and down with force), all subjects exhibited multiple saccades, and increased force fluctuations were associated ( r s = 0.6; P = 0.002) with fewer saccades during the pursuit task. Also, decreased low-frequency (<4 Hz) force fluctuations and Grooved Pegboard times were significantly related ( P = 0.033 and P = 0.005, respectively) with higher (i.e., better) attention z scores. Comparison of these results with our previously published results in young subjects indicates that saccadic eye movements and attention are related to force control in older adults. NEW & NOTEWORTHY The significant contributions of the study are the addition of eye movement data and an attention task to explain differences in hand motor control across different visual displays in older adults. Older participants used different visual strategies across varying feedback displays, and saccadic eye movements were related with motor performance. In addition, those older individuals with deficits in attention had impaired motor performance on two different hand motor control tasks, including the Grooved Pegboard test. Copyright © 2017 the American Physiological Society.

Rapid and coordinated processing of global motion images by local clusters of retinal ganglion cells.

PubMed

Matsumoto, Akihiro; Tachibana, Masao

2017-01-01

Even when the body is stationary, the whole retinal image is always in motion by fixational eye movements and saccades that move the eye between fixation points. Accumulating evidence indicates that the brain is equipped with specific mechanisms for compensating for the global motion induced by these eye movements. However, it is not yet fully understood how the retina processes global motion images during eye movements. Here we show that global motion images evoke novel coordinated firing in retinal ganglion cells (GCs). We simultaneously recorded the firing of GCs in the goldfish isolated retina using a multi-electrode array, and classified each GC based on the temporal profile of its receptive field (RF). A moving target that accompanied the global motion (simulating a saccade following a period of fixational eye movements) modulated the RF properties and evoked synchronized and correlated firing among local clusters of the specific GCs. Our findings provide a novel concept for retinal information processing during eye movements.

Very Slow Search and Reach: Failure to Maximize Expected Gain in an Eye-Hand Coordination Task

PubMed Central

Zhang, Hang; Morvan, Camille; Etezad-Heydari, Louis-Alexandre; Maloney, Laurence T.

2012-01-01

We examined an eye-hand coordination task where optimal visual search and hand movement strategies were inter-related. Observers were asked to find and touch a target among five distractors on a touch screen. Their reward for touching the target was reduced by an amount proportional to how long they took to locate and reach to it. Coordinating the eye and the hand appropriately would markedly reduce the search-reach time. Using statistical decision theory we derived the sequence of interrelated eye and hand movements that would maximize expected gain and we predicted how hand movements should change as the eye gathered further information about target location. We recorded human observers' eye movements and hand movements and compared them with the optimal strategy that would have maximized expected gain. We found that most observers failed to adopt the optimal search-reach strategy. We analyze and describe the strategies they did adopt. PMID:23071430

Eye Movements Reveal the Influence of Event Structure on Reading Behavior.

PubMed

Swets, Benjamin; Kurby, Christopher A

2016-03-01

When we read narrative texts such as novels and newspaper articles, we segment information presented in such texts into discrete events, with distinct boundaries between those events. But do our eyes reflect this event structure while reading? This study examines whether eye movements during the reading of discourse reveal how readers respond online to event structure. Participants read narrative passages as we monitored their eye movements. Several measures revealed that event structure predicted eye movements. In two experiments, we found that both early and overall reading times were longer for event boundaries. We also found that regressive saccades were more likely to land on event boundaries, but that readers were less likely to regress out of an event boundary. Experiment 2 also demonstrated that tracking event structure carries a working memory load. Eye movements provide a rich set of online data to test the cognitive reality of event segmentation during reading. Copyright © 2015 Cognitive Science Society, Inc.

Time-course of eye movement-related decrease in vividness and emotionality of unpleasant autobiographical memories.

PubMed

Smeets, Monique A M; Dijs, M Willem; Pervan, Iva; Engelhard, Iris M; van den Hout, Marcel A

2012-01-01

The time-course of changes in vividness and emotionality of unpleasant autobiographical memories associated with making eye movements (eye movement desensitisation and reprocessing, EMDR) was investigated. Participants retrieved unpleasant autobiographical memories and rated their vividness and emotionality prior to and following 96 seconds of making eye movements (EM) or keeping eyes stationary (ES); at 2, 4, 6, and 10 seconds into the intervention; then followed by regular larger intervals throughout the 96-second intervention. Results revealed a significant drop compared to the ES group in emotionality after 74 seconds compared to a significant drop in vividness at only 2 seconds into the intervention. These results support that emotionality becomes reduced only after vividness has dropped. The results are discussed in light of working memory theory and visual imagery theory, following which the regular refreshment of the visual memory needed to maintain it in working memory is interfered with by eye movements that also tax working memory, which affects vividness first.

Combining EEG and eye tracking: identification, characterization, and correction of eye movement artifacts in electroencephalographic data

PubMed Central

Plöchl, Michael; Ossandón, José P.; König, Peter

2012-01-01

Eye movements introduce large artifacts to electroencephalographic recordings (EEG) and thus render data analysis difficult or even impossible. Trials contaminated by eye movement and blink artifacts have to be discarded, hence in standard EEG-paradigms subjects are required to fixate on the screen. To overcome this restriction, several correction methods including regression and blind source separation have been proposed. Yet, there is no automated standard procedure established. By simultaneously recording eye movements and 64-channel-EEG during a guided eye movement paradigm, we investigate and review the properties of eye movement artifacts, including corneo-retinal dipole changes, saccadic spike potentials and eyelid artifacts, and study their interrelations during different types of eye- and eyelid movements. In concordance with earlier studies our results confirm that these artifacts arise from different independent sources and that depending on electrode site, gaze direction, and choice of reference these sources contribute differently to the measured signal. We assess the respective implications for artifact correction methods and therefore compare the performance of two prominent approaches, namely linear regression and independent component analysis (ICA). We show and discuss that due to the independence of eye artifact sources, regression-based correction methods inevitably over- or under-correct individual artifact components, while ICA is in principle suited to address such mixtures of different types of artifacts. Finally, we propose an algorithm, which uses eye tracker information to objectively identify eye-artifact related ICA-components (ICs) in an automated manner. In the data presented here, the algorithm performed very similar to human experts when those were given both, the topographies of the ICs and their respective activations in a large amount of trials. Moreover it performed more reliable and almost twice as effective than human experts when those had to base their decision on IC topographies only. Furthermore, a receiver operating characteristic (ROC) analysis demonstrated an optimal balance of false positive and false negative at an area under curve (AUC) of more than 0.99. Removing the automatically detected ICs from the data resulted in removal or substantial suppression of ocular artifacts including microsaccadic spike potentials, while the relevant neural signal remained unaffected. In conclusion the present work aims at a better understanding of individual eye movement artifacts, their interrelations and the respective implications for eye artifact correction. Additionally, the proposed ICA-procedure provides a tool for optimized detection and correction of eye movement-related artifact components. PMID:23087632

The contributions of eye movements to the efficacy of brief exposure treatment for reducing fear of public speaking.

PubMed

Carrigan, M H; Levis, D J

1999-01-01

The present study was designed to isolate the effects of the eye-movement component of the Eye Movement Desensitization and Reprocessing (EMDR) procedure in the treatment of fear of public speaking. Seventy-one undergraduate psychology students who responded in a fearful manner on the Fear Survey Schedule II and on a standardized, self-report measure of public speaking anxiety (Personal Report of Confidence as a Speaker; PRCS) were randomly assigned to one of four groups in a 2x2 factorial design. The two independent variables assessed were treatment condition (imagery plus eye movements vs. imagery alone) and type of imagery (fear-relevant vs. relaxing). Dependent variables assessed were self-reported and physiological anxiety during exposure and behavioral indices of anxiety while giving a speech. Although process measures indicated exposure to fear-relevant imagery increased anxiety during the procedure, no significant differences among groups were found on any of the outcome measures, except that participants who received eye movements were less likely to give a speech posttreatment than participants who did not receive eye movements. Addition of the eye movements to the experimental procedure did not result in enhancement of fear reduction. It was concluded, consistent with the results of past research, that previously reported positive effects of the EMDR procedure may be largely due to exposure to conditioned stimuli.

Disturbed Dreaming and the Instability of Sleep: Altered Nonrapid Eye Movement Sleep Microstructure in Individuals with Frequent Nightmares as Revealed by the Cyclic Alternating Pattern

PubMed Central

Simor, Péter; Bódizs, Róbert; Horváth, Klára; Ferri, Raffaele

2013-01-01

Study Objectives: Nightmares are disturbing mental experiences during sleep that usually result in abrupt awakenings. Frequent nightmares are associated with poor subjective sleep quality, and recent polysomnographic data suggest that nightmare sufferers exhibit impaired sleep continuity during nonrapid eye movement (NREM) sleep. Because disrupted sleep might be related to abnormal arousal processes, the goal of this study was to examine polysomnographic arousal-related activities in a group of nightmare sufferers and a healthy control group. Design: Sleep microstructure analysis was carried out by scoring the cyclic alternating pattern (CAP) in NREM sleep and the arousal index in rapid eye movement (REM) sleep on the second night of the polysomnographic examination. Setting: Hospital-based sleep research laboratory. Participants: There were 17 in the nightmare (NMs) group and 23 in the healthy control (CTLs) group. Interventions: N/A. Measurements and Results: The NMs group exhibited reduced amounts of CAP A1 subtype and increased CAP A2 and A3 subtypes, as well as longer duration of CAP A phases in comparison with CTLs. Moreover, these differences remained significant after controlling for the confounding factors of anxious and depressive symptoms. The absolute number and frequency of REM arousals did not differ significantly between the two groups. Conclusions: The results of our study indicate that NREM sleep microstructure is altered during nonsymptomatic nights of nightmares. Disrupted sleep in the NMs group seems to be related to abnormal arousal processes, specifically an imbalance in sleep-promoting and arousing mechanisms during sleep. Citation: Simor P; Bódizs R; Horváth K; Ferri R. Disturbed dreaming and the instability of sleep: altered nonrapid eye movement sleep microstructure in individuals with frequent nightmares as revealed by the cyclic alternating pattern. SLEEP 2013;36(3):413-419. PMID:23449753

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2.

PubMed

Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R; Knudsen, Stine

2017-02-15

Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy. © 2017 American Academy of Sleep Medicine

Interaction of semicircular canal stimulation with carotid baroreceptor reflex control of heart rate

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1998-01-01

The carotid-cardiac baroreflex contributes to the prediction of orthostatic tolerance; experimental attenuation of the reflex response leads to orthostatic hypotension in humans and animals. Anecdotal observations indicate that rotational head movements about the vertical axis of the body can also induce orthostatic bradycardia and hypotension through increased parasympathetic activity. We therefore measured the chronotropic response to carotid baroreceptor stimulation in 12 men during varying conditions of vestibulo-oculomotor stimulation to test the hypothesis that stimulation of the semicircular canals associated with head movements in the yaw plane inhibits cardioacceleration through a vagally mediated baroreflex. Carotid-cardiac baroreflex response was assessed by plotting R-R intervals (ms) at each of 8 neck pressure steps with their respective carotid distending pressures (mmHg). Calculated baroreflex gain (maximal slope of the stimulus-response relationship) was measured under 4 experimental conditions: 1) sinusoidal whole-body yaw rotation of the subject in the dark without visual fixation (combined vestibular-oculomotor stimulation); 2) yaw oscillation of the subject while tracking a small head-fixed light moving with the subject (vestibular stimulation without eye movements); 3) subject stationary while fixating on a small light oscillating in yaw at the same frequency, peak acceleration, and velocity as the chair (eye movements without vestibular stimulation); and 4) subject stationary in the dark (no eye or head motion). Head motion alone and with eye movement reduced baseline baroreflex responsiveness to the same stimulus by 30%. Inhibition of cardioacceleration during rotational head movements may have significant impact on functional performance in aerospace environments, particularly in high-performance aircraft pilots during high angular acceleration in aerial combat maneuvers or in astronauts upon return from spaceflight who already have attenuated baroreflex functions.

Geometry and Gesture-Based Features from Saccadic Eye-Movement as a Biometric in Radiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammond, Tracy; Tourassi, Georgia; Yoon, Hong-Jun

In this study, we present a novel application of sketch gesture recognition on eye-movement for biometric identification and estimating task expertise. The study was performed for the task of mammographic screening with simultaneous viewing of four coordinated breast views as typically done in clinical practice. Eye-tracking data and diagnostic decisions collected for 100 mammographic cases (25 normal, 25 benign, 50 malignant) and 10 readers (three board certified radiologists and seven radiology residents), formed the corpus for this study. Sketch gesture recognition techniques were employed to extract geometric and gesture-based features from saccadic eye-movements. Our results show that saccadic eye-movement, characterizedmore » using sketch-based features, result in more accurate models for predicting individual identity and level of expertise than more traditional eye-tracking features.« less

Tracking the Eye Movement of Four Years Old Children Learning Chinese Words

ERIC Educational Resources Information Center

Lin, Dan; Chen, Guangyao; Liu, Yingyi; Liu, Jiaxin; Pan, Jue; Mo, Lei

2018-01-01

Storybook reading is the major source of literacy exposure for beginning readers. The present study tracked 4-year-old Chinese children's eye movements while they were reading simulated storybook pages. Their eye-movement patterns were examined in relation to their word learning gains. The same reading list, consisting of 20 two-character Chinese…

Influence of Eye Movements, Auditory Perception, and Phonemic Awareness in the Reading Process

ERIC Educational Resources Information Center

Megino-Elvira, Laura; Martín-Lobo, Pilar; Vergara-Moragues, Esperanza

2016-01-01

The authors' aim was to analyze the relationship of eye movements, auditory perception, and phonemic awareness with the reading process. The instruments used were the King-Devick Test (saccade eye movements), the PAF test (auditory perception), the PFC (phonemic awareness), the PROLEC-R (lexical process), the Canals reading speed test, and the…

Children's Eye Movements, Miscue Analysis Patterns, and Retellings When Reading a Counterpoint Picture Book

ERIC Educational Resources Information Center

Liwanag, Maria Perpetua Socorro U.; Pelatti, Christina Yeager; Martens, Ray; Martens, Prisca

2016-01-01

This study incorporated eye movement miscue analysis to investigate two second-graders' oral reading and comprehension of a counterpoint picture book. Findings suggest the second-graders' strategies when reading the written and pictorial text affected their comprehension as opposed to the number and location of their eye movements. Specifically,…

Eye Movements during Scene Recollection Have a Functional Role, but They Are Not Reinstatements of Those Produced during Encoding

ERIC Educational Resources Information Center

Johansson, Roger; Holsanova, Jana; Dewhurst, Richard; Holmqvist, Kenneth

2012-01-01

Current debate in mental imagery research revolves around the perceptual and cognitive role of eye movements to "nothing" (Ferreira, Apel, & Henderson, 2008; Richardson, Altmann, Spivey, & Hoover, 2009). While it is established that eye movements are comparable when inspecting a scene (or hearing a scene description) as when…

Validity of Eye Movement Methods and Indices for Capturing Semantic (Associative) Priming Effects

ERIC Educational Resources Information Center

Odekar, Anshula; Hallowell, Brooke; Kruse, Hans; Moates, Danny; Lee, Chao-Yang

2009-01-01

Purpose: The purpose of this investigation was to evaluate the usefulness of eye movement methods and indices as a tool for studying priming effects by verifying whether eye movement indices capture semantic (associative) priming effects in a visual cross-format (written word to semantically related picture) priming paradigm. Method: In the…

Learning to See: Guiding Students' Attention via a Model's Eye Movements Fosters Learning

ERIC Educational Resources Information Center

Jarodzka, Halszka; van Gog, Tamara; Dorr, Michael; Scheiter, Katharina; Gerjets, Peter

2013-01-01

This study investigated how to teach perceptual tasks, that is, classifying fish locomotion, through eye movement modeling examples (EMME). EMME consisted of a replay of eye movements of a didactically behaving domain expert (model), which had been recorded while he executed the task, superimposed onto the video stimulus. Seventy-five students…

Eye Movements during Multiple Object Tracking: Where Do Participants Look?

ERIC Educational Resources Information Center

Fehd, Hilda M.; Seiffert, Adriane E.

2008-01-01

Similar to the eye movements you might make when viewing a sports game, this experiment investigated where participants tend to look while keeping track of multiple objects. While eye movements were recorded, participants tracked either 1 or 3 of 8 red dots that moved randomly within a square box on a black background. Results indicated that…

Individual Differences in Fifth Graders' Literacy and Academic Language Predict Comprehension Monitoring Development: An Eye-Movement Study

ERIC Educational Resources Information Center

Connor, Carol McDonald; Radach, Ralph; Vorstius, Christian; Day, Stephanie L.; McLean, Leigh; Morrison, Frederick J.

2015-01-01

In this study, we investigated fifth graders' (n = 52) fall literacy, academic language, and motivation and how these skills predicted fall and spring comprehension monitoring on an eye movement task. Comprehension monitoring was defined as the identification and repair of misunderstandings when reading text. In the eye movement task, children…

Exploring Cultural Variation in Eye Movements on a Web Page between Americans and Koreans

ERIC Educational Resources Information Center

Yang, Changwoo

2009-01-01

This study explored differences in eye movement on a Web page between members of two different cultures to provide insight and guidelines for implementation of global Web site development. More specifically, the research examines whether differences of eye movement exist between the two cultures (American vs. Korean) when viewing a Web page, and…

Secondary-Task Effects on Learning with Multimedia: An Investigation through Eye-Movement Analysis

ERIC Educational Resources Information Center

Acarturk, Cengiz; Ozcelik, Erol

2017-01-01

This study investigates secondary-task interference on eye movements through learning with multimedia. We focus on the relationship between the influence of the secondary task on the eye movements of learners, and the learning outcomes as measured by retention, matching, and transfer. Half of the participants performed a spatial tapping task while…

Initial Scene Representations Facilitate Eye Movement Guidance in Visual Search

ERIC Educational Resources Information Center

Castelhano, Monica S.; Henderson, John M.

2007-01-01

What role does the initial glimpse of a scene play in subsequent eye movement guidance? In 4 experiments, a brief scene preview was followed by object search through the scene via a small moving window that was tied to fixation position. Experiment 1 demonstrated that the scene preview resulted in more efficient eye movements compared with a…

Attention Switching during Scene Perception: How Goals Influence the Time Course of Eye Movements across Advertisements

ERIC Educational Resources Information Center

Wedel, Michel; Pieters, Rik; Liechty, John

2008-01-01

Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a…

Using Eye Movements to Model the Sequence of Text-Picture Processing for Multimedia Comprehension

ERIC Educational Resources Information Center

Mason, L.; Scheiter, K.; Tornatora, M. C.

2017-01-01

This study used eye movement modeling examples (EMME) to support students' integrative processing of verbal and graphical information during the reading of an illustrated text. EMME consists of a replay of eye movements of a model superimposed onto the materials that are processed for accomplishing the task. Specifically, the study investigated…

Pursuit Eye Movements

NASA Technical Reports Server (NTRS)

Krauzlis, Rich; Stone, Leland; Null, Cynthia H. (Technical Monitor)

1998-01-01

When viewing objects, primates use a combination of saccadic and pursuit eye movements to stabilize the retinal image of the object of regard within the high-acuity region near the fovea. Although these movements involve widespread regions of the nervous system, they mix seamlessly in normal behavior. Saccades are discrete movements that quickly direct the eyes toward a visual target, thereby translating the image of the target from an eccentric retinal location to the fovea. In contrast, pursuit is a continuous movement that slowly rotates the eyes to compensate for the motion of the visual target, minimizing the blur that can compromise visual acuity. While other mammalian species can generate smooth optokinetic eye movements - which track the motion of the entire visual surround - only primates can smoothly pursue a single small element within a complex visual scene, regardless of the motion elsewhere on the retina. This ability likely reflects the greater ability of primates to segment the visual scene, to identify individual visual objects, and to select a target of interest.

The effect of age and sex on facial mimicry: a three-dimensional study in healthy adults.

PubMed

Sforza, C; Mapelli, A; Galante, D; Moriconi, S; Ibba, T M; Ferraro, L; Ferrario, V F

2010-10-01

To assess sex- and age-related characteristics in standardized facial movements, 40 healthy adults (20 men, 20 women; aged 20-50 years) performed seven standardized facial movements (maximum smile; free smile; "surprise" with closed mouth; "surprise" with open mouth; eye closure; right- and left-side eye closures). The three-dimensional coordinates of 21 soft tissue facial landmarks were recorded by a motion analyser, their movements computed, and asymmetry indices calculated. Within each movement, total facial mobility was independent from sex and age (analysis of variance, p>0.05). Asymmetry indices of the eyes and mouth were similar in both sexes (p>0.05). Age significantly influenced eye and mouth asymmetries of the right-side eye closure, and eye asymmetry of the surprise movement. On average, the asymmetry indices of the symmetric movements were always lower than 8%, and most did not deviate from the expected value of 0 (Student's t). Larger asymmetries were found for the asymmetric eye closures (eyes, up to 50%, p<0.05; mouth, up to 30%, p<0.05 only in the 20-30-year-old subjects). In conclusion, sex and age had a limited influence on total facial motion and asymmetry in normal adult men and women. Copyright © 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Difference in Visual Processing Assessed by Eye Vergence Movements

PubMed Central

Solé Puig, Maria; Puigcerver, Laura; Aznar-Casanova, J. Antonio; Supèr, Hans

2013-01-01

Orienting visual attention is closely linked to the oculomotor system. For example, a shift of attention is usually followed by a saccadic eye movement and can be revealed by micro saccades. Recently we reported a novel role of another type of eye movement, namely eye vergence, in orienting visual attention. Shifts in visuospatial attention are characterized by the response modulation to a selected target. However, unlike (micro-) saccades, eye vergence movements do not carry spatial information (except for depth) and are thus not specific to a particular visual location. To further understand the role of eye vergence in visual attention, we tested subjects with different perceptual styles. Perceptual style refers to the characteristic way individuals perceive environmental stimuli, and is characterized by a spatial difference (local vs. global) in perceptual processing. We tested field independent (local; FI) and field dependent (global; FD) observers in a cue/no-cue task and a matching task. We found that FI observers responded faster and had stronger modulation in eye vergence in both tasks than FD subjects. The results may suggest that eye vergence modulation may relate to the trade-off between the size of spatial region covered by attention and the processing efficiency of sensory information. Alternatively, vergence modulation may have a role in the switch in cortical state to prepare the visual system for new incoming sensory information. In conclusion, vergence eye movements may be added to the growing list of functions of fixational eye movements in visual perception. However, further studies are needed to elucidate its role. PMID:24069140

Anticipatory Eye Movements in Interleaving Templates of Human Behavior

NASA Technical Reports Server (NTRS)

Matessa, Michael

2004-01-01

Performance modeling has been made easier by architectures which package psychological theory for reuse at useful levels of abstraction. CPM-GOMS uses templates of behavior to package at a task level (e.g., mouse move-click, typing) predictions of lower-level cognitive, perceptual, and motor resource use. CPM-GOMS also has a theory for interleaving resource use between templates. One example of interleaving is anticipatory eye movements. This paper describes the use of ACT-Stitch, a framework for translating CPM-GOMS templates and interleaving theory into ACT-R, to model anticipatory eye movements in skilled behavior. The anticipatory eye movements explain performance in a well-practiced perceptual/motor task, and the interleaving theory is supported with results from an eye-tracking experiment.

Measuring the effect of multiple eye fixations on memory for visual attributes.

PubMed

Palmer, J; Ames, C T

1992-09-01

Because of limited peripheral vision, many visual tasks depend on multiple eye fixations. Good performance in such tasks demonstrates that some memory must survive from one fixation to the next. One factor that must influence performance is the degree to which multiple eye fixations interfere with the critical memories. In the present study, the amount of interference was measured by comparing visual discriminations based on multiple fixations to visual discriminations based on a single fixation. The procedure resembled partial report, but used a discrimination measure. In the prototype study, two lines were presented, followed by a single line and a cue. The cue pointed toward one of the positions of the first two lines. Observers were required to judge if the single line in the second display was longer or shorter than the cued line of the first display. These judgments were used to estimate a length threshold. The critical manipulation was to instruct observers either to maintain fixation between the lines of the first display or to fixate each line in sequence. The results showed an advantage for multiple fixations despite the intervening eye movements. In fact, thresholds for the multiple-fixation condition were nearly as good as those in a control condition where the lines were foveally viewed without eye movements. Thus, eye movements had little or no interfering effect in this task. Additional studies generalized the procedure and the stimuli. In conclusion, information about a variety of size and shape attributes was remembered with essentially no interference across eye fixations.

Wernicke-Korsakoff syndrome

MedlinePlus

... cause leg tremor Vision changes such as abnormal eye movements (back and forth movements called nystagmus), double vision , ... may show damage to many nerve systems: Abnormal eye movement Decreased or abnormal reflexes Fast pulse (heart rate) ...

Implications of Lateral Cerebellum in Proactive Control of Saccades.

PubMed

Kunimatsu, Jun; Suzuki, Tomoki W; Tanaka, Masaki

2016-06-29

Although several lines of evidence establish the involvement of the medial and vestibular parts of the cerebellum in the adaptive control of eye movements, the role of the lateral hemisphere of the cerebellum in eye movements remains unclear. Ascending projections from the lateral cerebellum to the frontal and parietal association cortices via the thalamus are consistent with a role of these pathways in higher-order oculomotor control. In support of this, previous functional imaging studies and recent analyses in subjects with cerebellar lesions have indicated a role for the lateral cerebellum in volitional eye movements such as anti-saccades. To elucidate the underlying mechanisms, we recorded from single neurons in the dentate nucleus of the cerebellum in monkeys performing anti-saccade/pro-saccade tasks. We found that neurons in the posterior part of the dentate nucleus showed higher firing rates during the preparation of anti-saccades compared with pro-saccades. When the animals made erroneous saccades to the visual stimuli in the anti-saccade trials, the firing rate during the preparatory period decreased. Furthermore, local inactivation of the recording sites with muscimol moderately increased the proportion of error trials, while successful anti-saccades were more variable and often had shorter latency during inactivation. Thus, our results show that neuronal activity in the cerebellar dentate nucleus causally regulates anti-saccade performance. Neuronal signals from the lateral cerebellum to the frontal cortex might modulate the proactive control signals in the corticobasal ganglia circuitry that inhibit early reactive responses and possibly optimize the speed and accuracy of anti-saccades. Although the lateral cerebellum is interconnected with the cortical eye fields via the thalamus and the pons, its role in eye movements remains unclear. We found that neurons in the caudal part of the lateral (dentate) nucleus of the cerebellum showed the increased firing rate during the preparation of anti-saccades. Inactivation of the recording sites modestly elevated the rate of erroneous saccades to the visual stimuli in the anti-saccade trials, while successful anti-saccades during inactivation tended to have a shorter latency. Our data indicate that neuronal signals in the lateral cerebellum may proactively regulate anti-saccade generation through the pathways to the frontal cortex, and may inhibit early reactive responses and regulate the accuracy of anti-saccades. Copyright © 2016 the authors 0270-6474/16/367066-09$15.00/0.

Development and experimentation of an eye/brain/task testbed

NASA Technical Reports Server (NTRS)

Harrington, Nora; Villarreal, James

1987-01-01

The principal objective is to develop a laboratory testbed that will provide a unique capability to elicit, control, record, and analyze the relationship of operator task loading, operator eye movement, and operator brain wave data in a computer system environment. The ramifications of an integrated eye/brain monitor to the man machine interface are staggering. The success of such a system would benefit users of space and defense, paraplegics, and the monitoring of boring screens (nuclear power plants, air defense, etc.)

Microgravity

NASA Image and Video Library

2003-01-22

One concern about human adaptation to space is how returning from the microgravity of orbit to Earth can affect an astronaut's ability to fly safely. There are monitors and infrared video cameras to measure eye movements without having to affect the crew member. A computer screen provides moving images which the eye tracks while the brain determines what it is seeing. A video camera records movement of the subject's eyes. Researchers can then correlate perception and response. Test subjects perceive different images when a moving object is covered by a mask that is visible or invisible (above). Early results challenge the accepted theory that smooth pursuit -- the fluid eye movement that humans and primates have -- does not involve the higher brain. NASA results show that: Eye movement can predict human perceptual performance, smooth pursuit and saccadic (quick or ballistic) movement share some signal pathways, and common factors can make both smooth pursuit and visual perception produce errors in motor responses.

Understanding Visible Perception

NASA Technical Reports Server (NTRS)

2003-01-01

One concern about human adaptation to space is how returning from the microgravity of orbit to Earth can affect an astronaut's ability to fly safely. There are monitors and infrared video cameras to measure eye movements without having to affect the crew member. A computer screen provides moving images which the eye tracks while the brain determines what it is seeing. A video camera records movement of the subject's eyes. Researchers can then correlate perception and response. Test subjects perceive different images when a moving object is covered by a mask that is visible or invisible (above). Early results challenge the accepted theory that smooth pursuit -- the fluid eye movement that humans and primates have -- does not involve the higher brain. NASA results show that: Eye movement can predict human perceptual performance, smooth pursuit and saccadic (quick or ballistic) movement share some signal pathways, and common factors can make both smooth pursuit and visual perception produce errors in motor responses.

Understanding eye movements in face recognition using hidden Markov models.

PubMed

Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

2014-09-16

We use a hidden Markov model (HMM) based approach to analyze eye movement data in face recognition. HMMs are statistical models that are specialized in handling time-series data. We conducted a face recognition task with Asian participants, and model each participant's eye movement pattern with an HMM, which summarized the participant's scan paths in face recognition with both regions of interest and the transition probabilities among them. By clustering these HMMs, we showed that participants' eye movements could be categorized into holistic or analytic patterns, demonstrating significant individual differences even within the same culture. Participants with the analytic pattern had longer response times, but did not differ significantly in recognition accuracy from those with the holistic pattern. We also found that correct and wrong recognitions were associated with distinctive eye movement patterns; the difference between the two patterns lies in the transitions rather than locations of the fixations alone. © 2014 ARVO.

Is having similar eye movement patterns during face learning and recognition beneficial for recognition performance? Evidence from hidden Markov modeling.

PubMed

Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

2017-12-01

The hidden Markov model (HMM)-based approach for eye movement analysis is able to reflect individual differences in both spatial and temporal aspects of eye movements. Here we used this approach to understand the relationship between eye movements during face learning and recognition, and its association with recognition performance. We discovered holistic (i.e., mainly looking at the face center) and analytic (i.e., specifically looking at the two eyes in addition to the face center) patterns during both learning and recognition. Although for both learning and recognition, participants who adopted analytic patterns had better recognition performance than those with holistic patterns, a significant positive correlation between the likelihood of participants' patterns being classified as analytic and their recognition performance was only observed during recognition. Significantly more participants adopted holistic patterns during learning than recognition. Interestingly, about 40% of the participants used different patterns between learning and recognition, and among them 90% switched their patterns from holistic at learning to analytic at recognition. In contrast to the scan path theory, which posits that eye movements during learning have to be recapitulated during recognition for the recognition to be successful, participants who used the same or different patterns during learning and recognition did not differ in recognition performance. The similarity between their learning and recognition eye movement patterns also did not correlate with their recognition performance. These findings suggested that perceptuomotor memory elicited by eye movement patterns during learning does not play an important role in recognition. In contrast, the retrieval of diagnostic information for recognition, such as the eyes for face recognition, is a better predictor for recognition performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design and optimize of 3-axis filament winding machine

NASA Astrophysics Data System (ADS)

Quanjin, Ma; Rejab, M. R. M.; Idris, M. S.; Bachtiar, B.; Siregar, J. P.; Harith, M. N.

2017-10-01

Filament winding technique is developed as the primary process for composite cylindrical structures fabrication at low cost. Fibres are wound on a rotating mandrel by a filament winding machine where resin impregnated fibres pass through a pay-out eye. This paper aims to develop and optimize a 3-axis, lightweight, practical, efficient, portable filament winding machine to satisfy the customer demand, which can fabricate pipes and round shape cylinders with resins. There are 3 main units on the 3-axis filament winding machine, which are the rotary unit, the delivery unit and control system unit. Comparison with previous existing filament winding machines in the factory, it has 3 degrees of freedom and can fabricate more complex shape specimens based on the mandrel shape and particular control system. The machine has been designed and fabricated on 3 axes movements with control system. The x-axis is for movement of the carriage, the y-axis is the rotation of mandrel and the z-axis is the movement of the pay-out eye. Cylindrical specimens with different dimensions and winding angles were produced. 3-axis automated filament winding machine has been successfully designed with simple control system.

The role of peripheral vision in saccade planning: learning from people with tunnel vision.

PubMed

Luo, Gang; Vargas-Martin, Fernando; Peli, Eli

2008-12-22

Both visually salient and top-down information are important in eye movement control, but their relative roles in the planning of daily saccades are unclear. We investigated the effect of peripheral vision loss on saccadic behaviors in patients with tunnel vision (visual field diameters 7 degrees-16 degrees) in visual search and real-world walking experiments. The patients made up to two saccades per second to their pre-saccadic blind areas, about half of which had no overlap between the post- and pre-saccadic views. In the visual search experiment, visual field size and the background (blank or picture) did not affect the saccade sizes and direction of patients (n = 9). In the walking experiment, the patients (n = 5) and normal controls (n = 3) had similar distributions of saccade sizes and directions. These findings might provide a clue about the large extent of the top-down mechanism influence on eye movement control.