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Annual Review of Vision Science Sep 2023As we navigate and behave in the world, we are constantly deciding, a few times per second, where to look next. The outcomes of these decisions in response to visual... (Review)
Review
As we navigate and behave in the world, we are constantly deciding, a few times per second, where to look next. The outcomes of these decisions in response to visual input are comparatively easy to measure as trajectories of eye movements, offering insight into many unconscious and conscious visual and cognitive processes. In this article, we review recent advances in predicting where we look. We focus on evaluating and comparing models: How can we consistently measure how well models predict eye movements, and how can we judge the contribution of different mechanisms? Probabilistic models facilitate a unified approach to fixation prediction that allows us to use explainable information explained to compare different models across different settings, such as static and video saliency, as well as scanpath prediction. We review how the large variety of saliency maps and scanpath models can be translated into this unifying framework, how much different factors contribute, and how we can select the most informative examples for model comparison. We conclude that the universal scale of information gain offers a powerful tool for the inspection of candidate mechanisms and experimental design that helps us understand the continual decision-making process that determines where we look.
Topics: Fixation, Ocular; Eye Movements
PubMed: 37419107
DOI: 10.1146/annurev-vision-120822-072528 -
Practical Neurology Oct 2018Ocular neuromyotonia is a rare, albeit treatable, ocular motor disorder, characterised by recurrent brief episodes of diplopia due to tonic extraocular muscle...
Ocular neuromyotonia is a rare, albeit treatable, ocular motor disorder, characterised by recurrent brief episodes of diplopia due to tonic extraocular muscle contraction. Ephaptic transmission in a chronically damaged ocular motor nerve is the possible underlying mechanism. It usually improves with carbamazepine. A 53-year-old woman presented with a 4-month history of recurrent episodes of binocular vertical diplopia (up to 40/day), either spontaneously or after sustained downward gaze. Between episodes she had a mild left fourth nerve palsy. Sustained downward gaze consistently triggered downward left eye tonic deviation, lasting around 1 min. MR scan of the brain was normal. She improved on starting carbamazepine but developed a rash that necessitated stopping the drug. Switching to lacosamide controlled her symptoms.
Topics: Female; Fixation, Ocular; Humans; Isaacs Syndrome; Middle Aged; Ocular Motility Disorders
PubMed: 29467180
DOI: 10.1136/practneurol-2017-001866 -
Frontiers in Bioscience (Scholar... Jan 2018Microperimetric biofeedback training (MBFT) is a visual rehabilitative strategy based on fixation stability improvement reinforcing or creating a new preferential... (Review)
Review
Microperimetric biofeedback training (MBFT) is a visual rehabilitative strategy based on fixation stability improvement reinforcing or creating a new preferential fixation locus. The rationale consists in reeducating visual system to a new visual condition, promoting retina-brain transmission, and thus cortical plasticity. The use of MBFT found is major application in visual diseases involving central vision, but later it revealed promising functional outcomes even in myopia, inherited retinal degenerations and nystagmus. However, the use of microperimetric biofeedback is still limited due to poor knowledge of the procedure and inconsistent standards of practice, and thus an incipient skepticism on its efficacy. This review provides an overview of the rationale, current implications, procedures and future perspectives of microperimetric biofeedback training.
Topics: Biofeedback, Psychology; Fixation, Ocular; Humans; Retina; Vision, Low
PubMed: 28930518
DOI: 10.2741/s500 -
Journal of Physiological Anthropology Sep 2020Saccadic eye movements can allude to emotional states and visual attention. Recent studies have shown that microsaccadic responses (i.e., small fixational eye movements)... (Review)
Review
Saccadic eye movements can allude to emotional states and visual attention. Recent studies have shown that microsaccadic responses (i.e., small fixational eye movements) reflect advanced brain activity during attentional and cognitive tasks. Moreover, the microsaccadic activity related to emotional attention provides new insights into this field. For example, emotional pictures attenuate the microsaccadic rate, and microsaccadic responses to covert attention occur in the direction opposite to a negative emotional target. However, the effects of various emotional events on microsaccadic activity remain debatable. This review introduces visual attention and eye movement studies that support findings on the modulation of microsaccadic responses to emotional events, comparing them with typical microsaccadic responses. This review also discusses the brain neuronal mechanisms governing microsaccadic responses to the attentional shifts triggered by emotion-related stimuli. It is hard to reveal the direct brain pathway of the microsaccadic modulation, especially in advanced (e.g., sustained anger, envy, distrust, guilt, frustration, delight, attraction, trust, and love), but also in basic human emotions (i.e., anger, disgust, fear, happiness, sadness, and surprise). However, non-human primates and human studies can uncover the possible brain pathways of emotional attention and microsaccades, thus providing future research directions. In particular, the facilitated (or reduced) attention is common evidence that microsaccadic activities change under a variety of social modalities (e.g., cognition, music, mental illness, and working memory) that elicit emotions and feelings.
Topics: Attention; Brain; Emotions; Fear; Fixation, Ocular; Humans; Mental Disorders; Saccades
PubMed: 32887665
DOI: 10.1186/s40101-020-00238-6 -
Philosophical Transactions of the Royal... Apr 2017Scientists have pondered the perceptual effects of ocular motion, and those of its counterpart, ocular stillness, for over 200 years. The unremitting 'trembling of the... (Review)
Review
Scientists have pondered the perceptual effects of ocular motion, and those of its counterpart, ocular stillness, for over 200 years. The unremitting 'trembling of the eye' that occurs even during gaze fixation was first noted by Jurin in 1738. In 1794, Erasmus Darwin documented that gaze fixation produces perceptual fading, a phenomenon rediscovered in 1804 by Ignaz Paul Vital Troxler. Studies in the twentieth century established that Jurin's 'eye trembling' consisted of three main types of 'fixational' eye movements, now called microsaccades (or fixational saccades), drifts and tremor. Yet, owing to the constant and minute nature of these motions, the study of their perceptual and physiological consequences has met significant technological challenges. Studies starting in the 1950s and continuing in the present have attempted to study vision during retinal stabilization-a technique that consists on shifting any and all visual stimuli presented to the eye in such a way as to nullify all concurrent eye movements-providing a tantalizing glimpse of vision in the absence of change. No research to date has achieved perfect retinal stabilization, however, and so other work has devised substitute ways to counteract eye motion, such as by studying the perception of afterimages or of the entoptic images formed by retinal vessels, which are completely stable with respect to the eye. Yet other research has taken the alternative tack to control eye motion by behavioural instruction to fix one's gaze or to keep one's gaze still, during concurrent physiological and/or psychophysical measurements. Here, we review the existing data-from historical and contemporary studies that have aimed to nullify or minimize eye motion-on the perceptual and physiological consequences of perfect versus imperfect fixation. We also discuss the accuracy, quality and stability of ocular fixation, and the bottom-up and top-down influences that affect fixation behaviour.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'.
Topics: Fixation, Ocular; Humans; Retina; Saccades; Vision, Ocular
PubMed: 28242737
DOI: 10.1098/rstb.2016.0204 -
ELife Mar 2022Eye movements are neither necessary nor sufficient to account for the neural effects associated with covert attention.
Eye movements are neither necessary nor sufficient to account for the neural effects associated with covert attention.
Topics: Biomarkers; Eye Movements; Fixation, Ocular; Saccades; Visual Perception
PubMed: 35289270
DOI: 10.7554/eLife.77544 -
Sensors (Basel, Switzerland) Nov 2019The prevalence of autism spectrum disorders (ASD) has increased strongly over the past decades, and so has the demand for adequate behavioral assessment and support for... (Review)
Review
The prevalence of autism spectrum disorders (ASD) has increased strongly over the past decades, and so has the demand for adequate behavioral assessment and support for persons affected by ASD. Here we provide a review on original research that used sensor technology for an objective assessment of social behavior, either with the aim to assist the assessment of autism or with the aim to use this technology for intervention and support of people with autism. Considering rapid technological progress, we focus (1) on studies published within the last 10 years (2009-2019), (2) on contact- and irritation-free sensor technology that does not constrain natural movement and interaction, and (3) on sensory input from the face, the voice, or body movements. We conclude that sensor technology has already demonstrated its great potential for improving both behavioral assessment and interventions in autism spectrum disorders. We also discuss selected examples for recent theoretical questions related to the understanding of psychological changes and potentials in autism. In addition to its applied potential, we argue that sensor technology-when implemented by appropriate interdisciplinary teams-may even contribute to such theoretical issues in understanding autism.
Topics: Autism Spectrum Disorder; Cognition; Electronic Data Processing; Fixation, Ocular; Humans; Social Behavior; Voice
PubMed: 31689906
DOI: 10.3390/s19214787 -
Attention, Perception & Psychophysics May 2024Competing theories attempt to explain what guides eye movements when exploring natural scenes: bottom-up image salience and top-down semantic salience. In one study, we...
Competing theories attempt to explain what guides eye movements when exploring natural scenes: bottom-up image salience and top-down semantic salience. In one study, we apply language-based analyses to quantify the well-known observation that task influences gaze in natural scenes. Subjects viewed ten scenes as if they were performing one of two tasks. We found that the semantic similarity between the task and the labels of objects in the scenes captured the task-dependence of gaze (t(39) = 13.083; p < 0.001). In another study, we examined whether image salience or semantic salience better predicts gaze during a search task, and if viewing strategies are affected by searching for targets of high or low semantic relevance to the scene. Subjects searched 100 scenes for a high- or low-relevance object. We found that image salience becomes a worse predictor of gaze across successive fixations, while semantic salience remains a consistent predictor (X(1, N=40) = 75.148, p < .001). Furthermore, we found that semantic salience decreased as object relevance decreased (t(39) = 2.304; p = .027). These results suggest that semantic salience is a useful predictor of gaze during task-related scene viewing, and that even in target-absent trials, gaze is modulated by the relevance of a search target to the scene in which it might be located.
Topics: Humans; Semantics; Fixation, Ocular; Attention; Male; Female; Young Adult; Adult; Pattern Recognition, Visual; Eye Movements
PubMed: 38594445
DOI: 10.3758/s13414-024-02883-w -
Annual Review of Vision Science Nov 2015Humans 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... (Review)
Review
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.
Topics: Eye Movement Measurements; Eye Movements; Fixation, Ocular; Humans; Models, Neurological; Photic Stimulation; Retina; Saccades; Vision, Ocular; Visual Perception
PubMed: 27795997
DOI: 10.1146/annurev-vision-082114-035742 -
European Journal of Sport Science Feb 2017Scientists who have examined the gaze strategies employed by athletes have determined that longer quiet eye (QE) durations (QED) are characteristic of skilled compared... (Review)
Review
Scientists who have examined the gaze strategies employed by athletes have determined that longer quiet eye (QE) durations (QED) are characteristic of skilled compared to less-skilled performers. However, the cognitive mechanisms of the QE and, specifically, how the QED affects performance are not yet fully understood. We review research that has examined the functional mechanism underlying QE and discuss the neural networks that may be involved. We also highlight the limitations surrounding QE measurement and its definition and propose future research directions to address these shortcomings. Investigations into the behavioural and neural mechanisms of QE will aid the understanding of the perceptual and cognitive processes underlying expert performance and the factors that change as expertise develops.
Topics: Athletic Performance; Attention; Fixation, Ocular; Humans; Psychomotor Performance; Visual Perception
PubMed: 26356536
DOI: 10.1080/17461391.2015.1075595