WorldWideScience

Sample records for eye movement measures

  1. Measuring miniature eye movements by means of a SQUID magnetometer

    NARCIS (Netherlands)

    Peters, M.J.; Dunajski, Z.; Meijzssen, T.E.M.; Breukink, E.W.; Wevers-Henke, J.J.

    1982-01-01

    A new technique to measure small eye movements is reported. The precise recording of human eye movements is necessary for research on visual fatigue induced by visual display units.1 So far all methods used have disadvantages: especially those which are sensitive or are rather painful.2,3 Our method

  2. Measuring miniature eye movements by means of a SQUID magnetometer

    NARCIS (Netherlands)

    Peters, M.J.; Dunajski, Z.; Meijzssen, T.E.M.; Breukink, E.W.; Wevers-Henke, J.J.

    1982-01-01

    A new technique to measure small eye movements is reported. The precise recording of human eye movements is necessary for research on visual fatigue induced by visual display units.1 So far all methods used have disadvantages: especially those which are sensitive or are rather painful.2,3 Our method

  3. Eye Movement Disorders

    Science.gov (United States)

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

  4. The eye movement measure of memory and its relationship with explicit measures.

    Science.gov (United States)

    Chen, Hsiang-Chun; Lee, Yuh-shiow

    2015-05-01

    This study examined whether the eye movement can be used to measure memory of past events and its relationship with the explicit measures. In Experiment 1, after studying a list of Chinese characters, the participants received a recognition memory test. For each trial the participants had to indicate, among one studied character and two nonstudied homonyms, which character they had studied. Participants' eye movements were monitored while they viewed the three-character test display. Both the time-course and response-locked measures showed that participants viewed the studied character longer than the nonstudied character regardless of their explicit response. Experiment 2 used a wagering task to assess participants' conscious awareness and found that wagering points predicted viewing time for the target better than the recognition accuracy did. These findings suggest that the effect of memory on viewing time occurs automatically and is weakly associated with subsequent conscious awareness of the studied event. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Capturing learning effects on eye movements in repeated measures experiments

    DEFF Research Database (Denmark)

    Bagger, Martin; Orquin, Jacob Lund; Fiedler, Susann

    We propose and illustrate that repeated exposure to stimuli sets increases the size of the saccade amplitudes. Saccadic amplitudes are closely related to the perceptual span and therefore used as a measure for the information intake in an experiment. Studies on expertise have shown that experts...... experiment in which 68 participants made choices between four alternatives with three different between subject conditions varying in presentation format (verbal matrix, a pictorial matrix, and a realistic product representation). The results consistently demonstrate an increase of the saccade amplitude over...... the course of the experiment independent of condition. We conclude by discussing our results in the light of the possible increase of the perceptual span and its implications for the research procedure in eye-tracking experiments with a repeated measurement design....

  6. A Model-Based Approach for the Measurement of Eye Movements Using Image Processing

    Science.gov (United States)

    Sung, Kwangjae; Reschke, Millard F.

    1997-01-01

    This paper describes a video eye-tracking algorithm which searches for the best fit of the pupil modeled as a circular disk. The algorithm is robust to common image artifacts such as the droopy eyelids and light reflections while maintaining the measurement resolution available by the centroid algorithm. The presented algorithm is used to derive the pupil size and center coordinates, and can be combined with iris-tracking techniques to measure ocular torsion. A comparison search method of pupil candidates using pixel coordinate reference lookup tables optimizes the processing requirements for a least square fit of the circular disk model. This paper includes quantitative analyses and simulation results for the resolution and the robustness of the algorithm. The algorithm presented in this paper provides a platform for a noninvasive, multidimensional eye measurement system which can be used for clinical and research applications requiring the precise recording of eye movements in three-dimensional space.

  7. The effects of eye movements on emotional memories: using an objective measure of cognitive load

    Science.gov (United States)

    van Veen, Suzanne C.; Engelhard, Iris M.; van den Hout, Marcel A.

    2016-01-01

    Background Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. The working memory (WM) theory explains its efficacy: recall of an aversive memory and making eye movements (EM) both produce cognitive load, and competition for the limited WM resources reduces the memory's vividness and emotionality. The present study tested several predictions from WM theory. Objective We hypothesized that 1) recall of an aversive autobiographical memory loads WM compared to no recall, and 2) recall with EM reduces the vividness, emotionality, and cognitive load of recalling the memory more than only recall or only cognitive effort (i.e., recall of an irrelevant memory with EM). Method Undergraduates (N=108) were randomly assigned to one of three conditions: 1) recall relevant memory with EM, 2) recall relevant memory without EM, and 3) recall irrelevant memory with EM. We used a random interval repetition task to measure the cognitive load of recalling the memory. Participants responded to randomly administered beeps, with or without recalling the memory. The degree to which participants slow down during recall provides an index of cognitive load. We measured the cognitive load and self-reported vividness and emotionality before, halfway through (8×24 s), and after (16×24 s) the intervention. Results Reaction times slowed down during memory recall compared to no recall. The recall relevant with EM condition showed a larger decrease in self-reported vividness and emotionality than the control conditions. The cognitive load of recalling the memory also decreased in this condition but not consistently more than in the control conditions. Conclusions Recall of an aversive memory loads WM, but drops in vividness and emotionality do not immediately reduce the cognitive load of recalling the memory. More research is needed to find objective measures that could capture changes in the quality of the memory. Highlights of the

  8. Measuring cognitive processes involved in the web search: log files, eye-movements and cued rertospective reports

    NARCIS (Netherlands)

    Argelagos, Esther; Jarodzka, Halszka; Pifarre, Manoli

    2011-01-01

    Argelagós, E., Jarodzka, H., & Pifarré, M. (2011, August). Measuring cognitive processes involved in web search: log files, eye-movements and cued retrospective reports compared. Presentation at EARLI, Exeter, UK.

  9. The use of chromatic information for motion segmentation: differences between psychophysical and eye-movement measures.

    Science.gov (United States)

    Dobkins, Karen R; Sampath, Vanitha

    2008-01-01

    Previous psychophysical studies have shown that chromatic (red/green) information can be used as a segmentation cue for motion integration. We investigated the mechanisms mediating this phenomenon by comparing chromatic effects (and, for comparison, luminance effects) on motion integration between two measures: (i) directional eye movements with the notion that these responses are mediated mainly by low-level motion mechanisms, and (ii) psychophysical reports, with the notion that subjects' reports should employ higher-level (attention-based) mechanisms if available. To quantify chromatic (and luminance) effects on motion integration, coherent motion thresholds were obtained for two conditions, one in which the signal and noise dots were the same 'red' or 'green' chromaticity (or the same 'bright' or 'dark' luminance), referred to as homogeneous, and the other in which the signal and noise dots were of different chromaticities (or luminances), referred to as heterogeneous. 'Benefit ratios' (theta(HOM)/theta(HET)) were then computed, with values significantly greater than 1.0 indicating that chromatic (or luminance) information serves as a segmentation cue for motion integration. The results revealed a high and significant chromatic benefit ratio when the measure was based on psychophysical report, but not when it was based on an eye-movement measure. By contrast, luminance benefit ratios were roughly the same (and significant) for both measures. For comparison to adults, eye-movement data were also obtained from 3-month-old infants. Infants showed marginally significant benefit ratios in the luminance, but not in the chromatic, condition. In total, these results suggest that the use of chromatic information as a segmentation cue for motion integration relies on higher-level mechanisms, whereas luminance information works mainly through low-level motion mechanisms.

  10. The relationship between children‘s reading ability, verbal and fluid intelligence and measurements of eye movements during reading

    Directory of Open Access Journals (Sweden)

    Orlovska M.

    2014-01-01

    Full Text Available The aim of this study was to clarify, which of the following two measures: verbal intelligence or measurements of eye movements, is better predictor of reading ability. In addition, the study also investigated the relationships between reading ability, fluid intelligence and measurements of eye movements. Participants of the study (N = 28; mean age = 8.80; SD = .41; 54% boys were assessed in reading with LMST-I Reading achievement test, verbal and fluid intelligence was measured using two scales – Verbal Comprehension and Perceptual reasoning – from Latvian edition of Wechsler Intelligence Scale for Children Fourth Edition (WISC- IV, Latvian version, as well as eye tracking was made during reading. The results show that reading ability is better predicted by fixation duration and fixation count measurements of eye movements for 8-9 old children, whereas verbal ability in general does not predict reading ability. The better link with level of reading is provided by measurements of eye movements, but not so accurately reflected by verbal ability in appropriate age group, when the acquisition of reading ability still continues. No relationships among children‘s fluid intelligence, reading ability and measurements of eye movements were reported.

  11. The effects of eye movements on emotional memories : using an objective measure of cognitive load

    NARCIS (Netherlands)

    van Veen, Suzanne C.; Engelhard, Iris M.; van den Hout, Marcel A.

    2016-01-01

    Background: Eyemovement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. The workingmemory (WM) theory explains its efficacy: recall of an aversivememory and making eye movements (EM) both produce cognitive load, and competition for the limited WM

  12. EMDR Effects on Pursuit Eye Movements

    OpenAIRE

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

    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 Eyelin...

  13. Eye movements and information geometry.

    Science.gov (United States)

    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.

  14. The effects of eye movements on emotional memories: using an objective measure of cognitive load

    Directory of Open Access Journals (Sweden)

    Suzanne C. van Veen

    2016-07-01

    Full Text Available Background: Eye movement desensitization and reprocessing (EMDR is an effective treatment for posttraumatic stress disorder. The working memory (WM theory explains its efficacy: recall of an aversive memory and making eye movements (EM both produce cognitive load, and competition for the limited WM resources reduces the memory's vividness and emotionality. The present study tested several predictions from WM theory. Objective: We hypothesized that 1 recall of an aversive autobiographical memory loads WM compared to no recall, and 2 recall with EM reduces the vividness, emotionality, and cognitive load of recalling the memory more than only recall or only cognitive effort (i.e., recall of an irrelevant memory with EM. Method: Undergraduates (N=108 were randomly assigned to one of three conditions: 1 recall relevant memory with EM, 2 recall relevant memory without EM, and 3 recall irrelevant memory with EM. We used a random interval repetition task to measure the cognitive load of recalling the memory. Participants responded to randomly administered beeps, with or without recalling the memory. The degree to which participants slow down during recall provides an index of cognitive load. We measured the cognitive load and self-reported vividness and emotionality before, halfway through (8×24 s, and after (16×24 s the intervention. Results: Reaction times slowed down during memory recall compared to no recall. The recall relevant with EM condition showed a larger decrease in self-reported vividness and emotionality than the control conditions. The cognitive load of recalling the memory also decreased in this condition but not consistently more than in the control conditions. Conclusions: Recall of an aversive memory loads WM, but drops in vividness and emotionality do not immediately reduce the cognitive load of recalling the memory. More research is needed to find objective measures that could capture changes in the quality of the memory.

  15. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements: fix...

  16. Compensatory eye movements in mice

    NARCIS (Netherlands)

    A.M. van Alphen (Adriaan)

    2002-01-01

    textabstractThis thesis will address the generation of compensatory eye movements in naturally mutated or genetically modified mice. The reason for generating compensatory eye movements is solely related to the requirements for good vision. In a subject moving through its environment the projection

  17. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements...

  18. Eye movement-based measures of development of spatial contrast sensitivity in infants.

    Science.gov (United States)

    Hainline, L; Abramov, I

    1997-10-01

    This study presents spatial contrast sensitivity functions from 66 infants ranging in age from 12 to 146 days. Functions were derived using a behavioral method based on eye movements; in this method, the subject viewed drifting sinusoidal gratings while an experimenter, who did not know the direction of stimulus drift, voted on that direction based only on the record of the subject's eye movements. Results show that there is a marked increase in contrast sensitivity across age, as well as a modest shift of the peak of the function and of the acuity limit to higher spatial frequencies. However, when normalized with respect to peak frequency and peak sensitivity, the functions at all ages have the same general shape and can be fit with a standard template curve used to describe contrast sensitivity in the adult visual system; that is, even the youngest infants clearly show a drop in sensitivity at frequencies below the peaks of their functions.

  19. Eye Movements When Viewing Advertisements

    Directory of Open Access Journals (Sweden)

    Emily eHiggins

    2014-03-01

    Full Text Available 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.

  20. Eye movements when viewing advertisements

    Science.gov (United States)

    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

  1. Abnormal Fixational Eye Movements in Amblyopia.

    Science.gov (United States)

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

    2016-01-01

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

  2. Pain ameliorating effect of eye movement desensitization.

    Science.gov (United States)

    Hekmat, H; Groth, S; Rogers, D

    1994-06-01

    This study explores the efficacy of eye movement desensitization and reprocessing (EMD/R) in the management of acute pain induced by hand exposures to ice water. Thirty participants were randomly assigned to one of the following interventions: (a) eye movement desensitization and reprocessing, (b) eye movement desensitization with music (EMD/M), and (c) control. The EMD/R participants focused on negative experiences associated with exposure to ice water, generated positive self-talk, and diverted their attention away from pain by focusing on a rapidly moving light on a monitor. The EMD with music group received eye movement desensitization coupled with preferred music. Repeated measures univariate and multivariate analysis of covariance was used to analyze the data. Results indicated that both procedures alleviated participants' pain to a similar degree and significantly more than the control, P < 0.05.

  3. EMDR effects on pursuit eye movements.

    Science.gov (United States)

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

    2010-05-21

    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.

  4. Relationship between saccadic eye movements and cortical activity as measured by fMRI

    DEFF Research Database (Denmark)

    Kimmig, H.; Greenlee, M.W.; Gondan, Matthias;

    2001-01-01

    quantitative changes in cortical activity associated with qualitative changes in the saccade task for comparable levels of saccadic activity. All experiments required the simultaneous acquisition of eye movement and fMRI data. For this purpose we used a new high-resolution limbus-tracking technique...... that repeated processing of saccades is integrated over time in the BOLD response. In contrast, there was no comparable BOLD change with variation of saccade amplitude. This finding speaks for a topological rather than activity-dependent coding of saccade amplitudes in most cortical regions. In the experiments...

  5. Development of Estimating Equation of Machine Operational Skill by Utilizing Eye Movement Measurement and Analysis of Stress and Fatigue

    Directory of Open Access Journals (Sweden)

    Satoshi Suzuki

    2013-01-01

    Full Text Available For an establishment of a skill evaluation method for human support systems, development of an estimating equation of the machine operational skill is presented. Factors of the eye movement such as frequency, velocity, and moving distance of saccade were computed using the developed eye gaze measurement system, and the eye movement features were determined from these factors. The estimating equation was derived through an outlier test (to eliminate nonstandard data and a principal component analysis (to find dominant components. Using a cooperative carrying task (cc-task simulator, the eye movement and operational data of the machine operators were recorded, and effectiveness of the derived estimating equation was investigated. As a result, it was confirmed that the estimating equation was effective strongly against actual simple skill levels (r=0.56–0.84. In addition, effects of internal condition such as fatigue and stress on the estimating equation were analyzed. Using heart rate (HR and coefficient of variation of R-R interval (Cvrri. Correlation analysis between these biosignal indexes and the estimating equation of operational skill found that the equation reflected effects of stress and fatigue, although the equation could estimate the skill level adequately.

  6. Using Reading Times and Eye-Movements to Measure Cognitive Engagement

    Science.gov (United States)

    Miller, Brian W.

    2015-01-01

    Self-paced reading and eye-tracking can be used to measure microlevel student engagement during science instruction. These methods imply a definition of engagement as the quantity and quality of mental resources directed at an object and the emotions and behaviors entailed. This definition is theoretically supported by models of reading…

  7. Yarbus, Eye Movements, and Vision

    Directory of Open Access Journals (Sweden)

    Benjamin W Tatler

    2010-04-01

    Full Text Available 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.

  8. Eye movement monitoring of memory.

    Science.gov (United States)

    Ryan, Jennifer D; Riggs, Lily; McQuiggan, Douglas A; McQuiggan, Doug

    2010-08-15

    Explicit (often verbal) reports are typically used to investigate memory (e.g. "Tell me what you remember about the person you saw at the bank yesterday."), however such reports can often be unreliable or sensitive to response bias, and may be unobtainable in some participant populations. Furthermore, explicit reports only reveal when information has reached consciousness and cannot comment on when memories were accessed during processing, regardless of whether the information is subsequently accessed in a conscious manner. Eye movement monitoring (eye tracking) provides a tool by which memory can be probed without asking participants to comment on the contents of their memories, and access of such memories can be revealed on-line. Video-based eye trackers (either head-mounted or remote) use a system of cameras and infrared markers to examine the pupil and corneal reflection in each eye as the participant views a display monitor. For head-mounted eye trackers, infrared markers are also used to determine head position to allow for head movement and more precise localization of eye position. Here, we demonstrate the use of a head-mounted eye tracking system to investigate memory performance in neurologically-intact and neurologically-impaired adults. Eye movement monitoring procedures begin with the placement of the eye tracker on the participant, and setup of the head and eye cameras. Calibration and validation procedures are conducted to ensure accuracy of eye position recording. Real-time recordings of X,Y-coordinate positions on the display monitor are then converted and used to describe periods of time in which the eye is static (i.e. fixations) versus in motion (i.e., saccades). Fixations and saccades are time-locked with respect to the onset/offset of a visual display or another external event (e.g. button press). Experimental manipulations are constructed to examine how and when patterns of fixations and saccades are altered through different types of prior

  9. Relationship between saccadic eye movements and cortical activity as measured by fMRI

    DEFF Research Database (Denmark)

    Kimmig, H.; Greenlee, M.W.; Gondan, Matthias;

    2001-01-01

    quantitative changes in cortical activity associated with qualitative changes in the saccade task for comparable levels of saccadic activity. All experiments required the simultaneous acquisition of eye movement and fMRI data. For this purpose we used a new high-resolution limbus-tracking technique......We investigated the quantitative relationship between saccadic activity (as reflected in frequency of occurrence and amplitude of saccades) and blood oxygenation level dependent (BOLD) changes in the cerebral cortex using functional magnetic resonance imaging (fMRI). Furthermore, we investigated....... The latter finding is taken to indicate a more demanding cortical processing in the "anti" task than the "pro" task, which could explain the observed difference in BOLD activation. We hold that a quantitative analysis of saccade parameters (especially saccade frequency and latency) is important...

  10. Eye Movement Disorders in Dyslexia. Final Report.

    Science.gov (United States)

    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…

  11. Eye movement as a biomarker of schizophrenia: Using an integrated eye movement score.

    Science.gov (United States)

    Morita, Kentaro; Miura, Kenichiro; Fujimoto, Michiko; Yamamori, Hidenaga; Yasuda, Yuka; Iwase, Masao; Kasai, Kiyoto; Hashimoto, Ryota

    2017-02-01

    Studies have shown that eye movement abnormalities are possible neurophysiological biomarkers for schizophrenia. The aim of this study was to investigate the utility of eye movement abnormalities in identifying patients with schizophrenia from healthy controls. Eighty-five patients with schizophrenia and 252 healthy controls participated in this study. Eye movement measures were collected from free viewing, fixation stability, and smooth pursuit tests. In an objective and stepwise method, eye movement measures were extracted to create an integrated eye movement score. The discriminant analysis resulted in three eye movement measures; the scanpath length during the free viewing test, the horizontal position gain during the fast Lissajous paradigm of the smooth pursuit test, and the duration of fixations during the far distractor paradigm of the fixation stability test. An integrated score using these variables can distinguish patients with schizophrenia from healthy controls with 82% accuracy. The integrated score was correlated with Wechsler Adult Intelligence Scale-Third Edition full scale IQ, Positive and Negative Syndrome Scale scores, and chlorpromazine equivalents, with different correlation patterns in the three eye movement measures used. The discriminant analysis in subgroups matched for age, sex, years of education, and premorbid IQ revealed a sustained classification rate. We established an integrated eye movement score with high classification accuracy between patients with schizophrenia and healthy controls, although there was a significant effect of medication. This study provides further evidence of the utility of eye movement abnormalities in schizophrenia pathology and treatment. © 2016 The Authors. Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

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

    Directory of Open Access Journals (Sweden)

    Takao Imai

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

  13. Eye-movements and ongoing task processing.

    Science.gov (United States)

    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.

  14. Learning-induced changes in attentional allocation during categorization: a sizable catalog of attention change as measured by eye movements.

    Directory of Open Access Journals (Sweden)

    Caitlyn M McColeman

    Full Text Available Learning how to allocate attention properly is essential for success at many categorization tasks. Advances in our understanding of learned attention are stymied by a chicken-and-egg problem: there are no theoretical accounts of learned attention that predict patterns of eye movements, making data collection difficult to justify, and there are not enough datasets to support the development of a rich theory of learned attention. The present work addresses this by reporting five measures relating to the overt allocation of attention across 10 category learning experiments: accuracy, probability of fixating irrelevant information, number of fixations to category features, the amount of change in the allocation of attention (using a new measure called Time Proportion Shift - TIPS, and a measure of the relationship between attention change and erroneous responses. Using these measures, the data suggest that eye-movements are not substantially connected to error in most cases and that aggregate trial-by-trial attention change is generally stable across a number of changing task variables. The data presented here provide a target for computational models that aim to account for changes in overt attentional behaviors across learning.

  15. Anticipatory Eye Movements in Congkak

    Directory of Open Access Journals (Sweden)

    Sheryl Chong

    2011-05-01

    Full Text Available Congkak is a traditional Malaysian board game involving two players taking turns to pick up marbles from a series of holes on the board. We used this game as a model to explore the role of anticipatory eye movements during natural actions (in this case serially picking up/putting marbles as novices learnt the game. Prior work on eye and hand movements in natural behaviour shows that much of the demand on the visual system is computed at the moment it is needed and doesn't depend on information acquired from previous fixations. Vision is driven by the task demands. However, anticipatory fixations to upcoming targets of manipulation have recently been shown to confer spatial accuracy and influence the eye-hand latency. We find that experience with the game also influences the deployment of these anticipatory “look-ahead” fixations, and that their influence on eye-hand latency varies with experience. Results suggest that as our experience in Congkak grows, so does our knowledge of the space relationships necessary for task success.

  16. Eye movement-invariant representations in the human visual system.

    Science.gov (United States)

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

    2017-01-01

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

  17. Analyzing Head and Eye Movement System with CORBA

    Directory of Open Access Journals (Sweden)

    Wang Changyuan

    2013-11-01

    Full Text Available In order to study the vestibular system in different organs of movement as well as their collaboration between working mechanism, this paper designs a model of the common object request broker architecture (CORBA for the head and eye movement system based on the vestibular function. By analyzing physiological characteristics of the head and eye movement model, and further introducing the structure features of CORBA. It focus on the component composition and the model design of CORBA components library. According to the physiology work model of head and eye movement, the CORBA model of head and eye movement is established. As well as the structure of the model is designed in real application of head and eye movement measurement system. This paper provides a new way to research the head and eye movement system through using mathematical modeling and application structure which is based on vestibular function.    

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

    NARCIS (Netherlands)

    Lambregts-Rommelse, N.N.J.; Stigchel, S Van der; Sergeant, J.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 movemen

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Saccadic eye movement applications for psychiatric disorders

    Science.gov (United States)

    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

  1. EMDR effects on pursuit eye movements.

    Directory of Open Access Journals (Sweden)

    Zoi Kapoula

    Full Text Available 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.

  2. The Eyes Have It: Hippocampal Activity Predicts Expression of Memory in Eye Movements

    National Research Council Canada - National Science Library

    Hannula, Deborah E; Ranganath, Charan

    2009-01-01

    ...) with concurrent indirect, eye-movement-based memory measures, we obtained evidence that hippocampal activity predicted expressions of relational memory in subsequent patterns of viewing, even when...

  3. Reconstruction of eye movements during blinks

    CERN Document Server

    Baptista, M S; Kliegl, R; Engbert, R; Kurths, J

    2008-01-01

    In eye movement research in reading, the amount of data plays a crucial role for the validation of results. A methodological problem for the analysis of the eye movement in reading are blinks, when readers close their eyes. Blinking rate increases with increasing reading time, resulting in high data losses, especially for older adults or reading impaired subjects. We present a method, based on the symbolic sequence dynamics of the eye movements, that reconstructs the horizontal position of the eyes while the reader blinks. The method makes use of an observed fact that the movements of the eyes before closing or after opening contain information about the eyes movements during blinks. Test results indicate that our reconstruction method is superior to methods that use simpler interpolation approaches. In addition, analyses of the reconstructed data show no significant deviation from the usual behavior observed in readers.

  4. Cursive writing with smooth pursuit eye movements.

    Science.gov (United States)

    Lorenceau, Jean

    2012-08-21

    The eyes never cease to move: ballistic saccades quickly turn the gaze toward peripheral targets, whereas smooth pursuit maintains moving targets on the fovea where visual acuity is best. Despite the oculomotor system being endowed with exquisite motor abilities, any attempt to generate smooth eye movements against a static background results in saccadic eye movements. Although exceptions to this rule have been reported, volitional control over smooth eye movements is at best rudimentary. Here, I introduce a novel, temporally modulated visual display, which, although static, sustains smooth eye movements in arbitrary directions. After brief training, participants gain volitional control over smooth pursuit eye movements and can generate digits, letters, words, or drawings at will. For persons deprived of limb movement, this offers a fast, creative, and personal means of linguistic and emotional expression. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Eye movements predict recollective experience.

    Directory of Open Access Journals (Sweden)

    Tali Sharot

    Full Text Available Previously encountered stimuli can bring to mind a vivid memory of the episodic context in which the stimulus was first experienced ("remembered" stimuli, or can simply seem familiar ("known" stimuli. Past studies suggest that more attentional resources are required to encode stimuli that are subsequently remembered than known. However, it is unclear if the attentional resources are distributed differently during encoding and recognition of remembered and known stimuli. Here, we record eye movements while participants encode photos, and later while indicating whether the photos are remembered, known or new. Eye fixations were more clustered during both encoding and recognition of remembered photos relative to known photos. Thus, recognition of photos that bring to mind a vivid memory for the episodic context in which they were experienced is associated with less distributed overt attention during encoding and recognition. The results suggest that remembering is related to encoding of a few distinct details of a photo rather than the photo as a whole. In turn, during recognition remembering may be trigged by enhanced memory for the salient details of the photos.

  6. Degeneration of rapid eye movement sleep circuitry underlies rapid eye movement sleep behavior disorder.

    Science.gov (United States)

    McKenna, Dillon; Peever, John

    2017-05-01

    During healthy rapid eye movement sleep, skeletal muscles are actively forced into a state of motor paralysis. However, in rapid eye movement sleep behavior disorder-a relatively common neurological disorder-this natural process is lost. A lack of motor paralysis (atonia) in rapid eye movement sleep behavior disorder allows individuals to actively move, which at times can be excessive and violent. At first glance this may sound harmless, but it is not because rapid eye movement sleep behavior disorder patients frequently injure themselves or the person they sleep with. It is hypothesized that the degeneration or dysfunction of the brain stem circuits that control rapid eye movement sleep paralysis is an underlying cause of rapid eye movement sleep behavior disorder. The link between brain stem degeneration and rapid eye movement sleep behavior disorder stems from the fact that rapid eye movement sleep behavior disorder precedes, in the majority (∼80%) of cases, the development of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, which are known to initially cause degeneration in the caudal brain stem structures where rapid eye movement sleep circuits are located. Furthermore, basic science and clinical evidence demonstrate that lesions within the rapid eye movement sleep circuits can induce rapid eye movement sleep-specific motor deficits that are virtually identical to those observed in rapid eye movement sleep behavior disorder. This review examines the evidence that rapid eye movement sleep behavior disorder is caused by synucleinopathic neurodegeneration of the core brain stem circuits that control healthy rapid eye movement sleep and concludes that rapid eye movement sleep behavior disorder is not a separate clinical entity from synucleinopathies but, rather, it is the earliest symptom of these disorders. © 2017 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and

  7. Fetal eye movements on magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Ramona Woitek

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

  8. Fetal eye movements on magnetic resonance imaging.

    Science.gov (United States)

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

    2013-01-01

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

  9. Fetal Eye Movements on Magnetic Resonance Imaging

    Science.gov (United States)

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

    2013-01-01

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

  10. Persistence in eye movement during visual search

    Science.gov (United States)

    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.

  11. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Schenck, C H; Montplaisir, J Y; Frauscher, B

    2013-01-01

    We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD...

  12. Quantifying patterns of dynamics in eye movement to measure goodness in organization of design elements in interior architecture

    Science.gov (United States)

    Mirkia, Hasti; Sangari, Arash; Nelson, Mark; Assadi, Amir H.

    2013-03-01

    Architecture brings together diverse elements to enhance the observer's measure of esthetics and the convenience of functionality. Architects often conceptualize synthesis of design elements to invoke the observer's sense of harmony and positive affect. How does an observer's brain respond to harmony of design in interior spaces? One implicit consideration by architects is the role of guided visual attention by observers while navigating indoors. Prior visual experience of natural scenes provides the perceptual basis for Gestalt of design elements. In contrast, Gestalt of organization in design varies according to the architect's decision. We outline a quantitative theory to measure the success in utilizing the observer's psychological factors to achieve the desired positive affect. We outline a unified framework for perception of geometry and motion in interior spaces, which integrates affective and cognitive aspects of human vision in the context of anthropocentric interior design. The affective criteria are derived from contemporary theories of interior design. Our contribution is to demonstrate that the neural computations in an observer's eye movement could be used to elucidate harmony in perception of form, space and motion, thus a measure of goodness of interior design. Through mathematical modeling, we argue the plausibility of the relevant hypotheses.

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

    Science.gov (United States)

    Spering, Miriam; Carrasco, Marisa

    2015-04-01

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

  14. A new quantitative automatic method for the measurement of non-rapid eye movement sleep electroencephalographic amplitude variability.

    Science.gov (United States)

    Ferri, Raffaele; Rundo, Francesco; Novelli, Luana; Terzano, Mario G; Parrino, Liborio; Bruni, Oliviero

    2012-04-01

    The aim of this study was to arrange an automatic quantitative measure of the electroencephalographic (EEG) signal amplitude variability during non-rapid eye movement (NREM) sleep, correlated with the visually extracted cyclic alternating pattern (CAP) parameters. Ninety-eight polysomnographic EEG recordings of normal controls were used. A new algorithm based on the analysis of the EEG amplitude variability during NREM sleep was designed and applied to all recordings, which were also scored visually for CAP. All measurements obtained with the new algorithm correlated positively with corresponding CAP parameters. In particular, total CAP time correlated with total NREM variability time (r = 0.596; P < 1E-07), light sleep CAP time with light sleep variability time (r = 0.597; P < 1E-07) and slow wave sleep CAP time with slow wave sleep variability time (r = 0.809; P < 1E-07). Only the duration of CAP A phases showed a low correlation with the duration of variability events. Finally, the age-related modifications of CAP time and of NREM variability time were found to be very similar. The new method for the automatic analysis of NREM sleep amplitude variability presented here correlates significantly with visual CAP parameters; its application requires a minimum work time, compared to CAP analysis, and might be used in large studies involving numerous recordings in which NREM sleep EEG amplitude variability needs to be assessed.

  15. Timed and Untimed Grammaticality Judgments Measure Distinct Types of Knowledge: Evidence from Eye-Movement Patterns

    Science.gov (United States)

    Godfroid, Aline; Loewen, Shawn; Jung, Sehoon; Park, Ji-Hyun; Gass, Susan; Ellis, Rod

    2015-01-01

    Grammaticality judgment tests (GJTs) have been used to elicit data reflecting second language (L2) speakers' knowledge of L2 grammar. However, the exact constructs measured by GJTs, whether primarily implicit or explicit knowledge, are disputed and have been argued to differ depending on test-related variables (i.e., time pressure and item…

  16. Control and Functions of Fixational Eye Movements

    Science.gov (United States)

    Rucci, Michele; Poletti, Martina

    2016-01-01

    Humans and other species explore a visual scene by rapidly shifting their gaze 2-3 times every second. Although the eyes may appear immobile in the brief intervals in between saccades, microscopic (fixational) eye movements are always present, even when attending to a single point. These movements occur during the very periods in which visual information is acquired and processed and their functions have long been debated. Recent technical advances in controlling retinal stimulation during normal oculomotor activity have shed new light on the visual contributions of fixational eye movements and their degree of control. The emerging body of evidence, reviewed in this article, indicates that fixational eye movements are important components of the strategy by which the visual system processes fine spatial details, enabling both precise positioning of the stimulus on the retina and encoding of spatial information into the joint space-time domain.

  17. Viewpoint Consistency: An Eye Movement Study

    Directory of Open Access Journals (Sweden)

    Filipe Cristino

    2012-05-01

    Full Text Available Eye movements have been widely studied, using images and videos in laboratories or portable eye trackers in the real world. Although a good understanding of the saccadic system and extensive models of gaze have been developed over the years, only a few studies have focused on the consistency of eye movements across viewpoints. We have developed a new technique to compute and map the depth of collected eye movements on stimuli rendered from 3D mesh objects using a traditional corneal reflection eye tracker (SR Eyelink 1000. Having eye movements mapped into 3D space (and not on an image space allowed us to compare fixations across viewpoints. Fixation sequences (scanpaths were also studied across viewpoints using the ScanMatch method (Cristino et al 2010, Behavioural and Research Methods 42, 692–700, extended to work with 3D eye movements. In a set of experiments where participants were asked to perform a recognition task on either a set of objects or faces, we recorded their gaze while performing the task. Participants either viewed the stimuli in 2D or using anaglyph glasses. The stimuli were shown from different viewpoints during the learning and testing phases. A high degree of gaze consistency was found across the different viewpoints, particularly between learning and testing phases. Scanpaths were also similar across viewpoints, suggesting not only that the gazed spatial locations are alike, but also their temporal order.

  18. Relations between Psychological Status and Eye Movements

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2015-06-01

    Full Text Available Relations between psychological status and eye movements are found through experiments with readings of different types of documents as well as playing games. Psychological status can be monitored with Electroencephalogram: EEG sensor while eye movements can be monitored with Near Infrared: NIR cameras with NIR Light Emission Diode: LED. EEG signals are suffred from noises while eye movement can be acquired without any influence from nise. Therefore, psychlogical status can be monitored with eye movement detection instead of EEG signal acquisition if there is relation between both. Through the experiments, it is found strong relation between both. In particular, relation between the number of rapid changes of line of sight directions and relatively high frequency components of EEG signals is found. It is also found that the number of rapid eye movement is counted when the users are reading the documents. The rapid eye movement is defined as 10 degrees of look angle difference for one second. Not only when the users change the lines in the document, but also when the users feel a difficulty for reading words in the document, the users’ line of sight direction moves rapidly.

  19. A Review on Eye Movement Studies in Childhood and Adolescent Psychiatry

    Science.gov (United States)

    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…

  20. A Review on Eye Movement Studies in Childhood and Adolescent Psychiatry

    Science.gov (United States)

    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…

  1. How Were Eye Movements Recorded Before Yarbus?

    Science.gov (United States)

    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. Impact of Air Movement on Eye Symptoms

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Sakoi, Tomonori; Kolencíková, Sona

    2013-01-01

    The impact of direction, oscillation and temperature of isothermal room air movement on eye discomfort and tear film quality was studied. Twenty-four male subjects participated in the experiment. Horizontal air movement against the face and chest was generated by a large desk fan – LDF and a smal...

  3. Multipulse control of saccadic eye movements

    Science.gov (United States)

    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.

  4. A Note on Eye Movement

    CERN Document Server

    Bolina, O; Bolina, Oscar

    1998-01-01

    In a simplified fashion, the motion of the eyeball in its orbit consists of rotations around a fixed point. Therefore, this motion can be described in terms of the Euler's angles of rigid body dynamics. However, there is a physiological constraint in the motion of the eye which reduces to two its degrees of freedom. This paper reviews the basic features of the kinematics of the eye and the laws governing its motion.

  5. Coordinated control of eye and hand movements in dynamic reaching

    NARCIS (Netherlands)

    Neggers, S.F.W.; Bekkering, H.

    2002-01-01

    In the present study, we integrated two recent, at first sight contradictory findings regarding the question whether saccadic eye movements can be generated to a newly presented target during an ongoing hand movement. Saccades were measured during so-called adaptive and sustained pointing

  6. Coordinated control of eye and hand movements in dynamic reaching

    NARCIS (Netherlands)

    Neggers, SFW; Bekkering, H

    2002-01-01

    In the present study, we integrated two recent, at first sight contradictory findings regarding the question whether saccadic eye movements can be generated to a newly presented target during an ongoing hand movement. Saccades were measured during so-called adaptive and sustained pointing conditions

  7. Hypothesized eye movements of neurolinguistic programming: a statistical artifact.

    Science.gov (United States)

    Farmer, A; Rooney, R; Cunningham, J R

    1985-12-01

    Neurolinguistic programming's hypothesized eye-movements were measured independently from videotapes of 30 subjects, aged 15 to 76 yr., who were asked to recall visual pictures, recorded audio sounds, and textural objects. chi 2 indicated that subjects' responses were significantly different from those predicted. When chi 2 comparisons were weighted by number of eye positions assigned to each modality (3 visual, 3 auditory, 1 kinesthetic), subjects' responses did not differ significantly from the expected pattern. These data indicate that the eye-movement hypothesis may represent randomly occurring rather than sensory-modality-related positions.

  8. An Analog VLSI Saccadic Eye Movement System

    OpenAIRE

    1994-01-01

    In an effort to understand saccadic eye movements and their relation to visual attention and other forms of eye movements, we - in collaboration with a number of other laboratories - are carrying out a large-scale effort to design and build a complete primate oculomotor system using analog CMOS VLSI technology. Using this technology, a low power, compact, multi-chip system has been built which works in real-time using real-world visual inputs. We describe in this paper the performance of a...

  9. Eye mechanics and their implications for eye movement control

    NARCIS (Netherlands)

    Koene, Ansgar Roald

    2002-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Michael ePlöchl

    2012-10-01

    Full Text Available 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 show that eye movement artifacts consist of several components, which arise from different sources. These include corneo-retinal dipole changes, saccadic spike potentials and eyelid movements. Moreover, we demonstrate that depending on electrode site, gaze direction and choice of reference these components contribute differently to the measured signal. Therefore they cannot be removed by regression-based correction methods, as these inevitably over- or under-correct individual artifact components. Finally we propose a correction procedure based on Independent Component Analysis (ICA. This procedure uses eye tracker information to reliably and objectively identify eye-artifact related ICA-components in an automated manner. We demonstrate that this approach allows removing or substantially reducing ocular artifacts including microsaccades without affecting the signal originating from brain sources. In conclusion the proposed method does not only provide a tool for detecting and correcting eye artifacts in standard EEG-paradigms but it also permits to study EEG-activity during eye tracking experiments and thus to investigate neural mechanisms of eye movement control and visual attention under natural conditions.

  11. Eye-movements During Translation

    DEFF Research Database (Denmark)

    Balling, Laura Winther

    2013-01-01

    Translation process research or TPR, the study of the cognitive processes involved in translation, is a relatively new field characterised by small-scale studies with few participants and variables. However, the translation process is characterised by much variation between different translators......, texts, tasks and languages, and larger-scale investigations are therefore highly desirable. To that end, we have publicly released the CRITT TPR database which currently contains data from 845 translation sessions but is continually extended. The database includes information about the source and target...... texts as well as both eye-tracking and keylogging data. Based on this database, I present a large-scale analysis of gaze on the source text based on 91 translators' translations of six different texts from English into four different target languages. I use mixed-effects modelling to compare from...

  12. Saccadic eye movement applications for psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Bittencourt J

    2013-09-01

    Med/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. Keywords: depression, bipolar disorder, attention-deficit hyperactivity disorder, schizophrenia, anxiety disorder

  13. Pharmacological Treatment Effects on Eye Movement Control

    Science.gov (United States)

    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…

  14. Lateral Eye Movement Behavior in Children.

    Science.gov (United States)

    Reynolds, Cecil R.; Kaufman, Alan S.

    1980-01-01

    The conjugate lateral eye movement phenomenon was investigated for 52 children aged 2 through 10 using both spatial and verbal-analytic questions. The phenomenon was observed in 50 subjects and appeared well-established by age 3 1/2. Some interesting developmental findings and discrepancies with the results of adult studies are noted. (Author/SJL)

  15. Eye Movements and Visual Memory for Scenes

    Science.gov (United States)

    2005-01-01

    Di Lo110,V. (1980). Temporal integration in visual memory. Journal of Experimental Pychology : General 109,7597. Duhamel, J. R, Colby, C. L, and...H. (1978). Direction-specific motion thresholds for abnormal 9,441474. image shifts during saccadic eye movement. Perception and Psychophyn’cs

  16. Eye Movements in Implicit Artificial Grammar Learning

    Science.gov (United States)

    Silva, Susana; Inácio, Filomena; Folia, Vasiliki; Petersson, Karl Magnus

    2017-01-01

    Artificial grammar learning (AGL) has been probed with forced-choice behavioral tests (active tests). Recent attempts to probe the outcomes of learning (implicitly acquired knowledge) with eye-movement responses (passive tests) have shown null results. However, these latter studies have not tested for sensitivity effects, for example, increased…

  17. Rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical...

  18. Do common systems control eye movements and motion extrapolation?

    Science.gov (United States)

    Makin, Alexis D J; Poliakoff, Ellen

    2011-07-01

    People are able to judge the current position of occluded moving objects. This operation is known as motion extrapolation. It has previously been suggested that motion extrapolation is independent of the oculomotor system. Here we revisited this question by measuring eye position while participants completed two types of motion extrapolation task. In one task, a moving visual target travelled rightwards, disappeared, then reappeared further along its trajectory. Participants discriminated correct reappearance times from incorrect (too early or too late) with a two-alternative forced-choice button press. In the second task, the target travelled rightwards behind a visible, rectangular occluder, and participants pressed a button at the time when they judged it should reappear. In both tasks, performance was significantly different under fixation as compared to free eye movement conditions. When eye movements were permitted, eye movements during occlusion were related to participants' judgements. Finally, even when participants were required to fixate, small changes in eye position around fixation (<2°) were influenced by occluded target motion. These results all indicate that overlapping systems control eye movements and judgements on motion extrapolation tasks. This has implications for understanding the mechanism underlying motion extrapolation.

  19. Second-language experience modulates first- and second-language word frequency effects: evidence from eye movement measures of natural paragraph reading.

    Science.gov (United States)

    Whitford, Veronica; Titone, Debra

    2012-02-01

    We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate whether the degree of current L2 exposure modulates the relative size of L1 and L2 frequency effects (FEs). The results showed that bilinguals displayed larger L2 than L1 FEs during both early- and late-stage eye movement measures, which are taken to reflect initial lexical access and postlexical access, respectively. Moreover, the magnitude of L2 FEs was inversely related to current L2 exposure, such that lower levels of L2 exposure led to larger L2 FEs. In contrast, during early-stage reading measures, bilinguals with higher levels of current L2 exposure showed larger L1 FEs than did bilinguals with lower levels of L2 exposure, suggesting that increased L2 experience modifies the earliest stages of L1 lexical access. Taken together, the findings are consistent with implicit learning accounts (e.g., Monsell, 1991), the weaker links hypothesis (Gollan, Montoya, Cera, Sandoval, Journal of Memory and Language, 58:787-814, 2008), and current bilingual visual word recognition models (e.g., the bilingual interactive activation model plus [BIA+]; Dijkstra & van Heuven, Bilingualism: Language and Cognition, 5:175-197, 2002). Thus, amount of current L2 exposure is a key determinant of FEs and, thus, lexical activation, in both the L1 and L2.

  20. Contact-Free Cognitive Load Recognition Based on Eye Movement

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2016-01-01

    Full Text Available The cognitive overload not only affects the physical and mental diseases, but also affects the work efficiency and safety. Hence, the research of measuring cognitive load has been an important part of cognitive load theory. In this paper, we proposed a method to identify the state of cognitive load by using eye movement data in a noncontact manner. We designed a visual experiment to elicit human’s cognitive load as high and low state in two light intense environments and recorded the eye movement data in this whole process. Twelve salient features of the eye movement were selected by using statistic test. Algorithms for processing some features are proposed for increasing the recognition rate. Finally we used the support vector machine (SVM to classify high and low cognitive load. The experimental results show that the method can achieve 90.25% accuracy in light controlled condition.

  1. Eye movement targets are released from visual crowding.

    Science.gov (United States)

    Harrison, William J; Mattingley, Jason B; Remington, Roger W

    2013-02-13

    Our ability to recognize objects in peripheral vision is impaired when other objects are nearby (Bouma, 1970). This phenomenon, known as crowding, is often linked to interactions in early visual processing that depend primarily on the retinal position of visual stimuli (Pelli, 2008; Pelli and Tillman, 2008). Here we tested a new account that suggests crowding is influenced by spatial information derived from an extraretinal signal involved in eye movement preparation. We had human observers execute eye movements to crowded targets and measured their ability to identify those targets just before the eyes began to move. Beginning ∼50 ms before a saccade toward a crowded object, we found that not only was there a dramatic reduction in the magnitude of crowding, but the spatial area within which crowding occurred was almost halved. These changes in crowding occurred despite no change in the retinal position of target or flanking stimuli. Contrary to the notion that crowding depends on retinal signals alone, our findings reveal an important role for eye movement signals. Eye movement preparation effectively enhances object discrimination in peripheral vision at the goal of the intended saccade. These presaccadic changes may enable enhanced recognition of visual objects in the periphery during active search of visually cluttered environments.

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

    Science.gov (United States)

    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.

  3. The eyes know: eye movements as a veridical index of memory.

    Science.gov (United States)

    Hannula, Deborah E; Baym, Carol L; Warren, David E; Cohen, Neal J

    2012-03-01

    In two experiments, we examined whether observers' eye movements distinguish studied faces from highly similar novel faces. Participants' eye movements were monitored while they viewed three-face displays. Target-present displays contained a studied face and two morphed faces that were visually similar to it; target-absent displays contained three morphed faces that were visually similar to a studied, but not tested, face. On each trial in a test session, participants were instructed to choose the studied face if it was present or a random face if it was not and then to indicate whether the chosen face was studied. Whereas manipulating visual similarity in target-absent displays influenced the rate of false endorsements of nonstudied items as studied, eye movements proved impervious to this manipulation. Studied faces were viewed disproportionately from 1,000 to 2,000 ms after display onset and from 1,000 to 500 ms before explicit identification. Early viewing also distinguished studied faces from faces incorrectly endorsed as studied. Our findings show that eye movements provide a relatively pure index of past experience that is uninfluenced by explicit response strategies, and suggest that eye movement measures may be of practical use in applied settings.

  4. Physiological correlates of eye movement desensitization and reprocessing.

    Science.gov (United States)

    Elofsson, Ulf O E; von Schèele, Bo; Theorell, Töres; Söndergaard, Hans Peter

    2008-05-01

    Eye movement desensitization and reprocessing (EMDR) is an established treatment for post-traumatic stress disorder (PTSD). However, its working mechanism remains unclear. This study explored physiological correlates of eye movements during EMDR in relation to current hypotheses; distraction, conditioning, orienting response activation, and REM-like mechanisms. During EMDR therapy, fingertip temperature, heart rate, skin conductance, expiratory carbon dioxide level, and blood pulse oximeter oxygen saturation, were measured in male subjects with PTSD. The ratio between the low and high frequency components of the heart rate power spectrum (LF/HF) were computed as measures of autonomic balance. Respiratory rate was calculated from the carbon dioxide trace. Stimulation shifted the autonomic balance as indicated by decreases in heart rate, skin conductance and LF/HF-ratio, and an increased finger temperature. The breathing frequency and end-tidal carbon dioxide increased; oxygen saturation decreased during eye movements. In conclusion, eye movements during EMDR activate cholinergic and inhibit sympathetic systems. The reactivity has similarities with the pattern during REM-sleep.

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

    Science.gov (United States)

    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.

  6. Quantitative linking hypotheses for infant eye movements.

    Directory of Open Access Journals (Sweden)

    Daniel Yurovsky

    Full Text Available The study of cognitive development hinges, largely, on the analysis of infant looking. But analyses of eye gaze data require the adoption of linking hypotheses: assumptions about the relationship between observed eye movements and underlying cognitive processes. We develop a general framework for constructing, testing, and comparing these hypotheses, and thus for producing new insights into early cognitive development. We first introduce the general framework--applicable to any infant gaze experiment--and then demonstrate its utility by analyzing data from a set of experiments investigating the role of attentional cues in infant learning. The new analysis uncovers significantly more structure in these data, finding evidence of learning that was not found in standard analyses and showing an unexpected relationship between cue use and learning rate. Finally, we discuss general implications for the construction and testing of quantitative linking hypotheses. MATLAB code for sample linking hypotheses can be found on the first author's website.

  7. Eye movements in ataxia-telangiectasia.

    Science.gov (United States)

    Baloh, R W; Yee, R D; Boder, E

    1978-11-01

    The spectrum of eye movement disorders in six patients with ataxia-telangiectasia at different stages of progression was assessed quantitatively by electrooculography. All patients demonstrated abnormalities of voluntary and involuntary saccades. The youngest and least involved patient had significantly increased reaction times of voluntary saccades, but normal accuracy and velocity. The other patients demonstrated increased reaction times and marked hypometria of horizontal and vertical voluntary saccades. Saccade velocity remained normal. Vestibular and optokinetic fast components (involuntary saccades) had normal amplitude and velocity but the eyes deviated tonically in the direction of the slow component. We conclude that patients with ataxia-telangiectasia have a defect in the initiation of voluntary and involuntary saccades in the earliest stages. These findings are distinctly different from those in other familial cerebellar atrophy syndromes.

  8. Eye movements during visual search in patients with glaucoma

    Directory of Open Access Journals (Sweden)

    Smith Nicholas D

    2012-08-01

    Full Text Available Abstract Background Glaucoma has been shown to lead to disability in many daily tasks including visual search. This study aims to determine whether the saccadic eye movements of people with glaucoma differ from those of people with normal vision, and to investigate the association between eye movements and impaired visual search. Methods Forty patients (mean age: 67 [SD: 9] years with a range of glaucomatous visual field (VF defects in both eyes (mean best eye mean deviation [MD]: –5.9 (SD: 5.4 dB and 40 age-related people with normal vision (mean age: 66 [SD: 10] years were timed as they searched for a series of target objects in computer displayed photographs of real world scenes. Eye movements were simultaneously recorded using an eye tracker. Average number of saccades per second, average saccade amplitude and average search duration across trials were recorded. These response variables were compared with measurements of VF and contrast sensitivity. Results The average rate of saccades made by the patient group was significantly smaller than the number made by controls during the visual search task (P = 0.02; mean reduction of 5.6% (95% CI: 0.1 to 10.4%. There was no difference in average saccade amplitude between the patients and the controls (P = 0.09. Average number of saccades was weakly correlated with aspects of visual function, with patients with worse contrast sensitivity (PR logCS; Spearman’s rho: 0.42; P = 0.006 and more severe VF defects (best eye MD; Spearman’s rho: 0.34; P = 0.037 tending to make less eye movements during the task. Average detection time in the search task was associated with the average rate of saccades in the patient group (Spearman’s rho = −0.65; P  Conclusions The average rate of saccades made during visual search by this group of patients was fewer than those made by people with normal vision of a similar average age. There was wide variability in saccade rate in the patients

  9. Eye movement monitoring reveals differential influences of emotion on memory

    Directory of Open Access Journals (Sweden)

    Lily Riggs

    2010-11-01

    Full Text Available Research shows that memory for emotional aspects of an event may be enhanced at the cost of impaired memory for surrounding peripheral details. However, this has only been assessed directly via verbal reports which reveal the outcome of a long stream of processing but cannot shed light on how/when emotion may affect the retrieval process. In the present experiment, eye movement monitoring was used as an indirect measure of memory as it can reveal aspects of online memory processing. For example, do emotions modulate the nature of memory representations or the speed with which such memories can be accessed? Participants viewed central negative and neutral scenes surrounded by three neutral objects and after a brief delay, memory was assessed indirectly via eye movement monitoring and then directly via verbal reports. Consistent with the previous literature, emotion enhanced central and impaired peripheral memory as indexed by eye movement scanning and verbal reports. This suggests that eye movement scanning may contribute and/or is related to conscious access of memory. However, the central/peripheral tradeoff effect was not observed in an early measure of eye movement behavior, i.e. participants were faster to orient to a critical region of change in the periphery irrespective of whether it was previously studied in a negative or neutral context. These findings demonstrate emotion’s differential influences on different aspects of retrieval. In particular, emotion appears to affect the detail within, and/or the evaluation of, stored memory representations, but it may not affect the initial access to those representations.

  10. Eye Movements and Visual Search: A Bibliography,

    Science.gov (United States)

    1983-01-01

    0D, rOK 221 Feinstein, R.; Williams , W.J. An al.orithmic nodel for aspects of visual information processing and eye movements. Proceedings of the 23rd...RR-4-SER-B, 7-3, June 1981. INS, RED 320 Hochberg, J. Components of literacy: speculations and exploratory research. In H. Levin & J.P. Williams (Eds...selection accuracy and exgosure in visual search. Perception, 1975, 4, 411-41. VIS, TAC, REC 652 Spady , Jr.; A.A. Airline pilots’ scan behaviour

  11. Involuntary Eye Movement during Fixation is Influenced by Spatio-Temporal Frequency of Visual Stimuli

    Directory of Open Access Journals (Sweden)

    Masae Yokota

    2011-05-01

    Full Text Available Involuntary eye movement during fixation is essential for visual information acquisition. Previous studies have suggested that such eye movement depends on the attributes of visual stimuli (e.g. Yokota, APCV2010. In this study, we focus on spatio-temporal frequency, as an attribute of visual stimuli in order to understand spatio-temporal frequency property in the pathway of human vision. We measured eye movement during fixation for three subjects when 16 random-dot dynamic textures that have various frequency bands in spatially and temporally, are presented to the subjects as visual stimuli. The result shows that eye movement depends on the spatio-temporal frequency of visual stimuli. The eye movement includes higher frequency components, in other words, higher velocity components, when visual stimulus has higher spatial frequency and/or higher temporal frequency. Future detailed experiments will show that involuntary eye movement during fixation might be influenced by spatio-temporal frequency sensitivity in vision.

  12. Eye movements in ephedrone-induced parkinsonism.

    Directory of Open Access Journals (Sweden)

    Cecilia Bonnet

    Full Text Available 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.

  13. Improvement of Reading Speed and Eye Movements

    Directory of Open Access Journals (Sweden)

    Kenji Yokoi

    2011-05-01

    Full Text Available Although many studies have examined eye movements in reading, little is known which factors differentiate slow and fast readers. Recently, Rayner et al. (2010 reported that fast readers had a larger effective visual field than did slow readers by using the gaze-contingent window method. The fast readers they selected, however, may have acquired better attentional skills inherently or through long experience, and this visual superiority would improve reading performance. To clarify this issue, we investigated eye movements in reading while practicing speed reading. Participants (approx. 600 letters per minute in Japanese exercised speed reading programs for half an hour per day for about 30 days. Reading performance of Japanese editorial articles was recorded every five days of training by the gaze-contingent window method. Our results showed that the size of the effective visual field did not increase in the same manner as reading speed (up to 1000 lpm. Instead, we found that saccadic length became longer and less varied. Fixation duration and the number of regressions were also reduced. These findings suggest that efficiency of comprehension at a single gaze may be the important factor for reading speed.

  14. Saccadic Eye Movements in Anorexia Nervosa.

    Science.gov (United States)

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

    2016-01-01

    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. 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). 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. The results suggest a potential role of GABA in the superior colliculus in the psychopathology of AN.

  15. Saccadic Eye Movements in Anorexia Nervosa.

    Directory of Open Access Journals (Sweden)

    Andrea Phillipou

    Full Text Available 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.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.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.The results suggest a potential role of GABA in the superior colliculus in the psychopathology of AN.

  16. Eye movement identification based on accumulated time feature

    Science.gov (United States)

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

    2017-06-01

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

  17. The Recording of Eye-movements during Sleep

    Institute of Scientific and Technical Information of China (English)

    赵明

    2005-01-01

    An American scientist named William Dement published experiments dealing with the recording of eye -movements during sleep.He showed that the common person's sleep is interrupted from time to time by special eye-movements,some floating and slow,others quick and rapid.People woken during these periods of eye-movements generally reported that they had been dreaming. When woken at other times they reported no dreams.

  18. Revisiting the relationship between hand preference and lateral eye movement

    OpenAIRE

    Indiwar Misra; Damodar Suar; Manas K. Mandal

    2010-01-01

    The study examines the relationship between hand preference and conjugate lateral eye movements. The sample comprised of 224 persons. The hand preference was assessed using a handedness inventory. Conjugate lateral eye movements were elicited in response to verbal and spatial questions among left-, mixed- and right-handers. The left- and mixed-handers exhibit significantly greater number of conjugate lateral eye movements than the right-handers. On the verbal task, right-handers exhibit right...

  19. Impaired Saccadic Eye Movement in Primary Open-angle Glaucoma

    DEFF Research Database (Denmark)

    Lamirel, Cédric; Milea, Dan; Cochereau, Isabelle

    2013-01-01

    PURPOSE:: Our study aimed at investigating the extent to which saccadic eye movements are disrupted in patients with primary open-angle glaucoma (POAG). This approach followed upon the discovery of differences in the eye-movement behavior of POAG patients during the exploration of complex visual...... scenes. METHODS:: The eye movements of 8 POAG patients and 4 healthy age-matched controls were recorded. Four of the patients had documented visual field scotoma, and 4 had no identifiable scotoma on visual field testing. The eye movements were monitored as the observers watched static and kinetic...

  20. Eye movement monitoring reveals differential influences of emotion on memory

    OpenAIRE

    Lily Riggs; McQuiggan, Douglas A.; Anderson, Adam K.; Ryan, Jennifer D.

    2010-01-01

    Research shows that memory for emotional aspects of an event may be enhanced at the cost of impaired memory for surrounding peripheral details. However, this has only been assessed directly via verbal reports which reveal the outcome of a long stream of processing but cannot shed light on how/when emotion may affect the retrieval process. In the present experiment, eye movement monitoring was used as an indirect measure of memory as it can reveal aspects of online memory processing. For ex...

  1. Eye Movement Monitoring Reveals Differential Influences of Emotion on Memory

    OpenAIRE

    Riggs, Lily; McQuiggan, Douglas A.; Anderson, Adam K.; Ryan, Jennifer D.

    2010-01-01

    Research shows that memory for emotional aspects of an event may be enhanced at the cost of impaired memory for surrounding peripheral details. However, this has only been assessed directly via verbal reports which reveal the outcome of a long stream of processing but cannot shed light on how/when emotion may affect the retrieval process. In the present experiment, eye movement monitoring (EMM) was used as an indirect measure of memory as it can reveal aspects of online memory processing. For...

  2. Secondary-Task Effects on Learning with Multimedia: An Investigation through Eye-Movement Analysis

    Science.gov (United States)

    Acarturk, Cengiz; Ozcelik, Erol

    2017-01-01

    This study investigates secondary-task interference on eye movements through learning with multimedia. We focus on the relationship between the influence of the secondary task on the eye movements of learners, and the learning outcomes as measured by retention, matching, and transfer. Half of the participants performed a spatial tapping task while…

  3. Suppression of Face Perception during Saccadic Eye Movements

    Directory of Open Access Journals (Sweden)

    Mehrdad Seirafi

    2014-01-01

    Full Text Available Lack of awareness of a stimulus briefly presented during saccadic eye movement is known as saccadic omission. Studying the reduced visibility of visual stimuli around the time of saccade—known as saccadic suppression—is a key step to investigate saccadic omission. To date, almost all studies have been focused on the reduced visibility of simple stimuli such as flashes and bars. The extension of the results from simple stimuli to more complex objects has been neglected. In two experimental tasks, we measured the subjective and objective awareness of a briefly presented face stimuli during saccadic eye movement. In the first task, we measured the subjective awareness of the visual stimuli and showed that in most of the trials there is no conscious awareness of the faces. In the second task, we measured objective sensitivity in a two-alternative forced choice (2AFC face detection task, which demonstrated chance-level performance. Here, we provide the first evidence of complete suppression of complex visual stimuli during the saccadic eye movement.

  4. Fixational eye movements predict visual sensitivity.

    Science.gov (United States)

    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.

  5. TMS pulses on the frontal eye fields break coupling between visuospatial attention and eye movements

    NARCIS (Netherlands)

    Neggers, S.F.W.; Huijbers, W.; Vrijlandt, C.M.; Vlaskamp, B.N.S.; Schutter, D.J.L.G.; Kenemans, J.L.

    2007-01-01

    While preparing a saccadic eye movement, visual processing of the saccade goal is prioritized. Here, we provide evidence that the frontal eye fields (FEFs) are responsible for this coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging ( fMRI)-guid

  6. Levels of processing and Eye Movements: A Stimulus driven approach

    DEFF Research Database (Denmark)

    Mulvey, Fiona Bríd

    2014-01-01

    . This series of studies attempts to provide explanatory information for previous findings that saccade amplitude and fixation duration are indicative of levels of processing and to isolate top down influences on eye movements with a stimulus driven approach. This approach involves developing measures suitable...... for studying individual differences in attention in large sample groups, using stimulus pairs which are similar in terms of bottom up properties but different in terms of higher level processing. These methods are presented in study 1, stimuli are developed and tested in Study 2. Study 3 uses these stimuli...... to investigate individual differences in levels of processing within the normal population using existing constructs and tests of cognitive style. Study 4 investigates these stimuli and the eye movements of a clinical group with known interruption to the dorsal stream of processing, and subsequent isolated...

  7. Eye movement desensitization and reprocessing (EMDR): a meta-analysis.

    Science.gov (United States)

    Davidson, P R; Parker, K C

    2001-04-01

    Eye movement desensitization and reprocessing (EMDR), a controversial treatment suggested for posttraumatic stress disorder (PTSD) and other conditions, was evaluated in a meta-analysis of 34 studies that examined EMDR with a variety of populations and measures. Process and outcome measures were examined separately. and EMDR showed an effect on both when compared with no treatment and with therapies not using exposure to anxiety-provoking stimuli and in pre post EMDR comparisons. However, no significant effect was found when EMDR was compared with other exposure techniques. No incremental effect of eye movements was noted when EMDR was compared with the same procedure without them. R. J. DeRubeis and P. Crits-Christoph (1998) noted that EMDR is a potentially effective treatment for noncombat PTSD. but studies that examined such patient groups did not give clear support to this. In sum, EMDR appears to be no more effective than other exposure techniques, and evidence suggests that the eye movements integral to the treatment, and to its name, are unnecessary.

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

    Science.gov (United States)

    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.

  9. Eye movement monitoring reveals differential influences of emotion on memory.

    Science.gov (United States)

    Riggs, Lily; McQuiggan, Douglas A; Anderson, Adam K; Ryan, Jennifer D

    2010-01-01

    Research shows that memory for emotional aspects of an event may be enhanced at the cost of impaired memory for surrounding peripheral details. However, this has only been assessed directly via verbal reports which reveal the outcome of a long stream of processing but cannot shed light on how/when emotion may affect the retrieval process. In the present experiment, eye movement monitoring (EMM) was used as an indirect measure of memory as it can reveal aspects of online memory processing. For example, do emotions modulate the nature of memory representations or the speed with which such memories can be accessed? Participants viewed central negative and neutral scenes surrounded by three neutral objects and after a brief delay, memory was assessed indirectly via EMM and then directly via verbal reports. Consistent with the previous literature, emotion enhanced central and impaired peripheral memory as indexed by eye movement scanning and verbal reports. This suggests that eye movement scanning may contribute and/or is related to conscious access of memory. However, the central/peripheral tradeoff effect was not observed in an early measure of eye movement behavior, i.e., participants were faster to orient to a critical region of change in the periphery irrespective of whether it was previously studied in a negative or neutral context. These findings demonstrate emotion's differential influences on different aspects of retrieval. In particular, emotion appears to affect the detail within, and/or the evaluation of, stored memory representations, but it may not affect the initial access to those representations.

  10. A study of artificial eyes for the measurement of precision in eye-trackers.

    Science.gov (United States)

    Wang, Dong; Mulvey, Fiona B; Pelz, Jeff B; Holmqvist, Kenneth

    2016-07-06

    The precision of an eye-tracker is critical to the correct identification of eye movements and their properties. To measure a system's precision, artificial eyes (AEs) are often used, to exclude eye movements influencing the measurements. A possible issue, however, is that it is virtually impossible to construct AEs with sufficient complexity to fully represent the human eye. To examine the consequences of this limitation, we tested currently used AEs from three manufacturers of eye-trackers and compared them to a more complex model, using 12 commercial eye-trackers. Because precision can be measured in various ways, we compared different metrics in the spatial domain and analyzed the power-spectral densities in the frequency domain. To assess how precision measurements compare in artificial and human eyes, we also measured precision using human recordings on the same eye-trackers. Our results show that the modified eye model presented can cope with all eye-trackers tested and acts as a promising candidate for further development of a set of AEs with varying pupil size and pupil-iris contrast. The spectral analysis of both the AE and human data revealed that human eye data have different frequencies that likely reflect the physiological characteristics of human eye movements. We also report the effects of sample selection methods for precision calculations. This study is part of the EMRA/COGAIN Eye Data Quality Standardization Project.

  11. Eye movements during listening reveal spontaneous grammatical processing

    Directory of Open Access Journals (Sweden)

    Stephanie eHuette

    2014-05-01

    Full Text Available 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 analogue representations of features such as movement, that could be a key perceptual component to grammatical comprehension.

  12. Language-driven anticipatory eye movements in virtual reality.

    Science.gov (United States)

    Eichert, Nicole; Peeters, David; Hagoort, Peter

    2017-08-08

    Predictive language processing is often studied by measuring eye movements as participants look at objects on a computer screen while they listen to spoken sentences. This variant of the visual-world paradigm has revealed that information encountered by a listener at a spoken verb can give rise to anticipatory eye movements to a target object, which is taken to indicate that people predict upcoming words. The ecological validity of such findings remains questionable, however, because these computer experiments used two-dimensional stimuli that were mere abstractions of real-world objects. Here we present a visual-world paradigm study in a three-dimensional (3-D) immersive virtual reality environment. Despite significant changes in the stimulus materials and the different mode of stimulus presentation, language-mediated anticipatory eye movements were still observed. These findings thus indicate that people do predict upcoming words during language comprehension in a more naturalistic setting where natural depth cues are preserved. Moreover, the results confirm the feasibility of using eyetracking in rich and multimodal 3-D virtual environments.

  13. Paroxysmal eye-head movements in Glut1 deficiency syndrome.

    Science.gov (United States)

    Pearson, Toni S; Pons, Roser; Engelstad, Kristin; Kane, Steven A; Goldberg, Michael E; De Vivo, Darryl C

    2017-04-25

    To describe a characteristic paroxysmal eye-head movement disorder that occurs in infants with Glut1 deficiency syndrome (Glut1 DS). We retrospectively reviewed the medical charts of 101 patients with Glut1 DS to obtain clinical data about episodic abnormal eye movements and analyzed video recordings of 18 eye movement episodes from 10 patients. A documented history of paroxysmal abnormal eye movements was found in 32/101 patients (32%), and a detailed description was available in 18 patients, presented here. Episodes started before age 6 months in 15/18 patients (83%), and preceded the onset of seizures in 10/16 patients (63%) who experienced both types of episodes. Eye movement episodes resolved, with or without treatment, by 6 years of age in 7/8 patients with documented long-term course. Episodes were brief (usually <5 minutes). Video analysis revealed that the eye movements were rapid, multidirectional, and often accompanied by a head movement in the same direction. Eye movements were separated by clear intervals of fixation, usually ranging from 200 to 800 ms. The movements were consistent with eye-head gaze saccades. These movements can be distinguished from opsoclonus by the presence of a clear intermovement fixation interval and the association of a same-direction head movement. Paroxysmal eye-head movements, for which we suggest the term aberrant gaze saccades, are an early symptom of Glut1 DS in infancy. Recognition of the episodes will facilitate prompt diagnosis of this treatable neurodevelopmental disorder. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  14. Eye Movement Trajectories and What They Tell Us

    NARCIS (Netherlands)

    Stigchel, van der S.

    2007-01-01

    The present thesis is concerned with how our eyes move trough space. Since the pioneering work of Yarbus it is known that the trajectories of the eyes can tell a great deal about the underlying cognitive processes. The current thesis is not just concerned with eye movement trajectories in general

  15. Measuring Facial Movement

    Science.gov (United States)

    Ekman, Paul; Friesen, Wallace V.

    1976-01-01

    The Facial Action Code (FAC) was derived from an analysis of the anatomical basis of facial movement. The development of the method is explained, contrasting it to other methods of measuring facial behavior. An example of how facial behavior is measured is provided, and ideas about research applications are discussed. (Author)

  16. CERN's eagle-eyed movement hunters in action

    CERN Multimedia

    2007-01-01

    Vibrations, movements, strains - nothing escapes the eagle eyes of CERN's Mechanical Measurements Laboratory, which helps groups needing mechanical testing and delicate transport operations. Graphical representation of the natural mode shape of one of the end-caps of the ATLAS inner detector, determined through experimentation.After installation of sensors on one of the end-caps of the ATLAS inner detector, CERN's Mechanical Measurements team performs remote checks to ensure the sensors are working properly before transport. They are on the look-out for anything that moves, shakes or changes shape. The slightest movement, however minute, will attract their attention. The Mechanical Measurements team, which is part of the Installation Coordination Group (TS-IC), specialises in all kinds of vibration studies, for design projects as well as for the transport of fragile objects. The Mechanical Measurements Laboratory was created in 1973 and, after a lull at the end of the century, was given a new lease of life ...

  17. Delayed saccadic eye movements in glaucoma

    Directory of Open Access Journals (Sweden)

    Kanjee R

    2012-11-01

    Full Text Available Raageen Kanjee,1 Yeni H Yücel,1,2 Martin J Steinbach,3,4 Esther G González,3,4 Neeru Gupta1,2,51Ophthalmology and Vision Sciences, Laboratory Medicine and Pathobiology, St Michael's Hospital, University of Toronto, 2Keenan Research Centre at the Li Ka Shing Knowledge Institute of St Michael's Hospital, 3Toronto Western Hospital, University Health Network, 4Centre for Vision Research, York University, 5Glaucoma and Nerve Protection Unit, St Michael's Hospital, Toronto, ON, CanadaPurpose: To determine whether saccadic eye movements are altered in glaucoma patients.Patients and methods: Sixteen patients with glaucoma and 21 control subjects were prospectively studied. Patients participated in a pro-saccade step task. Saccades were recorded using a noninvasive infrared oculometric device with head-mounted target projection. Medians of saccade reaction time, duration, amplitude, and peak velocity; frequency of express saccades; and percentage of trials with direction error were recorded. t-tests were used to compare the glaucoma and age-matched control groups. A correlation analysis of saccade parameters with visual field loss was also performed.Results: Median saccade reaction times were significantly prolonged in glaucoma patients compared with controls (220.9 ± 49.02 ms vs 192.1 ± 31.24 ms; t-test: P = 0.036. Median duration, median amplitude, and median peak velocity of saccades did not show significant differences between glaucoma and control groups (P > 0.05. Frequency of express saccades was significantly decreased in glaucoma patients compared with controls (1.75 ± 2.32 vs 7.0 ± 6.99; t-test: P = 0.007. Saccade parameters in glaucoma patients showed no significant correlation with visual field loss.Conclusion: Saccadic eye movements are significantly delayed in patients with early, moderate, or advanced glaucoma. Determination of median saccade reaction time may offer a novel functional test to quantify visual function in glaucoma

  18. The concurrent use of three implicit measures (eye movements, pupillometry, and event-related potentials) to assess receptive vocabulary knowledge in normal adults.

    Science.gov (United States)

    Ledoux, Kerry; Coderre, Emily; Bosley, Laura; Buz, Esteban; Gangopadhyay, Ishanti; Gordon, Barry

    2016-03-01

    Recent years have seen the advent and proliferation of the use of implicit techniques to study learning and cognition. One such application is the use of event-related potentials (ERPs) to assess receptive vocabulary knowledge. Other implicit assessment techniques that may be well-suited to other testing situations or to use with varied participant groups have not been used as widely to study receptive vocabulary knowledge. We sought to develop additional implicit techniques to study receptive vocabulary knowledge that could augment the knowledge gained from the use of the ERP technique. Specifically, we used a simple forced-choice paradigm to assess receptive vocabulary knowledge in normal adult participants using eye movement monitoring (EM) and pupillometry. In the same group of participants, we also used an N400 semantic incongruity ERP paradigm to assess their knowledge of two groups of words: those expected to be known to the participants (high-frequency, familiar words) and those expected to be unknown (low-frequency, unfamiliar words). All three measures showed reliable differences between the known and unknown words. EM and pupillometry thus may provide insight into receptive vocabulary knowledge similar to that from ERPs. The development of additional implicit assessment techniques may increase the feasibility of receptive vocabulary testing across a wider range of participant groups and testing situations, and may make the conduct of such testing more accessible to a wider range of researchers, clinicians, and educators.

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

    Science.gov (United States)

    Dooley, K O; Farmer, A

    1988-08-01

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

  20. Analyzing Head and Eye Movement System with CORBA

    OpenAIRE

    Wang Changyuan; Zhang Jing; Chen YuLong

    2013-01-01

    In order to study the vestibular system in different organs of movement as well as their collaboration between working mechanism, this paper designs a model of the common object request broker architecture (CORBA) for the head and eye movement system based on the vestibular function. By analyzing physiological characteristics of the head and eye movement model, and further introducing the structure features of CORBA. It focus on the component composition and the model design of CORBA compon...

  1. Forward models and state estimation in compensatory eye movements

    NARCIS (Netherlands)

    M.A. Frens (Maarten); O. Donchin (Opher)

    2009-01-01

    textabstractThe compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of the physiology of limb movements, we suggest that CEM can be modeled as a control system w

  2. Forward models and state estimation in compensatory eye movements

    NARCIS (Netherlands)

    M.A. Frens (Maarten); O. Donchin (Opher)

    2009-01-01

    textabstractThe compensatory eye movement (CEM) system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of the physiology of limb movements, we suggest that CEM can be modeled as a control system

  3. MODELLING SYNERGISTIC EYE MOVEMENTS IN THE VISUAL FIELD

    Directory of Open Access Journals (Sweden)

    BARITZ Mihaela

    2015-06-01

    Full Text Available Some theoretical and practical considerations about eye movements in visual field are presented in the first part of this paper. These movements are developed into human body to be synergistic and are allowed to obtain the visual perception in 3D space. The theoretical background of the eye movements’ analysis is founded on the establishment of movement equations of the eyeball, as they consider it a solid body with a fixed point. The exterior actions, the order and execution of the movements are ensured by the neural and muscular external system and thus the position, stability and movements of the eye can be quantified through the method of reverse kinematic. The purpose of these researches is the development of a simulation model of human binocular visual system, an acquisition methodology and an experimental setup for data processing and recording regarding the eye movements, presented in the second part of the paper. The modeling system of ocular movements aims to establish the binocular synergy and limits of visual field changes in condition of ocular motor dysfunctions. By biomechanical movements of eyeball is established a modeling strategy for different sort of processes parameters like convergence, fixation and eye lens accommodation to obtain responses from binocular balance. The results of modelling processes and the positions of eye ball and axis in visual field are presented in the final part of the paper.

  4. The effect of glare on eye movements when reading.

    Science.gov (United States)

    Glimne, S; Brautaset, R L; Seimyr, G Öqvist

    2015-01-01

    Glare is a very common source of image degradation when performing computer work. Since reading is a task that is very sensitive to image degradation induced disability glare affects reading performance. To assess the effect of different glare conditions on eye movements when reading on a computer screen. Glare conditions have an impact on reading. This observation is based on the results from a study where we investigated how reading eye movements were affected by glare. Sixteen subjects with normal vision participated in this study. In a balanced repeated-measurement study, all subjects performed equal near-vision reading tasks. In addition to the condition of no glare three controlled conditions of glare were used: direct light, indirect light, and desk luminary. The subjects read three texts under each condition: First a short standardized text (IReST), secondly a longer newspaper text, and finally an additional IReST text. The texts were read on a Tobii T120 eye tracker. The results show that glare does have a negative effect on reading performance. The more adverse the lighting condition was, the slower the reading speed became. The decrease was primarily a result of increased fixation durations. Both glare conditions of direct and indirect glare increased the fixation durations significantly (p < 0.05). This study shows that even moderate glare conditions can have an impact on reading. The results show that it is important to follow recommendations of lighting design in computer work environment in order to avoid disability glare.

  5. Head movement compensation and multi-modal event detection in eye-tracking data for unconstrained head movements.

    Science.gov (United States)

    Larsson, Linnéa; Schwaller, Andrea; Nyström, Marcus; Stridh, Martin

    2016-12-01

    The complexity of analyzing eye-tracking signals increases as eye-trackers become more mobile. The signals from a mobile eye-tracker are recorded in relation to the head coordinate system and when the head and body move, the recorded eye-tracking signal is influenced by these movements, which render the subsequent event detection difficult. The purpose of the present paper is to develop a method that performs robust event detection in signals recorded using a mobile eye-tracker. The proposed method performs compensation of head movements recorded using an inertial measurement unit and employs a multi-modal event detection algorithm. The event detection algorithm is based on the head compensated eye-tracking signal combined with information about detected objects extracted from the scene camera of the mobile eye-tracker. The method is evaluated when participants are seated 2.6m in front of a big screen, and is therefore only valid for distant targets. The proposed method for head compensation decreases the standard deviation during intervals of fixations from 8° to 3.3° for eye-tracking signals recorded during large head movements. The multi-modal event detection algorithm outperforms both an existing algorithm (I-VDT) and the built-in-algorithm of the mobile eye-tracker with an average balanced accuracy, calculated over all types of eye movements, of 0.90, compared to 0.85 and 0.75, respectively for the compared algorithms. The proposed event detector that combines head movement compensation and information regarding detected objects in the scene video enables for improved classification of events in mobile eye-tracking data. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Eye Movement Impairment Recovery in a Gaucher Patient Treated with Miglustat

    Directory of Open Access Journals (Sweden)

    Agostino Accardo

    2010-01-01

    Two sisters, presenting the same genotype (R353G/R353G, were diagnosed as suffering from GD; one of them later developed neurological alterations identified by quantitative saccadic eye movements analysis. The aim of the study was to quantitatively measure the miglustat effects in this GD neurological patient. Eye movement analysis during subsequent controls was performed by estimating the characteristic parameters of saccadic main sequence. The study demonstrates that the SRT alone can be effective in GD3. Moreover, it confirms that quantitative eye movement analysis is able to precociously identify also slight neurological alterations, permitting more accurate GD classification.

  7. P1-26: Influence of Depth from Luminance Contrast on Vergence Eye Movements

    Directory of Open Access Journals (Sweden)

    Akinori Hiratani

    2012-10-01

    Full Text Available A vergence eye movement is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision. It has been shown that a vergence movement is induced not only by binocular depth but also by the changing size of the stimuli, which produces perception of motion in depth. That is, a monocular depth cue influences the direction of the eye movement, even when the eye movement contradicts depth from the disparity cue. Despite that a number of monocular depth cues are known, the influence on the vergence movement is known only with changing size. In this study, we focused on luminance contrast as a monocular depth cue and examined whether it influences the vergence movement. The stimuli were a Gabor patch with contrast changing sinusoidally in time at a given temporal frequency. When the observer looks at the stimuli, apparent depth changes with the contrast change. Eye movement measurements showed vergence movements synchronizing with luminance changes. Change in perceived depth caused by change of the luminance contrast influences vergence movement.

  8. Optimal Control of the Compensatory Eye Movement System

    NARCIS (Netherlands)

    T.M. Sibindi (Tafadzwa)

    2015-01-01

    markdownabstractIn this thesis, we utilized behavioural, electrophysiological, computational and stimulation techniques to delve our knowledge further into the functional neural network of the compensatory eye movement system (CEM). We first investigated the superposition violations and non-lineari

  9. Understanding eye movements in face recognition using hidden Markov models.

    Science.gov (United States)

    Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

    2014-09-16

    We use a hidden Markov model (HMM) based approach to analyze eye movement data in face recognition. HMMs are statistical models that are specialized in handling time-series data. We conducted a face recognition task with Asian participants, and model each participant's eye movement pattern with an HMM, which summarized the participant's scan paths in face recognition with both regions of interest and the transition probabilities among them. By clustering these HMMs, we showed that participants' eye movements could be categorized into holistic or analytic patterns, demonstrating significant individual differences even within the same culture. Participants with the analytic pattern had longer response times, but did not differ significantly in recognition accuracy from those with the holistic pattern. We also found that correct and wrong recognitions were associated with distinctive eye movement patterns; the difference between the two patterns lies in the transitions rather than locations of the fixations alone.

  10. The relationship between eye movement and vision develops before birth

    OpenAIRE

    Veronika eSchöpf; Thomas eSchlegl; Andras eJakab; Gregor eKasprian; Ramona eWoitek; Daniela ePrayer; Georg eLangs

    2014-01-01

    While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks.BOLD re...

  11. Eye Movements in Reading as Rational Behavior

    Science.gov (United States)

    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…

  12. The effect of cataract on eye movement perimetry

    NARCIS (Netherlands)

    G. Thepass; J.J.M. Pel (Johan); K.A. Vermeer (Koen); O. Creten; S. Bryan (Stirling); H.G. Lemij (Hans); J. van der Steen (Hans)

    2015-01-01

    textabstractPurpose. To determine how different grades of cataract affect sensitivity threshold and saccadic reaction time (SRT) in eye movement perimetry (EMP). Methods. In EMP, the visual field is tested by assessing the saccades that a subject makes towards peripheral stimuli using an eye

  13. Eye movement and pupil size constriction under discomfort glare.

    Science.gov (United States)

    Lin, Yandan; Fotios, Steve; Wei, Minchen; Liu, Yihong; Guo, Weihong; Sun, Yaojie

    2015-01-29

    Involuntary physiological responses offer an alternative means to psychophysical procedures for objectively evaluating discomfort glare. This study examined eye movement and pupil size responses to glare discomfort using new approaches to analysis: relative pupil size and speed of eye movement. Participants evaluated glare discomfort using the standard de Boer rating scale under various conditions manipulated to influence glare discomfort. Eye movement was recorded using an electro-oculogram (EOG), and pupil size was recorded using Tobii glasses. Ten young (mean age: 24.5 years old) and 10 senior (mean age: 61 years old) participants were recruited for this experiment. Subjective evaluation of glare discomfort was highly correlated with eye movement (multiple correlation coefficient [R(2)] of >0.94, P < 0.001) and pupil constriction (R(2) = 0.38, P < 0.001). Severe glare discomfort increased the speed of eye movement and caused larger pupil constriction. Larger variations of eye movement were found among seniors. The two physiological responses studied here to characterize discomfort glare under various lighting conditions had significant correlation with the subjective evaluation. The correlation between discomfort glare and physiological responses suggests an objective way to characterize and evaluate discomfort glare that may overcome the problems of conventional subjective evaluation. It also offers an explanation as to why long-term exposure to discomfort glare leads to visual fatigue and eyestrain. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  14. Eye tracking a comprehensive guide to methods and measures

    CERN Document Server

    Holmqvist, Kenneth; Andersson, Richard; Dewhurst, Richard; Jarodzka, Halszka; Weijer, Joost van de

    2011-01-01

    We make 3-5 eye movements per second, and these movements are crucial in helping us deal with the vast amounts of information we encounter in our everyday lives. In recent years, thanks to the development of eye tracking technology, there has been a growing interest in monitoring and measuring these movements, with a view to understanding how we attend to and process the visual information we encounter Eye tracking as a research tool is now more accessible than ever, and is growing in popularity amongst researchers from a whole host of different disciplines. Usability analysts, sports scientists, cognitive psychologists, reading researchers, psycholinguists, neurophysiologists, electrical engineers, and others, all have a vested interest in eye tracking for different reasons. The ability to record eye-movements has helped advance our science and led to technological innovations. However, the growth of eye tracking in recent years has also presented a variety of challenges - in particular the issue of how to d...

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

    Science.gov (United States)

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

    2015-04-15

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

  16. Recording three-dimensional eye movements: scleral search coils versus video-oculography

    NARCIS (Netherlands)

    Houben, M.M.J.; Goumans, J.; Steen, J. van der

    2006-01-01

    PURPOSE. This study compared the performance of a videobased infrared three-dimensional eye tracker device (Chronos) with the scleral search coil method. METHODS. Three-dimensional eye movements were measured simultaneously with both systems during fixation, saccades, optokinetic stimulation, and ve

  17. Retinal image smear as a source of information about magnitude of eye movement.

    Science.gov (United States)

    Festinger, L; Holtzman, J D

    1978-11-01

    A number of experiments were conducted to determine to what extent retinal image smearing during saccades provides information about the eye movement magnitude to the perceptual system. The technique involved obtaining measures of perceived movement when the total visual field was displaced in conjunction with saccadic eye movements. Trials with normal retinal smear were compared with trials on which smearing was greatly reduced or eliminated. The results are interpreted as showing that the absence of normal retinal smear during a saccade increases the uncertainty in the information available to the perceptual system and that this uncertainty results in a tendency to perceive smaller than veridical amounts of movement.

  18. Rate of entrance of benzodiazepines into the brain determined by eye movement recording.

    OpenAIRE

    1983-01-01

    1 Peak saccadic velocity of horizontal eye movements, saccade duration at 30 degrees of amplitude and saccade reaction time were measured in six drug free male subjects. 2 In two separate experiments, intravenous doses of diazepam (5 mg), lorazepam (2 mg), chlordiazepoxide (25 mg) and placebo were given, and eye movement recordings were made before and at frequent intervals after drug administration. 3 All the benzodiazepines produced a significant impairment of peak saccadic velocity and sac...

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

    DEFF Research Database (Denmark)

    Dauvilliers, Yves; Jennum, Poul; Plazzi, Giuseppe

    2013-01-01

    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...... 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...

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

    Directory of Open Access Journals (Sweden)

    Kevin van Schie

    2016-07-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  2. Efficient Avoidance of the Penalty Zone in Human Eye Movements

    Science.gov (United States)

    Theeuwes, Jan

    2016-01-01

    People use eye movements extremely effectively to find objects of interest in a cluttered visual scene. Distracting, task-irrelevant attention capturing regions in the visual field should be avoided as they jeopardize the efficiency of search. In the current study, we used eye tracking to determine whether people are able to avoid making saccades to a predetermined visual area associated with a financial penalty, while making fast and accurate saccades towards stimuli placed near the penalty area. We found that in comparison to the same task without a penalty area, the introduction of a penalty area immediately affected eye movement behaviour: the proportion of saccades to the penalty area was immediately reduced. Also, saccadic latencies increased, but quite modestly, and mainly for saccades towards stimuli near the penalty area. We conclude that eye movement behaviour is under efficient cognitive control and thus quite flexible: it can immediately be adapted to changing environmental conditions to improve reward outcome. PMID:27930724

  3. [Systematic deviations of saccadic eye movements in Wallenberg syndrome].

    Science.gov (United States)

    Hamann, K U

    1979-01-01

    A patient suffering from lateral medullary infarction (Wallenberg's syndrome) is presented, exhibiting a striking bias of all saccadic eye movements toward the side of the lesion. Oculographic tracings demonstrate this oculomotor disorder. Other disturbances of ocular motility which resemble this one superficially are discussed. Interruption of fixation leads to a gliding movement veeringly to the side of the infarction. Since all saccades generated under different circumstances are affected, it is contemplated where the pathological signal is intruded into the prenuclear level, to adulterate all saccades causing lateropulsion of saccadic eye movements.

  4. Eye movements reveal epistemic curiosity in human observers.

    Science.gov (United States)

    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.

  5. Smooth pursuit eye movements and schizophrenia: literature review.

    Science.gov (United States)

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

    2014-09-01

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

  6. Eye Movement Desensitization and Reprocessing (EMDR as a Neurorehabilitation Method

    Directory of Open Access Journals (Sweden)

    Afsaneh Zarghi

    2013-01-01

    Full Text Available   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.

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

    Directory of Open Access Journals (Sweden)

    Mo Weike

    2010-09-01

    Full Text Available Abstract 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.

  8. Estimation of mental workload using saccadic eye movements in a free-viewing task.

    Science.gov (United States)

    Tokuda, Satoru; Obinata, Goro; Palmer, Evan; Chaparro, Alex

    2011-01-01

    This study proposes a new method to automatically estimate a person's mental workload (MWL) using a specific type of eye movements called saccadic intrusions (SI). Previously, the most accurate existing method to estimate MWL was the pupil diameter measure [1]. However, pupil diameter is not practical in a vehicle driving environment because it is overly sensitive to brightness changes. A new method should be independent from environment brightness changes, robust in most driving environments, and accurately reflect MWL. This study used SI as an indicator of MWL because eye movements, including SI, are independent from brightness changes. SI are a specific type of eye-gaze deviations. SI are known to be closely related to cognitive activities [2], [3]. This means that SI may be also closely related to MWL. Eye movements were recorded using a non-intrusive eye tracking camera, located 550 mm away from a participant. Participants were instructed to move their eye gaze to examine a highway driving scenery picture. In the data set of the recorded eye movements, our new algorithm detected SI and quantified SI behavior into a SI measure. Participants were also engaged in a secondary N-back task. The N-back task is a popular task used in cognitive sciences to systematically control a MWL level of participants. In our results, all 14 participants exhibited more SI eye movements when their MWL level was high compared to when their MWL level was low. Moreover, our results showed that the SI measure was a more accurate measure of MWL than the pupil diameter measure. This finding indicates that MWL of the person can be estimated by observation of SI eye movements. This new method has a wide range of applications. One of them is to predict a person's MWL, thus predicting when a person is capable of driving a vehicle in a safe or dangerous manner.

  9. Non-intrusive eye gaze tracking under natural head movements.

    Science.gov (United States)

    Kim, S; Sked, M; Ji, Q

    2004-01-01

    We propose an eye gaze tracking system under natural head movements. The system consists of one CCD camera and two mirrors. Based on geometric and linear algebra calculations, the mirrors rotate to follow head movements in order to keep the eyes within the view of the camera. Our system allows the subjects head to move 30 cm horizontally and 20 cm vertically, with spatial gaze resolutions about 6 degree and 7 degree, respectively and a frame rate about 10 Hz. We also introduce a hierarchical generalized regression neural networks (H-GRNN) scheme to map eye and mirror parameters to gaze, achieving a gaze estimation accuracy of 92% under head movements. The use of H-GRNN also eliminates the need for personal calibration for new subjects since H-GRNN can generalize. Preliminary experiments show our system is accurate and robust in gaze tracking under large head movements.

  10. Does consolidation of visuospatial sequence knowledge depend on eye movements?

    Science.gov (United States)

    Coomans, Daphné; Vandenbossche, Jochen; Homblé, Koen; Van den Bussche, Eva; Soetens, Eric; Deroost, Natacha

    2014-01-01

    In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT) task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM) condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM) condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  11. Does consolidation of visuospatial sequence knowledge depend on eye movements?

    Directory of Open Access Journals (Sweden)

    Daphné Coomans

    Full Text Available In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  12. Large pupils predict goal-driven eye movements.

    Science.gov (United States)

    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. (c) 2015 APA, all rights reserved).

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

    Science.gov (United States)

    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.

  14. Macular degeneration affects eye movement behaviour during visual search

    Directory of Open Access Journals (Sweden)

    Stefan eVan Der Stigchel

    2013-09-01

    Full Text Available Patients with a scotoma in their central vision (e.g. due to macular degeneration, MD commonly adopt a strategy to direct the eyes such that the image falls onto a peripheral location on the retina. This location is referred to as the preferred retinal locus (PRL. Although previous research has investigated the characteristics of this PRL, it is unclear whether eye movement metrics are modulated by peripheral viewing with a PRL as measured during a visual search paradigm. To this end, we tested four MD patients in a visual search paradigm and contrasted their performance with a healthy control group and a healthy control group performing the same experiment with a simulated scotoma. The experiment contained two conditions. In the first condition the target was an unfilled circle hidden among c-shaped distractors (serial condition and in the second condition the target was a filled circle (pop-out condition. Saccadic search latencies for the MD group were significantly longer in both conditions compared to both control groups. Results of a subsequent experiment indicated that this difference between the MD and the control groups could not be explained by a difference in target selection sensitivity. Furthermore, search behaviour of MD patients was associated with saccades with smaller amplitudes towards the scotoma, an increased intersaccadic interval and an increased number of eye movements necessary to locate the target. Some of these characteristics, such as the increased intersaccadic interval, were also observed in the simulation group, which indicate that these characteristics are related to the peripheral viewing itself. We suggest that the combination of the central scotoma and peripheral viewing can explain the altered search behaviour and no behavioural evidence was found for a possible reorganization of the visual system associated with the use of a PRL. Thus the switch from a fovea-based to a PRL-based reference frame impairs search

  15. Fixational eye movements in the earliest stage of metazoan evolution.

    Directory of Open Access Journals (Sweden)

    Jan Bielecki

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

  16. Hawk eyes I: diurnal raptors differ in visual fields and degree of eye movement.

    Directory of Open Access Journals (Sweden)

    Colleen T O'Rourke

    Full Text Available 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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Inverting faces does not abolish cultural diversity in eye movements.

    Science.gov (United States)

    Rodger, Helen; Kelly, David J; Blais, Caroline; Caldara, Roberto

    2010-01-01

    Face processing is widely understood to be a basic, universal visual function effortlessly achieved by people from all cultures and races. The remarkable recognition performance for faces is markedly and specifically affected by picture-plane inversion: the so-called face-inversion effect (FIE), a finding often used as evidence for face-specific mechanisms. However, it has recently been shown that culture shapes the way people deploy eye movements to extract information from faces. Interestingly, the comparable lack of experience with inverted faces across cultures offers a unique opportunity to establish the extent to which such cultural perceptual biases in eye movements are robust, but also to assess whether face-specific mechanisms are universally tuned. Here we monitored the eye movements of Western Caucasian (WC) and East Asian (EA) observers while they learned and recognised WC and EA inverted faces. Both groups of observers showed a comparable impairment in recognising inverted faces of both races. WC observers deployed a scattered inverted triangular scanpath with a bias towards the mouth, whereas EA observers uniformly extended the focus of their fixations from the centre towards the eyes. Overall, our data show that cultural perceptual differences in eye movements persist during the FIE, questioning the universality of face-processing mechanisms.

  20. Eye movement analysis for activity recognition using electrooculography.

    Science.gov (United States)

    Bulling, Andreas; Ward, Jamie A; Gellersen, Hans; Tröster, Gerhard

    2011-04-01

    In this work, we investigate eye movement analysis as a new sensing modality for activity recognition. Eye movement data were recorded using an electrooculography (EOG) system. We first describe and evaluate algorithms for detecting three eye movement characteristics from EOG signals-saccades, fixations, and blinks-and propose a method for assessing repetitive patterns of eye movements. We then devise 90 different features based on these characteristics and select a subset of them using minimum redundancy maximum relevance (mRMR) feature selection. We validate the method using an eight participant study in an office environment using an example set of five activity classes: copying a text, reading a printed paper, taking handwritten notes, watching a video, and browsing the Web. We also include periods with no specific activity (the NULL class). Using a support vector machine (SVM) classifier and person-independent (leave-one-person-out) training, we obtain an average precision of 76.1 percent and recall of 70.5 percent over all classes and participants. The work demonstrates the promise of eye-based activity recognition (EAR) and opens up discussion on the wider applicability of EAR to other activities that are difficult, or even impossible, to detect using common sensing modalities.

  1. Functional neuroanatomical correlates of eye movements during rapid eye movement sleep in depressed patients.

    Science.gov (United States)

    Germain, Anne; Buysse, Daniel J; Wood, Annette; Nofzinger, Eric

    2004-04-30

    In depressed patients, REM density, or the number of rapid eye movements (REMs) per minute of REM sleep, is a correlate of depression severity and clinical outcomes. We investigated the functional neuroanatomical correlates of average REM counts (RC), an automated analog of REM density, in depression. Thirteen medication-free depressed patients underwent all night polysomnography and positron emission tomography (PET) scans using [(18)F]fluoro-2-deoxy-d-glucose ([(18)F] FDG) during REM sleep. Regression analyses were conducted with Statistical Parametric Mapping (SPM-99). Average RC significantly and positively correlated with relative regional cerebral metabolic rate of glucose (rCMRglc) bilaterally in the striate cortex, the posterior parietal cortices, and in the medial and ventrolateral prefrontal cortices. Average RC were negatively correlated with rCMRglc in areas corresponding bilaterally to the lateral occipital cortex, cuneus, temporal cortices, and parahippocampal gyri. The areas where average RC was positively correlated with rCMRglc appear to constitute a diffuse cortical system involved in the regulation of emotion-induced arousal. The observed pattern of correlations suggests that average RC may be a marker of hypofrontality during REM sleep in depressed patients.

  2. Rapid Eye Movement Sleep Behavior Disorder and Other Rapid Eye Movement Sleep Parasomnias.

    Science.gov (United States)

    Högl, Birgit; Iranzo, Alex

    2017-08-01

    The most common rapid eye movement (REM) parasomnia encountered by neurologists is REM sleep behavior disorder (RBD), and nightmares are so frequent that every neurologist should be able to differentiate them from the dream enactment of RBD. Isolated sleep paralysis is relatively common and is often mistaken for other neurologic disorders. This article summarizes the current state of the art in the diagnosis of RBD, discusses the role of specific questionnaires and polysomnography in the diagnosis of RBD, and reviews recent studies on idiopathic RBD as an early feature of a synucleinopathy, secondary RBD, and its management. Recent diagnostic criteria and implications of nightmares and isolated sleep paralysis are also reviewed. Idiopathic RBD can now be considered as part of the prodromal stage of a synucleinopathy. Therefore, an accurate diagnosis is mandatory, and this implies detection of REM sleep without atonia. The polysomnography montage, including EMG of the submentalis and flexor digitorum superficialis muscles, provides a high sensitivity and specificity for the diagnosis. The exact diagnosis is important for patient counseling and for future neuroprotective trials. REM parasomnias include RBD, sleep paralysis, and nightmares, which have distinct clinical characteristics and different implications regarding diagnostic procedures, management, and prognosis.

  3. Central crosstalk for somatic tinnitus: abnormal vergence eye movements.

    Directory of Open Access Journals (Sweden)

    Qing Yang

    Full Text Available BACKGROUND: Frequent oulomotricity problems with orthoptic testing were reported in patients with tinnitus. This study examines with objective recordings vergence eye movements in patients with somatic tinnitus patients with ability to modify their subjective tinnitus percept by various movements, such as jaw, neck, eye movements or skin pressure. METHODS: Vergence eye movements were recorded with the Eyelink II video system in 15 (23-63 years control adults and 19 (36-62 years subjects with somatic tinnitus. FINDINGS: 1 Accuracy of divergence but not of convergence was lower in subjects with somatic tinnitus than in control subjects. 2 Vergence duration was longer and peak velocity was lower in subjects with somatic tinnitus than in control subjects. 3 The number of embedded saccades and the amplitude of saccades coinciding with the peak velocity of vergence were higher for tinnitus subjects. Yet, saccades did not increase peak velocity of vergence for tinnitus subjects, but they did so for controls. 4 In contrast, there was no significant difference of vergence latency between these two groups. INTERPRETATION: The results suggest dysfunction of vergence areas involving cortical-brainstem-cerebellar circuits. We hypothesize that central auditory dysfunction related to tinnitus percept could trigger mild cerebellar-brainstem dysfunction or that tinnitus and vergence dysfunction could both be manifestations of mild cortical-brainstem-cerebellar syndrome reflecting abnormal cross-modality interactions between vergence eye movements and auditory signals.

  4. Head and eye movement as pointing modalities for eyewear computers

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako; Pederson, Thomas

    2014-01-01

    While the new generation of eyewear computers have increased expectations of a wearable computer, providing input to these devices is still challenging. Hand-held devices, voice commands, and hand gestures have already been explored to provide input to the wearable devices. In this paper, we...... examined using head and eye movements to point on a graphical user interface of a wearable computer. The performance of users in head and eye pointing has been compared with mouse pointing as a baseline method. The result of our experiment showed that the eye pointing is significantly faster than head...

  5. Head and eye movement as pointing modalities for eyewear computers

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako; Pederson, Thomas

    2014-01-01

    While the new generation of eyewear computers have increased expectations of a wearable computer, providing input to these devices is still challenging. Hand-held devices, voice commands, and hand gestures have already been explored to provide input to the wearable devices. In this paper, we...... examined using head and eye movements to point on a graphical user interface of a wearable computer. The performance of users in head and eye pointing has been compared with mouse pointing as a baseline method. The result of our experiment showed that the eye pointing is significantly faster than head...

  6. Minimal dynamical description of eye movements

    Science.gov (United States)

    Specht, Juan I.; Dimieri, Leonardo; Urdapilleta, Eugenio; Gasaneo, Gustavo

    2017-02-01

    In this paper we have addressed the question of whether a simple set of functions being the solution of a model, namely the damped harmonic oscillator with a general driving force, can satisfactorily describe data corresponding to ocular movements produced during a visual search task. Taking advantage of its mathematical tractability, we first focused on the simplest driving force compatible to the experimental data, a step-like activation. Under this hypothesis we were able to further simplify the system, once data from several experiments were fitted, producing an essentially parameter-free model that we plan to use in future applications. To increase the quality of the description of individual movements, we expanded the complexity in the forcing term and solved the inverse problem by using a proper mathematical formalism. Furthermore, additional terms, those arising from ocular drift and tremor, may be included within the same mathematical approach.

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

    Science.gov (United States)

    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.

  8. Eye-movement patterns are associated with communicative competence in autistic spectrum disorders.

    Science.gov (United States)

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

    2009-07-01

    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. The eye-movements of 28 teenagers with ASD and 18 typically developing peers were recorded as they watched videos of peers interacting in familiar situations. Within ASD, we contrasted the viewing patterns of those with and without language impairments. The proportion of time spent viewing eyes, mouths and other scene details was calculated, as was latency of first fixation to eyes. Finally, the association between viewing patterns and social-communicative competence was measured. Individuals with ASD and age-appropriate language abilities spent significantly less time viewing eyes and were slower to fixate the eyes than typically developing peers. In contrast, there were no differences in viewing patterns between those with language impairments and typically developing peers. Eye-movement patterns were not associated with social outcomes for either language phenotype. However, increased fixations to the mouth were associated with greater communicative competence across the autistic spectrum. Attention to both eyes and mouths is important for language development and communicative competence. Differences in fixation time to eyes may not be sufficient to disrupt social competence in daily interactions. A multiple cognitive deficit model of ASD, incorporating different language phenotypes, is advocated.

  9. Eye movements characteristics of Chinese dyslexic children in picture searching

    Institute of Scientific and Technical Information of China (English)

    HUANG Xu; JING Jin; ZOU Xiao-bing; WANG Meng-long; LI Xiu-hong; LIN Ai-hua

    2008-01-01

    Background Reading Chinese,a kind of ideogram,relies more on visual cognition.The visuospatial cognitive deficit of Chinese dyslexia is an interesting topic that has received much attention.The purpose of current research was to explore the visuopatial cognitive characteristics of Chinese dyslexic children by studying their eye movements via a picture searching test.Methods According to the diagnostic criteria defined by ICD-10,twenty-eight dyslexic children (mean age (10.12+1.42)years) were enrolled from the Clinic of Children Behavioral Disorder in the third affiliated hospital of Sun Yat-sen University.And 28 normally reading children (mean age (10.06±1.29) years),1:1 matched by age,sex,grade and family condition were chosen from an elementary school in Guangzhou as a control group.Four groups of pictures (cock,accident,canyon,meditate) from Picture Vocabulary Test were chosen as eye movement experiment targets.All the subjects carried out the picture searching task and their eye movement data were recorded by an Eyelink Ⅱ High-Speed Eye Tracker.The duration time,average fixation duration,average saccade amplitude,fixation counts and saccade counts were compared between the two groups of children.Results The dyslexic children had longer total fixation duration and average fixation duration (F=7.711,P<0.01;F=4.520,P<0.05),more fixation counts and saccade counts (F=7.498,P<0.01;F=11.040,P<0.01),and a smaller average saccade amplitude (F=29.743,P<0.01) compared with controls.But their performance in the picture vocabulary test was the same as those of the control group.The eye movement indexes were affected by the difficulty of the pictures and words,all eye movement indexes,except saccade amplitude,had a significant difference within groups (P<0.05).Conclusions Chinese dyslexic children have abnormal eye movements in picture searching,applying slow fixations,more fixations and small and frequent saccades.Their abnormal eye movement mode reflects the

  10. Culture shapes eye movements for visually homogeneous objects

    Directory of Open Access Journals (Sweden)

    David J Kelly

    2010-04-01

    Full Text Available Culture affects the way people move their eyes to extract information in their visual world. Adults from Eastern societies (e.g., China display a disposition to process information holistically, whereas individuals from Western societies (e.g., Britain process information analytically. In terms of face processing, adults from Western cultures typically fixate the eyes and mouth, while adults from Eastern cultures fixate centrally on the nose region, yet face recognition accuracy is comparable across populations. A potential explanation for the observed differences relates to social norms concerning eye gaze avoidance/engagement when interacting with conspecifics. Furthermore, it has been argued that faces represent a ‘special’ stimulus category and are processed holistically, with the whole face processed as a single unit. The extent to which the holistic eye movement strategy deployed by East Asian observers is related to holistic processing for faces is undetermined. To investigate these hypotheses, we recorded eye movements of adults from Western and Eastern cultural backgrounds while learning and recognizing visually homogeneous objects: human faces, sheep faces and greebles. Both group of observers recognized faces better than any other visual category, as predicted by the specificity of faces. However, East Asian participants deployed central fixations across all the visual categories. This cultural perceptual strategy was not specific to faces, discarding any parallel between the eye movements of Easterners with the holistic processing specific to faces. Cultural diversity in the eye movements used to extract information from visual homogenous objects is rooted in more general and fundamental mechanisms.

  11. Forward models and state estimation in compensatory eye movements

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    Maarten A Frens

    2009-11-01

    Full Text Available The compensatory eye movement system maintains a stable retinal image, integrating information from different sensory modalities to compensate for head movements. Inspired by recent models of physiology of limb movements, we suggest that compensatory eye movements (CEM can be modeled as a control system with three essential building blocks: a forward model that predicts the effects of motor commands; a state estimator that integrates sensory feedback into this prediction; and, a feedback controller that translates a state estimate into motor commands. We propose a specific mapping of nuclei within the CEM system onto these control functions. Specifically, we suggest that the Flocculus is responsible for generating the forward model prediction and that the Vestibular Nuclei integrate sensory feedback to generate an estimate of current state. Finally, the brainstem motor nuclei – in the case of horizontal compensation this means the Abducens Nucleus and the Nucleus Prepositus Hypoglossi – implement a feedback controller, translating state into motor commands. While these efforts to understand the physiological control system as a feedback control system are in their infancy, there is the intriguing possibility that compensatory eye movements and targeted voluntary movements use the same cerebellar circuitry in fundamentally different ways.

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

    Science.gov (United States)

    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

  13. Phenothiazine effects on cerebral-evoked potentials and eye movements in acute schizophrenics.

    Science.gov (United States)

    Rappaport, M; Hopkins, H K; Hall, K; Belleza, T

    1975-01-01

    An investigation was made of the effects of phenothiazine medication on the averaged visual-evoked potentials (AVEP) and on eye movements in hospitalized, young, acute schizophrenic patients. These results were compared with those of normal subjects who were not given medication. AVEP measures included maximum amplitude (Am), frequency of peaks (FOP'S), variability (V) and peak latencies for an early negative peak (N1) and a later positive peak (P6). Eye movement measures included percent of time looking at a stimulus slide, percent of time looking at a figure on the slide, the number of fixations and the percent of cells entered in which fixations occurred. For schizophrenics off and on phenothiazine medication, there were no consistently significant drug effects on any measure except frequency of peaks. Schizophrenics compared to normals had lower amplitudes, greater frequency of peaks, greater variability and lower eye movement scores.

  14. Covert anti-compensatory quick eye movements during head impulses.

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    Maria Heuberger

    Full Text Available 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.

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

    Science.gov (United States)

    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…

  16. Morbidities in rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

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

    2013-01-01

    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 al...

  17. Vowel Processing During Silent Reading: Evidence from Eye Movements

    Science.gov (United States)

    Ashby, Jane; Treiman, Rebecca; Kessler, Brett; Rayner, Keith

    2006-01-01

    Two eye movement experiments examined whether skilled readers include vowels in the early phonological representations used in word recognition during silent reading. Target words were presented in sentences preceded by parafoveal previews in which the vowel phoneme was concordant or discordant with the vowel phoneme in the target word. In…

  18. Individual differences in impulsivity predict anticipatory eye movements.

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    Laetitia Cirilli

    Full Text Available 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.

  19. Eye Movement Analysis of Information Processing under Different Testing Conditions.

    Science.gov (United States)

    Dillon, Ronna F.

    1985-01-01

    Undergraduates were given complex figural analogies items, and eye movements were observed under three types of feedback: (1) elaborate feedback; (2) subjects verbalized their thinking and application of rules; and (3) no feedback. Both feedback conditions enhanced the rule-governed information processing during inductive reasoning. (Author/GDC)

  20. The Relationship Between Eye Movement and Vision Develops Before Birth

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    Veronika eSchöpf

    2014-10-01

    Full Text Available While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks.BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30 – 36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth.

  1. The relationship between eye movement and vision develops before birth.

    Science.gov (United States)

    Schöpf, Veronika; Schlegl, Thomas; Jakab, Andras; Kasprian, Gregor; Woitek, Ramona; Prayer, Daniela; Langs, Georg

    2014-01-01

    While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth.

  2. The relationship between eye movement and vision develops before birth

    Science.gov (United States)

    Schöpf, Veronika; Schlegl, Thomas; Jakab, Andras; Kasprian, Gregor; Woitek, Ramona; Prayer, Daniela; Langs, Georg

    2014-01-01

    While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30–36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth. PMID:25324764

  3. Abnormal Spontaneous Eye Movements as Initial Presentation of Organophosphate Poisoning

    Science.gov (United States)

    De Lima Teixeira, Igor; Bazan, Silméia Garcia Zanati; Schelp, Arthur Oscar; Luvizutto, Gustavo José; De Lima, Fabrício Diniz; Bazan, Rodrigo

    2017-01-01

    Background Atypical ocular bobbing may result from an intentional poisoning from an organophosphate compound. Phenomenology Shown The patient exhibited conjugated, slow, arrhythmic, unpredictable eye movements in all directions, diagnosed as atypical ocular bobbing. Educational Value This is a rare, well‐documented, clinically relevant case for medical students for correct diagnosis and appropriate treatment of organophosphate intoxication. PMID:28243486

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

    Science.gov (United States)

    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

    Science.gov (United States)

    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

    Science.gov (United States)

    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. Social experience does not abolish cultural diversity in eye movements

    Directory of Open Access Journals (Sweden)

    David J Kelly

    2011-05-01

    Full Text Available Adults from Eastern (e.g., China and Western (e.g., USA cultural groups display pronounced differences in a range of visual processing tasks. For example, the eye movement strategies used for information extraction during a variety of face processing tasks (e.g., identification and facial expressions of emotion categorization differs across cultural groups. Currently, many of the differences reported in previous studies have asserted that culture itself is responsible for shaping the way we process visual information, yet this has never been directly investigated. In the current study, we assessed the relative contribution of genetic and cultural factors by testing face processing in a population of British Born Chinese (BBC adults using face recognition and expression classification tasks. Contrary to predictions made by the cultural differences framework, the majority of BBC adults deployed ‘Eastern’ eye movement strategies, while approximately 25% of participants displayed ‘Western’ strategies. Furthermore, the cultural eye movement strategies used by individuals were consistent across recognition and expression tasks. These findings suggest that ‘culture’ alone cannot straightforwardly account for diversity in eye movement patterns. Instead a more complex understanding of how the environment and individual experiences can influence the mechanisms that govern visual processing is required.

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

    Science.gov (United States)

    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…

  9. Eye movement evidence for an immediate Ganong effect.

    Science.gov (United States)

    Kingston, John; Levy, Joshua; Rysling, Amanda; Staub, Adrian

    2016-12-01

    Listeners tend to categorize an ambiguous speech sound so that it forms a word with its context (Ganong, 1980). This effect could reflect feedback from the lexicon to phonemic activation (McClelland & Elman, 1986), or the operation of a task-specific phonemic decision system (Norris, McQueen, & Cutler, 2000). Because the former account involves feedback between lexical and phonemic levels, it predicts that the lexicon's influence on phonemic decisions should be delayed and should gradually increase in strength. Previous response time experiments have not delivered a clear verdict as to whether this is the case, however. In 2 experiments, listeners' eye movements were tracked as they categorized phonemes using visually displayed response options. Lexically relevant information in the signal, the timing of which was confirmed by separate gating experiments, immediately increased eye movements toward the lexically supported response. This effect on eye movements then diminished over the course of the trial rather than continuing to increase. These results challenge the lexical feedback account. The present work also introduces a novel method for analyzing data from 'visual-world' type tasks, designed to assess when an experimental manipulation influences the probability of an eye movement toward the target. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Eye-Movement Analysis Demonstrates Strategic Influences on Intelligence

    Science.gov (United States)

    Vigneau, Francois; Caissie, Andre F.; Bors, Douglas A.

    2006-01-01

    Taking into account various models and findings pertaining to the nature of analogical reasoning, this study explored quantitative and qualitative individual differences in intelligence using latency and eye-movement data. Fifty-five university students were administered 14 selected items of the Raven's Advanced Progressive Matrices test. Results…

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

    Science.gov (United States)

    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…

  12. Time trends and periodic cycles in REM sleep eye movements.

    Science.gov (United States)

    Krynicki, V

    1975-11-01

    Eye movements during REM sleep episodes were tabulated in 16 young adults. REM episodes were then broken down into four ranges according to length in min: (1) 11.0-21.3; (2) 21.7-29.7; (3) 30.0-42.3; (4) 42.7 or longer. These data were then analyzed for linear and quadratic trends. Eight episodes had a significant linear trend, 10 had a significant quadratic trend, 7 had both linear and quadratic trends, while 12 had no trend. The residuals from the best-fitting polynomial curve were then subject to a spectral analysis. In addition, 2 long periods of pre-sleep wakefulness (approximately 2 h each) were also analyzed. In general, the spectral analysis revealed the dominant presence of a slow cycle (period of 10 min to about 30 min) the exact period of which varied according to the length of the REM episode. A binomial probability test indicated that the presence of slow cycles was significant in REM episodes except for those in the 21-30 min range. For the episodes of wakefulness, a dominant slow cycle was found in both cases. The results give the impression of similarity in the periodic organization of eye movements during REM sleep and waking. The data also indicated that an ultradian (70-150 min) cycle was present in eye movements during sleep and waking. Further, the finding of a decrease in eye movements before sleep onset, coupled with previous reports of an increase in eye movement after sleep onset, indicate the presence of a circadian cycle.

  13. Interaction between the premotor processes of eye and hand movements: possible mechanism underlying eye-hand coordination.

    Science.gov (United States)

    Hiraoka, Koichi; Kurata, Naoatsu; Sakaguchi, Masato; Nonaka, Kengo; Matsumoto, Naoto

    2014-03-01

    Interaction between the execution process of eye movement and that of hand movement must be indispensable for eye-hand coordination. The present study investigated corticospinal excitability in the hand muscles during the premotor processes of eye and/or hand movement to elucidate interaction between these processes. Healthy humans performed a precued reaction task of eye and/or finger movement and motor-evoked potentials in the hand muscles were evoked in the reaction time. Leftward eye movement suppressed corticospinal excitability in the right abductor digiti minimi muscle only when little finger abduction was simultaneously executed. Corticospinal excitability in the first dorsal interosseous muscle was not suppressed by eye movement regardless of whether or not it was accompanied by finger movement. Suppression of corticospinal excitability in the hand muscles induced by eye movement in the premotor period depends on the direction of eye movement, the muscle tested, and the premotor process of the tested muscle. The suppression may reflect interaction between the motor process of eye movement and that of hand movement particularly active during eye-hand coordination tasks during which both processes proceed.

  14. Template aging in eye movement-driven biometrics

    Science.gov (United States)

    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.

  15. Seeing via miniature eye movements: A dynamic hypothesis for vision

    Directory of Open Access Journals (Sweden)

    Ehud eAhissar

    2012-11-01

    Full Text Available During natural viewing, the eyes are never still. Even during fixation, miniature movements of the eyes move the retinal image across tens of foveal photoreceptors. Most theories of vision implicitly assume that the visual system ignores these movements and somehow overcomes the resulting smearing. However, evidence has accumulated to indicate that fixational eye movements cannot be ignored by the visual system if fine spatial details are to be resolved. We argue that the only way the visual system can achieve its high resolution given its fixational movements is by seeing via these movements. Seeing via eye movements also eliminates the instability of the image, which would be induced by them otherwise. Here we present a hypothesis for vision, in which coarse details are spatially-encoded in gaze-related coordinates, and fine spatial details are temporally-encoded in relative retinal coordinates. The temporal encoding presented here achieves its highest resolution by encoding along the elongated axes of simple cell receptive fields and not across these axes as suggested by spatial models of vision. According to our hypothesis, fine details of shape are encoded by inter-receptor temporal phases, texture by instantaneous intra-burst rates of individual receptors, and motion by inter-burst temporal frequencies. We further describe the ability of the visual system to readout the encoded information and recode it internally. We show how reading out of retinal signals can be facilitated by neuronal phase-locked loops (NPLLs, which lock to the retinal jitter; this locking enables recoding of motion information and temporal framing of shape and texture processing. A possible implementation of this locking-and-recoding process by specific thalamocortical loops is suggested. Overall it is suggested that high-acuity vision is based primarily on temporal mechanisms of the sort presented here and low-acuity vision is based primarily on spatial mechanisms.

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

    Science.gov (United States)

    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.

  17. Comparing the accuracy of video-oculography and the scleral search coil system in human eye movement analysis.

    Science.gov (United States)

    Imai, Takao; Sekine, Kazunori; Hattori, Kousuke; Takeda, Noriaki; Koizuka, Izumi; Nakamae, Koji; Miura, Katsuyoshi; Fujioka, Hiromu; Kubo, Takeshi

    2005-03-01

    The measurement of eye movements in three dimensions is an important tool to investigate the human vestibular and oculomotor system. The primary methods for three dimensional eye movement measurement are the scleral search coil system (SSCS) and video-oculography (VOG). In the present study, we compare the accuracy of VOG with that of SSCS using an artificial eye. We then analyzed the Y (pitch) and Z (yaw) component of human eye movements during saccades, smooth pursuit and optokinetic nystagmus, and the X (roll) component of human eye movement during the torsional vestibulo-ocular reflex induced by rotation in normal subjects, using simultaneous VOG and SSCS measures. The coefficients of the linear relationship between the angle of a simulated eyeball and the angle measured by both VOG and SSCS was almost unity with y-intercepts close to zero for torsional (X), vertical (Y) and horizontal (Z) movements, indicating that the in vitro accuracy of VOG was similar to that of SSCS. The average difference between VOG and SSCS was 0.56 degrees , 0.78 degrees and 0.18 degrees for the X, Y and Z components of human eye movements, respectively. Both the in vitro and in vivo comparisons demonstrate that VOG has accuracy comparable to SSCS, and is a reliable method for measurement of three dimensions (3D) human eye movements.

  18. The eyes have it: hippocampal activity predicts expression of memory in eye movements.

    Science.gov (United States)

    Hannula, Deborah E; Ranganath, Charan

    2009-09-10

    Although there is widespread agreement that the hippocampus is critical for explicit episodic memory retrieval, it is controversial whether this region can also support indirect expressions of relational memory when explicit retrieval fails. Here, using functional magnetic resonance imaging (fMRI) with concurrent indirect, eye-movement-based memory measures, we obtained evidence that hippocampal activity predicted expressions of relational memory in subsequent patterns of viewing, even when explicit, conscious retrieval failed. Additionally, activity in the lateral prefrontal cortex and functional connectivity between the hippocampus and prefrontal cortex were greater for correct than for incorrect trials. Together, these results suggest that hippocampal activity can support the expression of relational memory even when explicit retrieval fails and that recruitment of a broader cortical network may be required to support explicit associative recognition.

  19. Eye Movements Affect Postural Control in Young and Older Females.

    Science.gov (United States)

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

    2016-01-01

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

  20. Driving experience and special skills reflected in eye movements

    Science.gov (United States)

    Paeglis, Roberts; Bluss, Kristaps; Atvars, Aigars

    2011-10-01

    When driving a vehicle, people use the central vision both to plan ahead and monitor their performance feedback (research by Donges, 1978 [1], and after). Discussion is ongoing if making eye movements do more than gathering information. Moving eyes may also prepare the following body movements like steering. Different paradigms exist to explore vision in driving. Our perspective was to quantify eye movements and fixation patterns of different proficiency individuals, a driving learner, a novice, an experienced driver and a European level car racer. Thus for safety reasons we started by asking them to follow a video tour through a known city, remote from an infrared eye tracker sampling at 250 Hz. We report that gaze strategy of an experienced driver differs qualitatively from that of an automobile sports master. Quantitative differences only were found between the latter and a driving learner or a novice driver. Experience in a motor action provides skills different from sports training. We are aiming at testing this finding in real world driving.

  1. Eye movement desensitization in fibromyalgia: a pilot study.

    Science.gov (United States)

    Friedberg, Fred

    2004-11-01

    The purpose of this study was to investigate the effectiveness of eye movement desensitization (EMD) for the relief of pain, fatigue and anxiety and depression in fibromyalgia patients. Six Caucasian female patients (mean age=43.2 yr) participated in two treatment sessions. Outcome assessments included the Fibromyalgia Impact Questionnaire, Fatigue Scale, Beck Anxiety Inventory, and Beck Depression Inventory. In-session process measures included thermal biofeedback monitoring and subjective units of discomfort ratings of pain, stress, and fatigue. Four out of six subjects were considered treatment responders. Thermal biofeedback monitoring revealed an average increase in hand temperature of 5.4 degrees indicating a relaxation effect. At treatment termination, average scores decreased on the measures of anxiety (28.6%), depression (29.9%), fibromyalgia impact (12.6%), and fatigue (11.5%). At the 3-month follow-up assessment, total reductions in average scores from pre-treatment baseline reflected further improvements on measures of anxiety (45.8%), depression (31.6%), fibromyalgia impact (19.2%), and fatigue (26.7%). Because EMD produced a somewhat automatic relaxation response with minimal patient participation, it may be especially useful when standard relaxation techniques fail.

  2. Roles of eyes, leg proprioceptors and statocysts in the compensatory eye movements of freely walking land crabs (Cardisoma guanhumi)

    Science.gov (United States)

    Paul; Barnes; Varju

    1998-12-01

    The compound eyes, the canal organs of the statocysts and proprioceptors in the legs all generate compensatory eye movements in the horizontal plane in the land crab Cardisoma guanhumi. Frequency analyses of the compensatory eye reflexes elicited by each of these inputs show that visual (V) and proprioceptive (P) reflexes respond best below 0.1 Hz, while statocyst (S) reflexes only achieve a high gain above this frequency. They thus increase the range of frequencies over which compensation can occur. Eye and body movements were recorded in an arena under all possible combinations of crabs seeing or blind (V+ or V-), with or without statocysts (S+ or S-) and freely walking or passively transported on a trolley (P+ or P-). Intact crabs (V+S+P+) show good stabilisation of the eyes in space, the only movements with respect to external coordinates being saccadic resetting movements (fast phases of nystagmus). The eyes thus compensate well for body turns, but are unaffected by translatory movements of the body and turns that are not accompanied by a change in the orientation of the long axis of the body in space. In the absence of any one sense, compensation for rotation is significantly impaired, whether measured by the increase in the width of the histograms of changes in the angular positions of the eyes in space ( capdelta &phgr; E), by the mean angular velocity of the eyes (slope of regression line, mE) with respect to the angular velocity of the body (mB) or by response gain plotted against angular acceleration of body turn (a). The absence of two senses reduces the crab's ability to compensate still further, with the statocyst-only condition (V-S+P-) being little better than the condition when all three senses are absent (V-S-P-).Such multisensory control of eye compensation for body rotation is discussed both in terms of making use of every available cue for reducing retinal slip and in making available the information content of the optic flow field.

  3. Fixational eye movements during viewing of dynamic natural scenes.

    Science.gov (United States)

    Roberts, James A; Wallis, Guy; Breakspear, Michael

    2013-01-01

    Even during periods of fixation our eyes undergo small amplitude movements. These movements are thought to be essential to the visual system because neural responses rapidly fade when images are stabilized on the retina. The considerable recent interest in fixational eye movements (FEMs) has thus far concentrated on idealized experimental conditions with artificial stimuli and restrained head movements, which are not necessarily a suitable model for natural vision. Natural dynamic stimuli, such as movies, offer the potential to move beyond restrictive experimental settings to probe the visual system with greater ecological validity. Here, we study FEMs recorded in humans during the unconstrained viewing of a dynamic and realistic visual environment, revealing that drift trajectories exhibit the properties of a random walk with memory. Drifts are correlated at short time scales such that the gaze position diverges from the initial fixation more quickly than would be expected for an uncorrelated random walk. We propose a simple model based on the premise that the eye tends to avoid retracing its recent steps to prevent photoreceptor adaptation. The model reproduces key features of the observed dynamics and enables estimation of parameters from data. Our findings show that FEM correlations thought to prevent perceptual fading exist even in highly dynamic real-world conditions.

  4. Fixational eye movements during viewing of dynamic natural scenes

    Directory of Open Access Journals (Sweden)

    James A. Roberts

    2013-10-01

    Full Text Available Even during periods of fixation our eyes undergo small amplitude movements. These movements are thought to be essential to the visual system because neural responses rapidly fade when images are stabilized on the retina. The considerable recent interest in fixational eye movements (FEMs has thus far concentrated on idealized experimental conditions with artificial stimuli and restrained head movements, which are not necessarily a suitable model for natural vision. Natural dynamic stimuli, such as movies, offer the potential to move beyond restrictive experimental settings to probe the visual system with greater ecological validity. Here, we study FEMs recorded in humans during the unconstrained viewing of a dynamic and realistic visual environment, revealing that drift trajectories exhibit the properties of a random walk with memory. Drifts are correlated at short time scales such that the gaze position diverges from the initial fixation more quickly than would be expected for an uncorrelated random walk. We propose a simple model based on the premise that the eye tends to avoid retracing its recent steps to prevent photoreceptor adaptation. The model reproduces key features of the observed dynamics and enables estimation of parameters from data. Our findings show that FEM correlations thought to prevent perceptual fading exist even in highly dynamic real-world conditions.

  5. Detection of cortical activities on eye movement using functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masaki; Kawai, Kazushige; Kitahara, Kenji [Jikei Univ., Tokyo (Japan). School of Medicine; Soulie, D.; Cordoliani, Y.S.; Iba-Zizen, M.T.; Cabanis, E.A.

    1997-11-01

    Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann`s areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann`s areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement. (author)

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

    Science.gov (United States)

    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.

  7. Novel method for evaluation of eye movements in patients with narcolepsy

    DEFF Research Database (Denmark)

    Christensen, Julie A E; Kempfner, Lykke; Leonthin, Helle L

    2017-01-01

    BACKGROUND: Narcolepsy causes abnormalities in the control of wake-sleep, non-rapid-eye-movement (non-REM) sleep and REM sleep, which inlcudes specific eye movements (EMs). In this study, we aim to evaluate EM characteristics in narcolepsy as compared to controls using an automated detector...... for central hypersomnias. Based on PSG, multiple sleep latency test and cerebrospinal fluid hypocretin-1 measures, they were divided into clinical controls (N = 20), narcolepsy type 2 (NT2, N = 19), and narcolepsy type 1 (NT1, N = 28). We investigated the distribution of EMs across sleep stages and cycles...

  8. Origin, development, and evolution of eye movement desensitization and reprocessing

    Directory of Open Access Journals (Sweden)

    Carolina Marín

    2016-12-01

    Full Text Available Eye movement desensitization and reprocessing (EMDR has led to a great number of studies since its appearance in 1989. The aim of this article is to describe EMDR development and evolution to the present day. With this purpose a search was carried out on MEDLINE and PsycINFO with the entry "eye movement desensitization". After revising the resulting 797 articles, those that because of their relevance explained best the development and evolution of the technique were chosen and shaped into a lifeline graphically representing the history of EMDR. Despite the fact that during the first years the focus of research was on the validation of the technique for post-traumatic disorder (PTSD, it was soon applied to other areas. Only 14% of the articles found account for controlled studies. Up to date, in spite of the effectiveness of EMDR for the treatment of PTSD that has been proven, many different explanatory hypotheses are still up for discussion.

  9. Characteristics of rapid eye movement sleep behavior disorder in narcolepsy

    DEFF Research Database (Denmark)

    Jennum, Poul Jørgen; Frandsen, Rune Asger Vestergaard; Knudsen, Stine

    2013-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream-enacting behavior and impaired motor inhibition during REM sleep (REM sleep without atonia, RSWA). RBD is commonly associated with Parkinsonian disorders, but is also reported in narcolepsy. Most patients with narcol......Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream-enacting behavior and impaired motor inhibition during REM sleep (REM sleep without atonia, RSWA). RBD is commonly associated with Parkinsonian disorders, but is also reported in narcolepsy. Most patients...... 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....

  10. Eye movements of patients with schizophrenia in a natural environment.

    Science.gov (United States)

    Dowiasch, Stefan; Backasch, Bianca; Einhäuser, Wolfgang; Leube, Dirk; Kircher, Tilo; Bremmer, Frank

    2016-02-01

    Alterations of eye movements in schizophrenia patients have been widely described for laboratory settings. For example, gain during smooth tracking is reduced, and fixation patterns differ between patients and healthy controls. The question remains, whether such results are related to the specifics of the experimental environment, or whether they transfer to natural settings. Twenty ICD-10 diagnosed schizophrenia patients and 20 healthy age-matched controls participated in the study, each performing four different oculomotor tasks corresponding to natural everyday behavior in an indoor environment: (I) fixating stationary targets, (II) sitting in a hallway with free gaze, (III) walking down the hallway, and (IV) visually tracking a target on the floor while walking straight-ahead. In all conditions, eye movements were continuously recorded binocularly by a mobile lightweight eye tracker (EyeSeeCam). When patients looked at predefined targets, they showed more fixations with reduced durations than controls. The opposite was true when participants were sitting in a hallway with free gaze. During visual tracking, patients showed a significantly greater root-mean-square error (representing the mean deviation from optimal) of retinal target velocity. Different from previous results on smooth-pursuit eye movements obtained in laboratory settings, no such difference was found for velocity gain. Taken together, we have identified significant differences in fundamental oculomotor parameters between schizophrenia patients and healthy controls during natural behavior in a real environment. Moreover, our data provide evidence that in natural settings, patients overcome some impairments, which might be present only in laboratory studies, by as of now unknown compensatory mechanisms or strategies.

  11. Neurophysiological basis of rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    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...... 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....

  12. A complex choreography of cell movements shapes the vertebrate eye.

    Science.gov (United States)

    Kwan, Kristen M; Otsuna, Hideo; Kidokoro, Hinako; Carney, Keith R; Saijoh, Yukio; Chien, Chi-Bin

    2012-01-01

    Optic cup morphogenesis (OCM) generates the basic structure of the vertebrate eye. Although it is commonly depicted as a series of epithelial sheet folding events, this does not represent an empirically supported model. Here, we combine four-dimensional imaging with custom cell tracking software and photoactivatable fluorophore labeling to determine the cellular dynamics underlying OCM in zebrafish. Although cell division contributes to growth, we find it dispensable for eye formation. OCM depends instead on a complex set of cell movements coordinated between the prospective neural retina, retinal pigmented epithelium (RPE) and lens. Optic vesicle evagination persists for longer than expected; cells move in a pinwheel pattern during optic vesicle elongation and retinal precursors involute around the rim of the invaginating optic cup. We identify unanticipated movements, particularly of central and peripheral retina, RPE and lens. From cell tracking data, we generate retina, RPE and lens subdomain fate maps, which reveal novel adjacencies that might determine corresponding developmental signaling events. Finally, we find that similar movements also occur during chick eye morphogenesis, suggesting that the underlying choreography is conserved among vertebrates.

  13. Eye movements during object recognition in visual agnosia.

    Science.gov (United States)

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

    2012-07-01

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

  14. Eye Movement Desensitization and Reprocessing (EMDR) Treatment for Psychologically Traumatized Individuals.

    Science.gov (United States)

    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…

  15. Eye movements to yaw, pitch, and roll about vertical and horizontal axes : Adaptation, and motion sickness

    NARCIS (Netherlands)

    Bos, J.E.; Bles, W.; Graaf, B. de

    2002-01-01

    Background: In the search for parameters to predict motion sickness that can be measured in the laboratory, we performed a longitudinal investigation in aviators. Since the vestibular system is involved in the generation of motion sickness as well as eye movements, vestibulo-ocular reflex (VOR) para

  16. Does Visual Attention Span Relate to Eye Movements during Reading and Copying?

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Sakari Kallio

    Full Text Available 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.

  19. The Effect of Cataract on Eye Movement Perimetry

    Directory of Open Access Journals (Sweden)

    G. Thepass

    2015-01-01

    Full Text Available Purpose. To determine how different grades of cataract affect sensitivity threshold and saccadic reaction time (SRT in eye movement perimetry (EMP. Methods. In EMP, the visual field is tested by assessing the saccades that a subject makes towards peripheral stimuli using an eye tracker. Forty-eight cataract patients underwent pre- and postoperative EMP examination in both eyes. The subjects had to fix a central stimulus presented on the eye tracker monitor and to look at any detected peripheral stimulus upon its appearance. A multilevel mixed model was used to determine the factors that affected the sensitivity threshold and the SRT as a function of cataract grade. Results. We found no effect of cataract severity (LOCS III grades I through IV on SRT and the sensitivity thresholds. In cataract of LOCS III grade V, however, we found an increase by 27% and 21% (p<0.001, respectively, compared to the SRT and the sensitivity threshold in LOCS III grade I. Eyes that underwent cataract surgery showed no change in mean SRTs and sensitivity thresholds after surgery in LOCS III grade IV and lower. Conclusion. The present study shows that EMP can be readily used in patients with cataract with LOCS III grade IV and below.

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

    Science.gov (United States)

    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.

  1. Chromatic contrast sensitivity during optokinetic nystagmus, visually enhanced vestibulo-ocular reflex, and smooth pursuit eye movements.

    Science.gov (United States)

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

    2009-05-01

    Recently we showed that sensitivity for chromatic- and high-spatial frequency luminance stimuli is enhanced during smooth-pursuit eye movements (SPEMs). Here we investigated whether this enhancement is a general property of slow eye movements. Besides SPEM there are two other classes of eye movements that operate in a similar range of eye velocities: the optokinetic nystagmus (OKN) is a reflexive pattern of alternating fast and slow eye movements elicited by wide-field visual motion and the vestibulo-ocular reflex (VOR) stabilizes the gaze during head movements. In a natural environment all three classes of eye movements act synergistically to allow clear central vision during self- and object motion. To test whether the same improvement of chromatic sensitivity occurs during all of these eye movements, we measured human detection performance of chromatic and luminance line stimuli during OKN and contrast sensitivity during VOR and SPEM at comparable velocities. For comparison, performance in the same tasks was tested during fixation. During the slow phase of OKN we found a similar enhancement of chromatic detection rate like that during SPEM, whereas no enhancement was observable during VOR. This result indicates similarities between slow-phase OKN and SPEM, which are distinct from VOR.

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

    Science.gov (United States)

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

    2016-07-08

    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.

  3. Rapid eye movement sleep behaviour disorder in patients with narcolepsy is associated with hypocretin-1 deficiency

    DEFF Research Database (Denmark)

    Knudsen, Stine; Gammeltoft, Steen; Jennum, Poul J

    2010-01-01

    Rapid eye movement sleep behaviour disorder is characterized by dream-enacting behaviour and impaired motor inhibition during rapid eye movement sleep. Rapid eye movement sleep behaviour disorder is commonly associated with neurodegenerative disorders, but also reported in narcolepsy with cataplexy....... Most narcolepsy with cataplexy patients lack the sleep-wake, and rapid eye movement sleep, motor-regulating hypocretin neurons in the lateral hypothalamus. In contrast, rapid eye movement sleep behaviour disorder and hypocretin deficiency are rare in narcolepsy without cataplexy. We hypothesized...... that rapid eye movement sleep behaviour disorder coexists with cataplexy in narcolepsy due to hypocretin deficiency. In our study, rapid eye movement sleep behaviour disorder was diagnosed by the International Classification of Sleep Disorders (2nd edition) criteria in 63 narcolepsy patients with or without...

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

    Directory of Open Access Journals (Sweden)

    Lauren S Hopkins

    Full Text Available 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.

  5. Efficient feature for classification of eye movements using electrooculography signals

    Directory of Open Access Journals (Sweden)

    Phukpattaranont Pornchai

    2016-01-01

    Full Text Available Electrooculography (EOG signal is widely and successfully used to detect activities of human eye. The advantages of the EOG-based interface over other conventional interfaces have been presented in the last two decades; however, due to a lot of information in EOG signals, the extraction of useful features should be done before the classification task. In this study, an efficient feature extracted from two directional EOG signals: vertical and horizontal signals has been presented and evaluated. There are the maximum peak and valley amplitude values, the maximum peak and valley position values, and slope, which are derived from both vertical and horizontal signals. In the experiments, EOG signals obtained from five healthy subjects with ten directional eye movements were employed: up, down, right, left, up-right, up-left, down-right down-left clockwise and counterclockwise. The mean feature values and their standard deviations have been reported. The difference between the mean values of the proposed feature from different eye movements can be clearly seen. Using the scatter plot, the differences in features can be also clearly observed. Results show that classification accuracy can approach 100% with a simple distinction feature rule. The proposed features can be useful for various advanced human-computer interface applications in future researches.

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

    Science.gov (United States)

    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.

  7. Smooth pursuit eye movements improve temporal resolution for color perception.

    Directory of Open Access Journals (Sweden)

    Masahiko Terao

    Full Text Available Human observers see a single mixed color (yellow when different colors (red and green rapidly alternate. Accumulating evidence suggests that the critical temporal frequency beyond which chromatic fusion occurs does not simply reflect the temporal limit of peripheral encoding. However, it remains poorly understood how the central processing controls the fusion frequency. Here we show that the fusion frequency can be elevated by extra-retinal signals during smooth pursuit. This eye movement can keep the image of a moving target in the fovea, but it also introduces a backward retinal sweep of the stationary background pattern. We found that the fusion frequency was higher when retinal color changes were generated by pursuit-induced background motions than when the same retinal color changes were generated by object motions during eye fixation. This temporal improvement cannot be ascribed to a general increase in contrast gain of specific neural mechanisms during pursuit, since the improvement was not observed with a pattern flickering without changing position on the retina or with a pattern moving in the direction opposite to the background motion during pursuit. Our findings indicate that chromatic fusion is controlled by a cortical mechanism that suppresses motion blur. A plausible mechanism is that eye-movement signals change spatiotemporal trajectories along which color signals are integrated so as to reduce chromatic integration at the same locations (i.e., along stationary trajectories on the retina that normally causes retinal blur during fixation.

  8. Fourth Graders' Cognitive Processes and Learning Strategies for Reading Illustrated Biology Texts: Eye Movement Measurements

    Science.gov (United States)

    Jian, Yu-Cin

    2016-01-01

    Previous research suggests that multiple representations can improve science reading comprehension. This facilitation effect is premised on the observation that readers can efficiently integrate information in text and diagram formats; however, this effect in young readers is still contested. Using eye-tracking technology and sequential analysis,…

  9. Fourth Graders' Cognitive Processes and Learning Strategies for Reading Illustrated Biology Texts: Eye Movement Measurements

    Science.gov (United States)

    Jian, Yu-Cin

    2016-01-01

    Previous research suggests that multiple representations can improve science reading comprehension. This facilitation effect is premised on the observation that readers can efficiently integrate information in text and diagram formats; however, this effect in young readers is still contested. Using eye-tracking technology and sequential analysis,…

  10. Effect of eye movements and proprioceptive neuromuscular facilitation on balance and head alignment in stroke patients with neglect syndrome.

    Science.gov (United States)

    Park, Si-Eun; Min, Kyung-Ok; Lee, Sang-Bin; Choi, Wan-Suk; Kim, Soon-Hee

    2016-01-01

    [Purpose] The purpose of this study was to assess the effect of eye movements and proprioceptive neuromuscular facilitation (PNF) on patients with neglect syndrome. [Subjects and Methods] The subjects were randomly allocated to 2 groups: the eye movements (EM) group; and the PNF with eye movements (PEM) group. The program was conducted five times each week for 6 weeks. Balance (both static and dynamic) and head alignment (craniovertebral angle and cranial rotation angle) were measured before and after testing. [Results] In measurements of static balance, the EM group showed significant improvement in sway length and sway area when examined in the eyes-open condition, but not when examined in the eyes-closed condition. The PEM group showed significant improvement when examined under both conditions. In the assessment of dynamic balance, both groups showed significant improvement in measurements of sway areas. With respect to head alignment, there were no significant differences pre- and post-testing in either the craniovertebral angle or the cranial rotation angle in the EM group, but the PEM group showed significant differences in both measurements. [Conclusion] These results suggest that in stroke patients with neglect syndrome, PNF with eye movements, rather than eye movements alone, has a greater positive effect on balance and head alignment.

  11. Inspection time as mental speed in mildly mentally retarded adults: analysis of eye gaze, eye movement, and orientation.

    Science.gov (United States)

    Nettelbeck, T; Robson, L; Walwyn, T; Downing, A; Jones, N

    1986-07-01

    The effect of eye movements away from a target on accuracy of visual discrimination was examined. In Experiment I inspection time was measured for 10 mildly mentally retarded and 10 nonretarded adults under two conditions, with each trial initiated by the subject or under experimental control. Retarded subjects did not gain any advantage from controlling trial onset. Video records of eye movements revealed that retarded subjects glanced off-target more than did nonretarded controls, but this was not sufficient to explain appreciably slower inspection time of the retarded group. Experiment 2 supported this conclusion; the same subjects completed a letter-discrimination task with direction of gaze monitored automatically. Although retarded subjects' eye gaze was more scattered early during a trial, gaze was appropriately directed by the time that the target appeared. Results from both experiments supported the hypothesis that speed of central, perceptual processing is slower among retarded persons, over and above the influence of distractibility. Results from three experiments in Part II were consistent with this interpretation. Experiment 3 was designed to eradicate trials among retarded subjects in which gaze was not properly directed, but results showed that too few such events occurred to influence accuracy. Experiment 4 demonstrated that the preparatory procedure in the previous studies resulted in efficient eye gaze among retarded subjects. Experiment 5 confirmed that lower discriminative accuracy among 10 retarded adults (compared with 10 nonretarded controls) was not due to less-efficient orientation prior to discrimination.

  12. The acquisition of reading fluency in an orthographically transparent language (Italian): an eye movement longitudinal study.

    Science.gov (United States)

    De Luca, Maria; Zeri, Fabrizio; Spinelli, Donatella; Zoccolotti, Pierluigi

    2010-03-01

    The aim of this study was to examine longitudinally the acquisition of reading fluency in a shallow orthography from the very beginning using eye movement recordings. The development of reading fluency is easier to examine in shallow (such as German, Finnish, or Italian) rather than in opaque (such as English or French) orthographies because the former limit the presence of speed-accuracy trade-offs at early stages of acquisition. To date, only cross-sectional eye movement studies of reading development are available. One normally developing child was assessed at the very beginning of first grade and at the end of the first, second, and fifth grades. Eye movement parameters during reading, reading speed and accuracy in a standard reading test, and vocal reaction time at onset to single words varying in length were measured. Reading fluency improved dramatically during the first grade and progressively less thereafter: the word-length effect decreased abruptly by the end of the first grade and then less onwards. The rate of improvement closely followed a power function. This pattern held for standard reading tests, various eye movement parameters during reading, and vocal reaction times to single word onset. These longitudinal observations indicate the rapid acquisition of reading fluency in a transparent orthography showing that the largest changes occurred within the first year of education.

  13. Like a rolling stone: naturalistic visual kinematics facilitate tracking eye movements.

    Science.gov (United States)

    Souto, David; Kerzel, Dirk

    2013-02-06

    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.

  14. Eye movement desensitization and reprocessing: a conceptual framework.

    Science.gov (United States)

    Menon, Sukanya B; Jayan, C

    2010-07-01

    Eye movement desensitization and reprocessing (EMDR) is a method which was initially used for the treatment of post-traumatic stress disorder. But it is now being used in different therapeutic situations. EMDR is an eight-phase treatment method. History taking, client preparation, assessment, desensitization, installation, body scan, closure and reevaluation of treatment effect are the eight phases of this treatment which are briefly described. A case report is also depicted which indicates the efficacy of EMDR. The areas where EMDR is used and the possible ways through which it is working are also described.

  15. Sexual violence: psychiatric healing with eye movement reprocessing and desensitization.

    Science.gov (United States)

    Posmontier, Bobbie; Dovydaitis, Tiffany; Lipman, Kenneth

    2010-08-01

    Sexual violence, which affects one in three women worldwide, can result in significant psychiatric morbidity and suicide. Eye movement desensitization and reprocessing (EMDR) offers health care providers the option of a brief psychiatric intervention that can result in psychiatric healing in as few as four sessions. Because health care providers often hear stories of sexual violence from their patients, they are in an ideal position to make recommendations for treatment. The purpose of this article is to introduce health care providers to the technique of EMDR, review safety and appropriateness, and discuss clinical and research implications.

  16. Neuregulin-1 genotypes and eye movements in schizophrenia

    DEFF Research Database (Denmark)

    Haraldsson, H.M.; Ettinger, U.; Magnusdottir, B.B.;

    2010-01-01

    Neuregulin-1 (NRG-1) is a putative susceptibility gene for schizophrenia but the neurocognitive processes that may involve NRG-1 in schizophrenia are unknown. Deficits in antisaccade (AS) and smooth pursuit eye movements (SPEM) are promising endophenotypes, which may be associated with brain...... dysfunctions underlying the pathophysiology of schizophrenia. The aim of this study was to investigate the associations of NRG-1 genotypes with AS and SPEM in schizophrenia patients and healthy controls. Patients (N = 113) and controls (N = 106) were genotyped for two NRG-1 single nucleotide polymorphisms...... findings of impaired AS and SPEM performance in schizophrenia patients (all P

  17. Eye movement desensitization and reprocessing: A conceptual framework

    Directory of Open Access Journals (Sweden)

    Menon Sukanya

    2010-01-01

    Full Text Available Eye movement desensitization and reprocessing (EMDR is a method which was initially used for the treatment of post-traumatic stress disorder. But it is now being used in different therapeutic situations. EMDR is an eight-phase treatment method. History taking, client preparation, assessment, desensitization, installation, body scan, closure and reevaluation of treatment effect are the eight phases of this treatment which are briefly described. A case report is also depicted which indicates the efficacy of EMDR. The areas where EMDR is used and the possible ways through which it is working are also described.

  18. Neurophysiological basis of rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Jennum, Poul; Christensen, Julie Anja Engelhard; 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...

  19. The contributions of eye movements to the efficacy of brief exposure treatment for reducing fear of public speaking.

    Science.gov (United States)

    Carrigan, M H; Levis, D J

    1999-01-01

    The present study was designed to isolate the effects of the eye-movement component of the Eye Movement Desensitization and Reprocessing (EMDR) procedure in the treatment of fear of public speaking. Seventy-one undergraduate psychology students who responded in a fearful manner on the Fear Survey Schedule II and on a standardized, self-report measure of public speaking anxiety (Personal Report of Confidence as a Speaker; PRCS) were randomly assigned to one of four groups in a 2x2 factorial design. The two independent variables assessed were treatment condition (imagery plus eye movements vs. imagery alone) and type of imagery (fear-relevant vs. relaxing). Dependent variables assessed were self-reported and physiological anxiety during exposure and behavioral indices of anxiety while giving a speech. Although process measures indicated exposure to fear-relevant imagery increased anxiety during the procedure, no significant differences among groups were found on any of the outcome measures, except that participants who received eye movements were less likely to give a speech posttreatment than participants who did not receive eye movements. Addition of the eye movements to the experimental procedure did not result in enhancement of fear reduction. It was concluded, consistent with the results of past research, that previously reported positive effects of the EMDR procedure may be largely due to exposure to conditioned stimuli.

  20. Fooling the eyes: the influence of a sound-induced visual motion illusion on eye movements.

    Directory of Open Access Journals (Sweden)

    Alessio Fracasso

    Full Text Available The question of whether perceptual illusions influence eye movements is critical for the long-standing debate regarding the separation between action and perception. To test the role of auditory context on a visual illusion and on eye movements, we took advantage of the fact that the presence of an auditory cue can successfully modulate illusory motion perception of an otherwise static flickering object (sound-induced visual motion effect. We found that illusory motion perception modulated by an auditory context consistently affected saccadic eye movements. Specifically, the landing positions of saccades performed towards flickering static bars in the periphery were biased in the direction of illusory motion. Moreover, the magnitude of this bias was strongly correlated with the effect size of the perceptual illusion. These results show that both an audio-visual and a purely visual illusion can significantly affect visuo-motor behavior. Our findings are consistent with arguments for a tight link between perception and action in localization tasks.

  1. Effect of Putting Grip on Eye and Head Movements During the Golf Putting Stroke

    Directory of Open Access Journals (Sweden)

    George K. Hung

    2003-01-01

    Full Text Available The objective of this article is to determine the effect of three different putting grips (conventional, cross-hand, and one-handed on variations in eye and head movements during the putting stroke. Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3-s interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about an imaginary axis through the top of the head and its center-of-rotation was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (STD, relative to the initial level was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact. The averaged STD for the attempted putts was calculated for each subject. Then, the averaged STDs and other data for the seven subjects were statistically compared across the three grip conditions. The STD of eye movements were greater (p < 0.1 for conventional than cross-hand (9 ft and one-handed (3 and 9 ft grips. Also, the STD of head movements were greater (p < 0.1; 3 ft for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was

  2. CEFR and Eye Movement Characteristics during EFL Reading: The Case of Intermediate Readers

    Science.gov (United States)

    Dolgunsöz, Emrah; Sariçoban, Arif

    2016-01-01

    This study primarily aims to (1) examine the relationship between foreign language reading proficiency and eye movements during reading, and (2) to describe eye movement differences between two CEFR proficiency groups (B1 and B2) by using eye tracking technique. 57 learners of EFL were tested under two experimental conditions: Natural L2 reading…

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

    Science.gov (United States)

    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.

  4. EMDR: eye movements superior to beeps in taxing working memory and reducing vividness of recollections.

    Science.gov (United States)

    van den Hout, Marcel A; Engelhard, Iris M; Rijkeboer, Marleen M; Koekebakker, Jutte; Hornsveld, Hellen; Leer, Arne; Toffolo, Marieke B J; Akse, Nienke

    2011-02-01

    Posttraumatic stress disorder (PTSD) is effectively treated with eye movement desensitization and reprocessing (EMDR) with patients making eye movements during recall of traumatic memories. Many therapists have replaced eye movements with bilateral beeps, but there are no data on the effects of beeps. Experimental studies suggest that eye movements may be beneficial because they tax working memory, especially the central executive component, but the presence/degree of taxation has not been assessed directly. Using discrimination Reaction Time (RT) tasks, we found that eye movements slow down RTs to auditive cues (experiment I), but binaural beeps do not slow down RTs to visual cues (experiment II). In an arguably more sensitive "Random Interval Repetition" task using tactile stimulation, working memory taxation of beeps and eye movements were directly compared. RTs slowed down during beeps, but the effects were much stronger for eye movements (experiment III). The same pattern was observed in a memory experiment with healthy volunteers (experiment IV): vividness of negative memories was reduced after both beeps and eye movements, but effects were larger for eye movements. Findings support a working memory account of EMDR and suggest that effects of beeps on negative memories are inferior to those of eye movements.

  5. Are smooth pursuit eye movements altered in chronic whiplash-associated disorders? A cross-sectional study

    DEFF Research Database (Denmark)

    Kongsted, Alice; Jørgensen, L V; Bendix, T

    2007-01-01

    To evaluate whether smooth pursuit eye movements differed between patients with long-lasting whiplash-associated disorders and controls when using a purely computerized method for the eye movement analysis.......To evaluate whether smooth pursuit eye movements differed between patients with long-lasting whiplash-associated disorders and controls when using a purely computerized method for the eye movement analysis....

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Alexis D J Makin

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  10. Rapid eye movements during sleep in mice: High trait-like stability qualifies rapid eye movement density for characterization of phenotypic variation in sleep patterns of rodents

    Directory of Open Access Journals (Sweden)

    Fulda Stephany

    2011-11-01

    Full Text Available Abstract Background In humans, rapid eye movements (REM density during REM sleep plays a prominent role in psychiatric diseases. Especially in depression, an increased REM density is a vulnerability marker for depression. In clinical practice and research measurement of REM density is highly standardized. In basic animal research, almost no tools are available to obtain and systematically evaluate eye movement data, although, this would create increased comparability between human and animal sleep studies. Methods We obtained standardized electroencephalographic (EEG, electromyographic (EMG and electrooculographic (EOG signals from freely behaving mice. EOG electrodes were bilaterally and chronically implanted with placement of the electrodes directly between the musculus rectus superior and musculus rectus lateralis. After recovery, EEG, EMG and EOG signals were obtained for four days. Subsequent to the implantation process, we developed and validated an Eye Movement scoring in Mice Algorithm (EMMA to detect REM as singularities of the EOG signal, based on wavelet methodology. Results The distribution of wakefulness, non-REM (NREM sleep and rapid eye movement (REM sleep was typical of nocturnal rodents with small amounts of wakefulness and large amounts of NREM sleep during the light period and reversed proportions during the dark period. REM sleep was distributed correspondingly. REM density was significantly higher during REM sleep than NREM sleep. REM bursts were detected more often at the end of the dark period than the beginning of the light period. During REM sleep REM density showed an ultradian course, and during NREM sleep REM density peaked at the beginning of the dark period. Concerning individual eye movements, REM duration was longer and amplitude was lower during REM sleep than NREM sleep. The majority of single REM and REM bursts were associated with micro-arousals during NREM sleep, but not during REM sleep. Conclusions Sleep

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

    Science.gov (United States)

    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

  12. Edge Detection Model Based on Involuntary Eye Movements of the Eye-Retina System

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    András Róka

    2007-03-01

    Full Text Available Traditional edge-detection algorithms in image processing typically convolute afilter operator and the input image, and then map overlapping input image regions tooutput signals. Convolution also serves as a basis in biologically inspired (Sobel, Laplace,Canny algorithms. Recent results in cognitive retinal research have shown that ganglioncell receptive fields cover the mammalian retina in a mosaic arrangement, withinsignificant amounts of overlap in the central fovea. This means that the biologicalrelevance of traditional and widely adapted edge-detection algorithms with convolutionbasedoverlapping operator architectures has been disproved. However, using traditionalfilters with non-overlapping operator architectures leads to considerable losses in contourinformation. This paper introduces a novel, tremor-based retina model and edge-detectionalgorithm that reconciles these differences between the physiology of the retina and theoverlapping architectures used by today's widely adapted algorithms. The algorithm takesinto consideration data convergence, as well as the dynamic properties of the retina, byincorporating a model of involuntary eye tremors and the impulse responses of ganglioncells. Based on the evaluation of the model, two hypotheses are formulated on the highlydebated role of involuntary eye tremors: 1 The role of involuntary eye tremors hasinformation theoretical implications 2 From an information processing point of view, thefunctional role of involuntary eye-movements extends to more than just the maintenance ofaction potentials. Involuntary eye-movements may be responsible for the compensation ofinformation losses caused by a non-overlapping receptive field architecture. In support ofthese hypotheses, the article provides a detailed analysis of the model's biologicalrelevance, along with numerical simulations and a hardware implementation.

  13. The effect of task difficulty on eye movement sequences in multiple dimensions

    NARCIS (Netherlands)

    Dewhurst, Richard; Nyström, Marcus; Jarodzka, Halszka; Foulsham, Tom; Johansson, Roger; Holmqvist, Kenneth

    2012-01-01

    Dewhurst, R., Nyström, M., Jarodzka, H., Foulsham, T., Johansson, R., & Holmqvist, K. (2012, May). The effect of task difficulty on eye movement sequences in multiple dimensions. Presentation at the Scandinavian Workshop on Applied Eye Tracking, Stockholm, Sweden.

  14. Rapid eye movement sleep behaviour disorder in patients with narcolepsy is associated with hypocretin-1 deficiency

    DEFF Research Database (Denmark)

    Knudsen, Stine; Gammeltoft, Steen; Jennum, Poul J

    2010-01-01

    variables were analysed in relation to cataplexy and hypocretin deficiency with uni- and multivariate logistic/linear regression models, controlling for possible rapid eye movement sleep behaviour disorder biasing factors (age, gender, disease duration, previous anti-cataplexy medication). Only hypocretin......Rapid eye movement sleep behaviour disorder is characterized by dream-enacting behaviour and impaired motor inhibition during rapid eye movement sleep. Rapid eye movement sleep behaviour disorder is commonly associated with neurodegenerative disorders, but also reported in narcolepsy with cataplexy....... Most narcolepsy with cataplexy patients lack the sleep-wake, and rapid eye movement sleep, motor-regulating hypocretin neurons in the lateral hypothalamus. In contrast, rapid eye movement sleep behaviour disorder and hypocretin deficiency are rare in narcolepsy without cataplexy. We hypothesized...

  15. Continuous Auditory Feedback of Eye Movements: An Exploratory Study toward Improving Oculomotor Control

    Directory of Open Access Journals (Sweden)

    Eric O. Boyer

    2017-04-01

    Full Text Available As eye movements are mostly automatic and overtly generated to attain visual goals, individuals have a poor metacognitive knowledge of their own eye movements. We present an exploratory study on the effects of real-time continuous auditory feedback generated by eye movements. We considered both a tracking task and a production task where smooth pursuit eye movements (SPEM can be endogenously generated. In particular, we used a visual paradigm which enables to generate and control SPEM in the absence of a moving visual target. We investigated whether real-time auditory feedback of eye movement dynamics might improve learning in both tasks, through a training protocol over 8 days. The results indicate that real-time sonification of eye movements can actually modify the oculomotor behavior, and reinforce intrinsic oculomotor perception. Nevertheless, large inter-individual differences were observed preventing us from reaching a strong conclusion on sensorimotor learning improvements.

  16. Eye movement responses to health messages on cigarette packages

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    TE Kessels Loes

    2012-07-01

    Full Text Available Abstract 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

  17. Eye movement prediction by oculomotor plant Kalman filter with brainstem control

    Institute of Scientific and Technical Information of China (English)

    Oleg V.KOMOGORTSEV; Javed I.KHAN

    2009-01-01

    Our work addresses one of the core issues related to Human Computer Interaction (HCI) systems that use eye gaze as an input.This issue is the sensor,transmission and other delays that exist in any eye tracker-based system,reducing its performance.A delay effect can be compensated by an accurate prediction of the eye movement trajectories.This paper introduces a mathematical model of the human eye that uses anatomical properties of the Human Visual System to predict eye movement trajectories.The eye mathematical model is transformed into a Kalman filter form to provide continuous eye position signal prediction during all eye movement types.The model presented in this paper uses brainstem control properties employed during transitions between fast (saccade) and slow (fixations,pursuit) eye movements.Results presented in this paper indicate that the proposed eye model in a Kalman filter form improves the accuracy of eye move-ment prediction and is capable of a real-time performance.In addition to the HCI systems with the direct eye gaze input,the proposed eye model can be immediately applied for a bit-rate/computational reduction in real-time gaze-contingent systems.

  18. Eye movement related brain responses to emotional scenes during free viewing

    Science.gov (United States)

    Simola, Jaana; Torniainen, Jari; Moisala, Mona; Kivikangas, Markus; Krause, Christina M.

    2013-01-01

    Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS). Brain responses to emotional stimuli were compared between serial and parallel presentation. An “emotional” set included one image with high positive or negative valence among neutral images. A “neutral” set comprised four neutral images. The participants were asked to indicate which picture—if any—was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs) were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP (“late positive potential”) amplitudes at 400–500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation. PMID:23970856

  19. Eye movement related brain responses to emotional scenes during free viewing

    Directory of Open Access Journals (Sweden)

    Jaana eSimola

    2013-08-01

    Full Text Available Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS. Brain responses to emotional stimuli were compared between serial and parallel presentation. An ‘emotional’ set included one image with high positive or negative valence among neutral images. A ‘neutral’ set comprised four neutral images. The participants were asked to indicate which picture - if any - was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP (‘late positive potential’ amplitudes at 400–500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results, however, did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation.

  20. Eye movement related brain responses to emotional scenes during free viewing.

    Science.gov (United States)

    Simola, Jaana; Torniainen, Jari; Moisala, Mona; Kivikangas, Markus; Krause, Christina M

    2013-01-01

    Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS). Brain responses to emotional stimuli were compared between serial and parallel presentation. An "emotional" set included one image with high positive or negative valence among neutral images. A "neutral" set comprised four neutral images. The participants were asked to indicate which picture-if any-was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs) were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP ("late positive potential") amplitudes at 400-500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation.

  1. Eye movements when reading text messaging (txt msgng).

    Science.gov (United States)

    Perea, Manuel; Acha, Joana; Carreiras, Manuel

    2009-08-01

    The growing popularity of mobile-phone technology has led to changes in the way people--particularly younger people--communicate. A clear example of this is the advent of Short Message Service (SMS) language, which includes orthographic abbreviations (e.g., omitting vowels, as in wk, week) and phonetic respelling (e.g., using u instead of you). In the present study, we examined the pattern of eye movements during reading of SMS sentences (e.g., my hols wr gr8), relative to normally written sentences, in a sample of skilled "texters". SMS sentences were created by using (mostly) orthographic or phonological abbreviations. Results showed that there is a reading cost--both at a local level and at a global level--for individuals who are highly expert in SMS language. Furthermore, phonological abbreviations resulted in a greater cost than orthographic abbreviations.

  2. Lexical Processes and Eye Movements in Neglect Dyslexia

    Directory of Open Access Journals (Sweden)

    Giuseppe di Pellegrino

    2002-01-01

    Full Text Available 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.

  3. Contextual override of pragmatic anomalies: evidence from eye movements.

    Science.gov (United States)

    Filik, Ruth

    2008-02-01

    Readers typically experience processing difficulty when they encounter a word that is anomalous within the local context, such as 'The mouse picked up the dynamite...'. The research reported here demonstrates that by placing a sentence in a fictional scenario that is already well known to the reader (e.g., a Tom and Jerry cartoon, as a context for the example sentence above), the difficulty usually associated with these pragmatic anomalies can be immediately eliminated, as reflected in participants' eye movement behaviour. This finding suggests that readers can rapidly integrate information from their common ground, specifically, their cultural knowledge, whilst interpreting incoming text, and provides further evidence that incoming words are immediately integrated within the global discourse.

  4. Cognition in rapid eye movement sleep behavior disorder

    Directory of Open Access Journals (Sweden)

    Jean-François eGagnon

    2012-05-01

    Full Text Available Rapid eye movement (REM sleep behavior disorder (RBD is a parasomnia characterized by excessive muscle activity and undesirable motor events during REM sleep. RBD occurs in approximately 0.5% of the general population, with a higher prevalence in older men. RBD is a frequent feature of dementia with Lewy bodies (DLB, but is only rarely reported in Alzheimer’s disease. RBD is also a risk factor for α-synuclein-related diseases, such as DLB, Parkinson’s disease (PD, and multiple system atrophy. Therefore, RBD has major implications for the diagnosis and treatment of neurodegenerative disorders and for understanding neurodegeneration mechanisms. Several markers of neurodegeneration have been identified in RBD, including cognitive impairments such as deficits in attention, executive functions, learning capacities, and visuospatial abilities. Approximately 50% of RBD patients present mild cognitive impairment (MCI. Moreover, RBD is also associated with cognitive decline in PD.

  5. Voluntary Saccadic Eye Movements Ride the Attentional Rhythm.

    Science.gov (United States)

    Hogendoorn, Hinze

    2016-10-01

    Visual perception seems continuous, but recent evidence suggests that the underlying perceptual mechanisms are in fact periodic-particularly visual attention. Because visual attention is closely linked to the preparation of saccadic eye movements, the question arises how periodic attentional processes interact with the preparation and execution of voluntary saccades. In two experiments, human observers made voluntary saccades between two placeholders, monitoring each one for the presentation of a threshold-level target. Detection performance was evaluated as a function of latency with respect to saccade landing. The time course of detection performance revealed oscillations at around 4 Hz both before the saccade at the saccade origin and after the saccade at the saccade destination. Furthermore, oscillations before and after the saccade were in phase, meaning that the saccade did not disrupt or reset the ongoing attentional rhythm. Instead, it seems that voluntary saccades are executed as part of an ongoing attentional rhythm, with the eyes in flight during the troughs of the attentional wave. This finding for the first time demonstrates that periodic attentional mechanisms affect not only perception but also overt motor behavior.

  6. Imagined motor action and eye movements in schizophrenia

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    Céline eDelerue

    2013-07-01

    Full Text Available 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.

  7. Eye and Hand Movements during Reconstruction of Spatial Memory

    Directory of Open Access Journals (Sweden)

    Melanie Rose Burke

    2012-05-01

    Full Text Available Recent behavioural and biological evidence indicates common mechanisms serving working memory and attention (eg, Awh et al 2006, Trends in Cognitive Sciences 10, 124–130. This study explored the role of spatial attention and visual search in an adapted Corsi spatial memory task. Eye movements and touch responses were recorded from participants who recalled locations (signalled by colour or shape change from an array presented either simultaneously or sequentially. The time delay between target presentation and recall (0, 5, or 10s and the number of locations to be remembered (2–5 were also manipulated. Analysis of the response phase revealed subjects were less accurate (touch data and fixated longer (eye data when responding to sequentially presented targets. Fixation duration was also influenced by whether spatial location was initially signalled by colour or shape change. We conclude that attention and temporal delays during retention of a target play a minor role in motor behaviour during a corsi spatial memory task. In contrast, the type of memory required (ie, location and/or memory and number of items plays a key role on subject performance and behaviour.

  8. Predicting rhesus monkey eye movements during natural-image search.

    Science.gov (United States)

    Segraves, Mark A; Kuo, Emory; Caddigan, Sara; Berthiaume, Emily A; Kording, Konrad P

    2017-03-01

    There are three prominent factors that can predict human visual-search behavior in natural scenes: the distinctiveness of a location (salience), similarity to the target (relevance), and features of the environment that predict where the object might be (context). We do not currently know how well these factors are able to predict macaque visual search, which matters because it is arguably the most popular model for asking how the brain controls eye movements. Here we trained monkeys to perform the pedestrian search task previously used for human subjects. Salience, relevance, and context models were all predictive of monkey eye fixations and jointly about as precise as for humans. We attempted to disrupt the influence of scene context on search by testing the monkeys with an inverted set of the same images. Surprisingly, the monkeys were able to locate the pedestrian at a rate similar to that for upright images. The best predictions of monkey fixations in searching inverted images were obtained by rotating the results of the model predictions for the original image. The fact that the same models can predict human and monkey search behavior suggests that the monkey can be used as a good model for understanding how the human brain enables natural-scene search.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2000-06-01

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

  11. The coeruleus/subcoeruleus complex in rapid eye movement sleep behaviour disorders in Parkinson's disease.

    Science.gov (United States)

    García-Lorenzo, Daniel; Longo-Dos Santos, Clarisse; Ewenczyk, Claire; Leu-Semenescu, Smaranda; Gallea, Cecile; Quattrocchi, Graziella; Pita Lobo, Patricia; Poupon, Cyril; Benali, Habib; Arnulf, Isabelle; Vidailhet, Marie; Lehericy, Stéphane

    2013-07-01

    In Parkinson's disease, rapid eye movement sleep behaviour disorder is an early non-dopaminergic syndrome with nocturnal violence and increased muscle tone during rapid eye movement sleep that can precede Parkinsonism by several years. The neuronal origin of rapid eye movement sleep behaviour disorder in Parkinson's disease is not precisely known; however, the locus subcoeruleus in the brainstem has been implicated as this structure blocks muscle tone during normal rapid eye movement sleep in animal models and can be damaged in Parkinson's disease. Here, we studied the integrity of the locus coeruleus/subcoeruleus complex in patients with Parkinson's disease using combined neuromelanin-sensitive, structural and diffusion magnetic resonance imaging approaches. We compared 24 patients with Parkinson's disease and rapid eye movement sleep behaviour disorder, 12 patients without rapid eye movement sleep behaviour disorder and 19 age- and gender-matched healthy volunteers. All subjects underwent clinical examination and characterization of rapid eye movement sleep using video-polysomnography and multimodal imaging at 3 T. Using neuromelanin-sensitive imaging, reduced signal intensity was evident in the locus coeruleus/subcoeruleus area in patients with Parkinson's disease that was more marked in patients with than those without rapid eye movement sleep behaviour disorder. Reduced signal intensity correlated with the percentage of abnormally increased muscle tone during rapid eye movement sleep. The results confirmed that this complex is affected in Parkinson's disease and showed a gradual relationship between damage to this structure, presumably the locus subcoeruleus, and abnormal muscle tone during rapid eye movement sleep, which is the cardinal marker of rapid eye movement sleep behaviour disorder. In longitudinal studies, the technique may also provide early markers of non-dopaminergic Parkinson's disease pathology to predict the occurrence of Parkinson's disease.

  12. Latency of saccadic eye movement during contraction of bilateral and unilateral shoulder girdle elevators.

    Science.gov (United States)

    Fujiwara, Katsuo; Kunita, Kenji; Toyama, Hiroshi

    2003-02-01

    We compared the timed latencies of saccadic eye movement during isometric contraction of the bilateral and unilateral shoulder girdle elevators in a sitting posture. Muscle contraction force was increased in 10% increments from 0% to 60% of the maximal voluntary contraction (MVC) of each side. Saccadic latency was measured as the latency to the beginning of eye movement toward the lateral target that was moved at random intervals in 20 degree amplitude jumps. Eye movement was measured using the electro-oculogram technique. During bilateral contraction, saccadic latency decreased until 30% MVC and then began to increase at 40% MVC. During unilateral contraction, saccadic latency decreased until 30% MVC in a similar pattern as in bilateral condition, was constant from 30% MVC to 50% MVC, followed by a slight increase at 60% MVC. The saccadic latencies at 10% and 40-60% MVC were significantly shorter during unilateral contraction than bilateral contraction. Thus, the relative force for producing a marked shortening of saccadic latency is observed within a wider range during unilateral contraction than bilateral contraction.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. The "hypnotic state" and eye movements: Less there than meets the eye?

    Science.gov (United States)

    Nordhjem, Barbara; Marcusson-Clavertz, David; Holmqvist, Kenneth

    2017-01-01

    Responsiveness to hypnotic procedures has been related to unusual eye behaviors for centuries. Kallio and collaborators claimed recently that they had found a reliable index for "the hypnotic state" through eye-tracking methods. Whether or not hypnotic responding involves a special state of consciousness has been part of a contentious debate in the field, so the potential validity of their claim would constitute a landmark. However, their conclusion was based on 1 highly hypnotizable individual compared with 14 controls who were not measured on hypnotizability. We sought to replicate their results with a sample screened for High (n = 16) or Low (n = 13) hypnotizability. We used a factorial 2 (high vs. low hypnotizability) x 2 (hypnosis vs. resting conditions) counterbalanced order design with these eye-tracking tasks: Fixation, Saccade, Optokinetic nystagmus (OKN), Smooth pursuit, and Antisaccade (the first three tasks has been used in Kallio et al.'s experiment). Highs reported being more deeply in hypnosis than Lows but only in the hypnotic condition, as expected. There were no significant main or interaction effects for the Fixation, OKN, or Smooth pursuit tasks. For the Saccade task both Highs and Lows had smaller saccades during hypnosis, and in the Antisaccade task both groups had slower Antisaccades during hypnosis. Although a couple of results suggest that a hypnotic condition may produce reduced eye motility, the lack of significant interactions (e.g., showing only Highs expressing a particular eye behavior during hypnosis) does not support the claim that eye behaviors (at least as measured with the techniques used) are an indicator of a "hypnotic state.” Our results do not preclude the possibility that in a more spontaneous or different setting the experience of being hypnotized might relate to specific eye behaviors. PMID:28846696

  15. Vestibulo-tactile interactions regarding motion perception and eye movements in yaw

    NARCIS (Netherlands)

    Bos, J.E.; Erp, J.B.F. van; Groen, E.L.; Veen, H.J. van

    2005-01-01

    This paper shows that tactile stimulation can override vestibular information regarding spinning sensations and eye movements. However, we conclude that the current data do not support the hypothesis that tactile stimulation controls eye movements directly. To this end, twenty-four subjects were pas

  16. Validity of Eye Movement Methods and Indices for Capturing Semantic (Associative) Priming Effects

    Science.gov (United States)

    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…

  17. How eye movements in EMDR work : Changes in memory vividness and emotionality

    NARCIS (Netherlands)

    Leer, Arne; Engelhard, Iris M.; Van Den Hout, Marcel A.

    2014-01-01

    Background and objectives Eye movements (EM) during recall of an aversive memory is a treatment element unique to Eye Movement Desensitization and Reprocessing (EMDR). Experimental studies have shown that EM reduce memory vividness and/or emotionality shortly after the intervention. However, it is

  18. Eye movements in patients with Whiplash Associated Disorders: A systematic review

    NARCIS (Netherlands)

    B.K. Ischebeck (B.); J. de Vries (Jurryt); J.N. van der Geest (Jos); M. Janssen (Malou); J.-P. van Wingerden (Jan-Paul); G.J. Kleinrensink (Gert Jan); M.A. Frens (Maarten)

    2016-01-01

    textabstractBackground: Many people with Whiplash Associated Disorders (WAD) report problems with vision, some of which may be due to impaired eye movements. Better understanding of such impaired eye movements could improve diagnostics and treatment strategies. This systematic review surveys the

  19. Showing a model's eye movements in examples does not improve learning of problem-solving tasks

    NARCIS (Netherlands)

    van Marlen, Tim; van Wermeskerken, Margot; Jarodzka, Halszka; van Gog, Tamara

    2016-01-01

    Eye movement modeling examples (EMME) are demonstrations of a computer-based task by a human model (e.g., a teacher), with the model's eye movements superimposed on the task to guide learners' attention. EMME have been shown to enhance learning of perceptual classification tasks; however, it is an

  20. Showing a model's eye movements in examples does not improve learning of problem-solving tasks

    NARCIS (Netherlands)

    van Marlen, Tim; van Wermeskerken, Margot; Jarodzka, Halszka; van Gog, Tamara

    2016-01-01

    Eye movement modeling examples (EMME) are demonstrations of a computer-based task by a human model (e.g., a teacher), with the model's eye movements superimposed on the task to guide learners' attention. EMME have been shown to enhance learning of perceptual classification tasks; however, it is an o

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

    Science.gov (United States)

    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…

  2. Vestibulo-tactile interactions regarding motion perception and eye movements in yaw

    NARCIS (Netherlands)

    Bos, J.E.; Erp, J.B.F. van; Groen, E.L.; Veen, H.J. van

    2005-01-01

    This paper shows that tactile stimulation can override vestibular information regarding spinning sensations and eye movements. However, we conclude that the current data do not support the hypothesis that tactile stimulation controls eye movements directly. To this end, twenty-four subjects were

  3. Exploring Cultural Variation in Eye Movements on a Web Page between Americans and Koreans

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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,…

  5. Origins of superior dynamic visual acuity in baseball players: superior eye movements or superior image processing.

    Directory of Open Access Journals (Sweden)

    Yusuke Uchida

    Full Text Available Dynamic visual acuity (DVA is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DVA in baseball players and non-athletes using moving Landolt rings in two conditions. In the first experiment, the participants were allowed to move their eyes (free-eye-movement conditions, whereas in the second they were required to fixate on a fixation target (fixation conditions. The athletes displayed significantly better DVA than the non-athletes in the free-eye-movement conditions. However, there was no significant difference between the groups in the fixation conditions. These results suggest that the better DVA of athletes is primarily due to an improved ability to track moving targets with their eyes, rather than to improved perception of moving images on the retina.

  6. Eye Movements and Road Hazard Detection: Effects of Blur and Distractors.

    Science.gov (United States)

    Lee, Samantha Sze-Yee; Black, Alex A; Lacherez, Philippe; Wood, Joanne M

    2016-09-01

    To examine the effects of optical blur, auditory distractors, and age on eye movement patterns while performing a driving hazard perception test (HPT). Twenty young (mean age 27.1 ± 4.6 years) and 20 older (73.3 ± 5.7 years) drivers with normal vision completed a HPT in a repeated-measures counterbalanced design while their eye movements were recorded. Testing was performed under two visual (best-corrected vision and with +2.00DS blur) and two distractor (with and without auditory distraction) conditions. Participants were required to respond to road hazards appearing in the HPT videos of real-world driving scenes and their hazard response times were recorded. Blur and distractors each significantly delayed hazard response time by 0.42 and 0.76 s, respectively (p < 0.05). A significant interaction between age and distractors indicated that older drivers were more affected by distractors than young drivers (response with distractors delayed by 0.96 and 0.60 s, respectively). There were no other two- or three-way interaction effects on response time. With blur, for example, both groups fixated significantly longer on hazards before responding compared to best-corrected vision. In the presence of distractors, both groups exhibited delayed first fixation on the hazards and spent less time fixating on the hazards. There were also significant differences in eye movement characteristics between groups, where older drivers exhibited smaller saccades, delayed first fixation on hazards, and shorter fixation duration on hazards compared to the young drivers. Collectively, the findings of delayed hazard response times and alterations in eye movement patterns with blur and distractors provide further evidence that visual impairment and distractors are independently detrimental to driving safety given that delayed hazard response times are linked to increased crash risk.

  7. Eye Movement Studies on Word Recognition%词汇识别的眼动研究

    Institute of Scientific and Technical Information of China (English)

    周永垒; 任桂琴

    2011-01-01

    As an immediate measuring method,eye movement recording can monitor the subjects' behavior dynamically.From the perspectives of lexicon accesses with or without various interpretations,this thesis reviewed eye movement studies on word recognition,especially on the role of orthography and phonology in word access and analyzed and compared different views on the role of sentence context and relative meaning frequency in lexical ambiguity resolution.Based on previous studies,this thesis commented on the eye movement study features of word recognition investigations and the problems to be studied.%作为一种即时测量的研究手段,眼动方法可以动态地、同步地监控被试的阅读行为。从歧义词通达与非歧义词通达两个角度出发,对词汇识别过程中形、音的作用以及词汇歧义消解过程中语境、相对频率的作用等问题上存在的不同观点进行对比分析。在此基础上,分析总结词汇识别的眼动研究特点及有待于研究的问题。

  8. Pursuit eye-movements in curve driving differentiate between future path and tangent point models.

    Directory of Open Access Journals (Sweden)

    Otto Lappi

    Full Text Available For nearly 20 years, looking at the tangent point on the road edge has been prominent in models of visual orientation in curve driving. It is the most common interpretation of the commonly observed pattern of car drivers looking through a bend, or at the apex of the curve. Indeed, in the visual science literature, visual orientation towards the inside of a bend has become known as "tangent point orientation". Yet, it remains to be empirically established whether it is the tangent point the drivers are looking at, or whether some other reference point on the road surface, or several reference points, are being targeted in addition to, or instead of, the tangent point. Recently discovered optokinetic pursuit eye-movements during curve driving can provide complementary evidence over and above traditional gaze-position measures. This paper presents the first detailed quantitative analysis of pursuit eye movements elicited by curvilinear optic flow in real driving. The data implicates the far zone beyond the tangent point as an important gaze target area during steady-state cornering. This is in line with the future path steering models, but difficult to reconcile with any pure tangent point steering model. We conclude that the tangent point steering models do not provide a general explanation of eye movement and steering during a curve driving sequence and cannot be considered uncritically as the default interpretation when the gaze position distribution is observed to be situated in the region of the curve apex.

  9. An eye movement based reading intervention in lexical and segmental readers with acquired dyslexia.

    Science.gov (United States)

    Ablinger, Irene; von Heyden, Kerstin; Vorstius, Christian; Halm, Katja; Huber, Walter; Radach, Ralph

    2014-01-01

    Due to their brain damage, aphasic patients with acquired dyslexia often rely to a greater extent on lexical or segmental reading procedures. Thus, therapy intervention is mostly targeted on the more impaired reading strategy. In the present work we introduce a novel therapy approach based on real-time measurement of patients' eye movements as they attempt to read words. More specifically, an eye movement contingent technique of stepwise letter de-masking was used to support sequential reading, whereas fixation-dependent initial masking of non-central letters stimulated a lexical (parallel) reading strategy. Four lexical and four segmental readers with acquired central dyslexia received our intensive reading intervention. All participants showed remarkable improvements as evident in reduced total reading time, a reduced number of fixations per word and improved reading accuracy. Both types of intervention led to item-specific training effects in all subjects. A generalisation to untrained items was only found in segmental readers after the lexical training. Eye movement analyses were also used to compare word processing before and after therapy, indicating that all patients, with one exclusion, maintained their preferred reading strategy. However, in several cases the balance between sequential and lexical processing became less extreme, indicating a more effective individual interplay of both word processing routes.

  10. Anticipatory eye movements and long-term memory in early infancy.

    Science.gov (United States)

    Wong-Kee-You, Audrey M B; Adler, Scott A

    2016-11-01

    Advances in our understanding of long-term memory in early infancy have been made possible by studies that have used the Rovee-Collier's mobile conjugate reinforcement paradigm and its variants. One function that has been attributed to long-term memory is the formation of expectations (Rovee-Collier & Hayne, 1987); consequently, a long-term memory representation should be established during expectation formation. To examine this prediction and potentially open the door on a new paradigm for exploring infants' long-term memory, using the Visual Expectation Paradigm (Haith, Hazan, & Goodman, 1988), 3-month-old infants were trained to form an expectation for predictable color and spatial information of picture events and emit anticipatory eye movements to those events. One day later, infants' anticipatory eye movements decreased in number relative to the end of training when the predictable colors were changed but not when the spatial location of the predictable color events was changed. These findings confirm that information encoded during expectation formation are stored in long-term memory, as hypothesized by Rovee-Collier and colleagues. Further, this research suggests that eye movements are potentially viable measures of long-term memory in infancy, providing confirmatory evidence for early mnemonic processes. © 2016 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    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…

  12. Tracking Students' Cognitive Processes during Program Debugging--An Eye-Movement Approach

    Science.gov (United States)

    Lin, Yu-Tzu; Wu, Cheng-Chih; Hou, Ting-Yun; Lin, Yu-Chih; Yang, Fang-Ying; Chang, Chia-Hu

    2016-01-01

    This study explores students' cognitive processes while debugging programs by using an eye tracker. Students' eye movements during debugging were recorded by an eye tracker to investigate whether and how high- and low-performance students act differently during debugging. Thirty-eight computer science undergraduates were asked to debug two C…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  15. Bilateral saccadic eye movements and tactile stimulation, but not auditory stimulation, enhance memory retrieval

    NARCIS (Netherlands)

    Nieuwenhuis, S.; Elzinga, B.M.; Ras, P.H.; Berends, F.; Duijs, P.; Samara, Z.; Slagter, H.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 rapi

  16. Isolating Discriminant Neural Activity in the Presence of Eye Movements and Concurrent Task Demands

    Directory of Open Access Journals (Sweden)

    Jon Touryan

    2017-07-01

    Full Text Available A growing number of studies use the combination of eye-tracking and electroencephalographic (EEG measures to explore the neural processes that underlie visual perception. In these studies, fixation-related potentials (FRPs are commonly used to quantify early and late stages of visual processing that follow the onset of each fixation. However, FRPs reflect a mixture of bottom-up (sensory-driven and top-down (goal-directed processes, in addition to eye movement artifacts and unrelated neural activity. At present there is little consensus on how to separate this evoked response into its constituent elements. In this study we sought to isolate the neural sources of target detection in the presence of eye movements and over a range of concurrent task demands. Here, participants were asked to identify visual targets (Ts amongst a grid of distractor stimuli (Ls, while simultaneously performing an auditory N-back task. To identify the discriminant activity, we used independent components analysis (ICA for the separation of EEG into neural and non-neural sources. We then further separated the neural sources, using a modified measure-projection approach, into six regions of interest (ROIs: occipital, fusiform, temporal, parietal, cingulate, and frontal cortices. Using activity from these ROIs, we identified target from non-target fixations in all participants at a level similar to other state-of-the-art classification techniques. Importantly, we isolated the time course and spectral features of this discriminant activity in each ROI. In addition, we were able to quantify the effect of cognitive load on both fixation-locked potential and classification performance across regions. Together, our results show the utility of a measure-projection approach for separating task-relevant neural activity into meaningful ROIs within more complex contexts that include eye movements.

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

    Science.gov (United States)

    Eibenberger, Karin; Eibenberger, Bernhard; Rucci, Michele

    2016-08-01

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

  18. Breaking object correspondence across saccadic eye movements deteriorates object recognition

    Directory of Open Access Journals (Sweden)

    Christian H. Poth

    2015-12-01

    Full Text Available Visual perception is based on information processing during periods of eye fixations that are interrupted by fast saccadic eye movements. The ability to sample and relate information on task-relevant objects across fixations implies that correspondence between presaccadic and postsaccadic objects is established. Postsaccadic object information usually updates and overwrites information on the corresponding presaccadic object. The presaccadic object representation is then lost. In contrast, the presaccadic object is conserved when object correspondence is broken. This helps transsaccadic memory but it may impose attentional costs on object recognition. Therefore, we investigated how breaking object correspondence across the saccade affects postsaccadic object recognition. In Experiment 1, object correspondence was broken by a brief postsaccadic blank screen. Observers made a saccade to a peripheral object which was displaced during the saccade. This object reappeared either immediately after the saccade or after the blank screen. Within the postsaccadic object, a letter was briefly presented (terminated by a mask. Observers reported displacement direction and letter identity in different blocks. Breaking object correspondence by blanking improved displacement identification but deteriorated postsaccadic letter recognition. In Experiment 2, object correspondence was broken by changing the object’s contrast-polarity. There were no object displacements and observers only reported letter identity. Again, breaking object correspondence deteriorated postsaccadic letter recognition. These findings identify transsaccadic object correspondence as a key determinant of object recognition across the saccade. This is in line with the recent hypothesis that breaking object correspondence results in separate representations of presaccadic and postsaccadic objects which then compete for limited attentional processing resources (Schneider, 2013. Postsaccadic

  19. Experimental and computational analysis of monkey smooth pursuit eye movements.

    Science.gov (United States)

    Churchland, M M; Lisberger, S G

    2001-08-01

    Smooth pursuit eye movements are guided by visual feedback and are surprisingly accurate despite the time delay between visual input and motor output. Previous models have reproduced the accuracy of pursuit either by using elaborate visual signals or by adding sources of motor feedback. Our goal was to constrain what types of signals drive pursuit by obtaining data that would discriminate between these two modeling approaches, represented by the "image motion model" and the "tachometer feedback" model. Our first set of experiments probed the visual properties of pursuit with brief square-pulse and sine-wave perturbations of target velocity. Responses to pulse perturbations increased almost linearly with pulse amplitude, while responses to sine wave perturbations showed strong saturation with increasing stimulus amplitude. The response to sine wave perturbations was strongly dependent on the baseline image velocity at the time of the perturbation. Responses were much smaller if baseline image velocity was naturally large, or was artificially increased by superimposing sine waves on pulse perturbations. The image motion model, but not the tachometer feedback model, could reproduce these features of pursuit. We used a revision of the image motion model that was, like the original, sensitive to both image velocity and image acceleration. Due to a saturating nonlinearity, the sensitivity to image acceleration declined with increasing image velocity. Inclusion of this nonlinearity was motivated by our experimental results, was critical in accounting for the responses to perturbations, and provided an explanation for the unexpected stability of pursuit in the presence of perturbations near the resonant frequency. As an emergent property, the revised image motion model was able to reproduce the frequency and damping of oscillations recorded during artificial feedback delays. Our second set of experiments replicated prior recordings of pursuit responses to multiple

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

    Science.gov (United States)

    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. © The Author(s) 2016.

  1. Free Instrument for Movement Measure

    CERN Document Server

    Peña, Norberto; Corrêa, Lorena Peixoto Nogueira Rodriguez Martinez Salles; França, Lucas Gabriel Souza; Cunha, Marcelo do Vale; de Sousa, Marcos Cavalcanti; Vieira, João Paulo Bomfim Cruz; Miranda, José Garcia Vivas

    2013-01-01

    This paper presents the validation of a computational tool that serves to obtain continuous measurements of moving objects. The software uses techniques of computer vision, pattern recognition and optical flow, to enable tracking of objects in videos, generating data trajectory, velocity, acceleration and angular movement. The program was applied to track a ball around a simple pendulum. The methodology used to validate it, taking as a basis to compare the values measured by the program, as well as the theoretical values expected according to the model of a simple pendulum. The experiment is appropriate to the method because it was built within the limits of the linear harmonic oscillator and energy losses due to friction had been minimized, making it the most ideal possible. The results indicate that the tool is sensitive and accurate. Deviations of less than a millimeter to the extent of the trajectory, ensures the applicability of the software on physics, whether in research or in teaching topics.

  2. Basal ganglia neuronal activity during scanning eye movements in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Tomáš Sieger

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

  3. The Effect of Viscosity of PDMS Based Silicone-Oil Tamponade Agents on the Movement Relative to the Eye Wall during Eye Movements

    Directory of Open Access Journals (Sweden)

    Chan Yau Kei

    2011-05-01

    Full Text Available Silicone oil tamponade is used as vitreous substitute to treat complicated retinal diseases. It provides support to the retina and acts against contraction of the retina and as such plays a vital role in preventing eyes from certain blindness. Silicone oil however has a tendency to emulsify and is accountable to inflammation and glaucoma. In in-vitro study, it was found that using silicone-oil with higher viscosity reduce the occurrences of emulsifications. In this study, an eye model chamber was used to capture the movement of silicone oil bubbles inside the model eye chamber by rapid serial photography. A few tamponades derived from the same material but with different shear viscosities were used. Our objective of this experiment is to investigate the effect of viscosity of tamponade to the movement of tamponade relative to retinal phase in model eye chambers mimicking saccadic eye movements. Our experiment confirms that shear viscosity determines the relative movement between the silicone bubble and the chamber wall. The higher the viscosity, the smaller the movement of tamponade relative to the chamber wall. We suggested that using much viscous tamponade may reduce the onset of emulsification due to the reduction of relative movement.

  4. Dopamine transporter imaging in rapid eye movement sleep behavior disorder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Kyeong; Yoon, In Young; Kim, Jong Min; Jeong, Seok Hoon; Kim, Ji Sun; Lee, Byung Chul; Lee, Won Woo; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    The pathogenesis of rapid eye movement (REM) sleep behavior disorder (RBD) is still unknown. However, involvement of dopaminergic system in RBD has been hypothesized because of frequent association with degenerative movement disorders such as Parkinson's disease. The purpose of this study was to examine the extent and pattern of loss of dopamine transporter in RBD using FP-CIT SPECT. Fourteen patient with idiopathic RBD (mean age:665 yrs, M:F=10:3) participated in this study. Polysonmography confirmed loss of REM atonia and determined RBD severities by amount of tonic/phasic muscle activity during REM sleep in all cases. To compare with RBD, 14 early idiopathic Parkinson's disease rated as Hoehn and Yahr stage 1 (IPD) and 12 healthy controls were also selected. All participants performed single-photon emission computed tomography (SPECT) imaging 3 hours after injection of [123I]FP-CIT. Regions of interest were drawn on bilateral caudate and putamen, whole striatum and occipital cortex. Specific binding for dopamine transporters (DAT) were calculated using region to occipital uptake ratio based on the transient equilibrium method. Overall mean of DAT density in the striatum was lower in RBD group than controls, and higher than IPD group, However, DAT density in most individual RBD was still within normal range, and total striatal DAT density was not correlated with severity of RBD. Meanwhile, the caudate to putamen uptake ratio (C/P ratio) in RBD group was insignificantly higher than those in healthy controls. Nevertheless, C/P ratio within RBD group was reversely correlated with the RBD severity. Our study suggested that nigrostriatal dopaminergic degeneration could be a part of the pathogenesis of RBD, but not essential for the development of RBD. Further longitudinal evaluation of presynaptic dopaminergic system in idiopathic RBD may guarantee the more understanding for RBD and associated neurodegenerative disease.

  5. The categories, frequencies, and stability of idiosyncratic eye-movement patterns to faces.

    Science.gov (United States)

    Arizpe, Joseph; Walsh, Vincent; Yovel, Galit; Baker, Chris I

    2016-12-16

    The spatial pattern of eye-movements to faces considered typical for neurologically healthy individuals is a roughly T-shaped distribution over the internal facial features with peak fixation density tending toward the left eye (observer's perspective). However, recent studies indicate that striking deviations from this classic pattern are common within the population and are highly stable over time. The classic pattern actually reflects the average of these various idiosyncratic eye-movement patterns across individuals. The natural categories and respective frequencies of different types of idiosyncratic eye-movement patterns have not been specifically investigated before, so here we analyzed the spatial patterns of eye-movements for 48 participants to estimate the frequency of different kinds of individual eye-movement patterns to faces in the normal healthy population. Four natural clusters were discovered such that approximately 25% of our participants' fixation density peaks clustered over the left eye region (observer's perspective), 23% over the right eye-region, 31% over the nasion/bridge region of the nose, and 20% over the region spanning the nose, philthrum, and upper lips. We did not find any relationship between particular idiosyncratic eye-movement patterns and recognition performance. Individuals' eye-movement patterns early in a trial were more stereotyped than later ones and idiosyncratic fixation patterns evolved with time into a trial. Finally, while face inversion strongly modulated eye-movement patterns, individual patterns did not become less distinct for inverted compared to upright faces. Group-averaged fixation patterns do not represent individual patterns well, so exploration of such individual patterns is of value for future studies of visual cognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Human regional cerebral blood flow during rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Holm, S; Vorstrup, S;

    1991-01-01

    Owing to the coupling between CBF and neuronal activity, regional CBF is a reflection of neural activity in different brain regions. In this study we measured regional CBF during polysomnographically well-defined rapid-eye-movement (REM) sleep by the use of single photon emission computerized...... tomography and the new tracer 99mTc-dl-hexamethylpropyleneamine. Eleven healthy volunteers aged between 22 and 27 years were studied. CBF was measured on separate nights during REM sleep and during EEG-verified wakefulness. On awakening from REM sleep, all subjects reported visual dreams. During REM sleep...

  7. Eye movement desensitization and reprocessing for adolescent depression.

    Science.gov (United States)

    Bae, Hwallip; Kim, Daeho; Park, Yong Chon

    2008-03-01

    While cognitive behavior therapy is considered to be the first-line therapy for adolescent depression, there are limited data on whether other psychotherapeutic techniques are also effective in treating adolescents with depression. This report suggests the potential application of eye movement desensitization and reprocessing (EMDR) for treatment of depressive disorder related, not to trauma, but to stressful life events. At present, EMDR has only been empirically validated for only trauma-related disorders such as posttraumatic stress disorder. Two teenagers with major depressive disorder (MDD) underwent three and seven sessions of EMDR aimed at memories of stressful life events. After treatment, their depressive symptoms decreased to the level of full remission, and the therapeutic gains were maintained after two and three months of follow up. The effectiveness of EMDR for depression is explained by the model of adaptive information processing. Given the powerful effects observed within a brief period of time, the authors suggest that further investigation of EMDR for depressive disorders is warranted.

  8. Exploring the Relationship Between Eye Movements and Electrocardiogram Interpretation Accuracy

    Science.gov (United States)

    Davies, Alan; Brown, Gavin; Vigo, Markel; Harper, Simon; Horseman, Laura; Splendiani, Bruno; Hill, Elspeth; Jay, Caroline

    2016-12-01

    Interpretation of electrocardiograms (ECGs) is a complex task involving visual inspection. This paper aims to improve understanding of how practitioners perceive ECGs, and determine whether visual behaviour can indicate differences in interpretation accuracy. A group of healthcare practitioners (n = 31) who interpret ECGs as part of their clinical role were shown 11 commonly encountered ECGs on a computer screen. The participants’ eye movement data were recorded as they viewed the ECGs and attempted interpretation. The Jensen-Shannon distance was computed for the distance between two Markov chains, constructed from the transition matrices (visual shifts from and to ECG leads) of the correct and incorrect interpretation groups for each ECG. A permutation test was then used to compare this distance against 10,000 randomly shuffled groups made up of the same participants. The results demonstrated a statistically significant (α  0.05) result in 5 of the 11 stimuli demonstrating that the gaze shift between the ECG leads is different between the groups making correct and incorrect interpretations and therefore a factor in interpretation accuracy. The results shed further light on the relationship between visual behaviour and ECG interpretation accuracy, providing information that can be used to improve both human and automated interpretation approaches.

  9. Neuregulin-1 genotypes and eye movements in schizophrenia

    DEFF Research Database (Denmark)

    Haraldsson, H.M.; Ettinger, U.; Magnusdottir, B.B.;

    2010-01-01

    Neuregulin-1 (NRG-1) is a putative susceptibility gene for schizophrenia but the neurocognitive processes that may involve NRG-1 in schizophrenia are unknown. Deficits in antisaccade (AS) and smooth pursuit eye movements (SPEM) are promising endophenotypes, which may be associated with brain dysf...... performance. However, the power of the sample to identify small effects is limited and the possibility of a type II error must be kept in mind. Larger samples may be needed to reliably investigate such gene effects on oculomotor endophenotypes...... dysfunctions underlying the pathophysiology of schizophrenia. The aim of this study was to investigate the associations of NRG-1 genotypes with AS and SPEM in schizophrenia patients and healthy controls. Patients (N = 113) and controls (N = 106) were genotyped for two NRG-1 single nucleotide polymorphisms...... (SNPs); SNP8NRG222662, a surrogate marker for the originally described Icelandic NRG-1 risk haplotype, and SNP8NRG243177, which has recently been associated with individual differences in brain function. Subjects underwent infrared oculographic assessment of AS and SPEM. The study replicates previous...

  10. Treatment of Intrusive Suicidal Imagery Using Eye Movements

    Directory of Open Access Journals (Sweden)

    Jaël S. van Bentum

    2017-06-01

    Full Text Available Suicide and suicidal behavior are major public health concerns, and affect 3–9% of the population worldwide. Despite increased efforts for national suicide prevention strategies, there are still few effective interventions available for reducing suicide risk. In this article, we describe various theoretical approaches for suicide ideation and behavior, and propose to examine the possible effectiveness of a new and innovative preventive strategy. A model of suicidal intrusion (mental imagery related to suicide, also referred to as suicidal flash-forwards is presented describing one of the assumed mechanisms in the etiology of suicide and the mechanism of therapeutic change. We provide a brief rationale for an Eye Movement Dual Task (EMDT treatment for suicidal intrusions, describing techniques that can be used to target these suicidal mental images and thoughts to reduce overall behavior. Based on the available empirical evidence for the mechanisms of suicidal intrusions, this approach appears to be a promising new treatment to prevent suicidal behavior as it potentially targets one of the linking pins between suicidal ideation and suicidal actions.

  11. Continuous perception of motion and shape across saccadic eye movements.

    Science.gov (United States)

    Fracasso, Alessio; Caramazza, Alfonso; Melcher, David

    2010-11-24

    Although our naïve experience of visual perception is that it is smooth and coherent, the actual input from the retina involves brief and discrete fixations separated by saccadic eye movements. This raises the question of whether our impression of stable and continuous vision is merely an illusion. To test this, we examined whether motion perception can "bridge" a saccade in a two-frame apparent motion display in which the two frames were separated by a saccade. We found that transformational apparent motion, in which an object is seen to change shape and even move in three dimensions during the motion trajectory, continues across saccades. Moreover, participants preferred an interpretation of motion in spatial, rather than retinal, coordinates. The strength of the motion percept depended on the temporal delay between the two motion frames and was sufficient to give rise to a motion-from-shape aftereffect, even when the motion was defined by a second-order shape cue ("phantom transformational apparent motion"). These findings suggest that motion and shape information are integrated across saccades into a single, coherent percept of a moving object.

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

    Science.gov (United States)

    Benatar, Ashley; Clifton, Charles

    2014-02-01

    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.

  13. Desensitizing Addiction : Using Eye Movements to Reduce the Intensity of Substance-Related Mental Imagery and Craving

    NARCIS (Netherlands)

    Littel, M.; van den Hout, M.A.; Engelhard, I.M.

    2016-01-01

    Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During this treatment, patients recall traumatic memories while making horizontal eye movements (EM). Studies have shown that EM not only desensitize negative memories but also positive

  14. Desensitizing Addiction : Using Eye Movements to Reduce the Intensity of Substance-Related Mental Imagery and Craving

    NARCIS (Netherlands)

    Littel, M.; van den Hout, M.A.; Engelhard, I.M.

    2016-01-01

    Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder. During this treatment, patients recall traumatic memories while making horizontal eye movements (EM). Studies have shown that EM not only desensitize negative memories but also positive

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

    Science.gov (United States)

    Hedley, Darren; Young, Robyn; Brewer, Neil

    2012-10-01

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

  16. In your eyes only: deficits in executive functioning after frontal TMS reflect in eye movements.

    Science.gov (United States)

    Lüthi, Mathias; Henke, Katharina; Gutbrod, Klemens; Nyffeler, Thomas; Chaves, Silvia; Müri, René M

    2014-01-01

    This study investigated the roles of the right and left dorsolateral prefrontal (rDLPFC, lDLPFC) and the medial frontal cortex (MFC) in executive functioning using a theta burst transcranial magnetic stimulation (TMS) approach. Healthy subjects solved two visual search tasks: a number search task with low cognitive demands, and a number and letter search task with high cognitive demands. To observe how subjects solved the tasks, we assessed their behavior with and without TMS using eye movements when subjects were confronted with specific executive demands. To observe executive functions, we were particularly interested in TMS-induced changes in visual exploration strategies found to be associated with good or bad performance in a control condition without TMS stimulation. TMS left processing time unchanged in both tasks. Inhibition of the rDLPFC resulted in a decrease in anticipatory fixations in the number search task, i.e., a decrease in a good strategy in this low demand task. This was paired with a decrease in stimulus fixations. Together, these results point to a role of the rDLPFC in planning and response selection. Inhibition of the lDLPFC and the MFC resulted in an increase in anticipatory fixations in the number and letter search task, i.e., an increase in the application of a good strategy in this task. We interpret these results as a compensatory strategy to account for TMS-induced deficits in attentional switching when faced with high switching demands. After inhibition of the lDLPFC, an increase in regressive fixations was found in the number and letter search task. In the context of high working memory demands, this strategy appears to support TMS-induced working memory deficits. Combining an experimental TMS approach with the recording of eye movements proved sensitive to discrete decrements of executive functions and allows pinpointing the functional organization of the frontal lobes.

  17. Spatiotemporal Filter for Visual Motion Integration from Pursuit Eye Movements in Humans and Monkeys.

    Science.gov (United States)

    Mukherjee, Trishna; Liu, Bing; Simoncini, Claudio; Osborne, Leslie C

    2017-02-08

    Despite the enduring interest in motion integration, a direct measure of the space-time filter that the brain imposes on a visual scene has been elusive. This is perhaps because of the challenge of estimating a 3D function from perceptual reports in psychophysical tasks. We take a different approach. We exploit the close connection between visual motion estimates and smooth pursuit eye movements to measure stimulus-response correlations across space and time, computing the linear space-time filter for global motion direction in humans and monkeys. Although derived from eye movements, we find that the filter predicts perceptual motion estimates quite well. To distinguish visual from motor contributions to the temporal duration of the pursuit motion filter, we recorded single-unit responses in the monkey middle temporal cortical area (MT). We find that pursuit response delays are consistent with the distribution of cortical neuron latencies and that temporal motion integration for pursuit is consistent with a short integration MT subpopulation. Remarkably, the visual system appears to preferentially weight motion signals across a narrow range of foveal eccentricities rather than uniformly over the whole visual field, with a transiently enhanced contribution from locations along the direction of motion. We find that the visual system is most sensitive to motion falling at approximately one-third the radius of the stimulus aperture. Hypothesizing that the visual drive for pursuit is related to the filtered motion energy in a motion stimulus, we compare measured and predicted eye acceleration across several other target forms.SIGNIFICANCE STATEMENT A compact model of the spatial and temporal processing underlying global motion perception has been elusive. We used visually driven smooth eye movements to find the 3D space-time function that best predicts both eye movements and perception of translating dot patterns. We found that the visual system does not appear to use

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

    Science.gov (United States)

    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…

  19. Constraining eye movement when redirecting walking trajectories alters turning control in healthy young adults.

    Science.gov (United States)

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

    2013-05-01

    Humans use a specific steering synergy, where the eyes and head lead rotation to the new direction, when executing a turn or change in direction. Increasing evidence suggests that eye movement is critical for turning control and that when the eyes are constrained, or participants have difficulties making eye movements, steering control is disrupted. The purpose of the current study was to extend previous research regarding eye movements and steering control to a functional walking and turning task. This study investigated eye, head, trunk, and pelvis kinematics of healthy young adults during a 90° redirection of walking trajectory under two visual conditions: Free Gaze (the eyes were allowed to move naturally in the environment), and Fixed Gaze (participants were required to fixate the eyes on a target in front). Results revealed significant differences in eye, head, and trunk coordination between Free Gaze and Fixed Gaze conditions (p segments moved together with no significant differences between segment onset times. In addition, the sequence of segment rotation during Fixed Gaze suggested a bottom-up postural perturbation control strategy in place of top-down steering control seen in Free Gaze. The results of this study support the hypothesis that eye movement is critical for the release of the steering synergy for turning control.

  20. Post-saccadic oscillations in eye movement data recorded with pupil-based eye trackers reflect motion of the pupil inside the iris.

    Science.gov (United States)

    Nyström, Marcus; Hooge, Ignace; Holmqvist, Kenneth

    2013-11-01

    Current video eye trackers use information about the pupil center to estimate orientation and movement of the eye. While dual Purkinje eye trackers suffer from lens wobble and scleral search coils may be influenced by contact lens slippage directly after saccades, it is not known whether pupil-based eye trackers produces similar artifacts in the data. We recorded eye movements from participants making repetitive, horizontal saccades and compared the movement in the data with pupil- and iris movements extracted from the eye images. Results showed that post-saccadic instabilities clearly exist in data recorded with a pupil-based eye tracker. They also exhibit a high degree of reproducibility across saccades and within participants. While the recorded eye movement data correlated well with the movement of the pupil center, the iris center showed only little post-saccadic movement. This means that the pupil moves relative to the iris during post-saccadic eye movements, and that the eye movement data reflect pupil movement rather than eyeball rotation. Besides introducing inaccuracies and additional variability in the data, the pupil movement inside the eyeball influences the decision of when a saccade should end and the subsequent fixation should begin, and consequently higher order analyses based on fixations and saccades.

  1. Eye movements as an index of pathologist visual expertise: a pilot study.

    Directory of Open Access Journals (Sweden)

    Tad T Brunyé

    Full Text Available A pilot study examined the extent to which eye movements occurring during interpretation of digitized breast biopsy whole slide images (WSI can distinguish novice interpreters from experts, informing assessments of competency progression during training and across the physician-learning continuum. A pathologist with fellowship training in breast pathology interpreted digital WSI of breast tissue and marked the region of highest diagnostic relevance (dROI. These same images were then evaluated using computer vision techniques to identify visually salient regions of interest (vROI without diagnostic relevance. A non-invasive eye tracking system recorded pathologists' (N = 7 visual behavior during image interpretation, and we measured differential viewing of vROIs versus dROIs according to their level of expertise. Pathologists with relatively low expertise in interpreting breast pathology were more likely to fixate on, and subsequently return to, diagnostically irrelevant vROIs relative to experts. Repeatedly fixating on the distracting vROI showed limited value in predicting diagnostic failure. These preliminary results suggest that eye movements occurring during digital slide interpretation can characterize expertise development by demonstrating differential attraction to diagnostically relevant versus visually distracting image regions. These results carry both theoretical implications and potential for monitoring and evaluating student progress and providing automated feedback and scanning guidance in educational settings.

  2. Eye-Movement Patterns and Reader Characteristics of Students with Good and Poor Performance When Reading Scientific Text with Diagrams

    Science.gov (United States)

    Jian, Yu-Cin

    2017-01-01

    This study investigated the cognitive processes and reader characteristics of sixth graders who had good and poor performance when reading scientific text with diagrams. We first measured the reading ability and reading self-efficacy of sixth-grade participants, and then recorded their eye movements while they were reading an illustrated…

  3. Prolonged Exposure versus Eye Movement Desensitization and Reprocessing (EMDR) for PTSD rape victims.

    Science.gov (United States)

    Rothbaum, Barbara Olasov; Astin, Millie C; Marsteller, Fred

    2005-12-01

    This controlled study evaluated the relative efficacy of Prolonged Exposure (PE) and Eye Movement Desensitization and Reprocessing (EMDR) compared to a no-treatment wait-list control (WAIT) in the treatment of PTSD in adult female rape victims (n = 74). Improvement in PTSD as assessed by blind independent assessors, depression, dissociation, and state anxiety was significantly greater in both the PE and EMDR group than the WAIT group (n = 20 completers per group). PE and EMDR did not differ significantly for change from baseline to either posttreatment or 6-month follow-up measurement for any quantitative scale.

  4. Co-registration of Eye Movements and Event-Related Potentials in Connected-Text Paragraph Reading

    Directory of Open Access Journals (Sweden)

    John M Henderson

    2013-07-01

    Full Text Available Eyetracking during reading has provided a critical source of on-line behavioral data informing basic theory in language processing. Similarly, event-related potentials have provided an important on-line measure of the neural correlates of language processing. Recently there has been strong interest in co-registering eyetracking and ERPs from simultaneous recording to capitalize on the strengths of both techniques, but a challenge has been devising approaches for controlling artifacts produced by eye movements in the EEG waveform. In this paper we describe our approach to correcting for eye movements in EEG and demonstrate its applicability to reading. The method is based on independent components analysis, and uses three criteria for identifying components tied to saccades: (1 component loadings on the surface of the head are consistent with eye movements; (2 source analysis localizes component activity to the eyes, and (3 the temporal activation of the component occurred at the time of the eye movement and differed for right and left eye movements. We demonstrate this method’s applicability to reading by comparing ERPs time-locked to fixation onset in two reading conditions. In the text-reading condition, participants read paragraphs of text. In the pseudo-reading control condition, participants moved their eyes through spatially similar pseudo-text that preserved word locations, word shapes, and paragraph spatial structure, but eliminated meaning. The corrected EEG, time-locked to fixation onsets, showed effects of reading condition in early ERP components. The results indicate that co-registration of eyetracking and EEG in connected-text paragraph reading is possible, and has the potential to become an important tool for investigating the cognitive and neural bases of on-line language processing in reading.

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

    Science.gov (United States)

    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. © 2015. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

    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…

  7. Worth a glance: Using eye movements to investigate the cognitive neuroscience of memory.

    Directory of Open Access Journals (Sweden)

    Deborah E Hannula

    2010-10-01

    Full Text Available Results of several investigations indicate that eye movements can reveal memory for elements of previous experience. These effects of memory on eye movement behavior can emerge very rapidly, changing the efficiency and even the nature of visual processing without appealing to verbal reports and without requiring conscious recollection. This aspect of eye-movement based memory investigations is particularly useful when eye movement methods are used with special populations (e.g., young children, elderly individuals, and patients with severe amnesia, and also permits use of comparable paradigms in animals and humans, helping to bridge different memory literatures and permitting cross-species generalizations. Unique characteristics of eye movement methods have produced findings that challenge long-held views about the nature of memory, its organization in the brain, and its failures in special populations. Recently, eye movement methods have been successfully combined with neuroimaging techniques such as fMRI, single-unit recording, and MEG, permitting more sophisticated investigations of memory. Ultimately, combined use of eye-tracking with neuropsychological and neuroimaging methods promises to provide a more comprehensive account of brain-behavior relationships and adheres to the “converging evidence” approach to cognitive neuroscience.

  8. Worth a glance: using eye movements to investigate the cognitive neuroscience of memory.

    Science.gov (United States)

    Hannula, Deborah E; Althoff, Robert R; Warren, David E; Riggs, Lily; Cohen, Neal J; Ryan, Jennifer D

    2010-01-01

    Results of several investigations indicate that eye movements can reveal memory for elements of previous experience. These effects of memory on eye movement behavior can emerge very rapidly, changing the efficiency and even the nature of visual processing without appealing to verbal reports and without requiring conscious recollection. This aspect of eye movement based memory investigations is particularly useful when eye movement methods are used with special populations (e.g., young children, elderly individuals, and patients with severe amnesia), and also permits use of comparable paradigms in animals and humans, helping to bridge different memory literatures and permitting cross-species generalizations. Unique characteristics of eye movement methods have produced findings that challenge long-held views about the nature of memory, its organization in the brain, and its failures in special populations. Recently, eye movement methods have been successfully combined with neuroimaging techniques such as fMRI, single-unit recording, and magnetoencephalography, permitting more sophisticated investigations of memory. Ultimately, combined use of eye-tracking with neuropsychological and neuroimaging methods promises to provide a more comprehensive account of brain-behavior relationships and adheres to the "converging evidence" approach to cognitive neuroscience.

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

    Science.gov (United States)

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

    2016-10-01

    Walking and turning is a movement that places individuals with Parkinson's disease (PD) at increased risk for fall-related injury. However, turning is an essential movement in activities of daily living, making up to 45 % of the total steps taken in a given day. Hypotheses regarding how turning is controlled suggest an essential role of anticipatory eye movements to provide feedforward information for body coordination. However, little research has investigated control of turning in individuals with PD with specific consideration for eye movements. The purpose of this study was to examine eye movement behavior and body segment coordination in individuals with PD during walking turns. Three experimental groups, a group of individuals with PD, a group of healthy young adults (YAC), and a group of healthy older adults (OAC), performed walking and turning tasks under two visual conditions: free gaze and fixed gaze. Whole-body motion capture and eye tracking characterized body segment coordination and eye movement behavior during walking trials. Statistical analysis revealed significant main effects of group (PD, YAC, and OAC) and visual condition (free and fixed gaze) on timing of segment rotation and horizontal eye movement. Within group comparisons, revealed timing of eye and head movement was significantly different between the free and fixed gaze conditions for YAC (p  0.05). In addition, while intersegment timings (reflecting segment coordination) were significantly different for YAC and OAC during free gaze (p segment coordination during turning. As such, eye movements may be an important addition to training programs for those with PD, possibly promoting better coordination during turning and potentially reducing the risk of falls.

  10. THE PEAK LATENCY OF ORBITAL PRESACCADIC SPIKE POTENTIAL WITH HORIZONTAL EYE MOVEMENTS

    Institute of Scientific and Technical Information of China (English)

    单扬; MarkL.Moster; RichardA.Roemer[

    1996-01-01

    Purpose.To investigate the peak latency of the orbital presaccedic spike potential (SP) with horizontal eyemovement in normals.Methods. Orbital SP was recorded in 28 normal subjects from 8 electrodes around the eyes with Pz as the reference while performing 5°,10°,20°,30° and 40° horizontal saccedes to visual targets. SP peak latencywas measured from SP onset to SP peak on averaged data aligned on SP peak.Re,Its. Significant main effects on SP peak latency are found for saccade size (P0. 05). No significant main effect on SP peak htency is found for eye (P>0. 05). SP peak latency increases with increasing saccade size from 5° to 40°. SP peak latency is longer with saccades back to center than away from center, and with abducting saccades than with adducting saccades. SP peak latency differs at the electrode sites with an order from shorter to longer as follows; innercanth° (IC); inferior orbit (IO); outer canthus (OC); superior orbit (SO).Conclusions. The effects on the peak latency of orbital SP can be explained by the saccade dynamic property, volume conduction as weft as physiologic and anatomic factors of the eyes and orbits. The peak latency of orbital SP can be used to reflect the temporal characteristics of ocular motor units controlling saccedic eye movement.

  11. EyeGrip: Detecting Targets in a Series of Uni-directional Moving Objects Using Optokinetic Nystagmus Eye Movements

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako

    2016-01-01

    computers. In this paper, we demonstrate the rich capabilities of EyeGrip with two example applications: 1) a mind reading game, and 2) a picture selection system. Our study shows that by selecting an appropriate speed and maximum number of visible images in the screen the proposed method can be used...... the user looks at a sequence of images moving horizontally on the display while the user's eye movements are tracked by an eye tracker. We conducted an experiment that shows the performance of the proposed approach. We also investigated the influence of the speed and maximum number of visible images...

  12. Geometry and Gesture-Based Features from Saccadic Eye-Movement as a Biometric in Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Tracy [Texas A& M University, College Station; Tourassi, Georgia [ORNL; Yoon, Hong-Jun [ORNL; Alamudun, Folami T. [ORNL

    2017-07-01

    In this study, we present a novel application of sketch gesture recognition on eye-movement for biometric identification and estimating task expertise. The study was performed for the task of mammographic screening with simultaneous viewing of four coordinated breast views as typically done in clinical practice. Eye-tracking data and diagnostic decisions collected for 100 mammographic cases (25 normal, 25 benign, 50 malignant) and 10 readers (three board certified radiologists and seven radiology residents), formed the corpus for this study. Sketch gesture recognition techniques were employed to extract geometric and gesture-based features from saccadic eye-movements. Our results show that saccadic eye-movement, characterized using sketch-based features, result in more accurate models for predicting individual identity and level of expertise than more traditional eye-tracking features.

  13. Automatic removal of eye movement artifacts from the EEG using ICA and the dipole model

    Institute of Scientific and Technical Information of China (English)

    Weidong Zhou; Jean Gotman

    2009-01-01

    12 patients were analyzed.The experimental results indicate that ICA with the dipole model is very efficient at automatically subtracting the eye movement artifacts,while retaining the EEG slow waves and making their interpretation easier.

  14. Foveating dynamic scenes based on expert's eye movements to convey perceptual skills

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2011-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Scheiter, K., Nyström, M., Gerjets, P., & Eika, B. (2011, August). Foveating dynamic scenes based on expert’s eye movements to convey perceptual skills. Presentation at ECEM, Marseille, France.

  15. Foveating dynamic scenes based on expert's eye movements to convey perceptual skills

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2011-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Scheiter, K., Nyström, M., Gerjets, P., & Eika, B. (2011, August). Foveating dynamic scenes based on expert’s eye movements to convey perceptual skills. Presentation at ECEM, Marseille, France.

  16. Dynamic eye phantom for retinal oximetry measurements

    Science.gov (United States)

    Lemaillet, Paul; Ramella-Roman, Jessica C.

    2009-11-01

    Measurements of oxygen saturation and flow in the retina can yield information about eye health and the onset of eye pathologies such as diabetic retinopathy. Recently, we developed a multiaperture camera that uses the division of the retinal image into several wavelength-sensitive subimages to compute retinal oxygen saturation. The calibration of such instruments is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this purpose, we realize an in vitro model of the human eye composed of a lens, the retina vessel, and three layers: the choroid, the retinal pigmented epithelium, and the sclera. The retinal vessel is modeled with a microtube connected to a micropump and a hemoglobin reservoir in a closed circulatory system. Hemoglobin oxygenation in the vessel could be altered using a reversible fuel cell. The sclera is represented by a Spectralon slab. The optical properties of the other layers are mimicked using titanium dioxide as a scatterer, ink as an absorber, and epoxy as a supporting structure. The optical thickness of each layer of the eye phantom is matched to each respective eye layer.

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

    Directory of Open Access Journals (Sweden)

    Iliya V Ivanov

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

  18. Treatment of dysfunctionally stored experiences with the method Eye Movement Desensitization and Reprocessing – EMDR

    OpenAIRE

    Robert Cvetek

    2002-01-01

    In this paper a new therapeutic method called EMDR (Eye Movement Desensitization and Reprocessing) is described. The method was formed mainly for treatment of posttraumatic stress disorder, but there are also some reports about success with other mental disorders. The theoretical base of EMDR and especially the accelerated information processing model, the concept of memory networks and the explanations of effects of eye movements are presented. The process of EMDR is also described.

  19. Treatment of dysfunctionally stored experiences with the method Eye Movement Desensitization and Reprocessing – EMDR

    Directory of Open Access Journals (Sweden)

    Robert Cvetek

    2002-09-01

    Full Text Available In this paper a new therapeutic method called EMDR (Eye Movement Desensitization and Reprocessing is described. The method was formed mainly for treatment of posttraumatic stress disorder, but there are also some reports about success with other mental disorders. The theoretical base of EMDR and especially the accelerated information processing model, the concept of memory networks and the explanations of effects of eye movements are presented. The process of EMDR is also described.

  20. Eye Movements during Information Processing Tasks: Individual Differences and Cultural Effects

    OpenAIRE

    2007-01-01

    The eye movements of native English speakers, native Chinese speakers, and bilingual Chinese/English speakers who were either born in China (and moved to the US at an early age) or in the US were recorded during six tasks: (1) reading, (2) face processing, (3) scene perception, (4) visual search, (5) counting Chinese characters in a passage of text, and (6) visual search for Chinese characters. Across the different groups, there was a strong tendency for consistency in eye movement behavior; ...

  1. The efficacy and psychophysiological correlates of dual-attention tasks in eye movement desensitization and reprocessing (EMDR).

    Science.gov (United States)

    Schubert, Sarah J; Lee, Christopher W; Drummond, Peter D

    2011-01-01

    This study aimed to investigate the psychophysiological correlates and the effectiveness of different dual-attention tasks used during eye movement desensitization and reprocessing (EMDR). Sixty-two non-clinical participants with negative autobiographical memories received a single session of EMDR without eye movements, or EMDR that included eye movements of either varied or fixed rate of speed. Subjective units of distress and vividness of the memory were recorded at pre-treatment, post-treatment, and 1 week follow-up. EMDR-with eye movements led to greater reduction in distress than EMDR-without eye movements. Heart rate decreased significantly when eye movements began; skin conductance decreased during eye movement sets; heart rate variability and respiration rate increased significantly as eye movements continued; and orienting responses were more frequent in the eye movement than no-eye movement condition at the start of exposure. Findings indicate that the eye movement component in EMDR is beneficial, and is coupled with distinct psychophysiological changes that may aid in processing negative memories.

  2. Experience-dependent eye movements reflect hippocampus-dependent (aware) memory

    Science.gov (United States)

    Smith, Christine N.; Squire, Larry R.

    2008-01-01

    We investigated the relationship between experience-dependent eye movements, hippocampus-dependent memory, and aware memory. We measured eye movements in young adults, older adults, and memory-impaired patients with damage to the medial temporal lobe as they viewed 120 novel scenes and 120 previously viewed scenes. Participants indicated if each scene was old or new and also gave a confidence rating for the memory judgment. Young adults and older adults explored old scenes less than they explored new scenes, but the patients did not. For the young and older adults, this effect was observed only when participants were aware of the scene’s familiar or novel status. In a second experiment, young adults viewed scenes that were either new, had been viewed previously, or had been viewed previously but had been changed (i.e., an object within the scene was either added or removed). The only instructions were to pay attention to the scenes and view each scene as it appeared, and there was no expectation that memory would be tested. Directly after the first altered scene was presented, participants were asked to classify the scene as new, old, or old but changed. Participants who were aware of the manipulation preferentially viewed the changed region, but participants who were unaware did not. These findings suggest that experience-dependent eye movements reflect hippocampus-dependent (and aware) memory, even when participants have no expectation that memory is being tested; and they are consistent with the view that awareness of what is learned is a fundamental characteristic of hippocampus-dependent memory. PMID:19036976

  3. Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods.

    Science.gov (United States)

    Nickel, Allison E; Henke, Katharina; Hannula, Deborah E

    2015-01-01

    While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test); for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test). Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness.

  4. Relational Memory Is Evident in Eye Movement Behavior despite the Use of Subliminal Testing Methods.

    Directory of Open Access Journals (Sweden)

    Allison E Nickel

    Full Text Available While it is generally agreed that perception can occur without awareness, there continues to be debate about the type of representational content that is accessible when awareness is minimized or eliminated. Most investigations that have addressed this issue evaluate access to well-learned representations. Far fewer studies have evaluated whether or not associations encountered just once prior to testing might also be accessed and influence behavior. Here, eye movements were used to examine whether or not memory for studied relationships is evident following the presentation of subliminal cues. Participants assigned to experimental or control groups studied scene-face pairs and test trials evaluated implicit and explicit memory for these pairs. Each test trial began with a subliminal scene cue, followed by three visible studied faces. For experimental group participants, one face was the studied associate of the scene (implicit test; for controls none were a match. Subsequently, the display containing a match was presented to both groups, but now it was preceded by a visible scene cue (explicit test. Eye movements were recorded and recognition memory responses were made. Participants in the experimental group looked disproportionately at matching faces on implicit test trials and participants from both groups looked disproportionately at matching faces on explicit test trials, even when that face had not been successfully identified as the associate. Critically, implicit memory-based viewing effects seemed not to depend on residual awareness of subliminal scene cues, as subjective and objective measures indicated that scenes were successfully masked from view. The reported outcomes indicate that memory for studied relationships can be expressed in eye movement behavior without awareness.

  5. Rapid eye movement-sleep is reduced in patients with acute uncomplicated diverticulitis—an observational study

    Directory of Open Access Journals (Sweden)

    Chenxi Huang

    2015-08-01

    Full Text Available Introduction. Sleep disturbances are commonly found in patients in the postoperative period. Sleep disturbances may give rise to several complications including cardiopulmonary instability, transient cognitive dysfunction and prolonged convalescence. Many factors including host inflammatory responses are believed to cause postoperative sleep disturbances, as inflammatory responses can alter sleep architecture through cytokine-brain interactions. Our aim was to investigate alteration of sleep architecture during acute infection and its relationships to inflammation and clinical symptoms.Materials & Methods. In this observational study, we included patients with acute uncomplicated diverticulitis as a model to investigate the isolated effects of inflammatory responses on sleep. Eleven patients completed the study. Patients were admitted and treated with antibiotics for two nights, during which study endpoints were measured by polysomnography recordings, self-reported discomfort scores and blood samples of cytokines. One month later, the patients, who now were in complete remission, were readmitted and the endpoints were re-measured (the baseline values.Results. Total sleep time was reduced 4% and 7% the first (p = 0.006 and second (p = 0.014 nights of diverticulitis, compared to baseline, respectively. The rapid eye movement sleep was reduced 33% the first night (p = 0.016, compared to baseline. Moreover, plasma IL-6 levels were correlated to non-rapid eye movement sleep, rapid eye movement sleep and fatigue.Conclusion. Total sleep time and rapid eye movement sleep were reduced during nights with active diverticulitis and correlated with markers of inflammation.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  9. Saccadic Eye Movements Impose a Natural Bottleneck on Visual Short-Term Memory

    Science.gov (United States)

    Ohl, Sven; Rolfs, Martin

    2017-01-01

    Visual short-term memory (VSTM) is a crucial repository of information when events unfold rapidly before our eyes, yet it maintains only a fraction of the sensory information encoded by the visual system. Here, we tested the hypothesis that saccadic eye movements provide a natural bottleneck for the transition of fragile content in sensory memory…

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

    Science.gov (United States)

    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…

  11. Methodological Aspects of Cognitive Rehabilitation with Eye Movement Desensitization and Reprocessing (EMDR).

    Science.gov (United States)

    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.

  12. DISTANCE MEASURING MODELING AND ERROR ANALYSIS OF DUAL CCD VISION SYSTEM SIMULATING HUMAN EYES AND NECK

    Institute of Scientific and Technical Information of China (English)

    Wang Xuanyin; Xiao Baoping; Pan Feng

    2003-01-01

    A dual-CCD simulating human eyes and neck (DSHEN) vision system is put forward. Its structure and principle are introduced. The DSHEN vision system can perform some movements simulating human eyes and neck by means of four rotating joints, and realize precise object recognizing and distance measuring in all orientations. The mathematic model of the DSHEN vision system is built, and its movement equation is solved. The coordinate error and measure precision affected by the movement parameters are analyzed by means of intersection measuring method. So a theoretic foundation for further research on automatic object recognizing and precise target tracking is provided.

  13. Eye Movements during Art Appreciation by Students Taking a Photo Creation Course.

    Science.gov (United States)

    Ishiguro, Chiaki; Yokosawa, Kazuhiko; Okada, Takeshi

    2016-01-01

    Previous studies have focused on the differences in the art appreciation process between individuals, and indicated that novice viewers of artworks, in comparison to experts, rarely consider the creation process of the artwork or how this may relate to style. However, behavioral changes in individuals after educational interventions have not been examined. Art education researchers claim that technical knowledge and creation experiences help novice viewers to pay attention to technical features of artwork. Therefore, an artistic photo creation course was designed and conducted to help students acquire techniques and procedural knowledge of photo creation. The present study verified whether students' viewing strategies during appreciation of photographs changed after the course. Twenty-one students participated in two sessions, viewing the same 12 photographs before and after the course. Based on the analysis of recorded eye movements, the results indicated that the students' perceptual exploration became more active with photographs containing recognizable subjects (i.e., humans and objects), and their global saccades increased when they viewed classic photography, one of the categories of photography covered in the course. Interview data after the course indicated that students became aware of the technical effects in photographs. These results suggest that students' viewing strategies may change following a course, as assessed by behavioral measures of eye movements. Further examination is needed to validate this approach to educational effect measurement.

  14. Eye movements during art appreciation by students taking a photo creation course

    Directory of Open Access Journals (Sweden)

    Chiaki Ishiguro

    2016-07-01

    Full Text Available Previous studies have focused on the differences in the art appreciation process between individuals, and indicated that novice viewers of artworks, in comparison to experts, rarely consider the creation process of the artwork or how this may relate to style. However, behavioral changes in individuals after educational interventions have not been examined. Art education researchers claim that technical knowledge and creation experiences help novice viewers to pay attention to technical features of artwork. Therefore, an artistic photo creation course was designed and conducted to help students acquire techniques and procedural knowledge of photo creation. The present study verified whether students’ viewing strategies during appreciation of photographs changed after the course. Twenty-one students participated in two sessions, viewing the same 12 photographs before and after the course. Based on the analysis of recorded eye movements, the results indicated that the students’ perceptual exploration became more active with photographs containing recognizable subjects (i.e., humans and objects, and their global saccades increased when they viewed classic photography, one of the categories of photography covered in the course. Interview data after the course indicated that students became aware of the technical effects in photographs. These results suggest that students’ viewing strategies may change following a course, as assessed by behavioral measures of eye movements. Further examination is needed to validate this approach to educational effect measurement.

  15. Eye Tracking in the Cockpit: a Review of the Relationships between Eye Movements and the Aviators Cognitive State

    Science.gov (United States)

    2014-12-01

    frequency. In particular, Spady (1978) examined eye movements during simulated landing approach under instrument flight rules ( IFR ). Simulated turbulence...al. (2007) found that NNI varied across phases of simulated IFR flight, showing the least random (most clustered) distribution of fixations during...decreased for visually demanding flight segments ( IFR vs. VFR, landing vs. cruise). This general pattern has been replicated across several studies

  16. Eye-movements in a two-dimensional plane: A method for calibration and analysis using the vertical and horizontal EOG

    NARCIS (Netherlands)

    Slangen, J.L.; Woestenburg, J.C.; Verbaten, M.N.

    1984-01-01

    A method for calibration, orthogonalization and standardization of eye movements is described. The method is based on linear transformation of the horizontal and vertical EOG. With this method it is possible to measure the locus of eye fixation on a TV screen and its associated fixation time.

  17. Effects of constraint-induced therapy combined with eye patching on functional outcomes and movement kinematics in poststroke neglect.

    Science.gov (United States)

    Wu, Ching-Yi; Wang, Tien-Ni; Chen, Yu-Ting; Lin, Keh-Chung; Chen, Yi-An; Li, Hsiang-Ting; Tsai, Pei-Luen

    2013-01-01

    OBJECTIVE. We investigated the effect of constraint-induced therapy (CIT) plus eye patching (EP), CIT alone, and conventional treatment on functional performance, eye movement, and trunk-arm kinematics in stroke patients with neglect syndrome. METHOD. Twenty-four participants were recruited and randomly allocated to three intervention groups. All participants received intervention 2 hr/day, 5 days/wk, for 3 wk. Outcome measures included the Catherine Bergego Scale, eye movement, and trunk-arm kinematic analysis. RESULTS. The CIT + EP and CIT groups demonstrated larger improvements in functional performance than the control group. The CIT group showed better performance with left fixation points than the CIT+EP group and shorter reaction time than the control group. The CIT + EP group improved more in preplanned control and leftward trunk shift than the other two groups. CONCLUSION. CIT + EP and CIT were more effective interventions than conventional treatment of patients with neglect syndrome in daily functional performance.

  18. Inferences about predictable events: eye movements during reading.

    Science.gov (United States)

    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.

  19. Eye Movements: a Window on Sensory and Motor Deficits : Oogbewegingen: inzicht in sensorische en motorische aandoeningen

    NARCIS (Netherlands)

    I. Montfoort (Inger)

    2009-01-01

    markdownabstract__Abstract__ Eye movements can be used as a tool for investigating neural mechanisms of both sensory and motor deficits. Not only does the oculomotor system comprise the entire transformation from sensory input to the generation of movement, also its accessibility, its ability

  20. Identification of Information-Seeking Behaviors from Air Traffic Controllers′Eye Movements

    Institute of Scientific and Technical Information of China (English)

    Wang Yanjun; LiuYinxin; Cong Wei; Xu Xinhua; HuMinghua

    2016-01-01

    Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired from various sources.The understanding of their information seeking behaviors is still limited.We aim to identify controllers′behavior through the examination of the correlations between controllers′eye movements and air traf-fic.Sixteen air traffic controllers were invited to participate real-time simulation experiments,during which the da-ta of their eye ball movements and air traffic were recorded.Tweny-three air traffic complexity metrics and six eye movements metrics were calculated to examine their relationships.Two correlational methods,Pearson′s correla-tion and Spearman′s correlation,were tested between every eye-traffic pair of metrics.The results indicate that controllers′two kinds of information-seeking behaviors can be identified from their eye movements:Targets track-ing,and confliction recognition.The study on controllers′eye movements may contribute to the understanding of information-seeking mechanisms leading to the development of more intelligent automations in the future.

  1. Tones inferior to eye movements in the EMDR treatment of PTSD.

    Science.gov (United States)

    van den Hout, Marcel A; Rijkeboer, Marleen M; Engelhard, Iris M; Klugkist, Irene; Hornsveld, Hellen; Toffolo, Marieke J B; Cath, Danielle C

    2012-05-01

    Eye Movement Desensitization and Reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder (PTSD). During EMDR, patients make eye movements (EMs) while recalling traumatic memories, but recently therapists have replaced EMs by alternating beep tones. There are no outcome studies on the effects of tones. In an earlier analogue study, tones were inferior to EMs in the reduction of vividness of aversive memories. In a first EMDR session, 12 PTSD patients recalled trauma memories in three conditions: recall only, recall + tones, and recall + EMs. Three competing hypotheses were tested: 1) EMs are as effective as tones and better than recall only, 2) EMs are better than tones and tones are as effective as recall only, and 3) EMs are better than tones and tones are better than recall only. The order of conditions was balanced, each condition was delivered twice, and decline in memory vividness and emotionality served as outcome measures. The data strongly support hypothesis 2 and 3 over 1: EMs outperformed tones while it remained unclear if tones add to recall only. The findings add to earlier considerations and earlier analogue findings suggesting that EMs are superior to tones and that replacing the former by the latter was premature.

  2. Eye movements during saccadic and fixation tasks in patients with homonymous hemianopia.

    Science.gov (United States)

    Reinhard, Jens I; Damm, Ingelene; Ivanov, Iliya V; Trauzettel-Klosinski, Susanne

    2014-12-01

    The aim of our study was to quantify ocular motor performance in patients with homonymous hemianopia and in healthy controls during saccadic and fixation tasks and to detect potential spontaneous adaptive mechanisms in the hemianopic patients. Eye movements were recorded in 33 hemianopic patients (15 right, 18 left; disease duration, 0.2-29 years) and 14 healthy subjects by scanning laser ophthalmoscope allowing determination of the absolute fovea position relative to the stimulus without calibration. Landing accuracy of saccades was determined for 5° saccades, indicated by the number of dysmetric saccades (DS), and fixation stability (FS) after landing. In addition, during continuous fixation of a central cross, FS, and distribution of fixational eye movements (FEMs) were measured. Size of macular sparing was determined using custom microperimetry software (stimulus grid, 0.5°). Compared with controls, landing accuracy was decreased in hemianopic patients, indicated by significantly more DS (hypometric and hypermetric) to the blind side compared with the seeing side. The number of DS was greater in patients with macular sparing of FEM during continuous fixation was asymmetrically shifted to the blind side, especially in cases of macular sparing of FEMs during continuous fixation indicate an advantageous adaptive mechanism to shift the visual field border towards the hemianopic side.

  3. Evidence of an eye movement-based memory effect in congenital prosopagnosia.

    Science.gov (United States)

    Bate, Sarah; Haslam, Catherine; Tree, Jeremy J; Hodgson, Timothy L

    2008-01-01

    While extensive work has examined the role of covert recognition in acquired prosopagnosia, little attention has been directed to this process in the congenital form of the disorder. Indeed, evidence of covert recognition has only been demonstrated in one congenital case in which autonomic measures provided evidence of recognition (Jones and Tranel, 2001), whereas two investigations using behavioural indicators failed to demonstrate the effect (de Haan and Campbell, 1991; Bentin et al., 1999). In this paper, we use a behavioural indicator, an "eye movement-based memory effect" (Althoff and Cohen, 1999), to provide evidence of covert recognition in congenital prosopagnosia. In an initial experiment, we examined viewing strategies elicited to famous and novel faces in control participants, and found fewer fixations and reduced regional sampling for famous compared to novel faces. In a second experiment, we examined the same processes in a patient with congenital prosopagnosia (AA), and found some evidence of an eye movement-based memory effect regardless of his recognition accuracy. Finally, we examined whether a difference in scanning strategy was evident for those famous faces AA failed to explicitly recognise, and again found evidence of reduced sampling for famous faces. We use these findings to (a) provide evidence of intact structural representations in a case of congenital prosopagnosia, and (b) to suggest that covert recognition can be demonstrated using behavioural indicators in this disorder.

  4. Effects of belief and logic on syllogistic reasoning: Eye-movement evidence for selective processing models.

    Science.gov (United States)

    Ball, Linden J; Phillips, Peter; Wade, Caroline N; Quayle, Jeremy D

    2006-01-01

    Studies of syllogistic reasoning have demonstrated a nonlogical tendency for people to endorse more believable conclusions than unbelievable ones. This belief bias effect is more dominant on invalid syllogisms than valid ones, giving rise to a logic by belief interaction. We report an experiment in which participants' eye movements were recorded in order to provide insights into the nature and time course of the reasoning processes associated with manipulations of conclusion validity and believability. Our main dependent measure was people's inspection times for syllogistic premises, and we tested predictions deriving from three contemporary mental-models accounts of the logic by belief interaction. Results supported recent "selective processing" theories of belief bias (e.g., Evans, 2000; Klauer, Musch, & Naumer, 2000), which assume that the believability of a conclusion biases model construction processes, rather than biasing the search for falsifying models (e.g., Oakhill & Johnson-Laird, 1985) or a response stage of reasoning arising from subjective uncertainty (e.g., Quayle & Ball, 2000). We conclude by suggesting that the eye-movement analyses in reasoning research may provide a useful adjunct to other process-tracing techniques such as verbal protocol analysis.

  5. Picture perception in Chinese dyslexic children: an eye-movement study

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-hong; JING Jin; ZOU Xiao-bing; HUANG Xu; JIN Yu; WANG Qing-xiong; CHEN Xue-bin; YANG Bin-rang; YANG Si-yuan

    2009-01-01

    Background Currently, whether or not there is visuospatial impairments in Chinese dyslexic children is still a matter of discussion. The relatively recent application of an eye-tracking paradigm may offer an opportunity to address this issue. In China, in comparison with reading studies, there have not been nearly as many eye movement studies dealing with nonreading tasks such as picture identification and whether Chinese children with dyslexia have a picture processing deficit is not clear. The purposes of the present study were to determine whether or not there is visuospatial impairments in Chinese dyslexic children. Moreover, we attempted to discuss whether or not the abnormal eye movement pattern that dyslexic subjects show during reading of text appropriate for their age is a consequence of their linguistic difficulties.Methods An eye-link Ⅱ High-Speed Eye Tracker was used to track the series of eye-movement of 19 Chinese dyslexic children and 19 Chinese normal children. All of the subjects were presented with three pictures for this eye-tracking task and 6 relative eye-movement parameters, first fixation duration, average fixation duration, average saccade amplitude, mean saccade distance, fixation frequency and saccade frequency were recorded for analysis.Results Analyzing the relative parameter among three pictures, except for the fixation frequency and the saccade frequency, other eye-movement parameters were significantly different among the three pictures (P 0.05).Conclusions The characteristics of the pictures can significantly influence the visuospatial cognitive processing capability of the Chinese children. There is a detectable disability for the Chinese dyslexic children in the visuospatial cognitive processing: their saccade amplitude and mean saccade distance are shorter, which may be interpreted as specific for their reading disability.

  6. Test of the neurolinguistic programming hypothesis that eye-movements relate to processing imagery.

    Science.gov (United States)

    Wertheim, E H; Habib, C; Cumming, G

    1986-04-01

    Bandler and Grinder's hypothesis that eye-movements reflect sensory processing was examined. 28 volunteers first memorized and then recalled visual, auditory, and kinesthetic stimuli. Changes in eye-positions during recall were videotaped and categorized by two raters into positions hypothesized by Bandler and Grinder's model to represent visual, auditory, and kinesthetic recall. Planned contrast analyses suggested that visual stimulus items, when recalled, elicited significantly more upward eye-positions and stares than auditory and kinesthetic items. Auditory and kinesthetic items, however, did not elicit more changes in eye-position hypothesized by the model to represent auditory and kinesthetic recall, respectively.

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

    Science.gov (United States)

    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

  8. Eyes Do Not Have it: A Collinear Salient Line Interferes with Visual Search Responses but Not Eye Movements

    Directory of Open Access Journals (Sweden)

    Li Jingling

    2011-05-01

    Full Text Available Our previous study found that a task-irrelevant salient line impaired visual search when the salient line was composite of collinear bars (Jingling, 2010. In this study, we further investigated whether this inhibition can be observed in eye movements. The search display was a lattice of 21 by 27 bars. The task was to discriminate the orientation of a target, which was presented on one of seven bars in the central of search display. One of the columns of the bars was vertical, thus bars on this line were collinear to each other. The other bars were horizontal, making the collinear line salient. The target was on the bars at salient line by chance. Eight participants were recruited, and eye movements were recorded by EyeLink 1,000 with 250 Hz sampling rate. Results of hand response times replicated our previous findings: Responses were slower for targets on the bars at the salient line than that in the background. However, saccadic duration was not statistically different for these two types of targets. Our data showed that a collinear salient line interferes with key press but not eye movements, suggesting that the inhibitory effect emerged later than sensory information process.

  9. Infant Visual Assessment: Using Eye Tracking to Measure Visual Acuity

    Directory of Open Access Journals (Sweden)

    Eliza Burton

    2012-05-01

    Full Text Available A technique commonly used to assess infants' visual acuity is forced-choice preferential looking, which relies on the propensity of infants to look at patterned stimuli over uniform grey. Existing tests use trained examiners to judge where an infant fixates; however, eye trackers offer the opportunity to measure eye movements quickly and automatically. In the present study infants' visual acuity was measured using a remote Tobii eye tracker (Tobii T120. Thirteen infants aged 4–8 months were seated before a screen and presented with a preferential looking task. On each trial a black and white chequerboard of variable spatial frequency was displayed on half of the screen, while uniform grey was displayed elsewhere. Eye tracking data were used to determine whether the infant fixated the chequerboard and to update the spatial frequency on subsequent trials according to a weighted up-down staircase targeting the 75% threshold. This initial study showed data in line with age norms are consistent across two testing sessions for some infants. Others yielded poor data or inconsistent performance. Future modifications will aim to make the test more engaging and to optimise its power and speed. These will provide a basis for a full assessment of the test's accuracy and reliability.

  10. The independence of eye movements in a stomatopod crustacean is task dependent.

    Science.gov (United States)

    Daly, Ilse M; How, Martin J; Partridge, Julian C; Roberts, Nicholas W

    2017-04-01

    Stomatopods have an extraordinary visual system, incorporating independent movement of their eyes in all three degrees of rotational freedom. In this work, we demonstrate that in the peacock mantis shrimp, Odontodactylus scyllarus, the level of ocular independence is task dependent. During gaze stabilization in the context of optokinesis, there is weak but significant correlation between the left and right eyes in the yaw degree of rotational freedom, but not in pitch and torsion. When one eye is completely occluded, the uncovered eye does not drive the covered eye during gaze stabilization. However, occluding one eye does significantly affect the uncovered eye, lowering its gaze stabilization performance. There is a lateral asymmetry, with the magnitude of the effect depending on the eye (left or right) combined with the direction of motion of the visual field. In contrast, during a startle saccade, the uncovered eye does drive a covered eye. Such disparate levels of independence between the two eyes suggest that responses to individual visual tasks are likely to follow different neural pathways. © 2017. Published by The Company of Biologists Ltd.

  11. Eye-movement study during visual search in Chinese children with developmental dyslexia

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-hong; JING Jin; YANG De-sheng; WANG Hui; WANG Qing-xiong; SONG Shan-shan; FAN Fang

    2013-01-01

    Background Developmental dyslexia (DD) is a disorder in which children with normal intelligence and sensory abilities show learning deficits in reading.Abnormal eye movements have been found in DD.However,eye-movement abnormalities during visual search among Chinese children with DD remain unknown.We aimed to identify the eyemovement characteristics and search efficiency of Chinese children with DD during visual search for targets of different conceptual categories,under same-category conditions.Methods We compared 32 Chinese dyslexic children and 39 non-dyslexic children in visual search tasks,which were assessed using EyeLink Ⅱ High-Speed Eye Tracker (SR Research Ltd.,Canada).Letters,single Chinese characters,digits,Chinese phrases,figures and facial expressions were used as stimuli.Targets were similar to distractors in meaning,phonology and/or shape.Results A main effect of task on visual search scores and all eye-movement parameters were found.Search scores,average saccade amplitude and saccade distance were significantly smaller in the DD group than in the controls.An interaction between group and task was found for pupil diameter.Conclusions Unlike normal readers,children with DD had a reduction in the visual attention span and search accuracy.Besides,children with DD could not increase their mental workload with increase in task difficulty.The conceptual category of the stimulus materials significantly impacts search speed,accuracy and eye-movement parameters.

  12. Rapid Nonconjugate Adaptation of Vertical Voluntary Pursuit Eye Movements

    Science.gov (United States)

    1991-01-01

    applied to the post-adaptation data from the left eye magnification condition: YRpost(Transformed) = (2 * YRpre) - YRPost (6) For example, if the pie ...nonconjugate adaptation with spectacle- mounted plano -cylindrical lenses, Lemij (1990) demonstrated that nonconjugate pursuit adaptation was

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

    Science.gov (United States)

    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).

  14. The role of eye movements in depth from motion parallax during infancy.

    Science.gov (United States)

    Nawrot, Elizabeth; Nawrot, Mark

    2013-12-18

    Motion parallax is a motion-based, monocular depth cue that uses an object's relative motion and velocity as a cue to relative depth. In adults, and in monkeys, a smooth pursuit eye movement signal is used to disambiguate the depth-sign provided by these relative motion cues. The current study investigates infants' perception of depth from motion parallax and the development of two oculomotor functions, smooth pursuit and the ocular following response (OFR) eye movements. Infants 8 to 20 weeks of age were presented with three tasks in a single session: depth from motion parallax, smooth pursuit tracking, and OFR to translation. The development of smooth pursuit was significantly related to age, as was sensitivity to motion parallax. OFR eye movements also corresponded to both age and smooth pursuit gain, with groups of infants demonstrating asymmetric function in both types of eye movements. These results suggest that the development of the eye movement system may play a crucial role in the sensitivity to depth from motion parallax in infancy. Moreover, describing the development of these oculomotor functions in relation to depth perception may aid in the understanding of certain visual dysfunctions.

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

    Science.gov (United States)

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

    2016-01-01

    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. 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. 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. 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.

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Individual Differences in Eye-Movements During Reading: Working Memory and Speed-of-Processing Effects.

    Science.gov (United States)

    Traxler, Matthew J; Long, Debra L; Tooley, Kristen M; Johns, Clinton L; Zirnstein, Megan; Jonathan, Eunike

    Theories of eye-movement control in reading should ultimately describe how differences in knowledge and cognitive abilities affect reading and comprehension. Current mathematical models of eye-movement control do not yet incorporate individual differences as a source of variation in reading, although developmental and group-difference effects have been studied. These models nonetheless provide an excellent foundation for describing and explaining how and why patterns of eye-movements differ across readers (e.g., Rayner, Chace, & Ashby, 2006). Our focus in this article is on two aspects of individual variation: global processing speed (e.g., Salthouse, 1996) and working-memory capacity (e.g., Just & Carpenter, 1992). Using Hierarchical Linear Modeling (HLM) (Raudenbush & Bryk, 2001), we tested the extent to which overall reading speed and working-memory capacity moderate the degree to which syntactic and semantic information affect fixation times. Previous published data (Traxler et al., 2005) showed that working memory capacity and syntactic complexity interacted to determine fixation times in an eye-movement monitoring experiment. In a new set of models based on this same data set, we found that working-memory capacity interacted with sentence-characteristic variables only when processing speed was not included in the model. We interpret these findings with respect to current accounts of sentence processing and suggest how they might be incorporated into eye-movement control models.

  18. Fractal measures of female caribou movements

    Directory of Open Access Journals (Sweden)

    Steven H. Ferguson

    2011-03-01

    Full Text Available Understanding caribou movement during short-term searches for specific habitats, potential mates, and refugia against predators can help resolve ecological questions on how individual caribou perceive their environment. We used measures of fractal dimension and standardized pathlength to compare the movement pathways of female caribou. Satellite telemetry locations were collected over a 2-year study, March 1994 to mid-May 1996, for a caribou population in central Saskatchewan living in the southern boreal forest. Female caribou displayed more random searching behaviour during winter and more regular dispersal movements during early winter/spring and autumn periods. Females with a calf showed no difference in movement pattern (fractal dimension relative to females without a calf but their standardized path length was shorter. We discuss the advantages of using fractal dimension as a measure of the tortuosity of movement pathways and how changes in fractal dimension over a range of scales can define domains of consistent ecological processes.

  19. On-line analysis of eye movements using a digital computer.

    Science.gov (United States)

    Baloh, R W; Langhofer, L; Honrubia, V; Yee, R D

    1980-06-01

    We describe a microcomputer system for on-line analysis of eye movement recordings. Quantitative data from the patient and statistical comparison with normative data is available within seconds of test completion. Three types of eye movements are analyzed--voluntary saccades, smooth pursuit, and nystagmus. The first two are induced by a computer-controlled laser dot projected onto a screen and the third by a computer-controlled optokinetic drum, caloric infusion, and rotatory chair. The computer algorithm differentiates the eye position signal to yield an instantaneous eye velocity record. Saccades are identified based on their characteristic velocity profile. For pursuit and nystagmus. The first two are induced by a computer-controlled laser dot projected onto a screen and the third by a computer-controlled optokinetic drum, caloric infusion, and rotatory chair. The computer algorithm differentiates the eye position signal to yield an instaneous eye velocity record. Saccades are identified based on their characteristic velocity profile. For pursuit and nystagmus, the velocity record is modified by linearly interpolating across segments in which saccades occurred. The gain (output eye velocity/input eye velocity) is calculated after Fourier analysis of the data.

  20. The pupil is faster than the corneal reflection (CR): are video based pupil-CR eye trackers suitable for studying detailed dynamics of eye movements?

    NARCIS (Netherlands)

    Hooge, I.T.C.; Holmqvist, K.; Nyström, Marcus

    2016-01-01

    Most modern video eye trackers use the p-CR (pupil minus CR) technique to deal with small relative movements between the eye tracker camera and the eye. We question whether the p-CR technique is appropriate to investigate saccade dynamics. In two experiments we investigated the dynamics of pupil, CR

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

    Science.gov (United States)

    Kearns, Michelle; Engelhard, Iris M

    2015-01-01

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

  2. Degrading traumatic memories with eye movements: a pilot functional MRI study in PTSD

    Science.gov (United States)

    Thomaes, Kathleen; Engelhard, Iris M.; Sijbrandij, Marit; Cath, Danielle C.; Van den Heuvel, Odile A.

    2016-01-01

    Background Eye movement desensitization and reprocessing (EMDR) is an effective treatment for posttraumatic stress disorder (PTSD). During EMDR, the patient recalls traumatic memories while making eye movements (EMs). Making EMs during recall is associated with decreased vividness and emotionality of traumatic memories, but the underlying mechanism has been unclear. Recent studies support a “working-memory” (WM) theory, which states that the two tasks (recall and EMs) compete for limited capacity of WM resources. However, prior research has mainly relied on self-report measures. Methods Using functional magnetic resonance imaging, we tested whether “recall with EMs,” relative to a “recall-only” control condition, was associated with reduced activity of primary visual and emotional processing brain regions, associated with vividness and emotionality respectively, and increased activity of the dorsolateral prefrontal cortex (DLPFC), associated with working memory. We used a randomized, controlled, crossover experimental design in eight adult patients with a primary diagnosis of PTSD. A script-driven imagery (SDI) procedure was used to measure responsiveness to an audio-script depicting the participant's traumatic memory before and after conditions. Results SDI activated mainly emotional processing-related brain regions (anterior insula, rostral anterior cingulate cortex (ACC), and dorsomedial prefrontal cortex), WM-related (DLPFC), and visual (association) brain regions before both conditions. Although predicted pre- to post-test decrease in amygdala activation after “recall with EMs” was not significant, SDI activated less right amygdala and rostral ACC activity after “recall with EMs” compared to post-“recall-only.” Furthermore, functional connectivity from the right amygdala to the rostral ACC was decreased after “recall with EMs” compared with after “recall-only.” Conclusions These preliminary results in a small sample suggest that

  3. Subliminal gait initiation deficits in rapid eye movement sleep behavior disorder: A harbinger of freezing of gait?

    Science.gov (United States)

    Alibiglou, Laila; Videnovic, Aleksandar; Planetta, Peggy J; Vaillancourt, David E; MacKinnon, Colum D

    2016-11-01

    Muscle activity during rapid eye movement sleep is markedly increased in people with rapid eye movement sleep behavior disorder and people with Parkinson's disease (PD) who have freezing of gait. This study examined whether individuals with rapid eye movement sleep behavior disorder who do not have a diagnosis of PD show abnormalities in gait initiation that resemble the impairments observed in PD and whether there is a relationship between these deficits and the level of rapid eye movement sleep without atonia. Gait initiation and polysomnography studies were conducted in 4 groups of 10 participants: rapid eye movement sleep behavior disorder, PD with and without freezing of gait, and controls. Significant reductions were seen in the posterior shift of the center of pressure during the propulsive phase of gait initiation in the groups with rapid eye movement sleep behavior disorder and PD with freezing of gait when compared with controls and PD nonfreezers. These reductions negatively correlated with the amount of rapid eye movement sleep without atonia. The duration of the initial dorsiflexor muscle burst during gait initiation was significantly reduced in both PD groups and the rapid eye movement sleep behavior disorder cohort. These results provide evidence that people with rapid eye movement sleep behavior disorder, prior to a diagnosis of a degenerative neurologic disorder, show alterations in the coupling of posture and gait similar to those seen in PD. The correlation between increased rapid eye movement sleep without atonia and deficits in forward propulsion during the push-off phase of gait initiation suggests that abnormities in the regulation of muscle tone during rapid eye movement sleep may be related to the pathogenesis of freezing of gait. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  4. Anticipatory Eye Movements While Watching Continuous Action Across Shots in Video Sequences: A Developmental Study.

    Science.gov (United States)

    Kirkorian, Heather L; Anderson, Daniel R

    2017-07-01

    Eye movements were recorded as 12-month-olds (n = 15), 4-year-olds (n = 17), and adults (n = 19) watched a 15-min video with sequences of shots conveying continuous motion. The central question was whether, and at what age, viewers anticipate the reappearance of objects following cuts to new shots. Adults were more likely than younger viewers to make anticipatory eye movements. Four-year-olds responded to transitions more slowly and tended to fixate the center of the screen. Infants' eye movement patterns reflected a tendency to react rather than anticipate. Findings are consistent with the hypothesis that adults integrate content across shots and understand how space is represented in edited video. Results are interpreted with respect to a developing understanding of film editing due to experience and cognitive maturation. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  5. Advanced statistical methods for eye movement analysis and modeling: a gentle introduction

    CERN Document Server

    Boccignone, Giuseppe

    2015-01-01

    In this Chapter we show that by considering eye movements, and in particular, the resulting sequence of gaze shifts, a stochastic process, a wide variety of tools become available for analyses and modelling beyond conventional statistical methods. Such tools encompass random walk analyses and more complex techniques borrowed from the pattern recognition and machine learning fields. After a brief, though critical, probabilistic tour of current computational models of eye movements and visual attention, we lay down the basis for gaze shift pattern analysis. To this end, the concepts of Markov Processes, the Wiener process and related random walks within the Gaussian framework of the Central Limit Theorem will be introduced. Then, we will deliberately violate fundamental assumptions of the Central Limit Theorem to elicit a larger perspective, rooted in statistical physics, for analysing and modelling eye movements in terms of anomalous, non-Gaussian, random walks and modern foraging theory. Eventually, by resort...

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

    Science.gov (United States)

    Kukona, Anuenue; Tabor, Whitney

    2011-08-01

    The Visual World Paradigm (VWP) 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 VWP, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the VWP.

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

    Science.gov (United States)

    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

  8. Adaptive optics scanning laser ophthalmoscope using liquid crystal on silicon spatial light modulator: Performance study with involuntary eye movement

    Science.gov (United States)

    Huang, Hongxin; Toyoda, Haruyoshi; Inoue, Takashi

    2017-09-01

    The performance of an adaptive optics scanning laser ophthalmoscope (AO-SLO) using a liquid crystal on silicon spatial light modulator and Shack-Hartmann wavefront sensor was investigated. The system achieved high-resolution and high-contrast images of human retinas by dynamic compensation for the aberrations in the eyes. Retinal structures such as photoreceptor cells, blood vessels, and nerve fiber bundles, as well as blood flow, could be observed in vivo. We also investigated involuntary eye movements and ascertained microsaccades and drifts using both the retinal images and the aberrations recorded simultaneously. Furthermore, we measured the interframe displacement of retinal images and found that during eye drift, the displacement has a linear relationship with the residual low-order aberration. The estimated duration and cumulative displacement of the drift were within the ranges estimated by a video tracking technique. The AO-SLO would not only be used for the early detection of eye diseases, but would also offer a new approach for involuntary eye movement research.

  9. Saccadic and Postsaccadic Disconjugacy in Zebrafish Larvae Suggests Independent Eye Movement Control

    Science.gov (United States)

    Chen, Chien-Cheng; Bockisch, Christopher J.; Straumann, Dominik; Huang, Melody Ying-Yu

    2016-01-01

    Spontaneous eye movements of zebrafish larvae in the dark consist of centrifugal saccades that move the eyes from a central to an eccentric position and postsaccadic centripetal drifts. In a previous study, we showed that the fitted single-exponential time constants of the postsaccadic drifts are longer in the temporal-to-nasal (T->N) direction than in the nasal-to-temporal (N->T) direction. In the present study, we further report that saccadic peak velocities are higher and saccadic amplitudes are larger in the N->T direction than in the T->N direction. We investigated the underlying mechanism of this ocular disconjugacy in the dark with a top-down approach. A mathematic ocular motor model, including an eye plant, a set of burst neurons and a velocity-to-position neural integrator (VPNI), was built to simulate the typical larval eye movements in the dark. The modeling parameters, such as VPNI time constants, neural impulse signals generated by the burst neurons and time constants of the eye plant, were iteratively adjusted to fit the average saccadic eye movement. These simulations suggest that four pools of burst neurons and four pools of VPNIs are needed to explain the disconjugate eye movements in our results. A premotor mechanism controls the synchronous timing of binocular saccades, but the pools of burst and integrator neurons in zebrafish larvae seem to be different (and maybe separate) for both eyes and horizontal directions, which leads to the observed ocular disconjugacies during saccades and postsaccadic drifts in the dark. PMID:27761109

  10. Classification of visual and linguistic tasks using eye-movement features.

    Science.gov (United States)

    Coco, Moreno I; Keller, Frank

    2014-03-07

    The role of the task has received special attention in visual-cognition research because it can provide causal explanations of goal-directed eye-movement responses. The dependency between visual attention and task suggests that eye movements can be used to classify the task being performed. A recent study by Greene, Liu, and Wolfe (2012), however, fails to achieve accurate classification of visual tasks based on eye-movement features. In the present study, we hypothesize that tasks can be successfully classified when they differ with respect to the involvement of other cognitive domains, such as language processing. We extract the eye-movement features used by Greene et al. as well as additional features from the data of three different tasks: visual search, object naming, and scene description. First, we demonstrated that eye-movement responses make it possible to characterize the goals of these tasks. Then, we trained three different types of classifiers and predicted the task participants performed with an accuracy well above chance (a maximum of 88% for visual search). An analysis of the relative importance of features for classification accuracy reveals that just one feature, i.e., initiation time, is sufficient for above-chance performance (a maximum of 79% accuracy in object naming). Crucially, this feature is independent of task duration, which differs systematically across the three tasks we investigated. Overall, the best task classification performance was obtained with a set of seven features that included both spatial information (e.g., entropy of attention allocation) and temporal components (e.g., total fixation on objects) of the eye-movement record. This result confirms the task-dependent allocation of visual attention and extends previous work by showing that task classification is possible when tasks differ in the cognitive processes involved (purely visual tasks such as search vs. communicative tasks such as scene description).

  11. Eye movements and hazard perception in police pursuit and emergency response driving.

    Science.gov (United States)

    Crundall, David; Chapman, Peter; Phelps, Nicola; Underwood, Geoffrey

    2003-09-01

    How do police cope with the visual demands placed on them during pursuit driving? This study compared the hazard ratings, eye movements, and physiological responses of police drivers with novice and with age-matched control drivers while viewing video clips of driving taken from police vehicles. The clips included pursuits, emergency responses, and control drives. Although police drivers did not report more hazards than the other participants reported, they had an increased frequency of electrodermal responses while viewing dangerous clips and a greater visual sampling rate and spread of search. However, despite an overall police advantage in oculomotor and physiological measures, all drivers had a reduced spread of search in nighttime pursuits because of the focusing of overt attention.

  12. Role descriptions induce gender mismatch effects in eye movements during reading

    Directory of Open Access Journals (Sweden)

    Chiara eReali

    2015-11-01

    Full Text Available The present eye-tracking study investigates the effect of gender typicality on the resolution of anaphoric personal pronouns in English. Participants read descriptions of a person performing a typically male, typically female or gender-neutral occupational activity. The description was followed by an anaphoric reference (he or she which revealed the referent's gender. The first experiment presented roles which were highly typical for men (e.g., blacksmith or for women (e.g., beautician, the second experiment presented role descriptions with a moderate degree of gender typicality (e.g., psychologist, lawyer. Results revealed a gender mismatch effect in early and late measures in the first experiment and in an early measure in the second experiment. Moreover, eye-movement data for highly typical roles correlated with explicit typicality ratings. The results are discussed from a cross-linguistic perspective, comparing natural gender languages and grammatical gender languages. An interpretation of the cognitive representation of typicality beliefs is proposed.

  13. A wearable device for measuring eye dynamics in real-world conditions.

    Science.gov (United States)

    Knopp, Simon; Bones, Philip; Weddell, Stephen; Innes, Carrie; Jones, Richard

    2013-01-01

    Drowsiness and lapses of responsiveness have the potential to cause fatalities in many occupations. One subsystem of a prototype device which aims to detect these lapses as they occur is described. A head-mounted camera measures several features of the eye that are known to correlate with drowsiness. The system was tested with eight combinations of eye colour, ambient lighting, and eye glasses to simulate typical real-world input conditions. A task was completed for each set of conditions to simulate a range of eye movement-saccades, tracking, and eye closure. Our image processing software correctly classified 99.3% of video frames as open/closed/partly closed, and the error rate was not affected by the combinations of input conditions. Most errors occurred during eyelid movement. The accuracy of the pupil localisation was also not influenced by input conditions, with the possible exception of one subject's glasses.

  14. Hidden Markov model analysis reveals the advantage of analytic eye movement patterns in face recognition across cultures.

    Science.gov (United States)

    Chuk, Tim; Crookes, Kate; Hayward, William G; Chan, Antoni B; Hsiao, Janet H

    2017-12-01

    It remains controversial whether culture modulates eye movement behavior in face recognition. Inconsistent results have been reported regarding whether cultural differences in eye movement patterns exist, whether these differences affect recognition performance, and whether participants use similar eye movement patterns when viewing faces from different ethnicities. These inconsistencies may be due to substantial individual differences in eye movement patterns within a cultural group. Here we addressed this issue by conducting individual-level eye movement data analysis using hidden Markov models (HMMs). Each individual's eye movements were modeled with an HMM. We clustered the individual HMMs according to their similarities and discovered three common patterns in both Asian and Caucasian participants: holistic (looking mostly at the face center), left-eye-biased analytic (looking mostly at the two individual eyes in addition to the face center with a slight bias to the left eye), and right-eye-based analytic (looking mostly at the right eye in addition to the face center). The frequency of participants adopting the three patterns did not differ significantly between Asians and Caucasians, suggesting little modulation from culture. Significantly more participants (75%) showed similar eye movement patterns when viewing own- and other-race faces than different patterns. Most importantly, participants with left-eye-biased analytic patterns performed significantly better than those using either holistic or right-eye-biased analytic patterns. These results suggest that active retrieval of facial feature information through an analytic eye movement pattern may be optimal for face recognition regardless of culture. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Development of Instrument Control System Using Biosignals Created by the Change of Eyes Movement Sequence

    Institute of Scientific and Technical Information of China (English)

    XIAO Yun-xiang(肖云翔); LI Gang(李刚); NOGATA Fumio

    2003-01-01

    A new biosignal control system that offers the disables the opportunities to control electric appliances is proposed. The four types of signals created by the eyes movements in four directions ( up, down, left, and right) ,which are taken as four basic signals, are detected at the forehead. Permutation of 2 signals out of them creates 16 different signals. Permutation of 3 signals out of them creates 64 signals. They all amounts to 84 control signals. They are thought to be applicable for the operation of some instruments. Furthermore, the dynamic biosignals created by the slow eyes movement is speculated to be applicable for the more convenient control of them.

  16. Tectal codification of eye movements in goldfish studied by electrical microstimulation. f.

    Science.gov (United States)

    Salas, C; Herrero, L; Rodriguez, F; Torres, B

    1997-05-01

    This work compares the tectal codification of eye movements in goldfish with those reported for other vertebrate groups. Focal electrical stimulation was applied in various tectal zones and the characteristics of evoked eye movements were examined as a function of (i) the position of the stimulation over the tectal surface, (ii) the initial position of the eyes and (iii) the parameters (pulse rate, current strength, duration) of the stimulus. In a large medial zone, stimulation within the intermediate and deep layers of the tectum evoked contraversive saccades of both eyes, whose direction and amplitude were roughly congruent with the retinotopic representation of the visual world within overlying layers. These saccades were minimally influenced by the initial position of the eye in the orbit. The topographical arrangement of evoked saccades and body movements suggests that this tectal zone triggers orienting responses in a similar way to those described in other vertebrates. Stimulations applied within the caudal tectum also evoked contraversive saccades, but in disagreement with the overlying retinotopic map--the vertical component was absent. Taken together with electrically evoked body movements reported in free-swimming fish, these saccades could reveal that this zone is involved in escape responses. When stimulations were applied within the anteromedial zone of the tectum, contraversive movements of both eyes appeared much more dependent on initial eye position. Saccades elicited from this area displayed characteristics of "goal-directed saccades" which were similar to those described in the cat. The generation of goal-directed movements from the anteromedial zone suggests that this portion of the goldfish optic tectum has a different intrinsic organization or is connected with the brainstem saccade generator in a different fashion than the medial zone. Finally, stimulation of the extreme anteromedial zone evoked convergent eye movements. These movements and

  17. Normal Speed and Accuracy of Saccade and Vergence Eye Movements in Dyslexic Reader Children

    Directory of Open Access Journals (Sweden)

    Maria Pia Bucci

    2009-01-01

    Full Text Available Objective. Latency of eye movements depends on cortical structures while speed of execution and accuracy depends mostly on subcortical brainstem structures. Prior studies reported in dyslexic reader children abnormalities of latencies of saccades (isolated and combined with vergence; such abnormalities were attributed to deficits of fixation control and of visual attention. In this study we examine speed and accuracy characteristics of horizontal eye movements in natural space (saccades, vergence and combined movements in dyslexic reader children. Methods. Two paradigms are tested: gap paradigm (fixation offset 200 ms prior to target onset, producing shorter latencies, in both non-dyslexic reader and dyslexic reader children and simultaneous paradigm. Seventeen dyslexic reader children (mean age: 12±0.08 years and thirteen non-dyslexic reader children (mean age: 12±1 years were tested. Horizontal eye movements from both eyes were recorded simultaneously by a photoelectric device (Oculometer, Dr. Bouis. Results. For all movements tested (saccades, vergence, isolated or combined and for both paradigms, the mean velocity and accuracy were similar in dyslexic readers and non-dyslexic readers; no significant difference was found. Conclusion. This negative but important result, suggests no dysfunction of brainstem ocular motor circuits in dyslexic readers. It contrasts results on latencies related to visual attention dysfunction at cortical level.

  18. Eye movement analysis of reading from computer displays, eReaders and printed books.

    Science.gov (United States)

    Zambarbieri, Daniela; Carniglia, Elena

    2012-09-01

    To compare eye movements during silent reading of three eBooks and a printed book. The three different eReading tools were a desktop PC, iPad tablet and Kindle eReader. Video-oculographic technology was used for recording eye movements. In the case of reading from the computer display the recordings were made by a video camera placed below the computer screen, whereas for reading from the iPad tablet, eReader and printed book the recording system was worn by the subject and had two cameras: one for recording the movement of the eyes and the other for recording the scene in front of the subject. Data analysis provided quantitative information in terms of number of fixations, their duration, and the direction of the movement, the latter to distinguish between fixations and regressions. Mean fixation duration was different only in reading from the computer display, and was similar for the Tablet, eReader and printed book. The percentage of regressions with respect to the total amount of fixations was comparable for eReading tools and the printed book. The analysis of eye movements during reading an eBook from different eReading tools suggests that subjects' reading behaviour is similar to reading from a printed book. © 2012 The College of Optometrists.

  19. Magnetic eye tracking in mice.

    Science.gov (United States)

    Payne, Hannah L; Raymond, Jennifer L

    2017-09-05

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

  20. Horizontal eye position affects measured vertical VOR gain on the video Head Impulse Test

    Directory of Open Access Journals (Sweden)

    Leigh A. McGarvie

    2015-03-01

    Full Text Available Background/Hypothesis. With the video Head Impulse Test (vHIT, the vertical VOR gain is defined as (vertical eye velocity/vertical head velocity, but compensatory eye movements to vertical canal stimulation usually have a torsional component. To minimize the contribution of torsion to the eye movement measurement, the horizontal gaze direction should be directed 40º from straight ahead so it is in the plane of the stimulated canal plane pair. Hypothesis: as gaze is systematically moved horizontally away from canal plane alignment, the measured vertical VOR gain should decrease.Study Design. 10 healthy subjects, with vHIT measuring vertical eye movement to head impulses in the plane of the left anterior-right posterior (LARP canal plane, with gaze at one of 5 horizontal gaze positions (40º (aligned with the LARP plane, 20º, 0º, -20º, -40º.Methods. Every head impulse was in the LARP plane. The compensatory eye movement was measured by the vHIT prototype system. The one operator delivered every impulse. Results. The canal stimulus remained identical across trials, but the measured vertical VOR gain decreased as horizontal gaze angle was shifted away from alignment with the LARP canal plane.Conclusion. In measuring vertical VOR gain with vHIT the horizontal gaze angle should be aligned with the canal plane under test.

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

    Science.gov (United States)

    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.

  2. The impact of text repetition on content and function words during reading: further evidence from eye movements.

    Science.gov (United States)

    Chamberland, Cindy; Saint-Aubin, Jean; Légère, Marie-Andrée

    2013-06-01

    There is ample evidence that reading speed increases when participants read the same text more than once. However, less is known about the impact of text repetition as a function of word class. Some authors suggested that text repetition would mostly benefit content words with little or no effect on function words. In the present study, we examined the effect of multiple readings on the processing of content and function words. Participants were asked to read a short text two times in direct succession. Eye movement analyses revealed the typical multiple readings effect: Repetition decreased the time readers spent fixating words and the probability of fixating critical words. Most importantly, we found that the effect of multiple readings was of the same magnitude for content and function words, and for low- and high-frequency words. Such findings suggest that lexical variables have additive effects on eye movement measures in reading.

  3. Eye-movement strategies in developmental prosopagnosia and "super" face recognition.

    Science.gov (United States)

    Bobak, Anna K; Parris, Benjamin A; Gregory, Nicola J; Bennetts, Rachel J; Bate, Sarah

    2017-02-01

    Developmental prosopagnosia (DP) is a cognitive condition characterized by a severe deficit in face recognition. Few investigations have examined whether impairments at the early stages of processing may underpin the condition, and it is also unknown whether DP is simply the "bottom end" of the typical face-processing spectrum. To address these issues, we monitored the eye-movements of DPs, typical perceivers, and "super recognizers" (SRs) while they viewed a set of static images displaying people engaged in naturalistic social scenarios. Three key findings emerged: (a) Individuals with more severe prosopagnosia spent less time examining the internal facial region, (b) as observed in acquired prosopagnosia, some DPs spent less time examining the eyes and more time examining the mouth than controls, and (c) SRs spent more time examining the nose-a measure that also correlated with face recognition ability in controls. These findings support previous suggestions that DP is a heterogeneous condition, but suggest that at least the most severe cases represent a group of individuals that qualitatively differ from the typical population. While SRs seem to merely be those at the "top end" of normal, this work identifies the nose as a critical region for successful face recognition.

  4. The effect of eye movement and desensitization by reprocessing on depression in adolescents with Thalassemia

    Directory of Open Access Journals (Sweden)

    Shahnavazi

    2016-09-01

    Full Text Available Introduction: Thalassemia is the most common genetic diseases in the world and especially in our country. For many reasons, including chronic disease, health care costs, fear of early death, disease statues led to Depression, psychological and social problems in thalassemia patients. This study aimed to determine the efficacy of eye movement desensitization and processing efficiency of this method and to decreasing the Depression of children with thalassemia. Method: This study was a clinical trial. 60 thalassemic patients aged 20-12 years were randomly assigned to two groups. Demographic questionnaire and Beck Depression Inventory were used to collection of data. The trial of eye movement desensitization and reprocessing in 3 sessions on alternate days for 45 to 30 minutes after. Depression before and after the intervention were measured velocity. An analysis by descriptive statistics, t-test and paired t-test, Mann-Whitney and Wilcoxon tests Non parameter equal to the Kolmogorov-Smirnov test was performed. Results: This study shows that the mean or average level of Depression children with thalassemia before implementing EMDR therapy group27/73±3/52 was After doing EMDR therapy to 17/80±2/36 was Which is greatly reduced compared to pre-intervention and the results were statistically significant(P0<001. The result showed that EMDR has main full effect on decreasing the symptoms of Depression. Conclusion: The result showed that EMDR can useful through having the influence on integration information processing an effective method to treat or reduce Depression children with thalassemia.

  5. Speed matters: relationship between speed of eye movements and modification of aversive autobiographical memories

    Directory of Open Access Journals (Sweden)

    Suzanne Chantal Van Veen

    2015-04-01

    Full Text Available Eye Movement Desensitization and Reprocessing (EMDR is an efficacious treatment for posttraumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye movements (EM. Both tasks are considered to require limited working memory (WM resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. Currently, EMDR is a standardized treatment and patients typically receive the same dual task manipulation of 1 EM cycle per second (1 Hz. From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz and a low WM taxing EM frequency (slow EM; 0.8 Hz were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n=36 or three less vivid images (n=36 under each of three conditions: recall + fast EM, recall + slow EM or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for future research are discussed.

  6. Caffeine and central noradrenaline: effects on mood, cognitive performance, eye movements and cardiovascular function.

    Science.gov (United States)

    Smith, Andrew; Brice, Carolyn; Nash, Jon; Rich, Neil; Nutt, David J

    2003-09-01

    There have been numerous studies on the effects of caffeine on behaviour and cardiovascular function. It is now important to clarify the mechanisms that underlie such effects, and the main objective of the present study was to investigate whether changes in central noradrenaline underlie some of the behavioural and cardiovascular effects of caffeine. This was examined using a clonidine challenge paradigm. Twenty-four healthy volunteers were assigned to one of four conditions: (i) clonidine/caffeine; (ii) clonidine/placebo; (iii) placebo/caffeine: (iv) placebo/placebo. Baseline measurements of mood, cognitive performance, saccadic eye movements and cardiovascular function were recorded. Subsequently, volunteers were given either clonidine (200 microg) or placebo and consumed coffee containing caffeine (1.5 mg/kg) or placebo. The test battery was then repeated 30 min, 150 min and 270 min later. A second cup of coffee (with the same amount of caffeine as the first) was consumed 120 min after the first cup. The results showed that clonidine reduced alertness, impaired many aspects of performance and slowed saccadic eye movements; caffeine removed many of these impairments. Both clonidine and caffeine influenced blood pressure (clonidine reduced it, caffeine raised it) but the effects appeared to be independent, suggesting that separate mechanisms were involved. In addition, there were some behavioural effects of caffeine that were independent of the clonidine effect (e.g. effects on speed of encoding of new information) and these may reflect other neurotransmitter systems (e.g cholinergic effects). Overall, the results suggest that caffeine counteracts reductions in the turnover of central noradrenaline. This mechanism may underlie the beneficial effects of caffeine seen in low alertness states.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Malik M. Naeem Mannan

    2016-02-01

    Full Text Available 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.

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

    Science.gov (United States)

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

    2016-02-19

    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.

  10. Using Eye Movement Desensitization and Reprocessing To Enhance Treatment of Couples.

    Science.gov (United States)

    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…

  11. A Review of Eye Movement Desensitization and Reprocessing (EMDR): Research Findings and Implications for Counsellors.

    Science.gov (United States)

    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…

  12. A single-question screen for rapid eye movement sleep behavior disorder

    DEFF Research Database (Denmark)

    Postuma, Ronald B; Arnulf, Isabelle; Hogl, Birgit

    2012-01-01

    Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for Parkinson's disease (PD) and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large-scale epi...

  13. Relation between dream content and eye movements tested by lucid dreams.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-01-01

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

  15. Classification of iRBD and Parkinson's disease patients based on eye movements during sleep

    DEFF Research Database (Denmark)

    Christensen, Julie Anja Engelhard; Koch, Henriette; Frandsen, Rune;

    2013-01-01

    Patients suffering from the sleep disorder idiopathic rapid-eye-movement sleep behavior disorder (iRBD) have been observed to be in high risk of developing Parkinson's disease (PD). This makes it essential to analyze them in the search for PD biomarkers. This study aims at classifying patients...

  16. Conveying clinical reasoning based on visual observation via eye-movement modelling examples

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2012). Conveying clinical reasoning based on visual observation via eye-movement modelling examples. Instructional Science, 40(5), 813-827. doi:10.1007/s11251-012-9218-5

  17. Eye-Movement Patterns of Readers with Down Syndrome during Sentence-Processing: An Exploratory Study

    Science.gov (United States)

    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…

  18. Using Stroke Removal to Investigate Chinese Character Identification during Reading: Evidence from Eye Movements

    Science.gov (United States)

    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…

  19. Cataphora processing in agrammatic aphasia: Eye movement evidence for integration deficits

    Directory of Open Access Journals (Sweden)

    Chien-Ju Hsu

    2014-04-01

    These findings indicate that the patients exhibited similar eye-movement patterns to that of the controls when processing definitional-gender nouns. However, unlike controls, they failed to use contextual gender information to revise gender stereotypes. These patterns support the LIDH.

  20. Perception of Object-Context Relations: Eye-Movement Analyses in Infants and Adults

    Science.gov (United States)

    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…

  1. Conveying clinical reasoning based on visual observation via eye-movement modelling examples

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2012). Conveying clinical reasoning based on visual observation via eye-movement modelling examples. Instructional Science, 40(5), 813-827. doi:10.1007/s11251-012-9218-5

  2. A neural computation for visual acuity in the presence of eye movements.

    Directory of Open Access Journals (Sweden)

    Xaq Pitkow

    2007-12-01

    Full Text Available Humans can distinguish visual stimuli that differ by features the size of only a few photoreceptors. This is possible despite the incessant image motion due to fixational eye movements, which can be many times larger than the features to be distinguished. To perform well, the brain must identify the retinal firing patterns induced by the stimulus while discounting similar patterns caused by spontaneous retinal activity. This is a challenge since the trajectory of the eye movements, and consequently, the stimulus position, are unknown. We derive a decision rule for using retinal spike trains to discriminate between two stimuli, given that their retinal image moves with an unknown random walk trajectory. This algorithm dynamically estimates the probability of the stimulus at different retinal locations, and uses this to modulate the influence of retinal spikes acquired later. Applied to a simple orientation-discrimination task, the algorithm performance is consistent with human acuity, whereas naive strategies that neglect eye movements perform much worse. We then show how a simple, biologically plausible neural network could implement this algorithm using a local, activity-dependent gain and lateral interactions approximately matched to the statistics of eye movements. Finally, we discuss evidence that such a network could be operating in the primary visual cortex.

  3. Early and Late Processes in Syllogistic Reasoning: Evidence from Eye-Movements

    Science.gov (United States)

    Espino, Orlando; Santamaria, Carlos; Meseguer, Enrique; Carreiras, Manuel

    2005-01-01

    An eye-movement monitoring experiment was carried out to examine the effects of the difficulty of the problem (simple versus complex problems) and the type of figure (figure 1 or figure 4) on the time course of processing categorical syllogisms. The results showed that the course of influence for these two factors is different. We found early…

  4. Individual Differences in the Processing of Written Sarcasm and Metaphor: Evidence from Eye Movements

    Science.gov (United States)

    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…

  5. The impact of eye movements and tones on disturbing memories involving PTSD and other mental disorders

    NARCIS (Netherlands)

    de Jongh, A.; Ernst, R.; Marques, L.; Hornsveld, H.

    2013-01-01

    Background A wide array of experimental studies are supportive of a working memory explanation for the effects of eye movements in EMDR therapy. The working memory account predicts that, as a consequence of competition in working memory, traumatic memories lose their emotional charge. Method This

  6. Coregistration of Eye Movements and EEG in Natural Reading: Analyses and Review

    Science.gov (United States)

    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)…

  7. Eye Movements of Dyslexic Children when Reading in a Regular Orthography

    Science.gov (United States)

    Hutzler, Florian; Wimmer, Heinz

    2004-01-01

    Participants were German dyslexic readers (13-year-olds) who--compared to English dyslexic readers--suffer mainly from slow laborious reading and less from reading errors. The eye movements of eleven dyslexic boys and age-matched controls were recorded during reading of text passages and pseudoword lists. For both text and pseudoword reading, the…

  8. Reading Paths, Eye Drawings, and Word Islands: Movement in Un coup de dés

    Directory of Open Access Journals (Sweden)

    Ruth Loos

    2012-01-01

    Full Text Available In the framework of an artistic–scientific project on eye-movements during reading, my collaborators from the psychology department at the KU Leuven and I had a close look at the poem “Un coup de dés jamais n'abolira le hasard” (“A throw of the dice will never abolish chance” by Stéphane Mallarmé. The poem is an intriguing example of nonlinear writing, of a typographic game with white and space, and of an interweaving of different reading lines. These specific features evoke multiple reading methods. The animation, Movement in Un coup de dés, created during the still-ongoing collaboration interweaves a horizontal and a vertical reading method, two spontaneous ways of reading that point at the poem's intriguing ambiguity. Not only are we interested in different methods of reading; the scientific representations of eye movements themselves are a rich source of images with much artistic potential. We explore eye movements as “eye drawings” in new images characterized both by a scientific and by an artistic perspective.

  9. Children's Eye-Movements during Reading Reflect the Quality of Lexical Representations: An Individual Differences Approach

    Science.gov (United States)

    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…

  10. The influence of vertically and horizontally aligned visual distractors on aurally guided saccadic eye movements

    NARCIS (Netherlands)

    Ten Brink, A. F.; Nijboer, T. C W; Van Der Stoep, N.; Van Der Stigchel, S.

    2014-01-01

    Eye movements towards a new target can be guided or disrupted by input from multiple modalities. The degree of oculomotor competition evoked by a distractor depends on both distractor and target properties, such as distractor salience or certainty regarding the target location. The ability to locali

  11. The Eye Movement Desensitization and Reprocessing Procedure Prevents Defensive Processing in Health Persuasion

    NARCIS (Netherlands)

    Dijkstra, Arie; van Asten, Regine

    2014-01-01

    In the present study, the method of eye movement desensitization and reprocessing (EMDR) is studied to understand and prevent defensive reactions with regard to a negatively framed message advocating fruit and vegetable consumption. EMDR has been shown to tax the working memory. Participants from a

  12. Uncovering Expertise-Related Differences in Troubleshooting Performance: Combining Eye Movement and Concurrent Verbal Protocol Data

    NARCIS (Netherlands)

    Van Gog, Tamara; Paas, Fred; Van Merriënboer, Jeroen

    2007-01-01

    This study explored the value of eye movement data for uncovering relatively small expertise-related differences in electrical circuit-troubleshooting performance, and describes that value in relation to concurrent verbal protocols. Results show that in the ‘problem orientation’ phase, higher expert

  13. Pathological eye movements influence on the recordings of ocular vestibular-evoked myogenic potential.

    Science.gov (United States)

    Yang, Ting-Hua; Chen, Hsin-Lin; Young, Yi-Ho

    2017-08-01

    This study investigated the influence of pathological eye movements on the recordings of ocular vestibulo-evoked myogenic potential (oVEMP). Ten patients with pathological eye movements of non-vestibular origin (nine congenital nystagmus and one opsoclonus) who had negative MRI result were assigned to Group A. Another 20 vestibular neuritis (VN) patients with spontaneous nystagmus were assigned to Group B. Both groups underwent audiometry, and caloric, oVEMP and cervical VEMP (cVEMP) tests. In Group A, the caloric, oVEMP and cVEMP tests showed 40%, 55% and 50% abnormalities, respectively. In Group B (VN), caloric, oVEMP and cVEMP tests revealed 100%, 80% and 45% abnormalities on the lesion ears, and 0%, 40% and 0% abnormalities on the healthy (opposite) ears, respectively. The 40% oVEMP abnormality on the healthy ears may be due to recording failure from the presence of spontaneous nystagmus, since five of five VN patients showed normal oVEMPs on the healthy ears, one year after presentation. Presence of pathological eye movements may affect the recordings of oVEMP. Thus, the oVEMP test is recommended to perform after acute vertiginous episode to exclude the influence of pathological eye movements on the oVEMP recordings.

  14. Real-Time Control of a Video Game Using Eye Movements and Two Temporal EEG Sensors

    Directory of Open Access Journals (Sweden)

    Abdelkader Nasreddine Belkacem

    2015-01-01

    Full Text Available 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.

  15. Neuter is not Common in Dutch : Eye Movements Reveal Asymmetrical Gender Processing

    NARCIS (Netherlands)

    Loerts, Hanneke; Wieling, Martijn; Schmid, Monika S.

    2013-01-01

    Native speakers of languages with transparent gender systems can use gender cues to anticipate upcoming words. To examine whether this also holds true for a non-transparent two-way gender system, i.e. Dutch, eye movements were monitored as participants followed spoken instructions to click on one of

  16. The effect of visual field defects on eye movements and practical fitness to drive

    NARCIS (Netherlands)

    Coeckelbergh, TRM; Cornelissen, FW; Brouwer, WH; Kooijman, AC

    Eye movements Of Subjects with visual field defects due to ocular pathology were monitored while performing a dot counting task and a visual search task. Subjects with peripheral field defects required more fixations, longer search times, made more errors. and had shorter fixation durations than

  17. The effect of expertise on eye movement behaviour in medical image perception.

    Directory of Open Access Journals (Sweden)

    Raymond Bertram

    Full Text Available The present eye-movement study assessed the effect of expertise on eye-movement behaviour during image perception in the medical domain. To this end, radiologists, computed-tomography radiographers and psychology students were exposed to nine volumes of multi-slice, stack-view, axial computed-tomography images from the upper to the lower part of the abdomen with or without abnormality. The images were presented in succession at low, medium or high speed, while the participants had to detect enlarged lymph nodes or other visually more salient abnormalities. The radiologists outperformed both other groups in the detection of enlarged lymph nodes and their eye-movement behaviour also differed from the other groups. Their general strategy was to use saccades of shorter amplitude than the two other participant groups. In the presence of enlarged lymph nodes, they increased the number of fixations on the relevant areas and reverted to even shorter saccades. In volumes containing enlarged lymph nodes, radiologists' fixation durations were longer in comparison to their fixation durations in volumes without enlarged lymph nodes. More salient abnormalities were detected equally well by radiologists and radiographers, with both groups outperforming psychology students. However, to accomplish this, radiologists actually needed fewer fixations on the relevant areas than the radiographers. On the basis of these results, we argue that expert behaviour is manifested in distinct eye-movement patterns of proactivity, reactivity and suppression, depending on the nature of the task and the presence of abnormalities at any given moment.

  18. Visual perception in fencing: do the eye movements of fencers represent their information pickup?

    Science.gov (United States)

    Hagemann, Norbert; Schorer, Jörg; Cañal-Bruland, Rouwen; Lotz, Simone; Strauss, Bernd

    2010-11-01

    The present study examined whether results of athletes' eye movements while they observe fencing attacks reflect their actual information pickup by comparing these results with others gained with temporal and spatial occlusion and cuing techniques. Fifteen top-ranking expert fencers, 15 advanced fencers, and 32 sport students predicted the target region of 405 fencing attacks on a computer monitor. Results of eye movement recordings showed a stronger foveal fixation on the opponent's trunk and weapon in the two fencer groups. Top-ranking expert fencers fixated particularly on the upper trunk. This matched their performance decrements in the spatial occlusion condition. However, when the upper trunk was occluded, participants also shifted eye movements to neighboring body regions. Adding cues to the video material had no positive effects on prediction performance. We conclude that gaze behavior does not necessarily represent information pickup, but that studies applying the spatial occlusion paradigm should also register eye movements to avoid underestimating the information contributed by occluded regions.

  19. Eye movements during the recollection of text information reflect content rather than the text itself

    DEFF Research Database (Denmark)

    Traub, Franziska; Johansson, Roger; Holmqvist, Kenneth

    Several studies have reported that spontaneous eye movements occur when visuospatial information is recalled from memory. Such gazes closely reflect the content and spatial relations from the original scene layout (e.g., Johansson et al., 2012). However, when someone has originally read a scene...

  20. Eye Movements and Word Skipping during Reading: Effects of Word Length and Predictability

    Science.gov (United States)

    Rayner, Keith; Slattery, Timothy J.; Drieghe, Denis; Liversedge, Simon P.

    2011-01-01

    Eye movements were monitored as subjects read sentences containing high- or low-predictable target words. The extent to which target words were predictable from prior context was varied: Half of the target words were predictable, and the other half were unpredictable. In addition, the length of the target word varied: The target words were short…

  1. Plausibility Effects when Reading One- and Two-Character Words in Chinese: Evidence from Eye Movements

    Science.gov (United States)

    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…

  2. Can changes in eye movement scanning alter the age-related deficit in recognition memory?

    Directory of Open Access Journals (Sweden)

    Jessica P.K. Chan

    2011-05-01

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

  3. Complement Coercion Is Not Modulated by Competition: Evidence from Eye Movements

    Science.gov (United States)

    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 …

  4. COMT val(158)met genotype and smooth pursuit eye movements in schizophrenia

    DEFF Research Database (Denmark)

    Haraldsson, H Magnus; Ettinger, Ulrich; Magnusdottir, Brynja B;

    2009-01-01

    The association between the catechol-O-methyltransferase (COMT) val(158)met polymorphism (rs4680) and smooth pursuit eye movements (SPEM) was investigated in 110 schizophrenia patients and 96 controls. Patients had lower steady-state pursuit gain and made more frequent saccades than controls...

  5. Eye Movement Behaviour during Reading of Japanese Sentences: Effects of Word Length and Visual Complexity

    Science.gov (United States)

    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…

  6. Children's Eye-Movements during Reading Reflect the Quality of Lexical Representations: An Individual Differences Approach

    Science.gov (United States)

    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…

  7. Readers in Adult Basic Education: Component Skills, Eye Movements, and Fluency

    Science.gov (United States)

    Barnes, Adrienne E.; Kim, Young-Suk; Tighe, Elizabeth L.; Vorstius, Christian

    2017-01-01

    The present study explored the reading skills of a sample of 48 adults enrolled in a basic education program in northern Florida, United States. Previous research has reported on reading component skills for students in adult education settings, but little is known about eye movement patterns or their relation to reading skills for this…

  8. Effects of Saccadic Bilateral Eye Movements on Memory in Children and Adults: An Exploratory Study

    Science.gov (United States)

    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…

  9. Rapid eye movement sleep behavior disorder--diagnostik, årsager og behandling

    DEFF Research Database (Denmark)

    Zoetmulder, Marielle; Jennum, Poul Jørgen

    2009-01-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by loss of REM sleep and related electromyographic atonia with marked muscular activity and dream enactment behaviour. RBD is seen in 0.5% of the population. It occurs in an idiopathic form and secondarily to medical and neu...

  10. Readers in Adult Basic Education: Component Skills, Eye Movements, and Fluency

    Science.gov (United States)

    Barnes, Adrienne E.; Kim, Young-Suk; Tighe, Elizabeth L.; Vorstius, Christian

    2017-01-01

    The present study explored the reading skills of a sample of 48 adults enrolled in a basic education program in northern Florida, United States. Previous research has reported on reading component skills for students in adult education settings, but little is known about eye movement patterns or their relation to reading skills for this…

  11. Eye Movements Reveal Students' Strategies in Simple Equation Solving

    Science.gov (United States)

    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…

  12. Hawk eyes II: diurnal raptors differ in head movement strategies when scanning from perches.

    Directory of Open Access Journals (Sweden)

    Colleen T O'Rourke

    Full Text Available 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.

  13. Human Response to Ductless Personalised Ventilation: Impact of Air Movement, Temperature and Cleanness on Eye Symptoms

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Fillon, Maelys; Bivolarova, Maria;

    2013-01-01

    The performance of ductless personalized ventilation (DPV) in conjunction with displacement ventilation (DV) was studied in relation to peoples’ health, comfort and performance. This paper presents results on the impact of room air temperature, using of DPV and local air filtration on eye blink...... rate and tear film quality. In a test room with DV and six workstations 30 human subjects were exposed for four hours to each of the following 5 experimental conditions: 23 °C and DV only, 23 °C and DPV with air filter, 29 °C and DV only, 29 °C and DPV, and 29 °C and DPV with air filter. At warm...... environment facially applied individually controlled air movement of room air, with or without local filtering, did not have significant impact on eye blink frequency and tear film quality. The local air movement and air cleaning resulted in increased eye blinking frequency and improvement of tear film...

  14. An Evaluation of Educational Neurological Eye Movement Disorder Videos Posted on Internet Video Sharing Sites.

    Science.gov (United States)

    Hickman, Simon J

    2016-03-01

    Internet video sharing sites allow the free dissemination of educational material. This study investigated the quality and educational content of videos of eye movement disorders posted on such sites. Educational neurological eye movement videos were identified by entering the titles of the eye movement abnormality into the search boxes of the video sharing sites. Also, suggested links were followed from each video. The number of views, likes, and dislikes for each video were recorded. The videos were then rated for their picture and sound quality. Their educational value was assessed according to whether the video included a description of the eye movement abnormality, the anatomical location of the lesion (if appropriate), and the underlying diagnosis. Three hundred fifty-four of these videos were found on YouTube and Vimeo. There was a mean of 6,443 views per video (range, 1-195,957). One hundred nineteen (33.6%) had no form of commentary about the eye movement disorder shown apart from the title. Forty-seven (13.3%) contained errors in the title or in the text. Eighty (22.6%) had excellent educational value by describing the eye movement abnormality, the anatomical location of the lesion, and the underlying diagnosis. Of these, 30 also had good picture and sound quality. The videos with excellent educational value had a mean of 9.84 "likes" per video compared with 2.37 for those videos without a commentary (P educational value with good picture and sound quality had a mean of 10.23 "likes" per video (P = 0.004 vs videos with no commentary). There was no significant difference in the mean number of "dislikes" between those videos that had no commentary or which contained errors and those with excellent educational value. There are a large number of eye movement videos freely available on these sites; however, due to the lack of peer review, a significant number have poor educational value due to having no commentary or containing errors. The number of "likes

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

    Science.gov (United States)

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

    2010-07-01

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

  16. Rapid eye movement sleep disturbances in Huntington disease

    DEFF Research Database (Denmark)

    Arnulf, I.; Nielsen, J.; Lohmann, E.

    2008-01-01

    with very mild HD and worsened with disease severity. In contrast to narcoleptic patients, HD patients had no cataplexy, hypnagogic hallucinations, or sleep paralysis. Four HD patients had abnormally low (sleep latencies, but none had multiple sleep-onset REM periods. Conclusions......Background: Sleep disorders including insomnia, movements during sleep, and daytime sleepiness are common but poorly studied in Huntington disease (HD). Objective: To evaluate the HD sleep-wake phenotype (including abnormal motor activity during sleep) in patients with various HD stages...... interview, nighttime video and sleep monitoring, and daytime multiple sleep latency tests. Their results were compared with those of patients with narcolepsy and control patients. Results: The HD patients had frequent insomnia, earlier sleep onset, lower sleep efficiency, increased stage I sleep, delayed...

  17. How memory mechanisms are a key component in the guidance of our eye movements : Evidence from the global effect

    NARCIS (Netherlands)

    Silvis, J. D.; Van der Stigchel, S.

    2014-01-01

    Investigating eye movements has been a promising approach to uncover the role of visual working memory in early attentional processes. Prior research has already demonstrated that eye movements in search tasks are more easily drawn toward stimuli that show similarities to working memory content, as

  18. Individual Differences in Fifth Graders' Literacy and Academic Language Predict Comprehension Monitoring Development: An Eye-Movement Study

    Science.gov (United States)

    Connor, Carol McDonald; Radach, Ralph; Vorstius, Christian; Day, Stephanie L.; McLean, Leigh; Morrison, Frederick J.

    2015-01-01

    In this study, we investigated fifth graders' (n = 52) fall literacy, academic language, and motivation and how these skills predicted fall and spring comprehension monitoring on an eye movement task. Comprehension monitoring was defined as the identification and repair of misunderstandings when reading text. In the eye movement task, children…

  19. Eye Movements during Scene Recollection Have a Functional Role, but They Are Not Reinstatements of Those Produced during Encoding

    Science.gov (United States)

    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…

  20. Eye movements reveal fast, voice-specific priming.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. An Eye Movement Pre-Training Fosters the Comprehension of Processes and Functions in Technical Systems

    Directory of Open Access Journals (Sweden)

    Irene Therese Skuballa

    2015-05-01

    Full Text Available The main research goal of the present study was to investigate in how far pre-training eye movements can promote 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 which moved in close spatial resemblance to a to-be-learned learning environment, namely a static visualization of a solar plant accompanied by a narration. This training was expected to foster top-down processes as reflected in gaze behavior during the learning process and better knowledge. We compared two groups (N = 45: participants in the experimental condition received such pre-training in a first step and processed the learning material in a second step, whereas the control underwent the second step without any pre-training. The pre-training group outperformed the no-training group in their learning outcomes, particularly in knowledge about the 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 the learners’ eye movement behavior during learning.

  3. Characteristic visuomotor influences on eye-movement patterns to faces and other high level stimuli

    Directory of Open Access Journals (Sweden)

    Joseph Michael Arizpe

    2015-07-01

    Full Text Available 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, 16 degrees 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.

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

    Science.gov (United States)

    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

  5. Saccadic and smooth-pursuit eye movements during reading of drifting texts.

    Science.gov (United States)

    Valsecchi, Matteo; Gegenfurtner, Karl R; Schütz, Alexander C

    2013-08-16

    Reading is a complex visuomotor behavior characterized by an alternation of fixations and saccadic eye movements. Despite the widespread use of drifting texts in various settings, very little is known about eye movements under these conditions. Here we investigated oculomotor behavior during reading of texts which were drifting horizontally or vertically at different speeds. Consistent with previous reports, drifting texts were read by an alternation of smooth-pursuit and saccadic eye movements. Detailed analysis revealed several interactions between smooth pursuit and saccades. On one side, the gain of smooth pursuit was increased after the execution of a saccade. On the other side, the peak velocity of saccades was reduced for the horizontally drifting text, in which saccades and pursuit were executed in opposite directions. In addition, we show that well-known findings from the reading of static texts extend to drifting text, such as the preferred viewing location, the inverted optimal viewing position, and the correlation between saccade amplitude and subsequent pursuit/fixation duration. In general, individual eye-movement parameters such as saccade amplitude and fixation/pursuit durations were correlated across self-paced reading of static text and time-constrained reading of static and drifting texts. These results show that findings from basic oculomotor research also apply to the reading of drifting texts. Similarly, basic reading principles apply to the reading of static and drifting texts in a similar way. This exemplifies the reading of drifting text as a visuomotor behavior which is influenced by low-level eye-movement control as well as by cognitive and linguistic processing.

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

    Science.gov (United States)

    Lee, Samantha Sze-Yee; Black, Alex A; Wood, Joanne M

    2017-01-01

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

  7. The analysis of the influence of fractal structure of stimuli on fractal dynamics in fixational eye movements and EEG signal

    Science.gov (United States)

    Namazi, Hamidreza; Kulish, Vladimir V.; Akrami, Amin

    2016-01-01

    One of the major challenges in vision research is to analyze the effect of visual stimuli on human vision. However, no relationship has been yet discovered between the structure of the visual stimulus, and the structure of fixational eye movements. This study reveals the plasticity of human fixational eye movements in relation to the ‘complex’ visual stimulus. We demonstrated that the fractal temporal structure of visual dynamics shifts towards the fractal dynamics of the visual stimulus (image). The results showed that images with higher complexity (higher fractality) cause fixational eye movements with lower fractality. Considering the brain, as the main part of nervous system that is engaged in eye movements, we analyzed the governed Electroencephalogram (EEG) signal during fixation. We have found out that there is a coupling between fractality of image, EEG and fixational eye movements. The capability observed in this research can be further investigated and applied for treatment of different vision disorders. PMID:27217194

  8. The analysis of the influence of fractal structure of stimuli on fractal dynamics in fixational eye movements and EEG signal

    Science.gov (United States)

    Namazi, Hamidreza; Kulish, Vladimir V.; Akrami, Amin

    2016-05-01

    One of the major challenges in vision research is to analyze the effect of visual stimuli on human vision. However, no relationship has been yet discovered between the structure of the visual stimulus, and the structure of fixational eye movements. This study reveals the plasticity of human fixational eye movements in relation to the ‘complex’ visual stimulus. We demonstrated that the fractal temporal structure of visual dynamics shifts towards the fractal dynamics of the visual stimulus (image). The results showed that images with higher complexity (higher fractality) cause fixational eye movements with lower fractality. Considering the brain, as the main part of nervous system that is engaged in eye movements, we analyzed the governed Electroencephalogram (EEG) signal during fixation. We have found out that there is a coupling between fractality of image, EEG and fixational eye movements. The capability observed in this research can be further investigated and applied for treatment of different vision disorders.

  9. Processing grammatical gender in Dutch: Evidence from eye movements.

    Science.gov (United States)

    Brouwer, Susanne; Sprenger, Simone; Unsworth, Sharon

    2017-07-01

    Previous research has demonstrated that grammatical gender in Dutch is typically acquired late. Most of this work used production data only, and consequently children's knowledge of Dutch gender may have been underestimated. In this study, therefore, we examined whether 49 4- to 7-year-old Dutch-speaking children (and 19 adult controls) were able to use gender marking in the article preceding the object label during online sentence processing to (a) anticipate the upcoming object label or to (b) facilitate the processing of that label as it is presented. In addition, we investigated whether children's online processing and production of gender marking on articles were related. In an eye-tracking task, participants were presented with sentences and visual displays with two objects, representing nouns of either the same gender (uninformative) or different genders (informative). Children were divided into a non-targetlike group and a targetlike group on the basis of their scores for neuter nouns in the production task. Our analyses examined whether participants could use gender marking anticipatorily (i.e., before the onset of the noun) and facilitatively (i.e., from noun onset). Results showed that Dutch-speaking adults and children who were successful in production used gender marking anticipatorily. However, children who did not systematically produce gender-marked articles used gender marking only facilitatively. These findings reveal that successful online comprehension may in part be possible before targetlike production is completely in place, but at the same time targetlike production may be a trigger for online comprehension to be completely successful. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Using Eye Movements to Assess Language Comprehension in Toddlers Born Preterm and Full Term.

    Science.gov (United States)

    Loi, Elizabeth C; Marchman, Virginia A; Fernald, Anne; Feldman, Heidi M

    2017-01-01

    To assess language skills in children born preterm and full term by the use of a standardized language test and eye-tracking methods. Children born ≤32 weeks' gestation (n = 44) were matched on sex and socioeconomic status to children born full term (n = 44) and studied longitudinally. The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) were administered at 18 months (corrected for prematurity as applicable). The Looking-While-Listening Task (LWL) simultaneously presents 2 pictures and an auditory stimulus that directs the child's attention to one image. The pattern of eye movements reflects visual processing and the efficiency of language comprehension. Children born preterm were evaluated on LWL 3 times between 18 and 24 months. Children born full term were evaluated at ages corresponding to chronological and corrected ages of their preterm match. Results were compared between groups for the BSID-III and 2 LWL measures: accuracy (proportion of time looking at target) and reaction time (latency to shift gaze from distracter to target). Children born preterm had lower BSID-III scores than children born full term. Children born preterm had poorer performance than children born full term on LWL measures for chronological age but similar performance for corrected age. Accuracy and reaction time at 18 months' corrected age displaced preterm-full term group membership as significant predictors of BSID-III scores. Performance and rate of change on language comprehension measures were similar in children born preterm and full term compared at corrected age. Individual variation in language comprehension efficiency was a robust predictor of scores on a standardized language assessment in both groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A guideline for integrating dynamic areas of interests in existing set-up for capturing eye movement: Looking at moving aircraft.

    Science.gov (United States)

    Friedrich, Maik; Rußwinkel, Nele; Möhlenbrink, Christoph

    2016-06-10

    Today, capturing the behavior of a human eye is considered a standard method for measuring the information-gathering process and thereby gaining insights into cognitive processes. Due to the dynamic character of most task environments there is still a lack of a structured and automated approach for analyzing eye movement in combination with moving objects. In this article, we present a guideline for advanced gaze analysis, called IGDAI (Integration Guideline for Dynamic Areas of Interest). The application of IGDAI allows gathering dynamic areas of interest and simplifies its combination with eye movement. The first step of IGDAI defines the basic requirements for the experimental setup including the embedding of an eye tracker. The second step covers the issue of storing the information of task environments for the dynamic AOI analysis. Implementation examples in XML are presented fulfilling the requirements for most dynamic task environments. The last step includes algorithms to combine the captured eye movement and the dynamic areas of interest. A verification study was conducted, presenting an air traffic controller environment to participants. The participants had to distinguish between different types of dynamic objects. The results show that in comparison to static areas of interest, IGDAI allows a faster and more detailed view on the distribution of eye movement.

  12. Real-time recording and classification of eye movements in an immersive virtual environment.

    Science.gov (United States)

    Diaz, Gabriel; Cooper, Joseph; Kit, Dmitry; Hayhoe, Mary

    2013-10-10

    Despite the growing popularity of virtual reality environments, few laboratories are equipped to investigate eye movements within these environments. This primer is intended to reduce the time and effort required to incorporate eye-tracking equipment into a virtual reality environment. We discuss issues related to the initial startup and provide algorithms necessary for basic analysis. Algorithms are provided for the calculation of gaze angle within a virtual world using a monocular eye-tracker in a three-dimensional environment. In addition, we provide algorithms for the calculation of the angular distance between the gaze and a relevant virtual object and for the identification of fixations, saccades, and pursuit eye movements. Finally, we provide tools that temporally synchronize gaze data and the visual stimulus and enable real-time assembly of a video-based record of the experiment using the Quicktime MOV format, available at http://sourceforge.net/p/utdvrlibraries/. This record contains the visual stimulus, the gaze cursor, and associated numerical data and can be used for data exportation, visual inspection, and validation of calculated gaze movements.

  13. Effect of repetition proportion on language-driven anticipatory eye movements

    Science.gov (United States)

    Britt, Allison E.; Mirman, Daniel; Kornilov, Sergey A.; Magnuson, James S.

    2014-01-01

    Previous masked priming research in word recognition has demonstrated that repetition priming is influenced by experiment-wise information structure, such as proportion of target repetition. Research using naturalistic tasks and eye-tracking has shown that people use linguistic knowledge to anticipate upcoming words. We examined whether the proportion of target repetition within an experiment can have a similar effect on anticipatory eye movements. We used a word-to-picture matching task (i.e., the visual world paradigm) with target repetition proportion carefully controlled. Participants’ eye movements were tracked starting when the pictures appeared, one second prior to the onset of the target word. Targets repeated from the previous trial were fixated more than other items during this preview period when target repetition proportion was high and less than other items when target repetition proportion was low. These results indicate that linguistic anticipation can be driven by short-term within-experiment trial structure, with implications for the generalization of priming effects, the bases of anticipatory eye movements, and experiment design. PMID:24345674

  14. Williams syndrome and its cognitive profile: the importance of eye movements

    Directory of Open Access Journals (Sweden)

    Van Herwegen J

    2015-06-01

    Full Text Available Jo Van Herwegen Department of Psychology, Kingston University London, Surrey, UK Abstract: 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. Keywords: Williams syndrome, eye movements, face processing, language, number, visuospatial abilities

  15. Analyzing the Stimulus Control Acquisition in Simple Discrimination Tasks through Eye Movement

    Directory of Open Access Journals (Sweden)

    Edson Massayuki Huziwara

    2015-09-01

    Full Text Available In order to investigate whether simultaneous or successive presentation of stimuli is related to the duration of eye fixation (i.e., the time spent gazing a specific stimulus, this study described the eye movements of young adults in simultaneous and successive simple discrimination tasks. Using 12 landscape scenes as visual stimuli, three participants were exposed to a simple discrimination training with simultaneously presented stimuli (Si Procedure and then to a second simple discrimination training with successively presented stimuli (Su Procedure. Another three participants were exposed to the Procedure in the opposite order. In both cases, the learning criterion was that at least 90% of the responses should be correct in one block. Eye movements were recorded during the whole experiment. Participants achieved the learning criteria in both procedures. Beyond that, eye fixation time in the Su Procedure was higher than in the Si Procedure, regardless of the training sequence. Taken together with previous results in different experiments, our findings suggest that the duration of eye fixation plays a central role in the establishment of different stimulus control topographies.

  16. Eye movements and manual interception of ballistic trajectories: effects of law of motion perturbations and occlusions.

    Science.gov (United States)

    Delle Monache, Sergio; Lacquaniti, Francesco; Bosco, Gianfranco

    2015-02-01

    Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects' head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth's gravity or perturbed with weightlessness (0 g) or hypergravity (2 g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects' oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets' laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets' laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target's tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kovesdi, Casey Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rice, Brandon Charles [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bower, Gordon Ross [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spielman, Zachary Alexander [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hill, Rachael Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States); LeBlanc, Katya Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-11-01

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

  18. Comparison of eye movements over faces in photographic positives and negatives.

    Science.gov (United States)

    Luria, Saul M; Strauss, Mark S

    2013-01-01

    Eye movements were recorded while subjects viewed ordinary portraits and photographic negatives of those portraits. Under both conditions they first studied sixteen portraits and then tried to decide which of forty-eight portraits they had just seen. They made more errors of recognition while viewing negatives, and their fixation patterns were significantly altered: there was a decrease in the percentage of fixations directed to the eyes, nose, and mouth, and an increase for such details as the ears, cheeks, chin, cap, and necktie. There was also a decrease in the ratio of fixations to the most fixated detail compared to the least fixated detail.

  19. Measurement of eye size illusion caused by eyeliner, mascara, and eye shadow.

    Science.gov (United States)

    Matsushita, Soyogu; Morikawa, Kazunori; Yamanami, Haruna

    2015-01-01

    Do eyeliner, mascara, and eye shadow actually make the eyes appear larger than they really are? If so, by what percentage? To answer these questions, we used psychophysical experiments. Experiment 1 manipulated the degree of eyeliner (four levels) and mascara (five levels), and measured perceived eye size using a psychophysical procedure called the staircase method. The results showed that both eyeliner and mascara make the eyes appear larger than they really are by up to 6% (13% in area), but their effects are not additive. Eyeliner increased perceived eye size only in the absence of mascara. In the presence of mascara, however, eyeliner has no additional effect. Experiment 2 measured perceived eye size with or without eye shadow and demonstrated that eye shadow increases perceived eye size by about 5% (10% in area). These findings indicate that one mechanism by which makeup and cosmetics alter facial appearances involves inducing visual illusions. In addition, it is suggested that the eye size illusion caused by eyeliner, mascara, and eye shadow uses the same mechanism as that of the Delboeuf illusion, a geometric illusion of assimilation.

  20. Degrading traumatic memories with eye movements: a pilot functional MRI study in PTSD

    Directory of Open Access Journals (Sweden)

    Kathleen Thomaes

    2016-11-01

    Full Text Available Background: Eye movement desensitization and reprocessing (EMDR is an effective treatment for posttraumatic stress disorder (PTSD. During EMDR, the patient recalls traumatic memories while making eye movements (EMs. Making EMs during recall is associated with decreased vividness and emotionality of traumatic memories, but the underlying mechanism has been unclear. Recent studies support a “working-memory” (WM theory, which states that the two tasks (recall and EMs compete for limited capacity of WM resources. However, prior research has mainly relied on self-report measures. Methods: Using functional magnetic resonance imaging, we tested whether “recall with EMs,” relative to a “recall-only” control condition, was associated with reduced activity of primary visual and emotional processing brain regions, associated with vividness and emotionality respectively, and increased activity of the dorsolateral prefrontal cortex (DLPFC, associated with working memory. We used a randomized, controlled, crossover experimental design in eight adult patients with a primary diagnosis of PTSD. A script-driven imagery (SDI procedure was used to measure responsiveness to an audio-script depicting the participant's traumatic memory before and after conditions. Results: SDI activated mainly emotional processing-related brain regions (anterior insula, rostral anterior cingulate cortex (ACC, and dorsomedial prefrontal cortex, WM-related (DLPFC, and visual (association brain regions before both conditions. Although predicted pre- to post-test decrease in amygdala activation after “recall with EMs” was not significant, SDI activated less right amygdala and rostral ACC activity after “recall with EMs” compared to post-“recall-only.” Furthermore, functional connectivity from the right amygdala to the rostral ACC was decreased after “recall with EMs” compared with after “recall-only.” Conclusions: These preliminary results in a small sample

  1. Are altered smooth pursuit eye movements related to chronic pain and disability following whiplash injuries? A prospective trial with one-year follow-up

    DEFF Research Database (Denmark)

    Kongsted, Alice; Jørgensen, Lars Vincents; Leboeuf-Yde, Charlotte

    2008-01-01

    -year follow-up. SETTING: The study was carried out at a university research centre and participants were recruited from emergency units and general practitioners. SUBJECTS: In all, 262 participants were recruited within 10 days from a whiplash injury. MAIN MEASURES: Smooth pursuit eye movements were tested......OBJECTIVE: To evaluate the ability of early smooth pursuit testing to predict chronic whiplash-associated disorders, and to study whether the presence of abnormal smooth pursuit eye movements at one-year follow-up is associated with symptoms at that time. DESIGN: Prospective cohort study with one...... collision were determined. RESULTS: Results of early eye movement tests were not associated with the prognosis. Reduced smooth pursuit performance when tested in static cervical rotation at the one-year follow-up was significantly associated with higher neck pain intensity at that time (regression...

  2. Eye movements in pedophiles: automatic and controlled attentional processes while viewing prepubescent stimuli.

    Science.gov (United States)

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

    2013-05-01

    Recent theories in sexuality highlight the importance of automatic and controlled attentional processes in viewing sexually relevant stimuli. The model of Spiering and Everaerd (2007) assumes that sexually relevant features of a stimulus are preattentively selected and automatically induce focal attention to these sexually relevant aspects. Whether this assumption proves true for pedophiles is unknown. It is aim of this study to test this assumption empirically for people suffering from pedophilic interests. Twenty-two pedophiles, 8 nonpedophilic forensic controls, and 52 healthy controls simultaneously viewed the picture of a child and the picture of an adult while eye movements were measured. Entry time was assessed as a measure of automatic attentional processes and relative fixation time in order to assess controlled attentional processes. Pedophiles demonstrated significantly shorter entry time to child stimuli than to adult stimuli. The opposite was the case for nonpedophiles, as they showed longer relative fixation time for adult stimuli, and, against all expectations, pedophiles also demonstrated longer relative fixation time for adult stimuli. The results confirmed the hypothesis that pedophiles automatically selected sexually relevant stimuli (children). Contrary to all expectations, this automatic selection did not trigger the focal attention to these sexually relevant pictures. Furthermore, pedophiles were first and longest attracted by faces and pubic regions of children; nonpedophiles were first and longest attracted by faces and breasts of adults. The results demonstrated, for the first time, that the face and pubic region are the most attracting regions in children for pedophiles.

  3. Illusory position shift induced by motion within a moving envelope during smooth-pursuit eye movements.

    Science.gov (United States)

    Hisakata, Rumi; Terao, Masahiko; Murakami, Ikuya

    2013-10-30

    The static envelope of a Gabor patch with a moving carrier appears to shift in the direction of the carrier motion; this phenomenon is known as the motion-induced position shift (De Valois & De Valois, 1991; Ramachandran & Anstis, 1990). This conventional stimulus configuration contains at least three covarying factors: the retinal carrier velocity, the environmental carrier velocity, and the carrier velocity relative to the envelope velocity, which happens to be zero. We manipulated these velocities independently to identify which is critical, and we measured the perceived position of the moving Gabor patch relative to a reference stimulus moving in the same direction at the same speed. In the first experiment, the position of the moving envelope observed with fixation appeared to shift in the direction of the carrier velocity relative to the envelope velocity. Furthermore, the illusion was more pronounced when the carrier moved in a direction opposite to that of the envelope. In the second and third experiments, we measured the illusion during smooth-pursuit eye movement in which the envelope was either static or moving, thereby dissociating retinal and environmental velocities. Under all conditions, the illusion occurred according to the envelope-relative velocity of the carrier. Additionally, the illusion was more pronounced when the carrier and envelope moved in opposite directions. We conclude that the carrier's envelope-relative velocity is the primary determinant of the motion-induced position shift.

  4. The effect of character contextual diversity on eye movements in Chinese sentence reading.

    Science.gov (United States)

    Chen, Qingrong; Zhao, Guoxia; Huang, Xin; Yang, Yiming; Tanenhaus, Michael K

    2017-03-30

    Chen, Huang, et al. (Psychonomic Bulletin & Review, 2017) found that when reading two-character Chinese words embedded in sentence contexts, contextual diversity (CD), a measure of the proportion of texts in which a word appears, affected fixation times to words. When CD is controlled, however, frequency did not affect reading times. Two experiments used the same experimental designs to examine whether there are frequency effects of the first character of two-character words when CD is controlled. In Experiment 1, yoked triples of characters from a control group, a group matched for character CD that is lower in frequency, and a group matched in frequency with the control group, but higher in character CD, were rotated through the same sentence frame. In Experiment 2 each character from a larger set was embedded in a separate sentence frame, allowing for a larger difference in log frequency compared to Experiment 1 (0.8 and 0.4, respectively). In both experiments, early and later eye movement measures were significantly shorter for characters with higher CD than for characters with lower CD, with no effects of character frequency. These results place constraints on models of visual word recognition and suggest ways in which Chinese can be used to tease apart the nature of context effects in word recognition and language processing in general.

  5. Activation of the motor cortex during phasic rapid eye movement sleep

    Science.gov (United States)

    De Carli, Fabrizio; Proserpio, Paola; Morrone, Elisa; Sartori, Ivana; Ferrara, Michele; Gibbs, Steve Alex; De Gennaro, Luigi; Lo Russo, Giorgio

    2016-01-01

    When dreaming during rapid eye movement (REM) sleep, we can perform complex motor behaviors while remaining motionless. How the motor cortex behaves during this state remains unknown. Here, using intracerebral electrodes sampling the human motor cortex in pharmacoresistant epileptic patients, we report a pattern of electroencephalographic activation during REM sleep similar to that observed during the performance of a voluntary movement during wakefulness. This pattern is present during phasic REM sleep but not during tonic REM sleep, the latter resembling relaxed wakefulness. This finding may help clarify certain phenomenological aspects observed in REM sleep behavior disorder. Ann Neurol 2016;79:326–330 PMID:26575212

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Magdalena Krieber

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

  8. Recent data on rapid eye movement sleep behavior disorder in patients with Parkinson disease: analysis of behaviors, movements, and periodic limb movements.

    Science.gov (United States)

    Cochen De Cock, Valérie

    2013-08-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a fascinating parasomnia in which patients are able to enact their dreams because of a lack of muscle atonia during REM sleep. RBD represents a unique window into the dream world. Frequently associated with Parkinson's disease (PD), RBD raises various issues about dream modifications in this pathology and about aggressiveness during RBD episodes in placid patients during wakefulness. Studies on these behaviors have underlined their non-stereotyped, action-filled and violent characteristics but also their isomorphism with dream content. Complex, learnt behaviors may reflect the cortical involvement in this parasomnia but the more frequent elementary movements and the associated periodic limb movements during sleep also implicate the brainstem. Surprisingly, patients with PD have an improvement of their movements during their RBD as if they were disease-free. Also not yet understood, this improvement of movement during REM sleep raises issues about the pathways involved in RBD and about the possibility of using this pathway to improve movement in PD during the day.

  9. [Psychotherapeutic treatment of traumatic stress with the EMDR (Eye Movement Desensitization and Reprocessing) method].

    Science.gov (United States)

    Liebermann, P; Hofmann, A; Flatten, G

    2003-12-04

    EMDR (Eye Movement Desensitization and Reprocessing) is a method, developed at the end of the nineteen-eighties, for the treatment of the post-traumatic stress disorder (PTSD). The patient is asked to concentrate on certain aspect of the traumatic memory while keeping his eyes fixed on the movements of the therapist's finger. Apparently, this triggers information processing that results in appreciable relief for the patient. The method has proven to be equally as effective as behavioral-therapeutic techniques, and, has in the meantime, been included in national and international guidelines for the treatment of PTSD. The indications for EMDR treatment include not only PTSD, but, increasingly, also other, sometimes more severely chronic, it trauma sequelae. Within the framework of basic care, EMDR must be embedded within a treatment plan and should, where applicable, be combined with other methods.

  10. Eye movement desensitization and reprocessing (EMDR) in the treatment of war veterans.

    Science.gov (United States)

    Silver, Steven M; Rogers, Susan; Russell, Mark

    2008-08-01

    Recent practice guidelines and meta-analyses have designated eye movement desensitization and reprocessing (EMDR) as a first-line treatment for trauma. Eye movement desensitization and reprocessing is an eight-phase therapeutic approach guided by an information-processing model that addresses the combat veteran's critical incidents, current triggers, and behaviors likely to prove useful in his or her future. Two case examples of combat veterans illustrate the ability of EMDR to achieve symptom reduction in a variety of clinical domains (e.g., anxiety, depression, anger, physical pain) simultaneously without requiring the patient to carry out homework assignments or discuss the details of the event. The treatment of phantom limb pain and other somatic presentations is also reviewed. The ability of EMDR to achieve positive effects without homework indicates that it can be effectively employed on consecutive days, making it especially useful during combat situations.

  11. MicroRNA association with synucleinopathy conversion in rapid eye movement behavior disorder.

    Science.gov (United States)

    Fernández-Santiago, Rubén; Iranzo, Alex; Gaig, Carles; Serradell, Mónica; Fernández, Manel; Tolosa, Eduardo; Santamaría, Joan; Ezquerra, Mario

    2015-05-01

    Recently, we reported downregulated circulating levels of the microRNAs miR-19b, miR-29a, and miR-29c in Parkinson disease. Here we investigated the expression of these microRNAs in serum samples from 56 patients with idiopathic rapid eye movement sleep behavior disorder, before and after their conversion into a synucleinopathy. Compared to controls, we found that the expression level of miR-19b is downregulated in patients with idiopathic rapid eye movement sleep behavior disorder and antedates the diagnosis of Parkinson disease and dementia with Lewy bodies after 4.67 ± 2.61 years of follow-up. Our findings indicate that dysregulation of the microRNA miR-19b occurs in the prodromal stage of synucleinopathies. © 2015 American Neurological Association.

  12. Feature Selection in Classification of Eye Movements Using Electrooculography for Activity Recognition

    Directory of Open Access Journals (Sweden)

    S. Mala

    2014-01-01

    Full Text Available Activity recognition is needed in different requisition, for example, reconnaissance system, patient monitoring, and human-computer interfaces. Feature selection plays an important role in activity recognition, data mining, and machine learning. In selecting subset of features, an efficient evolutionary algorithm Differential Evolution (DE, a very efficient optimizer, is used for finding informative features from eye movements using electrooculography (EOG. Many researchers use EOG signals in human-computer interactions with various computational intelligence methods to analyze eye movements. The proposed system involves analysis of EOG signals using clearness based features, minimum redundancy maximum relevance features, and Differential Evolution based features. This work concentrates more on the feature selection algorithm based on DE in order to improve the classification for faultless activity recognition.

  13. Attention and choice: a review on eye movements in decision making.

    Science.gov (United States)

    Orquin, Jacob L; Mueller Loose, Simone

    2013-09-01

    This paper reviews studies on eye movements in decision making, and compares their observations to theoretical predictions concerning the role of attention in decision making. Four decision theories are examined: rational models, bounded rationality, evidence accumulation, and parallel constraint satisfaction models. Although most theories were confirmed with regard to certain predictions, none of the theories adequately accounted for the role of attention during decision making. Several observations emerged concerning the drivers and down-stream effects of attention on choice, suggesting that attention processes plays an active role in constructing decisions. So far, decision theories have largely ignored the constructive role of attention by assuming that it is entirely determined by heuristics, or that it consists of stochastic information sampling. The empirical observations reveal that these assumptions are implausible, and that more accurate assumptions could have been made based on prior attention and eye movement research. Future decision making research would benefit from greater integration with attention research.

  14. Handedness of children determines preferential facial and eye movements related to hemispheric specialization

    OpenAIRE

    Arteaga, Carmina; Poblano, Adrián

    2008-01-01

    BACKGROUND: Despite repeated demonstrations of asymmetries in several brain functions, the biological bases of such asymmetries have remained obscure. OBJECTIVE: To investigate development of lateralized facial and eye movements evoked by hemispheric stimulation in right-handed and left-handed children. METHOD: Fifty children were tested according to handedness by means of four tests: I. Mono-syllabic non-sense words, II. Tri-syllabic sense words, III. Visual field occlusion by black wall, an...

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

    OpenAIRE

    Horváth A; Papp A; Szűcs A

    2016-01-01

    András Horváth,1,2 Anikó Papp,1 Anna Szűcs,1 1Department of Neurology, National Institute of Clinical Neurosciences, 2János Szentágothai Doctoral School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary Abstract: 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 age...

  16. Apnea-Induced Rapid Eye Movement Sleep Disruption Impairs Human Spatial Navigational Memory

    OpenAIRE

    Varga, Andrew W.; Kishi, Akifumi; Mantua, Janna; Lim, Jason; Koushyk, Viachaslau; Leibert, David P.; Osorio, Ricardo S.; David M. Rapoport; Ayappa, Indu

    2014-01-01

    Hippocampal electrophysiology and behavioral evidence support a role for sleep in spatial navigational memory, but the role of particular sleep stages is less clear. Although rodent models suggest the importance of rapid eye movement (REM) sleep in spatial navigational memory, a similar role for REM sleep has never been examined in humans. We recruited subjects with severe obstructive sleep apnea (OSA) who were well treated and adherent with continuous positive airway pressure (CPAP). Restric...

  17. Developmental visual perception deficits with no indications of prosopagnosia in a child with abnormal eye movements.

    Science.gov (United States)

    Gilaie-Dotan, Sharon; Doron, Ravid

    2017-04-08

    Visual categories are associated with eccentricity biases in high-order visual cortex: Faces and reading with foveally-biased regions, while common objects and space with mid- and peripherally-biased regions. As face perception and reading are among the most challenging human visual skills, and are often regarded as the peak achievements of a distributed neural network supporting common objects perception, it is unclear why objects, which also rely on foveal vision to be processed, are associated with mid-peripheral rather than with a foveal bias. Here, we studied BN, a 9 y.o. boy who has normal basic-level vision, abnormal (limited) oculomotor pursuit and saccades, and shows developmental object and contour integration deficits but with no indication of prosopagnosia. Although we cannot infer causation from the data presented here, we suggest that normal pursuit and saccades could be critical for the development of contour integration and object perception. While faces and perhaps reading, when fixated upon, take up a small portion of central visual field and require only small eye movements to be properly processed, common objects typically prevail in mid-peripheral visual field and rely on longer-distance voluntary eye movements as saccades to be brought to fixation. While retinal information feeds into early visual cortex in an eccentricity orderly manner, we hypothesize that propagation of non-foveal information to mid and high-order visual cortex critically relies on circuitry involving eye movements. Limited or atypical eye movements, as in the case of BN, may hinder normal information flow to mid-eccentricity biased high-order visual cortex, adversely affecting its development and consequently inducing visual perceptual deficits predominantly for categories associated with these regions.

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

    OpenAIRE

    Coubard, Olivier A.

    2016-01-01

    Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, 26 years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in post-traumatic stress disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the reasons ...

  19. An integrative model for the neural mechanism of Eye Movement Desensitization and Reprocessing (EMDR)

    OpenAIRE

    Coubard, Olivier A.

    2016-01-01

    Since the seminal report by Shapiro that bilateral stimulation induces cognitive and emotional changes, twenty-six years of basic and clinical research have examined the effects of Eye Movement Desensitization and Reprocessing (EMDR) in anxiety disorders, particularly in Post-Traumatic Stress Disorder (PTSD). The present article aims at better understanding EMDR neural mechanism. I first review procedural aspects of EMDR protocol and theoretical hypothesis about EMDR effects, and develop the ...

  20. Combining top-down processes to guide eye movements during real-world scene search.

    Science.gov (United States)

    Malcolm, George L; Henderson, John M

    2010-02-10

    Eye movements can be guided by various types of information in real-world scenes. Here we investigated how the visual system combines multiple types of top-down information to facilitate search. We manipulated independently the specificity of the search target template and the usefulness of contextual constraint in an object search task. An eye tracker was used to segment search time into three behaviorally defined epochs so that influences on specific search processes could be identified. The results support previous studies indicating that the availability of either a specific target template or scene context facilitates search. The results also show that target template and contextual constraints combine additively in facilitating search. The results extend recent eye guidance models by suggesting the manner in which our visual system utilizes multiple types of top-down information.