Eye Movement Patterns Research Articles

Oculomotor Abnormalities during Reading in the Offspring of Late-Onset Alzheimer's Disease.

Eye movement patterns during reading are well defined and documented. Each eye movement ends up in a fixation point, which allows the brain to process the incoming information and program the following saccade. In this work, we investigated whether eye movement alterations during a reading task might be already present in middle-aged, cognitively normal offspring of late-onset Alzheimer's disease (O-LOAD). 18 O-LOAD and 18 age-matched healthy individuals with no family history of LOAD participated in the study. Participants were seated in front of a 20-inch LCD monitor, and single sentences were presented on it. Eye movements were recorded with an eye tracker with a sampling rate of 1000 Hz. Analysis of eye movements during reading revealed that O-LOAD displayed more fixations, shorter saccades, and shorter fixation durations than controls. The present study shows that O-LOAD experienced alterations in their eye movements during reading. O-LOAD eye movement behavior could be considered an initial sign of oculomotor impairment. Hence, the evaluation of eye movement during reading might be a useful tool for monitoring well-defined cognitive resources.

What are the characteristics of good Chinese second language readers? Evidence from eye movements

This study investigated the characteristics of good Chinese second language readers by observing their eye-movement patterns in reading articles manipulated to highlight different linguistic features. Participants’ linguistic resources were included as covariant variables. Results showed that good readers should be defined as both accurate and fast readers, although the two traits did not correlate with each other. Accurate reading was predicted by good orthographic knowledge, while fast reading was predicted by good lexical knowledge. Longer sentences did not show a significant impact on readers’ performance, which might imply that higher-level processes did not contribute as much as lower-level processes to the construction of good reading capabilities. All results were validated, while text readability was checked across different reading materials. Both reading universals and writing system specific features were found to be effective in explaining Chinese as a second language (CSL) reading processes. The research findings also informed the instruction of CSL reading, as Chinese is a very challenging logographic text.

Eye movement patterns correlate with overt emotional behaviours in rapid eye movement sleep

Growing evidence suggests that sleep plays a key role in regulating emotions. Rapid eye movements (REMs) in REM sleep could be associated with dreams emotions, but supporting evidence is indirect. To highlight this association, we studied the REM sleep during video-polysomnography of 20 subjects with REM sleep behaviour disorder (RBD), a model of enacted dreams offering direct access to the emotional content of the sleeper (face expression, speeches, behaviour). Video and the electro-oculography recordings were divided into 3 s time intervals and classified as non-behavioural, or behavioural (neutral, positive or negative emotions), and as containing no eye movements (EMs), slow eye movements (SEMs) or REMs (isolated or bursts). Compared to the absence of EMs, neutral behaviours successively increased in the presence of SEMs (odd ratio, OR = 1.4), then isolated REMs (OR = 2.8) and then REM bursts (OR = 4.6). Positive behaviours increased with SEMs (OR = 2.8) but did not increase further with isolated REMs (OR = 2.8) and REM bursts (OR = 3). Negative behaviours were absent with SEMs, increased with isolated REMs (OR = 2.6) and further with REM bursts (OR = 10.1). These results support an association between REMs and SEMs, and dream emotions.

Explicit and implicit mentalization of patients with first-episode schizophrenia: a study of self-referential gaze perception with eye movement analysis using hidden Markov models.

Mentalizing impairment is one of the core features of schizophrenia, and bias judgement of others' gaze as self-directing is common to schizophrenia patients. In this case-control study, 30 patients with first-episode schizophrenia (FES) and 30 matched healthy controls were assigned gaze perception tasks with variable stimulus presentation times (300ms and no time limit) to determine the presence of self-referential gaze perception (SRGP) bias. The eye movement pattern during the task were tracked and data were analysed using hidden Markov models (HMMs). The SRGP involves reporting of others' gaze intent and was used as a measurement of explicit mentalizing process. Eye movement measurement represents automated visual attention pattern and was considered as a measurement of implicit mentalizing process. The patients with FES had significantly more SRGP bias than the controls in the 300ms condition but not in the no-time-limit condition. Social cognitive function was related to SRGP bias in the patient group. Two distinct eye movement patterns were identified: eye-focused and nose-focused. Significant group differences in eye movement patterns in the 300ms condition were found with more controls had eye-focused pattern. Social anxiety symptoms were related to the nose-focused pattern, positive psychotic symptoms were related to the eye-focused pattern, and depressive symptoms were related to less consistent eye movement patterns. No significant relationship was found between SRGP bias and eye movement patterns. The dissociation between explicit and implicit mentalizing processes with different cognitive and symptom dimensions associated with the two processes suggests the presence of different mechanisms.

Computation of subjective value does not always elicit alternative‐based information searching in intertemporal choice

AbstractThe “subjective value” computation assumption holds that intertemporal choice is performed by computing subjective value by eliciting information searching within alternatives. Although widely accepted, this assumption has not been well tested. In the current eye tracking study, we developed a new paradigm using forward inference to examine this hypothesis. Participants were instructed to finish two types of intertemporal choice tasks. The free task resembled a standard task, in which participants were free to follow their own preference. The instructed task, on the other hand, provided a baseline whereby participants were given explicit instructions to calculate the subjective value of options according to a classic discounting model. The results of behavioral, fixation and scanpath demonstrated that participants performed the instructed task in a manner that was consistent with a discounting computation process. However, by comparing performances across the two tasks, we found that participants made more attribute‐based saccades when they made instructed choices, compared to when they made free choices. These findings provide no support for the “subjective value” assumption in intertemporal choice. That is, that the computation of subjective value is associated with alternative‐based information searching, further demonstrating the effectiveness of the forward inference paradigm in testing intertemporal choices models. This study also highlights the need for careful reexamination of the assumed relationship between eye movement patterns and corresponding underlying cognitive processes in intertemporal choice.

Eye Movement Patterns Can Distinguish Schizophrenia From the Major Affective Disorders and Healthy Control Subjects.

Background and hypothesisNo objective tests are currently available to help diagnosis of major psychiatric disorders. This study evaluates the potential of eye movement behavior patterns to predict schizophrenia subjects compared to those with major affective disorders and control groups.Study designEye movements were recorded from a training set of UK subjects with schizophrenia (SCZ; n = 120), bipolar affective disorder (BPAD; n = 141), major depressive disorder (MDD; n = 136), and healthy controls (CON; n = 142), and from a hold-out set of 133 individuals with proportional group sizes. A German cohort of SCZ (n = 60) and a Scottish cohort of CON subjects (n = 184) acted as a second semi-independent test set. All patients met DSMIV and ICD10 criteria for SCZ, BPAD, and MDD. Data from 98 eye movement features were extracted. We employed a gradient boosted (GB) decision tree multiclass classifier to develop a predictive model. We calculated the area under the curve (AUC) as the primary performance metric.Study resultsEstimates of AUC in one-versus-all comparisons were: SCZ (0.85), BPAD (0.78), MDD (0.76), and CON (0.85). Estimates on part-external validation were SCZ (0.89) and CON (0.65). In all cases, there was good specificity but only moderate sensitivity. The best individual discriminators included free viewing, fixation duration, and smooth pursuit tasks. The findings appear robust to potential confounders such as age, sex, medication, or mental state at the time of testing.ConclusionsEye movement patterns can discriminate schizophrenia from major mood disorders and control subjects with around 80% predictive accuracy.

Memory-driven eye movements prospectively predict dementia in people at risk of Alzheimer's disease.

Oculomotor behaviors linked to cognitive performance revealed neurocognitive features of Alzheimer's disease (AD) that can enhance the accuracy of its assessment and diagnosis. A sample of 107 participants (i.e., 65 mild cognitive impairment [MCI] and 42 controls) were recruited and followed up for 40 months. At baseline, they underwent assessment with the ViewMind digital biomarker, which draws cognitive-related patterns of eye movement while people perform the visual short-term memory binding task. Baseline data predicted that 36 patients with MCI would progress to the AD clinical syndrome (ADS Progressing). The remaining 29 MCI patients were predicted to remain as MCI or progress to other forms of dementia. After 40 months of follow-up, 94% of ADS Progressing patients had received a diagnosis of dementia, whereas none of the non-ADS Progressing had. The analysis of eye movement behavior combined with cognitive markers for AD can effectively predict progression to ADS among patients with MCI.

Relations between Visual Axis and Upper Extremity Motion during Eating in Healthy People: Correspondence of Eye Movement Pattern and Velocity Curve

Relations between Visual Axis and Upper Extremity Motion during Eating in Healthy People: Correspondence of Eye Movement Pattern and Velocity Curve

A Preparatory Study on the Difference in Eye Movement Patterns of Beginner Level Japanese EFL Learners and their Intermediate Counterparts

A Preparatory Study on the Difference in Eye Movement Patterns of Beginner Level Japanese EFL Learners and their Intermediate Counterparts

Evidence from ERP and Eye Movements as Markers of Language Dysfunction in Dyslexia

Developmental dyslexia is a complex reading disorder involving genetic and environmental factors. After more than a century of research, its etiology remains debated. Two hypotheses are often put forward by scholars to account for the causes of dyslexia. The most common one, the linguistic hypothesis, postulates that dyslexia is due to poor phonological awareness. The alternative hypothesis considers that dyslexia is caused by visual-attentional deficits and abnormal eye movement patterns. This article reviews a series of selected event-related brain potential (ERP) and eye movement studies on the reading ability of dyslexic individuals to provide an informed state of knowledge on the etiology of dyslexia. Our purpose is to show that the two abovementioned hypotheses are not necessarily mutually exclusive, and that dyslexia should rather be considered as a multifactorial deficit.

Eye Movement Patterns Reflecting Cybersickness: Evidence from Different Experience Modes of a Virtual Reality Game.

This study investigated whether the degree of cybersickness varies depending on different virtual reality experience modes (playing vs. watching) and whether specific eye movement parameters reflect changes in cybersickness. Simulator Sickness Questionnaire results from 20 participants (10 playing and 10 watching) showed that cybersickness was much more severe in the watching mode, particularly during the second of the three total trials. Moreover, cybersickness' changing pattern was reflected in the center gaze ratio and scan-path length. These findings imply the importance of physiological measurements for a deeper understanding of cybersickness in theoretical and practical respects.

Eye-tracking as a proxy for coherence and complexity of texts.

Reading is a complex cognitive process that involves primary oculomotor function and high-level activities like attention focus and language processing. When we read, our eyes move by primary physiological functions while responding to language-processing demands. In fact, the eyes perform discontinuous twofold movements, namely, successive long jumps (saccades) interposed by small steps (fixations) in which the gaze “scans” confined locations. It is only through the fixations that information is effectively captured for brain processing. Since individuals can express similar as well as entirely different opinions about a given text, it is therefore expected that the form, content and style of a text could induce different eye-movement patterns among people. A question that naturally arises is whether these individuals’ behaviours are correlated, so that eye-tracking while reading can be used as a proxy for text subjective properties. Here we perform a set of eye-tracking experiments with a group of individuals reading different types of texts, including children stories, random word generated texts and excerpts from literature work. In parallel, an extensive Internet survey was conducted for categorizing these texts in terms of their complexity and coherence, considering a large number of individuals selected according to different ages, gender and levels of education. The computational analysis of the fixation maps obtained from the gaze trajectories of the subjects for a given text reveals that the average “magnetization” of the fixation configurations correlates strongly with their complexity observed in the survey. Moreover, we perform a thermodynamic analysis using the Maximum-Entropy Model and find that coherent texts were closer to their corresponding “critical points” than non-coherent ones, as computed from the Pairwise Maximum-Entropy method, suggesting that different texts may induce distinct cohesive reading activities.

Eye movement patterns differ while watching captioned videos of second language vs. mathematics lessons

BackgroundExtant eye-tracking studies suggest that foreign-language learners tend to read the native language captions while watching foreign-language videos. However, it remains unclear how the captions affect the learners' eye movements when watching Math videos. PurposeWhile watching teaching videos, we seek to determine how the lesson type (English or Math), cognitive load (high or low), and caption type (meaningful, no captions, or meaningless) affect the dwell times and fixation counts on the captions. MethodsOne hundred and eighty undergraduate students were randomly and equally assigned to six (2 lesson type × 3 caption type) conditions. Each participant watched two short teaching videos (one low load and one high load). After watching each video, a comprehension test and three self-reported items (fatigue, effort, and difficulty) regarding this particular video were given. ResultsWe reported more dwell times and fixation counts on the meaningful captions, compared to the meaningless captions and no captions. In the high-load condition, viewers watching an English lesson relied more on the meaningful captions than they did when watching a Math lesson. In the low-load condition, the dwell times and fixation counts on the captions were similar between the English and Math lessons. Finally, the captions did not affect the comprehension test performances after ruling out individual differences in the prior performances of English and Math. ConclusionsEnglish language learning may rely more on the captions than is the case in learning Math. This study provides the direction for designing multimedia teaching materials in the current trend of multimedia teaching.

Encoding of facial features by single neurons in the human amygdala and hippocampus

Faces are salient social stimuli that attract a stereotypical pattern of eye movement. The human amygdala and hippocampus are involved in various aspects of face processing; however, it remains unclear how they encode the content of fixations when viewing faces. To answer this question, we employed single-neuron recordings with simultaneous eye tracking when participants viewed natural face stimuli. We found a class of neurons in the human amygdala and hippocampus that encoded salient facial features such as the eyes and mouth. With a control experiment using non-face stimuli, we further showed that feature selectivity was specific to faces. We also found another population of neurons that differentiated saccades to the eyes vs. the mouth. Population decoding confirmed our results and further revealed the temporal dynamics of face feature coding. Interestingly, we found that the amygdala and hippocampus played different roles in encoding facial features. Lastly, we revealed two functional roles of feature-selective neurons: 1) they encoded the salient region for face recognition, and 2) they were related to perceived social trait judgments. Together, our results link eye movement with neural face processing and provide important mechanistic insights for human face perception.

When Eyes Wander Around: Mind-Wandering as Revealed by Eye Movement Analysis with Hidden Markov Models.

Mind-wandering has been shown to largely influence our learning efficiency, especially in the digital and distracting era nowadays. Detecting mind-wandering thus becomes imperative in educational scenarios. Here, we used a wearable eye-tracker to record eye movements during the sustained attention to response task. Eye movement analysis with hidden Markov models (EMHMM), which takes both spatial and temporal eye-movement information into account, was used to examine if participants’ eye movement patterns can differentiate between the states of focused attention and mind-wandering. Two representative eye movement patterns were discovered through clustering using EMHMM: centralized and distributed patterns. Results showed that participants with the centralized pattern had better performance on detecting targets and rated themselves as more focused than those with the distributed pattern. This study indicates that distinct eye movement patterns are associated with different attentional states (focused attention vs. mind-wandering) and demonstrates a novel approach in using EMHMM to study attention. Moreover, this study provides a potential approach to capture the mind-wandering state in the classroom without interrupting the ongoing learning behavior.

EyeSay: Make Eyes Speak for ALS Patients with Deep Transfer Learning-empowered Wearable.

Eye dynamics, a typical expression of brain activities, is an emerging modality for emerging and promising smart health applications. Electrooculogram (EOG) - a natural bio-electric signal generated during eye movements, if decoded, is of great potential to reveal the user's mind and enable voice-free communication for patients with amyotrophic lateral sclerosis (ALS). ALS patients usually lose physical movement abilities including speech and handwriting but fortunately can move their eyes. In this study, we propose a novel deep transfer learning-empowered system, called "eyeSay", which leverages both deep learning and transfer learning for intelligent eye EOG-to-speech translation. More specifically, we have designed a multi-stage convolutional neural network (CNN) to analyze the eye-written words, named as CNN-word. Moreover, to reveal fundamental patterns of eye movements, we build a transferable feature extractor, CNN-stroke, upon eye strokes that are building components of an eye word. Then, we transfer the CNN-stroke model to the eye word learning task in an innovative way, that is, use CNN-stroke as an additional branch of CNN-word to generate a stroke probability map. The achieved boostCNN-word model, enhanced by the transferable feature extractor, has greatly improved the eye word decoding performance. This novel study will directly contribute to voice-free communications for ALS patients, and greatly advance the ubiquitous eye EOG-based smart health area.

Eye movement pattern of attention bias to emotional stimuli in women with high premenstrual symptoms

Background and objectivesPremenstrual Syndrome (PMS) refers to a group of symptoms linked to the menstrual cycle. Women with PMS have cognitive mode of rumination, which leads to their attention bias to emotional stimuli. This study investigated the biases for emotional information in women with high premenstrual symptoms (HPMS) compared with women with low premenstrual symptoms (LPMS). MethodsA total of 38 women with HPMS and 44 women with LPMS completed self-report questionnaires and a free viewing task with eye-tracking technology. ResultsThe questionnaire results indicate that women in the HPMS group had higher levels of rumination than those in the LPMS group. The eye-tracking results show that women in the HPMS group had an orientation bias towards negative emotional stimuli in the early cognitive process. In the late cognitive process, women in the HPMS group had accelerated attentional disengagement to positive emotional stimuli and difficult attentional disengagement to negative emotional stimuli. Further correlation analysis revealed positive relationships between the scores of initial fixation latency bias of positive pictures in premenstrual phase and the scores of symptom rumination in both groups and between the scores of initial fixation latency bias of positive pictures in premenstrual phase and the scores of brooding in HPMS group. LimitationsThis study used a retrospective questionnaire to assess the symptoms of PMS. ConclusionsWomen with HPMS had impaired attentional engagement and disengagement to emotional stimuli compared with women with LPMS, and it may be related to their cognitive mode of rumination.

Eye Movements during Dynamic Scene Viewing are Affected by Visual Attention Skills and Events of the Scene: Evidence from First-Person Shooter Gameplay Videos.

The role of individual differences during dynamic scene viewing was explored. Participants (N=38) watched a gameplay video of a first-person shooter (FPS) videogame while their eye movements were recorded. In addition, the participants’ skills in three visual attention tasks (attentional blink, visual search, and multiple object tracking) were assessed. The results showed that individual differences in visual attention tasks were associated with eye movement patterns observed during viewing of the gameplay video. The differences were noted in four eye movement measures: number of fixations, fixation durations, saccade amplitudes and fixation distances from the center of the screen. The individual differences showed during specific events of the video as well as during the video as a whole. The results highlight that an unedited, fast-paced and cluttered dynamic scene can bring about individual differences in dynamic scene viewing.

Identifying map users with eye movement data from map-based spatial tasks: user privacy concerns

ABSTRACT Individuals with different characteristics exhibit different eye movement patterns in map reading and wayfinding tasks. In this study, we aim to explore whether and to what extent map users’ eye movements can be used to detect who created them. Specifically, we focus on the use of gaze data for inferring users’ identities when users are performing map-based spatial tasks. We collected 32 participants’ eye movement data as they utilized maps to complete a series of self-localization and spatial orientation tasks. We extracted five sets of eye movement features and trained a random forest classifier. We used a leave-one-task-out approach to cross-validate the classifier and achieved the best identification rate of 89%, with a 2.7% equal error rate. This result is among the best performances reported in eye movement user identification studies. We evaluated the feature importance and found that basic statistical features (e.g. pupil size, saccade latency and fixation dispersion) yielded better performance than other feature sets (e.g. spatial fixation densities, saccade directions and saccade encodings). The results open the potential to develop personalized and adaptive gaze-based map interactions but also raise concerns about user privacy protection in data sharing and gaze-based geoapplications.

Data-driven group comparisons of eye fixations to dynamic stimuli.

Recent advances in software and hardware have allowed eye tracking to move away from static images to more ecologically relevant video streams. The analysis of eye tracking data for such dynamic stimuli, however, is not without challenges. The frame-by-frame coding of regions of interest (ROIs) is labour-intensive and computer vision techniques to automatically code such ROIs are not yet mainstream, restricting the use of such stimuli. Combined with the more general problem of defining relevant ROIs for video frames, methods are needed that facilitate data analysis. Here, we present a first evaluation of an easy-to-implement data-driven method with the potential to address these issues. To test the new method, we examined the differences in eye movements of self-reported politically left- or right-wing leaning participants to video clips of left- and right-wing politicians. The results show that our method can accurately predict group membership on the basis of eye movement patterns, isolate video clips that best distinguish people on the political left–right spectrum, and reveal the section of each video clip with the largest group differences. Our methodology thereby aids the understanding of group differences in gaze behaviour, and the identification of critical stimuli for follow-up studies or for use in saccade diagnosis.