1
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Wang Z, Meghanathan RN, Pollmann S, Wang L. Common structure of saccades and microsaccades in visual perception. J Vis 2024; 24:20. [PMID: 38656530 PMCID: PMC11044844 DOI: 10.1167/jov.24.4.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 02/24/2024] [Indexed: 04/26/2024] Open
Abstract
We obtain large amounts of external information through our eyes, a process often considered analogous to picture mapping onto a camera lens. However, our eyes are never as still as a camera lens, with saccades occurring between fixations and microsaccades occurring within a fixation. Although saccades are agreed to be functional for information sampling in visual perception, it remains unknown if microsaccades have a similar function when eye movement is restricted. Here, we demonstrated that saccades and microsaccades share common spatiotemporal structures in viewing visual objects. Twenty-seven adults viewed faces and houses in free-viewing and fixation-controlled conditions. Both saccades and microsaccades showed distinctive spatiotemporal patterns between face and house viewing that could be discriminated by pattern classifications. The classifications based on saccades and microsaccades could also be mutually generalized. Importantly, individuals who showed more distinctive saccadic patterns between faces and houses also showed more distinctive microsaccadic patterns. Moreover, saccades and microsaccades showed a higher structure similarity for face viewing than house viewing and a common orienting preference for the eye region over the mouth region. These findings suggested a common oculomotor program that is used to optimize information sampling during visual object perception.
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Affiliation(s)
- Zhenni Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Institute of Psychology and Behavioral Science, Shanghai Jiao Tong University, Shanghai, China
| | | | - Stefan Pollmann
- Department of Experimental Psychology, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Lihui Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Institute of Psychology and Behavioral Science, Shanghai Jiao Tong University, Shanghai, China
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2
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Broda MD, de Haas B. Individual differences in human gaze behavior generalize from faces to objects. Proc Natl Acad Sci U S A 2024; 121:e2322149121. [PMID: 38470925 PMCID: PMC10963009 DOI: 10.1073/pnas.2322149121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 01/22/2024] [Indexed: 03/14/2024] Open
Abstract
Individuals differ in where they fixate on a face, with some looking closer to the eyes while others prefer the mouth region. These individual biases are highly robust, generalize from the lab to the outside world, and have been associated with social cognition and associated disorders. However, it is unclear, whether these biases are specific to faces or influenced by domain-general mechanisms of vision. Here, we juxtaposed these hypotheses by testing whether individual face fixation biases generalize to inanimate objects. We analyzed >1.8 million fixations toward faces and objects in complex natural scenes from 405 participants tested in multiple labs. Consistent interindividual differences in fixation positions were highly inter-correlated across faces and objects in all samples. Observers who fixated closer to the eye region also fixated higher on inanimate objects and vice versa. Furthermore, the inter-individual spread of fixation positions scaled with target size in precisely the same, non-linear manner for faces and objects. These findings contradict a purely domain-specific account of individual face gaze. Instead, they suggest significant domain-general contributions to the individual way we look at faces, a finding with potential relevance for basic vision, face perception, social cognition, and associated clinical conditions.
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Affiliation(s)
- Maximilian Davide Broda
- Experimental Psychology, Justus Liebig University Giessen, Giessen35394, Germany
- Center for Mind, Brain and Behavior, Universities of Marburg, Giessen, and Darmstadt, Marburg35032, Germany
| | - Benjamin de Haas
- Experimental Psychology, Justus Liebig University Giessen, Giessen35394, Germany
- Center for Mind, Brain and Behavior, Universities of Marburg, Giessen, and Darmstadt, Marburg35032, Germany
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3
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Guzhang Y, Shelchkova N, Clark AM, Poletti M. Ultra-fine resolution of pre-saccadic attention in the fovea. Curr Biol 2024; 34:147-155.e2. [PMID: 38154463 PMCID: PMC10842882 DOI: 10.1016/j.cub.2023.11.064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 10/13/2023] [Accepted: 11/29/2023] [Indexed: 12/30/2023]
Abstract
Microsaccades, the tiny gaze relocations that occurr during fixation, have been linked to covert attention deployed degrees away from the center of gaze. However, the link between attention and microsaccades is deeper in that it also unfolds at the foveal scale. Here, we have examined the spatial grain of pre-microsaccadic attention across the 1° foveola. Through the use of high-precision eye-tracking and gaze-contingent display system that achieves arcminute precision in gaze localization, we have shown that the spotlight of attention at this scale can reach a strikingly high resolution, in the order of 0.17°. Further, when a microsaccade occurs, vision is modulated in a peculiar way across the foveola; whereas fine spatial vision is enhanced at the microsaccade goal location, it drops at the very center of gaze, where acuity is normally highest. These results reveal the finesse of the visuomotor system and of the interplay between eye movements and attention.
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Affiliation(s)
- Yue Guzhang
- Department of Brain and Cognitive Sciences, University of Rochester, Meliora Hall, Rochester, NY 14627, USA
| | - Natalya Shelchkova
- Graduate Program in Computational Neuroscience, University of Chicago, 5812 S. Ellis Avenue, Chicago, IL 60637, USA
| | - Ashley M Clark
- Department of Brain and Cognitive Sciences, University of Rochester, Meliora Hall, Rochester, NY 14627, USA
| | - Martina Poletti
- Department of Brain and Cognitive Sciences, University of Rochester, Meliora Hall, Rochester, NY 14627, USA; Department of Neuroscience, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14627, USA; Center for Visual Science, University of Rochester, 361 Meliora Hall, Rochester, NY 14627, USA.
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4
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Poletti M. An eye for detail: Eye movements and attention at the foveal scale. Vision Res 2023; 211:108277. [PMID: 37379763 PMCID: PMC10528557 DOI: 10.1016/j.visres.2023.108277] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/08/2023] [Accepted: 06/08/2023] [Indexed: 06/30/2023]
Abstract
Human vision relies on a tiny region of the retina, the 1-deg foveola, to achieve high spatial resolution. Foveal vision is of paramount importance in daily activities, yet its study is challenging, as eye movements incessantly displace stimuli across this region. Here I will review work that, building on recent advances in eye-tracking and gaze-contingent display, examines how attention and eye movements operate at the foveal level. This research highlights how exploration of fine spatial detail unfolds following visuomotor strategies reminiscent of those occurring at larger scales. It shows that, together with highly precise control of attention, this motor activity is linked to non-homogenous processing within the foveola and selectively modulates sensitivity both in space and time. Overall, the picture emerges of a highly dynamic foveal perception in which fine spatial vision, rather than simply being the result of placing a stimulus at the center of gaze, is the result of a finely tuned and orchestrated synergy of motor, cognitive, and attentional processes.
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Affiliation(s)
- Martina Poletti
- Department of Brain and Cognitive Sciences, University of Rochester, United States; Center for Visual Science, University of Rochester, United States; Department of Neuroscience, University of Rochester, United States.
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5
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Willett SM, Mayo JP. Reply to van Ede: Pulling on the threads of microsaccades and attention: What's left? Proc Natl Acad Sci U S A 2023; 120:e2311468120. [PMID: 37603739 PMCID: PMC10466092 DOI: 10.1073/pnas.2311468120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023] Open
Affiliation(s)
- Shawn M. Willett
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA15213
| | - J. Patrick Mayo
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA15213
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA15260
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González-Vides L, Hernández-Verdejo JL, Cañadas-Suárez P. Eye Tracking in Optometry: A Systematic Review. J Eye Mov Res 2023; 16:10.16910/jemr.16.3.3. [PMID: 38111688 PMCID: PMC10725735 DOI: 10.16910/jemr.16.3.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023] Open
Abstract
This systematic review examines the use of eye-tracking devices in optometry, describing their main characteristics, areas of application and metrics used. Using the PRISMA method, a systematic search was performed of three databases. The search strategy identified 141 reports relevant to this topic, indicating the exponential growth over the past ten years of the use of eye trackers in optometry. Eye-tracking technology was applied in at least 12 areas of the field of optometry and rehabilitation, the main ones being optometric device technology, and the assessment, treatment, and analysis of ocular disorders. The main devices reported on were infrared light-based and had an image capture frequency of 60 Hz to 2000 Hz. The main metrics mentioned were fixations, saccadic movements, smooth pursuit, microsaccades, and pupil variables. Study quality was sometimes limited in that incomplete information was provided regarding the devices used, the study design, the methods used, participants' visual function and statistical treatment of data. While there is still a need for more research in this area, eye-tracking devices should be more actively incorporated as a useful tool with both clinical and research applications. This review highlights the robustness this technology offers to obtain objective information about a person's vision in terms of optometry and visual function, with implications for improving visual health services and our understanding of the vision process.
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7
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Willett SM, Mayo JP. Microsaccades are directed toward the midpoint between targets in a variably cued attention task. Proc Natl Acad Sci U S A 2023; 120:e2220552120. [PMID: 37155892 PMCID: PMC10194007 DOI: 10.1073/pnas.2220552120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 04/10/2023] [Indexed: 05/10/2023] Open
Abstract
Reliable, noninvasive biomarkers that reveal the internal state of a subject are an invaluable tool for neurological diagnoses. Small fixational eye movements, called microsaccades, are a candidate biomarker thought to reflect a subject's focus of attention [Z. M. Hafed, J. J. Clark, VisionRes. 42, 2533-2545 (2002); R. Engbert, R. Kliegl, VisionRes. 43, 1035-1045 (2003)]. The linkage between the direction of microsaccades and attention has mainly been demonstrated using explicit and unambiguous attentional cues. However, the natural world is seldom predictable and rarely provides unambiguous information. Thus, a useful biomarker must be robust to such changes in environmental statistics. To determine how well microsaccades reveal visual-spatial attention across behavioral contexts, we analyzed these fixational eye movements in monkeys performing a conventional change detection task. The task included two stimulus locations and variable cue validities across blocks of trials. Subjects were adept at the task, showing precise and graded modulations of visual attention for subtle target changes and performing better and faster when the cue was more reliable [J. P. Mayo, J. H. R. Maunsell, J. Neurosci. 36, 5353 (2016)]. However, over tens of thousands of microsaccades, we found no difference in microsaccade direction between cued locations when cue variability was high nor between hit and miss trials. Instead, microsaccades were made toward the midpoint of the two target locations, not toward individual targets. Our results suggest that the direction of microsaccades should be interpreted with caution and may not be a reliable measure of covert spatial attention in more complex viewing conditions.
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Affiliation(s)
- Shawn M. Willett
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, 15213 Pittsburgh, PA
| | - J. Patrick Mayo
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, 15213 Pittsburgh, PA
- Department of Bioengineering, University of Pittsburgh, 15260 Pittsburgh, PA
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Wu RJ, Clark AM, Cox MA, Intoy J, Jolly PC, Zhao Z, Rucci M. High-resolution eye-tracking via digital imaging of Purkinje reflections. J Vis 2023; 23:4. [PMID: 37140912 PMCID: PMC10166114 DOI: 10.1167/jov.23.5.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Reliably measuring eye movements and determining where the observer looks are fundamental needs in vision science. A classical approach to achieve high-resolution oculomotor measurements is the so-called dual Purkinje image (DPI) method, a technique that relies on the relative motion of the reflections generated by two distinct surfaces in the eye, the cornea and the back of the lens. This technique has been traditionally implemented in fragile and difficult to operate analog devices, which have remained exclusive use of specialized oculomotor laboratories. Here we describe progress on the development of a digital DPI, a system that builds on recent advances in digital imaging to enable fast, highly precise eye-tracking without the complications of previous analog devices. This system integrates an optical setup with no moving components with a digital imaging module and dedicated software on a fast processing unit. Data from both artificial and human eyes demonstrate subarcminute resolution at 1 kHz. Furthermore, when coupled with previously developed gaze-contingent calibration methods, this system enables localization of the line of sight within a few arcminutes.
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Affiliation(s)
- Ruei-Jr Wu
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Ashley M Clark
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele A Cox
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Janis Intoy
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Paul C Jolly
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Zhetuo Zhao
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
| | - Michele Rucci
- Department of Brain & Cognitive Sciences and Center for Visual Science, University of Rochester, 310 Meliora Hall, Rochester, NY, USA
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9
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Mei Chow H, Spering M. Eye movements during optic flow perception. Vision Res 2023; 204:108164. [PMID: 36566560 DOI: 10.1016/j.visres.2022.108164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/22/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022]
Abstract
Optic flow is an important visual cue for human perception and locomotion and naturally triggers eye movements. Here we investigate whether the perception of optic flow direction is limited or enhanced by eye movements. In Exp. 1, 23 human observers localized the focus of expansion (FOE) of an optic flow pattern; in Exp. 2, 18 observers had to detect brief visual changes at the FOE. Both tasks were completed during free viewing and fixation conditions while eye movements were recorded. Task difficulty was varied by manipulating the coherence of radial motion from the FOE (4 %-90 %). During free viewing, observers tracked the optic flow pattern with a combination of saccades and smooth eye movements. During fixation, observers nevertheless made small-scale eye movements. Despite differences in spatial scale, eye movements during free viewing and fixation were similarly directed toward the FOE (saccades) and away from the FOE (smooth tracking). Whereas FOE localization sensitivity was not affected by eye movement instructions (Exp. 1), observers' sensitivity to detect brief changes at the FOE was 27 % higher (p <.001) during free-viewing compared to fixation (Exp. 2). This performance benefit was linked to reduced saccade endpoint errors, indicating the direct beneficial impact of foveating eye movements on performance in a fine-grain perceptual task, but not during coarse perceptual localization.
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Affiliation(s)
- Hiu Mei Chow
- Dept. of Psychology, St. Thomas University, Fredericton, Canada; Dept. of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada.
| | - Miriam Spering
- Dept. of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, Canada; Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, Canada
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10
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Inferring visual space from ultra-fine extra-retinal knowledge of gaze position. Nat Commun 2023; 14:269. [PMID: 36650146 PMCID: PMC9845343 DOI: 10.1038/s41467-023-35834-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 01/03/2023] [Indexed: 01/18/2023] Open
Abstract
It has long been debated how humans resolve fine details and perceive a stable visual world despite the incessant fixational motion of their eyes. Current theories assume these processes to rely solely on the visual input to the retina, without contributions from motor and/or proprioceptive sources. Here we show that contrary to this widespread assumption, the visual system has access to high-resolution extra-retinal knowledge of fixational eye motion and uses it to deduce spatial relations. Building on recent advances in gaze-contingent display control, we created a spatial discrimination task in which the stimulus configuration was entirely determined by oculomotor activity. Our results show that humans correctly infer geometrical relations in the absence of spatial information on the retina and accurately combine high-resolution extraretinal monitoring of gaze displacement with retinal signals. These findings reveal a sensory-motor strategy for encoding space, in which fine oculomotor knowledge is used to interpret the fixational input to the retina.
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11
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Maruta J. Lasting alteration of spatial orientation induced by passive motion in rabbits and its possible relevance to mal de débarquement syndrome. Front Neurol 2023; 14:1110298. [PMID: 36908625 PMCID: PMC9994528 DOI: 10.3389/fneur.2023.1110298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/30/2023] [Indexed: 02/24/2023] Open
Abstract
Background Mal de débarquement syndrome (MdDS) is a chronic disorder of spatial orientation with a persistent false sensation of self-motion, whose onset typically follows prolonged exposure to passive motion of a transport vehicle. Development of similar but transient after-sensations mimicking the exposed motion and associated postural instability, indicative of central vestibular adaptation, are common. The cause of MdDS is thought to be a subsequent failure to readapt to a stationary environment. However, vestibular plasticity pertinent to this illness has not been studied sufficiently. Because the rabbit's eye movement is sensitive to three-dimensional spatial orientation, characterizing maladaptation of the vestibulo-ocular reflex (VOR) induced in the animal may open an approach to understanding MdDS. Methods Three rabbits underwent a series of 2-h conditioning with an unnatural repetitive motion that involved a complex combination of roll, pitch, and yaw movements in a head-based reference frame, consisting of periodic rolling in darkness in a frame of reference that rotated about an earth-vertical axis. Eye movement in three dimensions was sampled during the conditioning stimulus as well as during test stimuli before and up to several days after conditioning. Results During roll-while-rotating conditioning, the roll component of the VOR was compensatory to the oscillation about the corresponding axis, but the pitch component was not, initially prominently phase-leading the head pitch motion but subsequently becoming patently phase-delayed. Unidirectional yaw nystagmus, weak but directionally compensatory to the earth-vertical axis rotation, was seen throughout the period of conditioning. After conditioning, simple side-to-side rolling induced an abnormal yaw ocular drift in the direction that opposed the nystagmus seen during conditioning, indicating a maladaptive change in spatial orientation. The impact of conditioning appeared to be partially retained even after 1 week and could be partially reversed or cumulated depending on the rotation direction in the subsequent conditioning. Conclusion The observed reversible long-term maladaptation of spatial orientation as well as the depth of knowledge available in relation to the vestibular cerebellar circuits in this species support the potential utility of a rabbit model in MdDS research.
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Affiliation(s)
- Jun Maruta
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.,Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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12
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Eye drift during fixation predicts visual acuity. Proc Natl Acad Sci U S A 2022; 119:e2200256119. [PMID: 36442088 PMCID: PMC9894113 DOI: 10.1073/pnas.2200256119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Visual acuity is commonly assumed to be determined by the eye optics and spatial sampling in the retina. Unlike a camera, however, the eyes are never stationary during the acquisition of visual information; a jittery motion known as ocular drift incessantly displaces stimuli over many photoreceptors. Previous studies have shown that acuity is impaired in the absence of retinal image motion caused by eye drift. However, the relation between individual drift characteristics and acuity remains unknown. Here, we show that a) healthy emmetropes exhibit a large variability in their amount of drift and that b) these differences profoundly affect the structure of spatiotemporal signals to the retina. We further show that c) the spectral distribution of the resulting luminance modulations strongly correlates with individual visual acuity and that d) natural intertrial fluctuations in the amount of drift modulate acuity. As a consequence, in healthy emmetropes, acuity can be predicted from the motor behavior elicited by a simple fixation task, without directly measuring it. These results shed new light on how oculomotor behavior contributes to fine spatial vision.
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13
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Face familiarity revealed by fixational eye movements and fixation-related potentials in free viewing. Sci Rep 2022; 12:20178. [PMID: 36418497 PMCID: PMC9684544 DOI: 10.1038/s41598-022-24603-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Event-related potentials (ERPs) and the oculomotor inhibition (OMI) in response to visual transients are known to be sensitive to stimulus properties, attention, and expectation. We have recently found that the OMI is also sensitive to face familiarity. In natural vision, stimulation of the visual cortex is generated primarily by saccades, and it has been recently suggested that fixation-related potentials (FRPs) share similar components with the ERPs. Here, we investigated whether FRPs and microsaccade inhibition (OMI) in free viewing are sensitive to face familiarity. Observers freely watched a slideshow of seven unfamiliar and one familiar facial images presented randomly for 4-s periods, with multiple images per identity. We measured the occipital fixation-related N1 relative to the P1 magnitude as well as the associated fixation-triggered OMI. We found that the average N1-P1 was significantly smaller and the OMI was shorter for the familiar face, compared with any of the seven unfamiliar faces. Moreover, the P1 was suppressed across saccades for the familiar but not for the unfamiliar faces. Our results highlight the sensitivity of the occipital FRPs to stimulus properties such as face familiarity and advance our understanding of the integration process across successive saccades in natural vision.
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14
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Fixation-related saccadic inhibition in free viewing in response to stimulus saliency. Sci Rep 2022; 12:6619. [PMID: 35459790 PMCID: PMC9033846 DOI: 10.1038/s41598-022-10605-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 04/11/2022] [Indexed: 01/04/2023] Open
Abstract
Microsaccades that occur during fixation were studied extensively in response to transient stimuli, showing a typical inhibition (Oculomotor Inhibition, OMI), and a later release with a latency that depends on stimulus saliency, attention, and expectations. Here, we investigated the hypothesis that in free viewing every saccade provides a new transient stimulation that should result in a stimulus-dependent OMI like a flashed presentation during fixation. Participants (N = 16) freely inspected static displays of randomly oriented Gabor texture images, with varied contrast and spatial frequency (SF) for periods of 10 s each. Eye tracking recordings were divided into epochs triggered by saccade landing (> 1 dva), and microsaccade latency relative to fixation onset was computed (msRT). We found that the msRT in free viewing was shorter for more salient stimuli (higher contrast or lower SF), as previously found for flashed stimuli. It increased with saccade size and decreased across successive saccades, but only for higher contrast, suggesting contrast-dependent repetition enhancement in free viewing. Our results indicate that visual stimulus-dependent inhibition of microsaccades also applies to free viewing. These findings are in agreement with the similarity found between event-related and fixation-related potentials and open the way for studies combining both approaches to study natural vision.
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15
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Kadosh O, Bonneh YS. Involuntary oculomotor inhibition markers of saliency and deviance in response to auditory sequences. J Vis 2022; 22:8. [PMID: 35475911 PMCID: PMC9055552 DOI: 10.1167/jov.22.5.8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Our eyes move constantly but are often inhibited momentarily in response to external stimuli (oculomotor inhibition [OMI]), depending on the stimulus saliency, anticipation, and attention. Previous studies have shown prolonged OMI for auditory oddballs; however, they required counting the oddballs, possibly reflecting voluntary attention. Here, we investigated whether the “passive” OMI response to auditory deviants can provide a quantitative measure of deviance strength (pitch difference) and studied its dependence on the inter-trial interval (ITI). Participants fixated centrally and passively listened to repeated short sequences of pure tones that contained a deviant tone either regularly or with 20% probability (oddballs). In an “active” control experiment, participants counted the deviant or the standard. As in previous studies, the results showed prolonged microsaccade inhibition and increased pupil dilation following the rare deviant tone. Earlier inhibition onset was found in proportion to the pitch deviance (the saliency effect), and a later release was found for oddballs, but only for ITI <2.5 seconds. The active control experiment showed similar results when counting the deviant but longer OMI for the standard when counting it. Taken together, these results suggest that OMI provides involuntary markers of saliency and deviance, which can be obtained without the participant's response.
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Affiliation(s)
- Oren Kadosh
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.,
| | - Yoram S Bonneh
- School of Optometry and Vision Science, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel., https://yorambonneh.wixsite.com/bonneh-lab
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16
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Fast and nonuniform dynamics of perisaccadic vision in the central fovea. Proc Natl Acad Sci U S A 2021; 118:2101259118. [PMID: 34497123 PMCID: PMC8449317 DOI: 10.1073/pnas.2101259118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2021] [Indexed: 01/05/2023] Open
Abstract
Humans shift their gaze more frequently than their heart beats. These rapid eye movements (saccades) enable high visual acuity by redirecting the tiny high-resolution region of the retina (the foveola). But in doing so, they abruptly sweep the image across receptors, raising questions on how the visual system achieves stable percepts. It is well established that visual sensitivity is transiently attenuated during saccades. However, little is known about the time course of foveal vision despite its disproportionate importance, as technical challenges have so far prevented study of how saccades affect the foveola. Here we show that saccades modulate this region in a nonuniform manner, providing stronger and faster changes at its very center, a locus with higher sensitivity. Humans use rapid eye movements (saccades) to inspect stimuli with the foveola, the region of the retina where receptors are most densely packed. It is well established that visual sensitivity is generally attenuated during these movements, a phenomenon known as saccadic suppression. This effect is commonly studied with large, often peripheral, stimuli presented during instructed saccades. However, little is known about how saccades modulate the foveola and how the resulting dynamics unfold during natural visual exploration. Here we measured the foveal dynamics of saccadic suppression in a naturalistic high-acuity task, a task designed after primates’ social grooming, which—like most explorations of fine patterns—primarily elicits minute saccades (microsaccades). Leveraging on recent advances in gaze-contingent display control, we were able to systematically map the perisaccadic time course of sensitivity across the foveola. We show that contrast sensitivity is not uniform across this region and that both the extent and dynamics of saccadic suppression vary within the foveola. Suppression is stronger and faster in the most central portion, where sensitivity is generally higher and selectively rebounds at the onset of a new fixation. These results shed light on the modulations experienced by foveal vision during the saccade-fixation cycle and explain some of the benefits of microsaccades.
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17
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Guzhang Y, Shelchkova N, Ezzo R, Poletti M. Transient perceptual enhancements resulting from selective shifts of exogenous attention in the central fovea. Curr Biol 2021; 31:2698-2703.e2. [PMID: 33930304 PMCID: PMC8763350 DOI: 10.1016/j.cub.2021.03.105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/01/2021] [Accepted: 03/31/2021] [Indexed: 12/01/2022]
Abstract
Exogenous attention, a powerful adaptive tool that quickly and involuntarily orients processing resources to salient stimuli, has traditionally been studied in the lower-resolution parafoveal and peripheral visual field.1-4 It is not known whether and how it operates across the 1° central fovea where visual resolution peaks.5,6 Here we investigated the dynamics of exogenous attention in the foveola. To circumvent the challenges posed by fixational eye movements at this scale, we used high-precision eye-tracking and gaze-contingent display control for retinal stabilization.7 High-acuity stimuli were briefly presented foveally at varying delays following an exogenous cue. Attended and unattended locations were just a few arcminutes away from the preferred locus of fixation. Our results show that for short temporal delays, observers' ability to discriminate fine detail is enhanced at the cued location. This enhancement is highly localized and does not extend to the nearby locations only 16' away. On a longer timescale, instead, we report an inverse effect: paradoxically, acuity is sharper at the unattended locations, resembling the phenomenon of inhibition of return at much larger eccentricities.8-10 Although exogenous attention represents a mechanism for low-cost monitoring of the environment in the extrafoveal space, these findings show that, in the foveola, it transiently modulates vision of detail with a high degree of resolution. Together with inhibition of return, it may aid visual exploration of complex foveal stimuli.11.
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Affiliation(s)
- Yue Guzhang
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA
| | - Natalya Shelchkova
- Program in Computational Neuroscience, University of Chicago, Chicago, IL, USA
| | - Rania Ezzo
- Department of Psychology, New York University, New York, NY, USA
| | - Martina Poletti
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA; Department of Neuroscience, University of Rochester, Rochester, NY, USA; Center for Visual Science, University of Rochester, Rochester, NY, USA.
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18
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Abe T, Mishima K, Kitamura S, Hida A, Inoue Y, Mizuno K, Kaida K, Nakazaki K, Motomura Y, Maruo K, Ohta T, Furukawa S, Dinges DF, Ogata K. Tracking intermediate performance of vigilant attention using multiple eye metrics. Sleep 2021; 43:5733056. [PMID: 32040590 DOI: 10.1093/sleep/zsz219] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/01/2019] [Indexed: 11/14/2022] Open
Abstract
Vigilance deficits account for a substantial number of accidents and errors. Current techniques to detect vigilance impairment measure only the most severe level evident in eyelid closure and falling asleep, which is often too late to avoid an accident or error. The present study sought to identify ocular biometrics of intermediate impairment of vigilance and develop a new technique that could detect a range of deficits in vigilant attention (VA). Sixteen healthy adults performed well-validated Psychomotor Vigilance Test (PVT) for tracking vigilance attention while undergoing simultaneous recording of eye metrics every 2 hours during 38 hours of continuous wakefulness. A novel marker was found that measured VA when the eyes were open-the prevalence of microsaccades. Notably, the prevalence of microsaccades decreased in response to sleep deprivation and time-on-task. In addition, a novel algorithm for detecting multilevel VA was developed, which estimated performance on the PVT by integrating the novel marker with other eye-related indices. The novel algorithm also tracked changes in intermediate level of VA (specific reaction times in the PVT, i.e. 300-500 ms) during prolonged time-on-task and sleep deprivation, which had not been tracked previously by conventional techniques. The implication of the findings is that this novel algorithm, named "eye-metrical estimation version of the PVT: PVT-E," can be used to reduce human-error-related accidents caused by vigilance impairment even when its level is intermediate.
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Affiliation(s)
- Takashi Abe
- Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan.,International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.,Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Kazuo Mishima
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.,Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.,Department of Neuropsychiatry, Akita University Graduate School of Medicine, Akita-city, Akita, Japan
| | - Shingo Kitamura
- Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Akiko Hida
- Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Yuichi Inoue
- Department of Somnology, Tokyo Medical University, Shinjuku-Ku, Tokyo, Japan
| | - Koh Mizuno
- Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan.,Faculty of Education, Tohoku Fukushi University, Sendai, Miyagi, Japan
| | - Kosuke Kaida
- Automotive Human Factors Research Center, Department of Information Technology and Human Factors, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Kyoko Nakazaki
- Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Yuki Motomura
- Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.,Department of Human Science, Faculty of Design, Kyushu University, Minami-Ku, Fukuoka, Japan
| | - Kazushi Maruo
- Department of Biostatistics, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Toshiko Ohta
- Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
| | - Satoshi Furukawa
- Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
| | - David F Dinges
- Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Katsuhiko Ogata
- Astronaut and Operation Control Unit, Human Spaceflight Technology Directorate, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
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19
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Hafed ZM, Chen CY, Tian X, Baumann MP, Zhang T. Active vision at the foveal scale in the primate superior colliculus. J Neurophysiol 2021; 125:1121-1138. [PMID: 33534661 DOI: 10.1152/jn.00724.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The primate superior colliculus (SC) has recently been shown to possess both a large foveal representation as well as a varied visual processing repertoire. This structure is also known to contribute to eye movement generation. Here, we describe our current understanding of how SC visual and movement-related signals interact within the realm of small eye movements associated with the foveal scale of visuomotor behavior. Within the SC's foveal representation, there is a full spectrum of visual, visual-motor, and motor-related discharge for fixational eye movements. Moreover, a substantial number of neurons only emit movement-related discharge when microsaccades are visually guided, but not when similar movements are generated toward a blank. This represents a particularly striking example of integrating vision and action at the foveal scale. Beyond that, SC visual responses themselves are strongly modulated, and in multiple ways, by the occurrence of small eye movements. Intriguingly, this impact can extend to eccentricities well beyond the fovea, causing both sensitivity enhancement and suppression in the periphery. Because of large foveal magnification of neural tissue, such long-range eccentricity effects are neurally warped into smaller differences in anatomical space, providing a structural means for linking peripheral and foveal visual modulations around fixational eye movements. Finally, even the retinal-image visual flows associated with tiny fixational eye movements are signaled fairly faithfully by peripheral SC neurons with relatively large receptive fields. These results demonstrate how studying active vision at the foveal scale represents an opportunity for understanding primate vision during natural behaviors involving ever-present foveating eye movements.NEW & NOTEWORTHY The primate superior colliculus (SC) is ideally suited for active vision at the foveal scale: it enables detailed foveal visual analysis by accurately driving small eye movements, and it also possesses a visual processing machinery that is sensitive to active eye movement behavior. Studying active vision at the foveal scale in the primate SC is informative for broader aspects of active perception, including the overt and covert processing of peripheral extra-foveal visual scene locations.
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Affiliation(s)
- Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, Tübingen University, Tübingen, Germany.,Hertie Institute for Clinical Brain Research, Tübingen University, Tübingen, Germany
| | - Chih-Yang Chen
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan
| | - Xiaoguang Tian
- University of Pittsburgh Brain Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Matthias P Baumann
- Werner Reichardt Centre for Integrative Neuroscience, Tübingen University, Tübingen, Germany.,Hertie Institute for Clinical Brain Research, Tübingen University, Tübingen, Germany
| | - Tong Zhang
- Werner Reichardt Centre for Integrative Neuroscience, Tübingen University, Tübingen, Germany.,Hertie Institute for Clinical Brain Research, Tübingen University, Tübingen, Germany
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20
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Canales-Johnson A, Lanfranco RC, Morales JP, Martínez-Pernía D, Valdés J, Ezquerro-Nassar A, Rivera-Rei Á, Ibanez A, Chennu S, Bekinschtein TA, Huepe D, Noreika V. In your phase: neural phase synchronisation underlies visual imagery of faces. Sci Rep 2021; 11:2401. [PMID: 33504828 PMCID: PMC7840739 DOI: 10.1038/s41598-021-81336-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/05/2021] [Indexed: 01/15/2023] Open
Abstract
Mental imagery is the process through which we retrieve and recombine information from our memory to elicit the subjective impression of “seeing with the mind’s eye”. In the social domain, we imagine other individuals while recalling our encounters with them or modelling alternative social interactions in future. Many studies using imaging and neurophysiological techniques have shown several similarities in brain activity between visual imagery and visual perception, and have identified frontoparietal, occipital and temporal neural components of visual imagery. However, the neural connectivity between these regions during visual imagery of socially relevant stimuli has not been studied. Here we used electroencephalography to investigate neural connectivity and its dynamics between frontal, parietal, occipital and temporal electrodes during visual imagery of faces. We found that voluntary visual imagery of faces is associated with long-range phase synchronisation in the gamma frequency range between frontoparietal electrode pairs and between occipitoparietal electrode pairs. In contrast, no effect of imagery was observed in the connectivity between occipitotemporal electrode pairs. Gamma range synchronisation between occipitoparietal electrode pairs predicted subjective ratings of the contour definition of imagined faces. Furthermore, we found that visual imagery of faces is associated with an increase of short-range frontal synchronisation in the theta frequency range, which temporally preceded the long-range increase in the gamma synchronisation. We speculate that the local frontal synchrony in the theta frequency range might be associated with an effortful top-down mnemonic reactivation of faces. In contrast, the long-range connectivity in the gamma frequency range along the fronto-parieto-occipital axis might be related to the endogenous binding and subjective clarity of facial visual features.
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Affiliation(s)
- Andrés Canales-Johnson
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK. .,Vicerrectoría de Investigación y Posgrado, Universidad Católica del Maule, Talca, Chile.
| | - Renzo C Lanfranco
- Department of Psychology, University of Edinburgh, Edinburgh, UK.,Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Juan Pablo Morales
- Facultad de Psicología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Joaquín Valdés
- Escuela de Psicología, Universidad Adolfo Ibáñez, Santiago, Chile
| | | | | | - Agustín Ibanez
- Escuela de Psicología, Universidad Adolfo Ibáñez, Santiago, Chile.,Center for Social and Cognitive Neuroscience (CSCN), Latin American Institute of Brain Health (BrainLat), Universidad Adolfo Ibanez, Santiago, Chile.,National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.,Universidad Autónoma del Caribe, Barranquilla, Colombia.,Cognitive Neurosience Center (CNC), Universidad de San Andrés, Buenos Aires, Argentina.,Global Brain Health Institute (GBHI), University of California San Francisco (UCSF), San Francisco, USA
| | - Srivas Chennu
- School of Computing, University of Kent, Chatham Maritime, UK.,Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | | | - David Huepe
- Escuela de Psicología, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Valdas Noreika
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK.,Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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21
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Abstract
Despite recent advances on the mechanisms and purposes of fine oculomotor behavior, a rigorous assessment of the precision and accuracy of the smallest saccades is still lacking. Yet knowledge of how effectively these movements shift gaze is necessary for understanding their functions and is helpful in further elucidating their motor underpinnings. Using a combination of high-resolution eye-tracking and gaze-contingent control, here we examined the accuracy and precision of saccades aimed toward targets ranging from [Formula: see text] to [Formula: see text] eccentricity. We show that even small saccades of just 14-[Formula: see text] are very effective in centering the stimulus on the retina. Furthermore, we show that for a target at any given eccentricity, the probability of eliciting a saccade depends on its efficacy in reducing the foveal offset. The pattern of results reported here is consistent with current knowledge on the motor mechanisms of microsaccade production.
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Affiliation(s)
- Martina Poletti
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, 14627, USA.
- Department of Neuroscience, University of Rochester, Rochester, NY, 14627, USA.
- Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA.
| | - Janis Intoy
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA
- Graduate Program for Neuroscience, Boston University, Boston, MA, 02215, USA
| | - Michele Rucci
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, 14627, USA
- Center for Visual Science, University of Rochester, Rochester, NY, 14627, USA
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22
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Malevich T, Buonocore A, Hafed ZM. Rapid stimulus-driven modulation of slow ocular position drifts. eLife 2020; 9:e57595. [PMID: 32758358 PMCID: PMC7442486 DOI: 10.7554/elife.57595] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 08/05/2020] [Indexed: 11/17/2022] Open
Abstract
The eyes are never still during maintained gaze fixation. When microsaccades are not occurring, ocular position exhibits continuous slow changes, often referred to as drifts. Unlike microsaccades, drifts remain to be viewed as largely random eye movements. Here we found that ocular position drifts can, instead, be very systematically stimulus-driven, and with very short latencies. We used highly precise eye tracking in three well trained macaque monkeys and found that even fleeting (~8 ms duration) stimulus presentations can robustly trigger transient and stimulus-specific modulations of ocular position drifts, and with only approximately 60 ms latency. Such drift responses are binocular, and they are most effectively elicited with large stimuli of low spatial frequency. Intriguingly, the drift responses exhibit some image pattern selectivity, and they are not explained by convergence responses, pupil constrictions, head movements, or starting eye positions. Ocular position drifts have very rapid access to exogenous visual information.
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Affiliation(s)
- Tatiana Malevich
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen UniversityTuebingenGermany
- Hertie Institute for Clinical Brain Research, Tuebingen UniversityTuebingenGermany
- Graduate School of Neural and Behavioural Sciences, International Max-Planck Research School, Tuebingen UniversityTuebingenGermany
| | - Antimo Buonocore
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen UniversityTuebingenGermany
- Hertie Institute for Clinical Brain Research, Tuebingen UniversityTuebingenGermany
| | - Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, Tuebingen UniversityTuebingenGermany
- Hertie Institute for Clinical Brain Research, Tuebingen UniversityTuebingenGermany
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23
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Abstract
It is known that attention shifts prior to a saccade to start processing the saccade target before it lands in the foveola, the high-resolution region of the retina. Yet, once the target is foveated, microsaccades, tiny saccades maintaining the fixated object within the fovea, continue to occur. What is the link between these eye movements and attention? There is growing evidence that these eye movements are associated with covert shifts of attention in the visual periphery, when the attended stimuli are presented far from the center of gaze. Yet, microsaccades are primarily used to explore complex foveal stimuli and to optimize fine spatial vision in the foveola, suggesting that the influences of microsaccades on attention may predominantly impact vision at this scale. To address this question we tracked gaze position with high precision and briefly presented high-acuity stimuli at predefined foveal locations right before microsaccade execution. Our results show that visual discrimination changes prior to microsaccade onset. An enhancement occurs at the microsaccade target location. This modulation is highly selective and it is coupled with a drastic impairment at the opposite foveal location, just a few arcminutes away. This effect is strongest when stimuli are presented closer to the eye movement onset time. These findings reveal that the link between attention and microsaccades is deeper than previously thought, exerting its strongest effects within the foveola. As a result, during fixation, foveal vision is constantly being reshaped both in space and in time with the occurrence of microsaccades.
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24
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Hauperich AK, Young LK, Smithson HE. What makes a microsaccade? A review of 70 years of research prompts a new detection method. J Eye Mov Res 2020; 12. [PMID: 33828754 PMCID: PMC7962681 DOI: 10.16910/jemr.12.6.13] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
A new method for detecting microsaccades in eye-movement data is presented, following a review of reported microsaccade properties between the 1940s and today. The review focuses on the parameter ranges within which certain physical markers of microsaccades are thought to occur, as well as any features of microsaccades that have been stably reported over time. One feature of microsaccades, their binocularity, drives the new microsaccade detection method. The binocular correlation method for microsaccade detection is validated on two datasets of binocular eye-movements recorded using video-based systems: one collected as part of this study, and one from Nyström et al, 2017. Comparisons between detection methods are made using precision-recall statistics. This confirms that the binocular correlation method performs well when compared to manual coders and performs favourably compared to the commonly used Engbert & Kliegl (2003) method with subsequent modifications (Engbert & Mergenthaler, 2006). The binocular correlation microsaccade detection method is easy to implement and MATLAB code is made available to download.
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25
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Badler JB, Watamaniuk SNJ, Heinen SJ. A common mechanism modulates saccade timing during pursuit and fixation. J Neurophysiol 2019; 122:1981-1988. [PMID: 31533016 DOI: 10.1152/jn.00198.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Smooth pursuit is punctuated by catch-up saccades, which are thought to automatically correct sensory errors in retinal position and velocity. Recent studies have shown that the timing of catch-up saccades is susceptible to cognitive modulation, as is the timing of fixational microsaccades. Are the timing of catchup and microsaccades thus modulated by the same mechanism? Here, we test directly whether pursuit catch-up saccades and fixational microsaccades exhibit the same temporal pattern of task-related bursts and subsidence. Observers pursued a linear array of 15 alphanumeric characters that translated across the screen and simultaneously performed a character identification task on it. At a fixed time, a cue briefly surrounded the central element to specify it as the pursuit target. After a random delay, a probe (E or 3) appeared briefly at a randomly selected character location, and observers identified it. For comparison, a fixation condition was also tested with trial parameters identical to the pursuit condition, except that the array remained stationary. We found that during both pursuit and fixation tasks, saccades paused after the cue and then rebounded as expected but also subsided in anticipation of the task. The time courses of the reactive pause, rebound, and anticipatory subsidence were similar, and idiosyncratic subject behavior was consistent across pursuit and fixation. The results provide evidence for a common mechanism of saccade control during pursuit and fixation, which is predictive as well as reactive and has an identifiable temporal signature in individual observers.NEW & NOTEWORTHY During natural scene viewing, voluntary saccades reorient the fovea to different locations for high-acuity viewing. Less is known about small "microsaccades" that also occur when fixating stationary objects and "catch-up saccades" that occur during smooth pursuit of moving objects. We provide evidence that microsaccade and catch-up saccade frequencies are generally modulated by the same mechanism. Furthermore, on a finer time scale the mechanism operates differently in different observers, suggesting that neural saccade generators are individually unique.
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Affiliation(s)
- Jeremy B Badler
- Smith-Kettlewell Eye Research Institute, San Francisco, California
| | - Scott N J Watamaniuk
- Smith-Kettlewell Eye Research Institute, San Francisco, California.,Wright State University, Dayton, Ohio
| | - Stephen J Heinen
- Smith-Kettlewell Eye Research Institute, San Francisco, California
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26
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Cebolla AM, Cheron G. Understanding Neural Oscillations in the Human Brain: From Movement to Consciousness and Vice Versa. Front Psychol 2019; 10:1930. [PMID: 31507490 PMCID: PMC6718699 DOI: 10.3389/fpsyg.2019.01930] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/06/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Ana Maria Cebolla
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, Brussels, Belgium
| | - Guy Cheron
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, Brussels, Belgium.,Laboratory of Electrophysiology, Université de Mons-Hainaut, Mons, Belgium
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