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Sample records for abnormal eye movements

  1. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem. PMID:22377853

  2. Abnormal Saccadic Eye Movements in Autistic Children.

    ERIC Educational Resources Information Center

    Kemner, C.; Verbaten, M. N.; Cuperus, J. M.; Camfferman, G.; van Engeland, H.

    1998-01-01

    The saccadic eye movements, generated during a visual oddball task, were compared for 10 autistic children, 10 children with attention deficit hyperactivity disorder, 10 dyslexic children, and 10 typically developing children. Several abnormal patterns of saccades were found in the autistic group. (DB)

  3. 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

  4. Eye movement abnormalities in anorexia nervosa.

    PubMed

    Pallanti, S; Quercioli, L; Zaccara, G; Ramacciotti, A B; Arnetoli, G

    1998-03-20

    The aim of the present study is to investigate smooth pursuit eye movement and saccadic performance in anorexia nervosa during a restored weight period and to determine if functional links can be made between eye movement performance and clinical features. SPEM parameters were recorded for 28 female anorectic out-patients (DSM IV), who had a body weight loss of up to 20% of ideal body weight. Twenty-eight comparison subjects were also tested. Clinically, each patient was assessed using the Eating Disorder Inventory (EDI), the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Structured Interview for Personality Disorders (SCID II), the Symptom Checklist-90-Revised (SCL-90-R) and the Hamilton Scale for Depression (HRSD). The anorectic patients performed slightly worse than the comparison subjects on a number of SPEM measures. No relationship was found between SPEM impairment and a global severity index of psychopathology (SCL 90-R GSI) or depressive symptoms. Moreover, OCD symptoms and scores on some EDI scales (such as perfectionism) appear related to the severity of the eye movement alterations. The evidence of SPEM abnormalities in a subgroup of anorectic patients during the remitted state and the relationship of the abnormalities to obsessive-compulsive symptoms are discussed. Results are in agreement with the hypothesis regarding the persistence of neurophysiological as well as psychopathological traits of disorder in anorectic patients. PMID:9579703

  5. Abnormal Eye Movements in Creutzfeldt-Jakob Disease

    NASA Technical Reports Server (NTRS)

    Grant, Michael P.; Cohen, Mark; Petersen, Robert B.; Halmagyi, G. Michael; McDougall, Alan; Tusa, Ronald J.; Leigh, R. John

    1993-01-01

    We report 3 patients with autopsy-proven Creutzfeldt-Jakob disease who, early in their course, developed abnormal eye movements that included periodic alternating nystagmus and slow vertical saccades. These findings suggested involvement of the cerebellar nodulus and uvula, and the brainstem reticular formation, respectively. Cerebellar ataxia was also an early manifestation and, in one patient, a frontal lobe brain biopsy was normal at a time when ocular motor and cerebellar signs were conspicuous. As the disease progressed, all saccades and quick phases of nystagmus were lost, but periodic alternating gaze deviation persisted. At autopsy, 2 of the 3 patients had pronounced involvement of the cerebellum, especially of the midline structures. Creutzfeldt-Jakob disease should be considered in patients with subacute progressive neurological disease when cognitive changes are overshadowed by ocular motor findings or ataxia.

  6. Unidirectional abnormal eye movement without gaze nystagmus - Report of a case.

    PubMed

    Mizuno, Masahiro; Shibasaki, Osamu; Shindo, Susumu; Ito, Akinori; Kase, Yasuhiro

    2016-06-01

    We report here a case with unidirectional abnormalities of smooth eye movements without gaze nystagmus. Abnormalities of eye movements were confined to unidirectional (leftward) horizontal pursuit and slow phase of OKN; however, horizontal VOR (slow phase of caloric nystagmus) and saccade were normal, and vertical eye movements were also normal. No lesions were detected in the central nervous system, and any history of drug intake was denied. Although the cause of the unidirectional abnormality in eye movement of this case is still not clear, a congenital origin seems to be the most probable. PMID:26386498

  7. Saccadic Eye Movement Abnormalities in Children with Epilepsy

    PubMed Central

    Lunn, Judith; Donovan, Tim; Litchfield, Damien; Lewis, Charlie; Davies, Robert; Crawford, Trevor

    2016-01-01

    Childhood onset epilepsy is associated with disrupted developmental integration of sensorimotor and cognitive functions that contribute to persistent neurobehavioural comorbidities. The role of epilepsy and its treatment on the development of functional integration of motor and cognitive domains is unclear. Oculomotor tasks can probe neurophysiological and neurocognitive mechanisms vulnerable to developmental disruptions by epilepsy-related factors. The study involved 26 patients and 48 typically developing children aged 8–18 years old who performed a prosaccade and an antisaccade task. Analyses compared medicated chronic epilepsy patients and unmedicated controlled epilepsy patients to healthy control children on saccade latency, accuracy and dynamics, errors and correction rate, and express saccades. Patients with medicated chronic epilepsy had impaired and more variable processing speed, reduced accuracy, increased peak velocity and a greater number of inhibitory errors, younger unmedicated patients also showed deficits in error monitoring. Deficits were related to reported behavioural problems in patients. Epilepsy factors were significant predictors of oculomotor functions. An earlier age at onset predicted reduced latency of prosaccades and increased express saccades, and the typical relationship between express saccades and inhibitory errors was absent in chronic patients, indicating a persistent reduction in tonic cortical inhibition and aberrant cortical connectivity. In contrast, onset in later childhood predicted altered antisaccade dynamics indicating disrupted neurotransmission in frontoparietal and oculomotor networks with greater demand on inhibitory control. The observed saccadic abnormalities are consistent with a dysmaturation of subcortical-cortical functional connectivity and aberrant neurotransmission. Eye movements could be used to monitor the impact of epilepsy on neurocognitive development and help assess the risk for poor neurobehavioural

  8. Saccadic Eye Movement Abnormalities in Children with Epilepsy.

    PubMed

    Lunn, Judith; Donovan, Tim; Litchfield, Damien; Lewis, Charlie; Davies, Robert; Crawford, Trevor

    2016-01-01

    Childhood onset epilepsy is associated with disrupted developmental integration of sensorimotor and cognitive functions that contribute to persistent neurobehavioural comorbidities. The role of epilepsy and its treatment on the development of functional integration of motor and cognitive domains is unclear. Oculomotor tasks can probe neurophysiological and neurocognitive mechanisms vulnerable to developmental disruptions by epilepsy-related factors. The study involved 26 patients and 48 typically developing children aged 8-18 years old who performed a prosaccade and an antisaccade task. Analyses compared medicated chronic epilepsy patients and unmedicated controlled epilepsy patients to healthy control children on saccade latency, accuracy and dynamics, errors and correction rate, and express saccades. Patients with medicated chronic epilepsy had impaired and more variable processing speed, reduced accuracy, increased peak velocity and a greater number of inhibitory errors, younger unmedicated patients also showed deficits in error monitoring. Deficits were related to reported behavioural problems in patients. Epilepsy factors were significant predictors of oculomotor functions. An earlier age at onset predicted reduced latency of prosaccades and increased express saccades, and the typical relationship between express saccades and inhibitory errors was absent in chronic patients, indicating a persistent reduction in tonic cortical inhibition and aberrant cortical connectivity. In contrast, onset in later childhood predicted altered antisaccade dynamics indicating disrupted neurotransmission in frontoparietal and oculomotor networks with greater demand on inhibitory control. The observed saccadic abnormalities are consistent with a dysmaturation of subcortical-cortical functional connectivity and aberrant neurotransmission. Eye movements could be used to monitor the impact of epilepsy on neurocognitive development and help assess the risk for poor neurobehavioural

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

    PubMed Central

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

    2014-01-01

    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. PMID:25338949

  10. An Investigation of Horizontal Combined Eye-Head Tracking in Patients with Abnormal Vestibular and Smooth Pursuit Eye Movements

    NASA Technical Reports Server (NTRS)

    Huebner, William P.; Leigh, R. John; Seidman, Scott H.; Billian, Carl

    1993-01-01

    We investigated the interaction of smooth ocular pursuit (SP) and the vestibulo-ocular reflex (VOR) during horizontal, combined eye-head tracking (CEHT) in patients with abnormalities of either the VOR or SP movements. Our strategy was to apply transient stimuli that capitalized on the different latencies to onset of SP and the VOR. During CEHT of a target moving at 15 deg/sec, normal subjects and patients with VOR deficits all tracked the target with a gain close to 1.O. When the heads of normal subjects were suddenly and unexpectedly braked to a halt during CEHT, the eye promptly began to move in the orbit to track the target, but eye-in-orbit velocity transiently fell to about 60-70% of target velocity. In patients with deficient labyrinthine function, following the onset of the head brake, eye movements to track the target were absent, and SP movements were not generated until about 100 msec later. In patients with deficient SP, CEHT was superior to SP tracking with the head stationary; after the onset of the head brake, tracking eye movements were initiated promptly, but eye velocity was less than 50% of target velocity and increased only slightly thereafter. These results indicate that at least two mechanisms operate to overcome the VOR and allow gaze to track the target during CEHT: (1) the SP system provides a signal to cancel a normally-operating VOR (this cancellation signal is not needed by labyrinthine-deficient patients who have no VOR to cancel), and (2) a reduction of the gain of the VOR is achieved, an ability that is preserved even in patients with cerebral lesions that impair SP.

  11. Subtle rapid eye movement sleep abnormalities in presymptomatic spinocerebellar ataxia type 2 gene carriers.

    PubMed

    Rodríguez-Labrada, Roberto; Velázquez-Perez, Luis; Ochoa, Nalia Canales; Polo, Lourdes Galicia; Valencia, Reyes Haro; Cruz, Gilberto Sánchez; Montero, Jacqueline Medrano; Laffita-Mesa, José M; Mederos, Luis E Almaguer; Zaldívar, Yanetza González; Parra, Cira Torres; Acosta, Arnoy Peña; Mariño, Tania Cruz

    2011-02-01

    Rapid eye movement (REM) sleep disorders are commonly associated to patients with spinocerebellar ataxia type 2 (SCA2); however, these abnormalities have not been studied in presymptomatic gene carriers. To determine whether the REM sleep pathology is detectable before clinical manifestation of SCA2 and evaluate it as a preclinical biomarker, we studied 36 presymptomatic SCA2 individuals and 36 controls by video-polysomnography (VPSG) and sleep questionnaires. Presymptomatic subjects showed significant decrease of REM sleep percentage, REMs density, total sleep time, and sleep efficiency. Aging effect on REM sleep percentage was significant in both groups. There was no correlation between cytosine-adenine-guanine (CAG) repeat length and REM sleep. Our findings identified the REM sleep pathology as a prominent herald sign of SCA2, conferring a special importance to VPSG as a sensitive neurophysiological tool to detect early changes associated with SCA2, which contributes to the understanding of disease pathophysiology and the development of therapeutic trials focused on the preclinical disease stage. PMID:20960485

  12. 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 ...

  13. Elevated PEM (Phasic Electromyographic Metric) Rates Identify Rapid Eye Movement Behavior Disorder Patients on Nights Without Behavioral Abnormalities

    PubMed Central

    Bliwise, Donald L.; Rye, David B.

    2008-01-01

    Objective: To determine the validity of the phasic electromyographic metric (PEM) to differentiate patients with a history suggestive of rapid eye movement behavior disorder (REMBD) on laboratory nights without overt dream-enactment behavior. Methods: PEM was quantified as the % of 2.5-sec intervals with phasic muscle activity of 100-msec duration with an amplitude of at least 4 times background activity in 11 patients and 31 elderly controls. Data were derived from both REM and NREM sleep from 5 muscle groups (mentalis, left/right anterior tibialis, left/right brachioradialis). Results: Relative to controls, REMBD patients had significantly higher levels of PEM activity in all recordings. The largest differences occurred during REM sleep for the mentalis and brachioradialis channels. Similar results were obtained by limiting quantification of PEM to the final REM period of the night and could be accomplished by individuals with no previous familiarity with polysomnography. Discussion: PEM may be a useful metric to characterize the REM related phasic muscle activity on patients with a history of REMBD, even when no overt dream-enactment behaviors are detected on a laboratory night. Citation: Bliwise DL; Rye DB. Elevated PEM (phasic electromyographic metric) rates identify rapid eye movement behavior disorder patients on nights without behavioral abnormalities. SLEEP 2008;31(6):853–857. PMID:18548830

  14. Paraneoplastic disorders of eye movements

    PubMed Central

    Wray, Shirley H.; Dalmau, Josep; Chen, Athena; King, Susan; Leigh, R. John

    2011-01-01

    Paraneoplastic syndromes affecting the brainstem and cerebellum are reported to cause a variety of abnormalities of eye movements. Recent studies have begun to account for the mechanisms underlying several syndromes, characterized by opsoclonus, slow, or dysmetric saccades, as well as downbeat nystagmus. We provide evidence that upbeat nystagmus in a patient with pancreatic cancer reflected a cerebellar-induced imbalance of otolithic pathways: she showed marked retropulsion, and her nystagmus was dependent on head position, being absent when supine, and suppressed with convergence. In addition to anti-Hu antibodies, we demonstrated antibodies to a novel neuronal cell surface antigen. Taken with other recent studies, our findings suggest that paraneoplastic syndromes arise due to antibodies against surface neuronal antigens, including receptors and channels. Abnormal eye movements in paraneoplastic syndromes offer insights into the pathogenesis of these disorders and the opportunity to test potential therapies, such as new drugs with effects on neuronal channels. PMID:21951005

  15. 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.

  16. 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

  17. Arousal facilitates involuntary eye movements.

    PubMed

    DiGirolamo, Gregory J; Patel, Neha; Blaukopf, Clare L

    2016-07-01

    Attention plays a critical role in action selection. However, the role of attention in eye movements is complicated as these movements can be either voluntary or involuntary, with, in some circumstances (antisaccades), these two actions competing with each other for execution. But attending to the location of an impending eye movement is only one facet of attention that may play a role in eye movement selection. In two experiments, we investigated the effect of arousal on voluntary eye movements (antisaccades) and involuntary eye movements (prosaccadic errors) in an antisaccade task. Arousal, as caused by brief loud sounds and indexed by changes in pupil diameter, had a facilitation effect on involuntary eye movements. Involuntary eye movements were both significantly more likely to be executed and significantly faster under arousal conditions (Experiments 1 and 2), and the influence of arousal had a specific time course (Experiment 2). Arousal, one form of attention, can produce significant costs for human movement selection as potent but unplanned actions are benefited more than planned ones. PMID:26928432

  18. 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

  19. Eye movements when viewing advertisements.

    PubMed

    Higgins, Emily; Leinenger, Mallorie; Rayner, Keith

    2014-01-01

    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

  20. 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

  1. How Were Eye Movements Recorded Before Yarbus?

    PubMed

    Wade, Nicholas J

    2015-01-01

    Alfred Yarbus introduced a new dimension of precision in recording how the eyes moved, either when attempts were made to keep them stationary or when scanning pictures. Movements of the eyes had been remarked upon for millennia, but recording how they move is a more recent preoccupation. Emphasis was initially placed on abnormalities of oculomotor function (like strabismus) before normal features were considered. The interest was in where the eyes moved to rather than determining how they got there. The most venerable technique for examining ocular stability involved comparing the relative motion between an afterimage and a real image. In the late 18th century, Wells compared afterimages generated before body rotation with real images observed following it when dizzy; he described both lateral and torsional nystagmus, thereby demonstrating the directional discontinuities in eye velocities. At around the same time Erasmus Darwin used afterimages as a means of demonstrating ocular instability when attempting to fixate steadily. However, the overriding concern in the 19th century was with eye position rather than eye movements. Thus, the characteristics of nystagmus were recorded before those of saccades and fixations. Eye movements during reading were described by Hering and by Lamare (working in Javal's laboratory) in 1879; both used similar techniques of listening (with tubes placed over the eyelids) to the 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. Eye movements over pictures were examined by Stratton and later by Buswell, who drew attention to the effects of instructions on the pattern of eye movements. In midcentury, attention shifted back to the stability of the eyes during fixation, with the emphasis on involuntary movements. The suction cap methods developed by Yarbus were applied

  2. Eye Movements, Perceptual Span, and Reading Disability.

    ERIC Educational Resources Information Center

    Rayner, Keith

    1983-01-01

    Research is reviewed on eye movements during reading, on the perceptual span and control of eye movements during normal reading, and on the nature of eye movements in dyslexia. Rather than the cause of dyslexia, eye movements are said to reflect underlying cognitive or neurological problems. (CL)

  3. Yarbus, eye movements, and vision

    PubMed Central

    Tatler, Benjamin W; Wade, Nicholas J; Kwan, Hoi; Findlay, John M; Velichkovsky, Boris M

    2010-01-01

    The impact of Yarbus's research on eye movements was enormous following the translation of his book Eye Movements and Vision into English in 1967. In stark contrast, the published material in English concerning his life is scant. We provide a brief biography of Yarbus and assess his impact on contemporary approaches to research on eye movements. While early interest in his work focused on his study of stabilised retinal images, more recently this has been replaced with interest in his work on the cognitive influences on scanning patterns. We extended his experiment on the effect of instructions on viewing a picture using a portrait of Yarbus rather than a painting. The results obtained broadly supported those found by Yarbus. PMID:23396904

  4. Eye Movement Disorders in Dyslexia. Final Report.

    ERIC Educational Resources Information Center

    Festinger, Leon; And Others

    Eye movements of 18 male and seven female dyslexic children and 10 normal children were evaluated to determine if eye movement disorders may be the cause of some of the symptoms associated with dyslexia. Data on eye movements were collected while Ss moved their eyes from one fixation point to another in a nonreading situation. Errors in vertical…

  5. Eye movements reset visual perception

    PubMed Central

    Paradiso, Michael A.; Meshi, Dar; Pisarcik, Jordan; Levine, Samuel

    2012-01-01

    Human vision uses saccadic eye movements to rapidly shift the sensitive foveal portion of our retina to objects of interest. For vision to function properly amidst these ballistic eye movements, a mechanism is needed to extract discrete percepts on each fixation from the continuous stream of neural activity that spans fixations. The speed of visual parsing is crucial because human behaviors ranging from reading to driving to sports rely on rapid visual analysis. We find that a brain signal associated with moving the eyes appears to play a role in resetting visual analysis on each fixation, a process that may aid in parsing the neural signal. We quantified the degree to which the perception of tilt is influenced by the tilt of a stimulus on a preceding fixation. Two key conditions were compared, one in which a saccade moved the eyes from one stimulus to the next and a second simulated saccade condition in which the stimuli moved in the same manner but the subjects did not move their eyes. We find that there is a brief period of time at the start of each fixation during which the tilt of the previous stimulus influences perception (in a direction opposite to the tilt aftereffect)—perception is not instantaneously reset when a fixation starts. Importantly, the results show that this perceptual bias is much greater, with nearly identical visual input, when saccades are simulated. This finding suggests that, in real-saccade conditions, some signal related to the eye movement may be involved in the reset phenomenon. While proprioceptive information from the extraocular muscles is conceivably a factor, the fast speed of the effect we observe suggests that a more likely mechanism is a corollary discharge signal associated with eye movement. PMID:23241264

  6. Eye movements reset visual perception.

    PubMed

    Paradiso, Michael A; Meshi, Dar; Pisarcik, Jordan; Levine, Samuel

    2012-01-01

    Human vision uses saccadic eye movements to rapidly shift the sensitive foveal portion of our retina to objects of interest. For vision to function properly amidst these ballistic eye movements, a mechanism is needed to extract discrete percepts on each fixation from the continuous stream of neural activity that spans fixations. The speed of visual parsing is crucial because human behaviors ranging from reading to driving to sports rely on rapid visual analysis. We find that a brain signal associated with moving the eyes appears to play a role in resetting visual analysis on each fixation, a process that may aid in parsing the neural signal. We quantified the degree to which the perception of tilt is influenced by the tilt of a stimulus on a preceding fixation. Two key conditions were compared, one in which a saccade moved the eyes from one stimulus to the next and a second simulated saccade condition in which the stimuli moved in the same manner but the subjects did not move their eyes. We find that there is a brief period of time at the start of each fixation during which the tilt of the previous stimulus influences perception (in a direction opposite to the tilt aftereffect)--perception is not instantaneously reset when a fixation starts. Importantly, the results show that this perceptual bias is much greater, with nearly identical visual input, when saccades are simulated. This finding suggests that, in real-saccade conditions, some signal related to the eye movement may be involved in the reset phenomenon. While proprioceptive information from the extraocular muscles is conceivably a factor, the fast speed of the effect we observe suggests that a more likely mechanism is a corollary discharge signal associated with eye movement. PMID:23241264

  7. 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.

  8. Eye Movements during Chinese Reading

    ERIC Educational Resources Information Center

    Liversedge, Simon P; Hyona, Jukka; Rayner, Keith

    2013-01-01

    respects, and for this reason, interest in the nature of the cognitive processes underlying Chinese reading has flourished over recent years. A number of researchers have used eye movement methodology as a measure of on-line processing to understand more about…

  9. 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. PMID:12929791

  10. Eye movements and information geometry.

    PubMed

    Lenz, Reiner

    2016-08-01

    The human visual system uses eye movements to gather visual information. They act as visual scanning processes and can roughly be divided into two different types: small movements around fixation points and larger movements between fixation points. The processes are often modeled as random walks, and recent models based on heavy tail distributions, also known as Levý flights, have been used in these investigations. In contrast to these approaches we do not model the stochastic processes, but we will show that the step lengths of the movements between fixation points follow generalized Pareto distributions (GPDs). We will use general arguments from the theory of extreme value statistics to motivate the usage of the GPD and show empirically that the GPDs provide good fits for measured eye tracking data. In the framework of information geometry the GPDs with a common threshold form a two-dimensional Riemann manifold with the Fisher information matrix as a metric. We compute the Fisher information matrix for the GPDs and introduce a feature vector describing a GPD by its parameters and different geometrical properties of its Fisher information matrix. In our statistical analysis we use eye tracker measurements in a database with 15 observers viewing 1003 images under free-viewing conditions. We use Matlab functions with their standard parameter settings and show that a naive Bayes classifier using the eigenvalues of the Fisher information matrix provides a high classification rate identifying the 15 observers in the database. PMID:27505658

  11. Saccadic eye movement during spaceflight

    NASA Technical Reports Server (NTRS)

    Uri, John J.; Linder, Barry J.; Moore, Thomas P.; Pool, Sam L.; Thornton, William E.

    1989-01-01

    Saccadic eye movements were studied in six subjects during two Space Shuttle missions. Reaction time, peak velocity and accuracy of horizontal, visually-guided saccades were examined preflight, inflight and postflight. Conventional electro-oculography was used to record eye position, with the subjects responding to pseudo-randomly illuminated targets at 0 deg and + or - 10 deg and 20 deg visual angles. In all subjects, preflight measurements were within normal limits. Reaction time was significantly increased inflight, while peak velocity was significantly decreased. A tendency toward a greater proportion of hypometric saccades inflight was also noted. Possible explanations for these changes and possible correlations with space motion sickness are discussed.

  12. Alterations of eye movement control in neurodegenerative movement disorders.

    PubMed

    Gorges, Martin; Pinkhardt, Elmar H; Kassubek, Jan

    2014-01-01

    The evolution of the fovea centralis, the most central part of the retina and the area of the highest visual accuracy, requires humans to shift their gaze rapidly (saccades) to bring some object of interest within the visual field onto the fovea. In addition, humans are equipped with the ability to rotate the eye ball continuously in a highly predicting manner (smooth pursuit) to hold a moving target steadily upon the retina. The functional deficits in neurodegenerative movement disorders (e.g., Parkinsonian syndromes) involve the basal ganglia that are critical in all aspects of movement control. Moreover, neocortical structures, the cerebellum, and the midbrain may become affected by the pathological process. A broad spectrum of eye movement alterations may result, comprising smooth pursuit disturbance (e.g., interrupting saccades), saccadic dysfunction (e.g., hypometric saccades), and abnormal attempted fixation (e.g., pathological nystagmus and square wave jerks). On clinical grounds, videooculography is a sensitive noninvasive in vivo technique to classify oculomotion function alterations. Eye movements are a valuable window into the integrity of central nervous system structures and their changes in defined neurodegenerative conditions, that is, the oculomotor nuclei in the brainstem together with their directly activating supranuclear centers and the basal ganglia as well as cortical areas of higher cognitive control of attention. PMID:24955249

  13. OrbitView: Eye movement visualization software

    PubMed Central

    Hong, Simon; Optican, Lance M.; FitzGibbon, Edmond J.; Zee, David S.; Shaikh, Aasef G.

    2011-01-01

    Measurement of eye movements often helps to diagnose ocular motor disorders in the clinic, and is also used as a research tool in ocular motor, vision and vestibular research. Eye movements, however, are usually recorded without simultaneous video recordings, making offline interpretation difficult. We developed a tool that converts the measured eye movement data into a three-dimensional (3D) movie of eye movements. Having useful functions such as slow-play, pause and exaggeration of the movements, this new software provides a research and teaching tool to aid interpretation of the recorded eye movements. PMID:21689683

  14. Aspectual coercion in eye movements.

    PubMed

    Townsend, David J

    2013-06-01

    Comprehension includes interpreting sentences in terms of aspectual categories such as processes (Harry climbed) and culminations (Harry reached the top). Adding a verbal modifier such as for many years to a culmination coerces its interpretation from one to many culminations. Previous studies have found that coercion increases lexical decision and meaning judgment time, but not eye fixation time. This study recorded eye movements as participants read sentences in which a coercive adverb increased the interpretation of multiple events. Adverbs appeared at the end of a clause and line; the post-adverb region appeared at the beginning of the next line; follow-up questions occasionally asked about aspectual meaning; and clause type varied systematically. Coercive adverbs increased eye fixation time in the post-adverb region and in the adverb and post-adverb regions combined. Factors that influence the appearance of aspectual coercion may include world knowledge, follow-up questions, and the location and ambiguity of adverbs. PMID:22492206

  15. 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)

  16. Eye Movements During Action Observation

    PubMed Central

    Gredebäck, Gustaf; Falck-Ytter, Terje

    2015-01-01

    An important element in social interactions is predicting the goals of others, including the goals of others’ manual actions. Over a decade ago, Flanagan and Johansson demonstrated that, when observing other people reaching for objects, the observer’s gaze arrives at the goal before the action is completed. Moreover, those authors proposed that this behavior was mediated by an embodied process, which takes advantage of the observer’s motor knowledge. Here, we scrutinize work that has followed that seminal article. We include studies on adults that have used combined eye tracking and transcranial magnetic stimulation technologies to test causal hypotheses about underlying brain circuits. We also include developmental studies on human infants. We conclude that, although several aspects of the embodied process of predictive eye movements remain to be clarified, current evidence strongly suggests that the motor system plays a causal role in guiding predictive gaze shifts that focus on another person’s future goal. The early emergence of the predictive gaze in infant development underlines its importance for social cognition and interaction. PMID:26385998

  17. Task Effects on Eye Movements during Reading

    ERIC Educational Resources Information Center

    Kaakinen, Johanna K.; Hyona, Jukka

    2010-01-01

    The present study examined how proofreading and reading-for-comprehension instructions influence eye movements during reading. Thirty-seven participants silently read sentences containing compound words as target words while their eye movements were being recorded. We manipulated word length and frequency to examine how task instructions influence…

  18. Eye Movement Patterns of Captioned Television Viewers.

    ERIC Educational Resources Information Center

    Jensema, Carl J.; Sharkawy, Sameh El; Danturthi, Ramalinga Sarma; Burch, Robert; Hsu, David

    2000-01-01

    Eye movement of six subjects (three with deafness) was recorded as they watched video segments with and without captions. The addition of captions to a video resulted in major changes in eye movement patterns, with the viewing process becoming primarily a reading process. (Contains six references.) (Author/CR)

  19. Eye Movement Analysis of Second Grade Children.

    ERIC Educational Resources Information Center

    Hankins, Huana; Thompson, Richard A.

    An investigation was undertaken to measure objectively children's eye movements to determine whether the effect of fatigue of the average school day decreases eye movement efficiency, suggesting that children might benefit more from reading instruction in the morning than in the afternoon. Using a photoelectric instrument designed to graph eye…

  20. Eccentric head positions reveal disorders of conjugate eye movement.

    PubMed Central

    Gresty, M

    1977-01-01

    The effect of head position on conjugate horizontal gaze was studied in healthy adults, in patients with multiple sclerosis without eye movement signs, and in patients with downbeat nystagmus indicative of low brain stem lesions. Displacements of gaze from primary position to 30 degrees left and right were recorded using the electro-oculogram, with the head in the primary position, and turned voluntarily to the left and right (in yaw). The quality of eye movements was noted and peak velocities of saccades were measured. The head turning test trebled the incidence of abnormal eye movements found in the multiple sclerosis patients and increased it by tenfold in the patients with downbeat nystagmus. Disorders of eye movement were also found in approximately 20--30% of healthy subjects tested. Weakness of abduction was the most common eye movement defect and appeared to be posterior internuclear ophthalmoplegia. A hypothesis is made which unifies the theoretical explanations of anterior and posterior internuclear ophthalmoplegia. The most likely cause of the disorders of eye movement observed is vertebrobasilar ischaemia induced by stretching and compression of the vertebral arteries during eccentric head posture. Images PMID:591979

  1. Eye Movements in Strategic Choice

    PubMed Central

    Gächter, Simon; Noguchi, Takao; Mullett, Timothy L.

    2015-01-01

    Abstract In risky and other multiattribute choices, the process of choosing is well described by random walk or drift diffusion models in which evidence is accumulated over time to threshold. In strategic choices, level‐k and cognitive hierarchy models have been offered as accounts of the choice process, in which people simulate the choice processes of their opponents or partners. We recorded the eye movements in 2 × 2 symmetric games including dominance‐solvable games like prisoner's dilemma and asymmetric coordination games like stag hunt and hawk–dove. The evidence was most consistent with the accumulation of payoff differences over time: we found longer duration choices with more fixations when payoffs differences were more finely balanced, an emerging bias to gaze more at the payoffs for the action ultimately chosen, and that a simple count of transitions between payoffs—whether or not the comparison is strategically informative—was strongly associated with the final choice. The accumulator models do account for these strategic choice process measures, but the level‐k and cognitive hierarchy models do not. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd.

  2. Brain-machine interface for eye movements.

    PubMed

    Graf, Arnulf B A; Andersen, Richard A

    2014-12-01

    A number of studies in tetraplegic humans and healthy nonhuman primates (NHPs) have shown that neuronal activity from reach-related cortical areas can be used to predict reach intentions using brain-machine interfaces (BMIs) and therefore assist tetraplegic patients by controlling external devices (e.g., robotic limbs and computer cursors). However, to our knowledge, there have been no studies that have applied BMIs to eye movement areas to decode intended eye movements. In this study, we recorded the activity from populations of neurons from the lateral intraparietal area (LIP), a cortical node in the NHP saccade system. Eye movement plans were predicted in real time using Bayesian inference from small ensembles of LIP neurons without the animal making an eye movement. Learning, defined as an increase in the prediction accuracy, occurred at the level of neuronal ensembles, particularly for difficult predictions. Population learning had two components: an update of the parameters of the BMI based on its history and a change in the responses of individual neurons. These results provide strong evidence that the responses of neuronal ensembles can be shaped with respect to a cost function, here the prediction accuracy of the BMI. Furthermore, eye movement plans could be decoded without the animals emitting any actual eye movements and could be used to control the position of a cursor on a computer screen. These findings show that BMIs for eye movements are promising aids for assisting paralyzed patients. PMID:25422454

  3. Evaluating camouflage design using eye movement data.

    PubMed

    Lin, Chiuhsiang Joe; Chang, Chi-Chan; Lee, Yung-Hui

    2014-05-01

    This study investigates the characteristics of eye movements during a camouflaged target search task. Camouflaged targets were randomly presented on two natural landscapes. The performance of each camouflage design was assessed by target detection hit rate, detection time, number of fixations on display, first saccade amplitude to target, number of fixations on target, fixation duration on target, and subjective ratings of search task difficulty. The results showed that the camouflage patterns could significantly affect the eye-movement behavior, especially first saccade amplitude and fixation duration, and the findings could be used to increase the sensitivity of the camouflage assessment. We hypothesized that the assessment could be made with regard to the differences in detectability and discriminability of the camouflage patterns. These could explain less efficient search behavior in eye movements. Overall, data obtained from eye movements can be used to significantly enhance the interpretation of the effects of different camouflage design. PMID:24139724

  4. Kinematics of Visually-Guided Eye Movements

    PubMed Central

    Hess, Bernhard J. M.; Thomassen, Jakob S.

    2014-01-01

    One of the hallmarks of an eye movement that follows Listing’s law is the half-angle rule that says that the angular velocity of the eye tilts by half the angle of eccentricity of the line of sight relative to primary eye position. Since all visually-guided eye movements in the regime of far viewing follow Listing’s law (with the head still and upright), the question about its origin is of considerable importance. Here, we provide theoretical and experimental evidence that Listing’s law results from a unique motor strategy that allows minimizing ocular torsion while smoothly tracking objects of interest along any path in visual space. The strategy consists in compounding conventional ocular rotations in meridian planes, that is in horizontal, vertical and oblique directions (which are all torsion-free) with small linear displacements of the eye in the frontal plane. Such compound rotation-displacements of the eye can explain the kinematic paradox that the fixation point may rotate in one plane while the eye rotates in other planes. Its unique signature is the half-angle law in the position domain, which means that the rotation plane of the eye tilts by half-the angle of gaze eccentricity. We show that this law does not readily generalize to the velocity domain of visually-guided eye movements because the angular eye velocity is the sum of two terms, one associated with rotations in meridian planes and one associated with displacements of the eye in the frontal plane. While the first term does not depend on eye position the second term does depend on eye position. We show that compounded rotation - displacements perfectly predict the average smooth kinematics of the eye during steady- state pursuit in both the position and velocity domain. PMID:24751602

  5. Kinematics of visually-guided eye movements.

    PubMed

    Hess, Bernhard J M; Thomassen, Jakob S

    2014-01-01

    One of the hallmarks of an eye movement that follows Listing's law is the half-angle rule that says that the angular velocity of the eye tilts by half the angle of eccentricity of the line of sight relative to primary eye position. Since all visually-guided eye movements in the regime of far viewing follow Listing's law (with the head still and upright), the question about its origin is of considerable importance. Here, we provide theoretical and experimental evidence that Listing's law results from a unique motor strategy that allows minimizing ocular torsion while smoothly tracking objects of interest along any path in visual space. The strategy consists in compounding conventional ocular rotations in meridian planes, that is in horizontal, vertical and oblique directions (which are all torsion-free) with small linear displacements of the eye in the frontal plane. Such compound rotation-displacements of the eye can explain the kinematic paradox that the fixation point may rotate in one plane while the eye rotates in other planes. Its unique signature is the half-angle law in the position domain, which means that the rotation plane of the eye tilts by half-the angle of gaze eccentricity. We show that this law does not readily generalize to the velocity domain of visually-guided eye movements because the angular eye velocity is the sum of two terms, one associated with rotations in meridian planes and one associated with displacements of the eye in the frontal plane. While the first term does not depend on eye position the second term does depend on eye position. We show that compounded rotation - displacements perfectly predict the average smooth kinematics of the eye during steady- state pursuit in both the position and velocity domain. PMID:24751602

  6. Fractal property of eye movements in schizophrenia.

    PubMed

    Yokoyama, H; Niwa, S; Itoh, K; Mazuka, R

    1996-08-01

    On the basis of a temporal model of animal behavior we conducted temporal analysis of eye movements in schizophrenic subjects (n = 10) and normal controls (n = 10). We found a fractal property in schizophrenic subjects, the fixation time of eye movement during reading ambiguous and difficult sentences showing a clear inverse power law distribution. An exponential distribution of a nonfractal nature was found in normal controls. PMID:8855352

  7. Review of rapid eye movement behavior sleep disorders.

    PubMed

    Abad, Vivien C; Guilleminault, Christian

    2004-03-01

    The spectrum of rapid eye movement behavior disorders (RBD) spans various age groups, with the greatest prevalence in elderly men. Major diagnostic features include harmful or potentially harmful sleep behaviors that disrupt sleep continuity and dream enactment during rapid eye movement sleep. In RBD patients, the polysomnogram during rapid eye movement sleep demonstrates excessive augmentation of chin electromyogram or excessive chin or limb phasic electromyogram twitching. RBD may be associated with various neurodegenerative disorders, such as multiple system atrophy, Parkinson's disease, and dementia with Lewy bodies. Other co-morbid conditions may include narcolepsy, agrypnia excitata, sleepwalking, and sleep terrors. RBD is hypothesized to be caused by primary dysfunction of the pedunculo-pontine nucleus or other key brainstem structures associated with basal ganglia pathology or, alternatively, from abnormal afferent signals in the basal ganglia leading to dysfunction in the midbrain extrapyramidal area/ pedunculo-pontine nucleus regions. PMID:14984689

  8. Distractor Interference during Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Spering, Miriam; Gegenfurtner, Karl R.; Kerzel, Dirk

    2006-01-01

    When 2 targets for pursuit eye movements move in different directions, the eye velocity follows the vector average (S. G. Lisberger & V. P. Ferrera, 1997). The present study investigates the mechanisms of target selection when observers are instructed to follow a predefined horizontal target and to ignore a moving distractor stimulus. Results show…

  9. 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.

  10. 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

  11. Temporal eye movement strategies during naturalistic viewing.

    PubMed

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

    2012-01-01

    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 while they viewed naturalistic movies. 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

  12. Manual tracking enhances smooth pursuit eye movements

    PubMed Central

    Niehorster, Diederick C.; Siu, Wilfred W. F.; Li, Li

    2015-01-01

    Previous studies have reported that concurrent manual tracking enhances smooth pursuit eye movements only when tracking a self-driven or a predictable moving target. Here, we used a control-theoretic approach to examine whether concurrent manual tracking enhances smooth pursuit of an unpredictable moving target. In the eye-hand tracking condition, participants used their eyes to track a Gaussian target that moved randomly along a horizontal axis. In the meantime, they used their dominant hand to move a mouse to control the horizontal movement of a Gaussian cursor to vertically align it with the target. In the eye-alone tracking condition, the target and cursor positions recorded in the eye-hand tracking condition were replayed, and participants only performed eye tracking of the target. Catch-up saccades were identified and removed from the recorded eye movements, allowing for a frequency-response analysis of the smooth pursuit response to unpredictable target motion. We found that the overall smooth pursuit gain was higher and the number of catch-up saccades made was less when eye tracking was accompanied by manual tracking than when not. We conclude that concurrent manual tracking enhances smooth pursuit. This enhancement is a fundamental property of eye-hand coordination that occurs regardless of the predictability of the target motion. PMID:26605840

  13. 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.

  14. [Binocular movements during pursuit and reading: eye tracking study].

    PubMed

    Boussand, F

    2012-09-01

    Detailed analysis of fine, slow ocular movements has not been the object of recent studies. With this in mind, special hardware and a simple testing protocol were developed, along with software for recording and analysis. The study of these movements, using this hardware adapted to follow both eyes, allowed the inclusion of binocularity in the precise analysis of ocular pursuit and reading. Recording the eye movements of 166 children and adults permitted identification of the main features of oculomotor development from age five years. These movements were studied during calibrated pursuit and reading. The persistence of oculomotor abnormalities during development can help to define an array of "visual immaturity" or "visual inefficiency". The study of these anomalies during reading explains some learning difficulties. PMID:22421034

  15. A Dual-Route Perspective on Eye Movements of Dyslexic Readers

    ERIC Educational Resources Information Center

    Hawelka, Stefan; Gagl, Benjamin; Wimmer, Heinz

    2010-01-01

    This study assessed eye movement abnormalities of adolescent dyslexic readers and interpreted the findings by linking the dual-route model of single word reading with the E-Z Reader model of eye movement control during silent sentence reading. A dysfunction of the lexical route was assumed to account for a reduced number of words which received…

  16. Eye Movements as Reflections of Comprehension Processes in Reading

    ERIC Educational Resources Information Center

    Rayner, Keith; Chace, Kathryn H.; Slattery, Timothy J.; Ashby, Jane

    2006-01-01

    In this article, we discuss the use of eye movement data to assess moment-to-moment comprehension processes. We first review some basic characteristics of eye movements during reading and then present two studies in which eye movements are monitored to confirm that eye movements are sensitive to (a) global text passage difficulty, and (b)…

  17. An information maximization model of eye movements

    NASA Technical Reports Server (NTRS)

    Renninger, Laura Walker; Coughlan, James; Verghese, Preeti; Malik, Jitendra

    2005-01-01

    We propose a sequential information maximization model as a general strategy for programming eye movements. The model reconstructs high-resolution visual information from a sequence of fixations, taking into account the fall-off in resolution from the fovea to the periphery. From this framework we get a simple rule for predicting fixation sequences: after each fixation, fixate next at the location that minimizes uncertainty (maximizes information) about the stimulus. By comparing our model performance to human eye movement data and to predictions from a saliency and random model, we demonstrate that our model is best at predicting fixation locations. Modeling additional biological constraints will improve the prediction of fixation sequences. Our results suggest that information maximization is a useful principle for programming eye movements.

  18. Eye movements during emotion recognition in faces.

    PubMed

    Schurgin, M W; Nelson, J; Iida, S; Ohira, H; Chiao, J Y; Franconeri, S L

    2014-01-01

    When distinguishing whether a face displays a certain emotion, some regions of the face may contain more useful information than others. Here we ask whether people differentially attend to distinct regions of a face when judging different emotions. Experiment 1 measured eye movements while participants discriminated between emotional (joy, anger, fear, sadness, shame, and disgust) and neutral facial expressions. Participant eye movements primarily fell in five distinct regions (eyes, upper nose, lower nose, upper lip, nasion). Distinct fixation patterns emerged for each emotion, such as a focus on the lips for joyful faces and a focus on the eyes for sad faces. These patterns were strongest for emotional faces but were still present when viewers sought evidence of emotion within neutral faces, indicating a goal-driven influence on eye-gaze patterns. Experiment 2 verified that these fixation patterns tended to reflect attention to the most diagnostic regions of the face for each emotion. Eye movements appear to follow both stimulus-driven and goal-driven perceptual strategies when decoding emotional information from a face. PMID:25406159

  19. Child readers' eye movements in reading Thai.

    PubMed

    Kasisopa, Benjawan; Reilly, Ronan G; Luksaneeyanawin, Sudaporn; Burnham, Denis

    2016-06-01

    It has recently been found that adult native readers of Thai, an alphabetic scriptio continua language, engage similar oculomotor patterns as readers of languages written with spaces between words; despite the lack of inter-word spaces, first and last characters of a word appear to guide optimal placement of Thai readers' eye movements, just to the left of word-centre. The issue addressed by the research described here is whether eye movements of Thai children also show these oculomotor patterns. Here the effect of first and last character frequency and word frequency on the eye movements of 18 Thai children when silently reading normal unspaced and spaced text was investigated. Linear mixed-effects model analyses of viewing time measures (first fixation duration, single fixation duration, and gaze duration) and of landing site location revealed that Thai children's eye movement patterns were similar to their adult counterparts. Both first character frequency and word frequency played important roles in Thai children's landing sites; children tended to land their eyes further into words, close to the word centre, if the word began with higher frequency first characters, and this effect was facilitated in higher frequency words. Spacing also facilitated more effective use of first character frequency and it also assisted in decreasing children's viewing time. The use of last-character frequency appeared to be a later development, affecting mainly single fixation duration and gaze duration. In general, Thai children use the same oculomotor control mechanisms in reading spaced and unspaced texts as Thai adults, who in turn have similar oculomotor control as readers of spaced texts. Thus, it appears that eye movements in reading converge on the optimal landing site using whatever cues are available to guide such placement. PMID:27137836

  20. Eye Movements Reveal Dynamics of Task Control

    ERIC Educational Resources Information Center

    Mayr, Ulrich; Kuhns, David; Rieter, Miranda

    2013-01-01

    With the goal to determine the cognitive architecture that underlies flexible changes of control settings, we assessed within-trial and across-trial dynamics of attentional selection by tracking of eye movements in the context of a cued task-switching paradigm. Within-trial dynamics revealed a switch-induced, discrete delay in onset of…

  1. Information Integration across Saccadic Eye Movements.

    ERIC Educational Resources Information Center

    Irwin, David E.

    1991-01-01

    The nature of memory storage and information integration across saccadic eye movements was studied in 6 experiments involving 12 college students. Results indicate that transsaccadic memory is an undetailed, limited-capacity long-lasting memory not strictly tied to absolute spatial position. Transsaccadic memory is very similar to visual…

  2. Eye Movement Correlates of Acquired Central Dyslexia

    ERIC Educational Resources Information Center

    Schattka, Kerstin I.; Radach, Ralph; Huber, Walter

    2010-01-01

    Based on recent progress in theory and measurement techniques, the analysis of eye movements has become one of the major methodological tools in experimental reading research. Our work uses this approach to advance the understanding of impaired information processing in acquired central dyslexia of stroke patients with aphasia. Up to now there has…

  3. 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…

  4. 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…

  5. 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

  6. Saccadic eye movement applications for psychiatric disorders

    PubMed Central

    Bittencourt, Juliana; Velasques, Bruna; Teixeira, Silmar; Basile, Luis F; Salles, José Inácio; Nardi, Antonio Egídio; Budde, Henning; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro

    2013-01-01

    Objective The study presented here analyzed the patterns of relationship between oculomotor performance and psychopathology, focusing on depression, bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and anxiety disorder. Methods Scientific articles published from 1967 to 2013 in the PubMed/Medline, ISI Web of Knowledge, Cochrane, and SciELO databases were reviewed. Results Saccadic eye movement appears to be heavily involved in psychiatric diseases covered in this review via a direct mechanism. The changes seen in the execution of eye movement tasks in patients with psychopathologies of various studies confirm that eye movement is associated with the cognitive and motor system. Conclusion Saccadic eye movement changes appear to be heavily involved in the psychiatric disorders covered in this review and may be considered a possible marker of some disorders. The few existing studies that approach the topic demonstrate a need to improve the experimental paradigms, as well as the methods of analysis. Most of them report behavioral variables (latency/reaction time), though electrophysiological measures are absent. PMID:24072973

  7. EMDR Effects on Pursuit Eye Movements

    PubMed Central

    Kapoula, Zoi; Yang, Qing; Bonnet, Audrey; Bourtoire, Pauline; Sandretto, Jean

    2010-01-01

    This study aimed to objectivize the quality of smooth pursuit eye movements in a standard laboratory task before and after an Eye Movement Desensitization and Reprocessing (EMDR) session run on seven healthy volunteers. EMDR was applied on autobiographic worries causing moderate distress. The EMDR session was complete in 5 out of the 7 cases; distress measured by SUDS (Subjective Units of Discomfort Scale) decreased to a near zero value. Smooth pursuit eye movements were recorded by an Eyelink II video system before and after EMDR. For the five complete sessions, pursuit eye movement improved after their EMDR session. Notably, the number of saccade intrusions—catch-up saccades (CUS)—decreased and, reciprocally, there was an increase in the smooth components of the pursuit. Such an increase in the smoothness of the pursuit presumably reflects an improvement in the use of visual attention needed to follow the target accurately. Perhaps EMDR reduces distress thereby activating a cholinergic effect known to improve ocular pursuit. PMID:20505828

  8. 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. PMID:27382164

  9. Eye mechanics and their implications for eye movement control

    NASA Astrophysics Data System (ADS)

    Koene, Ansgar Roald

    2002-11-01

    The topic of this thesis is the investigation of the mechanical properties of the oculomotor system and the implications of these properties for eye movement control. The investigation was conducted by means of computer models and simulations. This allowed us to combine data from anatomy, physiology and psychophysics with basic principles of physics (mechanics) and mathematics (geometry). In chapter 2 we investigate the degree to which mechanical and neural non-linearities contribute to the kinematic differences between centrifugal and centripetal saccades. On the basis of the velocity profiles of centrifugal and centripetal saccades we calculate the forces and muscle innervations during these eye movements. This was done using an inverted model of the eye plant. Our results indicate that the non-linear force-velocity relationship (i.e. muscle viscosity) of the muscles is probably the cause of the kinematic differences between centrifugal and centripetal saccades. In chapter 3 we calculate the adjustment of the saccadic command that is necessary to compensate for the eye plant non-linearities. These calculations show that the agonist and antagonist muscles require different net saccade signal gain changes. In order to better understand how this gain change is accomplished we use the inverted model of the eye plant (chapter 2) to calculate the muscle innervation profiles of saccades with different starting orientations. Based on these calculations we conclude that the saccade signal gain changes are accomplished primarily by changes in the magnitude of the saccade signal. In chapter 4 we examine the requirements that the oculomotor system must meet for the eye to be able to make desired gaze changes and fixate at various eye orientations. We first determine how the axes of action (i.e. unit moment vectors) of the muscles are related to eye orientation and the location of the effective muscle origin (i.e. the muscle pulleys). Next we show how this relation constrains

  10. The role of eye movement driven attention in functional strabismic amblyopia.

    PubMed

    Wang, Hao; Crewther, Sheila Gillard; Yin, Zheng Qin

    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

  11. 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

  12. Predictive eye movements in natural vision

    PubMed Central

    McKinney, Travis; Chajka, Kelly; Pelz, Jeff B.

    2012-01-01

    In the natural world, the brain must handle inherent delays in visual processing. This is a problem particularly during dynamic tasks. A possible solution to visuo-motor delays is prediction of a future state of the environment based on the current state and properties of the environment learned from experience. Prediction is well known to occur in both saccades and pursuit movements and is likely to depend on some kind of internal visual model as the basis for this prediction. However, most evidence comes from controlled laboratory studies using simple paradigms. In this study, we examine eye movements made in the context of demanding natural behavior, while playing squash. We show that prediction is a pervasive component of gaze behavior in this context. We show in addition that these predictive movements are extraordinarily precise and operate continuously in time across multiple trajectories and multiple movements. This suggests that prediction is based on complex dynamic visual models of the way that balls move, accumulated over extensive experience. Since eye, head, arm, and body movements all co-occur, it seems likely that a common internal model of predicted visual state is shared by different effectors to allow flexible coordination patterns. It is generally agreed that internal models are responsible for predicting future sensory state for control of body movements. The present work suggests that model-based prediction is likely to be a pervasive component in natural gaze control as well. PMID:22183755

  13. Aging effects upon pursuit eye movements.

    PubMed

    Kato, I; Sakuma, A; Ogino, S; Takahashi, K; Okada, T

    1995-01-01

    Quantitative assessment of aging effects upon pursuit eye movements was done in step-ramp stimulus conditions using 32 normal individuals. Eye movements were recorded with infrared reflection oculography. The target was a spot of 0.5 degree red lazar light. The light spot was blanked for 5 ms while the mirror galvanometer moved to a new position. Eye and target position were sampled at 250 Hz and analysed by a personal computer. In onward stimulation in which 2 degrees, 4 degrees, 6 degrees and 8 degrees position steps were followed by fixed ramp speed (10 degrees/s), and also in backward stimulation in which 2 degrees, 4 degrees, 6 degrees step positions were followed by 9 degrees, 17 degrees and 27 degrees/s, eye acceleration increased depending upon increase of retinal slip velocity in the younger group below 49 years. Among the factors effecting aging effects, the cerebrum might be important because visual recognition and eye acceleration are performed in the parietal lobe. PMID:8749143

  14. Visuo-vestibular eye movements: infantile strabismus in 3 dimensions.

    PubMed

    Brodsky, Michael C

    2005-06-01

    Infantile strabismus is accompanied by latent nystagmus, primary inferior oblique muscle overaction, and dissociated vertical divergence. If we examine the evolutionary underpinnings of these ocular rotations, we can construct a unifying mechanism for the sensorimotor abnormalities that arise in humans with infantile strabismus. Latent nystagmus, primary inferior oblique muscle overaction, and dissociated vertical divergence correspond to visual balancing reflexes that are operative in lateral-eyed animals in yaw, pitch, and roll, respectively. In humans with infantile strabismus, these subcortical visual reflexes are reactivated by a physiologic imbalance in binocular visual input, which resets central vestibular tone in 3-dimensional space. These visual reflexes reveal the evolutionary role of the eyes as sensory balance organs that can directly modulate central vestibular tone. Latent nystagmus, primary oblique muscle overaction, and dissociated vertical divergence should be reclassified as visuo-vestibular eye movements. PMID:15955986

  15. 21 CFR 886.1510 - Eye movement monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  16. 21 CFR 886.1510 - Eye movement monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  17. 21 CFR 886.1510 - Eye movement monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  18. 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...

  19. 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...

  20. Persistence in eye movement during visual search

    NASA Astrophysics Data System (ADS)

    Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

    2016-02-01

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search.

  1. Persistence in eye movement during visual search

    PubMed Central

    Amor, Tatiana A.; Reis, Saulo D. S.; Campos, Daniel; Herrmann, Hans J.; Andrade, José S.

    2016-01-01

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search. PMID:26864680

  2. Persistence in eye movement during visual search.

    PubMed

    Amor, Tatiana A; Reis, Saulo D S; Campos, Daniel; Herrmann, Hans J; Andrade, José S

    2016-01-01

    As any cognitive task, visual search involves a number of underlying processes that cannot be directly observed and measured. In this way, the movement of the eyes certainly represents the most explicit and closest connection we can get to the inner mechanisms governing this cognitive activity. Here we show that the process of eye movement during visual search, consisting of sequences of fixations intercalated by saccades, exhibits distinctive persistent behaviors. Initially, by focusing on saccadic directions and intersaccadic angles, we disclose that the probability distributions of these measures show a clear preference of participants towards a reading-like mechanism (geometrical persistence), whose features and potential advantages for searching/foraging are discussed. We then perform a Multifractal Detrended Fluctuation Analysis (MF-DFA) over the time series of jump magnitudes in the eye trajectory and find that it exhibits a typical multifractal behavior arising from the sequential combination of saccades and fixations. By inspecting the time series composed of only fixational movements, our results reveal instead a monofractal behavior with a Hurst exponent , which indicates the presence of long-range power-law positive correlations (statistical persistence). We expect that our methodological approach can be adopted as a way to understand persistence and strategy-planning during visual search. PMID:26864680

  3. Effects of hyperbaric oxygen on eye tracking abnormalities in males after mild traumatic brain injury.

    PubMed

    Cifu, David X; Hoke, Kathy W; Wetzel, Paul A; Wares, Joanna R; Gitchel, George; Carne, William

    2014-01-01

    The effects of hyperbaric oxygen (HBO2) on eye movement abnormalities in 60 military servicemembers with at least one mild traumatic brain injury (TBI) from combat were examined in a single-center, randomized, double-blind, sham-controlled, prospective study at the Naval Medicine Operational Training Center. During the 10 wk of the study, each subject was delivered a series of 40, once a day, hyperbaric chamber compressions at a pressure of 2.0 atmospheres absolute (ATA). At each session, subjects breathed one of three preassigned oxygen fractions (10.5%, 75%, or 100%) for 1 h, resulting in an oxygen exposure equivalent to breathing either surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA, respectively. Using a standardized, validated, computerized eye tracking protocol, fixation, saccades, and smooth pursuit eye movements were measured just prior to intervention and immediately postintervention. Between and within groups testing of pre- and postintervention means revealed no significant differences on eye movement abnormalities and no significant main effect for HBO2 at either 1.5 ATA or 2.0 ATA equivalent compared with the sham-control. This study demonstrated that neither 1.5 nor 2.0 ATA equivalent HBO2 had an effect on postconcussive eye movement abnormalities after mild TBI when compared with a sham-control. PMID:25436771

  4. Binocular eye movements in health and disease

    NASA Astrophysics Data System (ADS)

    Tyler, Christopher W.

    2013-03-01

    Binocular eye movements form a finely-tuned system that requires accurate coordination of the oculomotor dynamics and supports the vergence movements for tracking the fine binocular disparities required for 3D vision, and are particularly susceptible to disruption by brain injury and other neural dysfunctions. Saccadic dynamics for a population of 84 diverse participants show tight coefficients of variation of 2-10% of the mean value of each parameter. Significantly slower dynamics were seen for vertical upward saccades. Binocular coordination of saccades was accurate to within 1-4%, implying the operation of brainstem coordination mechanisms rather than independent cortical control of the two eyes. A new principle of oculomotor control - reciprocal binocular inhibition - is introduced to complement Sherrington's and Hering's Laws. This new law accounts for the fact that symmetrical vergence responses are about five times slower than saccades of the same amplitude, although a comprehensive analysis of asymmetrical vergence responses revealed unexpected variety in vergence dynamics. This analysis of the variety of human vergence responses thus contributes substantially to the understanding of the oculomotor control mechanisms underlying the generation of vergence movements and of the deficits in the oculomotor control resulting from mild traumatic brain injury.

  5. Eye Movements of Flatfish for Different Gravity Condition

    NASA Astrophysics Data System (ADS)

    Iwata, Kaori; Takabayashi, Akira; Imada, Hideki; Miyachi, Ei-Ichi

    On Earth, gravity sensation plays a basic role for all of physiological phenomena in every creature. In microgravity, loss of gravity input causes many functional disorders in animals and humans. During adaptation to microgravity, otolith-mediated response such as eye movements would alter. Flatfish provide a natural model for the study of adaptive changes in the vestibuloocular reflex. During metamorphosis, vestibular and oculomotor coordinate of flatfish displaced 90 degrees about the longitudinal body axis. Therefore, it is expected that microgravity induce the sensory mismatch in adult flatfish. In this study, we analyzed the eye movements of normal and otolith removed flatfish for body tilting and the eye movements of normal flatfish during microgravity produced by parabolic aircraft flight. The fish was fixed on the tilting table controlled by computer. The eye movements for body tilting along the different body axis were video-recorded. The vertical and torsional eye rotations were analyzed frame by frame. In normal flatfish, torsional eye movements were larger for head up or head down tilting than leftward or rightward tilting. On the other hand, vertical eye movements were larger for leftward or rightward tilting than head up or head down tilting. After removal of left side utlicular otolith, the vertical eye movement for 180 degrees body tilting disappeared. For the changes of gravity, vertical eye movements were observed. These results suggested that eye movements of flatfish adapted to Earth's gravity condition and sacculus and lagena might play important role for otolith-ocular eye movements.

  6. What Eye Movements Reveal about Deaf Readers

    PubMed Central

    Bélanger, Nathalie N.; Rayner, Keith

    2014-01-01

    Levels of illiteracy in the deaf populations around the world have been extremely high for decades and much higher than the illiteracy levels found in the general population. Research has mostly focused on deaf readers’ difficulties rather than on their strengths, which can then inform reading education. Deaf readers are a unique population. They process language and the world surrounding them mostly via the visual channel and this greatly affects how they read or might learn to read. The study of eye movements in reading provides highly sophisticated information about how words and sentences are processed and our research with deaf readers reveals the importance of their uniqueness. PMID:26594098

  7. Listening to music reduces eye movements.

    PubMed

    Schäfer, Thomas; Fachner, Jörg

    2015-02-01

    Listening to music can change the way that people visually experience the environment, probably as a result of an inwardly directed shift of attention. We investigated whether this attentional shift can be demonstrated by reduced eye movement activity, and if so, whether that reduction depends on absorption. Participants listened to their preferred music, to unknown neutral music, or to no music while viewing a visual stimulus (a picture or a film clip). Preference and absorption were significantly higher for the preferred music than for the unknown music. Participants exhibited longer fixations, fewer saccades, and more blinks when they listened to music than when they sat in silence. However, no differences emerged between the preferred music condition and the neutral music condition. Thus, music significantly reduces eye movement activity, but an attentional shift from the outer to the inner world (i.e., to the emotions and memories evoked by the music) emerged as only one potential explanation. Other explanations, such as a shift of attention from visual to auditory input, are discussed. PMID:25280523

  8. Eye Movements in Ephedrone-Induced Parkinsonism

    PubMed Central

    Megrelishvili, Marika; Sieger, Tomáš; Matoušková, Olga; Okujava, Michael; Brožová, Hana; Nikolai, Tomáš; Hanuška, Jaromír; Kapianidze, Mariam; Mikeladze, Nina; Botchorishvili, Nazi; Khatiashvili, Irine; Janelidze, Marina; Serranová, Tereza; Fiala, Ondřej; Roth, Jan; Bergquist, Jonas; Jech, Robert; Rivaud-Péchoux, Sophie; Gaymard, Bertrand; Růžička, Evžen

    2014-01-01

    Patients with ephedrone parkinsonism (EP) show a complex, rapidly progressive, irreversible, and levodopa non-responsive parkinsonian and dystonic syndrome due to manganese intoxication. Eye movements may help to differentiate parkinsonian syndromes providing insights into which brain networks are affected in the underlying disease, but they have never been systematically studied in EP. Horizontal and vertical eye movements were recorded in 28 EP and compared to 21 Parkinson's disease (PD) patients, and 27 age- and gender-matched healthy subjects using standardized oculomotor tasks with infrared videooculography. EP patients showed slow and hypometric horizontal saccades, an increased occurrence of square wave jerks, long latencies of vertical antisaccades, a high error rate in the horizontal antisaccade task, and made more errors than controls when pro- and antisaccades were mixed. Based on oculomotor performance, a direct differentiation between EP and PD was possible only by the velocity of horizontal saccades. All remaining metrics were similar between both patient groups. EP patients present extensive oculomotor disturbances probably due to manganese-induced damage to the basal ganglia, reflecting their role in oculomotor system. PMID:25117825

  9. Active inference, eye movements and oculomotor delays.

    PubMed

    Perrinet, Laurent U; Adams, Rick A; Friston, Karl J

    2014-12-01

    This paper considers the problem of sensorimotor delays in the optimal control of (smooth) eye movements under uncertainty. Specifically, we consider delays in the visuo-oculomotor loop and their implications for active inference. Active inference uses a generalisation of Kalman filtering to provide Bayes optimal estimates of hidden states and action in generalised coordinates of motion. Representing hidden states in generalised coordinates provides a simple way of compensating for both sensory and oculomotor delays. The efficacy of this scheme is illustrated using neuronal simulations of pursuit initiation responses, with and without compensation. We then consider an extension of the generative model to simulate smooth pursuit eye movements-in which the visuo-oculomotor system believes both the target and its centre of gaze are attracted to a (hidden) point moving in the visual field. Finally, the generative model is equipped with a hierarchical structure, so that it can recognise and remember unseen (occluded) trajectories and emit anticipatory responses. These simulations speak to a straightforward and neurobiologically plausible solution to the generic problem of integrating information from different sources with different temporal delays and the particular difficulties encountered when a system-like the oculomotor system-tries to control its environment with delayed signals. PMID:25128318

  10. Saccadic Eye Movements in Anorexia Nervosa

    PubMed Central

    Phillipou, Andrea; Rossell, Susan Lee; Gurvich, Caroline; Hughes, Matthew Edward; Castle, David Jonathan; Nibbs, Richard Grant; Abel, Larry Allen

    2016-01-01

    Background Anorexia Nervosa (AN) has a mortality rate among the highest of any mental illness, though the factors involved in the condition remain unclear. Recently, the potential neurobiological underpinnings of the condition have become of increasing interest. Saccadic eye movement tasks have proven useful in our understanding of the neurobiology of some other psychiatric illnesses as they utilise known brain regions, but to date have not been examined in AN. The aim of this study was to investigate whether individuals with AN differ from healthy individuals in performance on a range of saccadic eye movements tasks. Methods 24 females with AN and 25 healthy individuals matched for age, gender and premorbid intelligence participated in the study. Participants were required to undergo memory-guided and self-paced saccade tasks, and an interleaved prosaccade/antisaccade/no-go saccade task while undergoing functional magnetic resonance imaging (fMRI). Results AN participants were found to make prosaccades of significantly shorter latency than healthy controls. AN participants also made an increased number of inhibitory errors on the memory-guided saccade task. Groups did not significantly differ in antisaccade, no-go saccade or self-paced saccade performance, or fMRI findings. Discussion The results suggest a potential role of GABA in the superior colliculus in the psychopathology of AN. PMID:27010196

  11. Eye movements as probes of lexico-semantic processing in a patient with primary progressive aphasia.

    PubMed

    Seckin, Mustafa; Mesulam, M-Marsel; Rademaker, Alfred W; Voss, Joel L; Weintraub, Sandra; Rogalski, Emily J; Hurley, Robert S

    2016-01-01

    Eye movement trajectories during a verbally cued object search task were used as probes of lexico-semantic associations in an anomic patient with primary progressive aphasia. Visual search was normal on trials where the target object could be named but became lengthy and inefficient on trials where the object failed to be named. The abnormality was most profound if the noun denoting the object could not be recognized. Even trials where the name of the target object was recognized but not retrieved triggered abnormal eye movements, demonstrating that retrieval failures can have underlying associative components despite intact comprehension of the corresponding noun. PMID:25982291

  12. 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.

  13. Eye and head movements shape gaze shifts in Indian peafowl.

    PubMed

    Yorzinski, Jessica L; Patricelli, Gail L; Platt, Michael L; Land, Michael F

    2015-12-01

    Animals selectively direct their visual attention toward relevant aspects of their environments. They can shift their attention using a combination of eye, head and body movements. While we have a growing understanding of eye and head movements in mammals, we know little about these processes in birds. We therefore measured the eye and head movements of freely behaving Indian peafowl (Pavo cristatus) using a telemetric eye-tracker. Both eye and head movements contributed to gaze changes in peafowl. When gaze shifts were smaller, eye movements played a larger role than when gaze shifts were larger. The duration and velocity of eye and head movements were positively related to the size of the eye and head movements, respectively. In addition, the coordination of eye and head movements in peafowl differed from that in mammals; peafowl exhibited a near-absence of the vestibulo-ocular reflex, which may partly result from the peafowl's ability to move their heads as quickly as their eyes. PMID:26486363

  14. Graves' ophthalmopathy evaluated by infrared eye-movement recordings

    SciTech Connect

    Feldon, S.E.; Unsoeld, R.

    1982-02-01

    Thirteen patients with varying degrees of Graves' ophthalmopathy were examined using high-resolution infrared oculography to determine peak velocities for horizontal eye movements between 3 degrees and 30 degrees. As severity of the orbital disease increased, peak velocities became substantially lower. Vertical-muscle surgery failed to have any effect on peak velocity of horizontal eye movements. In contrast, orbital decompression caused notable improvement in peak velocity of eye movements. Eye-movement recordings, which provide a measure of extraocular muscle function rather than structure, may provide a safe, sensitive, and accurate method for classifying and following up patients with Graves' ophthalmopathy.

  15. Saccadic Eye Movement Speed and Motor Response Execution

    ERIC Educational Resources Information Center

    Williams, Harriet G.; Helfrich, Janet

    1977-01-01

    Evidence was found to indicate that training to improve the speed of saccadic eye movement (movement from one fixation point to another) also resulted in observable changes in batting performance among a sample group of high school girls. (MJB)

  16. Fixational eye movements predict visual sensitivity.

    PubMed

    Scholes, Chris; McGraw, Paul V; Nyström, Marcus; Roach, Neil W

    2015-10-22

    During steady fixation, observers make small fixational saccades at a rate of around 1-2 per second. Presentation of a visual stimulus triggers a biphasic modulation in fixational saccade rate-an initial inhibition followed by a period of elevated rate and a subsequent return to baseline. Here we show that, during passive viewing, this rate signature is highly sensitive to small changes in stimulus contrast. By training a linear support vector machine to classify trials in which a stimulus is either present or absent, we directly compared the contrast sensitivity of fixational eye movements with individuals' psychophysical judgements. Classification accuracy closely matched psychophysical performance, and predicted individuals' threshold estimates with less bias and overall error than those obtained using specific features of the signature. Performance of the classifier was robust to changes in the training set (novel subjects and/or contrasts) and good prediction accuracy was obtained with a practicable number of trials. Our results indicate a tight coupling between the sensitivity of visual perceptual judgements and fixational eye control mechanisms. This raises the possibility that fixational saccades could provide a novel and objective means of estimating visual contrast sensitivity without the need for observers to make any explicit judgement. PMID:26468244

  17. An integrated model of fixational eye movements and microsaccades.

    PubMed

    Engbert, Ralf; Mergenthaler, Konstantin; Sinn, Petra; Pikovsky, Arkady

    2011-09-27

    When we fixate a stationary target, our eyes generate miniature (or fixational) eye movements involuntarily. These fixational eye movements are classified as slow components (physiological drift, tremor) and microsaccades, which represent rapid, small-amplitude movements. Here we propose an integrated mathematical model for the generation of slow fixational eye movements and microsaccades. The model is based on the concept of self-avoiding random walks in a potential, a process driven by a self-generated activation field. The self-avoiding walk generates persistent movements on a short timescale, whereas, on a longer timescale, the potential produces antipersistent motions that keep the eye close to an intended fixation position. We introduce microsaccades as fast movements triggered by critical activation values. As a consequence, both slow movements and microsaccades follow the same law of motion; i.e., movements are driven by the self-generated activation field. Thus, the model contributes a unified explanation of why it has been a long-standing problem to separate slow movements and microsaccades with respect to their motion-generating principles. We conclude that the concept of a self-avoiding random walk captures fundamental properties of fixational eye movements and provides a coherent theoretical framework for two physiologically distinct movement types. PMID:21873243

  18. Eye Movements and Parafoveal Processing during Reading in Korean

    ERIC Educational Resources Information Center

    Kim, Young-Suk; Radach, Ralph; Vorstius, Christian

    2012-01-01

    Parafoveal word processing was examined during Korean reading. Twenty-four native speakers of Korean read sentences in two conditions while their eye movements were being monitored. The boundary paradigm (Rayner, 1975) was used to create a mismatch between characters displayed before and after an eye movement contingent display change. In the…

  19. The Role of Eye Movements in Subitizing and Counting

    ERIC Educational Resources Information Center

    Watson, Derrick G.; Maylor, Elizabeth A.; Bruce, Lucy A. M.

    2007-01-01

    Previous work has suggested that eye movements may be necessary for accurate enumeration beyond the subitization range of about 4 items. This study determined the frequency of eye movements normally made during enumeration, their relationship to response times, and whether they are required for accurate performance. This was achieved by monitoring…

  20. 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…

  1. 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…

  2. Envisioning Story: The Eye Movements of Beginning Readers

    ERIC Educational Resources Information Center

    Duckett, Peter

    2003-01-01

    Miscue analysis and eye movement analysis are used to explore the reading process of first-grade beginning readers as they use pictures and print in a picture book designed for instructional purposes. Eye movement miscue analysis (EMMA) is also used as a tool to gain insights into the reading strategies of the beginning readers in this study.…

  3. Cue predictability changes scaling in eye-movement fluctuations.

    PubMed

    Wallot, Sebastian; Coey, Charles A; Richardson, Michael J

    2015-10-01

    Recent research has provided evidence for scaling-relations in eye-movement fluctuations, but not much is known about what these scaling relations imply about cognition or eye-movement control. Generally, scaling relations in behavioral and neurophysiological data have been interpreted as an indicator for the coordination of neurophysiological and cognitive processes. In this study, we investigated the effect of predictability in timing and gaze-direction on eye-movement fluctuations. Participants performed a simple eye-movement task, in which a visual cue prompted their gaze to different locations on a spatial layout, and the predictability about temporal and directional aspects of the cue were manipulated. The results showed that scaling exponents in eye-movements decreased with predictability and were related to the participants' perceived effort during the task. In relation to past research, these findings suggest that scaling exponents reflect a relative demand for voluntary control during task performance. PMID:26337612

  4. [Parkinson Disease With Rapid Eye Movement Sleep Behavior Disorder].

    PubMed

    Hu, Yang; Zhang, Wei

    2015-06-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by lack of muscle atonia during REM sleep and enactment of dream content. RBD is associated with Parkinson disease (PD) and has high incidence in PD patients. PD patient with RBD mainly presents rigid type, has longer disease duration, more severe motor and non-motor symptoms and poorer activity of daily living and life quality. The pathophysiological mechanisms of RBD may be related to dysfunctions of pontine tegmentum, locus coeruleus/sub-locus coeruleus complex and related projections. The diagnosis of RBD depends on clinical histories and video-polysomnography (v-PSG). Besides treatment for PD, protective measures have to be taken for patients and their sleep partners. If abnormal behaviors during sleep cause distress and danger,patients should be given drug therapy. PMID:26521483

  5. Insulinoma Masquerading as Rapid Eye Movement Sleep Behavior Disorder

    PubMed Central

    Suzuki, Keisuke; Kawasaki, Akiko; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Kanbayashi, Takashi; Sato, Masatoshi; Shimizu, Tetsuo; Hirata, Koichi

    2015-01-01

    Abstract Insulinoma is a rare endocrine tumor that can cause a wide variety of symptoms, including abnormal nocturnal behavior. We report on 3 patients with insulinoma who presented with abnormal nocturnal behavior and injury during sleep, which simulated rapid eye movement (REM) sleep behavior disorder (RBD). In case 1, the fasting glucose level was 15 mg/dL, and insulin levels were elevated (15 μU/mL). In case 3, when the patient was transferred to the hospital because of a disturbance of consciousness, hypoglycemia (29 mg/dL) was detected. In contrast, in case 2, fasting glucose sampling did not indicate hypoglycemia, but continuous glucose monitoring revealed nocturnal hypoglycemia. The time from initial symptoms to a diagnosis of insulinoma ranged from 7 months to 2 years. All 3 patients had previously received anticonvulsant drugs for suspected epilepsy, but the medications were ineffective. Polysomnography showed no evidence of REM sleep without atonia in any of the 3 patients. No patient remembered any events that occurred during sleep. When a patient manifests abnormal behavior during the night and early morning, glucose monitoring should be performed, especially during the night and early morning. Clinicians should be aware that although insulinomas are rare, they can mimic parasomnias, such as RBD. PMID:26107678

  6. 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

  7. Motion dependence of smooth pursuit eye movements in the marmoset

    PubMed Central

    Priebe, Nicholas J.; Miller, Cory T.

    2015-01-01

    Smooth pursuit eye movements stabilize slow-moving objects on the retina by matching eye velocity with target velocity. Two critical components are required to generate smooth pursuit: first, because it is a voluntary eye movement, the subject must select a target to pursue to engage the tracking system; and second, generating smooth pursuit requires a moving stimulus. We examined whether this behavior also exists in the common marmoset, a New World primate that is increasingly attracting attention as a genetic model for mental disease and systems neuroscience. We measured smooth pursuit in two marmosets, previously trained to perform fixation tasks, using the standard Rashbass step-ramp pursuit paradigm. We first measured the aspects of visual motion that drive pursuit eye movements. Smooth eye movements were in the same direction as target motion, indicating that pursuit was driven by target movement rather than by displacement. Both the open-loop acceleration and closed-loop eye velocity exhibited a linear relationship with target velocity for slow-moving targets, but this relationship declined for higher speeds. We next examined whether marmoset pursuit eye movements depend on an active engagement of the pursuit system by measuring smooth eye movements evoked by small perturbations of motion from fixation or during pursuit. Pursuit eye movements were much larger during pursuit than from fixation, indicating that pursuit is actively gated. Several practical advantages of the marmoset brain, including the accessibility of the middle temporal (MT) area and frontal eye fields at the cortical surface, merit its utilization for studying pursuit movements. PMID:25867740

  8. Eye Movement Patterns Characteristic of Cognitive Style.

    PubMed

    Nitzan-Tamar, Ortal; Kramarski, Bracha; Vakil, Eli

    2016-06-01

    Various tools have been designed to classify the wholistic/analytic cognitive style, based mostly on behavioral data that reveals little about how these processes function. The main goal of this study is to characterize patterns of eye movements (EM) that are typical of learners with tendencies toward wholistic/analytic styles. Forty students completed the E-CSA-W/A test, while their EM were simultaneously monitored. The results revealed that the overall response time of the wholist group was lower in both tasks. The differences in response time between the groups are interpreted as being influenced by impulsive/reflective styles. While the behavioral data provide us with the end result and quantitative differences between the groups, EM provide us with the qualitative information about the process that led to the response. The study showed that the wholist group is characterized by less fixations and transitions than the analytic group, which is interpreted as reflecting use of whole/partial strategy. PMID:27404984

  9. Oculometer for remote tracking of eye movement

    NASA Technical Reports Server (NTRS)

    Mason, K. A.; Merchant, J.

    1969-01-01

    Prototype oculometer which tracks lateral eye position and measures the direction of the eyes optical axis, pupil size, and blink occurrence performs measurements on the subject on a real-time basis from a remote location.

  10. [A case of pontine hemorrhage presenting with abnormal vertical ocular movements].

    PubMed

    Kaneko, A; Iwasaki, S; Hamaguchi, K

    1994-10-01

    A 52-year-old woman was admitted to hospital because of sudden loss of consciousness. Neurological examination on admission revealed a comatose consciousness level, horizontal and upward palsies of both eyes and quadriparesis. The diagnosis of pontine hemorrhage was confirmed based on a brain CT scan, which showed a high density area involving the bilateral pontine tegmentum and right midbrain tegmentum at the inferior collicular level. The left eye moved downward below its primary position, and the movements usually comprised rapid downward and slow upward excursions and, on occasion, slow downward and rapid upward excursions, and were arrhythmical with irregular amplitudes. Oculocephalic maneuver did not modify the ocular movements. No horizontal movements were seen with ice-cold water irrigation into the ear canal on either side. Sixty days after hemorrhage onset, her right eye began to assume the same abnormal vertical movements as the left one, and 90 days after their onset, the ocular movements became oscillations. The abnormal vertical ocular movements in our patient were characterized by irregularities of phase, rhythm and amplitude. Accordingly, they were easily differentiated from ocular bobbing and ocular dipping. As these abnormal ocular movements resembled those of a float pulled by a fish, we propose they be termed ocular floating. The paramedian pontine reticular formation (PPRF) is believed to excite the burst neurons of the rosral interstitial nucleus of medial longitudinal fasciculus (riMLF) responsible for upward gaze and inhibit those for downward gaze. This role was suggested by the clinical observation that a pontine tegmental lesion causes upward gaze palsy.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7834949

  11. Cognitive Processes Involved in Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Barnes, G. R.

    2008-01-01

    Ocular pursuit movements allow moving objects to be tracked with a combination of smooth movements and saccades. The principal objective is to maintain smooth eye velocity close to object velocity, thus minimising retinal image motion and maintaining acuity. Saccadic movements serve to realign the image if it falls outside the fovea, the area of…

  12. Eye movements and their functions in everyday tasks

    PubMed Central

    Foulsham, T

    2015-01-01

    Human saccades and fixations have numerous functions in complex everyday tasks, which have sometimes been neglected in simple experimental situations. In this review I describe some of the characteristics of eye movement behaviour during real-world interactions with objects, while walking in natural environments and while holding a conversation. When performing real-world actions and walking around the world, we fixate relevant features at critical time points during the task. The eye movements between these fixations are planned and coordinated alongside head and body movements, often occurring a short time before the corresponding action. In social interactions, eye movements are both a mechanism for taking in information (for example, when looking at someone's face or following their gaze) and for signalling one's attention to another person. Thus eye movements are specific to a particular task context and subject to high-level planning and control during everyday actions. PMID:25397783

  13. Voluntary eye movements direct attention on the mental number space.

    PubMed

    Ranzini, Mariagrazia; Lisi, Matteo; Zorzi, Marco

    2016-05-01

    Growing evidence suggests that orienting visual attention in space can influence the processing of numerical magnitude, with leftward orienting speeding up the processing of small numbers relative to larger ones and the converse for rightward orienting. The manipulation of eye movements is a convenient way to direct visuospatial attention, but several aspects of the complex relationship between eye movements, attention orienting and number processing remain unexplored. In a previous study, we observed that inducing involuntary, reflexive eye movements by means of optokinetic stimulation affected number processing only when numerical magnitude was task relevant (i.e., during magnitude comparison, but not during parity judgment; Ranzini et al., in J Cogn Psychol 27, 459-470, (2015). Here, we investigated whether processing of task-irrelevant numerical magnitude can be modulated by voluntary eye movements, and whether the type of eye movements (smooth pursuit vs. saccades) would influence this interaction. Participants tracked with their gaze a dot while listening to a digit. The numerical task was to indicate whether the digit was odd or even through non-spatial, verbal responses. The dot could move leftward or rightward either continuously, allowing tracking by smooth pursuit eye movements, or in discrete steps across a series of adjacent locations, triggering a sequence of saccades. Both smooth pursuit and saccadic eye movements similarly affected number processing and modulated response times for large numbers as a function of direction of motion. These findings suggest that voluntary eye movements redirect attention in mental number space and highlight that eye movements should play a key factor in the investigation of number-space interactions. PMID:26838166

  14. Increased Saccadic Rate during Smooth Pursuit Eye Movements in Patients at Ultra High Risk for Developing a Psychosis

    ERIC Educational Resources Information Center

    van Tricht, M. J.; Nieman, D. H.; Bour, L. J.; Boeree, T.; Koelman, J. H. T. M.; de Haan, L.; Linszen, D. H.

    2010-01-01

    Abnormalities in eye tracking are consistently observed in schizophrenia patients and their relatives and have been proposed as an endophenotype of the disease. The aim of this study was to investigate the performance of patients at Ultra High Risk (UHR) for developing psychosis on a task of smooth pursuit eye movement (SPEM). Forty-six UHR…

  15. Imagined motor action and eye movements in schizophrenia

    PubMed Central

    Delerue, Céline; Boucart, Muriel

    2013-01-01

    Visual exploration and planning of actions are reported to be abnormal in schizophrenia. Most of the studies monitoring eye movements in patients with schizophrenia have been performed under free-viewing condition. The present study was designed to assess whether mentally performing an action modulates the visuomotor behavior in patients with schizophrenia and in healthy controls. Visual scan paths were monitored in eighteen patients with schizophrenia and in eighteen healthy controls. Participants performed two tasks in which they were asked either to (1) look at a scene on a computer screen (free viewing), or (2) picture themselves making a sandwich in front of a computer screen (active viewing). The scenes contained both task-relevant and task-irrelevant objects. Temporal and spatial characteristics of scan paths were compared for each group and each task. The results indicate that patients with schizophrenia exhibited longer fixation durations, and fewer fixations, than healthy controls in the free viewing condition. The patients' visual exploration improved in the active viewing condition. However, patients looked less at task-relevant objects and looked more at distractors than controls in the active viewing condition in which they were asked to picture themselves making a sandwich in moving their eyes to task-relevant objects on an image. These results are consistent with the literature on deficits in motor imagery in patients with schizophrenia and it extends the impairment to visual exploration in an action imagery task. PMID:23874317

  16. Smooth-pursuit eye movement and saccadic intrusions in obsessive-compulsive disorder.

    PubMed

    Pallanti, S; Grecu, L M; Gangemi, P F; Massi, S; Parigi, A; Arnetoli, G; Quercioli, L; Zaccara, G

    1996-12-01

    Although several reports agree that smooth-pursuit eye movement (SPEM) is abnormal in some obsessive-compulsive disordered (OCD) patients, differences between treatments and lack of accuracy in control selection make the results controversial. Although reduced gain seems the most accepted abnormality, the characteristics of saccadic disruption of smooth pursuit are as yet unspecified. SPEMs in 21 OCD patients (DSM-III-R) and 21 healthy subjects recruited from the community were studied through a multiple target velocity task . The two groups were individually matched on age, gender, and level of education. None of the subjects had a history of substance dependence apart from the smokers who refrained from smoking in the 2 hours prior to the test. A significantly lower SPEM gain and increased number and frequency of anticipatory saccades (ASs) was found in OCD patients as compared with control subjects. No relationship emerged between eye movement abnormalities and clinical variables explored. PMID:8931920

  17. Poor performance in smooth pursuit and antisaccadic eye-movement tasks in healthy siblings of patients with schizophrenia.

    PubMed

    Karoumi, B; Saoud, M; d'Amato, T; Rosenfeld, F; Denise, P; Gutknecht, C; Gaveau, V; Beaulieu, F E; Daléry, J; Rochet, T

    2001-04-15

    This study examines the area of eye movement dysfunctions as an indicator of vulnerability to schizophrenia. Eye movement performance was investigated with three different paradigms: Smooth Pursuit Eye Movements (SPEM); Visually Guided Saccades (VGS); and Antisaccades (AS) in 21 clinically stable patients with schizophrenia, 21 of their healthy, biological full siblings and 21 healthy control subjects. The three groups did not differ on VGS performance, whereas both patients and their siblings showed lower SPEM gain, an increased catch-up Saccades (CUS) rate, reduced AS accuracy and an increased number of AS errors in comparison to control subjects. In addition, patients with schizophrenia exhibited increased AS latency. Among the patients with schizophrenia, eye movement abnormalities did not correlate with age, gender, clinical state or duration of illness. These data suggest that abnormalities of SPEM and AS may represent neurobiological markers of the vulnerability to schizophrenia in individuals at high genetic risk for the disease. PMID:11311924

  18. 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.

  19. Tracking Kids' Eye Movements Might Shed New Light on Autism

    MedlinePlus

    ... Kids' Eye Movements Might Shed New Light on Autism When conversations turn emotional, children with ASD change ... HealthDay News) -- New findings about where children with autism look during conversations could lead to changes in ...

  20. Saccadic Eye Movement Task Identifies Cognitive Deficits in Children with Schizophrenia, but Not in Unaffected Child Relatives

    ERIC Educational Resources Information Center

    Ross, Randal G.; Heinlein, Shari; Zerbe, Gary O.; Radant, Allen

    2005-01-01

    Background: The delayed oculomotor response (DOR) task requires response inhibition followed by movement of gaze towards a known spatial location without a current stimulus. Abnormalities in response inhibition and in the spatial accuracy of the eye movement are found in individuals with schizophrenia and in many of their relatives, supporting the…

  1. Eye Movements in Reading as Rational Behavior

    ERIC Educational Resources Information Center

    Bicknell, Klinton

    2011-01-01

    Moving one's eyes while reading is one of the most complex everyday tasks humans face. To perform efficiently, readers must make decisions about when and where to move their eyes every 200-300ms. Over the past decades, it has been demonstrated that these fine-grained decisions are influenced by a range of linguistic properties of the text, and…

  2. Visual Short-Term Memory During Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Kerzel, Dirk; Ziegler, Nathalie E.

    2005-01-01

    Visual short-term memory (VSTM) was probed while observers performed smooth pursuit eye movements. Smooth pursuit keeps a moving object stabilized in the fovea. VSTM capacity for position was reduced during smooth pursuit compared with a condition with eye fixation. There was no difference between a condition in which the items were approximately…

  3. 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…

  4. Predicting the Valence of a Scene from Observers’ Eye Movements

    PubMed Central

    R.-Tavakoli, Hamed; Atyabi, Adham; Rantanen, Antti; Laukka, Seppo J.; Nefti-Meziani, Samia; Heikkilä, Janne

    2015-01-01

    Multimedia analysis benefits from understanding the emotional content of a scene in a variety of tasks such as video genre classification and content-based image retrieval. Recently, there has been an increasing interest in applying human bio-signals, particularly eye movements, to recognize the emotional gist of a scene such as its valence. In order to determine the emotional category of images using eye movements, the existing methods often learn a classifier using several features that are extracted from eye movements. Although it has been shown that eye movement is potentially useful for recognition of scene valence, the contribution of each feature is not well-studied. To address the issue, we study the contribution of features extracted from eye movements in the classification of images into pleasant, neutral, and unpleasant categories. We assess ten features and their fusion. The features are histogram of saccade orientation, histogram of saccade slope, histogram of saccade length, histogram of saccade duration, histogram of saccade velocity, histogram of fixation duration, fixation histogram, top-ten salient coordinates, and saliency map. We utilize machine learning approach to analyze the performance of features by learning a support vector machine and exploiting various feature fusion schemes. The experiments reveal that ‘saliency map’, ‘fixation histogram’, ‘histogram of fixation duration’, and ‘histogram of saccade slope’ are the most contributing features. The selected features signify the influence of fixation information and angular behavior of eye movements in the recognition of the valence of images. PMID:26407322

  5. Predicting the Valence of a Scene from Observers' Eye Movements.

    PubMed

    R-Tavakoli, Hamed; Atyabi, Adham; Rantanen, Antti; Laukka, Seppo J; Nefti-Meziani, Samia; Heikkilä, Janne

    2015-01-01

    Multimedia analysis benefits from understanding the emotional content of a scene in a variety of tasks such as video genre classification and content-based image retrieval. Recently, there has been an increasing interest in applying human bio-signals, particularly eye movements, to recognize the emotional gist of a scene such as its valence. In order to determine the emotional category of images using eye movements, the existing methods often learn a classifier using several features that are extracted from eye movements. Although it has been shown that eye movement is potentially useful for recognition of scene valence, the contribution of each feature is not well-studied. To address the issue, we study the contribution of features extracted from eye movements in the classification of images into pleasant, neutral, and unpleasant categories. We assess ten features and their fusion. The features are histogram of saccade orientation, histogram of saccade slope, histogram of saccade length, histogram of saccade duration, histogram of saccade velocity, histogram of fixation duration, fixation histogram, top-ten salient coordinates, and saliency map. We utilize machine learning approach to analyze the performance of features by learning a support vector machine and exploiting various feature fusion schemes. The experiments reveal that 'saliency map', 'fixation histogram', 'histogram of fixation duration', and 'histogram of saccade slope' are the most contributing features. The selected features signify the influence of fixation information and angular behavior of eye movements in the recognition of the valence of images. PMID:26407322

  6. Gross Motor Development, Movement Abnormalities, and Early Identification of Autism

    ERIC Educational Resources Information Center

    Ozonoff, Sally; Young, Gregory S.; Goldring, Stacy; Greiss-Hess, Laura; Herrera, Adriana M.; Steele, Joel; Macari, Suzanne; Hepburn, Susan; Rogers, Sally J.

    2008-01-01

    Gross motor development (supine, prone, rolling, sitting, crawling, walking) and movement abnormalities were examined in the home videos of infants later diagnosed with autism (regression and no regression subgroups), developmental delays (DD), or typical development. Group differences in maturity were found for walking, prone, and supine, with…

  7. Cross-Coupled Eye Movement Supports Neural Origin of Pattern Strabismus

    PubMed Central

    Ghasia, Fatema F.; Shaikh, Aasef G.; Jacobs, Jonathan; Walker, Mark F.

    2015-01-01

    Purpose. Pattern strabismus describes vertically incomitant horizontal strabismus. Conventional theories emphasized the role of orbital etiologies, such as abnormal fundus torsion and misaligned orbital pulleys as a cause of the pattern strabismus. Experiments in animal models, however, suggested the role of abnormal cross-connections between the neural circuits. We quantitatively assessed eye movements in patients with pattern strabismus with a goal to delineate the role of neural circuits versus orbital etiologies. Methods. We measured saccadic eye movements with high-precision video-oculography in 14 subjects with pattern strabismus, 5 with comitant strabismus, and 15 healthy controls. We assessed change in eye position in the direction orthogonal to that of the desired eye movement (cross-coupled responses). We used fundus photography to quantify the fundus torsion. Results. We found cross-coupling of saccades in all patients with pattern strabismus. The cross-coupled responses were in the same direction in both eyes, but larger in the nonviewing eye. All patients had clinically apparent inferior oblique overaction with abnormal excylotorsion. There was no correlation between the amount of the fundus torsion or the grade of oblique overaction and the severity of cross-coupling. The disconjugacy in the saccade direction and amplitude in pattern strabismics did not have characteristics predicted by clinically apparent inferior oblique overaction. Conclusions. Our results validated primate models of pattern strabismus in human patients. We found no correlation between ocular torsion or oblique overaction and cross-coupling. Therefore, we could not ascribe cross-coupling exclusively to the orbital etiology. Patients with pattern strabismus could have abnormalities in the saccade generators. PMID:26024072

  8. ILAB: a program for postexperimental eye movement analysis.

    PubMed

    Gitelman, Darren R

    2002-11-01

    The recording and analysis of eye movements are fundamental to a diverse set of research applications, including studies in which reading, visual search, and both overt and covert visuospatial attention are examined. Software tools supplied with commonly available eye-tracking equipment have generally been limited in functionality and nonextensible. Because of this dearth of available software, ELAB was created to provide an extensible framework for analyzing various aspects of eye movements. The program consists of a series of open-source MATLAB functions. The program's data structures keep raw data, analysis preferences, and analyzed data separate, thus maintaining data fidelity and promoting extensibility. PMID:12564563

  9. 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.

  10. Blurring emotional memories using eye movements: individual differences and speed of eye movements

    PubMed Central

    van Schie, Kevin; van Veen, Suzanne C.; Engelhard, Iris M.; Klugkist, Irene; van den Hout, Marcel A.

    2016-01-01

    Background In eye movement desensitization and reprocessing (EMDR), patients make eye movements (EM) while recalling traumatic memories. Making EM taxes working memory (WM), which leaves less resources available for imagery of the memory. This reduces memory vividness and emotionality during future recalls. WM theory predicts that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM) whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM). Objective We experimentally examined and tested four prespecified hypotheses regarding the role of WMC and EM speed in reducing emotionality and vividness ratings: 1) EM—regardless of WMC and EM speed—are more effective compared to no dual task, 2) increasing EM speed only affects the decrease in memory ratings irrespective of WMC, 3) low-WMC individuals—compared to high-WMC individuals—benefit more from making either type of EM, 4) the EM intervention is most effective when—as predicted by WM theory—EM are adjusted to WMC. Method Undergraduates with low (n=31) or high (n=35) WMC recalled three emotional memories and rated vividness and emotionality before and after each condition (recall only, recall + slow EM, and recall + fast EM). Results Contrary to the theory, the data do not support the hypothesis that EM speed should be adjusted to WMC (hypothesis 4). However, the data show that a dual task in general is more effective in reducing memory ratings than no dual task (hypothesis 1), and that a more cognitively demanding dual task increases the intervention's effectiveness (hypothesis 2). Conclusions Although adjusting EM speed to an individual's WMC seems a straightforward clinical implication, the data do not show any indication that such a titration is helpful. PMID:27387843

  11. Quantification of vestibular-induced eye movements in zebrafish larvae

    PubMed Central

    2010-01-01

    Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR), a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf), which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs. PMID:20815905

  12. Rapid eye movement sleep behavior disorder and rapid eye movement sleep without atonia in narcolepsy.

    PubMed

    Dauvilliers, Yves; Jennum, Poul; Plazzi, Giuseppe

    2013-08-01

    Narcolepsy is a rare disabling hypersomnia disorder that may include cataplexy, sleep paralysis, hypnagogic hallucinations, and sleep-onset rapid eye movement (REM) periods, but also disrupted nighttime sleep by nocturnal awakenings, and REM sleep behavior disorder (RBD). RBD is characterized by dream-enacting behavior and impaired motor inhibition during REM sleep (REM sleep without atonia, RSWA). RBD is commonly associated with neurodegenerative disorders including Parkinsonisms, but is also reported in narcolepsy in up to 60% of patients. RBD in patients with narcolepsy is, however, a distinct phenotype with respect to other RBD patients and characterized also by absence of gender predominance, elementary rather than complex movements, less violent behavior and earlier age at onset of motor events, and strong association to narcolepsy with cataplexy/hypocretin deficiency. Patients with narcolepsy often present dissociated sleep features including RSWA, increased density of phasic chin EMG and frequent shift from REM to NREM sleep, with or without associated clinical RBD. Most patients with narcolepsy with cataplexy lack the hypocretin neurons in the lateral hypothalamus. Tonic and phasic motor activities in REM sleep and dream-enacting behavior are mostly reported in presence of cataplexy. Narcolepsy without cataplexy is a condition rarely associated with hypocretin deficiency. We proposed that hypocretin neurons are centrally involved in motor control during wakefulness and sleep in humans, and that hypocretin deficiency causes a functional defect in the motor control involved in the development of cataplexy during wakefulness and RBD/RSWA/phasic motor activity during REM sleep. PMID:23219054

  13. Natural coordinates for specification of eye movements.

    PubMed

    Clement, R A

    1991-01-01

    Tweed and Vilis (Journal of Neurophysiology, 58, 832-849, 1987) have argued that quaternion algebra provides the most appropriate description of the rotations of the eye, and have derived a three-dimensional model of gaze control based on quaternion operations. Euler angles give a simpler description of the rotations of the eye, and can also be used to formulate an alternative version of the three-dimensional gaze control model. Comparison of the two versions of the model highlights the distinction between the functional predictions of the model, and the predictions which depend only on the choice of mathematical descriptions. PMID:1771787

  14. Prevention of coordinated eye movements and steering impairs driving performance.

    PubMed

    Marple-Horvat, D E; Chattington, M; Anglesea, M; Ashford, D G; Wilson, M; Keil, D

    2005-06-01

    When approaching a bend in the road, a driver looks across to the inside kerb before turning the steering wheel. Eye movements and steering are tightly linked, with the eyes leading, which means that the oculomotor controller can assist the neural centres controlling steering. This optimum coordination is observed for all drivers; but despite being the preferred solution to the motor-control problem of successfully steering along a winding road, the question remains as to how crucial such coordinated eye and steering movements are for driving performance. Twenty subjects repeatedly drove a simulated stage of the World Rally Championship, aiming to complete the course in the fastest possible time. For the first six repetitions they used the usual coordination of eye movements and steering; for drives 7--12 they were instructed to fixate on a small spot in the centre of the screen (centre gaze). Prevention of coordination in this way impaired their performance (drives 6 and 7 compared), dramatically increasing their time taken to complete the course, equivalent to slipping 19 places down the leader board in the actual rally stage. This indicates that the usual pattern of eye movements correlated with steering is crucial for driving performance. Further experiments are suggested to reveal whether any attentional demand associated with keeping the eyes still contributes to the loss in performance. PMID:15841399

  15. 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

  16. Assessment of Specific Characteristics of Abnormal General Movements: Does It Enhance the Prediction of Cerebral Palsy?

    ERIC Educational Resources Information Center

    Hamer, Elisa G.; Bos, Arend F.; Hadders-Algra, Mijna

    2011-01-01

    Aim: Abnormal general movements at around 3 months corrected age indicate a high risk of cerebral palsy (CP). We aimed to determine whether specific movement characteristics can improve the predictive power of definitely abnormal general movements. Method: Video recordings of 46 infants with definitely abnormal general movements at 9 to 13 weeks…

  17. Shrimps that pay attention: saccadic eye movements in stomatopod crustaceans.

    PubMed

    Marshall, N J; Land, M F; Cronin, T W

    2014-01-01

    Discovering that a shrimp can flick its eyes over to a fish and follow up by tracking it or flicking back to observe something else implies a 'primate-like' awareness of the immediate environment that we do not normally associate with crustaceans. For several reasons, stomatopods (mantis shrimp) do not fit the general mould of their subphylum, and here we add saccadic, acquisitional eye movements to their repertoire of unusual visual capabilities. Optically, their apposition compound eyes contain an area of heightened acuity, in some ways similar to the fovea of vertebrate eyes. Using rapid eye movements of up to several hundred degrees per second, objects of interest are placed under the scrutiny of this area. While other arthropod species, including insects and spiders, are known to possess and use acute zones in similar saccadic gaze relocations, stomatopods are the only crustacean known with such abilities. Differences among species exist, generally reflecting both the eye size and lifestyle of the animal, with the larger-eyed more sedentary species producing slower saccades than the smaller-eyed, more active species. Possessing the ability to rapidly look at and assess objects is ecologically important for mantis shrimps, as their lifestyle is, by any standards, fast, furious and deadly. PMID:24395969

  18. Shrimps that pay attention: saccadic eye movements in stomatopod crustaceans

    PubMed Central

    Marshall, N. J.; Land, M. F.; Cronin, T. W.

    2014-01-01

    Discovering that a shrimp can flick its eyes over to a fish and follow up by tracking it or flicking back to observe something else implies a ‘primate-like’ awareness of the immediate environment that we do not normally associate with crustaceans. For several reasons, stomatopods (mantis shrimp) do not fit the general mould of their subphylum, and here we add saccadic, acquisitional eye movements to their repertoire of unusual visual capabilities. Optically, their apposition compound eyes contain an area of heightened acuity, in some ways similar to the fovea of vertebrate eyes. Using rapid eye movements of up to several hundred degrees per second, objects of interest are placed under the scrutiny of this area. While other arthropod species, including insects and spiders, are known to possess and use acute zones in similar saccadic gaze relocations, stomatopods are the only crustacean known with such abilities. Differences among species exist, generally reflecting both the eye size and lifestyle of the animal, with the larger-eyed more sedentary species producing slower saccades than the smaller-eyed, more active species. Possessing the ability to rapidly look at and assess objects is ecologically important for mantis shrimps, as their lifestyle is, by any standards, fast, furious and deadly. PMID:24395969

  19. Reduced misinformation effects following saccadic bilateral eye movements.

    PubMed

    Parker, Andrew; Buckley, Sharon; Dagnall, Neil

    2009-02-01

    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 the depicted event and were then asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Finally, recognition memory was tested using the remember-know procedure. It was found that bilateral eye movements increased true memory for the event, increased recollection, and decreased the magnitude of the misinformation effect. The findings are discussed in terms of source monitoring, dual-process theories of memory and the potential neural foundations of such effects. PMID:18635303

  20. Combining EEG and eye tracking: identification, characterization, and correction of eye movement artifacts in electroencephalographic data.

    PubMed

    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

  1. EyeMap: a software system for visualizing and analyzing eye movement data in reading.

    PubMed

    Tang, Siliang; Reilly, Ronan G; Vorstius, Christian

    2012-06-01

    We have developed EyeMap, a freely available software system for visualizing and analyzing eye movement data specifically in the area of reading research. As compared with similar systems, including commercial ones, EyeMap has more advanced features for text stimulus presentation, interest area extraction, eye movement data visualization, and experimental variable calculation. It is unique in supporting binocular data analysis for unicode, proportional, and nonproportional fonts and spaced and unspaced scripts. Consequently, it is well suited for research on a wide range of writing systems. To date, it has been used with English, German, Thai, Korean, and Chinese. EyeMap is platform independent and can also work on mobile devices. An important contribution of the EyeMap project is a device-independent XML data format for describing data from a wide range of reading experiments. An online version of EyeMap allows researchers to analyze and visualize reading data through a standard Web browser. This facility could, for example, serve as a front-end for online eye movement data corpora. PMID:21994183

  2. Effects of aging on eye movements in the real world

    PubMed Central

    Dowiasch, Stefan; Marx, Svenja; Einhäuser, Wolfgang; Bremmer, Frank

    2015-01-01

    The effects of aging on eye movements are well studied in the laboratory. Increased saccade latencies or decreased smooth-pursuit gain are well established findings. The question remains whether these findings are influenced by the rather untypical environment of a laboratory; that is, whether or not they transfer to the real world. We measured 34 healthy participants between the age of 25 and 85 during two everyday tasks in the real world: (I) walking down a hallway with free gaze, (II) visual tracking of an earth-fixed object while walking straight-ahead. Eye movements were recorded with a mobile light-weight eye tracker, the EyeSeeCam (ESC). We find that age significantly influences saccade parameters. With increasing age, saccade frequency, amplitude, peak velocity, and mean velocity are reduced and the velocity/amplitude distribution as well as the velocity profile become less skewed. In contrast to laboratory results on smooth pursuit, we did not find a significant effect of age on tracking eye-movements in the real world. Taken together, age-related eye-movement changes as measured in the laboratory only partly resemble those in the real world. It is well-conceivable that in the real world additional sensory cues, such as head-movement or vestibular signals, may partially compensate for age-related effects, which, according to this view, would be specific to early motion processing. In any case, our results highlight the importance of validity for natural situations when studying the impact of aging on real-life performance. PMID:25713524

  3. Subjective awareness of abnormal involuntary movements in schizophrenia.

    PubMed

    Sandyk, R; Kay, S R; Awerbuch, G I

    1993-01-01

    A wide majority of schizophrenic patients with Tardive dyskinesia, a neurological disorder produced by chronic neuroleptic therapy, lack awareness of their involuntary movements. This by contrast to patients with Parkinsonism who usually are aware of their abnormal movements. In the following communication we present a series of studies which are aimed at providing further insight into the issue of awareness of involuntary movements in schizophrenic patients with tardive dyskinesia. In addition, we investigated whether edentulosness, which may be a risk factor for orofacial dyskinesias in the elderly, is also a risk factor for neuroleptic-induced orofacial dyskinesias. We found that: (a) one's awareness of involuntary movements is related to some but not all muscle groups, (b) tardive dyskinesia may be associated with a significant distress, (c) lack of awareness may be a feature of frontal lobe dysfunction in schizophrenia, (d) patients who lack awareness of their involuntary movements have a higher prevalence of pineal calcification, and (e) edentulosness, which is related to deficits in the orofacial sensorimotor system, increases the risk for neuroleptic-induced orofacial dyskinesias. PMID:7916006

  4. The pupillary light response reflects eye-movement preparation.

    PubMed

    Mathôt, Sebastiaan; van der Linden, Lotje; Grainger, Jonathan; Vitu, Françoise

    2015-02-01

    When the eyes are exposed to an increased influx of light, the pupils constrict. The pupillary light response (PLR) is traditionally believed to be purely reflexive and not susceptible to cognitive influences. In contrast to this traditional view, we report that preparation of a PLR occurs in parallel with preparation of a saccadic eye movement toward a bright (or dark) stimulus, even before the eyes set in motion. Participants fixated a central gray area and made a saccade toward a peripheral target. Using gaze-contingent display changes, we manipulated whether or not the brightness of the target background was the same during and after saccade preparation. More specifically, on some trials we changed the brightness of the target background during the saccade, thus dissociating the preparatory PLR (i.e., to the brightness of the target background before the saccade) from the regular PLR (i.e., to the brightness after the saccade). We show that preparation triggers a pupillary response to the brightness of a to-be-fixated target background already before the eyes have landed on it. We link our findings to the presaccadic shift of attention: The pupil prepares to adjust its size to the brightness of a to-be-fixated stimulus as soon as attention covertly shifts toward that stimulus. Our findings illustrate that the PLR is a dynamic movement that is tightly linked to visual attention and eye-movement preparation. PMID:25621584

  5. Eye Movement Measurement in Diagnostic Assessment of Disorders of Consciousness

    PubMed Central

    Ting, Windsor Kwan-Chun; Perez Velazquez, Jose Luis; Cusimano, Michael D.

    2014-01-01

    We review the literature to appraise the evidence supporting or disputing the use of eye movement measurement in disorders of consciousness (DOC) with low levels of arousal or awareness, such as minimally conscious state (MCS), vegetative state (VS), and coma for diagnostic and prognostic purposes. We will focus on the effectiveness of each technique in the diagnostic classification of these patients and the gradual trend in research from manual to computerized tracking methods. New tools have become available at clinicians’ disposal to assess eye movements with high spatial and temporal fidelity. The close relationship between eye movement generation and organic dysfunction in the brain allows these tools to be applied to the assessment of severe DOC as a unique supplementary toolset. We posit that eye tracking can improve clinical diagnostic precision for DOC, a key component of assessment that often dictates the course of clinical care in DOC patients. We see the emergence of long-term eye-tracking studies with seamless integration of technology in the future to improve the performance of clinical assessment in DOC. PMID:25120529

  6. Covert Anti-Compensatory Quick Eye Movements during Head Impulses

    PubMed Central

    Todd, Nicholas S.; Jahn, Klaus; Schneider, Erich; Lehnen, Nadine

    2014-01-01

    Background Catch-up saccades during passive head movements, which compensate for a deficient vestibulo-ocular reflex (VOR), are a well-known phenomenon. These quick eye movements are directed toward the target in the opposite direction of the head movement. Recently, quick eye movements in the direction of the head movement (covert anti-compensatory quick eye movements, CAQEM) were observed in older individuals. Here, we characterize these quick eye movements, their pathophysiology, and clinical relevance during head impulse testing (HIT). Methods Video head impulse test data from 266 patients of a tertiary vertigo center were retrospectively analyzed. Forty-three of these patients had been diagnosed with vestibular migraine, and 35 with Menière’s disease. Results CAQEM occurred in 38% of the patients. The mean CAQEM occurrence rate (per HIT trial) was 11±10% (mean±SD). Latency was 83±30 ms. CAQEM followed the saccade main sequence characteristics and were compensated by catch-up saccades in the opposite direction. Compensatory saccades did not lead to more false pathological clinical head impulse test assessments (specificity with CAQEM: 87%, and without: 85%). CAQEM on one side were associated with a lower VOR gain on the contralateral side (p<0.004) and helped distinguish Menière’s disease from vestibular migraine (p = 0.01). Conclusion CAQEM are a common phenomenon, most likely caused by a saccadic/quick phase mechanism due to gain asymmetries. They could help differentiate two of the most common causes of recurrent vertigo: vestibular migraine and Menière’s disease. PMID:24732783

  7. Perceptual Specificity Effects in Rereading: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Sheridan, Heather; Reingold, Eyal M.

    2012-01-01

    The present experiments examined perceptual specificity effects using a rereading paradigm. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either presenting the target word in the same distortion typography…

  8. Progress and Standardization in Eye Movement Work with Human Infants

    ERIC Educational Resources Information Center

    Haith, Marshall M.

    2004-01-01

    This article presents the author's comments on a set of articles representing an unusual collation of work by investigators from different parts of the world, using similar high-tech instrumentation and procedures to measure eye movements in infants who lie in a fairly constrained age range. Although the articles in this thematic collection share…

  9. Visual reinforcement shapes eye movements in visual search.

    PubMed

    Paeye, Céline; Schütz, Alexander C; Gegenfurtner, Karl R

    2016-08-01

    We use eye movements to gain information about our visual environment; this information can indirectly be used to affect the environment. Whereas eye movements are affected by explicit rewards such as points or money, it is not clear whether the information gained by finding a hidden target has a similar reward value. Here we tested whether finding a visual target can reinforce eye movements in visual search performed in a noise background, which conforms to natural scene statistics and contains a large number of possible target locations. First we tested whether presenting the target more often in one specific quadrant would modify eye movement search behavior. Surprisingly, participants did not learn to search for the target more often in high probability areas. Presumably, participants could not learn the reward structure of the environment. In two subsequent experiments we used a gaze-contingent display to gain full control over the reinforcement schedule. The target was presented more often after saccades into a specific quadrant or a specific direction. The proportions of saccades meeting the reinforcement criteria increased considerably, and participants matched their search behavior to the relative reinforcement rates of targets. Reinforcement learning seems to serve as the mechanism to optimize search behavior with respect to the statistics of the task. PMID:27559719

  10. Children's Eye Movements in Reading: A Commentary

    ERIC Educational Resources Information Center

    Rayner, Keith; Ardoin, Scott P.; Binder, Katherine S.

    2013-01-01

    are discussed. Specifically, the following topics are addressed: (1) basic methodological issues, (2) prior research findings on children's reading, (3) research that is missing in the literature regarding children's eye movements during reading, (4) applied…

  11. Eye Movements Reveal How Task Difficulty Moulds Visual Search

    ERIC Educational Resources Information Center

    Young, Angela H.; Hulleman, Johan

    2013-01-01

    In two experiments we investigated the relationship between eye movements and performance in visual search tasks of varying difficulty. Experiment 1 provided evidence that a single process is used for search among static and moving items. Moreover, we estimated the functional visual field (FVF) from the gaze coordinates and found that its size…

  12. 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…

  13. The Emergence of Frequency Effects in Eye Movements

    ERIC Educational Resources Information Center

    Vanyukov, Polina M.; Warren, Tessa; Wheeler, Mark E.; Reichle, Erik D.

    2012-01-01

    A visual search experiment employed strings of Landolt "C"s to examine how the gap size of and frequency of exposure to distractor strings affected eye movements. Increases in gap size were associated with shorter first-fixation durations, gaze durations, and total times, as well as fewer fixations. Importantly, both the number and duration of…

  14. Integration of retinal and extraretinal information across eye movements.

    PubMed

    Ostendorf, Florian; Dolan, Raymond J

    2015-01-01

    Visual perception is burdened with a highly discontinuous input stream arising from saccadic eye movements. For successful integration into a coherent representation, the visuomotor system needs to deal with these self-induced perceptual changes and distinguish them from external motion. Forward models are one way to solve this problem where the brain uses internal monitoring signals associated with oculomotor commands to predict the visual consequences of corresponding eye movements during active exploration. Visual scenes typically contain a rich structure of spatial relational information, providing additional cues that may help disambiguate self-induced from external changes of perceptual input. We reasoned that a weighted integration of these two inherently noisy sources of information should lead to better perceptual estimates. Volunteer subjects performed a simple perceptual decision on the apparent displacement of a visual target, jumping unpredictably in sync with a saccadic eye movement. In a critical test condition, the target was presented together with a flanker object, where perceptual decisions could take into account the spatial distance between target and flanker object. Here, precision was better compared to control conditions in which target displacements could only be estimated from either extraretinal or visual relational information alone. Our findings suggest that under natural conditions, integration of visual space across eye movements is based upon close to optimal integration of both retinal and extraretinal pieces of information. PMID:25602956

  15. Representing Syllable Information during Silent Reading: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Ashby, Jane; Rayner, Keith

    2004-01-01

    Two eye movement experiments investigated the nature of the phonological representations used in reading English. Each tested whether sublexical, syllable information is part of that representation. Target words with CV-initial syllables (DE.MAND) or CVC-initial syllables (LAN.TERN) were preceded by primes that exactly matched or mismatched their…

  16. Aetiological Factors in Dyslexia: I. Saccadic Eye Movement Control.

    ERIC Educational Resources Information Center

    Leisman, Gerald; Schwartz, Joddy

    1978-01-01

    A study examined the character of saccadic eye movement (as reflected by duration/amplitude and velocity/amplitude functions) in 20 dyslexic and 20 normal children (mean age 8.2 years) and 28 normal adults (mean age 26.2 years). (Author/PHR)

  17. Eye Movements Reveal Components of Flexible Reading Strategies.

    ERIC Educational Resources Information Center

    Shebilske, Wayne L.; Fisher, Dennis F.

    The eye movements of two college graduates were monitored in a study of flexible reading, which is defined as the ability to adjust one's rate and approach to reading according to the purpose of reading, the difficulty of the material, and one's knowledge of the subject matter. The subjects were told to read an excerpt from a tenth grade biology…

  18. Processing of Written Irony: An Eye Movement Study

    ERIC Educational Resources Information Center

    Kaakinen, Johanna K.; Olkoniemi, Henri; Kinnari, Taina; Hyönä, Jukka

    2014-01-01

    We examined processing of written irony by recording readers' eye movements while they read target phrases embedded either in ironic or non-ironic story context. After reading each story, participants responded to a text memory question and an inference question tapping into the understanding of the meaning of the target phrase. The results…

  19. Individual Differences in Impulsivity Predict Anticipatory Eye Movements

    PubMed Central

    Cirilli, Laetitia; de Timary, Philippe; Lefèvre, Phillipe; Missal, Marcus

    2011-01-01

    Impulsivity is the tendency to act without forethought. It is a personality trait commonly used in the diagnosis of many psychiatric diseases. In clinical practice, impulsivity is estimated using written questionnaires. However, answers to questions might be subject to personal biases and misinterpretations. In order to alleviate this problem, eye movements could be used to study differences in decision processes related to impulsivity. Therefore, we investigated correlations between impulsivity scores obtained with a questionnaire in healthy subjects and characteristics of their anticipatory eye movements in a simple smooth pursuit task. Healthy subjects were asked to answer the UPPS questionnaire (Urgency Premeditation Perseverance and Sensation seeking Impulsive Behavior scale), which distinguishes four independent dimensions of impulsivity: Urgency, lack of Premeditation, lack of Perseverance, and Sensation seeking. The same subjects took part in an oculomotor task that consisted of pursuing a target that moved in a predictable direction. This task reliably evoked anticipatory saccades and smooth eye movements. We found that eye movement characteristics such as latency and velocity were significantly correlated with UPPS scores. The specific correlations between distinct UPPS factors and oculomotor anticipation parameters support the validity of the UPPS construct and corroborate neurobiological explanations for impulsivity. We suggest that the oculomotor approach of impulsivity put forth in the present study could help bridge the gap between psychiatry and physiology. PMID:22046334

  20. Cognitive performance baseline measurement and eye movement performance measures

    NASA Astrophysics Data System (ADS)

    Viirre, Erik S.; Chase, Bradley; Tsai, Yi-Fang

    2005-05-01

    Personnel are often required to perform multiple simultaneous tasks at the limits of their cognitive capacity. In research surrounding cognitive performance resources for tasks during stress and high cognitive workload, one area of deficiency is measurement of individual differences. To determine the amount of attentional demand a stressor places on a subject, one must first know that all subjects are performing at the same level with the same amount of available capacity in the control condition. By equating the baselines of performance across all subjects ("baselining") we can control for differing amounts of performance capacity or attentional resources in each individual. For example, a given level of task performance without a time restriction may be equated across subjects to account for attentional resources. Training to a fixed level of proficiency with time limits might obliterate individual differences in mental resources. Eye movement parameters may serve as a real-time measure of attentional demand. In implementing a baselining technique to control for individual differences, eye movement behaviors will be associated with the true cognitive demands of task loading or other stressors. Using eye movement data as a proxy for attentional state, it may be possible to "close the loop" on the human-machine system, providing a means by which the system can adapt to the attentional state of the human operator. In our presentation, eye movement data will be shown with and without the benefit of the baselining technique. Experimental results will be discussed within the context of this theoretical framework.

  1. Eye Movements of Monkey Observers Viewing Vocalizing Conspecifics

    ERIC Educational Resources Information Center

    Ghazanfar, Asif A.; Nielsen, Kristina; Logothetis, Nikos K.

    2006-01-01

    Primates, including humans, communicate using facial expressions, vocalizations and often a combination of the two modalities. For humans, such bimodal integration is best exemplified by speech-reading--humans readily use facial cues to enhance speech comprehension, particularly in noisy environments. Studies of the eye movement patterns of human…

  2. Eye Movement Desensitization and Reprocessing: A Critical Analysis.

    ERIC Educational Resources Information Center

    Erwin, Terry McVannel

    Since Shapiro's introduction of Eye Movement Desensitization and Reprocessing (EMDR) in 1989, it has been a highly controversial therapeutic technique. Critical reviews of Shapiro's initial study have highlighted many methodological shortcomings in her work. And early empirical research that followed Shapiro's original study has been criticized…

  3. Semantic Evaluation of Syntactic Structure: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Frazier, Lyn; Carminati, Maria Nella; Cook, Anne E.; Majewski, Helen; Rayner, Keith

    2006-01-01

    An eye movement study of temporarily ambiguous closure sentences confirmed that the early closure penalty in a sentence like "While John hunted the frightened deer escaped" is larger for a simple past verb ("hunted") than for a past progressive verb ("was hunting"). The results can be explained by the observation that simple past tense verbs…

  4. Reading Spaced and Unspaced Chinese Text: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Bai, Xuejun; Yan, Guoli; Liversedge, Simon P.; Zang, Chuanli; Rayner, Keith

    2008-01-01

    Native Chinese readers' eye movements were monitored as they read text that did or did not demark word boundary information. In Experiment 1, sentences had 4 types of spacing: normal unspaced text, text with spaces between words, text with spaces between characters that yielded nonwords, and finally text with spaces between every character. The…

  5. Development of Text Reading in Japanese: An Eye Movement Study

    ERIC Educational Resources Information Center

    Jincho, Nobuyuki; Feng, Gary; Mazuka, Reiko

    2014-01-01

    This study examined age-group differences in eye movements among third-grade, fifth-grade, and adult Japanese readers. In Experiment 1, Japanese children, but not adults, showed a longer fixation time on logographic kanji words than on phonologically transparent hiragana words. Further, an age-group difference was found in the first fixation…

  6. Conceptual Change, Text Comprehension and Eye Movements during Reading

    ERIC Educational Resources Information Center

    Penttinen, Marjaana; Anto, Erkki; Mikkilä-Erdmann, Mirjamaija

    2013-01-01

    In the two studies presented in this article, we examine the interplay of conceptual change, text comprehension, and eye-movements during reading and develop and test methods suitable for such explorations. In studies 1 and 2, university students (N = 15 and 23) read a text on photosynthesis, explained their reading processes retrospectively cued…

  7. Eye movements during mental time travel follow a diagonal line.

    PubMed

    Hartmann, Matthias; Martarelli, Corinna S; Mast, Fred W; Stocker, Kurt

    2014-11-01

    Recent research showed that past events are associated with the back and left side, whereas future events are associated with the front and right side of space. These spatial-temporal associations have an impact on our sensorimotor system: thinking about one's past and future leads to subtle body sways in the sagittal dimension of space (Miles, Nind, & Macrae, 2010). In this study we investigated whether mental time travel leads to sensorimotor correlates in the horizontal dimension of space. Participants were asked to mentally displace themselves into the past or future while measuring their spontaneous eye movements on a blank screen. Eye gaze was directed more rightward and upward when thinking about the future than when thinking about the past. Our results provide further insight into the spatial nature of temporal thoughts, and show that not only body, but also eye movements follow a (diagonal) "time line" during mental time travel. PMID:25307523

  8. Absence of rapid eye movements during sleep in adult zebrafish.

    PubMed

    Árnason, B B; Þorsteinsson, H; Karlsson, K Æ

    2015-09-15

    Sleep is not a uniform phenomenon, but is organized in alternating, fundamentally different states, rapid eye movement sleep and non-rapid eye movement sleep. Zebrafish (Danio rerio) have recently emerged as an excellent model for sleep research. Zebrafish are well characterized in terms of development, neurobiology and genetics. Moreover, there are many experimental tools not easily applied in mammalian models that can be readily applied to zebrafish, making them a valuable additional animal model for sleep research. Sleep in zebrafish is defined behaviorally and exhibits the hallmarks of mammalian sleep (e.g. sleep homeostasis and pressure). To our knowledge no attempts have been made to discern if sleep in zebrafish entails alternations of REM-NREM sleep cycles which are critical for further development of the model. In the current experiment we quantify two key REM sleep components, rapid eye movements and respiratory rates, across sleep-wake cycles. We find no sleep-related rapid eye movements. During sleep respiratory rates, however, are reduced and become less regular, further establishing that the behavioral definition used truly captures a change in the fish's physiology. We thus fail to find evidence for REM-NREM sleep cycles in zebrafish but demonstrate a physiological change that occurs concomitantly with the previously defined behavioral state of sleep. We do not rule out that other phasic REM components (e.g. atonia, cardiac arrhythmias, myoclonic twitches or desynchronized EEG) are coherently expressed during sleep but we conclude that adult zebrafish do not have REM-sleep-related rapid eye movements. PMID:26003945

  9. Visual space is compressed in prefrontal cortex before eye movements.

    PubMed

    Zirnsak, Marc; Steinmetz, Nicholas A; Noudoost, Behrad; Xu, Kitty Z; Moore, Tirin

    2014-03-27

    We experience the visual world through a series of saccadic eye movements, each one shifting our gaze to bring objects of interest to the fovea for further processing. Although such movements lead to frequent and substantial displacements of the retinal image, these displacements go unnoticed. It is widely assumed that a primary mechanism underlying this apparent stability is an anticipatory shifting of visual receptive fields (RFs) from their presaccadic to their postsaccadic locations before movement onset. Evidence of this predictive 'remapping' of RFs has been particularly apparent within brain structures involved in gaze control. However, critically absent among that evidence are detailed measurements of visual RFs before movement onset. Here we show that during saccade preparation, rather than remap, RFs of neurons in a prefrontal gaze control area massively converge towards the saccadic target. We mapped the visual RFs of prefrontal neurons during stable fixation and immediately before the onset of eye movements, using multi-electrode recordings in monkeys. Following movements from an initial fixation point to a target, RFs remained stationary in retinocentric space. However, in the period immediately before movement onset, RFs shifted by as much as 18 degrees of visual angle, and converged towards the target location. This convergence resulted in a threefold increase in the proportion of RFs responding to stimuli near the target region. In addition, like in human observers, the population of prefrontal neurons grossly mislocalized presaccadic stimuli as being closer to the target. Our results show that RF shifts do not predict the retinal displacements due to saccades, but instead reflect the overriding perception of target space during eye movements. PMID:24670771

  10. Template aging in eye movement-driven biometrics

    NASA Astrophysics Data System (ADS)

    Komogortsev, Oleg V.; Holland, Corey D.; Karpov, Alex

    2014-05-01

    This paper presents a template aging study of eye movement biometrics, considering three distinct biometric techniques on multiple stimuli and eye tracking systems. Short-to-midterm aging effects are examined over two-weeks, on a highresolution eye tracking system, and seven-months, on a low-resolution eye tracking system. We find that, in all cases, aging effects are evident as early as two weeks after initial template collection, with an average 28% (±19%) increase in equal error rates and 34% (±12%) reduction in rank-1 identification rates. At seven months, we observe an average 18% (±8%) increase in equal error rates and 44% (±20%) reduction in rank-1 identification rates. The comparative results at two-weeks and seven-months suggests that there is little difference in aging effects between the two intervals; however, whether the rate of decay increases more drastically in the long-term remains to be seen.

  11. CUE: counterfeit-resistant usable eye movement-based authentication via oculomotor plant characteristics and complex eye movement patterns

    NASA Astrophysics Data System (ADS)

    Komogortsev, Oleg V.; Karpov, Alexey; Holland, Corey D.

    2012-06-01

    The widespread use of computers throughout modern society introduces the necessity for usable and counterfeit-resistant authentication methods to ensure secure access to personal resources such as bank accounts, e-mail, and social media. Current authentication methods require tedious memorization of lengthy pass phrases, are often prone to shouldersurfing, and may be easily replicated (either by counterfeiting parts of the human body or by guessing an authentication token based on readily available information). This paper describes preliminary work toward a counterfeit-resistant usable eye movement-based (CUE) authentication method. CUE does not require any passwords (improving the memorability aspect of the authentication system), and aims to provide high resistance to spoofing and shoulder-surfing by employing the combined biometric capabilities of two behavioral biometric traits: 1) oculomotor plant characteristics (OPC) which represent the internal, non-visible, anatomical structure of the eye; 2) complex eye movement patterns (CEM) which represent the strategies employed by the brain to guide visual attention. Both OPC and CEM are extracted from the eye movement signal provided by an eye tracking system. Preliminary results indicate that the fusion of OPC and CEM traits is capable of providing a 30% reduction in authentication error when compared to the authentication accuracy of individual traits.

  12. Eye movements between saccades: Measuring ocular drift and tremor.

    PubMed

    Ko, Hee-Kyoung; Snodderly, D Max; Poletti, Martina

    2016-05-01

    Intersaccadic periods of fixation are characterized by incessant retinal motion due to small eye movements. While these movements are often disregarded as noise, the temporal modulations they introduce to retinal receptors are significant. However, analysis of these input modulations is challenging because the intersaccadic eye motion is close to the resolution limits of most eyetrackers, including widespread pupil-based video systems. Here, we analyzed in depth the limits of two high-precision eyetrackers, the Dual-Purkinje Image and the scleral search coil, and compared the intersaccadic eye movements of humans to those of a non-human primate. By means of a model eye we determined that the resolution of both techniques is sufficient to reliably measure intersaccadic ocular activity up to approximately 80Hz. Our results show that the characteristics of ocular drift are remarkably similar in the two species; a clear deviation from a scale-invariant spectrum occurs in the range between 50 and 100Hz, generally attributed to ocular tremor, leading to intersaccadic retinal speeds as high as 1.5deg/s. The amplitude of this deviation differs on the two axes of motion. In addition to our experimental observations, we suggest basic guidelines to evaluate the performance of eyetrackers and to optimize experimental conditions for the measurement of ocular drift and tremor. PMID:27068415

  13. Eye movement and vestibular dysfunction in mitochondrial A3243G mutation.

    PubMed

    Kim, Sung-Hee; Akbarkhodjaeva, Ziyoda Abdulkhaevna; Jung, Ileok; Kim, Ji-Soo

    2016-07-01

    Studying eye movements and vestibular function would provide insights into brain networks that are vulnerable in mitochondrial disorders. We sought eye movement and vestibular abnormalities in three Korean patients with a mitochondrial A3243G point mutation. The patients suffered from vertigo and imbalance during the stroke-like and seizure episodes from lesions involving the posterior cerebral cortex, which were accompanied by bilateral saccadic hypermetria and horizontal gaze-evoked nystagmus. Furthermore, two patients showed bilateral impairments of the vestibulo-ocular reflex during head impulses for the horizontal and posterior canals on both sides in the absence of caloric paresis. Cerebellar atrophy was prominent on MRIs in two patients and was less marked in the other patient. These findings imply that the cerebellum is susceptible to neuronal energy deficiency due to mitochondrial A3243G point mutation. PMID:27075643

  14. Development of an eyewear to measure eye and body movements.

    PubMed

    Kanoh, S; Ichi-Nohe, S; Shioya, S; Inoue, K; Kawashima, R

    2015-08-01

    To enable precise detection of mental and physical states of users in a daily life, we have been developing an eyewear to measure eye and body movement in a unrestricted way. The horizontal and vertical EOG (electrooculogram) signals are measured and amplified with three metal dry electrodes placed near nasion and both sides of rhinion, of which positions correspond to the bridge and nose pads of eyewear, respectively. The user's mental states like drowsiness, sleepiness, fatigue, or interest to objects can be identified by the movements and blinking of the eyes extracted from the measured EOG. And the six-axis motion sensor (three-axis accelerometer and three-axis gyroscope) mounted in the eyewear measures the body motion. As the sensor located near the head is on the body axis, this eyewear is suitable to measure user's movement or shift of center of gravity during physical exercise with a high precision. The measured signals are used to extract various events of eye and body movement by the mounted microcontroller chip, or can be transmitted to the external devices via Bluetooth communication. This device can enable you to look into "yourself", as well as outer scenes. In this presentation, the outline of the eyewear is introduced and some possible applications are shown. PMID:26736744

  15. Scanning eye movements made when viewing film: preliminary observations.

    PubMed

    Tosi, V; Mecacci, L; Pasquali, E

    1997-11-01

    Eye movements were recorded in 10 adult subjects during the viewing of fiction and nonfiction films. Individual differences in scan paths for fiction films were found to be relatively small. Generally, eyes concentrated on the screen center when looking at characters and objects in rapid motion. Scan paths through the screen were observed in special cases, for example, in the case of a dialogue between two characters. No differences emerged in scan paths for the same clip presented in black-and-white and color versions. Results are relevant for both filmmaking and research on perceptual and cognitive strategies involved in processing motion pictures. PMID:9522254

  16. Abnormal head movement in a patient with tuberculous meningitis.

    PubMed

    Garg, Ravindra Kumar; Singh, Sunil Kumar; Malhotra, Hardeep Singh; Singh, Maneesh Kumar

    2012-01-01

    The bobble-head doll syndrome is characterised by abnormal head movements. These head movements are usually 'yes-yes' (up and down) type; rarely, head movements are 'no-no' (side-to-side) type. Commonly described causes of the bobble-head doll syndrome include third ventricular tumours, suprasellar arachnoid cysts, aqueductal stenosis and other lesions in the region of the third ventricle of the brain. We report a case of tuberculous meningitis with hydrocephalus; in this patient bobble-head doll syndrome developed following external ventricular drainage. In our patient, placement of intraventricular drain led to massive dilatation of the frontal horn of the left lateral ventricle because of blocked foramina of Monro on the left side. The bobble-head doll syndrome, presumably, developed because of the pressure effect of the dilated third ventricle on the dorsomedial nucleus of the thalamus, red nucleus and dentatorubrothalamic pathways. We think that distortion of the third ventricle was responsible for the impairment of the functions of all these structures. PMID:23035162

  17. Extending the E-Z Reader Model of Eye Movement Control to Chinese Readers

    ERIC Educational Resources Information Center

    Rayner, Keith; Li, Xingshan; Pollatsek, Alexander

    2007-01-01

    Chinese readers' eye movements were simulated in the context of the E-Z Reader model, which was developed to account for the eye movements of readers of English. Despite obvious differences between English and Chinese, the model did a fairly good job of simulating the eye movements of Chinese readers. The successful simulation suggests that the…

  18. 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…

  19. Postural sway and the frequency of horizontal eye movements.

    PubMed

    Stoffregen, Thomas A; Bardy, Benoît G; Bonnet, Céderick T; Hove, Philip; Oullier, Olivier

    2007-01-01

    In two experiments, participants were asked to shift gaze to follow horizontal target oscillation to allow us to investigate relations between eye movements and postural dynamics. Postural sway variability was reduced during target oscillation when compared to sway while viewing a stationary target. The influence of target oscillation on sway was independent of target oscillation frequency. Similar results were obtained with measurements of the center of pressure (Experiment 1) and the displacement of body segments (Experiment 2). The overall results are not consistent with the view that eye movements and postural control compete for limited central processing resources. The results are consistent with the thesis of a functional integration of postural control with visual performance. PMID:17392569

  20. Computations underlying the visuomotor transformation for smooth pursuit eye movements

    PubMed Central

    Murdison, T. Scott; Leclercq, Guillaume; Lefèvre, Philippe

    2014-01-01

    Smooth pursuit eye movements are driven by retinal motion and enable us to view moving targets with high acuity. Complicating the generation of these movements is the fact that different eye and head rotations can produce different retinal stimuli but giving rise to identical smooth pursuit trajectories. However, because our eyes accurately pursue targets regardless of eye and head orientation (Blohm G, Lefèvre P. J Neurophysiol 104: 2103–2115, 2010), the brain must somehow take these signals into account. To learn about the neural mechanisms potentially underlying this visual-to-motor transformation, we trained a physiologically inspired neural network model to combine two-dimensional (2D) retinal motion signals with three-dimensional (3D) eye and head orientation and velocity signals to generate a spatially correct 3D pursuit command. We then simulated conditions of 1) head roll-induced ocular counterroll, 2) oblique gaze-induced retinal rotations, 3) eccentric gazes (invoking the half-angle rule), and 4) optokinetic nystagmus to investigate how units in the intermediate layers of the network accounted for different 3D constraints. Simultaneously, we simulated electrophysiological recordings (visual and motor tunings) and microstimulation experiments to quantify the reference frames of signals at each processing stage. We found a gradual retinal-to-intermediate-to-spatial feedforward transformation through the hidden layers. Our model is the first to describe the general 3D transformation for smooth pursuit mediated by eye- and head-dependent gain modulation. Based on several testable experimental predictions, our model provides a mechanism by which the brain could perform the 3D visuomotor transformation for smooth pursuit. PMID:25475344

  1. Computations underlying the visuomotor transformation for smooth pursuit eye movements.

    PubMed

    Murdison, T Scott; Leclercq, Guillaume; Lefèvre, Philippe; Blohm, Gunnar

    2015-03-01

    Smooth pursuit eye movements are driven by retinal motion and enable us to view moving targets with high acuity. Complicating the generation of these movements is the fact that different eye and head rotations can produce different retinal stimuli but giving rise to identical smooth pursuit trajectories. However, because our eyes accurately pursue targets regardless of eye and head orientation (Blohm G, Lefèvre P. J Neurophysiol 104: 2103-2115, 2010), the brain must somehow take these signals into account. To learn about the neural mechanisms potentially underlying this visual-to-motor transformation, we trained a physiologically inspired neural network model to combine two-dimensional (2D) retinal motion signals with three-dimensional (3D) eye and head orientation and velocity signals to generate a spatially correct 3D pursuit command. We then simulated conditions of 1) head roll-induced ocular counterroll, 2) oblique gaze-induced retinal rotations, 3) eccentric gazes (invoking the half-angle rule), and 4) optokinetic nystagmus to investigate how units in the intermediate layers of the network accounted for different 3D constraints. Simultaneously, we simulated electrophysiological recordings (visual and motor tunings) and microstimulation experiments to quantify the reference frames of signals at each processing stage. We found a gradual retinal-to-intermediate-to-spatial feedforward transformation through the hidden layers. Our model is the first to describe the general 3D transformation for smooth pursuit mediated by eye- and head-dependent gain modulation. Based on several testable experimental predictions, our model provides a mechanism by which the brain could perform the 3D visuomotor transformation for smooth pursuit. PMID:25475344

  2. Eye movements due to linear accelerations in the rabbit.

    PubMed Central

    Baarsma, E A; Collewijn, H

    1975-01-01

    1. Compensatory vertical or torsional eye movements of rabbits caused by linear accelerations along the transverse or sagittal axis were measured. Sinusoidal accelerations (parallel swing) in a frequency range of 0-068--1-22 Hz and acceleration steps (linear track) of 0-02--0-11 g were applied. 2. On the parallel swing, properties of the maculo-ocular reflexes were similar for transverse and sagittal acceleration. Gain (rotation of eye/rotation of the resultant linear vector) proved to be very low: about 0-1 for 0-3 Hz and smaller than 0-01 for frequencies above 1-0 Hz. The decrease in gain was accompanied by an increase in phase lag to about 180degrees. No non-linearity was revealed by the use of different amplitudes (10--30 cm). 3. On the linear track, eye deviation after an acceleration step took many seconds to develop fully. Gain increased with time and was about 0-65 after 5 sec. 4. The results indicate that the responses of the otoliths, as reflected in maculo-ocular reactions, are very slow. Fluctuations in the direction of gravity seem to be averaged over several seconds by the system. This may explain that erratic linear accelerations(frequency greater than 1 Hz) during locomotion or transport do not lead to eye movements or disorientation. PMID:1127609

  3. Eye movements during listening reveal spontaneous grammatical processing

    PubMed Central

    Huette, Stephanie; Winter, Bodo; Matlock, Teenie; Ardell, David H.; Spivey, Michael

    2014-01-01

    Recent research using eye-tracking typically relies on constrained visual contexts in particular goal-oriented contexts, viewing a small array of objects on a computer screen and performing some overt decision or identification. Eyetracking paradigms that use pictures as a measure of word or sentence comprehension are sometimes touted as ecologically invalid because pictures and explicit tasks are not always present during language comprehension. This study compared the comprehension of sentences with two different grammatical forms: the past progressive (e.g., was walking), which emphasizes the ongoing nature of actions, and the simple past (e.g., walked), which emphasizes the end-state of an action. The results showed that the distribution and timing of eye movements mirrors the underlying conceptual structure of this linguistic difference in the absence of any visual stimuli or task constraint: Fixations were shorter and saccades were more dispersed across the screen, as if thinking about more dynamic events when listening to the past progressive stories. Thus, eye movement data suggest that visual inputs or an explicit task are unnecessary to solicit analog representations of features such as movement, that could be a key perceptual component to grammatical comprehension. PMID:24904450

  4. Prominent reflexive eye-movement orienting associated with deafness.

    PubMed

    Bottari, Davide; Valsecchi, Matteo; Pavani, Francesco

    2012-01-01

    Profound deafness affects orienting of visual attention. Until now, research focused exclusively on covert attentional orienting, neglecting whether overt oculomotor behavior may also change in deaf people. Here we used the pro- and anti-saccade task to examine the relative contribution of reflexive and voluntary eye-movement control in profoundly deaf and hearing individuals. We observed a behavioral facilitation in reflexive compared to voluntary eye movements, indexed by faster saccade latencies and smaller error rates in pro- than anti-saccade trials, which was substantially larger in deaf than hearing participants. This provides the first evidence of plastic changes related to deafness in overt oculomotor behavior, and constitutes an ecologically relevant parallel to the modulations attributed to deafness in covert attention orienting. Our findings also have implications for designers of real and virtual environments for deaf people and reveal that experiments on deaf visual abilities must not ignore the prominent reflexive eye-movement orienting in this sensory-deprived population. PMID:24168645

  5. Eye movement prediction and variability on natural video data sets

    PubMed Central

    Dorr, Michael; Vig, Eleonora; Barth, Erhardt

    2012-01-01

    We here study the predictability of eye movements when viewing high-resolution natural videos. We use three recently published gaze data sets that contain a wide range of footage, from scenes of almost still-life character to professionally made, fast-paced advertisements and movie trailers. Inter-subject gaze variability differs significantly between data sets, with variability being lowest for the professional movies. We then evaluate three state-of-the-art saliency models on these data sets. A model that is based on the invariants of the structure tensor and that combines very generic, sparse video representations with machine learning techniques outperforms the two reference models; performance is further improved for two data sets when the model is extended to a perceptually inspired colour space. Finally, a combined analysis of gaze variability and predictability shows that eye movements on the professionally made movies are the most coherent (due to implicit gaze-guidance strategies of the movie directors), yet the least predictable (presumably due to the frequent cuts). Our results highlight the need for standardized benchmarks to comparatively evaluate eye movement prediction algorithms. PMID:22844203

  6. Word length effects on novel words: evidence from eye movements.

    PubMed

    Lowell, Randy; Morris, Robin K

    2014-01-01

    The present study investigated the effects of word length on eye movement behavior during initial processing of novel words while reading. Adult skilled readers' eye movements were monitored as they read novel or known target words in sentence frames with neutral context preceding the target word. Comparable word length effects on all single-fixation measures for novel and known words suggested that both types of words were subject to similar initial encoding strategies. The impact of the absence of an existing lexical entry emerged in multiple first-pass fixation measures in the form of interactions between word length (long and short) and word type (novel and known). Specifically, readers spent significantly more first-pass time refixating long novel targets than short novel targets; however, the first-pass time spent refixating known controls did not differ as a function of length. Implications of these findings for models of eye movement control while reading, as well as for vocabulary acquisition in reading, are discussed. PMID:24092359

  7. Learning on Multiple Timescales in Smooth Pursuit Eye Movements

    PubMed Central

    Yang, Yan

    2010-01-01

    We commonly think of motor learning as a gradual process that makes small, adaptive steps in a consistent direction. We now report evidence that learning in pursuit eye movements could start with large, transient short-term alterations that stoke a more gradual long-term process. Monkeys tracked a target that started moving horizontally or vertically. After 250 ms of motion had produced a preinstruction eye velocity close to target velocity, an orthogonal component of target motion created an instructive change in target direction that was randomly in one of the two directions along the orthogonal axis. The preinstruction eye velocity in each trial expressed single-trial learning as a bias toward the direction of the instruction in the prior trial. The single-trial learning was forgotten within 4 to 10 s. Two observations implied that single-trial learning was not simply cognitive anticipation. First, the magnitude of the trial-over-trial change in eye velocity depended on the ongoing eye velocity at the time of the instruction in the prior trial. Single-trial learning was negligible if the prior trial had provided a well-timed cue without evoking any preinstruction eye velocity. Second, regular alternation of the direction of the instructive target motion caused reactive rather than anticipatory trial-over-trial changes in eye velocity. Humans showed very different responses that appeared to be based on cognitive anticipation rather than learning. We suggest that single-trial learning results from a low-level learning mechanism and may be a necessary prerequisite for longer-term modifications that are more permanent. PMID:20884765

  8. Effects of voluntary eye movement and convergence on the binocular appreciation of depth.

    NASA Technical Reports Server (NTRS)

    Foley, J. M.; Richards, W.

    1972-01-01

    Scaling techniques were employed to establish the relation between perceived distance ratio and physical distance ratio. Measurements were made both with and without free eye movement and under two states of convergence. The results were confirmed using a matching technique. With free eye movement, the perceived ratio is a monotonic increasing function of the physical ratio. Without eye movement, the perceived ratio generally increases, then decreases, as the physical ratio increases. For a given physical ratio, perceived distance ratio is less in the absence of voluntary eye movements. Convergence produces depth micropsia when eye movements are permitted, but not in their absence.

  9. Destabilizing effects of visual environment motions simulating eye movements or head movements

    NASA Technical Reports Server (NTRS)

    White, Keith D.; Shuman, D.; Krantz, J. H.; Woods, C. B.; Kuntz, L. A.

    1991-01-01

    In the present paper, we explore effects on the human of exposure to a visual virtual environment which has been enslaved to simulate the human user's head movements or eye movements. Specifically, we have studied the capacity of our experimental subjects to maintain stable spatial orientation in the context of moving their entire visible surroundings by using the parameters of the subjects' natural movements. Our index of the subjects' spatial orientation was the extent of involuntary sways of the body while attempting to stand still, as measured by translations and rotations of the head. We also observed, informally, their symptoms of motion sickness.

  10. NASA supporting studies for microgravity research on eye movements

    NASA Technical Reports Server (NTRS)

    Cohen, Bernard

    1990-01-01

    The purpose of the work on this project was to provide support for ground-based studies on the effects of gravity on eye movements. The effects of microgravity on the optokinetic eye movements of humans are investigated. OKN was induced by having subjects watch 3.3 deg stripes moving at 35 deg/s for 45 s in a binocular, head-fixed apparatus. The field (hor., 88 deg; vert., 72 deg), was rotated about axes that were upright or tilted 45 deg or 90 deg. The head was upright or tilted 45 deg on the body. Head-horizontal (yaw axis) and head-vertical (pitch axis) components of OKN were recorded with electro-oculography (EOG). Slow phase velocity vectors were determined relative to gravity. With the head upright, the axis of eye rotation during yaw axis OKN was coincident with the stimulus axis and the spatial vertical. With the head tilted 45 deg on the body, a persistent vertical component of eye velocity developed during yaw axis stimulation, and there was an average shift of the axis of eye rotation toward the spatial vertical of approximately 18 deg in six subjects. During oblique optokinetic stimulation with the head upright, the axis of eye rotation shifted 12 deg toward the spatial vertical. When the head was tilted, the axis of eye rotation rotated to the other side of the spatial vertical by 5.4 deg during the same oblique stimulation. This counter-rotation of the axis of eye rotation is similar to the 'Muller (E) effect', in which the perception of the upright counter-rotates to the opposite side of the spatial vertical when subjects are tilted in darkness. The data were simulated by a model of OKN. Despite the short OKAN time constants, strong horizontal to vertical cross-coupling was produced if the horizontal and vertical time constants were in proper ratio, and there was no suppression of nystagmus orthogonal to the stimulus direction. This shows that the spatial orientation of OKN can be due to a restructuring of the system matrix of velocity storage as a

  11. EFFECTS OF MILD TO MODERATE SEDATION ON SACCADIC EYE MOVEMENTS

    PubMed Central

    Busettini, C.; Frölich, M. A.

    2014-01-01

    Sedatives alter the metrics of saccadic eye movements. If these effects are nonspecific consequences of sedation, like drowsiness and loss of attention to the task, or differ between sedatives is still unresolved. A placebo-controlled multi-step infusion of one of three sedatives, propofol or midazolam, both GABA-A agonists, or dexmedetedomidine, an α2-adrenergic agonist, was adopted to compare the effects of these three drugs in exactly the same experimental conditions. 60 healthy human volunteers, randomly divided in 4 groups, participated in the study. Each infusion step, delivered by a computer-controlled infusion pump, lasted 20 min. During the last 10 min of each step, the subject executed a saccadic task. Target concentration was doubled at each step. This block was repeated until the subject was too sedated to continue or for a maximum of 6 blocks. Subjects were unaware which infusion they were receiving. A video eye tracker was used to record the movements of the right eye. Saccadic parameters were modeled as a function of block number, estimated sedative plasma concentration, and subjective evaluation of sedation. Propofol and midazolam had strong effects on the dynamics and latency of the saccades. Midazolam, and to a less extent, propofol, caused saccades to become increasingly hypometric. Dexmedetedomidine had less impact on saccadic metrics and presented no changes in saccadic gain. Suppression of the sympathetic system associated with dexmedetomidine has different effects on eye movements from the increased activity of the inhibitory GABA-A receptors by propofol and midazolam even when the subjects reported similar sedation level. PMID:25026096

  12. The eye of the beholder: Can patterns in eye movement reveal aptitudes for spatial reasoning?

    PubMed

    Roach, Victoria A; Fraser, Graham M; Kryklywy, James H; Mitchell, Derek G V; Wilson, Timothy D

    2016-07-01

    Mental rotation ability (MRA) is linked to academic success in the spatially complex Science, Technology, Engineering, Medicine, and Mathematics (STEMM) disciplines, and anatomical sciences. Mental rotation literature suggests that MRA may manifest in the movement of the eyes. Quantification of eye movement data may serve to distinguish MRA across individuals, and serve as a consideration when designing visualizations for instruction. It is hypothesized that high-MRA individuals will demonstrate fewer eye fixations, conduct shorter average fixation durations (AFD), and demonstrate shorter response times, than low-MRA individuals. Additionally, individuals with different levels of MRA will attend to different features of the block-figures presented in the electronic mental rotations test (EMRT). All participants (n = 23) completed the EMRT while metrics of eye movement were collected. The test required participants view pairs of three-dimensional (3D) shapes, and identify if the pair is rotated but identical, or two different structures. Temporal analysis revealed no significant correlations between response time, average fixation durations, or number of fixations and mental rotation ability. Further analysis of within-participant variability yielded a significant correlation for response time variability, but no correlation between AFD variability and variability in the number of fixations. Additional analysis of salience revealed that during problem solving, individuals of differing MRA attended to different features of the block images; suggesting that eye movements directed at salient features may contribute to differences in mental rotations ability, and may ultimately serve to predict success in anatomy. Anat Sci Educ 9: 357-366. © 2015 American Association of Anatomists. PMID:26599398

  13. What's on TV? Detecting age-related neurodegenerative eye disease using eye movement scanpaths

    PubMed Central

    Crabb, David P.; Smith, Nicholas D.; Zhu, Haogang

    2014-01-01

    Purpose: We test the hypothesis that age-related neurodegenerative eye disease can be detected by examining patterns of eye movement recorded whilst a person naturally watches a movie. Methods: Thirty-two elderly people with healthy vision (median age: 70, interquartile range [IQR] 64–75 years) and 44 patients with a clinical diagnosis of glaucoma (median age: 69, IQR 63–77 years) had standard vision examinations including automated perimetry. Disease severity was measured using a standard clinical measure (visual field mean deviation; MD). All study participants viewed three unmodified TV and film clips on a computer set up incorporating the Eyelink 1000 eyetracker (SR Research, Ontario, Canada). Eye movement scanpaths were plotted using novel methods that first filtered the data and then generated saccade density maps. Maps were then subjected to a feature extraction analysis using kernel principal component analysis (KPCA). Features from the KPCA were then classified using a standard machine based classifier trained and tested by a 10-fold cross validation which was repeated 100 times to estimate the confidence interval (CI) of classification sensitivity and specificity. Results: Patients had a range of disease severity from early to advanced (median [IQR] right eye and left eye MD was −7 [−13 to −5] dB and −9 [−15 to −4] dB, respectively). Average sensitivity for correctly identifying a glaucoma patient at a fixed specificity of 90% was 79% (95% CI: 58–86%). The area under the Receiver Operating Characteristic curve was 0.84 (95% CI: 0.82–0.87). Conclusions: Huge data from scanpaths of eye movements recorded whilst people freely watch TV type films can be processed into maps that contain a signature of vision loss. In this proof of principle study we have demonstrated that a group of patients with age-related neurodegenerative eye disease can be reasonably well separated from a group of healthy peers by considering these eye movement

  14. Eye Movements Index Implicit Memory Expression in Fear Conditioning

    PubMed Central

    Hopkins, Lauren S.; Schultz, Douglas H.; Hannula, Deborah E.; Helmstetter, Fred J.

    2015-01-01

    The role of contingency awareness in simple associative learning experiments with human participants is currently debated. Since prior work suggests that eye movements can index mnemonic processes that occur without awareness, we used eye tracking to better understand the role of awareness in learning aversive Pavlovian conditioning. A complex real-world scene containing four embedded household items was presented to participants while skin conductance, eye movements, and pupil size were recorded. One item embedded in the scene served as the conditional stimulus (CS). One exemplar of that item (e.g. a white pot) was paired with shock 100 percent of the time (CS+) while a second exemplar (e.g. a gray pot) was never paired with shock (CS-). The remaining items were paired with shock on half of the trials. Participants rated their expectation of receiving a shock during each trial, and these expectancy ratings were used to identify when (i.e. on what trial) each participant became aware of the programmed contingencies. Disproportionate viewing of the CS was found both before and after explicit contingency awareness, and patterns of viewing distinguished the CS+ from the CS-. These observations are consistent with “dual process” models of fear conditioning, as they indicate that learning can be expressed in patterns of viewing prior to explicit contingency awareness. PMID:26562298

  15. Eye Movements Index Implicit Memory Expression in Fear Conditioning.

    PubMed

    Hopkins, Lauren S; Schultz, Douglas H; Hannula, Deborah E; Helmstetter, Fred J

    2015-01-01

    The role of contingency awareness in simple associative learning experiments with human participants is currently debated. Since prior work suggests that eye movements can index mnemonic processes that occur without awareness, we used eye tracking to better understand the role of awareness in learning aversive Pavlovian conditioning. A complex real-world scene containing four embedded household items was presented to participants while skin conductance, eye movements, and pupil size were recorded. One item embedded in the scene served as the conditional stimulus (CS). One exemplar of that item (e.g. a white pot) was paired with shock 100 percent of the time (CS+) while a second exemplar (e.g. a gray pot) was never paired with shock (CS-). The remaining items were paired with shock on half of the trials. Participants rated their expectation of receiving a shock during each trial, and these expectancy ratings were used to identify when (i.e. on what trial) each participant became aware of the programmed contingencies. Disproportionate viewing of the CS was found both before and after explicit contingency awareness, and patterns of viewing distinguished the CS+ from the CS-. These observations are consistent with "dual process" models of fear conditioning, as they indicate that learning can be expressed in patterns of viewing prior to explicit contingency awareness. PMID:26562298

  16. Flexible timing of eye movements when catching a ball.

    PubMed

    López-Moliner, Joan; Brenner, Eli

    2016-01-01

    In ball games, one cannot direct ones gaze at the ball all the time because one must also judge other aspects of the game, such as other players' positions. We wanted to know whether there are times at which obtaining information about the ball is particularly beneficial for catching it. We recently found that people could catch successfully if they saw any part of the ball's flight except the very end, when sensory-motor delays make it impossible to use new information. Nevertheless, there may be a preferred time to see the ball. We examined when six catchers would choose to look at the ball if they had to both catch the ball and find out what to do with it while the ball was approaching. A catcher and a thrower continuously threw a ball back and forth. We recorded their hand movements, the catcher's eye movements, and the ball's path. While the ball was approaching the catcher, information was provided on a screen about how the catcher should throw the ball back to the thrower (its peak height). This information disappeared just before the catcher caught the ball. Initially there was a slight tendency to look at the ball before looking at the screen but, later, most catchers tended to look at the screen before looking at the ball. Rather than being particularly eager to see the ball at a certain time, people appear to adjust their eye movements to the combined requirements of the task. PMID:26982371

  17. Lexical processes and eye movements in neglect dyslexia.

    PubMed

    di Pellegrino, G; Làdavas, E; Galletti, C

    Neglect dyslexia is a disturbance in the allocation of spatial attention over a letter string following unilateral brain damage. Patients with this condition may fail to read letters on the contralesional side of an orthographic string. In some of these cases, reading is better with words than with non-words. This word superiority effect has received a variety of explanations that differ, among other things, with regard to the spatial distribution of attention across the letter string during reading. The primary goal of the present study was to explore the interaction between attention and lexical processes by recording eye movements in a patient (F.C.) with severe left neglect dyslexia who was required to read isolated word and non-word stimuli of various length. F.C.'s ocular exploration of orthographic stimuli was highly sensitive to the lexical status of the letter string. We found that: (1) the location to which F.C. directed his initial saccade (obtained approximately 230 ms post-stimulus onset) differed between word and non-word stimuli; (2) the patient spent a greater amount of time fixating the contralesional side of word than non-word strings. Moreover, we also found that F.C. failed to identify the left letters of a string despite having fixated them, thus showing a clear dissociation between eye movement responses and conscious access to orthographic stimuli. Our data suggest the existence of multiple interactions between lexical, attentional and eye movement systems that occur from very initial stages of visual word recognition. PMID:12118151

  18. A Preformed Scleral Search Coil for Measuring Mouse Eye Movements

    PubMed Central

    Kaneko, Chris R. S.; Rosenfeld, Sam; Fontaine, Ethan; Markov, Alex; Phillips, James O.; Yarno, John

    2010-01-01

    Mice are excellent subjects for use of genetic-manipulation techniques to study the basis of pathological and normal physiology and behavior; however behavioral analyses of associated phenotypes is often limited. To improve the accuracy and specificity of repeated measurements of vestibular function, we developed a miniaturized, contact-lens scleral search coil to measure mouse eye movements. We describe the physical attributes and document its functionality by measuring vestibulo-ocular responses in normal mice. This coil should greatly improve the sensitivity and documentation of vestibular dysfunction in mouse models of pathology and dysfunction while allowing screening of significant numbers of subjects. PMID:20817027

  19. The Involvement of Noradrenaline in Rapid Eye Movement Sleep Mentation

    PubMed Central

    Gottesmann, Claude

    2011-01-01

    Noradrenaline, one of the main brain monoamines, has powerful central influences on forebrain neurobiological processes which support the mental activities occurring during the sleep–waking cycle. Noradrenergic neurons are activated during waking, decrease their firing rate during slow wave sleep, and become silent during rapid eye movement (REM) sleep. Although a low level of noradrenaline is still maintained during REM sleep because of diffuse extrasynaptic release without rapid withdrawal, the decrease observed during REM sleep contributes to the mentation disturbances that occur during dreaming, which principally resemble symptoms of schizophrenia but seemingly also of attention deficit hyperactivity disorder. PMID:22180750

  20. What is the Basis for Making an Eye Movement during Reading? Technical Report No. 287.

    ERIC Educational Resources Information Center

    McConkie, George W.; And Others

    At some time during every fixation a decision is made to move the eyes, directing them to a new location in the stimulus array. To understand the eye movement control processes, three general hypotheses concerning the cognitive basis for deciding to move the eyes were investigated: the saccade (movement) initiation time is determined only on the…

  1. Perceived visual motion as effective stimulus to pursuit eye movement system

    NASA Technical Reports Server (NTRS)

    Yasui, S.; Young, L. R.

    1975-01-01

    Human eye tracking of a foveal afterimage during angular head oscillation in the dark produced smooth eye movements exceeding those for normal vestibular nystagmus, and a reduction in the frequency of the fast phase component of nystagmus eye movements. These results may support a closed loop extension of the corollary discharge theory, with oculomotor commands based on perceived object velocity.

  2. Movement Disorders and Other Motor Abnormalities in Adults With 22q11.2 Deletion Syndrome

    PubMed Central

    Boot, Erik; Butcher, Nancy J; van Amelsvoort, Thérèse AMJ; Lang, Anthony E; Marras, Connie; Pondal, Margarita; Andrade, Danielle M; Fung, Wai Lun Alan; Bassett, Anne S

    2015-01-01

    Movement abnormalities are frequently reported in children with 22q11.2 deletion syndrome (22q11.2DS), but knowledge in this area is scarce in the increasing adult population. We report on five individuals illustrative of movement disorders and other motor abnormalities in adults with 22q11.2DS. In addition to an increased susceptibility to neuropsychiatric disorders, seizures, and early-onset Parkinson disease, the underlying brain dysfunction associated with 22q11.2DS may give rise to an increased vulnerability to multiple movement abnormalities, including those influenced by medications. Movement abnormalities may also be secondary to treatable endocrine diseases and congenital musculoskeletal abnormalities. We propose that movement abnormalities may be common in adults with 22q11.2DS and discuss the implications and challenges important to clinical practice. PMID:25684639

  3. Neurological Basis for Eye Movements of the Blind

    PubMed Central

    Schneider, Rosalyn M.; Thurtell, Matthew J.; Eisele, Sylvia; Lincoff, Norah; Bala, Elisa; Leigh, R. John

    2013-01-01

    When normal subjects fix their eyes upon a stationary target, their gaze is not perfectly still, due to small movements that prevent visual fading. Visual loss is known to cause greater instability of gaze, but reported comparisons with normal subjects using reliable measurement techniques are few. We measured binocular gaze using the magnetic search coil technique during attempted fixation (monocular or binocular viewing) of 4 individuals with childhood-onset of monocular visual loss, 2 individuals with late-onset monocular visual loss due to age-related macular degeneration, 2 individuals with bilateral visual loss, and 20 healthy control subjects. We also measured saccades to visual or somatosensory cues. We tested the hypothesis that gaze instability following visual impairment is caused by loss of inputs that normally optimize the performance of the neural network (integrator), which ensures both monocular and conjugate gaze stability. During binocular viewing, patients with early-onset monocular loss of vision showed greater instability of vertical gaze in the eye with visual loss and, to a lesser extent, in the normal eye, compared with control subjects. These vertical eye drifts were much more disjunctive than upward saccades. In individuals with late monocular visual loss, gaze stability was more similar to control subjects. Bilateral visual loss caused eye drifts that were larger than following monocular visual loss or in control subjects. Accurate saccades could be made to somatosensory cues by an individual with acquired blindness, but voluntary saccades were absent in an individual with congenital blindness. We conclude that the neural gaze-stabilizing network, which contains neurons with both binocular and monocular discharge preferences, is under adaptive visual control. Whereas monocular visual loss causes disjunctive gaze instability, binocular blindness causes both disjunctive and conjugate gaze instability (drifts and nystagmus). Inputs that

  4. [The concept of tic in the history of abnormal movements].

    PubMed

    Dordain, G

    1986-01-01

    History of abnormal movements started during the 14th century. At that time the St Vitus' Dance was described, but the nosology of dyskinesias remained confusing during the next five centuries. The concept of tic was elaborated in France during the 18th century. It remained too large a concept however. Definitive semiologies appeared at the end of the 19th century, thus allowing tics to emerge from the "chaos of choreas". The etymology of the word "tic" still remains mysterious. In 1905, Meige thought that the word tic was used for the first time by reference to horses. He referred to the tic of the bear in the horse described by Rudler and Chomel at The Société de Neurologie de Paris in 1903. Veterinarians were thus probably the first to describe the word. If so, however, the horse must leave anteriority to the goat. The word Ticq was used in 1611 as mentioned by the French dictionary Robert. The word is said to be an onomatopea and is compared to the italian word ticchio which means caprice. Another dictionary (Littré) suggest the german word "ticken", which means "to touch slightly", the galic word tacaid (sudden pain) and the german ziki (young goat), a word which could have lead to ticchio as capra, goat in italian, gave capricio. PMID:3547545

  5. Perceptual bias, more than age, impacts on eye movements during face processing.

    PubMed

    Williams, Louise R; Grealy, Madeleine A; Kelly, Steve W; Henderson, Iona; Butler, Stephen H

    2016-02-01

    Consistent with the right hemispheric dominance for face processing, a left perceptual bias (LPB) is typically demonstrated by younger adults viewing faces and a left eye movement bias has also been revealed. Hemispheric asymmetry is predicted to reduce with age and older adults have demonstrated a weaker LPB, particularly when viewing time is restricted. What is currently unclear is whether age also weakens the left eye movement bias. Additionally, a right perceptual bias (RPB) for facial judgments has less frequently been demonstrated, but whether this is accompanied by a right eye movement bias has not been investigated. To address these issues older and younger adults' eye movements and gender judgments of chimeric faces were recorded in two time conditions. Age did not significantly weaken the LPB or eye movement bias; both groups looked initially to the left side of the face and made more fixations when the gender judgment was based on the left side. A positive association was found between LPB and initial saccades in the freeview condition and with all eye movements (initial saccades, number and duration of fixations) when time was restricted. The accompanying eye movement bias revealed by LPB participants contrasted with RPB participants who demonstrated no eye movement bias in either time condition. Consequently, increased age is not clearly associated with weakened perceptual and eye movement biases. Instead an eye movement bias accompanies an LPB (particularly under restricted viewing time conditions) but not an RPB. PMID:26799983

  6. Eye Movements Provide an Index of Veridical Memory for Temporal Order

    PubMed Central

    Pathman, Thanujeni; Ghetti, Simona

    2015-01-01

    The present research examined whether eye movements during retrieval capture the relation between an event and its temporal attributes. In two experiments (N=76), we found converging evidence that eye movements reflected the veridicality of memory for temporal order seconds before overt memory judgments, suggesting that these movements captured indirect access to temporal information. These eye movements did not entirely depend on the amount of contextual cueing available (Experiment 1) and reflected the unique ordinal position of an event in a sequence (Experiment 2). Based on our results, we conclude that eye movements reflected the absolute temporal order of past events. PMID:25993437

  7. Abnormal increase of intraocular pressure in fellow eye after severe ocular trauma

    PubMed Central

    Vaajanen, Anu; Tuulonen, Anja

    2016-01-01

    Abstract Background: An ocular injury can lead to secondary glaucoma in the traumatized eye in 3% to 20% of cases. Literature on the risk of developing elevated intraocular pressure in the nontraumatized fellow eye is scant. Clinicians treating ocular traumas should also bear in mind sympathetic ophthalmia, a rare bilateral granulomatous panuveitis following accidental or surgical trauma to 1 eye. Case report: We report a case of high-pressure glaucoma of the fellow eye without any signs of uveitis. The left eye of a 24-year-old man was injured in an inadvertent movement during a free-time table-tennis match. The eye was severely crushed, leading to blindness. His right eye developed medically uncontrolled high-pressure glaucoma only 1 month after the injury. Conclusion: To the best of our knowledge, there are no previous reports of post-traumatic glaucoma in the nontraumatized eye after open-globe injury. PMID:27495058

  8. Eye movements reveal epistemic curiosity in human observers.

    PubMed

    Baranes, Adrien; Oudeyer, Pierre-Yves; Gottlieb, Jacqueline

    2015-12-01

    Saccadic (rapid) eye movements are primary means by which humans and non-human primates sample visual information. However, while saccadic decisions are intensively investigated in instrumental contexts where saccades guide subsequent actions, it is largely unknown how they may be influenced by curiosity - the intrinsic desire to learn. While saccades are sensitive to visual novelty and visual surprise, no study has examined their relation to epistemic curiosity - interest in symbolic, semantic information. To investigate this question, we tracked the eye movements of human observers while they read trivia questions and, after a brief delay, were visually given the answer. We show that higher curiosity was associated with earlier anticipatory orienting of gaze toward the answer location without changes in other metrics of saccades or fixations, and that these influences were distinct from those produced by variations in confidence and surprise. Across subjects, the enhancement of anticipatory gaze was correlated with measures of trait curiosity from personality questionnaires. Finally, a machine learning algorithm could predict curiosity in a cross-subject manner, relying primarily on statistical features of the gaze position before the answer onset and independently of covariations in confidence or surprise, suggesting potential practical applications for educational technologies, recommender systems and research in cognitive sciences. With this article, we provide full access to the annotated database allowing readers to reproduce the results. Epistemic curiosity produces specific effects on oculomotor anticipation that can be used to read out curiosity states. PMID:26518743

  9. Smooth pursuit eye movements in patients with macular degeneration

    PubMed Central

    Shanidze, Natela; Fusco, Giovanni; Potapchuk, Elena; Heinen, Stephen; Verghese, Preeti

    2016-01-01

    Currently, there are no quantitative studies of smooth pursuit, a behavior attributed to the fovea, in individuals with macular degeneration (MD). We hypothesize that pursuit in MD patients depends on the relative positions of the scotoma and target trajectory. We tested this hypothesis with a scanning laser ophthalmoscope (SLO), which allows for direct visualization of the target on the damaged retina. Monocular microperimetry and eye movements were assessed in eleven individuals with differing degrees of MD. Observers were asked to visually track a 1.7° target that moved in one of eight radial directions at 5°/s–6°/s. Consistent with our hypothesis, pursuit metrics depended on whether the target moved into or out of scotoma. Pursuit gains decreased with increasing scotoma extent in the target's heading direction (p = 0.017). Latencies were higher when the scotoma was present along the target trajectory (in either starting or heading directions, p < 0.001). Furthermore, an analysis of retinal position shows that targets fell on the fixational locus nearly 50% of the time. The results suggest that MD patients are capable of smooth pursuit eye movements, but are limited by target trajectory and scotoma characteristics. PMID:26830707

  10. Top-down guided eye movements: peripheral model

    NASA Astrophysics Data System (ADS)

    Chernyak, Dimitri A.; Stark, Lawrence W.

    2001-06-01

    Eye movements are an important aspect of human visual behavior. The temporal and space-variant nature of sampling a visual scenes requires frequent attentional gaze shifts, saccades, to fixate onto different parts of an image. Fixations are often directed towards the most informative regions in the visual scene. We introduce a model and its simulation that can select such regions based on prior knowledge of similar scenes. Having representations of scene categories as probabilistic combination of hypothetical objects, i.e., prototypical regions with certain properties, it is possible to assess the likely contribution of each image region to the successive recognition process. The regions are obtained by segmenting low-resolution images using the normalized cut algorithm. Based on low-level features, such as average color, size, position, regions are clustered into a small set of hypothetical objects. Using conditions probabilities for each object given the scene category, the model can then predict the informative value of the corresponding region and initiate a sequential spatial information-gathering algorithm analogous to an eye movement saccade to a new fixation. The article demonstrates how the initial hypothesis determines the next region of interest to visit and how these scene hypotheses are affected by sequentially visiting each new image region.

  11. Compression of time during smooth pursuit eye movements.

    PubMed

    Schütz, Alexander C; Morrone, M Concetta

    2010-12-01

    Humans have a clear sense for the passage of time, but while implicit motor timing is quite accurate, explicit timing is prone to distortions particularly during action (Wenke & Haggard, 2009) and saccadic eye movements (Morrone, Ross, & Burr, 2005). Here, we investigated whether perceived duration is also affected by the execution of smooth pursuit eye movements, showing a compression of apparent duration similar to that observed during saccades. To this end, we presented two brief bars that marked intervals between 100 and 300 ms and asked subjects to judge their duration during fixation and pursuit. We found a compression of perceived duration for bars modulated in luminance contrast of about 32% and for bars modulated in chromatic contrast of 14% during pursuit compared to fixation. Interestingly, Weber ratios were similar for fixation and pursuit, if they are expressed as ratio between JND and perceived duration. This compression was constant for pursuit speeds from 7 to 14 deg/s and did not occur for intervals marked by auditory events. These results argue for a modality-specific component in the processing of temporal information. PMID:20691204

  12. Receptive fields for smooth pursuit eye movements and motion perception.

    PubMed

    Debono, Kurt; Schütz, Alexander C; Spering, Miriam; Gegenfurtner, Karl R

    2010-12-01

    Humans use smooth pursuit eye movements to track moving objects of interest. In order to track an object accurately, motion signals from the target have to be integrated and segmented from motion signals in the visual context. Most studies on pursuit eye movements used small visual targets against a featureless background, disregarding the requirements of our natural visual environment. Here, we tested the ability of the pursuit and the perceptual system to integrate motion signals across larger areas of the visual field. Stimuli were random-dot kinematograms containing a horizontal motion signal, which was perturbed by a spatially localized, peripheral motion signal. Perturbations appeared in a gaze-contingent coordinate system and had a different direction than the main motion including a vertical component. We measured pursuit and perceptual direction discrimination decisions and found that both steady-state pursuit and perception were influenced most by perturbation angles close to that of the main motion signal and only in regions close to the center of gaze. The narrow direction bandwidth (26 angular degrees full width at half height) and small spatial extent (8 degrees of visual angle standard deviation) correspond closely to tuning parameters of neurons in the middle temporal area (MT). PMID:20932990

  13. Universality in eye movements and reading: A trilingual investigation.

    PubMed

    Liversedge, Simon P; Drieghe, Denis; Li, Xin; Yan, Guoli; Bai, Xuejun; Hyönä, Jukka

    2016-02-01

    Universality in language has been a core issue in the fields of linguistics and psycholinguistics for many years (e.g., Chomsky, 1965). Recently, Frost (2012) has argued that establishing universals of process is critical to the development of meaningful, theoretically motivated, cross-linguistic models of reading. In contrast, other researchers argue that there is no such thing as universals of reading (e.g., Coltheart & Crain, 2012). Reading is a complex, visually mediated psychological process, and eye movements are the behavioural means by which we encode the visual information required for linguistic processing. To investigate universality of representation and process across languages we examined eye movement behaviour during reading of very comparable stimuli in three languages, Chinese, English and Finnish. These languages differ in numerous respects (character based vs. alphabetic, visual density, informational density, word spacing, orthographic depth, agglutination, etc.). We used linear mixed modelling techniques to identify variables that captured common variance across languages. Despite fundamental visual and linguistic differences in the orthographies, statistical models of reading behaviour were strikingly similar in a number of respects, and thus, we argue that their composition might reflect universality of representation and process in reading. PMID:26605961

  14. Large pupils predict goal-driven eye movements.

    PubMed

    Mathôt, Sebastiaan; Siebold, Alisha; Donk, Mieke; Vitu, Françoise

    2015-06-01

    Here we report that large pupils predict fixations of the eye on low-salient, inconspicuous parts of a visual scene. We interpret this as showing that mental effort, reflected by a dilation of the pupil, is required to guide gaze toward objects that are relevant to current goals, but that may not be very salient. When mental effort is low, reflected by a constriction of the pupil, the eyes tend to be captured by high-salient parts of the image, irrespective of top-down goals. The relationship between pupil size and visual saliency was not driven by luminance or a range of other factors that we considered. Crucially, the relationship was strongest when mental effort was invested exclusively in eye-movement control (i.e., reduced in a dual-task setting), which suggests that it is not due to general effort or arousal. Our finding illustrates that goal-driven control during scene viewing requires mental effort, and that pupil size can be used as an online measure to track the goal-drivenness of behavior. PMID:25867221

  15. Covert tracking: a combined ERP and fixational eye movement study.

    PubMed

    Makin, Alexis D J; Poliakoff, Ellen; Ackerley, Rochelle; El-Deredy, Wael

    2012-01-01

    Attention can be directed to particular spatial locations, or to objects that appear at anticipated points in time. While most work has focused on spatial or temporal attention in isolation, we investigated covert tracking of smoothly moving objects, which requires continuous coordination of both. We tested two propositions about the neural and cognitive basis of this operation: first that covert tracking is a right hemisphere function, and second that pre-motor components of the oculomotor system are responsible for driving covert spatial attention during tracking. We simultaneously recorded event related potentials (ERPs) and eye position while participants covertly tracked dots that moved leftward or rightward at 12 or 20°/s. ERPs were sensitive to the direction of target motion. Topographic development in the leftward motion was a mirror image of the rightward motion, suggesting that both hemispheres contribute equally to covert tracking. Small shifts in eye position were also lateralized according to the direction of target motion, implying covert activation of the oculomotor system. The data addresses two outstanding questions about the nature of visuospatial tracking. First, covert tracking is reliant upon a symmetrical frontoparietal attentional system, rather than being right lateralized. Second, this same system controls both pursuit eye movements and covert tracking. PMID:22719893

  16. 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

  17. GBA mutations are associated with Rapid Eye Movement Sleep Behavior Disorder

    PubMed Central

    Gan-Or, Ziv; Mirelman, Anat; Postuma, Ronald B; Arnulf, Isabelle; Bar-Shira, Anat; Dauvilliers, Yves; Desautels, Alex; Gagnon, Jean-François; Leblond, Claire S; Frauscher, Birgit; Alcalay, Roy N; Saunders-Pullman, Rachel; Bressman, Susan B; Marder, Karen; Monaca, Christelle; Högl, Birgit; Orr-Urtreger, Avi; Dion, Patrick A; Montplaisir, Jacques Y; Giladi, Nir; Rouleau, Guy A

    2015-01-01

    Rapid eye movement sleep behavior disorder and GBA mutations are both associated with Parkinson's disease. The GBA gene was sequenced in idiopathic rapid eye movement sleep behavior disorder patients (n = 265), and compared to controls (n = 2240). Rapid eye movement sleep behavior disorder questionnaire was performed in an independent Parkinson's disease cohort (n = 120). GBA mutations carriers had an OR of 6.24 (10.2% in patients vs. 1.8% in controls, P < 0.0001) for rapid eye movement sleep behavior disorder, and among Parkinson's disease patients, the OR for mutation carriers to have probable rapid eye movement sleep behavior disorder was 3.13 (P = 0.039). These results demonstrate that rapid eye movement sleep behavior disorder is associated with GBA mutations, and that combining genetic and prodromal data may assist in identifying individuals susceptible to Parkinson's disease. PMID:26401515

  18. Keep your eyes on the ball: smooth pursuit eye movements enhance prediction of visual motion.

    PubMed

    Spering, Miriam; Schütz, Alexander C; Braun, Doris I; Gegenfurtner, Karl R

    2011-04-01

    Success of motor behavior often depends on the ability to predict the path of moving objects. Here we asked whether tracking a visual object with smooth pursuit eye movements helps to predict its motion direction. We developed a paradigm, "eye soccer," in which observers had to either track or fixate a visual target (ball) and judge whether it would have hit or missed a stationary vertical line segment (goal). Ball and goal were presented briefly for 100-500 ms and disappeared from the screen together before the perceptual judgment was prompted. In pursuit conditions, the ball moved towards the goal; in fixation conditions, the goal moved towards the stationary ball, resulting in similar retinal stimulation during pursuit and fixation. We also tested the condition in which the goal was fixated and the ball moved. Motion direction prediction was significantly better in pursuit than in fixation trials, regardless of whether ball or goal served as fixation target. In both fixation and pursuit trials, prediction performance was better when eye movements were accurate. Performance also increased with shorter ball-goal distance and longer presentation duration. A longer trajectory did not affect performance. During pursuit, an efference copy signal might provide additional motion information, leading to the advantage in motion prediction. PMID:21289135

  19. Eye movement responses to health messages on cigarette packages

    PubMed Central

    2012-01-01

    Background While the majority of the health messages on cigarette packages contain threatening health information, previous studies indicate that risk information can trigger defensive reactions, especially when the information is self-relevant (i.e., smokers). Providing coping information, information that provides help for quitting smoking, might increase attention to health messages instead of triggering defensive reactions. Methods Eye-movement registration can detect attention preferences for different health education messages over a longer period of time during message exposure. In a randomized, experimental study with 23 smoking and 41 non-smoking student volunteers, eye-movements were recorded for sixteen self-created cigarette packages containing health texts that presented either high risk or coping information combined with a high threat or a low threat smoking-related photo. Results Results of the eye movement data showed that smokers tend to spend more time looking (i.e., more unique fixations and longer dwell time) at the coping information than at the high risk information irrespective of the content of the smoking-related photo. Non-smokers tend to spend more time looking at the high risk information than at the coping information when the information was presented in combination with a high threat smoking photo. When a low threat photo was presented, non-smokers paid more attention to the coping information than to the high risk information. Results for the smoking photos showed more attention allocation for low threat photos that were presented in combination with high risk information than for low threat photos in combination with coping information. No attention differences were found for the high threat photos. Conclusions Non-smokers demonstrated an attention preference for high risk information as opposed to coping information, but only when text information was presented in combination with a high threat photo. For smokers, however, our

  20. Efficient sensory cortical coding optimizes pursuit eye movements.

    PubMed

    Liu, Bing; Macellaio, Matthew V; Osborne, Leslie C

    2016-01-01

    In the natural world, the statistics of sensory stimuli fluctuate across a wide range. In theory, the brain could maximize information recovery if sensory neurons adaptively rescale their sensitivity to the current range of inputs. Such adaptive coding has been observed in a variety of systems, but the premise that adaptation optimizes behaviour has not been tested. Here we show that adaptation in cortical sensory neurons maximizes information about visual motion in pursuit eye movements guided by that cortical activity. We find that gain adaptation drives a rapid (<100 ms) recovery of information after shifts in motion variance, because the neurons and behaviour rescale their sensitivity to motion fluctuations. Both neurons and pursuit rapidly adopt a response gain that maximizes motion information and minimizes tracking errors. Thus, efficient sensory coding is not simply an ideal standard but a description of real sensory computation that manifests in improved behavioural performance. PMID:27611214

  1. Eye movements and hazard perception in active and passive driving

    PubMed Central

    Mackenzie, Andrew K.; Harris, Julie M.

    2015-01-01

    ABSTRACT Differences in eye movement patterns are often found when comparing passive viewing paradigms to actively engaging in everyday tasks. Arguably, investigations into visuomotor control should therefore be most useful when conducted in settings that incorporate the intrinsic link between vision and action. We present a study that compares oculomotor behaviour and hazard reaction times across a simulated driving task and a comparable, but passive, video-based hazard perception task. We found that participants scanned the road less during the active driving task and fixated closer to the front of the vehicle. Participants were also slower to detect the hazards in the driving task. Our results suggest that the interactivity of simulated driving places increased demand upon the visual and attention systems than simply viewing driving movies. We offer insights into why these differences occur and explore the possible implications of such findings within the wider context of driver training and assessment. PMID:26681913

  2. Human vertical eye movement responses to earth horizontal pitch

    NASA Technical Reports Server (NTRS)

    Wall, C. 3rd; Petropoulos, A. E.

    1993-01-01

    The vertical eye movements in humans produced in response to head-over-heels constant velocity pitch rotation about a horizontal axis resemble those from other species. At 60 degrees/s these are persistent and tend to have non-reversing slow components that are compensatory to the direction of rotation. In most, but not all subjects, the slow component velocity was well characterized by a rapid build-up followed by an exponential decay to a non-zero baseline. Super-imposed was a cyclic or modulation component whose frequency corresponded to the time for one revolution and whose maximum amplitude occurred during a specific head orientation. All response components (exponential decay, baseline and modulation) were larger during pitch backward compared to pitch forward runs. Decay time constants were shorter during the backward runs, thus, unlike left to right yaw axis rotation, pitch responses display significant asymmetries between paired forward and backward runs.

  3. Characteristics of Fixational Eye Movements in People With Macular Disease

    PubMed Central

    Kumar, Girish; Chung, Susana T. L.

    2014-01-01

    Purpose. Fixation stability is known to be poor for people with macular disease and has been suggested as a contributing factor for the poor visual performance of these individuals. In this study, we examined the characteristics of the different components of fixational eye movements and determined the component that plays a major role in limiting fixation stability in people with macular disease. Methods. Sixteen observers with macular disease and 14 older adults with normal vision (control observers) monocularly fixated a small cross presented using a Rodenstock scanning laser ophthalmoscope, for trials of 30 seconds. The retinal image and the position of the cross on the retina were recorded digitally. Eye movements were extracted from the recorded videos at a sampling rate of 540 Hz using a cross-correlation technique. A velocity criterion of 8°/s was used to differentiate between slow drifts and microsaccades. Results. Observers with macular disease demonstrated higher fixation instability, larger amplitudes of slow drifts and microsaccades, and lower drift velocities, when compared with older adults with normal vision. The velocity and the rate of microsaccades were comparable between the two groups of observers. Multiple linear regression analysis showed that the amplitude of microsaccades, and to a smaller extent, the amplitude of slow drifts, play a major role in limiting fixation stability. Conclusions. Fixation stability in people with macular disease is primarily limited by the amplitude of microsaccades, implying that rehabilitative strategies targeted at reducing the amplitude of microsaccades should improve fixation stability, and may lead to improved visual functions. PMID:25074769

  4. Visual search and eye movements in novel and familiar contexts

    NASA Astrophysics Data System (ADS)

    McDermott, Kyle; Mulligan, Jeffrey B.; Bebis, George; Webster, Michael A.

    2006-02-01

    Adapting to the visual characteristics of a specific environment may facilitate detecting novel stimuli within that environment. We monitored eye movements while subjects searched for a color target on familiar or unfamiliar color backgrounds, in order to test for these performance changes and to explore whether they reflect changes in salience from adaptation vs. changes in search strategies or perceptual learning. The target was an ellipse of variable color presented at a random location on a dense background of ellipses. In one condition, the colors of the background varied along either the LvsM or SvsLM cardinal axes. Observers adapted by viewing a rapid succession of backgrounds drawn from one color axis, and then searched for a target on a background from the same or different color axis. Searches were monitored with a Cambridge Research Systems Video Eyetracker. Targets were located more quickly on the background axis that observers were pre-exposed to, confirming that this exposure can improve search efficiency for stimuli that differ from the background. However, eye movement patterns (e.g. fixation durations and saccade magnitudes) did not clearly differ across the two backgrounds, suggesting that how the novel and familiar backgrounds were sampled remained similar. In a second condition, we compared search on a nonselective color background drawn from a circle of hues at fixed contrast. Prior exposure to this background did not facilitate search compared to an achromatic adapting field, suggesting that subjects were not simply learning the specific colors defining the background distributions. Instead, results for both conditions are consistent with a selective adaptation effect that enhances the salience of novel stimuli by partially discounting the background.

  5. Reflexive and voluntary control of smooth eye movements

    NASA Astrophysics Data System (ADS)

    Mulligan, Jeffrey B.; Stevenson, Scott B.; Cormack, Lawrence K.

    2013-03-01

    An understanding of visually evoked smooth eye movements is required to predict the visibility and legibility of moving displays, such as might be encountered in vehicles like aircraft and automobiles. We have studied the response of the oculomotor system to various classes of visual stimuli, and analyzed the results separately for horizontal and vertical version (in which the two eyes move together), and horizontal and vertical vergence (where they move in opposite directions). Of the four types of motion, only vertical vergence cannot be performed under voluntary control, and certain stimuli (all having relatively long latencies) are incapable of evoking it. In another experiment, we instructed observers to track one of two targets, and measured weak but reliable responses to the unattended target, in which the long-latency component of the response is abolished. Our results are consistent with a system containing two distinct processes, a fast reflexive process which responds to a restricted class of stimuli, and a slower voluntary process capable of following anything that can be seen, but incapable of controlling vertical vergence.

  6. Neuro-ophthalmology of eye-movement disorders.

    PubMed

    Hamilton, S R

    1999-12-01

    Magnetic resonance and functional brain imaging continue to expand their roles in complementing the clinical examination to localize the causes of eye-movement disorders. A retrospective review from county-based clinical practices emphasized generally benign causes of third, fourth, and sixth cranial nerve palsies in children, but a study from a tertiary referral center found a high incidence of neoplasms causing sixth-nerve palsies in children. A prospective study found that 38% of diabetic patients with third-nerve palsies had anisocoria up to 2.5 mm. An initial attempt to develop an evidence-based practice pathway for the evaluation of ocular motor nerve palsies has been developed for isolated sixth-nerve palsies in adults. In an important study of Graves hyperthyroidism, treatment with radioactive iodine was more likely than methimazole therapy alone to be associated with the appearance or worsening of ophthalmopathy. The clinical worsening of eye findings could be prevented by concurrent administration of corticosteroids for 3 months. Smoking is still a major controllable risk factor for thyroid ophthalmopathy. PMID:10662245

  7. Conceptual Change, Text Comprehension and Eye Movements During Reading

    NASA Astrophysics Data System (ADS)

    Penttinen, Marjaana; Anto, Erkki; Mikkilä-Erdmann, Mirjamaija

    2013-08-01

    In the two studies presented in this article, we examine the interplay of conceptual change, text comprehension, and eye-movements during reading and develop and test methods suitable for such explorations. In studies 1 and 2, university students (N = 15 and 23) read a text on photosynthesis, explained their reading processes retrospectively cued with their own gaze videos, and answered written pre- and posttests. In Study 1, a case study demonstrated connections between re-readings and high-level cognitive processing. Out of all of the participants' retrospective reports, categories were formed based on the expressions referring to either situation model or textbase construction during reading. In Study 2, conceptual change learners differed from other learner groups in terms of prolonged overall reading time and a relatively high amount of expressing textbase construction at the beginning of the retrospective reporting. The results emphasise the importance of careful construction of the textbase in conceptual change and point to the benefits of complementing the eye tracking with cued retrospective reporting when examining high-level cognitive processes during reading.

  8. Individual predictions of eye-movements with dynamic scenes

    NASA Astrophysics Data System (ADS)

    Barth, Erhardt; Drewes, Jan; Martinetz, Thomas

    2003-06-01

    We present a model that predicts saccadic eye-movements and can be tuned to a particular human observer who is viewing a dynamic sequence of images. Our work is motivated by applications that involve gaze-contingent interactive displays on which information is displayed as a function of gaze direction. The approach therefore differs from standard approaches in two ways: (1) we deal with dynamic scenes, and (2) we provide means of adapting the model to a particular observer. As an indicator for the degree of saliency we evaluate the intrinsic dimension of the image sequence within a geometric approach implemented by using the structure tensor. Out of these candidate saliency-based locations, the currently attended location is selected according to a strategy found by supervised learning. The data are obtained with an eye-tracker and subjects who view video sequences. The selection algorithm receives candidate locations of current and past frames and a limited history of locations attended in the past. We use a linear mapping that is obtained by minimizing the quadratic difference between the predicted and the actually attended location by gradient descent. Being linear, the learned mapping can be quickly adapted to the individual observer.

  9. Processing Coordinate Structures in Chinese: Evidence from Eye Movements

    PubMed Central

    Qingrong, Chen; Yan, Huang

    2012-01-01

    This article reports the results of an eye-tracking experiment that investigated the processing of coordinate structures in Chinese sentence comprehension. The study tracked the eye movements of native Chinese readers as they read sentences consisting of two independent clauses connected by the word huo zhe. The data strongly confirmed readers' preference for an initial noun phrase (NP)-coordination parsing in Chinese coordination structure. When huo zhe was absent from the beginning of a sentence, we identified a cost associated with abandoning the NP-coordination analysis, which was evident with regard to the second NP when the coordination was unambiguous. Otherwise, this cost was evident with regard to the verb, the syntactically disambiguating region, when the coordination was ambiguous. However, the presence of a sentence-initial huo zhe reduced reading times and regressions in the huo zhe NP and the verb regions. We believe that the word huo zhe at the beginning of a sentence helps the reader predict that the sentence contains a parallel structure. Before the corresponding phrases appear, the readers can use the word huo zhe and the language structure thereafter to predicatively construct the syntactic structure. Such predictive capability can eliminate the reader's preference for NP-coordination analysis. Implications for top-down parsing theory and models of initial syntactic analysis and reanalysis are discussed. PMID:22558163

  10. Restriction of pursuit eye movement range during a concurrent auditory task

    NASA Technical Reports Server (NTRS)

    Malmstrom, F. V.; Reed, L. E.; Randle, R. J.

    1983-01-01

    A two-part experiment was performed using 10 naive adult male subjects to determine the effects of a concurrent auditory dot/dash identification task on pursuit eye movements. Results indicated there was a significant (20 percent) but transitory task-induced restriction of the range of both an 18 deg horizontal and a 14 deg vertical pursuit eye movement visual angle. Furthermore, doubling the presentation rate of the concurrent task accounted for an additional 5 percent restriction of pursuit eye movement range. Results also indicated that the eye movement range is unaffected by both prior knowledge of the task and four consecutive practice trials. It is suggested that both the rapidity of target movement and the presence of concurrent mental tasks could significantly shrink an operator's pursuit eye movement ranges during viewing of dynamic visual displays such as airborne low-level television and forward-looking infrared.

  11. The character of abnormalities found in eye development of quail embruos exposed under space flight conditions

    NASA Astrophysics Data System (ADS)

    Grigoryan, E.; Dadheva, O.; Polinskaya, V.; Guryeva, T.

    The avian embryonic eye is used as a model system for studies on the environmental effects on central nervous system development. Here we present results of qualitative investigation of the eye development in quail embryos incubated in micro-"g" environment. In this study we used eyes of Japanese quail (Coturnix coturnix Japonica) embryos "flown" onboard biosatellite Kosmos-1129 and on Mir station within the framework of Mir-NASA Program. Eyes obtained from embryos ranging in age from 3-12 days (E3-E12) were prepared histologically and compared with those of the synchronous and laboratory gound controls. Ther most careful consideration was given to finding and analysis of eye developmental abnormalities. Then they were compared with those already described by experimental teratology for birds and mammals. At the stage of the "eye cup" (E3) we found the case of invalid formation of the inner retina. The latter was represented by disorganized neuroblasts occupying whole posterior chamber of the eye. On the 7th day of quail eye development, at the period of cellular growth activation some cases of small eyes with many folds of overgrowing neural and pigmented retinal layers were detected. In retinal folds of these eyes the normal layering was disturbed as well as the formation of aqueous body and pecten oculi. At this time point the changes were also found in the anterior part of the eye. The peculiarities came out of the bigger width of the cornea and separation of its layers, but were found in synchronous control as well. Few embryos of E10 had also eyes with the abnormities described for E7 but this time they were more vivid because of the completion of eye tissue differentiation. At the stage E12 we found the case evaluated as microphthalmia attending by overgrowth of anterior pigmented tissues - iris and ciliary body attached with the cornea. Most, but not all, of abnormalities we found in eye morphogeneses belonged to the birds "flown" aboard Kosmos- 1129 and

  12. Smooth Pursuit Eye Movements in Children with Strabismus and in Children with Vergence Deficits

    PubMed Central

    Lions, Cynthia; Bui-Quoc, Emmanuel; Wiener-Vacher, Sylvette; Seassau, Magali; Bucci, Maria Pia

    2013-01-01

    Purpose The objective of our study was to examine horizontal smooth pursuit performance in strabismic children and in children with vergence deficits, and to compare these data with those recorded in a group of control age-matched children. Methods Binocular eye movements were recorded by video-oculography in ten strabismic children (mean age: 9.8±0.8) and seven children with vergence deficits (mean age: 10.8±0.6). Data were compared to that of age-matched control children (mean age: 9.8±0.8 years). Results Catch-up saccades amplitude in strabismic children and in children with vergence deficits were significantly higher than in control age-matched children. Moreover, in strabismic children the amplitude of catch-up saccades was significantly higher in rightward than in leftward direction. The number of catch-up saccades was also significantly higher in rightward than in leftward direction. The gain value of pursuits in rightward direction was significantly higher in the right eye than in the left one; for the right eye, the gain value was significantly higher in rightward than in leftward direction. Binocular coordination of pursuit was better in control age-matched children than in children with vergence deficits and than in strabismic children. Conclusions Binocular coordination of pursuit is abnormal in children with vergence deficits and worse in strabismic children. Binocular vision plays an important role in improving binocular coordination of pursuit. PMID:24376777

  13. Differences in Eye Movements Control among Dyslexic, Retarded and Normal Readers in the Spanish Population.

    ERIC Educational Resources Information Center

    Martos, F. J.; Vila, J.

    1990-01-01

    Examines the relationship between dyslexia and eye movement control in Spanish-speaking children. Finds no significant differences between dyslexic and retarded readers in their eye movements during reading tasks only; no significant differences between retarded and normal readers in ocular tracking but differences between each of the groups and…

  14. The Prosodic Property of Lexical Stress Affects Eye Movements during Silent Reading

    ERIC Educational Resources Information Center

    Ashby, J.; Clifton Jr., C.

    2005-01-01

    The present study examined lexical stress in the context of silent reading by measuring eye movements. We asked whether lexical stress registers in the eye movement record and, if so, why. The study also tested the implicit prosody hypothesis, or the idea that readers construct a prosodic contour during silent reading. Participants read high and…

  15. Eye Movement Preferences As Individual Differences in Learning From Color and Non-Color Pictures.

    ERIC Educational Resources Information Center

    Caban, Juan Pedro

    An experiment compared the effectiveness of color and non-color (black-and-white) pictures in a paired associate learning task. The study also used individual eye movement quantifications as a predictor of preference for color and non-color pictures. Specifically, eye movement fixation patterns were used as indices of preference for color and…

  16. Eye Movement Techniques in Studying Differences among Developing Readers. Technical Report No. 377.

    ERIC Educational Resources Information Center

    McConkie, George W.; Zola, David

    Research involving eye movement monitoring can help in understanding the nature of the mental processes involved in reading, how these develop as one learns to read, and what processing strategies or characteristics are more common in those children who fail to show normal progress in learning to read. First, eye movement records show that the…

  17. 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…

  18. 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…

  19. 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…

  20. Effects of Bilateral Eye Movements on Gist Based False Recognition in the DRM Paradigm

    ERIC Educational Resources Information Center

    Parker, Andrew; Dagnall, Neil

    2007-01-01

    The effects of saccadic bilateral (horizontal) eye movements on gist based false recognition was investigated. Following exposure to lists of words related to a critical but non-studied word participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Subsequent testing of recognition memory revealed that those who…

  1. 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…

  2. The Relationship of Saccadic Eye Movements to Reading Disabilities. Final Report.

    ERIC Educational Resources Information Center

    Ross, Alan O.

    Saccadic (small, rapid, and apparently involuntary) eye movements of 14 children (7- to 12-years-old) with reading difficulties and of 14 normal readers were compared before and after the problem readers underwent a 7-month individual tutoring program. At pretesting the problem readers showed a rate of eye movements that was markedly lower than…

  3. 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.…

  4. 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…

  5. 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…

  6. 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…

  7. Mental Imagery as Revealed by Eye Movements and Spoken Predicates: A Test of Neurolinguistic Programming.

    ERIC Educational Resources Information Center

    Elich, Matthew; And Others

    1985-01-01

    Tested Bandler and Grinder's proposal that eye movement direction and spoken predicates are indicative of sensory modality of imagery. Subjects reported images in the three modes, but no relation between imagery and eye movements or predicates was found. Visual images were most vivid and often reported. Most subjects rated themselves as visual,…

  8. The Neural Basis of Smooth Pursuit Eye Movements in the Rhesus Monkey Brain

    ERIC Educational Resources Information Center

    Ilg, Uwe J.; Thier, Peter

    2008-01-01

    Smooth pursuit eye movements are performed in order to prevent retinal image blur of a moving object. Rhesus monkeys are able to perform smooth pursuit eye movements quite similar as humans, even if the pursuit target does not consist in a simple moving dot. Therefore, the study of the neuronal responses as well as the consequences of…

  9. Eye-Movement Control in Newborns in Darkness and in Unstructured Light.

    ERIC Educational Resources Information Center

    Haith, Marshall M.; Goodman, Gail S.

    1982-01-01

    Infrared television recordings were made of newborns' visual activity under monocular and binocular viewing conditions. Out-of-control eye movements were substantially more frequent in the presence of uniform light fields than in darkness for both groups. A distinction between exogenous and endogenous control of eye movements in newborns is…

  10. LRP predicts smooth pursuit eye movement onset during the ocular tracking of self-generated movements.

    PubMed

    Chen, Jing; Valsecchi, Matteo; Gegenfurtner, Karl R

    2016-07-01

    Several studies have indicated that human observers are very efficient at tracking self-generated hand movements with their gaze, yet it is not clear whether this is simply a by-product of the predictability of self-generated actions or if it results from a deeper coupling of the somatomotor and oculomotor systems. In a first behavioral experiment we compared pursuit performance as observers either followed their own finger or tracked a dot whose motion was externally generated but mimicked their finger motion. We found that even when the dot motion was completely predictable in terms of both onset time and kinematics, pursuit was not identical to that produced as the observers tracked their finger, as evidenced by increased rate of catch-up saccades and by the fact that in the initial phase of the movement gaze was lagging behind the dot, whereas it was ahead of the finger. In a second experiment we recorded EEG in the attempt to find a direct link between the finger motor preparation, indexed by the lateralized readiness potential (LRP) and the latency of smooth pursuit. After taking into account finger movement onset variability, we observed larger LRP amplitudes associated with earlier smooth pursuit onset across trials. The same held across subjects, where average LRP onset correlated with average eye latency. The evidence from both experiments concurs to indicate that a strong coupling exists between the motor systems leading to eye and finger movements and that simple top-down predictive signals are unlikely to support optimal coordination. PMID:27009159

  11. 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…

  12. Bilateral Saccadic Eye Movements and Tactile Stimulation, but Not Auditory Stimulation, Enhance Memory Retrieval

    ERIC Educational Resources Information Center

    Nieuwenhuis, Sander; Elzinga, Bernet M.; Ras, Priscilla H.; Berends, Floris; Duijs, Peter; Samara, Zoe; Slagter, Heleen A.

    2013-01-01

    Recent research has shown superior memory retrieval when participants make a series of horizontal saccadic eye movements between the memory encoding phase and the retrieval phase compared to participants who do not move their eyes or move their eyes vertically. It has been hypothesized that the rapidly alternating activation of the two hemispheres…

  13. Changes of vertical eye movements of goldfish for different otolith stimulation by linear acceleration

    NASA Astrophysics Data System (ADS)

    Takabayashi, A.; Ohmura-Iwasaki, T.; Mori, S.

    2003-10-01

    Eye movements serves to hold the gaze steady or to shift the gaze to an object of interest. On Earth, signals from otoliths can be interpreted either as linear motion or as tilt with respect to gravity. In microgravity, static tilt will no longer give rise to changes in otolith activity. However, linear acceleration as well as angular acceleration stimulate the otolith organ. Therefore, during adaptation to microgravity, otolith-mediated response such as eye movements alter. In this study, we analyzed the eye movements of goldfish during linear acceleration. The eye movements during rectangular linear acceleration along the different body axis were video-recorded. The vertical eye rotations were analyzed frame by frame. In normal fish, leftward lateral acceleration induced downward eye rotation in the left eye and upward eye rotation in the right eye. Acceleration from caudal to rostral evoked downward eye rotation in both eyes. When the direction of acceleration was shifted 15 degrees left, the responses in the left eye disappeared. These results suggested that otolith organs in each side were stimulated differently.

  14. Changes of vertical eye movements of goldfish for different otolith stimulation by linear acceleration

    NASA Astrophysics Data System (ADS)

    Takabayashi, A.; Ohmura, T.; Mori, S.

    Eye movements serve to hold the gaze steady or to shift the gaze to an object of interest. On Earth, signals from otoliths can be interpreted either as linear motion or as tilt with respect to gravity. In microgravity, static tilt will no longer give rise to change in otolith activity. However, linear acceleration as well as angular acceleration stimulate otolith organ. Therefore, during adaptation to microgravity, otolith-mediated response such as eye movements would alter. In this study, we analyzed the eye movements of goldfish during linear acceleration. The eye movements during rectangular linear acceleration along the different body axis were video-recorded. The vertical eye rotations were analyzed frame by frame. In normal fish, acceleration from caudal to rostral evoked downward eye rotation in both eyes. Leftward lateral acceleration induced downward eye rotation in left eye and upward eye rotation in right eye. When the direction of acceleration was shifted to left about 15 degrees, the responses in left eye was disappeared. These results suggested that otolith organs in each side were stimulated in different way.

  15. Eye-Movement Patterns Are Associated with Communicative Competence in Autistic Spectrum Disorders

    ERIC Educational Resources Information Center

    Norbury, Courtenay Frazier; Brock, Jon; Cragg, Lucy; Einav, Shiri; Griffiths, Helen; Nation, Kate

    2009-01-01

    Background: Investigations using eye-tracking have reported reduced fixations to salient social cues such as eyes when participants with autism spectrum disorders (ASD) view social scenes. However, these studies have not distinguished different cognitive phenotypes. Methods: The eye-movements of 28 teenagers with ASD and 18 typically developing…

  16. Smooth-pursuit eye movements without head movement disrupt the static body balance

    PubMed Central

    Kim, Sang-Yeob; Moon, Byeong-Yeon; Cho, Hyun Gug

    2016-01-01

    [Purpose] To investigate the changes of body balance in static posture in smooth-pursuit eye movements (SPEMs) without head movement. [Subjects and Methods] Forty subjects (24 males, 16 females) aged 23.24 ± 2.58 years participated. SPEMs were activated in three directions (horizontal, vertical, and diagonal movements); the target speed was set at three conditions (10°/s, 20°/s, and 30°/s); and the binocular visual field was limited to 50°. To compare the body balance changes, the general stability (ST) and the fall risk index (FI) were measured with TETRAX. The subjects wore a head-neck collar and stood on a balance plate for 32 s during each measurement in three directions. SPEMs were induced to each subject with nine target speeds and directions. All measured values were compared with those in stationary fixation. [Results] The ST and FI increased significantly in all SPEMs directions, with an increased target speed than that in stationary fixation. In the same condition of the target speed, the FI had the highest value relative to diagonal SPEMs. [Conclusion] SPEMs without head movement disrupt the stability of body balance in a static posture, and diagonal SPEMs may have a more negative effect in maintaining body balance than horizontal or vertical SPEMs. PMID:27190478

  17. Rapid eye movement sleep promotes cortical plasticity in the developing brain

    PubMed Central

    Dumoulin Bridi, Michelle C.; Aton, Sara J.; Seibt, Julie; Renouard, Leslie; Coleman, Tammi; Frank, Marcos G.

    2015-01-01

    Rapid eye movement sleep is maximal during early life, but its function in the developing brain is unknown. We investigated the role of rapid eye movement sleep in a canonical model of developmental plasticity in vivo (ocular dominance plasticity in the cat) induced by monocular deprivation. Preventing rapid eye movement sleep after monocular deprivation reduced ocular dominance plasticity and inhibited activation of a kinase critical for this plasticity (extracellular signal–regulated kinase). Chronic single-neuron recording in freely behaving cats further revealed that cortical activity during rapid eye movement sleep resembled activity present during monocular deprivation. This corresponded to times of maximal extracellular signal–regulated kinase activation. These findings indicate that rapid eye movement sleep promotes molecular and network adaptations that consolidate waking experience in the developing brain. PMID:26601213

  18. Cortical mechanisms of smooth eye movements revealed by dynamic covariations of neural and behavioral responses.

    PubMed

    Schoppik, David; Nagel, Katherine I; Lisberger, Stephen G

    2008-04-24

    Neural activity in the frontal eye fields controls smooth pursuit eye movements, but the relationship between single neuron responses, cortical population responses, and eye movements is not well understood. We describe an approach to dynamically link trial-to-trial fluctuations in neural responses to parallel variations in pursuit and demonstrate that individual neurons predict eye velocity fluctuations at particular moments during the course of behavior, while the population of neurons collectively tiles the entire duration of the movement. The analysis also reveals the strength of correlations in the eye movement predictions derived from pairs of simultaneously recorded neurons and suggests a simple model of cortical processing. These findings constrain the primate cortical code for movement, suggesting that either a few neurons are sufficient to drive pursuit at any given time or that many neurons operate collectively at each moment with remarkably little variation added to motor command signals downstream from the cortex. PMID:18439409

  19. Eye movements in reading and information processing: 20 years of research.

    PubMed

    Rayner, K

    1998-11-01

    Recent studies of eye movements in reading and other information processing tasks, such as music reading, typing, visual search, and scene perception, are reviewed. The major emphasis of the review is on reading as a specific example of cognitive processing. Basic topics discussed with respect to reading are (a) the characteristics of eye movements, (b) the perceptual span, (c) integration of information across saccades, (d) eye movement control, and (e) individual differences (including dyslexia). Similar topics are discussed with respect to the other tasks examined. The basic theme of the review is that eye movement data reflect moment-to-moment cognitive processes in the various tasks examined. Theoretical and practical considerations concerning the use of eye movement data are also discussed. PMID:9849112

  20. 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

  1. The Influence of Content Meaningfulness on Eye Movements across Tasks: Evidence from Scene Viewing and Reading

    PubMed Central

    Luke, Steven G.; Henderson, John M.

    2016-01-01

    The present study investigated the influence of content meaningfulness on eye-movement control in reading and scene viewing. Texts and scenes were manipulated to make them uninterpretable, and then eye-movements in reading and scene-viewing were compared to those in pseudo-reading and pseudo-scene viewing. Fixation durations and saccade amplitudes were greater for pseudo-stimuli. The effect of the removal of meaning was seen exclusively in the tail of the fixation duration distribution in both tasks, and the size of this effect was the same across tasks. These findings suggest that eye movements are controlled by a common mechanism in reading and scene viewing. They also indicate that not all eye movements are responsive to the meaningfulness of stimulus content. Implications for models of eye movement control are discussed. PMID:26973561

  2. Characteristics of eye movement and cognition during simulated landing of aircraft.

    PubMed

    Liu, Zhong-qi; Yuan, Xiu-gan; Liu, Wei; Wang, Rui

    2002-10-01

    Objective. To examine how the subject scans different parts of display panels and how the attention is distributed through the analysis of the eye movement principle and the cognition of the brain. Method. An experiment was conducted to simulate the airplane's landing course and eye movement data were recorded with eye movement measure system (EMMS). Result. There were three regions of interest (ROI) on which the subject's attention was concentrated. The subject's visual activity was active in the three ROIS and attention's shifting and distribution was between ROIS. Conclusion. Eye movement were driven by the top-down processing and the distribution of the attention. The consequence of the eye movement makes the subject maintain a continuous situation awareness. PMID:12449149

  3. Age-related effects of bilateral frontal eye fields lesions on rapid eye movements during REM sleep in rhesus monkeys.

    PubMed

    Yu, Shan; Liu, Ning; Zeng, Tao; Tian, Shaohua; Chen, Nanhui; Zhou, Yifeng; Ma, Yuanye

    2004-08-01

    Rapid eye movement (REM) is one of the most characteristic features of REM sleep, but the mechanisms underlying its regulation remain unclear. The present study aims to investigate whether the frontal eye field (FEF) is involved in the regulation of the rapid eye movements during REM sleep. To address this question, we ablated the FEF in four rhesus monkeys and observed the effects of the lesions on sleep architecture. After lesions, two adult monkeys did not show any lesion effect. However, in the other two adolescent monkeys, both the total duration and percentage of the rapid eye movements during REM sleep were decreased moderately. The result suggests that the relation between the FEF and the regulation of the rapid eye movements during REM sleep may be affected by age factor, also indicating that both the functions of the FEF and the mechanisms underlying the control of rapid eye movements during REM sleep might not be the same throughout the whole life span of an animal. PMID:15265590

  4. Insulinoma Masquerading as Rapid Eye Movement Sleep Behavior Disorder: Case Series and Literature Review.

    PubMed

    Suzuki, Keisuke; Kawasaki, Akiko; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Kanbayashi, Takashi; Sato, Masatoshi; Shimizu, Tetsuo; Hirata, Koichi

    2015-06-01

    Insulinoma is a rare endocrine tumor that can cause a wide variety of symptoms, including abnormal nocturnal behavior. We report on 3 patients with insulinoma who presented with abnormal nocturnal behavior and injury during sleep, which simulated rapid eye movement (REM) sleep behavior disorder (RBD). In case 1, the fasting glucose level was 15  mg/dL, and insulin levels were elevated (15  μU/mL). In case 3, when the patient was transferred to the hospital because of a disturbance of consciousness, hypoglycemia (29  mg/dL) was detected. In contrast, in case 2, fasting glucose sampling did not indicate hypoglycemia, but continuous glucose monitoring revealed nocturnal hypoglycemia. The time from initial symptoms to a diagnosis of insulinoma ranged from 7 months to 2 years. All 3 patients had previously received anticonvulsant drugs for suspected epilepsy, but the medications were ineffective. Polysomnography showed no evidence of REM sleep without atonia in any of the 3 patients. No patient remembered any events that occurred during sleep. When a patient manifests abnormal behavior during the night and early morning, glucose monitoring should be performed, especially during the night and early morning. Clinicians should be aware that although insulinomas are rare, they can mimic parasomnias, such as RBD. PMID:26107678

  5. Geometric adjustments to account for eye eccentricity in processing horizontal and vertical eye and head movement data

    NASA Technical Reports Server (NTRS)

    Huebner, W. P.; Paloski, W. H.; Reschke, M. F.; Bloomberg, J. J.

    1995-01-01

    Neglecting the eccentric position of the eyes in the head can lead to erroneous interpretation of ocular motor data, particularly for near targets. We discuss the geometric effects that eye eccentricity has on the processing of target-directed eye and head movement data, and we highlight two approaches to processing and interpreting such data. The first approach involves determining the true position of the target with respect to the location of the eyes in space for evaluating the efficacy of gaze, and it allows calculation of retinal error directly from measured eye, head, and target data. The second approach effectively eliminates eye eccentricity effects by adjusting measured eye movement data to yield equivalent responses relative to a specified reference location (such as the center of head rotation). This latter technique can be used to standardize measured eye movement signals, enabling waveforms collected under different experimental conditions to be directly compared, both with the measured target signals and with each other. Mathematical relationships describing these approaches are presented for horizontal and vertical rotations, for both tangential and circumferential display screens, and efforts are made to describe the sensitivity of parameter variations on the calculated results.

  6. Corticospinal Excitability in the Hand Muscles is Decreased During Eye Movement with Visual Occlusion.

    PubMed

    Chujo, Yuta; Jono, Yasutomo; Tani, Keisuke; Nomura, Yoshifumi; Hiraoka, Koichi

    2016-02-01

    Corticospinal excitability in the hand muscles decreases during smooth pursuit eye movement. The present study tested a hypothesis that the decrease in corticospinal excitability in the hand muscles at rest during eye movement is not caused by visual feedback but caused by motor commands to the eye muscles. Healthy men (M age = 28.4 yr., SD = 5.2) moved their eyes to the right with visual occlusion (dark goggles) while their arms and hands remained at rest. The motor-evoked potential in the hand muscles was suppressed by 19% in the third quarter of the eye-movement period, supporting a view that motor commands to the eye muscles are the cause of the decrease in corticospinal excitability in the hand muscles. The amount of the suppression was not significantly different among the muscles, indicating that modulation of corticospinal excitability in one muscle induced by eye movement is not dependent on whether eye movement direction and the direction of finger movement when the muscle contracts are identical. Thus, the finding failed to support a hypothetical view that motor commands to the eye muscles concomittantly produce motor commands to the hand muscles. Moreover, the amount of the suppression was not significantly different between the forearm positions, indicating that the suppression was not affected by proprioception of the forearm muscles when visual feedback is absent. PMID:27420319

  7. Abnormal Cortex-Muscle Interactions in Subjects with X-linked Kallmann's Syndrome and Mirror Movements

    ERIC Educational Resources Information Center

    Farmer, S. F.; Harrison, L. M.; Mayston, M. J.; Parekh, A.; James, L. M.; Stephens, J. A.

    2004-01-01

    X-linked Kallmann's (XKS) subjects, who display mirror movements, have abnormal corticospinal tracts which innervate motoneurons of the left and right distal muscles of the upper limb. The size of the abnormal ipsilateral projection is variable. We have used coherence and cumulant analysis between EEG and first dorsal interosseous muscle (1DI) EMG…

  8. Newness, Givenness and Discourse Updating: Evidence from Eye Movements

    PubMed Central

    Benatar, Ashley; Clifton, Charles

    2013-01-01

    Three experiments examined the effect of contextual givenness on eye movements in reading, following Schwarzschild’s (1999) analysis of givenness and focus-marking in which relations among entities as well as the entities themselves can be given. In each study, a context question was followed by an answer in which a critical word was either given, new, or contrastively (correctively) focused. Target words were read faster when the critical word provided given information than when it provided new information, and faster when it provided new information than when it corrected prior information. Repetition of target words was controlled in two ways: by mentioning a non-given target word in the context in a relation other than that in which it occurred as a target, and by using a synonym or subordinate of a given target to refer to it in the context question. Verbatim repetition was not responsible for the observed effects of givenness and contrastiveness. Besides clarifying previous inconsistent results of the effects of focus and givenness on reading speed, these results indicate that reading speed can be influenced essentially immediately by a reader’s discourse representation, and that the extent of the influence is graded, with corrections to a representation having a larger effect than simple additions PMID:24376304

  9. Morbidities in rapid eye movement sleep behavior disorder.

    PubMed

    Jennum, Poul; Mayer, Geert; Ju, Yo-El; Postuma, Ron

    2013-08-01

    Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD, RBD without any obvious comorbid major neurological disease), is strongly associated with numerous comorbid conditions. The most prominent is that with neurodegenerative disorders, especially synuclein-mediated disorders, above all Parkinson disease (PD). Idiopathic RBD is an important risk factor for the development of synucleinopathies. Comorbidity studies suggest that iRBD is associated with a number of other potential pre-motor manifestations of synucleinopathies such as, cognitive and olfactory impairment, reduced autonomic function, neuropsychiatric manifestations and sleep complaints. Furthermore, patients with PD and RBD may have worse prognosis in terms of impaired cognitive function and overall morbidity/mortality; in dementia, the presence of RBD is strongly associated with clinical hallmarks and pathological findings of dementia with Lewy bodies. These findings underline the progressive disease process, suggesting involvement of more brain regions in patients with a more advanced disease stage. RBD is also associated with narcolepsy, and it is likely that RBD associated with narcolepsy is a distinct subtype associated with different comorbidities. RBD is also associated with antidepressant medications, autoimmune conditions, and, in rare cases, brainstem lesions. PMID:23375425

  10. Morbidities in Rapid Eye Movement Sleep Behaviour Disorders

    PubMed Central

    Jennum, Poul; Mayer, Geert; Yo-El, Ju; Postuma, Ron

    2014-01-01

    Idiopathic Rapid Eye Movement (REM) Sleep Behaviour Disorder (iRBD, RBD without any obvious comorbid major neurological disease), is strongly associated with numerous comorbid conditions. The most prominent is that with neurodegenerative disorders, especially synuclein-mediated disorders, above all Parkinson Disease (PD). Idiopathic RBD is an important risk factor for the development of synucleinopathies. Comorbidity studies suggest that iRBD is associated with a number of other potential pre-motor manifestations of synucleinopathies such as, cognitive and olfactory impairment, reduced autonomic function, neuropsychiatric manifestations and sleep complaints. Furthermore, patients with PD and RBD may have worse prognosis in terms of impaired cognitive function and overall morbidity/mortality; in dementia, the presence of RBD is strongly associated with clinical hallmarks and pathological findings of dementia with Lewy bodies. These findings underline the progressive disease process, suggesting involvement of more brain regions in patients with a more advanced disease stage. RBD is also associated with narcolepsy, and it is likely that RBD associated with narcolepsy is a distinct subtype associated with different comorbidities. RBD is also associated with antidepressant medications, autoimmune conditions, and, in rare cases, brainstem lesions. PMID:23375425

  11. Eye movements while viewing narrated, captioned, and silent videos

    PubMed Central

    Ross, Nicholas M.; Kowler, Eileen

    2013-01-01

    Videos are often accompanied by narration delivered either by an audio stream or by captions, yet little is known about saccadic patterns while viewing narrated video displays. Eye movements were recorded while viewing video clips with (a) audio narration, (b) captions, (c) no narration, or (d) concurrent captions and audio. A surprisingly large proportion of time (>40%) was spent reading captions even in the presence of a redundant audio stream. Redundant audio did not affect the saccadic reading patterns but did lead to skipping of some portions of the captions and to delays of saccades made into the caption region. In the absence of captions, fixations were drawn to regions with a high density of information, such as the central region of the display, and to regions with high levels of temporal change (actions and events), regardless of the presence of narration. The strong attraction to captions, with or without redundant audio, raises the question of what determines how time is apportioned between captions and video regions so as to minimize information loss. The strategies of apportioning time may be based on several factors, including the inherent attraction of the line of sight to any available text, the moment by moment impressions of the relative importance of the information in the caption and the video, and the drive to integrate visual text accompanied by audio into a single narrative stream. PMID:23457357

  12. Transient spatiotopic integration across saccadic eye movements mediates visual stability.

    PubMed

    Cicchini, Guido M; Binda, Paola; Burr, David C; Morrone, M Concetta

    2013-02-01

    Eye movements pose major problems to the visual system, because each new saccade changes the mapping of external objects on the retina. It is known that stimuli briefly presented around the time of saccades are systematically mislocalized, whereas continuously visible objects are perceived as spatially stable even when they undergo large transsaccadic displacements. In this study we investigated the relationship between these two phenomena and measured how human subjects perceive the position of pairs of bars briefly displayed around the time of large horizontal saccades. We show that they interact strongly, with the perisaccadic bar being drawn toward the other, dramatically altering the pattern of perisaccadic mislocalization. The interaction field extends over a wide range (200 ms and 20°) and is oriented along the retinotopic trajectory of the saccade-induced motion, suggesting a mechanism that integrates pre- and postsaccadic stimuli at different retinal locations but similar external positions. We show how transient changes in spatial integration mechanisms, which are consistent with the present psychophysical results and with the properties of "remapping cells" reported in the literature, can create transient craniotopy by merging the distinct retinal images of the pre- and postsaccadic fixations to signal a single stable object. PMID:23197453

  13. Transient spatiotopic integration across saccadic eye movements mediates visual stability

    PubMed Central

    Cicchini, Guido M.; Binda, Paola; Burr, David C.

    2013-01-01

    Eye movements pose major problems to the visual system, because each new saccade changes the mapping of external objects on the retina. It is known that stimuli briefly presented around the time of saccades are systematically mislocalized, whereas continuously visible objects are perceived as spatially stable even when they undergo large transsaccadic displacements. In this study we investigated the relationship between these two phenomena and measured how human subjects perceive the position of pairs of bars briefly displayed around the time of large horizontal saccades. We show that they interact strongly, with the perisaccadic bar being drawn toward the other, dramatically altering the pattern of perisaccadic mislocalization. The interaction field extends over a wide range (200 ms and 20°) and is oriented along the retinotopic trajectory of the saccade-induced motion, suggesting a mechanism that integrates pre- and postsaccadic stimuli at different retinal locations but similar external positions. We show how transient changes in spatial integration mechanisms, which are consistent with the present psychophysical results and with the properties of “remapping cells” reported in the literature, can create transient craniotopy by merging the distinct retinal images of the pre- and postsaccadic fixations to signal a single stable object. PMID:23197453

  14. The influence of contextual diversity on eye movements in reading.

    PubMed

    Plummer, Patrick; Perea, Manuel; Rayner, Keith

    2014-01-01

    Recent research has shown contextual diversity (i.e., the number of passages in which a given word appears) to be a reliable predictor of word processing difficulty. It has also been demonstrated that word-frequency has little or no effect on word recognition speed when accounting for contextual diversity in isolated word processing tasks. An eye-movement experiment was conducted wherein the effects of word-frequency and contextual diversity were directly contrasted in a normal sentence reading scenario. Subjects read sentences with embedded target words that varied in word-frequency and contextual diversity. All 1st-pass and later reading times were significantly longer for words with lower contextual diversity compared to words with higher contextual diversity when controlling for word-frequency and other important lexical properties. Furthermore, there was no difference in reading times for higher frequency and lower frequency words when controlling for contextual diversity. The results confirm prior findings regarding contextual diversity and word-frequency effects and demonstrate that contextual diversity is a more accurate predictor of word processing speed than word-frequency within a normal reading task. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23937235

  15. The existence of a hypnotic state revealed by eye movements.

    PubMed

    Kallio, Sakari; Hyönä, Jukka; Revonsuo, Antti; Sikka, Pilleriin; Nummenmaa, Lauri

    2011-01-01

    Hypnosis has had a long and controversial history in psychology, psychiatry and neurology, but the basic nature of hypnotic phenomena still remains unclear. Different theoretical approaches disagree as to whether or not hypnosis may involve an altered mental state. So far, a hypnotic state has never been convincingly demonstrated, if the criteria for the state are that it involves some objectively measurable and replicable behavioural or physiological phenomena that cannot be faked or simulated by non-hypnotized control subjects. We present a detailed case study of a highly hypnotizable subject who reliably shows a range of changes in both automatic and volitional eye movements when given a hypnotic induction. These changes correspond well with the phenomenon referred to as the "trance stare" in the hypnosis literature. Our results show that this 'trance stare' is associated with large and objective changes in the optokinetic reflex, the pupillary reflex and programming a saccade to a single target. Control subjects could not imitate these changes voluntarily. For the majority of people, hypnotic induction brings about states resembling normal focused attention or mental imagery. Our data nevertheless highlight that in some cases hypnosis may involve a special state, which qualitatively differs from the normal state of consciousness. PMID:22039474

  16. The influence of contextual diversity on eye movements in reading

    PubMed Central

    Plummer, Patrick; Perea, Manuel; Rayner, Keith

    2014-01-01

    Recent research has shown contextual diversity (i.e., the number of passages in which a given word appears) to be a reliable predictor of word processing difficulty. It has also been demonstrated that word-frequency has little or no effect on word recognition speed when accounting for contextual diversity in isolated word processing tasks. An eye-movement experiment was conducted wherein the effects of word-frequency and contextual diversity were directly contrasted in a normal sentence reading scenario. Subjects read sentences with embedded target words which varied in word frequency and contextual diversity. All first-pass and later reading times were significantly longer for words with lower contextual diversity compared to words with higher contextual diversity when controlling for word-frequency and other important lexical properties. Furthermore, there was no difference in reading times for higher frequency and lower frequency words when controlling for contextual diversity. The results confirm prior findings regarding contextual diversity and word-frequency effects and demonstrate that contextual diversity is a more accurate predictor of word processing speed than word-frequency within a normal reading task. PMID:23937235

  17. Chiropractic Management of Infantile Torticollis With Associated Abnormal Fixation of One Eye: A Case Report

    PubMed Central

    Hobaek Siegenthaler, Mette

    2015-01-01

    Objective The purpose of this case report is to describe the chiropractic management of a child with abnormal fixation of one eye and torticollis. Clinical Features A mother presented with a concern regarding her 23-month-old son who had a history of torticollis and an abnormal fixation of the right eye. She noticed the head tilt when he was about 7 months old and abnormal alignment of the right eye when the boy was 18 months old. At 15 months when he took his first steps, his head tilt became worse. At 21 months old, a neurological and orthopedic examination at the regional university children`s hospital ruled out presence of a tumor of the cervical spine or posterior fossa. The orthopedist sent the baby for chiropractic evaluation and treatment. Chiropractic exam found decreased active and passive range of motion in the cervical spine and no evidence of mass or contracture of the sternocleidomastoid muscle. Segmental palpation showed a decreased joint play and pain reaction at level C1/C2 on the right. Intervention and Outcome The chiropractic treatment consisted of spinal manipulative therapy of the cervical spine in addition to massage and stretching of the neck muscles. Within a period of 4 weeks (3 chiropractic treatments) the torticollis was nearly resolved and the abnormal fixation of the right eye was no longer apparent. No relapse of the symptomatology was observed at a follow-up consultation at 26 months. Conclusion The patient responded favorably to chiropractic care, showing a possible mechanical spinal cause for his torticollis and for the secondarily developed abnormal fixation of the right eye. PMID:26693217

  18. Measuring eye movements during locomotion: filtering techniques for obtaining velocity signals from a video-based eye monitor

    NASA Technical Reports Server (NTRS)

    Das, V. E.; Thomas, C. W.; Zivotofsky, A. Z.; Leigh, R. J.

    1996-01-01

    Video-based eye-tracking systems are especially suited to studying eye movements during naturally occurring activities such as locomotion, but eye velocity records suffer from broad band noise that is not amenable to conventional filtering methods. We evaluated the effectiveness of combined median and moving-average filters by comparing prefiltered and postfiltered records made synchronously with a video eye-tracker and the magnetic search coil technique, which is relatively noise free. Root-mean-square noise was reduced by half, without distorting the eye velocity signal. To illustrate the practical use of this technique, we studied normal subjects and patients with deficient labyrinthine function and compared their ability to hold gaze on a visual target that moved with their heads (cancellation of the vestibulo-ocular reflex). Patients and normal subjects performed similarly during active head rotation but, during locomotion, patients held their eyes more steadily on the visual target than did subjects.

  19. Differences in Sequential Eye Movement Behavior between Taiwanese and American Viewers

    PubMed Central

    Lee, Yen-Ju; Greene, Harold H.; Tsai, Chia W.; Chou, Yu J.

    2016-01-01

    Knowledge of how information is sought in the visual world is useful for predicting and simulating human behavior. Taiwanese participants and American participants were instructed to judge the facial expression of a focal face that was flanked horizontally by other faces while their eye movements were monitored. The Taiwanese participants distributed their eye fixations more widely than American participants, started to look away from the focal face earlier than American participants, and spent a higher percentage of time looking at the flanking faces. Eye movement transition matrices also provided evidence that Taiwanese participants continually, and systematically shifted gaze between focal and flanking faces. Eye movement patterns were less systematic and less prevalent in American participants. This suggests that both cultures utilized different attention allocation strategies. The results highlight the importance of determining sequential eye movement statistics in cross-cultural research on the utilization of visual context. PMID:27242610

  20. Differences in Sequential Eye Movement Behavior between Taiwanese and American Viewers.

    PubMed

    Lee, Yen-Ju; Greene, Harold H; Tsai, Chia W; Chou, Yu J

    2016-01-01

    Knowledge of how information is sought in the visual world is useful for predicting and simulating human behavior. Taiwanese participants and American participants were instructed to judge the facial expression of a focal face that was flanked horizontally by other faces while their eye movements were monitored. The Taiwanese participants distributed their eye fixations more widely than American participants, started to look away from the focal face earlier than American participants, and spent a higher percentage of time looking at the flanking faces. Eye movement transition matrices also provided evidence that Taiwanese participants continually, and systematically shifted gaze between focal and flanking faces. Eye movement patterns were less systematic and less prevalent in American participants. This suggests that both cultures utilized different attention allocation strategies. The results highlight the importance of determining sequential eye movement statistics in cross-cultural research on the utilization of visual context. PMID:27242610

  1. Eye Gaze Metrics Reflect a Shared Motor Representation for Action Observation and Movement Imagery

    ERIC Educational Resources Information Center

    McCormick, Sheree A.; Causer, Joe; Holmes, Paul S.

    2012-01-01

    Action observation (AO) and movement imagery (MI) have been reported to share similar neural networks. This study investigated the congruency between AO and MI using the eye gaze metrics, dwell time and fixation number. A simple reach-grasp-place arm movement was observed and, in a second condition, imagined where the movement was presented from…

  2. Infant and Adult Perceptions of Possible and Impossible Body Movements: An Eye-Tracking Study

    ERIC Educational Resources Information Center

    Morita, Tomoyo; Slaughter, Virginia; Katayama, Nobuko; Kitazaki, Michiteru; Kakigi, Ryusuke; Itakura, Shoji

    2012-01-01

    This study investigated how infants perceive and interpret human body movement. We recorded the eye movements and pupil sizes of 9- and 12-month-old infants and of adults (N = 14 per group) as they observed animation clips of biomechanically possible and impossible arm movements performed by a human and by a humanoid robot. Both 12-month-old…

  3. 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. PMID:27367862

  4. The association between alterations of eye movement control and cerebral intrinsic functional connectivity in Parkinson's disease.

    PubMed

    Gorges, Martin; Müller, Hans-Peter; Lulé, Dorothée; Pinkhardt, Elmar H; Ludolph, Albert C; Kassubek, Jan

    2016-03-01

    Patients with Parkinson's disease (PD) present with eye movement disturbances that accompany the cardinal motor symptoms. Previous studies have consistently found evidence that large-scale functional networks are critically involved in eye movement control. We challenged the hypothesis that altered eye movement control in patients with PD is closely related to alterations of whole-brain functional connectivity in association with the neurodegenerative process. Saccadic and pursuit eye movements by video-oculography and 'resting-state' functional MRI (3 Tesla) were recorded from 53 subjects, i.e. 31 patients with PD and 22 matched healthy controls. Video-oculographically, a broad spectrum of eye movement impairments was demonstrated in PD patients vs. controls, including interrupted smooth pursuit, hypometric saccades, and a high distractibility in anti-saccades. Significant correlations between altered oculomotor parameters and functional connectivity measures were observed, i.e. the worse the oculomotor performance was, the more the regional functional connectivity in cortical, limbic, thalamic, cerebellar, and brainstem areas was decreased. Remarkably, decreased connectivity between major nodes of the default mode network was tightly correlated with the prevalence of saccadic intrusions as a measure for distractability. In conclusion, dysfunctional eye movement control in PD seems to be primarily associated with (cortical) executive deficits, rather than being related to the ponto-cerebellar circuits or the oculomotor brainstem nuclei. Worsened eye movement performance together with the potential pathophysiological substrate of decreased intrinsic functional connectivity in predominantly oculomotor-associated cerebral functional networks may constitute a behavioral marker in PD. PMID:25749936

  5. 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. PMID:18211163

  6. 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

    SEE BOEVE ET AL DOI101093/BRAIN/AWW030 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: 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

  7. Investigating rapid eye movement sleep without atonia in Parkinson's disease using the rapid eye movement sleep behavior disorder screening questionnaire.

    PubMed

    Bolitho, Samuel J; Naismith, Sharon L; Terpening, Zoe; Grunstein, Ron R; Melehan, Kerri; Yee, Brendon J; Coeytaux, Alessandra; Gilat, Moran; Lewis, Simon J G

    2014-05-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently observed in patients with Parkinson's disease (PD). Accurate diagnosis is essential for managing this condition. Furthermore, the emergence of idiopathic RBD in later life can represent a premotor feature, heralding the development of PD. Reliable, accurate methods for identifying RBD may offer a window for early intervention. This study sought to identify whether the RBD screening questionnaire (RBDSQ) and three questionnaires focused on dream enactment were able to correctly identify patients with REM without atonia (RWA), the neurophysiological hallmark of RBD. Forty-six patients with PD underwent neurological and sleep assessment in addition to completing the RBDSQ, the RBD single question (RBD1Q), and the Mayo Sleep Questionnaire (MSQ). The REM atonia index was derived for all participants as an objective measure of RWA. Patients identified to be RBD positive on the RBDSQ did not show increased RWA on polysomnography (80% sensitivity and 55% specificity). However, patients positive for RBD on questionnaires specific to dream enactment correctly identified higher degrees of RWA and improved the diagnostic accuracy of these questionnaires. This study suggests that the RBDSQ does not accurately identify RWA, essential for diagnosing RBD in PD. Furthermore, the results suggest that self-report measures of RBD need to focus questions on dream enactment behavior to better identify RWA and RBD. Further studies are needed to develop accurate determination and quantification of RWA in RBD to improve management of patients with PD in the future. PMID:24619826

  8. More to it than meets the eye: how eye movements can elucidate the development of episodic memory.

    PubMed

    Pathman, Thanujeni; Ghetti, Simona

    2016-07-01

    The ability to recognise past events along with the contexts in which they occurred is a hallmark of episodic memory, a critical capacity. Eye movements have been shown to track veridical memory for the associations between events and their contexts (relational binding). Such eye-movement effects emerge several seconds before, or in the absence of, explicit response, and are linked to the integrity and function of the hippocampus. Drawing from research from infancy through late childhood, and by comparing to investigations from typical adults, patient populations, and animal models, it seems increasingly clear that eye movements reflect item-item, item-temporal, and item-spatial associations in developmental populations. We analyse this line of work, identify missing pieces in the literature and outline future avenues of research, in order to help elucidate the development of episodic memory. PMID:26999263

  9. 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…

  10. Eye Movements in Autistic, Mentally Retarded and Normal Young Children: Simultaneous Measurement by an Eye Camera System for Autistic Children (ECSA) and an Electro-Oculography (EOG).

    ERIC Educational Resources Information Center

    Itoh, Hideo

    1987-01-01

    Smooth pursuit eye movements and saccadic eye movements in Japanese autistic, mentally retarded, and normal young children were simultaneously measured by an eye camera system (ECS) and an electro-oculography (EOG) system. The ECS was developed in the laboratory of the Research Institute for the Education of Exceptional Children at Tokyo Gakugei…

  11. The effects of crowding on eye movement patterns in reading.

    PubMed

    Bricolo, Emanuela; Salvi, Carola; Martelli, Marialuisa; Arduino, Lisa S; Daini, Roberta

    2015-09-01

    Crowding is a phenomenon that characterizes normal periphery limiting letter identification when other letters surround the signal. We investigated the nature of the reading limitation of crowding by analyzing eye-movement patterns. The stimuli consisted of two items varying across trials for letter spacing (spaced, unspaced and increased size), lexicality (words or pseudowords), number of letters (4, 6, 8), and reading modality (oral and silent). In Experiments 1 and 2 (oral and silent reading, respectively) the results show that an increase in letter spacing induced an increase in the number of fixations and in gaze duration, but a reduction in the first fixation duration. More importantly, increasing letter size (Experiment 3) produced the same first fixation duration advantage as empty spacing, indicating that, as predicted by crowding, only center-to-center letter distance, and not spacing per se, matters. Moreover, when the letter size was enlarged the number of fixations did not increase as much as in the previous experiments, suggesting that this measure depends on visual acuity rather than on crowding. Finally, gaze duration, a measure of word recognition, did not change with the letter size enlargement. No qualitative differences were found between oral and silent reading experiments (1 and 2), indicating that the articulatory process did not influence the outcome. Finally, a facilitatory effect of lexicality was found in all conditions, indicating an interaction between perceptual and lexical processing. Overall, our results indicate that crowding influences normal word reading by means of an increase in first fixation duration, a measure of word encoding, which we interpret as a modulatory effect of attention on critical spacing. PMID:26143298

  12. Search asymmetry and eye movements in infants and adults.

    PubMed

    Adler, Scott A; Gallego, Pamela

    2014-08-01

    Search asymmetry is characterized by the detection of a feature-present target amidst feature-absent distractors being efficient and unaffected by the number of distractors, whereas detection of a feature-absent target amidst feature-present distractors is typically inefficient and affected by the number of distractors. Although studies have attempted to investigate this phenomenon with infants (e.g., Adler, Inslicht, Rovee-Collier, & Gerhardstein in Infant Behavioral Development, 21, 253-272, 1998; Colombo, Mitchell, Coldren, & Atwater in Journal of Experimental Psychology: Learning, Memory and Cognition, 19, 98-109, 1990), due to methodological limitations, their findings have been unable to definitively establish the development of visual search mechanisms in infants. The present study assessed eye movements as a means to examine an asymmetry in responding to feature-present versus feature-absent targets in 3-month-olds, relative to adults. Saccade latencies to localize a target (or a distractor, as in the homogeneous conditions) were measured as infants and adults randomly viewed feature-present (R among Ps), feature-absent (P among Rs), and homogeneous (either all Rs or all Ps) arrays at set sizes of 1, 3, 5, and 8. Results indicated that neither infants' nor adults' saccade latencies to localize the target in the feature-present arrays were affected by increasing set sizes, suggesting that localization of the target was efficient. In contrast, saccade latencies to localize the target in the feature-absent arrays increased with increasing set sizes for both infants and adults, suggesting an inefficient localization. These findings indicate that infants exhibit an asymmetry consistent with that found with adults, providing support for functional bottom-up selective attention mechanisms in early infancy. PMID:24858309

  13. Eye movements in chameleons are not truly independent - evidence from simultaneous monocular tracking of two targets.

    PubMed

    Katz, Hadas Ketter; Lustig, Avichai; Lev-Ari, Tidhar; Nov, Yuval; Rivlin, Ehud; Katzir, Gadi

    2015-07-01

    Chameleons perform large-amplitude eye movements that are frequently referred to as independent, or disconjugate. When prey (an insect) is detected, the chameleon's eyes converge to view it binocularly and 'lock' in their sockets so that subsequent visual tracking is by head movements. However, the extent of the eyes' independence is unclear. For example, can a chameleon visually track two small targets simultaneously and monocularly, i.e. one with each eye? This is of special interest because eye movements in ectotherms and birds are frequently independent, with optic nerves that are fully decussated and intertectal connections that are not as developed as in mammals. Here, we demonstrate that chameleons presented with two small targets moving in opposite directions can perform simultaneous, smooth, monocular, visual tracking. To our knowledge, this is the first demonstration of such a capacity. The fine patterns of the eye movements in monocular tracking were composed of alternating, longer, 'smooth' phases and abrupt 'step' events, similar to smooth pursuits and saccades. Monocular tracking differed significantly from binocular tracking with respect to both 'smooth' phases and 'step' events. We suggest that in chameleons, eye movements are not simply 'independent'. Rather, at the gross level, eye movements are (i) disconjugate during scanning, (ii) conjugate during binocular tracking and (iii) disconjugate, but coordinated, during monocular tracking. At the fine level, eye movements are disconjugate in all cases. These results support the view that in vertebrates, basic monocular control is under a higher level of regulation that dictates the eyes' level of coordination according to context. PMID:26157161

  14. Eye Movements and Abducens Motoneuron Behavior During Cholinergically Induced REM Sleep

    PubMed Central

    Marquez-Ruiz, Javier; Escudero, Miguel

    2009-01-01

    Study objectives: The injection of cholinergic drugs in the pons has been largely used to induce REM sleep as a useful model to study different processes during this period. In the present study, microinjections of carbachol in the nucleus reticularis pontis oralis (NRPO) were performed to test the hypothesis that eye movements and the behavior of extraocular motoneurons during induced REM sleep do not differ from those during spontaneous REM sleep. Methods: Six female adult cats were prepared for chronic recording of eye movements (by means of the search-coil technique) and electroencephalography, electromyography, ponto-geniculo-occipital (PGO) waves at the lateral geniculate nucleus, and identified abducens motoneuron activities after microinjections of the cholinergic agonist carbachol into the NRPO. Results: Unilateral microinjections (n = 13) of carbachol in the NRPO induced REM sleep-like periods in which the eyes performed a convergence and downward rotation interrupted by phasic complex rapid eye movements associated to PGO waves. During induced-REM sleep abducens motoneurons lost their tonic activity and eye position codification, but continued codifying eye velocity during the burst of eye movements. Conclusion: The present results show that eye movements and the underlying behavior of abducens motoneurons are very similar to those present during natural REM sleep. Thus, microinjection of carbachol seems to activate the structures responsible for the exclusive oculomotor behavior observed during REM sleep, validating this pharmacological model and enabling a more efficient exploration of phasic and tonic phenomena underlying eye movements during REM sleep. Citation: Marquez-Ruiz J; Escudero M. Eye movements and abducens motoneuron behavior during cholinergically induced REM sleep. SLEEP 2009;32(4):471–481. PMID:19413141

  15. An accurate and portable eye movement detector for studying sleep in small animals.

    PubMed

    Sánchez-López, Álvaro; Escudero, Miguel

    2015-08-01

    Although eye movements are a highly valuable variable in attempts to precisely identify different periods of the sleep-wake cycle, their indirect measurement by electrooculography is not good enough. The present article describes an accurate and portable scleral search coil that allows the detection of tonic and phasic characteristics of eye movements in free-moving animals. Six adult Wistar rats were prepared for chronic recording of electroencephalography, electromyography and eye movements using the scleral search coil technique. We developed a miniature magnetic field generator made with two coils, consisting of 35 turns and 15 mm diameter of insulated 0.2 mm cooper wire, mounted in a frame of carbon fibre. This portable scleral search coil was fixed on the head of the animal, with each magnetic coil parallel to the eye coil and at 5 mm from each eye. Eye movements detected by the portable scleral search coil were compared with those measured by a commercial scleral search coil requiring immobilizing the head of the animal. No qualitative differences were found between the two scleral search coil systems in their capabilities to detect eye movements. This innovative portable scleral search coil system is an essential tool to detect slow changes in eye position and miniature rapid eye movements during sleep. The portable scleral search coil is much more suitable for detecting eye movements than any previously available system because of its precision and simplicity, and because it does not require immobilization of the animal's head. PMID:25590417

  16. Dynamic Assessment of Binocular Eye Movement Coordination: Norms and Functional Implications

    PubMed Central

    Viirre, Erik

    2014-01-01

    Alignment of the two eyes is controlled by a finely tuned, fast acting system with components within the brain. Assessment of binocular alignment has classically been done statically. Eye positions are assessed in primary position and at eccentric angles to interpret the functional status of the oculomotor nerves and muscles. However, assessment of dynamic eye alignment, the coordination of the eyes during eye movements, has been less commonly carried out and has not been formalized with population norms. Clinicians are aware of slow eye movement dynamic alignment changes, such as that clinically observed in Intranuclear Ophthalmoplegia. But assessment of eye alignment during rapid eye movements, such as saccade or pursuit has not been part of neuro-ophthalmologic assessment. With the advent of inexpensive, high resolution recording systems, both eyes can be simultaneously recorded and their coordination during movement compared. Thus, we now have an opportunity to provide a laboratory based objective measurement of a gamut of binocular coordination systems. Recent research in humans has demonstrated increased variability of binocular coordination during divided attention. Variability is an interesting statistic that can be sensitively assessed in the velocity domain without extensive gaze position recalibration procedures during recording over long intervals. Variability can thus be used as a robust, long-term eye movement parameter with minimal intrusiveness to the subject. It is proposed that population studies of binocular coordination during eye movements be carried out to determine neurologic norms so that conditions such as brain injury and others can be assessed with a functional tool with objective parameters. PMID:24804278

  17. Rapid Eye Movement and Non-Rapid Eye Movement Sleep Contributions in Memory Consolidation and Resistance to Retroactive Interference for Verbal Material

    PubMed Central

    Deliens, Gaétane; Leproult, Rachel; Neu, Daniel; Peigneux, Philippe

    2013-01-01

    Study Objectives: To test the hypothesis that rapid eye movement (REM) sleep contributes to the consolidation of new memories, whereas non-rapid eye movement (NREM) sleep contributes to the prevention of retroactive interference. Design: Randomized, crossover study. Setting: Two sessions of either a morning nap or wakefulness. Participants: Twenty-five healthy young adults. Interventions: Declarative learning of word pairs followed by a nap or a wake interval, then learning of interfering word pairs and delayed recall of list A. Measurements and Results: After a restricted night (24:00-06:00), participants learned a list of word pairs (list A). They were then required to either take a nap or stay awake during 45 min, after which they learned a second list of word pairs (list B) and then had to recall list A. Fifty percent of word pairs in list B shared the first word with list A, resulting in interference. Ten subjects exhibited REM sleep whereas 13 subjects exhibited NREM stage 3 (N3) sleep. An interference effect was observed in the nap but not in the wake condition. In post-learning naps, N3 sleep was associated with a reduced interference effect, which was not the case for REM sleep. Moreover, participants exhibiting N3 sleep in the post-learning nap condition also showed a reduced interference effect in the wake condition, suggesting a higher protection ability against interference. Conclusion: Our results partly support the hypothesis that non-rapid eye movement sleep contributes in protecting novel memories against interference. However, rapid eye movement sleep-related consolidation is not evidenced. Citation: Deliens G; Leproult R; Neu D; Peigneux P. Rapid eye movement and non-rapid eye movement sleep contributions in memory consolidation and resistance to retroactive interference for verbal material. SLEEP 2013;36(12):1875-1883. PMID:24293762

  18. Effect of passive eye movement on retinogeniculate transmission in the cat.

    PubMed

    Lal, R; Friedlander, M J

    1990-03-01

    1. The nature and time window of interaction between passive phasic eye movement signals and visual stimuli were studied for dorsal lateral geniculate nucleus (LGNd) neurons in the cat. Extracellular recordings were made from single neurons in layer A of the left LGNd of anesthetized paralyzed cats in response to a normalized visual stimulus presented to the right eye at each of several times of movement of the left eye. The left eye was moved passively at a fixed amplitude and velocity while varying the movement onset time with respect to the visual stimulus onset in a randomized and interleaved fashion. Visual stimuli consisted of square-wave modulated circular spots of appropriate contrast, sign, and size to elicit an optimal excitatory response when placed in the neurons' receptive-field (RF) center. 2. Interactions were analyzed for 78 neurons (33 X-neurons, 43 Y-neurons, and 2 physiologically unclassified neurons) on 25-65 trials of identical visual stimuli for each of eight times of eye movement. 3. Sixty percent (47/78) of the neurons tested had a significant eye movement effect (ANOVA, P less than 0.05) on some aspect of their visual response. Of these 47 neurons, 42 (89%) had a significant (P less than 0.05) effect of an appropriately timed eye movement on the number of action potentials, 36 (77%) had a significant effect on the mean peak firing rate, and 31 (66%) were significantly affected as evaluated by both criteria. 4. The eye movement effect on the neurons' visual responses was primarily facilitatory. Facilitation was observed for 37 (79%) of the affected neurons. For 25 of these 37 neurons (68%), the facilitation was significant (P less than 0.05) as evaluated by both criteria (number of action potentials and mean peak firing rate). Ten (21%) of the affected neurons had their visual response significantly inhibited (P less than 0.05). 5. Sixty percent (46/78) of the neurons were tested for the effect of eye movement on both visually elicited

  19. Neurophysiological basis of rapid eye movement sleep behavior disorder: informing future drug development.

    PubMed

    Jennum, Poul; Christensen, Julie Ae; Zoetmulder, Marielle

    2016-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by a history of recurrent nocturnal dream enactment behavior and loss of skeletal muscle atonia and increased phasic muscle activity during REM sleep: REM sleep without atonia. RBD and associated comorbidities have recently been identified as one of the most specific and potentially sensitive risk factors for later development of any of the alpha-synucleinopathies: Parkinson's disease, dementia with Lewy bodies, and other atypical parkinsonian syndromes. Several other sleep-related abnormalities have recently been identified in patients with RBD/Parkinson's disease who experience abnormalities in sleep electroencephalographic frequencies, sleep-wake transitions, wake and sleep stability, occurrence and morphology of sleep spindles, and electrooculography measures. These findings suggest a gradual involvement of the brainstem and other structures, which is in line with the gradual involvement known in these disorders. We propose that these findings may help identify biomarkers of individuals at high risk of subsequent conversion to parkinsonism. PMID:27186147

  20. Neurophysiological basis of rapid eye movement sleep behavior disorder: informing future drug development

    PubMed Central

    Jennum, Poul; Christensen, Julie AE; Zoetmulder, Marielle

    2016-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by a history of recurrent nocturnal dream enactment behavior and loss of skeletal muscle atonia and increased phasic muscle activity during REM sleep: REM sleep without atonia. RBD and associated comorbidities have recently been identified as one of the most specific and potentially sensitive risk factors for later development of any of the alpha-synucleinopathies: Parkinson’s disease, dementia with Lewy bodies, and other atypical parkinsonian syndromes. Several other sleep-related abnormalities have recently been identified in patients with RBD/Parkinson’s disease who experience abnormalities in sleep electroencephalographic frequencies, sleep–wake transitions, wake and sleep stability, occurrence and morphology of sleep spindles, and electrooculography measures. These findings suggest a gradual involvement of the brainstem and other structures, which is in line with the gradual involvement known in these disorders. We propose that these findings may help identify biomarkers of individuals at high risk of subsequent conversion to parkinsonism. PMID:27186147

  1. A relationship between eye movement patterns and performance in a precognitive tracking task

    NASA Technical Reports Server (NTRS)

    Repperger, D. W.; Hartzell, E. J.

    1977-01-01

    Eye movements made by various subjects in the performance of a precognitive tracking task are studied. The tracking task persented by an antiaircraft artillery (AAA) simulator has an input forcing function represented by a deterministic aircraft fly-by. The performance of subjects is ranked by two metrics. Good, mediocre, and poor trackers are selected for analysis based on performance during the difficult segment of the tracking task and over replications. Using phase planes to characterize both the eye movement patterns and the displayed error signal, a simple metric is developed to study these patterns. Two characterizations of eye movement strategies are defined and quantified. Using these two types of eye strategies, two conclusions are obtained about good, mediocre, and poor trackers. First, the eye tracker who used a fixed strategy will consistently perform better. Secondly, the best fixed strategy is defined as a Crosshair Fixator.

  2. Rapid eye movement sleep behaviour disorder symptomatic of a brain stem cavernoma.

    PubMed

    Felix, Sandra; Thobois, Stephane; Peter-Derex, Laure

    2016-04-01

    A 75-year-old man complained of excessive daytime sleepiness (EDS), difficulty falling asleep and nocturnal agitation during sleep. Restless legs syndrome (RLS) was diagnosed and treated. Because of persistent EDS, snoring and nycturia, a nocturnal polysomnography (PSG) was performed. PSG showed high sleep fragmentation related to a moderate to severe obstructive sleep apnea syndrome. Continuous positive airway pressure treatment (CPAP) was proposed. Because of the persistence of abnormal nocturnal behaviours, characterized by screaming, punching and falling out of bed, a video-PSG with CPAP treatment was performed. The recording showed typical chin electromyography (EMG) activity increase associated with violent movements during rapid eye movement (REM) sleep, suggesting REM sleep behaviour disorders (RBD). Clinical neurological examination found no parkinsonian syndrome, no dysautonomic sign and no neurological focal sign. Dopamine transporter imaging [123I-FP-CIT single photon emission computed tomography (SPECT)] did not find any presynaptic dopaminergic pathways degeneration. Brain magnetic resonance imaging showed a vascular lesion suggestive of cavernoma located in the pons. The present case illustrates the complexity of sleep disturbance diagnosis with a possible entanglement of aetiologies responsible for nocturnal agitation, and confirms that an isolated pons cavernoma should be considered among the rare causes of RBD. PMID:26780965

  3. Eye Movements, Prosody, and Word Frequency among Average- and High-Skilled Second-Grade Readers

    ERIC Educational Resources Information Center

    Valle, Araceli; Binder, Katherine S.; Walsh, Caitlin B.; Nemier, Carolyn; Bangs, Katheryn E.

    2013-01-01

    readers (as identified by their Woodcock-Johnson III Test of Academic Achievement Broad Reading scores) differed on behavioral measures of reading related to comprehension: eye movements during silent reading and prosody during oral reading. Results from silent reading implicate…

  4. Adaptive changes of the eye movements for otolith stimulation in goldfish

    NASA Astrophysics Data System (ADS)

    Takabayashi, A.; Iwata, K.; Mori, S.

    2006-01-01

    Vestibular compensation was studied in the eye movements of goldfish. Vertical eye movements evoked by linear acceleration were analyzed for one month after unilateral removal of the otolith. No spontaneous nystagmus was observed in the goldfish following recovery from hemilabyrinthectomy surgery (a period of 30 min). However, unilateral removal of the otolith resulted in a decrease in response amplitude to linear acceleration. After one week, eye movement amplitude had increased to approximately 50% of normal. After one month of compensation, the response amplitude of eye movement was nearly normal. The results suggest that the goldfish is capable of almost completely recovering amplitude of response to linear acceleration following one month of compensation for unilateral removal of the otolith.

  5. Phonemic Awareness Contributes to Text Reading Fluency: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Ashby, Jane; Dix, Heather; Bontrager, Morgan; Dey, Rajarshi; Archer, Ana

    2013-01-01

    awareness and text reading fluency. This longitudinal study is the first to investigate this relationship by measuring eye movements during picture matching tasks and during silent sentence reading. Time spent…

  6. Adaptive changes of the eye movements for otolith stimulation in goldfish

    NASA Astrophysics Data System (ADS)

    Takabayashi, A.; Iwata, K.; Mori, S.

    Vestibular compensation was studied in the eye movements of goldfish. Torsional and vertical eye movements evoked by linear acceleration or body tilt were analyzed for ˜ 2 months after unilateral removal of the otolith. Spontaneous nystagmus was not observed in the goldfish following recovery from the surgery for hemi labyrinthectomy (a period of 30 minutes). However, unilateral removal of the otolith resulted in an acute decrease in response amplitude to linear acceleration and body tilt. After 1 week, amplitude of eye movement had increased toward normal to approximately 50% of normal. After 1 month of compensation, response amplitude of eye movement had recovered almost its normal value. The results suggest that the goldfish is capable of almost completely recovering amplitude of response to linear acceleration following 1 month of compensation for unilateral removal of otolith.

  7. Preclinical assessment of CNS drug action using eye movements in mice

    PubMed Central

    Cahill, Hugh; Rattner, Amir; Nathans, Jeremy

    2011-01-01

    The drug development process for CNS indications is hampered by a paucity of preclinical tests that accurately predict drug efficacy in humans. Here, we show that a wide variety of CNS-active drugs induce characteristic alterations in visual stimulus–induced and/or spontaneous eye movements in mice. Active compounds included sedatives and antipsychotic, antidepressant, and antiseizure drugs as well as drugs of abuse, such as cocaine, morphine, and phencyclidine. The use of quantitative eye-movement analysis was demonstrated by comparing it with the commonly used rotarod test of motor coordination and by using eye movements to monitor pharmacokinetics, blood-brain barrier penetration, drug-receptor interactions, heavy metal toxicity, pharmacologic treatment in a model of schizophrenia, and degenerative CNS disease. We conclude that eye-movement analysis could complement existing animal tests to improve preclinical drug development. PMID:21821912

  8. Noise-enhanced target discrimination under the influence of fixational eye movements and external noise

    NASA Astrophysics Data System (ADS)

    Starzynski, Christian; Engbert, Ralf

    2009-03-01

    Active motor processes are present in many sensory systems to enhance perception. In the human visual system, miniature eye movements are produced involuntarily and unconsciously when we fixate a stationary target. These fixational eye movements represent self-generated noise which serves important perceptual functions. Here we investigate fixational eye movements under the influence of external noise. In a two-choice discrimination task, the target stimulus performed a random walk with varying noise intensity. We observe noise-enhanced discrimination of the target stimulus characterized by a U-shaped curve of manual response times as a function of the diffusion constant of the stimulus. Based on the experiments, we develop a stochastic information-accumulator model for stimulus discrimination in a noisy environment. Our results provide a new explanation for the constructive role of fixational eye movements in visual perception.

  9. Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study.

    PubMed

    Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

    2015-01-01

    Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the

  10. Processing Rhythmic Pattern during Chinese Sentence Reading: An Eye Movement Study

    PubMed Central

    Luo, Yingyi; Duan, Yunyan; Zhou, Xiaolin

    2015-01-01

    Prosodic constraints play a fundamental role during both spoken sentence comprehension and silent reading. In Chinese, the rhythmic pattern of the verb-object (V-O) combination has been found to rapidly affect the semantic access/integration process during sentence reading (Luo and Zhou, 2010). Rhythmic pattern refers to the combination of words with different syllabic lengths, with certain combinations disallowed (e.g., [2 + 1]; numbers standing for the number of syllables of the verb and the noun respectively) and certain combinations preferred (e.g., [1 + 1] or [2 + 2]). This constraint extends to the situation in which the combination is used to modify other words. A V-O phrase could modify a noun by simply preceding it, forming a V-O-N compound; when the verb is disyllabic, however, the word order has to be O-V-N and the object is preferred to be disyllabic. In this study, we investigated how the reader processes the rhythmic pattern and word order information by recording the reader's eye-movements. We created four types of sentences by crossing rhythmic pattern and word order in compounding. The compound, embedding a disyllabic verb, could be in the correct O-V-N or the incorrect V-O-N order; the object could be disyllabic or monosyllabic. We found that the reader spent more time and made more regressions on and after the compounds when either type of anomaly was detected during the first pass reading. However, during re-reading (after all the words in the sentence have been viewed), less regressive eye movements were found for the anomalous rhythmic pattern, relative to the correct pattern; moreover, only the abnormal rhythmic pattern, not the violated word order, influenced the regressive eye movements. These results suggest that while the processing of rhythmic pattern and word order information occurs rapidly during the initial reading of the sentence, the process of recovering from the rhythmic pattern anomaly may ease the reanalysis processing at the

  11. 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.

  12. Effects of Individual Differences in Verbal Skills on Eye-Movement Patterns during Sentence Reading

    ERIC Educational Resources Information Center

    Kuperman, Victor; Van Dyke, Julie A.

    2011-01-01

    This study is a large-scale exploration of the influence that individual reading skills exert on eye-movement behavior in sentence reading. Seventy-one non-college-bound 16-24 year-old speakers of English completed a battery of 18 verbal and cognitive skill assessments, and read a series of sentences as their eye-movements were monitored.…

  13. The Association Between Eye Movements and Cerebellar Activation in a Verbal Working Memory Task.

    PubMed

    Peterburs, Jutta; Cheng, Dominic T; Desmond, John E

    2016-09-01

    It has been argued that cerebellar activations during cognitive tasks may masquerade as cognition, while actually reflecting processes related to movement planning or motor learning. The present study investigated whether the cerebellar load effect for verbal working memory, that is, increased activations in lobule VI/Crus I and lobule VIIB/VIIIA, is related to eye movements and oculomotor processing. Fifteen participants performed an fMRI-based Sternberg verbal working memory task. Oculomotor and cognitive task demands were manipulated by using closely and widely spaced stimuli, and high and low cognitive load. Trial-based quantitative eye movement parameters were obtained from concurrent eye tracking. Conventional MRI analysis replicated the cerebellar load effect in lobules VI and VIIB/VIIIa. With quantitative eye movement parameters as regressors, analysis yielded very similar activation patterns. While load effect and eye regressor generally recruited spatially distinct neocortical and cerebellar regions, conjunction analysis showed that a small subset of prefrontal areas implicated in the load effect also responded to the eye regressor. The present results indicate that cognitive load-dependent activations in lateral superior and posteroinferior cerebellar regions in the Sternberg task are independent of eye movements occurring during stimulus encoding. This is inconsistent with the notion that cognitive load-dependent cerebellar activations merely reflect oculomotor processing. PMID:26286918

  14. Tuning Properties of MT and MSTd and Divisive Interactions for Eye-Movement Compensation.

    PubMed

    Cao, Bo; Mingolla, Ennio; Yazdanbakhsh, Arash

    2015-01-01

    The primate brain intelligently processes visual information from the world as the eyes move constantly. The brain must take into account visual motion induced by eye movements, so that visual information about the outside world can be recovered. Certain neurons in the dorsal part of monkey medial superior temporal area (MSTd) play an important role in integrating information about eye movements and visual motion. When a monkey tracks a moving target with its eyes, these neurons respond to visual motion as well as to smooth pursuit eye movements. Furthermore, the responses of some MSTd neurons to the motion of objects in the world are very similar during pursuit and during fixation, even though the visual information on the retina is altered by the pursuit eye movement. We call these neurons compensatory pursuit neurons. In this study we develop a computational model of MSTd compensatory pursuit neurons based on physiological data from single unit studies. Our model MSTd neurons can simulate the velocity tuning of monkey MSTd neurons. The model MSTd neurons also show the pursuit compensation property. We find that pursuit compensation can be achieved by divisive interaction between signals coding eye movements and signals coding visual motion. The model generates two implications that can be tested in future experiments: (1) compensatory pursuit neurons in MSTd should have the same direction preference for pursuit and retinal visual motion; (2) there should be non-compensatory pursuit neurons that show opposite preferred directions of pursuit and retinal visual motion. PMID:26575648

  15. Tuning Properties of MT and MSTd and Divisive Interactions for Eye-Movement Compensation

    PubMed Central

    Cao, Bo; Mingolla, Ennio; Yazdanbakhsh, Arash

    2015-01-01

    The primate brain intelligently processes visual information from the world as the eyes move constantly. The brain must take into account visual motion induced by eye movements, so that visual information about the outside world can be recovered. Certain neurons in the dorsal part of monkey medial superior temporal area (MSTd) play an important role in integrating information about eye movements and visual motion. When a monkey tracks a moving target with its eyes, these neurons respond to visual motion as well as to smooth pursuit eye movements. Furthermore, the responses of some MSTd neurons to the motion of objects in the world are very similar during pursuit and during fixation, even though the visual information on the retina is altered by the pursuit eye movement. We call these neurons compensatory pursuit neurons. In this study we develop a computational model of MSTd compensatory pursuit neurons based on physiological data from single unit studies. Our model MSTd neurons can simulate the velocity tuning of monkey MSTd neurons. The model MSTd neurons also show the pursuit compensation property. We find that pursuit compensation can be achieved by divisive interaction between signals coding eye movements and signals coding visual motion. The model generates two implications that can be tested in future experiments: (1) compensatory pursuit neurons in MSTd should have the same direction preference for pursuit and retinal visual motion; (2) there should be non-compensatory pursuit neurons that show opposite preferred directions of pursuit and retinal visual motion. PMID:26575648

  16. An Examination of Cognitive Processing of Multimedia Information Based on Viewers' Eye Movements

    ERIC Educational Resources Information Center

    Liu, Han-Chin; Chuang, Hsueh-Hua

    2011-01-01

    This study utilized qualitative and quantitative designs and eye-tracking technology to understand how viewers process multimedia information. Eye movement data were collected from eight college students (non-science majors) while they were viewing web pages containing different types of text and illustrations depicting the mechanism of…

  17. Eye Movements Reveal the Influence of Event Structure on Reading Behavior

    ERIC Educational Resources Information Center

    Swets, Benjamin; Kurby, Christopher A.

    2016-01-01

    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…

  18. Exploring the Eye-Movement Patterns as Chinese Children Read Texts: A Developmental Perspective

    ERIC Educational Resources Information Center

    Chen, Minglei; Ko, Hwawei

    2011-01-01

    This study was to investigate Chinese children's eye patterns while reading different text genres from a developmental perspective. Eye movements were recorded while children in the second through sixth grades read two expository texts and two narrative texts. Across passages, overall word frequency was not significantly different between the two…

  19. The Use of Eye Movements in the Study of Multimedia Learning

    ERIC Educational Resources Information Center

    Hyona, Jukka

    2010-01-01

    This commentary focuses on the use of the eye-tracking methodology to study cognitive processes during multimedia learning. First, some general remarks are made about how the method is applied to investigate visual information processing, followed by a reflection on the eye movement measures employed in the studies published in this special issue.…

  20. Looking for Answers: Eye Movements in Non-Visual Cognitive Tasks

    ERIC Educational Resources Information Center

    Ehrlichman, Howard; Micic, Dragana; Sousa, Amber; Zhu, John

    2007-01-01

    It is not known why people move their eyes when engaged in non-visual cognition. The current study tested the hypothesis that differences in saccadic eye movement rate (EMR) during non-visual cognitive tasks reflect different requirements for searching long-term memory. Participants performed non-visual tasks requiring relatively low or high…

  1. 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…

  2. 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

  3. Visual Data Mining: An Exploratory Approach to Analyzing Temporal Patterns of Eye Movements

    ERIC Educational Resources Information Center

    Yu, Chen; Yurovsky, Daniel; Xu, Tian

    2012-01-01

    Infant eye movements are an important behavioral resource to understand early human development and learning. But the complexity and amount of gaze data recorded from state-of-the-art eye-tracking systems also pose a challenge: how does one make sense of such dense data? Toward this goal, this article describes an interactive approach based on…

  4. Removing the Interdependency between Horizontal and Vertical Eye-Movement Components in Electrooculograms.

    PubMed

    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

  5. Grammatical number processing and anticipatory eye movements are not tightly coordinated in English spoken language comprehension

    PubMed Central

    Riordan, Brian; Dye, Melody; Jones, Michael N.

    2015-01-01

    Recent studies of eye movements in world-situated language comprehension have demonstrated that rapid processing of morphosyntactic information – e.g., grammatical gender and number marking – can produce anticipatory eye movements to referents in the visual scene. We investigated how type of morphosyntactic information and the goals of language users in comprehension affected eye movements, focusing on the processing of grammatical number morphology in English-speaking adults. Participants’ eye movements were recorded as they listened to simple English declarative (There are the lions.) and interrogative (Where are the lions?) sentences. In Experiment 1, no differences were observed in speed to fixate target referents when grammatical number information was informative relative to when it was not. The same result was obtained in a speeded task (Experiment 2) and in a task using mixed sentence types (Experiment 3). We conclude that grammatical number processing in English and eye movements to potential referents are not tightly coordinated. These results suggest limits on the role of predictive eye movements in concurrent linguistic and scene processing. We discuss how these results can inform and constrain predictive approaches to language processing. PMID:25999900

  6. Eye movements of goldfish evoked by body tilting and linear acceleration

    NASA Astrophysics Data System (ADS)

    Iwata, K.; Takabayashi, A.; Mori, S.

    An otolith organ on ground behave as a detector of both gravity and linear acceleration, and play an important role in controlling posture and eye movement for tilt of the head or translational motion. On the other hand, a gravitational acceleration ingredient to an otolith organ disappears in microgravity environment. However, linear acceleration can be received by otolith organ and produce a sensation that is different from that on Earth. In this study, we examined function of otolith organ in goldfish revealed from analysis of eye movement induced by linear acceleration and/or the tilt of body. We analyzed both torsional and vertical eye movements from video images frame by frame. For tilting stimulation, torsional eye movements induced by head down was larger than that induced by head up. For acceleration stimulation, torsional eye movements induced during head down was larger than that induced during head up. These results suggest that otolith organ system has directional dependence and that body tilt and linear acceleration may not be with equivalent stimulation to cause eye movement on Earth.

  7. Learning from others: effects of viewing another person's eye movements while searching for chest nodules

    NASA Astrophysics Data System (ADS)

    Litchfield, Damien; Ball, Linden J.; Donovan, Tim; Manning, David J.; Crawford, Trevor

    2008-03-01

    We report a study that investigated whether experienced and inexperienced radiographers benefit from knowing where another person looked during pulmonary nodule detection. Twenty-four undergraduate radiographers (1 year of experience) and 24 postgraduate radiographers (5+ years of experience) searched 42 chest x-rays for nodules and rated how confident they were in their decisions. Eye movements were also recorded. Performance was compared across three within-participant conditions: (1) free search - where radiographers could identify nodules as normal; (2) image preview - where radiographers were first shown each chest x-ray for 20 seconds before they could then proceed to mark the location of any nodules; and (3) eye movement preview - which was identical to image preview except that the 20 second viewing period displayed an overlay of the real-time eye movements of another radiographer's scanpath for that image. For this preview condition half of each group were shown where a novice radiographer looked, and the other half were shown where an experienced radiologist looked. This was not made known to the participants until after the experiment. Performance was assessed using JAFROC analysis. Both groups of radiographers performed better in the eye movement preview condition compared with the image preview or free search conditions, with inexperienced radiographers improving the most. We discuss our findings in terms of the task-specific information interpreted from eye movement previews, task difficulty across images, and whether it matters if radiographers are previewing the eye movements of an expert or a novice.

  8. Age-related effects of increasing postural challenge on eye movement onset latencies to visual targets.

    PubMed

    Jimenez, Sergio; Hollands, Mark; Palmisano, Stephen; Kim, Juno; Markoulli, Maria; McAndrew, Darryl; Stamenkovic, Alexander; Walsh, Joel; Bos, Sophie; Stapley, Paul J

    2016-06-01

    When a single light cue is given in the visual field, our eyes orient towards it with an average latency of 200 ms. If a second cue is presented at or around the time of the response to the first, a secondary eye movement occurs that represents a reorientation to the new target. While studies have shown that eye movement latencies to 'single-step' targets may or may not be lengthened with age, secondary eye movements (during 'double-step' displacements) are significantly delayed with increasing age. The aim of this study was to investigate whether the postural challenge posed simply by standing (as opposed to sitting) results in significantly longer eye movement latencies in older adults compared to the young. Ten young (<35 years) and 10 older healthy adults (>65 years) participated in the study. They were required to fixate upon a central target and move their eyes in response to 2 types of stimuli: (1) a single-step perturbation of target position either 15° to the right or left and (2) a double-step target displacement incorporating an initial target jump to the right or left by 15°, followed after 200 ms, by a shift of target position to the opposite side (e.g. +15° then -15°). All target displacement conditions were executed in sit and stand positions with the participant at the same distance from the targets. Eye movements were recorded using electro-oculography. Older adults did not show significantly longer eye movement latencies than the younger adults for single-step target displacements, and postural configuration (stand compared to sit) had no effect upon latencies for either group. We categorised double-step trials into those during which the second light changed after or before the onset of the eye shift to the first light. For the former category, young participants showed faster secondary eye shifts to the second light in the standing position, while the older adults did not. For the latter category of double-step trial, young participants

  9. Effects of eye movement with functional electrical stimulation on balance in stroke patients with neglect syndrome

    PubMed Central

    Park, Si-Eun

    2016-01-01

    [Purpose] The aim of the present study was to determine whether eye movement in conjunction with functional electrical stimulation (FES) could improve balance ability in stroke patients with neglect syndrome. [Subjects and Methods] The subjects consisted of 15 stroke patients with neglect syndrome. The intervention was eye movement in conjunction with FES. The program was conducted 5 times per week, for 6 weeks. Static balance (eyes-open and eyes-closed) and dynamic balance were measured before and after testing. [Results] In measurement of static balance, subjects showed significant differences in sway length and sway area when examined in the eyes-open condition, but not the eyes-closed condition. In measurement of dynamic balance, the subjects showed significant differences in limit of stability (forward/backward and left/right). [Conclusion] These results indicate that eye movement in conjunction with FES had a positive effect on the static and dynamic balance in the eyes-open condition, but not in the eyes-closed condition of stroke patients with neglect syndrome. Further studies should therefore investigate various interventions in stroke patients with neglect syndrome. PMID:27313375

  10. Effects of eye movement with functional electrical stimulation on balance in stroke patients with neglect syndrome.

    PubMed

    Park, Si-Eun

    2016-05-01

    [Purpose] The aim of the present study was to determine whether eye movement in conjunction with functional electrical stimulation (FES) could improve balance ability in stroke patients with neglect syndrome. [Subjects and Methods] The subjects consisted of 15 stroke patients with neglect syndrome. The intervention was eye movement in conjunction with FES. The program was conducted 5 times per week, for 6 weeks. Static balance (eyes-open and eyes-closed) and dynamic balance were measured before and after testing. [Results] In measurement of static balance, subjects showed significant differences in sway length and sway area when examined in the eyes-open condition, but not the eyes-closed condition. In measurement of dynamic balance, the subjects showed significant differences in limit of stability (forward/backward and left/right). [Conclusion] These results indicate that eye movement in conjunction with FES had a positive effect on the static and dynamic balance in the eyes-open condition, but not in the eyes-closed condition of stroke patients with neglect syndrome. Further studies should therefore investigate various interventions in stroke patients with neglect syndrome. PMID:27313375

  11. Effects of the Linear Vestibulo-ocular Reflex on Accommodative Vergence Eye Movements

    PubMed Central

    Yakushin, Sergei B.; Kunin, Mikhail; Ogorodnikov, Dmitri; Cohen, Bernard; Raphan, Theodore

    2016-01-01

    The aim of the study was to determine whether accommodation to the relative motion of a target along the visual axis of one eye during fore–aft movement of the head could induce accurate vergence over a wide range of viewing distances and frequencies of oscillation, despite lack of vision in the second eye. This was compared to the vergence when both eyes viewed the target. Two rhesus monkeys were trained to fixate a visual target located 216–336 mm in front and along the visual axis of one eye, while being sinusoidally translated in the fore–aft direction. There was no movement of the seeing eye while the other eye converged, regardless of whether there was vision in the converged eye. Gain and phase of the convergence were determined based on the ratio of actual versus expected eye position if the target was accurately fixated. During translation at frequencies from 0.05 to 2 Hz, the eye converged on the target with an eye position gain of ≈1, and a phase close to zero. When vision was occluded in the converging eye, gains of convergence were 0.6–0.8 Hz up to 2 Hz, and the phases remained close to zero. At low frequencies of fore–aft movement, when the acceleration was negligible, convergence was driven by accommodation in the seeing eye. At higher frequencies, vergence could also be driven by the linear vestibulo-ocular reflex (lVOR). Thus, vision in one nonmoving eye and the lVOR combine to generate convergence over a wide range of frequencies and viewing distances. PMID:19645957

  12. What the Eyes Already "Know": Using Eye Movement Measurement to Tap into Children's Implicit Numerical Magnitude Representations

    ERIC Educational Resources Information Center

    Heine, Angela; Thaler, Verena; Tamm, Sascha; Hawelka, Stefan; Schneider, Michael; Torbeyns, Joke; De Smedt, Bert; Verschaffel, Lieven; Stern, Elsbeth; Jacobs, Arthur M.

    2010-01-01

    To date, a number of studies have demonstrated the existence of mismatches between children's "implicit" and "explicit" knowledge at certain points in development that become manifest by their gestures and gaze orientation in different problem solving contexts. Stimulated by this research, we used eye movement measurement to investigate the…

  13. Scanning technique for tracking small eye-movements

    NASA Technical Reports Server (NTRS)

    Kelly, D. H.; Crane, H. D.

    1972-01-01

    Scanning technique images spot of blue light on fundus, measures variations in reflectance of spot and compares reflectance pattern with a stored reference pattern. Method then converts the difference from stored pattern into infrared eye motion.

  14. Disk space and load time requirements for eye movement biometric databases

    NASA Astrophysics Data System (ADS)

    Kasprowski, Pawel; Harezlak, Katarzyna

    2016-06-01

    Biometric identification is a very popular area of interest nowadays. Problems with the so-called physiological methods like fingerprints or iris recognition resulted in increased attention paid to methods measuring behavioral patterns. Eye movement based biometric (EMB) identification is one of the interesting behavioral methods and due to the intensive development of eye tracking devices it has become possible to define new methods for the eye movement signal processing. Such method should be supported by an efficient storage used to collect eye movement data and provide it for further analysis. The aim of the research was to check various setups enabling such a storage choice. There were various aspects taken into consideration, like disk space usage, time required for loading and saving whole data set or its chosen parts.

  15. Listing's law for eye, head and arm movements and their synergistic control.

    PubMed

    Straumann, D; Haslwanter, T; Hepp-Reymond, M C; Hepp, K

    1991-01-01

    We have recorded eye, head, and upper arm rotations in five healthy human subjects using the three-dimensional search coil technique. Our measurements show that the coordination of eye and head movements during gaze shifts within +/- 25 deg relative to the forward direction is organized by restricting the rotatory trajectories of the two systems to almost parallel planes. These so-called "Listing planes" for eye-in-space and head-in-space rotations are workspace-oriented, not body-fixed. Eye and head trajectories in their respective planes are closely related in direction and amplitude. For pointing or grasping, the rotatory trajectories of the arm are also restricted to a workspace-oriented Listing plane. During visually guided movements, arm follows gaze, and the nine-dimensional rotatory configuration space for eye-head-arm-synergies (three degrees of freedom for each system) is reduced to a two-dimensional plane in the space of quaternion vectors. PMID:1756791

  16. 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. PMID:17984782

  17. 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

  18. 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

  19. Eye Movements and Abducens Motoneuron Behavior after Cholinergic Activation of the Nucleus Reticularis Pontis Caudalis

    PubMed Central

    Márquez-Ruiz, Javier; Escudero, Miguel

    2010-01-01

    Study Objectives: The aim of this work was to characterize eye movements and abducens (ABD) motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis (NRPC). Methods: Six female adult cats were prepared for chronic recording of eye movements (using the scleral search-coil technique), electroencephalography, electromyography, ponto-geniculo-occipital (PGO) waves in the lateral geniculate nucleus, and ABD motoneuron activities after microinjections of the cholinergic agonist carbachol into the NRPC. Results: Unilateral microinjections of carbachol in the NRPC induced tonic and phasic phenomena in the oculomotor system. Tonic effects consisted of ipsiversive rotation to the injected side, convergence, and downward rotation of the eyes. Phasic effects consisted of bursts of rhythmic rapid eye movements directed contralaterally to the injected side along with PGO-like waves in the lateral geniculate and ABD nuclei. Although tonic effects were dependent on the level of drowsiness, phasic effects were always present and appeared along with normal saccades when the animal was vigilant. ABD motoneurons showed phasic activities associated with ABD PGO-like waves during bursts of rapid eye movements, and tonic and phasic activities related to eye position and velocity during alertness. Conclusion The cholinergic activation of the NRPC induces oculomotor phenomena that are somewhat similar to those described during REM sleep. A precise comparison of the dynamics and timing of the eye movements further suggests that a temporal organization of both NRPCs is needed to reproduce the complexity of the oculomotor behavior during REM sleep. Citation: Márquez-Ruiz J; Escudero M. Eye movements and abducens motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis. SLEEP 2010;33(11):1517-1527. PMID:21102994

  20. Hypoglycemia-induced spontaneous unilateral jerking movement in bilateral internal capsule posterior limb abnormalities.

    PubMed

    Nakajima, Nobuhito; Ueda, Masayuki; Nagayama, Hiroshi; Katayama, Yasuo

    2014-03-15

    We report an 89-year-old woman who developed consciousness disturbance associated with marked hypoglycemia, and showed involuntary movements manifested as spontaneous quick-jerking flexion followed by slow relaxation, in the right leg. Diffusion-weighted imaging revealed bilateral hyperintensities in the posterior limbs of the internal capsule (P-IC). She was treated with intravenous glucose supplementation, and her symptoms dramatically improved. The P-IC lesions are common abnormalities on MRI in hypoglycemia, and may cause paralysis. However involuntary movements associated with the lesions are rarely observed. The spontaneous jerking movements observed in this patient might result from transient impairment of the pyramidal tract associated with hypoglycemia. PMID:24411408

  1. Quantifying the Correlation Between Eye-Movement and Perceptual Responses to Moving Plaids

    NASA Technical Reports Server (NTRS)

    Beutter, Brent R.; Stone, L. S.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    To determine the extent to which the pursuit eye-movement and perceptual systems share a common neural motion-processing pathway, we simultaneously measure the psychophysical and eye-movement responses to drifting plaids in a direction-discrimination task. Correlation between the noise in the eye movements and percepts would suggest a shared neural substrate. Three observers were asked to track a plaid (Type I 90 deg; TF = 4 Hz, SF = 0.6 c/d; direction = -2, 0, or 2 deg), and to respond whether the motion was to the right or left of vertical. The eye-movement direction is computed from the initial 300 ms of saccade-free tracking (near open-loop). On each trial, we use the eye-movement direction to predict the perceptual response. We then compute the probability of successfully predicting the observer's response. We also use SOC analysis as an alternate measure of the correlation. We compare the data from both these analyses to the predictions of two models in which the eye movements and the percept are driven by either a common noisy signal (correlated model) or by two separate noisy signals (uncorrelated model). We also allow for the fact that our measured eye movements are degraded by eye-tracker noise. This noise causes our measured correlation to be lower than the actual biological correlation. The correlations in our data are higher than those predicted by the uncorrelated model, and are similar to the predictions of the correlated model. The proportion of perceptual responses correctly predicted by the eye movements were 0.66, 0.60, 0.73 for the -2, 0, 2 deg stimuli respectively (correlated model 0.65, 0.60, 0.70; uncorrelated model 0.58, 0.51, 0.60).The SOC proportions were 0.71, 0.64, 0.72 (correlated model 0.66, 0.64, 0.69; uncorrelated model 0.5, 0.5, 0.5). These results show that the oculomotor and perceptual system share a performance-limiting noise source and provide strong evidence that a common neural mechanism (perhaps MT or MST) drives both

  2. Dissociated vertical deviation: an exaggerated normal eye movement used to damp cyclovertical latent nystagmus.

    PubMed Central

    Guyton, D L; Cheeseman, E W; Ellis, F J; Straumann, D; Zee, D S

    1998-01-01

    PURPOSE: Dissociated vertical deviation (DVD) has eluded explanation for more than a century. The purpose of this study has been to elucidate the etiology and mechanism of DVD. METHODS: Eye movement recordings of six young adults with DVD were made with dual-coil scleral search coils under various conditions of fixation, illumination, and head tilt. Horizontal, vertical, and torsional eye movements were recorded for both eyes simultaneously. Analyses of the simultaneous vertical and torsional movements occurring during the DVD response were used to separate and identify the component vergence and version eye movements involved. RESULTS: Typically, both horizontal and cyclovertical latent nystagmus developed upon occlusion of either eye. A cycloversion then occurred, with the fixing eye intorting and tending to depress, the covered eye extorting and elevating. Simultaneously, upward versions occurred for the maintenance of fixation, consisting variously of saccades and smooth eye movements, leading to further elevation of the eye behind the cover. The cyclovertical component of the latent nystagmus became partially damped as the DVD developed. CONCLUSIONS: In patients with an early-onset defect of binocular function, the occlusion of one eye, or even concentration on fixing with one eye, produces unbalanced input to the vestibular system. This results in latent nystagmus, sometimes seen only with magnification. The cyclovertical component of the latent nystagmus, when present, is similar to normal vestibular nystagmus induced by dynamic head tilting about an oblique axis. Such vestibular nystagmus characteristically produces a hyperdeviation of the eyes. In the case of cyclovertical latent nystagmus, the analogous hyperdeviation will persist unless corrected by a vertical vergence. A normal, oblique-muscle-mediated, cycloversion/vertical vergence is called into play. This occurs in the proper direction to correct the hyperdeviation, but it occurs in an exaggerated

  3. Abnormal movements in first-episode, nonaffective psychosis: dyskinesias, stereotypies, and catatonic-like signs.

    PubMed

    Compton, Michael T; Fantes, Francisco; Wan, Claire Ramsay; Johnson, Stephanie; Walker, Elaine F

    2015-03-30

    Motor abnormalities represent a neurobehavioral domain of signs intrinsic to schizophrenia-spectrum disorders, though they are commonly attributed to medication side effects and remain understudied. Individuals with first-episode psychosis represent an ideal group to study innate movement disorders due to minimal prior antipsychotic exposure. We measured dyskinesias, stereotypies, and catatonic-like signs and examined their associations with: (1) age at onset of psychotic symptoms and duration of untreated psychosis; (2) positive, negative, and disorganized symptoms; (3) neurocognition; and (4) neurological soft signs. Among 47 predominantly African American first-episode psychosis patients in a public-sector hospital, the presence and severity of dyskinesias, stereotypies, and catatonic-like features were assessed using approximately 30-min video recordings. Movement abnormalities were rated utilizing three scales (Dyskinesia Identification System Condensed User Scale, Stereotypy Checklist, and Catatonia Rating Scale). Correlational analyses were conducted. Scores for each of three movement abnormality types were modestly inter-correlated (r=0.29-0.40). Stereotypy score was significantly associated with age at onset of psychotic symptoms (r=0.32) and positive symptom severity scores (r=0.29-0.41). There were no meaningful or consistent associations with negative symptom severity, neurocognition, or neurological soft signs. Abnormal movements appear to represent a relatively distinct phenotypic domain deserving of further research. PMID:25619434

  4. Occipital gamma-oscillations modulated during eye movement tasks: simultaneous eye tracking and electrocorticography recording in epileptic patients.

    PubMed

    Nagasawa, Tetsuro; Matsuzaki, Naoyuki; Juhász, Csaba; Hanazawa, Akitoshi; Shah, Aashit; Mittal, Sandeep; Sood, Sandeep; Asano, Eishi

    2011-10-15

    We determined the spatio-temporal dynamics of cortical gamma-oscillations modulated during eye movement tasks, using simultaneous eye tracking and intracranial electrocorticography (ECoG) recording. Patients with focal epilepsy were instructed to follow a target moving intermittently and unpredictably from one place to another either in an instantaneous or smooth fashion during extraoperative ECoG recording. Target motion elicited augmentation of gamma-oscillations in the lateral, inferior and polar occipital regions in addition to portions of parietal and frontal regions; subsequent voluntary eye movements elicited gamma-augmentation in the medial occipital region. Such occipital gamma-augmentations could not be explained by contaminations of ocular or myogenic artifacts. The degree of gamma-augmentation was generally larger during saccade compared to pursuit trials, while a portion of the polar occipital region showed pursuit-preferential gamma-augmentations. In addition to the aforementioned eye movement task, patients were asked to read a single word popping up on the screen. Gamma-augmentation was elicited in widespread occipital regions following word presentation, while gamma-augmentation in the anterior portion of the medial occipital region was elicited by an involuntary saccade following word presentation rather than word presentation itself. Gamma-augmentation in the lateral, inferior and polar occipital regions can be explained by increased attention to a moving target, whereas gamma-augmentation in the anterior-medial occipital region may be elicited by images in the peripheral field realigned following saccades. In functional studies comparing brain activation between two tasks, eye movement patterns during tasks may need to be considered as confounding factors. PMID:21816225

  5. Role of movement in long-term basal ganglia changes: implications for abnormal motor responses

    PubMed Central

    Simola, Nicola; Morelli, Micaela; Frazzitta, Giuseppe; Frau, Lucia

    2013-01-01

    Abnormal involuntary movements (AIMs) and dyskinesias elicited by drugs that stimulate dopamine receptors in the basal ganglia are a major issue in the management of Parkinson’s disease (PD). Preclinical studies in dopamine-denervated animals have contributed to the modeling of these abnormal movements, but the precise neurochemical and functional mechanisms underlying these untoward effects are still elusive. It has recently been suggested that the performance of movement may itself promote the later emergence of drug-induced motor complications, by favoring the generation of aberrant motor memories in the dopamine-denervated basal ganglia. Our recent results from hemiparkinsonian rats subjected to the priming model of dopaminergic stimulation are in agreement with this. These results demonstrate that early performance of movement is crucial for the manifestation of sensitized rotational behavior, indicative of an abnormal motor response, and neurochemical modifications in selected striatal neurons following a dopaminergic challenge. Building on this evidence, this paper discusses the possible role of movement performance in drug-induced motor complications, with a look at the implications for PD management. PMID:24167489

  6. Quantitative Study on the Effect of Abnormalities on Respiration-Induced Kidney Movement.

    PubMed

    Abhilash, Rakkunedeth H; Chauhan, Sunita; Che, Ma Voon; Ooi, Chin-Chin; Bakar, Rafidah Abu; Lo, Richard H G

    2016-07-01

    Respiration-induced movement of abdominal organs hampers the targeting accuracy of non-invasive surgical techniques such as focused ultrasound surgery and radiosurgery. Unaccounted organ movement can result in either under dosage or damage to intervening healthy tissues. The respiration-induced movement is known to be significantly large in kidneys; however, the impact of abnormalities such as tumors and cysts on kidney movement is poorly understood. In this study, we quantified the movement patterns of kidneys in 48 normal and 62 affected kidneys (43 calcified cysts, 11 angiomyolipomas, 4 renal cell carcinomas and 4 polycystic kidneys) using ultrasound and simultaneously tracked the respiratory movement patterns using a stereo camera system. The kidneys were localized from 2-D ultrasound sequences using a template matching technique. The average movements of the right and left kidneys were, respectively, 24.54 ± 6.4 and 17.06 ± 3.66 mm in the superior-inferior and 13.62 ± 3.71 and 9.80 ± 3.32 mm in the transverse directions. Average movement in the superior-inferior direction of normal kidneys was greater than that of affected kidneys for both right (26.9 ± 5.1 vs. 22.6 ± 3.3, p < 0.001) and left (17.8 ± 2.5 vs. 16.1 ± 4.2, p = 0.01) kidneys. On the basis of spatial extent of abnormality, affected kidneys were categorized as category A (<10 mm in 26 patients), category B (10-20 mm in 22 patients) and category C (>20 mm in 14 patients). Compared with normal patients, the extent of movement was significantly reduced in abnormal categories B (p < 0.001) and C (p < 0.001), but the change was not significant in category A (p = 0.04). Hysteresis plots of the kidneys revealed a maximum change of 12.3 mm. The movement patterns of the kidneys also closely correlated with the respiratory movement pattern (Pearson correlation = 0.89 [right] and 0.87 [left]). We expect that the movement pattern analyses and quantification carried out

  7. Eye-movements intervening between two successive sounds disrupt comparisons of auditory location

    PubMed Central

    Pavani, Francesco; Husain, Masud; Driver, Jon

    2008-01-01

    Summary Many studies have investigated how saccades may affect the internal representation of visual locations across eye-movements. Here we studied instead whether eye-movements can affect auditory spatial cognition. In two experiments, participants judged the relative azimuth (same/different) of two successive sounds presented from a horizontal array of loudspeakers, separated by a 2.5 secs delay. Eye-position was either held constant throughout the trial (being directed in a fixed manner to the far left or right of the loudspeaker array), or had to be shifted to the opposite side of the array during the retention delay between the two sounds, after the first sound but before the second. Loudspeakers were either visible (Experiment1) or occluded from sight (Experiment 2). In both cases, shifting eye-position during the silent delay-period affected auditory performance in the successive auditory comparison task, even though the auditory inputs to be judged were equivalent. Sensitivity (d′) for the auditory discrimination was disrupted, specifically when the second sound shifted in the opposite direction to the intervening eye-movement with respect to the first sound. These results indicate that eye-movements affect internal representation of auditory location. PMID:18566808

  8. Eye Movements during Auditory Attention Predict Individual Differences in Dorsal Attention Network Activity

    PubMed Central

    Braga, Rodrigo M.; Fu, Richard Z.; Seemungal, Barry M.; Wise, Richard J. S.; Leech, Robert

    2016-01-01

    The neural mechanisms supporting auditory attention are not fully understood. A dorsal frontoparietal network of brain regions is thought to mediate the spatial orienting of attention across all sensory modalities. Key parts of this network, the frontal eye fields (FEF) and the superior parietal lobes (SPL), contain retinotopic maps and elicit saccades when stimulated. This suggests that their recruitment during auditory attention might reflect crossmodal oculomotor processes; however this has not been confirmed experimentally. Here we investigate whether task-evoked eye movements during an auditory task can predict the magnitude of activity within the dorsal frontoparietal network. A spatial and non-spatial listening task was used with on-line eye-tracking and functional magnetic resonance imaging (fMRI). No visual stimuli or cues were used. The auditory task elicited systematic eye movements, with saccade rate and gaze position predicting attentional engagement and the cued sound location, respectively. Activity associated with these separate aspects of evoked eye-movements dissociated between the SPL and FEF. However these observed eye movements could not account for all the activation in the frontoparietal network. Our results suggest that the recruitment of the SPL and FEF during attentive listening reflects, at least partly, overt crossmodal oculomotor processes during non-visual attention. Further work is needed to establish whether the network’s remaining contribution to auditory attention is through covert crossmodal processes, or is directly involved in the manipulation of auditory information. PMID:27242465

  9. Anticipatory Effects of Intonation: Eye Movements during Instructed Visual Search

    ERIC Educational Resources Information Center

    Ito, Kiwako; Speer, Shari R.

    2008-01-01

    Three eye-tracking experiments investigated the role of pitch accents during online discourse comprehension. Participants faced a grid with ornaments, and followed prerecorded instructions such as "Next, hang the blue ball" to decorate holiday trees. Experiment 1 demonstrated a processing advantage for felicitous as compared to infelicitous uses…

  10. Metric Issues in the Study of Eye Movements in Psychiatry

    ERIC Educational Resources Information Center

    Smyrnis, Nikolaos

    2008-01-01

    This review provides a description of the measurement methods, task definitions and measurement parameters in the study of smooth eye pursuit and saccade-antisaccade tasks in psychiatry. The large heterogeneity in task definitions and definitions of parameters and its potential impact on the large variability of the parameter measures is…

  11. Eye Movements Reveal the Dynamic Simulation of Speed in Language

    ERIC Educational Resources Information Center

    Speed, Laura J.; Vigliocco, Gabriella

    2014-01-01

    This study investigates how speed of motion is processed in language. In three eye-tracking experiments, participants were presented with visual scenes and spoken sentences describing fast or slow events (e.g., "The lion ambled/dashed to the balloon"). Results showed that looking time to relevant objects in the visual scene was affected…

  12. Eye Movements and Display Change Detection during Reading

    ERIC Educational Resources Information Center

    Slattery, Timothy J.; Angele, Bernhard; Rayner, Keith

    2011-01-01

    In the boundary change paradigm (Rayner, 1975), when a reader's eyes cross an invisible boundary location, a preview word is replaced by a target word. Readers are generally unaware of such changes due to saccadic suppression. However, some readers detect changes on a few trials and a small percentage of them detect many changes. Two experiments…

  13. Eye Movements during Spoken Word Recognition in Russian Children

    ERIC Educational Resources Information Center

    Sekerina, Irina A.; Brooks, Patricia J.

    2007-01-01

    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…

  14. Metaphorical Salience in Artistic Text Processing: Evidence From Eye Movement.

    PubMed

    Novikova, Eleonora G; Janyan, Armina; Tsaregorodtseva, Oksana V

    2015-01-01

    The study aimed to explore processing difference between a literal phrase and a metaphoric one. Unlike artificially created stimuli in most experimental research, an artistic text with an ambiguous binary metaphoric phrase was used. Eye tracking methodology was applied. Results suggested difference between the two types of phrases in both early and late processing measures. PMID:26562923

  15. Vestibulo-Cervico-Ocular Responses and Tracking Eye Movements after Prolonged Exposure to Microgravity

    NASA Technical Reports Server (NTRS)

    Kornilova, L. N.; Naumov, I. A.; Azarov, K. A.; Sagalovitch, S. V.; Reschke, Millard F.; Kozlovskaya, I. B.

    2007-01-01

    The vestibular function and tracking eye movements were investigated in 12 Russian crew members of ISS missions on days 1(2), 4(5-6), and 8(9-10) after prolonged exposure to microgravity (126 to 195 days). The spontaneous oculomotor activity, static torsional otolith-cervico-ocular reflex, dynamic vestibulo-cervico-ocular responses, vestibular reactivity, tracking eye movements, and gaze-holding were studied using videooculography (VOG) and electrooculography (EOG) for parallel eye movement recording. On post-flight days 1-2 (R+1-2) some cosmonauts demonstrated: - an increased spontaneous oculomotor activity (floating eye movements, spontaneous nystagmus of the typical and atypical form, square wave jerks, gaze nystagmus) with the head held in the vertical position; - suppressed otolith function (absent or reduced by one half amplitude of torsional compensatory eye counter-rolling) with the head inclined statically right- or leftward by 300; - increased vestibular reactivity (lowered threshold and increased intensity of the vestibular nystagmus) during head turns around the longitudinal body axis at 0.125 Hz; - a significant change in the accuracy, velocity, and temporal characteristics of the eye tracking. The pattern, depth, dynamics, and velocity of the vestibular function and tracking eye movements recovery varied with individual participants in the investigation. However, there were also regular responses during readaptation to the normal gravity: - suppression of the otolith function was typically accompanied by an exaggerated vestibular reactivity; - the structure of visual tracking (the accuracy of fixational eye rotations, smooth tracking, and gaze-holding) was disturbed (the appearance of correcting saccades, the transition of smooth tracking to saccadic tracking) only in those cosmonauts who, in parallel to an increased reactivity of the vestibular input, also had central changes in the oculomotor system (spontaneous nystagmus, gaze nystagmus).

  16. Effects of word length on eye movement control: The evidence from Arabic.

    PubMed

    Paterson, Kevin B; Almabruk, Abubaker A A; McGowan, Victoria A; White, Sarah J; Jordan, Timothy R

    2015-10-01

    The finding that word length plays a fundamental role in determining where and for how long readers fixate within a line of text has been central to the development of sophisticated models of eye movement control. However, research in this area is dominated by the use of Latinate languages (e.g., English, French, German), and little is known about eye movement control for alphabetic languages with very different visual characteristics. To address this issue, the present experiment undertook a novel investigation of the influence of word length on eye movement behavior when reading Arabic. Arabic is an alphabetic language that not only is read from right to left but has visual characteristics fundamentally different from Latinate languages, and so is ideally suited to testing the generality of mechanisms of eye movement control. The findings reveal that readers were more likely to fixate and refixate longer words, and also that longer words tended to be fixated for longer. In addition, word length influenced the landing positions of initial fixations on words, with the effect that readers fixated the center of short words and fixated closer to the beginning letters for longer words, and the location of landing positions affected both the duration of the first fixation and probability of refixating the word. The indication now, therefore, is that effects of word length are a widespread and fundamental component of reading and play a central role in guiding eye-movement behavior across a range of very different alphabetic systems. PMID:25690581

  17. 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. PMID:24391304

  18. A role of the human thalamus in predicting the perceptual consequences of eye movements

    PubMed Central

    Ostendorf, Florian; Liebermann, Daniela; Ploner, Christoph J.

    2013-01-01

    Internal monitoring of oculomotor commands may help to anticipate and keep track of changes in perceptual input imposed by our eye movements. Neurophysiological studies in non-human primates identified corollary discharge (CD) signals of oculomotor commands that are conveyed via thalamus to frontal cortices. We tested whether disruption of these monitoring pathways on the thalamic level impairs the perceptual matching of visual input before and after an eye movement in human subjects. Fourteen patients with focal thalamic stroke and 20 healthy control subjects performed a task requiring a perceptual judgment across eye movements. Subjects reported the apparent displacement of a target cue that jumped unpredictably in sync with a saccadic eye movement. In a critical condition of this task, six patients exhibited clearly asymmetric perceptual performance for rightward vs. leftward saccade direction. Furthermore, perceptual judgments in seven patients systematically depended on oculomotor targeting errors, with self-generated targeting errors erroneously attributed to external stimulus jumps. Voxel-based lesion-symptom mapping identified an area in right central thalamus as critical for the perceptual matching of visual space across eye movements. Our findings suggest that trans-thalamic CD transmission decisively contributes to a correct prediction of the perceptual consequences of oculomotor actions. PMID:23630474

  19. Decorrelation of retinal response to natural scenes by fixational eye movements

    PubMed Central

    Segal, Irina Yonit; Giladi, Chen; Gedalin, Michael; Rucci, Michele; Ben-Tov, Mor; Kushinsky, Yam; Mokeichev, Alik; Segev, Ronen

    2015-01-01

    Under natural viewing conditions the input to the retina is a complex spatiotemporal signal that depends on both the scene and the way the observer moves. It is commonly assumed that the retina processes this input signal efficiently by taking into account the statistics of the natural world. It has recently been argued that incessant microscopic eye movements contribute to this process by decorrelating the input to the retina. Here we tested this theory by measuring the responses of the salamander retina to stimuli replicating the natural input signals experienced by the retina in the presence and absence of fixational eye movements. Contrary to the predictions of classic theories of efficient encoding that do not take behavior into account, we show that the response characteristics of retinal ganglion cells are not sufficient in themselves to disrupt the broad correlations of natural scenes. Specifically, retinal ganglion cells exhibited strong and extensive spatial correlations in the absence of fixational eye movements. However, the levels of correlation in the neural responses dropped in the presence of fixational eye movements, resulting in effective decorrelation of the channels streaming information to the brain. These observations confirm the predictions that microscopic eye movements act to reduce correlations in retinal responses and contribute to visual information processing. PMID:25713370

  20. Patterns of cortical thinning in idiopathic rapid eye movement sleep behavior disorder.

    PubMed

    Rahayel, Shady; Montplaisir, Jacques; Monchi, Oury; Bedetti, Christophe; Postuma, Ronald B; Brambati, Simona; Carrier, Julie; Joubert, Sven; Latreille, Véronique; Jubault, Thomas; Gagnon, Jean-François

    2015-04-15

    Idiopathic rapid eye movement sleep behavior disorder is a parasomnia that is a risk factor for dementia with Lewy bodies and Parkinson's disease. Brain function impairments have been identified in this disorder, mainly in the frontal and posterior cortical regions. However, the anatomical support for these dysfunctions remains poorly understood. We investigated gray matter thickness, gray matter volume, and white matter integrity in patients with idiopathic rapid eye movement sleep behavior disorder. Twenty-four patients with polysomnography-confirmed idiopathic rapid eye movement sleep behavior disorder and 42 healthy individuals underwent a 3-tesla structural and diffusion magnetic resonance imaging examination using corticometry, voxel-based morphometry, and diffusion tensor imaging. In the patients with idiopathic rapid eye movement sleep behavior disorder, decreased cortical thickness was observed in the frontal cortex, the lingual gyrus, and the fusiform gyrus. Gray matter volume was reduced in the superior frontal sulcus only. Patients showed no increased gray matter thickness or volume. Diffusion tensor imaging analyses revealed no significant white matter differences between groups. Using corticometry in patients with idiopathic rapid eye movement sleep behavior disorder, several new cortical regions with gray matter alterations were identified, similar to those reported in dementia with Lewy bodies and Parkinson's disease. These findings provide some anatomical support for previously identified brain function impairments in this disorder. PMID:24676967

  1. Correlation of climbing perception and eye movements during daytime and nighttime takeoffs using a flight simulator.

    PubMed

    Tamura, Atsushi; Wada, Yoshiro; Shimizu, Naoki; Inui, Takuo; Shiotani, Akihiro

    2016-05-01

    Conclusion This study suggests that the subjective climbing perception can be quantitatively evaluated using values calculated from induced eye movements, and the findings may aid in the detection of pilots who are susceptible to spatial disorientation in a screening test. Objective The climbing perception experienced by a pilot during takeoff at night is stronger than that experienced during the day. To investigate this illusion, this study assessed eye movements and analyzed their correlation with subjective climbing perception during daytime and nighttime takeoffs. Methods Eight male volunteers participated in this study. A simulated aircraft takeoff environment was created using a flight simulator and the maximum slow-phase velocities and vestibulo-ocular reflex gain of vertical eye movements were calculated during takeoff simulation. Results Four of the eight participants reported that their perception of climbing at night was stronger, while the other four reported that there was no difference between day and night. These perceptions were correlated with eye movements; participants with a small difference in the maximum slow-phase velocities of their downward eye movements between daytime and nighttime takeoffs indicated that their perception of climbing was the same under the two conditions. PMID:26808614

  2. 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

  3. Tonic eye movements induced by bilateral and unilateral galvanic vestibular stimulation (GVS) in guinea pigs.

    PubMed

    Kim, Juno

    2013-01-01

    Galvanic vestibular stimulation (GVS) stimulates primary vestibular afferents innervating the semicircular canals (SCCs) and otoliths found in the inner ear of humans and other mammals, including guinea pigs. To determine which pathways contribute to eye movements generated by this artificial vestibular stimulation in guinea pigs, low current intensities of GVS were passed either bilaterally between the tensor-tympani muscles of the two ears (up to 30 μA) or unilaterally between one tensor-tympani electrode and an indifferent on the back of the neck (up to 60 μA). Both forms of GVS were found to selectively generate tonic eye movements without nystagmus, characteristic of the otolith-ocular reflex; the axis of eye rotation did not align with any semicircular canal plane, but was oriented close to the expected axis of eye rotation that would occur in response to the net stimulation of otolith afferents. The induced eye rotation was predominantly vertical with a smaller horizontal deviation and very little torsion. Consistent with the results of previous human studies, the tonic eye movements were found to exhibit bilateral gain enhancement, whereby bilateral GVS generated twice the amplitude of eye rotation as unilateral anodal or cathodal stimulation alone. Eye movement responses to unilateral GVS were symmetrical in amplitude during equivalent intensities of anodal and cathodal stimulation, consistent with the known responses of more regularly and intermediately discharging primary vestibular afferents to GVS. These results together suggest that more regularly discharging otolith-ocular projections may mediate the tonic changes in eye position induced during maintained, low-intensity GVS in guinea pigs. PMID:23022577

  4. Progress in elucidating the pathophysiological basis of nonrapid eye movement parasomnias: not yet informing therapeutic strategies.

    PubMed

    Horváth, András; Papp, Anikó; Szűcs, Anna

    2016-01-01

    Nonrapid eye movement (NREM) or arousal parasomnias are prevalent conditions in children and young adults, apparently provoked by any medical, physical, mental, or pharmacologic/toxic agent disturbing normal biorhythm and causing sleep fragmentation or abundant amount of slow wave sleep. The nadir and the ascending slope of the first sleep cycle of night sleep are the typical periods when NREM parasomnias, especially sleepwalking may occur on sleep-microstructural level; microarousals are the typical moments allowing NREM parasomnias. While sleep-disturbing factors have a clear precipitating effect, a genetic predisposition appears necessary in most cases. A candidate gene for sleepwalking has been identified on chromosome 20q12-q13.12 in one sleepwalking family. NREM parasomnias have a genetic and clinical link with nocturnal-frontal lobe epilepsies; possibly through an abnormality of the acetylcholine-related sleep-control system. The association of NREM parasomnias with the human leukocyte antigen system might be the sign of an autoimmune background to be further clarified. In the treatment of arousal parasomnias, the main tools are adequate sleep hygiene and the management of underlying conditions. Their pharmacotherapy has remained unresolved; the best options are clonazepam and some of the antidepressants, while a psychotherapy approach is also justified. PMID:27022307

  5. Visual and Vestibular Induced Eye Movements in Verbal Children and Adults with Autism.

    PubMed

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

    2015-12-01

    This study assessed the functionality of vestibular, pursuit, and saccade circuitry in autism across a wide age range. 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. 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. 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

  6. Idiopathic rapid eye movement sleep behaviour disorder: diagnosis, management, and the need for neuroprotective interventions.

    PubMed

    Iranzo, Alex; Santamaria, Joan; Tolosa, Eduardo

    2016-04-01

    Idiopathic rapid eye movement (REM) sleep behaviour disorder (IRBD) manifests as unpleasant dreams and vigorous behaviours during REM sleep that can result in injuries. Patients with IRBD have no known neurological diseases or motor or cognitive complaints; however, this sleep disorder is not harmless. In most cases, IRBD is the prelude of the synucleinopathies Parkinson's disease, dementia with Lewy bodies, or, less frequently, multiple system atrophy. Patients can show abnormalities that are characteristic of the synucleinopathies, and longitudinal follow-up shows that most patients develop parkinsonism and cognitive impairments with time. Thus, diagnosis of IRBD needs to be accurate and involves informing the patient of the risk of developing a neurodegenerative disease. It is extraordinary for a sleep disorder to precede the full expression of a neurodegenerative disease, which renders IRBD of particular interest in studies of the prodromal stage of the synucleinopathies, and in the development of neuroprotective interventions to stop or slow neurodegenerative deterioration before motor and cognitive symptomatology emerges. Such therapeutics do not currently exist, and thus represent an unmet need in IRBD. PMID:26971662

  7. Progress in elucidating the pathophysiological basis of nonrapid eye movement parasomnias: not yet informing therapeutic strategies

    PubMed Central

    Horváth, András; Papp, Anikó; Szűcs, Anna

    2016-01-01

    Nonrapid eye movement (NREM) or arousal parasomnias are prevalent conditions in children and young adults, apparently provoked by any medical, physical, mental, or pharmacologic/toxic agent disturbing normal biorhythm and causing sleep fragmentation or abundant amount of slow wave sleep. The nadir and the ascending slope of the first sleep cycle of night sleep are the typical periods when NREM parasomnias, especially sleepwalking may occur on sleep-microstructural level; microarousals are the typical moments allowing NREM parasomnias. While sleep-disturbing factors have a clear precipitating effect, a genetic predisposition appears necessary in most cases. A candidate gene for sleepwalking has been identified on chromosome 20q12-q13.12 in one sleepwalking family. NREM parasomnias have a genetic and clinical link with nocturnal-frontal lobe epilepsies; possibly through an abnormality of the acetylcholine-related sleep-control system. The association of NREM parasomnias with the human leukocyte antigen system might be the sign of an autoimmune background to be further clarified. In the treatment of arousal parasomnias, the main tools are adequate sleep hygiene and the management of underlying conditions. Their pharmacotherapy has remained unresolved; the best options are clonazepam and some of the antidepressants, while a psychotherapy approach is also justified. PMID:27022307

  8. EALab (Eye Activity Lab): a MATLAB Toolbox for Variable Extraction, Multivariate Analysis and Classification of Eye-Movement Data.

    PubMed

    Andreu-Perez, Javier; Solnais, Celine; Sriskandarajah, Kumuthan

    2016-01-01

    Recent advances in the reliability of the eye-tracking methodology as well as the increasing availability of affordable non-intrusive technology have opened the door to new research opportunities in a variety of areas and applications. This has raised increasing interest within disciplines such as medicine, business and education for analysing human perceptual and psychological processes based on eye-tracking data. However, most of the currently available software requires programming skills and focuses on the analysis of a limited set of eye-movement measures (e.g., saccades and fixations), thus excluding other measures of interest to the classification of a determined state or condition. This paper describes 'EALab', a MATLAB toolbox aimed at easing the extraction, multivariate analysis and classification stages of eye-activity data collected from commercial and independent eye trackers. The processing implemented in this toolbox enables to evaluate variables extracted from a wide range of measures including saccades, fixations, blinks, pupil diameter and glissades. Using EALab does not require any programming and the analysis can be performed through a user-friendly graphical user interface (GUI) consisting of three processing modules: 1) eye-activity measure extraction interface, 2) variable selection and analysis interface, and 3) classification interface. PMID:26358034

  9. Monkey superior colliculus represents rapid eye movements in a two-dimensional motor map.

    PubMed

    Hepp, K; Van Opstal, A J; Straumann, D; Hess, B J; Henn, V

    1993-03-01

    1. Although the eye has three rotational degrees of freedom, eye positions, during fixations, saccades, and smooth pursuit, with the head stationary and upright, are constrained to a plane by Listing's law. We investigated whether Listing's law for rapid eye movements is implemented at the level of the deeper layers of the superior colliculus (SC). 2. In three alert rhesus monkeys we tested whether the saccadic motor map of the SC is two dimensional, representing oculocentric target vectors (the vector or V-model), or three dimensional, representing the coordinates of the rotation of the eye from initial to final position (the quaternion or Q-model). 3. Monkeys made spontaneous saccadic eye movements both in the light and in the dark. They were also rotated about various axes to evoke quick phases of vestibular nystagmus, which have three degrees of freedom. Eye positions were measured in three dimensions with the magnetic search coil technique. 4. While the monkey made spontaneous eye movements, we electrically stimulated the deeper layers of the SC and elicited saccades from a wide range of initial positions. According to the Q-model, the torsional component of eye position after stimulation should be uniquely related to saccade onset position. However, stimulation at 110 sites induced no eye torsion, in line with the prediction of the V-model. 5. Activity of saccade-related burst neurons in the deeper layers of the SC was analyzed during rapid eye movements in three dimensions. No systematic eye-position dependence of the movement fields, as predicted by the Q-model, could be detected for these cells. Instead, the data fitted closely the predictions made by the V-model. 6. In two monkeys, both SC were reversibly inactivated by symmetrical bilateral injections of muscimol. The frequency of spontaneous saccades in the light decreased dramatically. Although the remaining spontaneous saccades were slow, Listing's law was still obeyed, both during fixations and

  10. Trajectory prediction of saccadic eye movements using a compressed exponential model

    PubMed Central

    Han, Peng; Saunders, Daniel R.; Woods, Russell L.; Luo, Gang

    2013-01-01

    Gaze-contingent display paradigms play an important role in vision research. The time delay due to data transmission from eye tracker to monitor may lead to a misalignment between the gaze direction and image manipulation during eye movements, and therefore compromise the contingency. We present a method to reduce this misalignment by using a compressed exponential function to model the trajectories of saccadic eye movements. Our algorithm was evaluated using experimental data from 1,212 saccades ranging from 3° to 30°, which were collected with an EyeLink 1000 and a Dual-Purkinje Image (DPI) eye tracker. The model fits eye displacement with a high agreement (R2 > 0.96). When assuming a 10-millisecond time delay, prediction of 2D saccade trajectories using our model could reduce the misalignment by 30% to 60% with the EyeLink tracker and 20% to 40% with the DPI tracker for saccades larger than 8°. Because a certain number of samples are required for model fitting, the prediction did not offer improvement for most small saccades and the early stages of large saccades. Evaluation was also performed for a simulated 100-Hz gaze-contingent display using the prerecorded saccade data. With prediction, the percentage of misalignment larger than 2° dropped from 45% to 20% for EyeLink and 42% to 26% for DPI data. These results suggest that the saccade-prediction algorithm may help create more accurate gaze-contingent displays. PMID:23902753

  11. Eye Globe Abnormalities on MR and CT in Adults: An Anatomical Approach.

    PubMed

    Hallinan, James Thomas Patrick Decourcy; Pillay, Premilla; Koh, Lilian Hui Li; Goh, Kong Yong; Yu, Wai-Yung

    2016-01-01

    Eye globe abnormalities can be readily detected on dedicated and non-dedicated CT and MR studies. A primary understanding of the globe anatomy is key to characterising both traumatic and non-traumatic globe abnormalities. The globe consists of three primary layers: the sclera (outer), uvea (middle), and retina (inner layer). The various pathological processes involving these layers are highlighted using case examples with fundoscopic correlation where appropriate. In the emergent setting, trauma can result in hemorrhage, retinal/choroidal detachment and globe rupture. Neoplasms and inflammatory/infective processes predominantly occur in the vascular middle layer. The radiologist has an important role in primary diagnosis contributing to appropriate ophthalmology referral, thereby preventing devastating consequences such as vision loss. PMID:27587955

  12. Eye Globe Abnormalities on MR and CT in Adults: An Anatomical Approach

    PubMed Central

    Pillay, Premilla; Koh, Lilian Hui Li; Goh, Kong Yong; Yu, Wai-Yung

    2016-01-01

    Eye globe abnormalities can be readily detected on dedicated and non-dedicated CT and MR studies. A primary understanding of the globe anatomy is key to characterising both traumatic and non-traumatic globe abnormalities. The globe consists of three primary layers: the sclera (outer), uvea (middle), and retina (inner layer). The various pathological processes involving these layers are highlighted using case examples with fundoscopic correlation where appropriate. In the emergent setting, trauma can result in hemorrhage, retinal/choroidal detachment and globe rupture. Neoplasms and inflammatory/infective processes predominantly occur in the vascular middle layer. The radiologist has an important role in primary diagnosis contributing to appropriate ophthalmology referral, thereby preventing devastating consequences such as vision loss. PMID:27587955

  13. Just a scary dream? A brief review of sleep terrors, nightmares, and rapid eye movement sleep behavior disorder.

    PubMed

    Haupt, Mark; Sheldon, Stephen H; Loghmanee, Darius

    2013-10-01

    The clinical spectrum of sleep disorders in children is broad, ranging from primary snoring and obstructive sleep apnea (OSA) syndrome to complex sleep-related behaviors and movement disorders. Although snoring and OSA typically receive significant attention and discussion, other biologically based sleep disorders are as common, if not more common, in children. A general pediatrician is frequently presented with the complaint of sleep talking, sleep walking, or abnormal movements during sleep. Even more alarming is the presentation of the child suddenly and explosively screaming during sleep. Such complaints fall under the category of parasomnias. Exclusive to sleep and wake-to-sleep transitions, these parasomnias include arousals with abnormal motor, behavioral, autonomic, or sensory symptoms. Parasomnias can be noticeably dissimilar in clinical manifestations, but most share biologic characteristics. Three parasomnias associated with loud vocalizations associated with sleep that can present to general practitioners include sleep terrors, nightmares, and rapid eye movement sleep behavior disorder (RBD). Although usually benign, these sleep disorders can be disruptive and even potentially dangerous to the patient and can often be threatening to quality of life. In this article, we describe the clinical features of some of these disorders and how to differentiate between their alarming presentations. PMID:24126984

  14. Human motion perception and smooth eye movements show similar directional biases for elongated apertures

    NASA Technical Reports Server (NTRS)

    Beutter, B. R.; Stone, L. S.

    1998-01-01

    Although numerous studies have examined the relationship between smooth-pursuit eye movements and motion perception, it remains unresolved whether a common motion-processing system subserves both perception and pursuit. To address this question, we simultaneously recorded perceptual direction judgments and the concomitant smooth eye-movement response to a plaid stimulus that we have previously shown generates systematic perceptual errors. We measured the perceptual direction biases psychophysically and the smooth eye-movement direction biases using two methods (standard averaging and oculometric analysis). We found that the perceptual and oculomotor biases were nearly identical, suggesting that pursuit and perception share a critical motion processing stage, perhaps in area MT or MST of extrastriate visual cortex.

  15. Human Motion Perception and Smooth Eye Movements Show Similar Directional Biases for Elongated Apertures

    NASA Technical Reports Server (NTRS)

    Beutter, Brent R.; Stone, Leland S.

    1997-01-01

    Although numerous studies have examined the relationship between smooth-pursuit eye movements and motion perception, it remains unresolved whether a common motion-processing system subserves both perception and pursuit. To address this question, we simultaneously recorded perceptual direction judgments and the concomitant smooth eye movement response to a plaid stimulus that we have previously shown generates systematic perceptual errors. We measured the perceptual direction biases psychophysically and the smooth eye-movement direction biases using two methods (standard averaging and oculometric analysis). We found that the perceptual and oculomotor biases were nearly identical suggesting that pursuit and perception share a critical motion processing stage, perhaps in area MT or MST of extrastriate visual cortex.

  16. The guidance of saccadic eye movements to perceptually mislocalized visual and non-visual targets

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Levine, M. S.

    1981-01-01

    The present experiment examined whether saccadic eye movements to visual targets are dependent on the perceived directions of the targets or on their retinally specified directions. Perceptual mislocations of visual targets were induced by having the target light attached to a subject's stationary hand while his biceps or triceps muscle was vibrated. Such vibration leads to apparent extension or flexion of the subject's restrained forearm and perceived visual motion of the stationary target light. Subjects always made accurate saccadic eye movements to a visual target, even when the target was perceptually mislocalized by as much as 20 deg. By contrast, when subjects made saccadic eye movements to a nonvisual target, the location of their hand in the dark, they always looked to the perceived direction of the target even though it did not necessarily correspond to the true direction. These findings indicate that a distinction is maintained between 'reflexive aspects' of oculomotor control related to foveation and the computation of perceived visual direction.

  17. Rapid eye movement-related brain activation in human sleep: a functional magnetic resonance imaging study.

    PubMed

    Wehrle, Renate; Czisch, Michael; Kaufmann, Christian; Wetter, Thomas C; Holsboer, Florian; Auer, Dorothee P; Pollmächer, Thomas

    2005-05-31

    In animal models, ponto-geniculo-occipital waves appear as an early sign of rapid eye movement sleep and may be functionally significant for brain plasticity processes. In this pilot study, we use a combined polysomnographic and functional magnetic resonance imaging approach, and show distinct magnetic resonance imaging signal increases in the posterior thalamus and occipital cortex in close temporal relationship to rapid eye movements during human rapid eye movement sleep. These findings are consistent with cell recordings in animal experiments and demonstrate that functional magnetic resonance imaging can be utilized to detect ponto-geniculo-occipital-like activity in humans. Studying intact neuronal networks underlying sleep regulation is no longer confined to animal models, but has been shown to be feasible in humans by a combined functional magnetic resonance imaging and electroencephalograph approach. PMID:15891584

  18. Looking without seeing or seeing without looking? Eye movements in sustained inattentional blindness.

    PubMed

    Beanland, Vanessa; Pammer, Kristen

    2010-05-12

    Inattentional blindness (IB) describes the failure to notice salient but unexpected stimuli when attention is partially engaged by another task. Few studies have explicitly investigated the role of eye movements in IB and the relative contributions of overt and covert attention. We recorded eye movements in a series of IB experiments using dynamic stimuli. Results indicate that eye movements do not predict IB; noticers and nonnoticers were equally likely to fixate on or near the unexpected item, often for similar durations. Perceptual load also determines whether observers will fixate the unexpected object. In a high perceptual load task, IB was high (81%) and most participants did not allocate overt attention to the unexpected object. Under lower perceptual load IB decreased to 54% and both noticers and nonnoticers fixated on the unexpected object. PMID:20206648

  19. Nomen est omen: Investigating the dominance of nouns in word comprehension with eye movement analyses.

    PubMed Central

    Furtner, Marco R.; Rauthmann, John F.; Sachse, Pierre

    2009-01-01

    Although nouns are easily learned in early stages of lexical development, their role in adult word and text comprehension remains unexplored thus far. To investigate the role of different word classes (open-class words: nouns, adjectives, verbs; closed-class words: pronouns, prepositions, conjunctions, etc.), 141 participants read a transposed German text while recording eye movements. Subsequently, participants indicated words they found difficult and reproduced the story. Then, participants were presented an untransposed text version while also tracking eye movements. Word difficulty, subjectively assessed by an interview and objectively by eye movement criteria (general fixation rate, number of fixations on specific words), text comprehension scores, and regressive fixations from one word class to another in the transposed text indicated that the noun was the most influential word class in enhancing the comprehension of other words. Developmental, intercultural, and neurophysiological aspects of noun dominance are discussed. PMID:20523853

  20. Impulse processing: A dynamical systems model of incremental eye movements in the visual world paradigm

    PubMed Central

    Kukona, Anuenue; Tabor, Whitney

    2011-01-01

    The visual world paradigm presents listeners with a challenging problem: they must integrate two disparate signals, the spoken language and the visual context, in support of action (e.g., complex movements of the eyes across a scene). We present Impulse Processing, a dynamical systems approach to incremental eye movements in the visual world that suggests a framework for integrating language, vision, and action generally. Our approach assumes that impulses driven by the language and the visual context impinge minutely on a dynamical landscape of attractors corresponding to the potential eye-movement behaviors of the system. We test three unique predictions of our approach in an empirical study in the visual world paradigm, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the visual world paradigm. PMID:21609355

  1. The effects of eye movement training on gait function in patients with stroke

    PubMed Central

    Kang, Kwon-Young; Yu, Kyung-Hoon

    2016-01-01

    [Purpose] The present study examined the effects of eye movement training on gait function in patients with stroke. [Subjects and Methods] Fourteen patients with stroke were randomly assigned to either an experimental group or a control group. The experimental group underwent eye movement training while the control group underwent general gait training five times per week for six weeks. [Results] Patient walking speed, cadence, and step length were measured by ink-footprint. The experimental group exhibited significant changes in walking speed, cadence, and step length following training, while the control group exhibited no differences. [Conclusion] Findings indicate that eye movement training should be considered as part of a functional gait training program for patients with stroke. PMID:27390423

  2. A Theory of Eye Movements during Target Acquisition

    ERIC Educational Resources Information Center

    Zelinsky, Gregory J.

    2008-01-01

    The gaze movements accompanying target localization were examined via human observers and a computational model (target acquisition model [TAM]). Search contexts ranged from fully realistic scenes to toys in a crib to Os and Qs, and manipulations included set size, target eccentricity, and target-distractor similarity. Observers and the model…

  3. Excessive twitch movements in rapid eye movement sleep with daytime sleepiness.

    PubMed

    Mizuma, H; Sakamoto, T

    1997-12-01

    A man who showed excessive twitch movement, such as fragmentary myoclonus (FM) and periodic movements in sleep (PMS) predominantly during REM sleep, is reported. He complained of excessive daytime sleepiness (EDS). After examination, his twitch movements were shown not to accompany narcolepsy, and his EDS were considered to originate from nocturnal sleep disturbance caused by FM and PMS. PMID:9472125

  4. Relationship between head orientation and torsional eye movements in goldfish during linear acceleration

    NASA Astrophysics Data System (ADS)

    Takabayashi, A.; Ohmura, T.; Mori, S.

    We analyzed torsional eye movements of normal goldfish during sinusoidal linear acceleration, altering the orientation of the fish on the linear accelerator in the yaw plane over a range of 90 degrees and in the pitch plane up to 30 degrees. We video-recorded changes of torsional eye movements associated with a body rotation in the yaw and pitch plane and analyzed them frame by frame. In normal fish, we observed clear torsional eye movements for stimuli of 0.1G linear accelerations along the body axis in the horizontal position. Torsion occurred in the opposite direction of resultant force produced by linear acceleration and gravity. Though the amplitude of these compensatory responses increased with increasing magnitude of acceleration up to 0.5 G, the torsion angle did not fully compensate the angle calculated from gravity and linear acceleration. Furthermore, the torsion angle decreased as the longitudinal body axis deviated from the direction of linear acceleration. For the body axis perpendicular to the direction of acceleration, torsional eye movement was still observed. When we tilted the fish in the pitch plane, compensatory eye torsion occurred. The response amplitude to acceleration decreased for both head-up and head-down up to 30 degrees. These results suggested the existence of specific connections between the otolith organ and ocular muscles.

  5. 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

  6. Analysis of substitution test performance using eye movement and video data.

    PubMed

    Stephens, Richard; Sreenivasan, Balraj

    2002-01-01

    Substitution tests continue to enjoy widespread popularity in applied neuropsychology. Though highly sensitive, these tests lack specificity, and substitution test decrements are often reported in terms that bear little relation to cognitive or other psychological theory. Objectives were to quantify, using eye movement/video analysis, subitem performance elements for the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol Test (DST); to assess the relative contribution of each of these to standard WAIS-R DST performance in a group; and to assess whether wearing the eye-movement measuring equipment interfered with test performance. PMID:12584083

  7. OCT corneal topography within ¼ diopter in the presence of saccadic eye movements

    NASA Astrophysics Data System (ADS)

    Sayegh, Samir I.

    2013-03-01

    Refractive surgeons and cataract surgeons need accurate measurements of corneal curvature/power. Increased expectations of patients, the increasing number of patients having undergone prior surgeries and patients with corneal pathologies dictate the need for reliable curvature measurements to enhance the predictability and the quality of surgical outcomes. Eye movements can negatively influence these measurements. We present a model of eye movements based on peak saccade velocities and formulate criteria for obtaining OCT topography within ¼ of a diopter. Using these criteria we illustrate how next generation MHz systems will allow full corneal OCT topography in both healthy and pathological corneas

  8. Direction of Perceived Motion and Eye Movements Show Similar Biases for Asymmetrically Windowed Moving Plaids

    NASA Technical Reports Server (NTRS)

    Beutter, B. R.; Mulligan, J. B.; Stone, L. S.; Hargens, Alan R. (Technical Monitor)

    1995-01-01

    We have shown that moving a plaid in an asymmetric window biases the perceived direction of motion (Beutter, Mulligan & Stone, ARVO 1994). We now explore whether these biased motion signals might also drive the smooth eye-movement response by comparing the perceived and tracked directions. The human smooth oculomotor response to moving plaids appears to be driven by the perceived rather than the veridical direction of motion. This suggests that human motion perception and smooth eye movements share underlying neural motion-processing substrates as has already been shown to be true for monkeys.

  9. Shifts of attention bias awareness of voluntary and reflexive eye movements.

    PubMed

    Robinson, Maria M; Irwin, David E

    2016-06-01

    Current theories regarding factors that influence people's awareness of their actions have underscored the role of peripheral signals (e.g., proprioceptive feedback) and central commands (e.g., the intention to make a response). The role of covert attention has been largely underexplored, even though attention and awareness have been tightly linked. The aim of the current study was to directly examine the impact of shifts of visual attention on people's awareness of their eye movements as they performed the antisaccade task. People tend to be unaware of a high percentage of erroneous eye movements on this task, thus lending it to the study of variables that might modulate people's awareness of their actions. In addition, this task provides the opportunity to compare two classes of actions, voluntary (antisaccade) and involuntary (erroneous prosaccade) eye movements, and thus to assess whether shifts of covert attention can or cannot override sources of information that may be present when people make voluntary but not reflexive responses. We found that shifts of visual attention did indeed influence participants' awareness of their own eye movements, leading them to misperceive reflexive and voluntary movements alike, suggesting that covert attention may override both peripheral and central signals to bias awareness. PMID:26873348

  10. ERPs and Eye Movements Reflect Atypical Visual Perception in Pervasive Developmental Disorder

    ERIC Educational Resources Information Center

    Kemner, Chantal; van Engeland, Herman

    2006-01-01

    Many studies of eye tracking or event-related brain potentials (ERPs) in subjects with Pervasive Developmental Disorder (PDD) have yielded inconsistent results on attentional processing. However, recent studies have indicated that there are specific abnormalities in early processing that are probably related to perception. ERP amplitudes in…

  11. An initial investigation of radiologist eye movements in vascular imaging

    NASA Astrophysics Data System (ADS)

    Toomey, R. J.; Hodgins, S.; Evanoff, M. E.; Rainford, L. A.

    2013-03-01

    Eye tracking has been used by many researchers to try to shed light on the perceptual processes involved in medical image perception. Despite a large volume of data having been published regarding radiologist viewing patterns for static images, and more recently for stacked imaging modalities, little has been produced concerning angiographic images, which commonly have substantially different characteristics. A study was performed in which 7 expert radiologists viewed a range of digital subtraction angiograms of the peripheral vascular system. Initial results are presented. The observers were free to control the rate at which they viewed the images. Eye position data was recorded for each participant using Tobii TX300 eyetrackers. Analysis was performed in Tobii Studio software and included qualitative analysis of gaze pattern and analysis of metrics including first and total fixation duration etc. for areas of clinical interest. Early results indicate that experts briefly fixate on lesions but do not dwell in the area, rather continuing to inspect the more distal vascular segments before returning. Some individual variation was noted. Further research is required and ongoing.

  12. Quantitative measurements of eye movements in a patient with Tullio phenomenon.

    PubMed

    Rottach, K G; von Maydell, R D; DiScenna, A O; Zivotofsky, A Z; Averbuch-Heller, L; Leigh, R J

    1996-01-01

    The Tullio phenomenon consists of vestibular symptoms on exposure to high-intensity acoustic stimuli, reflecting pathological stimulation of semicircular canals or otoliths. We report a patient with posttraumatic Tullio phenomenon to illustrate how precise measurement of eye movements during auditory stimulation, using the magnetic search coil technique, may characterize movements that are not clinically apparent or easily measured by other means. Such measurements in patients with surgically verified lesions may further elucidate the mechanisms responsible for this phenomenon. PMID:8839822

  13. The role of eye movements in the size-speed illusion of approaching trains.

    PubMed

    Clark, Helen E; Perrone, John A; Isler, Robert B; Charlton, Samuel G

    2016-01-01

    Recent research on the perceived speed of large moving objects, compared to smaller moving objects, has revealed the presence of a size-speed illusion. This illusion, where a large object seems to be moving more slowly than a small object travelling at the same speed may account for collisions between motor cars and trains at level crossings, which is a serious safety issue in New Zealand and worldwide. One possible reason for the perceived size-speed difference may be related to the movement of our eyes when we track moving vehicles. In order to investigate this, we tested observers' relative speed perception of moving objects (both abstract and more detailed objects) moving in depth towards the observer, presented on a computer display and eye movements recorded with an eyetracker. Experiment 1 confirmed first the size-speed illusion when the observers were situated further away (18, 36m) from the simulated rail crossing or intersection. It also revealed that the eye movement behaviour of our participants was different when they judged the speeds of the small and large objects; eye fixations were localised around the visual centroid of longer objects and hence were further from the front of the moving large objects than the smaller ones. Experiment 2 found that manipulating eye movements could reduce the magnitude of the illusion. When observers tracked targets (dots) that were placed at corresponding locations at the front of the small object and the long object respectively, they perceived the speeds of the two objects as equal. When target dots were placed closer to the visual centroid, observers perceived the larger object to be moving slower. These results demonstrate that there is a close relationship between eye movement behaviour and our perceived judgement of an approaching train's speed. PMID:26554596

  14. TorsinA hypofunction causes abnormal twisting movements and sensorimotor circuit neurodegeneration

    PubMed Central

    Liang, Chun-Chi; Tanabe, Lauren M.; Jou, Stephanie; Chi, Frank; Dauer, William T.

    2014-01-01

    Lack of a preclinical model of primary dystonia that exhibits dystonic-like twisting movements has stymied identification of the cellular and molecular underpinnings of the disease. The classical familial form of primary dystonia is caused by the DYT1 (ΔE) mutation in TOR1A, which encodes torsinA, AAA+ ATPase resident in the lumen of the endoplasmic reticular/nuclear envelope. Here, we found that conditional deletion of Tor1a in the CNS (nestin-Cre Tor1aflox/–) or isolated CNS expression of DYT1 mutant torsinA (nestin-Cre Tor1aflox/ΔE) causes striking abnormal twisting movements. These animals developed perinuclear accumulation of ubiquitin and the E3 ubiquitin ligase HRD1 in discrete sensorimotor regions, followed by neurodegeneration that was substantially milder in nestin-Cre Tor1aflox/ΔE compared with nestin-Cre Tor1aflox/– animals. Similar to the neurodevelopmental onset of DYT1 dystonia in humans, the behavioral and histopathological abnormalities emerged and became fixed during CNS maturation in the murine models. Our results establish a genetic model of primary dystonia that is overtly symptomatic, and link torsinA hypofunction to neurodegeneration and abnormal twisting movements. These findings provide a cellular and molecular framework for how impaired torsinA function selectively disrupts neural circuits and raise the possibility that discrete foci of neurodegeneration may contribute to the pathogenesis of DYT1 dystonia. PMID:24937429

  15. Anticipatory effects of intonation: Eye movements during instructed visual search.

    PubMed

    Ito, Kiwako; Speer, Shari R

    2008-02-01

    Three eye-tracking experiments investigated the role of pitch accents during online discourse comprehension. Participants faced a grid with ornaments, and followed pre-recorded instructions such as "Next, hang the blue ball" to decorate holiday trees. Experiment 1 demonstrated a processing advantage for felicitous as compared to infelicitous uses of L+H* on the adjective noun pair (e.g. blue ball followed by GREEN ball vs. green BALL). Experiment 2 confirmed that L+H* on a contrastive adjective led to 'anticipatory' fixations, and demonstrated a "garden path" effect for infelicitous L+H* in sequences with no discourse contrast (e.g. blue angel followed by GREEN ball resulted in erroneous fixations to the cell of angels). Experiment 3 examined listeners' sensitivity to coherence between pitch accents assigned to discourse markers such as 'And then,' and those assigned to the target object noun phrase. PMID:19190719

  16. Eye movements, the perceptual span, and reading speed

    PubMed Central

    Rayner, Keith; Slattery, Timothy J.; Bélanger, Nathalie N.

    2011-01-01

    The perceptual span or region of effective vision during eye fixations in reading was examined as a function of reading speed (fast readers were compared to slow readers), font characteristics (fixed width vs. proportional width), and intra-word spacing (normal or reduced). The main findings were that fast readers (reading at about 330 wpm) had a larger perceptual span than slow readers (reading about 200 wpm) and the span was not affected by whether or not the text was fixed-width or proportional-width. Additionally, there were interesting font and intra-word spacing effects that have important implications for the optimal use of space in a line of text. PMID:21169577

  17. Anticipatory effects of intonation: Eye movements during instructed visual search

    PubMed Central

    Ito, Kiwako; Speer, Shari R

    2007-01-01

    Three eye-tracking experiments investigated the role of pitch accents during online discourse comprehension. Participants faced a grid with ornaments, and followed pre-recorded instructions such as “Next, hang the blue ball” to decorate holiday trees. Experiment 1 demonstrated a processing advantage for felicitous as compared to infelicitous uses of L+H* on the adjective noun pair (e.g. blue ball followed by GREEN ball vs. green BALL). Experiment 2 confirmed that L+H* on a contrastive adjective led to ‘anticipatory’ fixations, and demonstrated a “garden path” effect for infelicitous L+H* in sequences with no discourse contrast (e.g. blue angel followed by GREEN ball resulted in erroneous fixations to the cell of angels). Experiment 3 examined listeners’ sensitivity to coherence between pitch accents assigned to discourse markers such as ‘And then,’ and those assigned to the target object noun phrase. PMID:19190719

  18. State reversals of optically induced tilt and torsional eye movements

    NASA Technical Reports Server (NTRS)

    Finke, R. A.; Held, R.

    1978-01-01

    Alternations of the state of apparent self-motion during observation of a large visual display rotating about the line of sight are associated with alternations in the magnitude of induced tilt and torsional eye rotation. In one experiment, shifts in visually induced tilt during these state alternations are found to be in the opposite direction to corresponding shifts in induced ocular torsion. In a second experiment, the reversals of self-motion perception are shown to be an intravisual phenomenon, independent of competing inputs provided by the vestibular system. These results emphasize the importance of distinguishing between visual and vestibular processes in tilt perception and ocular rotation during human orientation to gravitational vertical.

  19. Neuronal substrate and effective connectivity of abnormal movement sequencing in schizophrenia.

    PubMed

    Zemankova, Petra; Lungu, Ovidiu; Huttlova, Jitka; Kerkovsky, Milos; Zubor, Jozef; Lipova, Petra; Bares, Martin; Kasparek, Tomas

    2016-06-01

    Movement sequencing difficulties are part of the neurological soft signs (NSS), they have high clinical value because they are not always present in schizophrenia. We investigated the neuronal correlates of movement sequencing in 24 healthy controls and 24 schizophrenia patients, with (SZP SQ+) or without (SZP SQ-) sequencing difficulties. We characterized simultaneous and lagged functional connectivity between brain regions involved in movement sequencing using psychophysiological interaction (PPI) and the Granger causality modeling (GCM), respectively. Left premotor cortex (PMC) and superior parietal lobule (SPL) were specifically activated during sequential movements in all participants. Right PMC and precuneus, ipsilateral to the hand executing the task, activated during sequential movements only in healthy controls and SZP SQ-. SZP SQ+ showed hyperactivation in contralateral PMC, as compared to the other groups. PPI analysis revealed a deficit in inhibitory connections within this fronto-parietal network in SZP SQ+ during sequential task. GCM showed a significant lagged effective connectivity from right PMC to left SPL during task and rest periods in all groups and from right PMC to right precuneus in SZP SQ+ group only. Both SZP groups had a significant lagged connectivity from right to left PMC, during sequential task. Our results indicate that aberrant fronto-parietal network connectivity with cortical inhibition deficit and abnormal reliance on previous network activity are related to movement sequencing in SZP. The overactivation of motor cortex seems to be a good compensating strategy, the hyperactivation of parietal cortex is linked to motor deficit symptoms. PMID:26780603

  20. Information fusion control with time delay for smooth pursuit eye movement.

    PubMed

    Zhang, Menghua; Ma, Xin; Qin, Bin; Wang, Guangmao; Guo, Yanan; Xu, Zhigang; Wang, Yafang; Li, Yibin

    2016-05-01

    Smooth pursuit eye movement depends on prediction and learning, and is subject to time delays in the visual pathways. In this paper, an information fusion control method with time delay is presented, implementing smooth pursuit eye movement with prediction and learning as well as solving the problem of time delays in the visual pathways. By fusing the soft constraint information of the target trajectory of eyes and the ideal control strategy, and the hard constraint information of the eye system state equation and the output equation, optimal estimations of the co-state sequence and the control variable are obtained. The proposed control method can track not only constant velocity, sinusoidal target motion, but also arbitrary moving targets. Moreover, the absolute value of the retinal slip reaches steady state after 0.1 sec. Information fusion control method elegantly describes in a function manner how the brain may deal with arbitrary target velocities, how it implements the smooth pursuit eye movement with prediction, learning, and time delays. These two principles allowed us to accurately describe visually guided, predictive and learning smooth pursuit dynamics observed in a wide variety of tasks within a single theoretical framework. The tracking control performance of the proposed information fusion control with time delays is verified by numerical simulation results. PMID:27230904

  1. Hybrid EEG—Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal

    PubMed Central

    Mannan, Malik M. Naeem; Kim, Shinjung; Jeong, Myung Yung; Kamran, M. Ahmad

    2016-01-01

    Contamination of eye movement and blink artifacts in Electroencephalogram (EEG) recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI). In this paper, we proposed an automatic framework based on independent component analysis (ICA) and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data. PMID:26907276

  2. Hybrid EEG--Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal.

    PubMed

    Mannan, Malik M Naeem; Kim, Shinjung; Jeong, Myung Yung; Kamran, M Ahmad

    2016-01-01

    Contamination of eye movement and blink artifacts in Electroencephalogram (EEG) recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI). In this paper, we proposed an automatic framework based on independent component analysis (ICA) and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data. PMID:26907276

  3. Postsaccadic activities in the posterior parietal cortex of primates are influenced by both eye movement vectors and eye position.

    PubMed

    Genovesio, Aldo; Brunamonti, Emiliano; Giusti, Maria Assunta; Ferraina, Stefano

    2007-03-21

    Primates explore their visual environment by redirecting the gaze to objects of interest by alternating eye movements and periods of steady fixation. During this task, the fixation point changes frequently in depth. Therefore, the representation of object location based on retinal disparity requires frequent updating. Neural activity was recorded in the lateral intraparietal (LIP) area while monkeys performed saccades between targets in different depths. We report that in the early postsaccadic period, posterior parietal neurons continue to encode the difference in depth between fixation point and targets. About one-third of these neurons are, during the same period, modulated by eye position in depth as well. In the late postsaccadic period, the influence of the previous movement vector dissipates, and parietal neurons are modulated only by the new fixation distance. This result suggests that the postsaccadic activity of area LIP contributes to the dynamic representation of the visual space, and it is compatible with the presence of both a vector subtraction computation and eye-position-dependent gain fields. PMID:17376987

  4. Monitoring eye movement with a computer based Electro-oculogram (EOG).

    PubMed

    Dibble, Jamie M; Teters, Cherish K

    2004-01-01

    This project investigated ways to improve retinal laser surgery techniques. Currently, the surgery is manual and not very accurate because the eye has a tendency to move involuntarily and the laser can cause permanent damage to the patient if the eye moves out of range. Therefore, an Electro-oculogram (EOG) system was designed and tested capable of recording eye movement in both horizontal and vertical directions using the voltages produced by the eye for the purpose of feedback to the surgeon. The EOG system consisted of various filters and amplifiers to amplify the small signals created by the eye, which were obtained using surface electrodes placed around the eyes. An LED board was also designed for the subject to follow various LED lights with his/her eyes in all directions. A program was written with LabView software that was used to control the LED board as well as record and analyze the EOG signals. MatLab was used in correlation with LabView to perform additional filtering and to find the mean, root square mean, and standard deviation of the signal. This data was used to determine if a relationship exists between the direction of eye movement and the voltage produced by the eye. The EOG system and LED board operated as expected and the LabView program was capable of recording and analyzing the signals. The information gathered from this project could make retinal laser surgery more precise and safer by alleviating the potential for error and therefore unintentional damage to the patient. PMID:15134002

  5. Establishing Object Correspondence across Eye Movements: Flexible Use of Spatiotemporal and Surface Feature Information

    ERIC Educational Resources Information Center

    Richard, Ashleigh M.; Luck, Steven J.; Hollingworth, Andrew

    2008-01-01

    Visual input is frequently disrupted by eye movements, blinks, and occlusion. The visual system must be able to establish correspondence between objects visible before and after a disruption. Current theories hold that correspondence is established solely on the basis of spatiotemporal information, with no contribution from surface features. In…

  6. Relation between dream content and eye movements tested by lucid dreams.

    PubMed

    Tholey, P

    1983-06-01

    This experiment illustrates that systematic observations in lucid dreams can be used to test hypotheses concerning the relation between dream content and eye movements. The observations were carried out by 5 students who had learned to induce lucid dreams by using the reflection technique developed by the author. Several hypotheses concerning the relation in question could be rejected. PMID:6877973

  7. A model of eye movements and visual working memory during problem solving in geometry.

    PubMed

    Epelboim, J; Suppes, P

    2001-05-01

    The Oculomotor Geometry Reasoning Engine (OGRE) was proposed to model eye movements and visual working memory during problem solving in geometry. OGRE postulates that geometrical elements from diagrams are added to visual working memory when they are scanned. Newly-added elements overwrite elements already in memory. The model was applied to eye-movement patterns of three subjects: two geometry experts and one non-expert. Their eye movements and verbal protocols were recorded as they solved geometry problems posed with diagrams. Subjects used highly redundant eye-movement patterns with multiple rescans of the same geometrical elements. OGRE's model of visual memory provided a good fit for the distribution of times between rescans. The model was used to estimate the size of visual working memory used in geometry. The estimates varied as a function of both problems and subjects, with means and standard deviations for each subject being: 5.3+/-1.4, 4.0+/-0.9 and 4.7+/-1.6. PMID:11343722

  8. Can Short Duration Visual Cues Influence Students' Reasoning and Eye Movements in Physics Problems?

    ERIC Educational Resources Information Center

    Madsen, Adrian; Rouinfar, Amy; Larson, Adam M.; Loschky, Lester C.; Rebello, N. Sanjay

    2013-01-01

    We investigate the effects of visual cueing on students' eye movements and reasoning on introductory physics problems with diagrams. Participants in our study were randomly assigned to either the cued or noncued conditions, which differed by whether the participants saw conceptual physics problems overlaid with dynamic visual cues. Students…

  9. Eye Movements as a Function of Response Contingencies Measured by Blackout Technique.

    ERIC Educational Resources Information Center

    Doran, Judith; Holland, James G.

    The experiment reported was designed to determine whether programed material low in response contingency, and thus yielding a high blackout ratio, is read less thoroughly than programed material heavily response contingent and yielding a low blackout ratio. Eye movements were compared for two parallel forms of the same program, differing only in…

  10. Age Differences in Online Processing of Video: An Eye Movement Study

    ERIC Educational Resources Information Center

    Kirkorian, Heather L.; Anderson, Daniel R.; Keen, Rachel

    2012-01-01

    Eye movements were recorded while sixty-two 1-year-olds, 4-year-olds, and adults watched television. Of interest was the extent to which viewers looked at the same place at the same time as their peers because high similarity across viewers suggests systematic viewing driven by comprehension processes. Similarity of gaze location increased with…

  11. The Early Development of Sight-Reading Skills in Adulthood: A Study of Eye Movements

    ERIC Educational Resources Information Center

    Penttinen, Marjaana; Huovinen, Erkki

    2011-01-01

    In this study the effects of skill development on the eye movements of beginning adult sight-readers were examined, focusing on changes in the allocation of visual attention within metrical units as well as in the processing of larger melodic intervals. The participants were future elementary school teachers, taking part in a 9-month-long music…

  12. Attention to Irregular Verbs by Beginning Learners of German: An Eye-Movement Study

    ERIC Educational Resources Information Center

    Godfroid, Aline; Uggen, Maren S.

    2013-01-01

    This study focuses on beginning second language learners' attention to irregular verb morphology, an area of grammar that many adults find difficult to acquire (e.g., DeKeyser, 2005; Larsen-Freeman, 2010). We measured beginning learners' eye movements during sentence processing to investigate whether or not they actually attend to…

  13. Anomalies in Real and Counterfactual Worlds: An Eye-Movement Investigation

    ERIC Educational Resources Information Center

    Ferguson, Heather J.; Sanford, Anthony J.

    2008-01-01

    Counterfactual reasoning is valid reasoning arising from premises that are true in a hypothetical model, but false in actuality. Investigations of counterfactuals have concentrated on reasoning and production, but psycholinguistic research has been more limited. We report three eye-movement studies investigating the comprehension of counterfactual…

  14. Brief Report: Eye-Movement Patterns during an Embedded Figures Test in Children with ASD

    ERIC Educational Resources Information Center

    Keehn, Brandon; Brenner, Laurie A.; Ramos, Aurora I.; Lincoln, Alan J.; Marshall, Sandra P.; Muller, Ralph-Axel

    2009-01-01

    The present study examined fixation frequency and duration during an Embedded Figures Test (EFT) in an effort to better understand the attentional and perceptual processes by which individuals with autism spectrum disorder (ASD) achieve accelerated EFT performance. In particular, we aimed to elucidate differences in the patterns of eye-movement in…

  15. Cognitive perspective-taking during scene perception in autism spectrum disorder: evidence from eye movements.

    PubMed

    Au-Yeung, Sheena K; Kaakinen, Johanna K; Benson, Valerie

    2014-02-01

    The present study examined how eye movements during scene viewing are modulated by adopting psychological perspectives in both adults with autism spectrum disorders (ASD) and typically developing adults. In the current study, participants viewed house scenes with either non-perspective-taking (look for valuable items/features of the house that need fixing) or perspective-taking instructions (imagine that you are a burglar/repairman) while their eye movements were recorded. The eye movement measures revealed that for the "look for the valuable items" and burglar perspective task, the ASD group showed typical relevance effects (the preference to look at schema-relevant compared with schema-irrelevant targets) in their eye movements. However, we found subtle processing differences between the groups that were related to initial orienting to and processing of schema-relevant items for the "look for the features that need fixing" and the repairman perspective-taking task. There was an absence of a relevance effect for the ASD group for the repairman perspective and its non-perspective-taking equivalent instruction showing that the identification of items relevant to those schemas was more difficult for the ASD group. The present findings suggest that resolving ambiguity may be a defining feature of complex information processing deficits in ASD. PMID:24265216

  16. Instrumentation Considerations in Research Involving Eye-Movement Contingent Stimulus Control. Technical Report No. 305.

    ERIC Educational Resources Information Center

    McConkie, George W.; And Others

    In the study of perception during reading, the use of eye movement contingent control of the stimulus display has proved to be a useful research technique. With such a system, it is possible to experimentally manipulate, in real time, the characteristics of the stimulus display that is present on selected fixations as reading is in progress and to…

  17. The Processing of Compound Words in English: Effects of Word Length on Eye Movements during Reading

    ERIC Educational Resources Information Center

    Juhasz, Barbara J.

    2008-01-01

    Two experiments are reported which investigated morphological processing in English using bilexemic compound words. Long and short compound words were presented in neutral sentences and eye movements were recorded while participants read the sentences to investigate the time course of compound word recognition. In Experiment 1, the frequency of…

  18. Eye-Movement Analysis of Students' Active Examination Strategy and Its Transfer in Visuospatial Representations

    ERIC Educational Resources Information Center

    Kim, Kinam; Kim, Minsung; Shin, Jungyeop; Ryu, Jaemyong

    2015-01-01

    This article examined the role of task demand and its effects on transfer in geographic learning. Student performance was measured through eye-movement analysis in two related experiments. In Experiment 1, the participants were told that they would travel through an area depicted in photographs either driving an automobile or observing the…

  19. Eye Movement Research and the Interaction between Television and Child-Related Characteristics.

    ERIC Educational Resources Information Center

    Baron, Lois J.

    The relationship of eye movements while watching television to reading ability, cognitive style, and mode of presentation was studied using as subjects 85 third-grade children who had been classified as good or poor readers by scores on the Gates-MacGinitie Reading Test; their cognitive style was measured by the Children's Embedded Figures which…

  20. The effect of horizontal eye movements on free recall: a preregistered adversarial collaboration.

    PubMed

    Matzke, Dora; Nieuwenhuis, Sander; van Rijn, Hedderik; Slagter, Heleen A; van der Molen, Maurits W; Wagenmakers, Eric-Jan

    2015-02-01

    A growing body of research has suggested that horizontal saccadic eye movements facilitate the retrieval of episodic memories in free recall and recognition memory tasks. Nevertheless, a minority of studies have failed to replicate this effect. This article attempts to resolve the inconsistent results by introducing a novel variant of proponent-skeptic collaboration. The proposed approach combines the features of adversarial collaboration and purely confirmatory preregistered research. Prior to data collection, the adversaries reached consensus on an optimal research design, formulated their expectations, and agreed to submit the findings to an academic journal regardless of the outcome. To increase transparency and secure the purely confirmatory nature of the investigation, the 2 parties set up a publicly available adversarial collaboration agreement that detailed the proposed design and all foreseeable aspects of the data analysis. As anticipated by the skeptics, a series of Bayesian hypothesis tests indicated that horizontal eye movements did not improve free recall performance. The skeptics suggested that the nonreplication may partly reflect the use of suboptimal and questionable research practices in earlier eye movement studies. The proponents countered this suggestion and used a p curve analysis to argue that the effect of horizontal eye movements on explicit memory did not merely reflect selective reporting. PMID:25621378

  1. An Eye-Movement Analysis of Ambiguity Resolution: Beyond Meaning Access

    ERIC Educational Resources Information Center

    Binder, Katherine S.; Morris, Robin K.

    2011-01-01

    The research reported here addresses the status of the unselected meaning of a lexically ambiguous word in developing the larger meaning of the text by independently manipulating lexical and discourse-level variables in the text. In a series of 3 eye-movement experiments, participants read passages that contained 2 occurrences of an ambiguous…

  2. 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…

  3. Evidence of Anticipatory Eye Movements in the Spatial Hebb Repetition Effect: Insights for Modeling Sequence Learning

    ERIC Educational Resources Information Center

    Tremblay, Sebastien; Saint-Aubin, Jean

    2009-01-01

    In the present study, the authors offer a window onto the mechanisms that drive the Hebb repetition effect through the analysis of eye movement and recall performance. In a spatial serial recall task in which sequences of dots are to be remembered in order, when one particular series is repeated every 4 trials, memory performance markedly improves…

  4. 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…

  5. Children's Eye-Movements during Reading Reflect the Quality of Lexical Representations: An Individual Differences Approach

    ERIC Educational Resources Information Center

    Luke, Steven G.; Henderson, John M.; Ferreira, Fernanda

    2015-01-01

    The lexical quality hypothesis (Perfetti & Hart, 2002) suggests that skilled reading requires high-quality lexical representations. In children, these representations are still developing, and it has been suggested that this development leads to more adult-like eye-movement behavior during the reading of connected text. To test this idea, a…

  6. Eye Movement Behaviour during Reading of Japanese Sentences: Effects of Word Length and Visual Complexity

    ERIC Educational Resources Information Center

    White, Sarah J.; Hirotani, Masako; Liversedge, Simon P.

    2012-01-01

    Two experiments are presented that examine how the visual characteristics of Japanese words influence eye movement behaviour during reading. In Experiment 1, reading behaviour was compared for words comprising either one or two kanji characters. The one-character words were significantly less likely to be fixated on first-pass, and had…

  7. An Eye Movement Analysis of the Spatial Contiguity Effect in Multimedia Learning

    ERIC Educational Resources Information Center

    Johnson, Cheryl I.; Mayer, Richard E.

    2012-01-01

    In three studies, eye movements of participants were recorded while they viewed a single-slide multimedia presentation about how car brakes work. Some of the participants saw an integrated presentation in which each segment of words was presented near its corresponding area of the diagram (integrated group, Experiments 1 and 3) or an integrated…

  8. 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…

  9. Vocabulary Acquisition without Adult Explanations in Repeated Shared Book Reading: An Eye Movement Study

    ERIC Educational Resources Information Center

    Evans, Mary Ann; Saint-Aubin, Jean

    2013-01-01

    When preschoolers listen to storybooks, are their eye movements related to their vocabulary acquisition in this context? This study addressed this question with 36 four-year-old French-speaking participants by assessing their general receptive vocabulary knowledge and knowledge of low-frequency words in 3 storybooks. These books were read verbatim…

  10. Using Eye Movements to Investigate Word Frequency Effects in Children's Sentence Reading

    ERIC Educational Resources Information Center

    Joseph, Holly S. S. L.; Nation, Kate; Liversedge, Simon P.

    2013-01-01

    skilled adult readers process written language, relatively little research has used this methodology with children. This is unfortunate as, as we discuss here, eye-movement studies have significant potential to inform our understanding of children's reading development. We…

  11. Eye Movements of University Students with and without Reading Difficulties during Naming Speed Tasks

    ERIC Educational Resources Information Center

    Al Dahhan, Noor; Georgiou, George K.; Hung, Rickie; Munoz, Douglas; Parrila, Rauno; Kirby, John R.

    2014-01-01

    Although naming speed (NS) has been shown to predict reading into adulthood and differentiate between adult dyslexics and controls, the question remains why NS is related to reading. To address this question, eye movement methodology was combined with three letter NS tasks (the original letter NS task by Denckla & Rudel, "Cortex"…

  12. Eye Movement Control in Scene Viewing and Reading: Evidence from the Stimulus Onset Delay Paradigm

    ERIC Educational Resources Information Center

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

    2013-01-01

    The present study used the stimulus onset delay paradigm to investigate eye movement control in reading and in scene viewing in a within-participants design. Short onset delays (0, 25, 50, 200, and 350 ms) were chosen to simulate the type of natural processing difficulty encountered in reading and scene viewing. Fixation duration increased…

  13. Individual Differences in the Processing of Written Sarcasm and Metaphor: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Olkoniemi, Henri; Ranta, Henri; Kaakinen, Johanna K.

    2016-01-01

    The present study examined individual differences in the processing of different forms of figurative language. Sixty participants read sarcastic, metaphorical, and literal sentences embedded in story contexts while their eye movements were recorded, and responded to a text memory and an inference question after each story. Individual differences…

  14. An Analysis of Eye Movement and Cognitive Load about the Editorial Design in Elementary Science Textbook

    ERIC Educational Resources Information Center

    Kim, Seong-un; Lim, Sung-man; Kim, Eun-ae; Yang, Il-ho

    2016-01-01

    This study is for the implication of editorial design in science textbooks which are designed for student-centered instruction, when the elements of the editorial design are different, we focus on how the students' eye movement and cognitive load change. For this, we produced a new book for 5th grade students in elementary school that is modified…

  15. Word Misperception, the Neighbor Frequency Effect, and the Role of Sentence Context: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Slattery, Timothy J.

    2009-01-01

    An eye movement experiment was conducted to investigate whether the processing of a word can be affected by its higher frequency neighbor (HFN). Target words with an HFN (birch) or without one (spruce) were embedded into 2 types of sentence frames: 1 in which the HFN (birth) could fit given the prior sentence context, and 1 in which it could not.…

  16. Additive Effects of Stimulus Quality and Word Frequency on Eye Movements during Chinese Reading

    ERIC Educational Resources Information Center

    Liu, Pingping; Li, Xingshan; Han, Buxin

    2015-01-01

    Eye movements of Chinese readers were recorded for sentences in which high- and low-frequency target words were presented normally or with reduced stimulus quality in two experiments. We found stimulus quality and word frequency produced strong additive effects on fixation durations for target words. The results demonstrate that stimulus quality…

  17. Effects of Saccadic Bilateral Eye Movements on Memory in Children and Adults: An Exploratory Study

    ERIC Educational Resources Information Center

    Parker, Andrew; Dagnall, Neil

    2012-01-01

    The effects of saccadic bilateral (horizontal) eye movements on true and false memory in adults and children were investigated. Both adults and children encoded lists of associated words in the Deese-Roediger-McDermott paradigm followed by a test of recognition memory. Just prior to retrieval, participants were asked to engage in 30 s of bilateral…

  18. Cognitive Load for Configuration Comprehension in Computer-Supported Geometry Problem Solving: An Eye Movement Perspective

    ERIC Educational Resources Information Center

    Lin, John Jr-Hung; Lin, Sunny S. J.

    2014-01-01

    The present study investigated (a) whether the perceived cognitive load was different when geometry problems with various levels of configuration comprehension were solved and (b) whether eye movements in comprehending geometry problems showed sources of cognitive loads. In the first investigation, three characteristics of geometry configurations…

  19. Plausibility Effects when Reading One- and Two-Character Words in Chinese: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Yang, Jinmian; Staub, Adrian; Li, Nan; Wang, Suiping; Rayner, Keith

    2012-01-01

    Eye movements of Chinese readers were monitored as they read sentences containing a critical character that was either a 1-character word or the initial character of a 2-character word. Due to manipulation of the verb prior to the target word, the 1-character target word (or the first character of the 2-character target word) was either plausible…

  20. "What Are You Looking At?" An Eye Movement Exploration in Science Text Reading

    ERIC Educational Resources Information Center

    Hung, Yueh-Nu

    2014-01-01

    The main purpose of this research was to investigate how Taiwanese grade 6 readers selected and used information from different print (main text, headings, captions) and visual elements (decorational, representational, interpretational) to comprehend a science text through tracking their eye movement behaviors. Six grade 6 students read a double…

  1. Target Selection by the Frontal Cortex during Coordinated Saccadic and Smooth Pursuit Eye Movements

    ERIC Educational Resources Information Center

    Srihasam, Krishna; Bullock, Daniel; Grossberg, Stephen

    2009-01-01

    Oculomotor tracking of moving objects is an important component of visually based cognition and planning. Such tracking is achieved by a combination of saccades and smooth-pursuit eye movements. In particular, the saccadic and smooth-pursuit systems interact to often choose the same target, and to maximize its visibility through time. How do…

  2. Perception of Object-Context Relations: Eye-Movement Analyses in Infants and Adults

    ERIC Educational Resources Information Center

    Bornstein, Marc H.; Mash, Clay; Arterberry, Martha E.

    2011-01-01

    Twenty-eight 4-month-olds' and twenty-two 20-year-olds' attention to object-context relations was investigated using a common eye-movement paradigm. Infants and adults scanned both objects and contexts. Infants showed equivalent preferences for animals and vehicles and for congruent and incongruent object-context relations overall, more fixations…

  3. Disturbances of saccadic eye movements in monkeys during development of MPTP-induced syndrome.

    PubMed

    Tereshchenko, L V; Yudin, A G; Kuznetsov, YuB; Latanov, A V; Shul'govskii, V V

    2002-02-01

    Changes in the amplitude and dynamic parameters of purposive saccades were studied in monkeys with MPTP-induced Parkinson-like syndrome. Lengthening of saccade latency, decreased maximum velocity of eye movements, and impaired saccade accuracy were observed at the early stages MPTP-syndrome. Different disturbances of large- and small-scale saccades were found. PMID:12428290

  4. Does Visual Attention Span Relate to Eye Movements during Reading and Copying?

    ERIC Educational Resources Information Center

    Bosse, Marie-Line; Kandel, Sonia; Prado, Chloé; Valdois, Sylviane

    2014-01-01

    This research investigated whether text reading and copying involve visual attention-processing skills. Children in grades 3 and 5 read and copied the same text. We measured eye movements while reading and the number of gaze lifts (GL) during copying. The children were also administered letter report tasks that constitute an estimation of the…

  5. Effects of individual differences in verbal skills on eye-movement patterns during sentence reading

    PubMed Central

    Kuperman, Victor; Van Dyke, Julie A.

    2011-01-01

    This study is a large-scale exploration of the influence that individual reading skills exert on eye-movement behavior in sentence reading. Seventy one non-college-bound 16–24 year-old speakers of English completed a battery of 18 verbal and cognitive skill assessments, and read a series of sentences as their eye movements were monitored. Statistical analyses were performed to establish what tests of reading abilities were predictive of eye-movement patterns across this population and how strong the effects were. We found that individual scores in rapid automatized naming and word identification tests (i) were the only participant variables with reliable predictivity throughout the time-course of reading; (ii) elicited effects that superceded in magnitude the effects of established predictors like word length or frequency; and (iii) strongly modulated the influence of word length and frequency on fixation times. We discuss implications of our findings for testing reading ability, as well as for research of eye-movements in reading. PMID:21709808

  6. Attending to Eye Movements and Retinal Eccentricity: Evidence for the Activity Distribution Model of Attention Reconsidered

    ERIC Educational Resources Information Center

    Turk-Browne, Nicholas B.; Pratt, Jay

    2005-01-01

    When testing between spotlight and activity distribution models of visual attention, D. LaBerge, R. L. Carlson, J. K. Williams, and B. G. Bunney (1997) used an experimental paradigm in which targets are embedded in 3 brief displays. This paradigm, however, may be confounded by retinal eccentricity effects and saccadic eye movements. When the…

  7. Dynamic Characteristics of Saccadic Eye Movements in Normal and Mentally Retarded Children.

    ERIC Educational Resources Information Center

    Takahashi, Teruko; And Others

    1987-01-01

    Analysis of saccadic eye movements in 10 normal and 10 mentally retarded children (ages 13-15) suggested that retarded children may have difficulty in visual orientation. They followed a visual target on fewer than 50 percent of the trials, displaying frequent undershoot patterns and an average rising latency that was much longer than that of…

  8. Interaction between Visual- and Goal-Related Neuronal Signals on the Trajectories of Saccadic Eye Movements

    ERIC Educational Resources Information Center

    White, Brian J.; Theeuwes, Jan; Munoz, Douglas P.

    2012-01-01

    During natural viewing, the trajectories of saccadic eye movements often deviate dramatically from a straight-line path between objects. In human studies, saccades have been shown to deviate toward or away from salient visual distractors depending on visual- and goal-related parameters, but the neurophysiological basis for this is not well…

  9. Eye Movements Reveal Students' Strategies in Simple Equation Solving

    ERIC Educational Resources Information Center

    Susac, Ana; Bubic, Andreja; Kaponja, Jurica; Planinic, Maja; Palmovic, Marijan

    2014-01-01

    Equation rearrangement is an important skill required for problem solving in mathematics and science. Eye movements of 40 university students were recorded while they were rearranging simple algebraic equations. The participants also reported on their strategies during equation solving in a separate questionnaire. The analysis of the behavioral…

  10. Masking produces compression of space and time in the absence of eye movements

    PubMed Central

    Born, Sabine; Fink, Gereon R.; Cavanagh, Patrick

    2014-01-01

    Whenever the visual stream is abruptly disturbed by eye movements, blinks, masks, or flashes of light, the visual system needs to retrieve the new locations of current targets and to reconstruct the timing of events to straddle the interruption. This process may introduce position and timing errors. We here report that very similar errors are seen in human subjects across three different paradigms when disturbances are caused by either eye movements, as is well known, or, as we now show, masking. We suggest that the characteristic effects of eye movements on position and time, spatial and temporal compression and saccadic suppression of displacement, are consequences of the interruption and the subsequent reconnection and are seen also when visual input is masked without any eye movements. Our data show that compression and suppression effects are not solely a product of ocular motor activity but instead can be properties of a correspondence process that links the targets of interest across interruptions in visual input, no matter what their source. PMID:25231617

  11. Language-Mediated Eye Movements in the Absence of a Visual World: The "Blank Screen Paradigm"

    ERIC Educational Resources Information Center

    Altmann, Gerry T. M.

    2004-01-01

    The "visual world paradigm" typically involves presenting participants with a visual scene and recording eye movements as they either hear an instruction to manipulate objects in the scene or as they listen to a description of what may happen to those objects. In this study, participants heard each target sentence only after the corresponding…

  12. Real-Time Control of a Video Game Using Eye Movements and Two Temporal EEG Sensors.

    PubMed

    Belkacem, Abdelkader Nasreddine; Saetia, Supat; Zintus-art, Kalanyu; Shin, Duk; Kambara, Hiroyuki; Yoshimura, Natsue; Berrached, Nasreddine; Koike, Yasuharu

    2015-01-01

    EEG-controlled gaming applications range widely from strictly medical to completely nonmedical applications. Games can provide not only entertainment but also strong motivation for practicing, thereby achieving better control with rehabilitation system. In this paper we present real-time control of video game with eye movements for asynchronous and noninvasive communication system using two temporal EEG sensors. We used wavelets to detect the instance of eye movement and time-series characteristics to distinguish between six classes of eye movement. A control interface was developed to test the proposed algorithm in real-time experiments with opened and closed eyes. Using visual feedback, a mean classification accuracy of 77.3% was obtained for control with six commands. And a mean classification accuracy of 80.2% was obtained using auditory feedback for control with five commands. The algorithm was then applied for controlling direction and speed of character movement in two-dimensional video game. Results showed that the proposed algorithm had an efficient response speed and timing with a bit rate of 30 bits/min, demonstrating its efficacy and robustness in real-time control. PMID:26690500

  13. How Readers Spontaneously Interpret "Man"-Suffix Words: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Khan, Manizeh; Daneman, Meredyth

    2011-01-01

    This study investigated whether readers are more likely to assign a male referent to man-suffix terms (e.g. "chairman") than to gender-neutral alternatives (e.g., "chairperson") during reading, and whether this bias differs as a function of age. Younger and older adults' eye movements were monitored while reading passages containing phrases such…

  14. Using Stroke Removal to Investigate Chinese Character Identification during Reading: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Yan, Guoli; Bai, Xuejun; Zang, Chuanli; Bian, Qian; Cui, Lei; Qi, Wei; Rayner, Keith; Liversedge, Simon P.

    2012-01-01

    We explored the effect of stroke removal from Chinese characters on eye movements during reading to examine the role of stroke encoding in character identification. Experimental sentences were comprised of characters with different proportions of strokes removed (15, 30, and 50%), and different types of strokes removed (beginning, ending, and…

  15. Eye movement desensitization treatment of a child's nightmares: a case report.

    PubMed

    Pellicer, X

    1993-03-01

    A new therapeutic method (eye movement desensitization), described in 1989 by Shapiro, was applied to the treatment of recurrent nightmares in a 10-year-old girl. The technique, in a single session, resulted in the complete remission of the nightmares. There was no relapse during a 6 month follow-up. PMID:8103777

  16. Like a rolling stone: naturalistic visual kinematics facilitate tracking eye movements.

    PubMed

    Souto, David; Kerzel, Dirk

    2013-01-01

    Newtonian physics constrains object kinematics in the real world. We asked whether eye movements towards tracked objects depend on their compliance with those constraints. In particular, the force of gravity constrains round objects to roll on the ground with a particular rotational and translational motion. We measured tracking eye movements towards rolling objects. We found that objects with rotational and translational motion that was congruent with an object rolling on the ground elicited faster tracking eye movements during pursuit initiation than incongruent stimuli. Relative to a condition without rotational component, we compared objects with this motion with a condition in which there was no rotational component, we essentially obtained benefits of congruence, and, to a lesser extent, costs from incongruence. Anticipatory pursuit responses showed no congruence effect, suggesting that the effect is based on visually-driven predictions, not on velocity storage. We suggest that the eye movement system incorporates information about object kinematics acquired by a lifetime of experience with visual stimuli obeying the laws of Newtonian physics. PMID:23390323

  17. Adult Dyslexic Readers Do Not Demonstrate Regularity Effects in Sentence Processing: Evidence from Eye-Movements

    ERIC Educational Resources Information Center

    Jones, Manon Wyn; Kelly, M. Louise; Corley, Martin

    2007-01-01

    We report an eye-movement study that demonstrates differences in regularity effects between adult developmental dyslexic and control non-impaired readers, in contrast to findings from a large number of word recognition studies (see G. Brown, 1997). For low frequency words, controls showed an advantage for Regular items, in which…

  18. Eye-Movement Patterns of Readers with Down Syndrome during Sentence-Processing: An Exploratory Study

    ERIC Educational Resources Information Center

    Frenck-Mestre, Cheryl; Zardan, Nathalie; Colas, Annie; Ghio, Alain

    2010-01-01

    Eye movements were examined to determine how readers with Down syndrome process sentences online. Participants were 9 individuals with Down syndrome ranging in reading level from Grades 1 to 3 and a reading-level-matched control group. For syntactically simple sentences, the pattern of reading times was similar for the two groups, with longer…

  19. Eye movements while reading an unspaced writing system: the case of Thai.

    PubMed

    Kasisopa, Benjawan; G Reilly, Ronan; Luksaneeyanawin, Sudaporn; Burnham, Denis

    2013-06-28

    Thai has an alphabetic script with a distinctive feature - it has no spaces between words. Since previous research with spaced alphabetic systems (e.g., English) has suggested that readers use spaces to guide eye movements, it is of interest to investigate what physical factors might guide Thai readers' eye movements. Here the effects of word-initial and word-final position-specific character frequency, word-boundary bigram frequency, and overall word frequency on 30 Thai adults' eye movements when reading unspaced and spaced text was investigated. Linear mixed-effects model analyses of viewing time measures (first fixation duration, single fixation duration, and gaze duration) and of landing sites were conducted. Thai readers tended to land their first fixation at or near the centre of words, just as readers of spaced texts do. A critical determinant of this was word boundary characters: higher position-specific frequency of initial and of final characters significantly facilitated landing sites closer to the word centre while word-boundary bigram frequency appeared to behave as a proxy for initial and final position-specific character frequency. It appears, therefore, that Thai readers make use of the position-specific frequencies of word boundary characters in targeting words and directing eye movements to an optimal landing site. PMID:23608059

  20. Punctuation and Intonation Effects on Clause and Sentence Wrap-Up: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Hirotani, Masako; Frazier, Lyn; Rayner, Keith

    2006-01-01

    Three eye movement studies examined the role of punctuation in reading. In Experiment 1, although a comma at the end of a clause facilitated overall reading times for the sentence, first pass times were longer at the end of comma-marked clauses than clauses without a comma (or the same material in clause medial position). The data supported the…

  1. Letter Names and Alphabet Book Reading by Senior Kindergarteners: An Eye Movement Study

    ERIC Educational Resources Information Center

    Evans, Mary Ann; Saint-Aubin, Jean; Landry, Nadine

    2009-01-01

    The study monitored the eye movements of twenty 5-year-old children while reading an alphabet book to examine the manner in which the letters, words, and pictures were fixated and the relation of attention to print to alphabetic knowledge. Children attended little to the print, took longer to first fixate print than illustrations, and labeled…

  2. Eye Movement Control during Reading: Effects of Word Frequency and Orthographic Familiarity

    ERIC Educational Resources Information Center

    White, Sarah J.

    2008-01-01

    Word frequency and orthographic familiarity were independently manipulated as readers' eye movements were recorded. Word frequency influenced fixation durations and the probability of word skipping when orthographic familiarity was controlled. These results indicate that lexical processing of words can influence saccade programming (as shown by…

  3. Using Reinforcement Learning to Understand the Emergence of "Intelligent" Eye-Movement Behavior during Reading

    ERIC Educational Resources Information Center

    Reichle, Erik D.; Laurent, Patryk A.

    2006-01-01

    The eye movements of skilled readers are typically very regular (K. Rayner, 1998). This regularity may arise as a result of the perceptual, cognitive, and motor limitations of the reader (e.g., limited visual acuity) and the inherent constraints of the task (e.g., identifying the words in their correct order). To examine this hypothesis,…

  4. Children's Processing of Reflexives and Pronouns in English: Evidence from Eye-Movements during Listening

    ERIC Educational Resources Information Center

    Clackson, Kaili; Felser, Claudia; Clahsen, Harald

    2011-01-01

    This study examined how 6-9 year-old English-speaking children and adults establish anaphoric dependencies during auditory sentence comprehension. Using eye-movement monitoring during listening and a corresponding sentence-picture judgment task, we investigated both the ultimate interpretation and the online processing of reflexives in comparison…

  5. Orthography and the Development of Reading Processes: An Eye-Movement Study of Chinese and English

    ERIC Educational Resources Information Center

    Feng, Gary; Miller, Kevin; Shu, Hua; Zhang, Houcan

    2009-01-01

    As children become proficient readers, there are substantial changes in the eye movements that subserve reading. Some of these changes reflect universal developmental factors while others may be specific to a particular writing system. This study attempts to disentangle effects of universal and script-dependent factors by comparing the development…

  6. Effects of Contextual Predictability and Transitional Probability on Eye Movements During Reading

    ERIC Educational Resources Information Center

    Frisson, Steven; Rayner, Keith; Pickering, Martin J.

    2005-01-01

    In 2 eye-movement experiments, the authors tested whether transitional probability (the statistical likelihood that a word precedes or follows another word) affects reading times and whether this occurs independently from contextual predictability effects. Experiment 1 showed early effects of predictability, replicating S. A. McDonald and R. C.…

  7. Immediacy of Integration in Discourse Comprehension: Evidence from Chinese Readers' Eye Movements

    ERIC Educational Resources Information Center

    Wang, Suiping; Chen, Hsuan-Chih; Yang, Jinmian; Mo, Lei

    2008-01-01

    An eye-movement study was conducted to examine whether Chinese readers immediately activate and integrate related background information during discourse comprehension. Participants were asked to read short passages, each containing a critical word that fitted well within the local context but was inconsistent or neutral with background…

  8. A Review of Eye Movement Desensitization and Reprocessing (EMDR): Research Findings and Implications for Counsellors.

    ERIC Educational Resources Information Center

    MacCluskie, Kathryn C.

    1998-01-01

    States that within the last six years a new therapeutic technique for the treatment of posttraumatic stress disorder, Eye Movement Desensitization and Reprocessing (EMDR), has emerged. Examines the strengths and weaknesses of published studies concerning EMDR, describes the nature of the debate about the efficacy of EMDR, and reviews implications…

  9. Using Eye Movement Desensitization and Reprocessing To Enhance Treatment of Couples.

    ERIC Educational Resources Information Center

    Protinsky, Howard; Sparks, Jennifer; Flemke, Kimberly

    2001-01-01

    Eye Movement Desensitization and Reprocessing (EMDR) as a clinical technique may enhance treatment effectiveness when applied in couple therapy that is emotionally and experientially oriented. Clinical experience indicates EMDR-based interventions are useful for accessing and reprocessing intense emotions in couple interactions. EMDR can amplify…

  10. Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

    ERIC Educational Resources Information Center

    Wilson, Sandra A.; And Others

    1995-01-01

    Studies the effects of 3 90-minute Eye Movement Desensitization and Reprocessing (EMDR) treatment sessions on traumatic memories of 80 participants. Participants receiving EMDR showed decreases in complaints and anxiety, and increases in positive cognition. Participants in the delayed-treatment condition showed no improvement in any measures in…

  11. 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…

  12. Toward an Appropriate Baseline for Measures of Eye Movement Behavior During Reading

    ERIC Educational Resources Information Center

    McDonald, Scott A.; Shillcock, Richard C.

    2005-01-01

    In empirical studies of human eye movement behavior during reading, it is common to compute various summary measures from the data, but these measures are typically not evaluated with respect to corresponding measures of baseline performance. The authors present a method for deriving an appropriate baseline by mapping the actual behavior to a…

  13. Complement Coercion Is Not Modulated by Competition: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Frisson, Steven; McElree, Brian

    2008-01-01

    An eye-movement study examined the processing of expressions requiring complement coercion (J. Pustejovsky, 1995), in which a noun phrase that does not denote an event (e.g., the book) appears as the complement of an event-selecting verb (e.g., began the book). Previous studies demonstrated that these expressions are more costly to process …

  14. Real-Time Control of a Video Game Using Eye Movements and Two Temporal EEG Sensors

    PubMed Central

    Saetia, Supat; Zintus-art, Kalanyu; Shin, Duk; Kambara, Hiroyuki; Yoshimura, Natsue; Berrached, Nasreddine; Koike, Yasuharu

    2015-01-01

    EEG-controlled gaming applications range widely from strictly medical to completely nonmedical applications. Games can provide not only entertainment but also strong motivation for practicing, thereby achieving better control with rehabilitation system. In this paper we present real-time control of video game with eye movements for asynchronous and noninvasive communication system using two temporal EEG sensors. We used wavelets to detect the instance of eye movement and time-series characteristics to distinguish between six classes of eye movement. A control interface was developed to test the proposed algorithm in real-time experiments with opened and closed eyes. Using visual feedback, a mean classification accuracy of 77.3% was obtained for control with six commands. And a mean classification accuracy of 80.2% was obtained using auditory feedback for control with five commands. The algorithm was then applied for controlling direction and speed of character movement in two-dimensional video game. Results showed that the proposed algorithm had an efficient response speed and timing with a bit rate of 30 bits/min, demonstrating its efficacy and robustness in real-time control. PMID:26690500

  15. Coregistration of Eye Movements and EEG in Natural Reading: Analyses and Review

    ERIC Educational Resources Information Center

    Dimigen, Olaf; Sommer, Werner; Hohlfeld, Annette; Jacobs, Arthur M.; Kliegl, Reinhold

    2011-01-01

    Brain-electric correlates of reading have traditionally been studied with word-by-word presentation, a condition that eliminates important aspects of the normal reading process and precludes direct comparisons between neural activity and oculomotor behavior. In the present study, we investigated effects of word predictability on eye movements (EM)…

  16. Effects of Handedness and Saccadic Bilateral Eye Movements on Components of Autobiographical Recollection

    ERIC Educational Resources Information Center

    Parker, Andrew; Dagnall, Neil

    2010-01-01

    The effects of handedness and saccadic bilateral eye movements on autobiographical recollection were investigated. Recall of autobiographical memories was cued by the use of neutral and emotional words. Autobiographical recollection was assessed by the autobiographical memory questionnaire. Experiment 1 found that mixed-handed (vs. right handed)…

  17. EyeSeeCam: an eye movement-driven head camera for the examination of natural visual exploration.

    PubMed

    Schneider, Erich; Villgrattner, Thomas; Vockeroth, Johannes; Bartl, Klaus; Kohlbecher, Stefan; Bardins, Stanislavs; Ulbrich, Heinz; Brandt, Thomas

    2009-05-01

    The prototype of a gaze-controlled, head-mounted camera (EyeSeeCam) was developed that provides the functionality for fundamental studies on human gaze behavior even under dynamic conditions like locomotion. EyeSeeCam incorporates active visual exploration by saccades with image stabilization during head, object, and surround motion just as occurs in human ocular motor control. This prototype is a first attempt to combine free user mobility with image stabilization and unrestricted exploration of the visual surround in a man-made technical vision system. The gaze-driven camera is supplemented by an additional wide-angle, head-fixed scene camera. In this scene view, the focused gaze view is embedded with picture-in-picture functionality, which provides an approximation of the foveated retinal content. Such a combined video clip can be viewed more comfortably than the saccade-pervaded image of the gaze camera alone. EyeSeeCam consists of a video-oculography (VOG) device and a camera motion device. The benchmark for the evaluation of such a device is the vestibulo-ocular reflex (VOR), which requires a latency on the order of 10 msec between head and eye (camera) movements for proper image stabilization. A new lightweight VOG was developed that is able to synchronously measure binocular eye positions at up to 600 Hz. The camera motion device consists of a parallel kinematics setup with a backlash-free gimbal joint that is driven by piezo actuators with no reduction gears. As a result, the latency between the rotations of an artificial eye and the camera was 10 msec, which is VOR-like. PMID:19645949

  18. Williams syndrome and its cognitive profile: the importance of eye movements

    PubMed Central

    Van Herwegen, Jo

    2015-01-01

    People with Williams syndrome (WS), a rare neurodevelopmental disorder that is caused by a deletion on the long arm of chromosome 7, often show an uneven cognitive profile with participants performing better on language and face recognition tasks, in contrast to visuospatial and number tasks. Recent studies have shown that this specific cognitive profile in WS is a result of atypical developmental processes that interact with and affect brain development from infancy onward. Using examples from language, face processing, number, and visuospatial studies, this review evaluates current evidence from eye-tracking and developmental studies and argues that domain general processes, such as the ability to plan or execute saccades, influence the development of these domain-specific outcomes. Although more research on eye movements in WS is required, the importance of eye movements for cognitive development suggests a possible intervention pathway to improve cognitive abilities in this population. PMID:26082669

  19. Neuronal Representation of 3-D Space in the Primary Visual Cortex and Control of Eye Movements.

    PubMed

    Alekseenko, Svetlana V

    2015-01-01

    The aim of this article is to consider the correlations between the structure of the primary visual cortical area V1 and control of coordinated movements of the two eyes. Using the anatomical data available, a schematic map of 3-D space representation in the layer IV of area V1 containing only monocular cells has been constructed. The analysis of this map revealed that binocular neurons of V1, which are formed by convergence of monocular cells, should encode the absolute disparity. Participation of monocular and binocular neurons of V1 in the control of convergence, divergence, and version eye movements is discussed. It is proposed that synchronous contraction of corresponding extraocular muscles of both eyes for vergence might be ensured by duplicated transmission of information from the central part of retina to visual cortex of both hemispheres. PMID:26562914

  20. 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.

  1. Quantitative evaluation of a low-cost noninvasive hybrid interface based on EEG and eye movement.

    PubMed

    Kim, Minho; Kim, Byung Hyung; Jo, Sungho

    2015-03-01

    This paper describes a low-cost noninvasive brain-computer interface (BCI) hybridized with eye tracking. It also discusses its feasibility through a Fitts' law-based quantitative evaluation method. Noninvasive BCI has recently received a lot of attention. To bring the BCI applications into real life, user-friendly and easily portable devices need to be provided. In this work, as an approach to realize a real-world BCI, electroencephalograph (EEG)-based BCI combined with eye tracking is investigated. The two interfaces can be complementary to attain improved performance. Especially to consider public availability, a low-cost interface device is intentionally used for test. A low-cost commercial EEG recording device is integrated with an inexpensive custom-built eye tracker. The developed hybrid interface is evaluated through target pointing and selection experiments. Eye movement is interpreted as cursor movement and noninvasive BCI selects a cursor point with two selection confirmation schemes. Using Fitts' law, the proposed interface scheme is compared with other interface schemes such as mouse, eye tracking with dwell time, and eye tracking with keyboard. In addition, the proposed hybrid BCI system is discussed with respect to a practical interface scheme. Although further advancement is required, the proposed hybrid BCI system has the potential to be practically useful in a natural and intuitive manner. PMID:25376041

  2. Looking to Understand: The Coupling between Speakers' and Listeners' Eye Movements and Its Relationship to Discourse Comprehension

    ERIC Educational Resources Information Center

    Richardson, Daniel C.; Dale, Rick

    2005-01-01

    We investigated the coupling between a speaker's and a listener's eye movements. Some participants talked extemporaneously about a television show whose cast members they were viewing on a screen in front of them. Later, other participants listened to these monologues while viewing the same screen. Eye movements were recorded for all speakers and…

  3. 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,…

  4. 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 visualizing it from…

  5. Hawk Eyes II: Diurnal Raptors Differ in Head Movement Strategies When Scanning from Perches

    PubMed Central

    O'Rourke, Colleen T.; Pitlik, Todd; Hoover, Melissa; Fernández-Juricic, Esteban

    2010-01-01

    Background Relatively little is known about the degree of inter-specific variability in visual scanning strategies in species with laterally placed eyes (e.g., birds). This is relevant because many species detect prey while perching; therefore, head movement behavior may be an indicator of prey detection rate, a central parameter in foraging models. We studied head movement strategies in three diurnal raptors belonging to the Accipitridae and Falconidae families. Methodology/Principal Findings We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species. Conclusions Cooper's Hawks, Red-tailed Hawks, and American Kestrels use both regular and translational head movements, but to different extents. We conclude that these diurnal raptors have species-specific strategies to gather visual information while perching. These strategies may optimize prey search and detection with different visual systems in habitat types with different degrees of visual obstruction. PMID:20877650

  6. Inferences about predictable events: eye movements during reading.

    PubMed

    Calvo, M G; Meseguer, E; Carreiras, M

    2001-01-01

    Eye fixations were recorded to assess whether, how, and when readers draw inferences about predictable events. Predicting context sentences, or non-predicting control sentences, were presented, followed by continuation sentences in which a target word referred to a predictable event (inferential word) or an unlikely event (non-predictable word). There were no effects on initial target word processing measures, such as launch and landing sites, fixation probability, first-fixation duration, or first-pass reading time. However, relative to the control condition, the predicting context (1) speeded up reanalysis of the inferential word, as revealed by a reduction in second-pass reading time and regressions, and (2) interfered with processing of the non-predictable word, as shown by an increase in regressions. These results indicate that predictive inferences are active at late text integration processes, rather than at early lexical-access processes. The pattern of findings suggests that these inferences involve initial activation of rather general concepts following the inducing context, and that they are completed or refined with delay, after the inferential target word is read. PMID:11571911

  7. Eye movements reveal fast, voice-specific priming.

    PubMed

    Papesh, Megan H; Goldinger, Stephen D; Hout, Michael C

    2016-03-01

    In spoken word perception, voice specificity effects are well-documented: When people hear repeated words in some task, performance is generally better when repeated items are presented in their originally heard voices, relative to changed voices. A key theoretical question about voice specificity effects concerns their time-course: Some studies suggest that episodic traces exert their influence late in lexical processing (the time-course hypothesis; McLennan & Luce, 2005), whereas others suggest that episodic traces influence immediate, online processing. We report 2 eye-tracking studies investigating the time-course of voice-specific priming within and across cognitive tasks. In Experiment 1, participants performed modified lexical decision or semantic classification to words spoken by 4 speakers. The tasks required participants to click a red "x" or a blue "+" located randomly within separate visual half-fields, necessitating trial-by-trial visual search with consistent half-field response mapping. After a break, participants completed a second block with new and repeated items, half spoken in changed voices. Voice effects were robust very early, appearing in saccade initiation times. Experiment 2 replicated this pattern while changing tasks across blocks, ruling out a response priming account. In the General Discussion, we address the time-course hypothesis, focusing on the challenge it presents for empirical disconfirmation, and highlighting the broad importance of indexical effects, beyond studies of priming. PMID:26726911

  8. The processing of metonymy: evidence from eye movements.

    PubMed

    Frisson, S; Pickering, M J

    1999-11-01

    The authors investigated the time course of the processing of metonymic expressions in comparison with literal ones in 2 eye-tracking experiments. Experiment 1 considered the processing of sentences containing place-for-institution metonymies such as the convent in That blasphemous woman had to answer to the convent; it was found that such expressions were of similar difficulty to sentences containing literal interpretations of the same expressions. In contrast, expressions without a relevant metonymic interpretation caused immediate difficulty. Experiment 2 found similar results for place-for-event metonymies such as A lot of Americans protested during Vietnam, except that the difficulty with expressions without a relevant metonymic interpretation was somewhat delayed. The authors argue that these findings are incompatible with models of figurative language processing in which either the literal sense is accessed first or the figurative sense is accessed first. Instead, they support an account in which both senses can be accessed immediately, perhaps through a single under-specified representation. PMID:10605827

  9. Eye Movements Reveal Fast, Voice-Specific Priming

    PubMed Central

    Papesh, Megan H.; Goldinger, Stephen D.; Hout, Michael C.

    2015-01-01

    In spoken word perception, voice specificity effects are well-documented: When people hear repeated words in some task, performance is generally better when repeated items are presented in their originally heard voices, relative to changed voices. A key theoretical question about voice specificity effects concerns their time-course: Some studies suggest that episodic traces exert their influence late in lexical processing (the time-course hypothesis; McLennan & Luce, 2005), whereas others suggest that episodic traces influence immediate, online processing. We report two eye-tracking studies investigating the time-course of voice-specific priming within and across cognitive tasks. In Experiment 1, participants performed modified lexical decision or semantic classification to words spoken by four speakers. The tasks required participants to click a red “×” or a blue “+” located randomly within separate visual half-fields, necessitating trial-by-trial visual search with consistent half-field response mapping. After a break, participants completed a second block with new and repeated items, half spoken in changed voices. Voice effects were robust very early, appearing in saccade initiation times. Experiment 2 replicated this pattern while changing tasks across blocks, ruling out a response priming account. In the General Discussion, we address the time-course hypothesis, focusing on the challenge it presents for empirical disconfirmation, and highlighting the broad importance of indexical effects, beyond studies of priming. PMID:26726911

  10. Movement-related cortical potentials in paraplegic patients: abnormal patterns and considerations for BCI-rehabilitation

    PubMed Central

    Xu, Ren; Jiang, Ning; Vuckovic, Aleksandra; Hasan, Muhammad; Mrachacz-Kersting, Natalie; Allan, David; Fraser, Matthew; Nasseroleslami, Bahman; Conway, Bernie; Dremstrup, Kim; Farina, Dario

    2014-01-01

    Non-invasive EEG-based Brain-Computer Interfaces (BCI) can be promising for the motor neuro-rehabilitation of paraplegic patients. However, this shall require detailed knowledge of the abnormalities in the EEG signatures of paraplegic patients. The association of abnormalities in different subgroups of patients and their relation to the sensorimotor integration are relevant for the design, implementation and use of BCI systems in patient populations. This study explores the patterns of abnormalities of movement related cortical potentials (MRCP) during motor imagery tasks of feet and right hand in patients with paraplegia (including the subgroups with/without central neuropathic pain (CNP) and complete/incomplete injury patients) and the level of distinctiveness of abnormalities in these groups using pattern classification. The most notable observed abnormalities were the amplified execution negativity and its slower rebound in the patient group. The potential underlying mechanisms behind these changes and other minor dissimilarities in patients’ subgroups, as well as the relevance to BCI applications, are discussed. The findings are of interest from a neurological perspective as well as for BCI-assisted neuro-rehabilitation and therapy. PMID:25221505

  11. Three dimensional kinematics of rapid compensatory eye movements in humans with unilateral vestibular deafferentation.

    PubMed

    Tian, Jun-Ru; Crane, Benjamin T; Ishiyama, Akira; Demer, Joseph L

    2007-09-01

    Saccades executed with the head stationary have kinematics conforming to Listing's law (LL), confining the ocular rotational axis to Listing's plane (LP). In unilateral vestibular deafferentation (UVD), the vestibulo-ocular reflex (VOR), which does not obey LL, has at high head acceleration a slow phase that has severely reduced velocity during ipsilesional rotation, and mildly reduced velocity during contralesional rotation. Studying four subjects with chronic UVD using 3D magnetic search coils, we investigated kinematics of stereotypic rapid eye movements that supplement the impaired VOR. We defined LP with the head immobile, and expressed eye and head movements as quaternions in LP coordinates. Subjects underwent transient whole body yaw at peak acceleration 2,800 degrees /s(2) while fixating targets centered, or 20 degrees up or down prior to rotation. The VOR shifted ocular torsion out of LP. Vestibular catch-up saccades (VCUS) occurred with mean latency 90 +/- 44 ms (SD) from ipsilesional rotation onset, maintained initial non-LL torsion so that their quaternion trajectories paralleled LP, and had velocity axes changing by half of eye position. During contralesional rotation, rapid eye movements occurred at mean latency 135 +/- 36 ms that were associated with abrupt decelerations (ADs) of the horizontal slow phase correcting 3D deviations in its velocity axis, with quaternion trajectories not paralleling LP. Rapid eye movements compensating for UVD have two distinct kinematics. VCUS have velocity axis dependence on eye position consistent with LL, so are probably programmed in 2D by neural circuits subserving visual saccades. ADs have kinematics that neither conform to LL nor match the VOR axis, but appear instead programmed in 3D to correct VOR axis errors. PMID:17549461

  12. Eye-movement training-induced plasticity in patients with post-stroke hemianopia.

    PubMed

    Nelles, Gereon; Pscherer, Anja; de Greiff, Armin; Forsting, Michael; Gerhard, Horst; Esser, Joachim; Diener, H Christoph

    2009-05-01

    Substantial disability in patients with hemianopia results from reduced visual perception. Previous studies have shown that these patients have impaired saccades. Improving exploratory eye movements with appropriate training of saccades may help to partially compensate for the visuoperceptive impairment during daily life activities. The changes in cortical control of eye movements that may be induced by these training strategies, however, are not known. We used functional magnetic resonance imaging (fMRI) to study the training effects of eye-movement training on cortical control of saccades. Brain activation during visually guided saccades was measured in eight patients with an occipital cortical lesion causing homonymous hemianopia. Starting 8 weeks after the stroke, patients received 4 weeks of visual field training. The fMRI measurements were performed at baseline and after training. In five patients, follow-up fMRI was performed 4 weeks after the end of training. Differences in activation between rest and saccades as well as before and after training were assessed with statistical parametric mapping software (SPM'99). Twelve healthy subjects were scanned twice at a 4-week interval. In patients, significant activation at baseline was found in the frontal and parietal eye fields (FEF and PEF, respectively) bilaterally and in the supplementary eye field (SEF). Immediately after training, an area of increased activation was found in the left extrastriate cortex of the affected hemisphere. At follow-up, relatively more activation was found in the right peristriate cortex and in the SEF of the unaffected side. A relative decrease of activation was found in the left FEF. In this group of patients, eye-movement training induced altered brain activation in the striate and extrastriate cortex as well as in oculomotor areas. PMID:19240963

  13. Properties of cerebellar fastigial neurons during translation, rotation, and eye movements

    NASA Technical Reports Server (NTRS)

    Shaikh, Aasef G.; Ghasia, Fatema F.; Dickman, J. David; Angelaki, Dora E.

    2005-01-01

    The most medial of the deep cerebellar nuclei, the fastigial nucleus (FN), receives sensory vestibular information and direct inhibition from the cerebellar vermis. We investigated the signal processing in the primate FN by recording single-unit activities during translational motion, rotational motion, and eye movements. Firing rate modulation during horizontal plane translation in the absence of eye movements was observed in all non-eye-movement-sensitive cells and 26% of the pursuit eye-movement-sensitive neurons in the caudal FN. Many non-eye-movement-sensitive cells recorded in the rostral FN of three fascicularis monkeys exhibited convergence of signals from both the otolith organs and the semicircular canals. At low frequencies of translation, the majority of these rostral FN cells changed their firing rates in phase with head velocity rather than linear acceleration. As frequency increased, FN vestibular neurons exhibited a wide range of response dynamics with most cells being characterized by increasing phase leads as a function of frequency. Unlike cells in the vestibular nuclei, none of the rostral FN cells responded to rotational motion alone, without simultaneously exhibiting sensitivity to translational motion. Modulation during earth-horizontal axis rotation was observed in more than half (77%) of the neurons, although with smaller gains than during translation. In contrast, only 47% of the cells changed their firing rates during earth-vertical axis rotations in the absence of a dynamic linear acceleration stimulus. These response properties suggest that the rostral FN represents a main processing center of otolith-driven information for inertial motion detection and spatial orientation.

  14. Eye Movements and the Neural Basis of Context Effects on Visual Sensitivity

    PubMed Central

    Ennis, Robert; Cao, Dingcai; Lee, Barry B.

    2014-01-01

    The effects of context on visual sensitivity are well established (e.g., sensitivity to luminance flicker is substantially higher on mean-gray surrounds than on white or black surrounds). The neural mechanisms generating context effects, however, remain unresolved. In the absence of direct tests, some theories invoke enhancement of edges by lateral inhibition, whereas others rely on transients caused by miniature eye movements that maintain fixation. We first replicated the luminance results on human observers and found unexpectedly that sensitivity to red-green flicker is also affected by surround color, being substantially higher on mean-gray surrounds than on red or green surrounds. To identify the neural bases of both context effects, we used in vivo electrophysiological recordings of primate magnocellular and parvocellular ganglion cell responses to luminance and red-green modulations, respectively. To test neuronal sensitivity to stationary edge contrast, neuronal responses were measured at various distances from the modulation edge against various surrounds. We found no evidence of enhanced responses to stationary edges on any surrounds, ruling out lateral inhibition-type explanations. To simulate the effects of eye movements, target patches were abruptly displaced while measuring responses. Abruptly displaced edges evoked vigorous transient responses that were selective for modulation-phase on mean-gray surrounds, but were phase-invariant on other surrounds. Eye movements could thus enhance detection of flicker on mean-gray surrounds, and neurometric analyses supported a primary role for eye movements in enhancing sensitivity. In addition, the transformation of spatial edges to transient neuronal responses by eye movements provides the signals for detecting luminance and color edges in natural scenes. PMID:24920617

  15. 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. PMID:24467663

  16. Eye and head movements during vestibular stimulation in the alert rabbit.

    PubMed

    Fuller, J H

    1981-02-01

    Rabbits passively oscillated in the horizontal plane with a free hand tended to stabilize their head in space (re: earth-fixed surroundings) by moving the head on the trunk (neck angular deviation, NAD) opposite the passively imposed body rotation. The gain (NAD/body rotation) of head stabilization varied from 0.0 to 0.95 (nearly perfect stability) and was most commonly above 0.5. Horizontal eye movement (HEM) was inversely proportional to head-in-space stability, i.e. the gaze (sum of HEM, NAD, and body rotation) was stable in space (regardless of the gain of head stabilization). When the head was fixed to the rotating platform, attempted head movements (head torque) mimicked eye movements in both the slow and fast phases of vestibular nystagmus; tonic eye position was also accompanied by conjugate shifts in tonic head torque. Thus, while eye and head movements may at times be linked, that the slow eye and head movements vary inversely during vestibular stimulation with a free head indicates that the linkage is not rigid. Absence of a textured stationary visual field consistently produced a response termed 'visual inattentiveness,' which was characterized by, among other things, a reduction of head and gaze stability in space. This behavioral response could also be reproduced in a subject allowed vision during prolonged vestibular stimulation in the absence of other environmental stimuli. It is suggested that rabbits optimize gaze stability (re: stationary surroundings), with the head contributing variably, as long as the animal is attending to its surroundings. PMID:7470870

  17. Characteristic visuomotor influences on eye-movement patterns to faces and other high level stimuli

    PubMed Central

    Arizpe, Joseph M.; Walsh, Vincent; Baker, Chris I.

    2015-01-01

    Eye-movement patterns are often utilized in studies of visual perception as indices of the specific information extracted to efficiently process a given stimulus during a given task. Our prior work, however, revealed that not only the stimulus and task influence eye-movements, but that visuomotor (start position) factors also robustly and characteristically influence eye-movement patterns to faces (Arizpe et al., 2012). Here we manipulated lateral starting side and distance from the midline of face and line-symmetrical control (butterfly) stimuli in order to further investigate the nature and generality of such visuomotor influences. First we found that increasing starting distance from midline (4°, 8°, 12°, and 16° visual angle) strongly and proportionately increased the distance of the first ordinal fixation from midline. We did not find influences of starting distance on subsequent fixations, however, suggesting that eye-movement plans are not strongly affected by starting distance following an initial orienting fixation. Further, we replicated our prior effect of starting side (left, right) to induce a spatially contralateral tendency of fixations after the first ordinal fixation. However, we also established that these visuomotor influences did not depend upon the predictability of the location of the upcoming stimulus, and were present not only for face stimuli but also for our control stimulus category (butterflies). We found a correspondence in overall left-lateralized fixation tendency between faces and butterflies. Finally, for faces, we found a relationship between left starting side (right sided fixation pattern tendency) and increased recognition performance, which likely reflects a cortical right hemisphere (left visual hemifield) advantage for face perception. These results further indicate the importance of considering and controlling for visuomotor influences in the design, analysis, and interpretation of eye-movement studies. PMID:26283982

  18. 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.

  19. Rapid eye movements to a virtual target are biased by illusory context in the Poggendorff figure.

    PubMed

    Melmoth, D; Grant, S; Solomon, J A; Morgan, M J

    2015-07-01

    In order to determine the influence of perceptual input upon oculomotor responses, we examined rapid saccadic eye movements made by healthy human observers to a virtual target defined by the extrapolated intersection of a pointer with a distant landing line. While corresponding perceptual judgments showed no evidence of systematic bias, eye movements showed a strong bias, in the direction of assimilation of the saccade trajectory to the shortest path between the end of the pointer and the landing line. Adding an abutting vertical inducing line to make an angle of 45 deg with the pointer led to a larger bias in the same direction as the classical Poggendorff illusion. This additional Poggendorff effect was similar in direction and magnitude for the eye movements and the perceptual responses. Latency and dynamics of the eye movements were closely similar to those recorded for a control task in which observers made a saccade from the start fixation to an explicit target on the landing line. Further experiments with inducing lines presented briefly at various times during the saccade latency period showed that the magnitude of the saccade bias was affected by inducer presentation during the saccade planning process, but not during the saccade itself. We conclude that the neural mechanisms for extrapolation can feed into the control of eye movements without obvious penalties in timing and accuracy and that this information can instantaneously modify motor response throughout the planning phase, suggesting close association between perceptual and motor mechanisms in the process of visuo-spatial extrapolation. PMID:25912606

  20. 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