1
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Hooge ITC, Niehorster DC, Nyström M, Hessels RS. Large eye-head gaze shifts measured with a wearable eye tracker and an industrial camera. Behav Res Methods 2024:10.3758/s13428-023-02316-w. [PMID: 38200239 DOI: 10.3758/s13428-023-02316-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2023] [Indexed: 01/12/2024]
Abstract
We built a novel setup to record large gaze shifts (up to 140[Formula: see text]). The setup consists of a wearable eye tracker and a high-speed camera with fiducial marker technology to track the head. We tested our setup by replicating findings from the classic eye-head gaze shift literature. We conclude that our new inexpensive setup is good enough to investigate the dynamics of large eye-head gaze shifts. This novel setup could be used for future research on large eye-head gaze shifts, but also for research on gaze during e.g., human interaction. We further discuss reference frames and terminology in head-free eye tracking. Despite a transition from head-fixed eye tracking to head-free gaze tracking, researchers still use head-fixed eye movement terminology when discussing world-fixed gaze phenomena. We propose to use more specific terminology for world-fixed phenomena, including gaze fixation, gaze pursuit, and gaze saccade.
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Affiliation(s)
- Ignace T C Hooge
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands.
| | - Diederick C Niehorster
- Lund University Humanities Lab and Department of Psychology, Lund University, Lund, Sweden
| | - Marcus Nyström
- Lund University Humanities Lab, Lund University, Lund, Sweden
| | - Roy S Hessels
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
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2
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Willett SM, Maenner SK, Mayo JP. The perceptual consequences and neurophysiology of eye blinks. Front Syst Neurosci 2023; 17:1242654. [PMID: 37654528 PMCID: PMC10466800 DOI: 10.3389/fnsys.2023.1242654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 08/02/2023] [Indexed: 09/02/2023] Open
Abstract
A hand passing in front of a camera produces a large and obvious disruption of a video. Yet the closure of the eyelid during a blink, which lasts for hundreds of milliseconds and occurs thousands of times per day, typically goes unnoticed. What are the neural mechanisms that mediate our uninterrupted visual experience despite frequent occlusion of the eyes? Here, we review the existing literature on the neurophysiology, perceptual consequences, and behavioral dynamics of blinks. We begin by detailing the kinematics of the eyelid that define a blink. We next discuss the ways in which blinks alter visual function by occluding the pupil, decreasing visual sensitivity, and moving the eyes. Then, to anchor our understanding, we review the similarities between blinks and other actions that lead to reductions in visual sensitivity, such as saccadic eye movements. The similarity between these two actions has led to suggestions that they share a common neural substrate. We consider the extent of overlap in their neural circuits and go on to explain how recent findings regarding saccade suppression cast doubt on the strong version of the shared mechanism hypothesis. We also evaluate alternative explanations of how blink-related processes modulate neural activity to maintain visual stability: a reverberating corticothalamic loop to maintain information in the face of lid closure; and a suppression of visual transients related to lid closure. Next, we survey the many areas throughout the brain that contribute to the execution of, regulation of, or response to blinks. Regardless of the underlying mechanisms, blinks drastically attenuate our visual abilities, yet these perturbations fail to reach awareness. We conclude by outlining opportunities for future work to better understand how the brain maintains visual perception in the face of eye blinks. Future work will likely benefit from incorporating theories of perceptual stability, neurophysiology, and novel behavior paradigms to address issues central to our understanding of natural visual behavior and for the clinical rehabilitation of active vision.
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Affiliation(s)
- Shawn M. Willett
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah K. Maenner
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
| | - J. Patrick Mayo
- Department of Ophthalmology, Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
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3
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Callara AL, Greco A, Scilingo EP, Bonfiglio L. Neuronal correlates of eyeblinks are an expression of primary consciousness phenomena. Sci Rep 2023; 13:12617. [PMID: 37537328 PMCID: PMC10400571 DOI: 10.1038/s41598-023-39500-z] [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: 06/16/2022] [Accepted: 07/26/2023] [Indexed: 08/05/2023] Open
Abstract
The blinking rate far exceeds that required for moistening the cornea and changes depending on whether a person is resting or engaged in cognitive tasks. During ecological cognitive tasks (such as speaking, reading, and watching videos), blinks occur at breakpoints of attention suggesting a role in information segmentation, but the close relationship between cognition dynamics and blink timing still escapes a full understanding. The aim of the present study is to seek (1) if there is a temporal relationship between blink events and the consecutive steps of cognitive processing, and (2) if blink timing and the intensity of blink-related EEG responses are affected by task-relevance of stimuli. Our results show that, in a classical visual oddball task, (i) the occurrence of blinks is influenced by stimuli, irrespective of their relevance, (ii) blinks following relevant stimuli are only apparently delayed due to the need of finalizing a behavioural response, and (iii) stimulus relevance does not affect the intensity of the blink-related EEG response. This evidence reinforce the idea that blinks are not emitted until the last step of the processing sequence has been completed and suggests that blink-related EEG responses are generated by primary consciousness phenomena which are considered by their nature non-modulable (all-or-nothing) phenomena.
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Affiliation(s)
- Alejandro Luis Callara
- Dipartimento di Ingegneria dell'Informazione, University of Pisa, Via G. Caruso 16, 56122, Pisa, Italy
- Research Center "E. Piaggio", University of Pisa, Largo Lucio Lazzarino 1, 56122, Pisa, Italy
| | - Alberto Greco
- Dipartimento di Ingegneria dell'Informazione, University of Pisa, Via G. Caruso 16, 56122, Pisa, Italy
- Research Center "E. Piaggio", University of Pisa, Largo Lucio Lazzarino 1, 56122, Pisa, Italy
| | - Enzo Pasquale Scilingo
- Dipartimento di Ingegneria dell'Informazione, University of Pisa, Via G. Caruso 16, 56122, Pisa, Italy
- Research Center "E. Piaggio", University of Pisa, Largo Lucio Lazzarino 1, 56122, Pisa, Italy
| | - Luca Bonfiglio
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
- Unit of Developmental Neurorehabilitation, Maternal and Child Department, Pisa University Hospital, Pisa, Italy.
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4
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Spadacenta S, Dicke PW, Thier P. A prosocial function of head-gaze aversion and head-cocking in common marmosets. Primates 2022; 63:535-546. [PMID: 35838928 PMCID: PMC9463209 DOI: 10.1007/s10329-022-00997-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 06/17/2022] [Indexed: 11/24/2022]
Abstract
Gaze aversion is a behavior adopted by several mammalian and non-mammalian species in response to eye contact, and is usually interpreted as a reaction to a perceived threat. Unlike many other primate species, common marmosets (Callithrix jacchus) are thought to have a high tolerance for direct gaze, barely exhibiting gaze avoidance towards conspecifics and humans. Here we show that this does not hold for marmosets interacting with a familiar experimenter who suddenly establishes eye contact in a playful interaction (peekaboo). Video footage synchronously recorded from the perspective of the marmoset and the experimenter showed that the monkeys consistently alternated between eye contact and head-gaze aversion, and that these responses were often preceded by head-cocking. We hypothesize that this behavioral strategy helps marmosets to temporarily disengage from emotionally overwhelming social stimulation due to sight of another individual's face, in order to prepare for a new round of affiliative face-to-face interactions.
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Affiliation(s)
- Silvia Spadacenta
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
| | - Peter W Dicke
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Peter Thier
- Cognitive Neurology Laboratory, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
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5
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Kirchner J, Watson TL, Busch NA, Lappe M. Timing and kinematics of horizontal within-blink saccades measured using EOG. J Neurophysiol 2022; 127:1655-1668. [PMID: 35647737 DOI: 10.1152/jn.00076.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Eye blinks are the brief closures of the lid. They are accompanied by a co-contraction of the eye muscles that temporarily pulls the whole eyeball back into its socket. When blinks occur together with execution of saccadic gaze shifts, they interfere with the saccadic premotor circuit, causing these within-blink saccades to be slower than normal and also time-locked to blinks. In order to analyse the trajectory of within-blink saccades, the subtraction of the entangled blink-related eye movement is required. Here we propose a combination of principal component analysis (PCA) and a regression model to subtract the blink-related component of the eye movement based on the respective blink metrics. We used electrooculography (EOG) to measure eye and lid movements of twelve participants who performed saccades with and without blinks. We found that within-blink saccades are slower than without-blink saccades and are tightly coupled in time to blink onset. Surprisingly, in some participants we observed large dynamic overshoots of up to 15° for saccades of only 5° amplitude. This finding challenges the current view that within-blink saccades are programmed as slow, but straight, saccades. We hypothesise that the dynamic overshoots could either be attributed to inhibition of omnipause neurons during blinks, the simultaneous co-contraction of extraocular muscles or a combination of both.
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Affiliation(s)
- Johannes Kirchner
- Institute for Psychology, grid.5949.1University of Münster, Münster, Germany
| | - Tamara Lea Watson
- School of Psychology, The University of Western Sydney, Sydney, Australia
| | - Niko A Busch
- Westfälische Wilhelms-Universität Münster, Münster, Nordrhein-Westfalen, Germany
| | - Markus Lappe
- Otto-Creutzfeldt Center for Cognitive and Behavioural Neuroscience, University of Muenster
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6
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Ocular measures during associative learning predict recall accuracy. Int J Psychophysiol 2021; 166:103-115. [PMID: 34052234 DOI: 10.1016/j.ijpsycho.2021.05.010] [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: 11/01/2019] [Revised: 05/19/2021] [Accepted: 05/25/2021] [Indexed: 11/20/2022]
Abstract
The ability to form associations between stimuli and commit those associations to memory is a cornerstone of human cognition. Dopamine and noradrenaline are critical neuromodulators implicated in a range of cognitive functions, including learning and memory. Eye blink rate (EBR) and pupil diameter have been shown to index dopaminergic and noradrenergic activity. Here, we examined how these ocular measures relate to accuracy in a paired-associate learning task where participants (N = 73) learned consistent object-location associations over eight trials consisting of pre-trial fixation, encoding, delay, and retrieval epochs. In order to examine how within-subject changes and between-subject changes in ocular metrics related to accuracy, we mean centered individual metric values on each trial based on within-person and across-subject means for each epoch. Within-participant variation in EBR was positively related to accuracy in both encoding and delay epochs: faster EBR within the individual predicted better retrieval. Differences in EBR across participants was negatively related to accuracy in the encoding epoch and in early trials of the pre-trial fixation: faster EBR, relative to other subjects, predicted poorer retrieval. Visual scanning behavior in pre-trial fixation and delay epochs was also positively related to accuracy in early trials: more scanning predicted better retrieval. We found no relationship between pupil diameter and accuracy. These results provide novel evidence supporting the utility of ocular metrics in illuminating cognitive and neurobiological mechanisms of paired-associate learning.
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7
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A songbird strategically modifies its blinking behavior when viewing human faces. Anim Cogn 2021; 24:787-801. [PMID: 33501597 DOI: 10.1007/s10071-021-01476-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 01/04/2021] [Accepted: 01/08/2021] [Indexed: 10/22/2022]
Abstract
Even though blinking is necessary to maintain clear vision in many species, blinking is likely costly because it temporarily impairs vision. Given this cost, individuals can strategically modify their blinking behavior to minimize information loss. We tested whether a songbird species modifies its blinking behavior when viewing potential threats (human faces). We recorded the blinking behavior of captive great-tailed grackles (Quiscalus mexicanus) before, during, and after they viewed human face stimuli or control stimuli (tree bark as well as scrambled versions of human faces and tree bark). We found that the birds inhibited their blinking behavior the most when viewing human faces versus controls. In addition, they inhibited their blinking behavior more when viewing human faces that were directed rather than averted. Furthermore, when viewing the human faces, their blinking behavior was modified based on reactivity. These results suggest that a songbird can strategically modify its blinking behavior based on its perceived level of risk.
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8
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Wunderlich A, Gramann K. Eye movement-related brain potentials during assisted navigation in real-world environments. Eur J Neurosci 2020; 54:8336-8354. [PMID: 33369773 DOI: 10.1111/ejn.15095] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/30/2022]
Abstract
Conducting neuroscience research in the real-world remains challenging because of movement- and environment-related artifacts as well as missing control over stimulus presentation. The present study overcame these restrictions by mobile electroencephalography (EEG) and data-driven analysis approaches during a real-world navigation task. During assisted navigation through an unfamiliar city environment, participants received either standard or landmark-based auditory navigation instructions. EEG data were recorded continuously during navigation. Saccade- and blink-events as well as gait-related EEG activity were extracted from sensor level data. Brain activity associated with the navigation task was identified by subsequent source-based cleaning of non-brain activity and unfolding of overlapping event-related potentials. When navigators received landmark-based instructions compared to those receiving standard navigation instructions, the blink-related brain potentials during navigation revealed higher amplitudes at fronto-central leads in a time window starting at 300 ms after blinks, which was accompanied by improved spatial knowledge acquisition tested in follow-up spatial tasks. Replicating improved spatial knowledge acquisition from previous experiments, the present study revealed eye movement-related brain potentials to point to the involvement of higher cognitive processes and increased processing of incoming information during periods of landmark-based instructions. The study revealed neuronal correlates underlying visuospatial information processing during assisted navigation in the real-world providing a new analysis approach for neuroscientific research in freely moving participants in uncontrollable real-world environments.
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Affiliation(s)
- Anna Wunderlich
- Technische Universität Berlin, FG Biopsychologie und Neuroergonomie, Berlin, Germany
| | - Klaus Gramann
- Technische Universität Berlin, FG Biopsychologie und Neuroergonomie, Berlin, Germany.,School of Computer Science, University of Technology Sydney, Sydney, NSW, Australia.,Center for Advanced Neurological Engineering, University of California, San Diego, CA, USA
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9
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Yorzinski JL. Blinking behavior in great‐tailed grackles (
Quiscalus mexicanus
) increases during simulated rainfall. Ethology 2020. [DOI: 10.1111/eth.13003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Jessica L. Yorzinski
- Department of Ecology and Conservation Biology Texas A&M University College Station TX USA
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10
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Does the network model fits neurophysiological abnormalities in blepharospasm? Neurol Sci 2020; 41:2067-2079. [DOI: 10.1007/s10072-020-04347-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/16/2020] [Indexed: 10/24/2022]
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11
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Yorzinski JL, Argubright S. Wind Increases Blinking Behavior in Great-Tailed Grackles (Quiscalus mexicanus). Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00330] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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12
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Liu CC, Ghosh Hajra S, Fickling SD, Pawlowski G, Song X, D'Arcy RCN. Novel Signal Processing Technique for Capture and Isolation of Blink-Related Oscillations Using a Low-Density Electrode Array for Bedside Evaluation of Consciousness. IEEE Trans Biomed Eng 2019; 67:453-463. [PMID: 31059425 DOI: 10.1109/tbme.2019.2915185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Blink-related oscillations derived from electroencephalography (EEG) have recently emerged as an important measure of awareness. Combined with portable EEG hardware with low-density electrode arrays, this neural marker may crucially augment the existing bedside assessments of consciousness in unresponsive patients. Nonetheless, the close relationship between signal characteristics of the neural response of interest and blink-induced oculomotor artifacts poses particular challenges when measuring blink-related oscillations using a point-of-care platform. This study presents a novel denoising approach based on time-frequency (TF) filtering that exploits the differential temporal and spectral features to isolate the neural response from ocular artifact in a low-density array. METHODS We investigated the effectiveness of the TF filtering technique using 64-channel EEG data collected in healthy adults, with focal analysis of the Pz and POz channels. RESULTS TF filtering showed comparable performance in denoising the signal relative to the established gold-standard independent component analysis approach, with strong similarities in morphological characteristics as measured by intraclass correlations (p < 0.001), extent of artifact rejection based on the ocular contamination index (p < 0.006), as well as time- and frequency-domain signal capture (p < 0.05). Results are robust at the individual and group levels, and are crucially validated using raw data from only four electrodes comprising Pz, POz, Fp2, and T7. CONCLUSION These results demonstrate for the first time that TF filtering enables the successful capture and isolation of the blink-related oscillations response using a four-electrode array. SIGNIFICANCE This significantly advances the translation of the blink-related oscillations marker to a point-of-care platform for eventual bedside applications.
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13
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Humans quickly learn to blink strategically in response to environmental task demands. Proc Natl Acad Sci U S A 2018; 115:2246-2251. [PMID: 29444860 DOI: 10.1073/pnas.1714220115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Eye blinking is one of the most frequent human actions. The control of blinking is thought to reflect complex interactions between maintaining clear and healthy vision and influences tied to central dopaminergic functions including cognitive states, psychological factors, and medical conditions. The most imminent consequence of blinking is a temporary loss of vision. Minimizing this loss of information is a prominent explanation for changes in blink rates and temporarily suppressed blinks, but quantifying this loss is difficult, as environmental regularities are usually complex and unknown. Here we used a controlled detection experiment with parametrically generated event statistics to investigate human blinking control. Subjects were able to learn environmental regularities and adapted their blinking behavior strategically to better detect future events. Crucially, our design enabled us to develop a computational model that allows quantifying the consequence of blinking in terms of task performance. The model formalizes ideas from active perception by describing blinking in terms of optimal control in trading off intrinsic costs for blink suppression with task-related costs for missing an event under perceptual uncertainty. Remarkably, this model not only is sufficient to reproduce key characteristics of the observed blinking behavior such as blink suppression and blink compensation but also predicts without further assumptions the well-known and diverse distributions of time intervals between blinks, for which an explanation has long been elusive.
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14
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15
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Eye blinking in an avian species is associated with gaze shifts. Sci Rep 2016; 6:32471. [PMID: 27572457 PMCID: PMC5004160 DOI: 10.1038/srep32471] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 08/09/2016] [Indexed: 11/14/2022] Open
Abstract
Even when animals are actively monitoring their environment, they lose access to visual information whenever they blink. They can strategically time their blinks to minimize information loss and improve visual functioning but we have little understanding of how this process operates in birds. This study therefore examined blinking in freely-moving peacocks (Pavo cristatus) to determine the relationship between their blinks, gaze shifts, and context. Peacocks wearing a telemetric eye-tracker were exposed to a taxidermy predator (Vulpes vulpes) and their blinks and gaze shifts were recorded. Peacocks blinked during the majority of their gaze shifts, especially when gaze shifts were large, thereby timing their blinks to coincide with periods when visual information is already suppressed. They inhibited their blinks the most when they exhibited high rates of gaze shifts and were thus highly alert. Alternative hypotheses explaining the link between blinks and gaze shifts are discussed.
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16
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Haji-Abolhassani I, Guitton D, Galiana HL. Modeling eye-head gaze shifts in multiple contexts without motor planning. J Neurophysiol 2016; 116:1956-1985. [PMID: 27440248 DOI: 10.1152/jn.00605.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/14/2016] [Indexed: 11/22/2022] Open
Abstract
During gaze shifts, the eyes and head collaborate to rapidly capture a target (saccade) and fixate it. Accordingly, models of gaze shift control should embed both saccadic and fixation modes and a mechanism for switching between them. We demonstrate a model in which the eye and head platforms are driven by a shared gaze error signal. To limit the number of free parameters, we implement a model reduction approach in which steady-state cerebellar effects at each of their projection sites are lumped with the parameter of that site. The model topology is consistent with anatomy and neurophysiology, and can replicate eye-head responses observed in multiple experimental contexts: 1) observed gaze characteristics across species and subjects can emerge from this structure with minor parametric changes; 2) gaze can move to a goal while in the fixation mode; 3) ocular compensation for head perturbations during saccades could rely on vestibular-only cells in the vestibular nuclei with postulated projections to burst neurons; 4) two nonlinearities suffice, i.e., the experimentally-determined mapping of tectoreticular cells onto brain stem targets and the increased recruitment of the head for larger target eccentricities; 5) the effects of initial conditions on eye/head trajectories are due to neural circuit dynamics, not planning; and 6) "compensatory" ocular slow phases exist even after semicircular canal plugging, because of interconnections linking eye-head circuits. Our model structure also simulates classical vestibulo-ocular reflex and pursuit nystagmus, and provides novel neural circuit and behavioral predictions, notably that both eye-head coordination and segmental limb coordination are possible without trajectory planning.
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Affiliation(s)
- Iman Haji-Abolhassani
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada; and
| | - Daniel Guitton
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Henrietta L Galiana
- Department of Biomedical Engineering, McGill University, Montreal, Quebec, Canada; and
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17
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Benedetto S, Carbone A, Pedrotti M, Le Fevre K, Bey LAY, Baccino T. Rapid serial visual presentation in reading: The case of Spritz. COMPUTERS IN HUMAN BEHAVIOR 2015. [DOI: 10.1016/j.chb.2014.12.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Pejsa T, Andrist S, Gleicher M, Mutlu B. Gaze and Attention Management for Embodied Conversational Agents. ACM T INTERACT INTEL 2015. [DOI: 10.1145/2724731] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To facilitate natural interactions between humans and embodied conversational agents (ECAs), we need to endow the latter with the same nonverbal cues that humans use to communicate. Gaze cues in particular are integral in mechanisms for communication and management of attention in social interactions, which can trigger important social and cognitive processes, such as establishment of affiliation between people or learning new information. The fundamental building blocks of gaze behaviors are
gaze shifts
: coordinated movements of the eyes, head, and body toward objects and information in the environment. In this article, we present a novel computational model for gaze shift synthesis for ECAs that supports parametric control over coordinated eye, head, and upper body movements. We employed the model in three studies with human participants. In the first study, we validated the model by showing that participants are able to interpret the agent’s gaze direction accurately. In the second and third studies, we showed that by adjusting the participation of the head and upper body in gaze shifts, we can control the strength of the attention signals conveyed, thereby strengthening or weakening their social and cognitive effects. The second study shows that manipulation of eye--head coordination in gaze enables an agent to convey more information or establish stronger affiliation with participants in a teaching task, while the third study demonstrates how manipulation of upper body coordination enables the agent to communicate increased interest in objects in the environment.
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Affiliation(s)
- Tomislav Pejsa
- University of Wisconsin-Madison, Department of Computer Sciences, W. Dayton St., Madison, WI
| | - Sean Andrist
- University of Wisconsin-Madison, Department of Computer Sciences, W. Dayton St., Madison, WI
| | - Michael Gleicher
- University of Wisconsin-Madison, Department of Computer Sciences, W. Dayton St., Madison, WI
| | - Bilge Mutlu
- University of Wisconsin-Madison, Department of Computer Sciences, W. Dayton St., Madison, WI
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19
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Cardona G, Quevedo N. Blinking and Driving: the Influence of Saccades and Cognitive Workload. Curr Eye Res 2013; 39:239-44. [DOI: 10.3109/02713683.2013.841256] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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20
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Bacher L. Development and manipulation of spontaneous eye blinking in the first year: Relationships to context and positive affect. Dev Psychobiol 2013; 56:783-96. [DOI: 10.1002/dev.21148] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 06/07/2013] [Indexed: 11/12/2022]
Affiliation(s)
- L.F. Bacher
- Department of Psychology; SUNY Oswego; 7060 State Rt 104 West Oswego NY 13126
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21
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Abstract
INTRODUCTION The spontaneous blink rate (SBR) is variable in humans. It increases rapidly during childhood before reaching a plateau in adulthood at 10-20 blinks/minute. Our aim was to compare the SBR during different visual tasks in children. METHODS Thirty-nine healthy participants (mean age(SD):13.6(3.5)years, M=21), made horizontal and vertical visually-guided saccades, tracked a horizontal and vertical target, performed horizontal and vertical active sinusoidal head rotations in light and darkness while looking straight ahead (VOR task) or fixated straight ahead and in four directions of gaze. The eyes of each participant were videotaped and reviewed twice to determine the SBR. Parametric and non-parametric tests were used to analyze the data. RESULTS The median SBR during fixation straight ahead was seven blinks/minute, which was similar to the SBR during horizontal saccades and horizontal smooth pursuit tasks. The median SBR during vertical smooth pursuit and vertical saccades were significantly lower than during fixation (p≤0.042). The median SBR during the VOR task in light and horizontal VOR in darkness were significantly higher than during fixation (p=0.019-0.024). CONCLUSIONS The median SBR during visual fixation was lower than that reported previously in 5-14 years-old children during rest or 11-20 years-old subjects during quiet conversation. The median SBR was even lower during vertical smooth pursuit and saccades tasks. This may be due to differences in concentration required for visual fixation in general and vertical visual tasks more specifically. The higher SBR during the VOR may be due to drying of the eyes during head shaking.
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22
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Abstract
Memory-guided saccades are slower than visually guided saccades. The usual explanation for this slowing is that the absence of a visual drive reduces the discharge of neurons in the superior colliculus. We tested a related hypothesis: that the slowing of memory-guided saccades was due also to the more frequent occurrence of gaze-evoked blinks with memory-guided saccades compared with visually guided saccades. We recorded gaze-evoked blinks in three monkeys while they performed visually guided and memory-guided saccades and compared the kinematics of the different saccade types with and without blinks. Gaze-evoked blinks were more common during memory-guided saccades than during visually guided saccades, and the well-established relationship between peak and average velocity for saccades was disrupted by blinking. The occurrence of gaze-evoked blinks was associated with a greater slowing of memory-guided saccades compared with visually guided saccades. Likewise, when blinks were absent, the peak velocity of visually guided saccades was only slightly higher than that of memory-guided saccades. Our results reveal interactions between circuits generating saccades and blink-evoked eye movements. The interaction leads to increased curvature of saccade trajectories and a corresponding decrease in saccade velocity. Consistent with this interpretation, the amount of saccade curvature and slowing increased with gaze-evoked blink amplitude. Thus, although the absence of vision decreases the velocity of memory-guided saccades relative to visually guided saccades somewhat, the cooccurrence of gaze-evoked blinks produces the majority of slowing for memory-guided saccades.
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Affiliation(s)
- Alice S Powers
- Department of Psychology, Stony Brook University, Stony Brook, NY 11794-2500, USA.
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Le BH, Ma X, Deng Z. Live Speech Driven Head-and-Eye Motion Generators. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2012; 18:1902-1914. [PMID: 22392712 DOI: 10.1109/tvcg.2012.74] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper describes a fully automated framework to generate realistic head motion, eye gaze, and eyelid motion simultaneously based on live (or recorded) speech input. Its central idea is to learn separate yet interrelated statistical models for each component (head motion, gaze, or eyelid motion) from a prerecorded facial motion data set: 1) Gaussian Mixture Models and gradient descent optimization algorithm are employed to generate head motion from speech features; 2) Nonlinear Dynamic Canonical Correlation Analysis model is used to synthesize eye gaze from head motion and speech features, and 3) nonnegative linear regression is used to model voluntary eye lid motion and log-normal distribution is used to describe involuntary eye blinks. Several user studies are conducted to evaluate the effectiveness of the proposed speech-driven head and eye motion generator using the well-established paired comparison methodology. Our evaluation results clearly show that this approach can significantly outperform the state-of-the-art head and eye motion generation algorithms. In addition, a novel mocap+video hybrid data acquisition technique is introduced to record high-fidelity head movement, eye gaze, and eyelid motion simultaneously.
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Affiliation(s)
- Binh H Le
- Computer Graphics Laboratory, Department of Computer Science, PGH 309, University of Houston, 4800 Calhoun Road, Houston, TX 77204-30100, USA.
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24
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Oh J, Han M, Peterson BS, Jeong J. Spontaneous eyeblinks are correlated with responses during the Stroop task. PLoS One 2012; 7:e34871. [PMID: 22493720 PMCID: PMC3321041 DOI: 10.1371/journal.pone.0034871] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 03/08/2012] [Indexed: 11/19/2022] Open
Abstract
The timing and frequency of spontaneous eyeblinking is thought to be influenced by ongoing internal cognitive or neurophysiological processes, but how precisely these processes influence the dynamics of eyeblinking is still unclear. This study aimed to better understand the functional role of eyeblinking during cognitive processes by investigating the temporal pattern of eyeblinks during the performance of attentional tasks. The timing of spontaneous eyeblinks was recorded from 28 healthy subjects during the performance of both visual and auditory versions of the Stroop task, and the temporal distributions of eyeblinks were estimated in relation to the timing of stimulus presentation and vocal response during the tasks. We found that the spontaneous eyeblink rate increased during Stroop task performance compared with the resting rate. Importantly, the subjects (17/28 during the visual Stroop, 20/28 during the auditory Stroop) were more likely to blink before a vocal response in both tasks (150–250 msec) and the remaining subjects were more likely to blink soon after the vocal response (200–300 msec), regardless of the stimulus type (congruent or incongruent) or task difficulty. These findings show that spontaneous eyeblinks are closely associated with responses during the performance of the Stroop task on a short time scale and suggest that spontaneous eyeblinks likely signal a shift in the internal cognitive or attentional state of the subjects.
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Affiliation(s)
- Jihoon Oh
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Mookyung Han
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Bradley S. Peterson
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Jaeseung Jeong
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
- * E-mail:
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Krauter EE, Cruickshank BC, Avery MC. Further Evidence for the Independent Reflex-Eliciting and Reflex-Inhibiting Effects of a Startle-Blink Eliciting Stimulus. J PSYCHOPHYSIOL 2012. [DOI: 10.1027/0269-8803/a000068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A small change in the environment (a prepulse) that just precedes a startle-eliciting stimulus can reduce the size of the elicited reflex, but a prepulse does not appear to diminish the ability of the startle-eliciting stimulus to depress a startle response elicited a little later. The reflex-eliciting and reflex-modifying effects of startle stimuli seem to be independent. However, most support for this observation rests on a failure to reject the null hypothesis, and relatively little of this research has employed the acoustic startle blink in human beings. The purpose of the present study was to provide additional evidence on this issue. Participants (n = 20) encountered trials in which a prepulse (p) and two 103 dB(A) blink-eliciting noise bursts (S1 and S2) were given in succession. The prepulse (a synchronous word and tone) occurred 150 ms prior to S1. The prepulse inhibited the startle blink to S1, and S1 depressed the blink elicited 1.5 s later by S2. However, regardless of whether p inhibited the blink to S1, S1 maintained the same capacity to depress the blink to S2. In contrast, a softer S1 (88 dB(A); S1attenuated), which produced a blink nearly matching the size of the prepulse-inhibited blink, did not significantly depress the response to S2. Participants also judged the loudness of S1 and S2. The prepulse reduced the perceived intensity of S1, but much less so than caused by reducing the actual intensity of S1, and proportionally much less so than the prepulse reduced the blink to S1. These results provide further evidence for independent reflex-eliciting and reflex-modifying effects of a startle-eliciting stimulus and argue against the notion that prepulses strongly reduce the general sensory impact of the startle stimulus.
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Affiliation(s)
- E. Evan Krauter
- Department of Psychology, University of South Carolina Upstate, Spartanburg, SC, USA
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26
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Interactions between gaze-evoked blinks and gaze shifts in monkeys. Exp Brain Res 2011; 216:321-39. [PMID: 22083094 DOI: 10.1007/s00221-011-2937-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 10/31/2011] [Indexed: 10/15/2022]
Abstract
Rapid eyelid closure, or a blink, often accompanies head-restrained and head-unrestrained gaze shifts. This study examines the interactions between such gaze-evoked blinks and gaze shifts in monkeys. Blink probability increases with gaze amplitude and at a faster rate for head-unrestrained movements. Across animals, blink likelihood is inversely correlated with the average gaze velocity of large-amplitude control movements. Gaze-evoked blinks induce robust perturbations in eye velocity. Peak and average velocities are reduced, duration is increased, but accuracy is preserved. The temporal features of the perturbation depend on factors such as the time of blink relative to gaze onset, inherent velocity kinematics of control movements, and perhaps initial eye-in-head position. Although variable across animals, the initial effect is a reduction in eye velocity, followed by a reacceleration that yields two or more peaks in its waveform. Interestingly, head velocity is not attenuated; instead, it peaks slightly later and with a larger magnitude. Gaze latency is slightly reduced on trials with gaze-evoked blinks, although the effect was more variable during head-unrestrained movements; no reduction in head latency is observed. Preliminary data also demonstrate a similar perturbation of gaze-evoked blinks during vertical saccades. The results are compared with previously reported effects of reflexive blinks (evoked by air-puff delivered to one eye or supraorbital nerve stimulation) and discussed in terms of effects of blinks on saccadic suppression, neural correlates of the altered eye velocity signals, and implications on the hypothesis that the attenuation in eye velocity is produced by a head movement command.
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Frontal cortical regions controlling small and large amplitude saccades – A TMS study. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.baga.2011.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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28
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Valls-Sole J. Assessment of excitability in brainstem circuits mediating the blink reflex and the startle reaction. Clin Neurophysiol 2011; 123:13-20. [PMID: 22030138 DOI: 10.1016/j.clinph.2011.04.029] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 04/13/2011] [Accepted: 04/15/2011] [Indexed: 11/18/2022]
Abstract
Excitability is probably the concept that fits better with the definition of the role of neurophysiology in the study of brainstem functions and circuits. Neurophysiological techniques are likely the best suited of all paraclinical tests for documenting the eventual excitability changes that may occur in certain physiological states and in many neurological disorders. The best known test of brainstem excitability is the blink reflex. While a single stimulus can already indicate the readiness of the interneuronal path and the facial motoneurons to fire, pairs of stimuli (conditioning and test) are suited to analyze the degree of excitability recovery after a single discharge. Another brainstem reflex circuit, which excitability testing can be of interest for physiological and clinical exams is the one involved in the startle reaction. The size of the responses and their habituation are the typical measures of excitability of the startle reflex circuit. Prepulse inhibition is a method to modulate both, the blink reflex and the startle reaction. It is defined as the inhibitory effect caused by a stimulus of an intensity low enough not to induce a response by itself on the response elicited by a subsequent stimulus. The circuits of the blink reflex, startle reaction and prepulse inhibition share some commonalities but they are different enough for the three techniques to provide unique, clinically relevant, information in certain conditions. The role of neurophysiology is not limited to testing those functions. It is important also for the assessment of many other circuits, such as those implicated in eye movements, vestibular reflexes, arousal, sleep, breathing, or autonomic reactions, which are not considered in this review.
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Affiliation(s)
- Josep Valls-Sole
- EMG Unit, Neurology Department, Hospital Clinic, University of Barcelona, Spain.
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29
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Bonfiglio L, Sello S, Carboncini MC, Arrighi P, Andre P, Rossi B. Reciprocal dynamics of EEG alpha and delta oscillations during spontaneous blinking at rest: a survey on a default mode-based visuo-spatial awareness. Int J Psychophysiol 2011; 80:44-53. [PMID: 21238505 DOI: 10.1016/j.ijpsycho.2011.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 12/23/2010] [Accepted: 01/10/2011] [Indexed: 11/25/2022]
Abstract
By means of a narrowband wavelet analysis (0.5-6Hz), EEG delta event-related oscillations (EROs), both time- and phase-locked to spontaneous blinking (delta blink-related oscillations or delta BROs), have recently been demonstrated. On the basis of their spatiotemporal characteristics, delta BROs have been proposed as being involved in an automatic mechanism of maintaining awareness in a visuo-spatial context. The aim of the present study was: a) to investigate whether spontaneous blinking was also able to modulate alpha oscillations and, if so, b) whether this modulation was consistent with delta BROs, in order c) to acquire additional information for a better understanding of the cognitive phenomena underlying blinking. Using a broadband (0.5-100 Hz) continuous wavelet transform (CWT), we analysed a total of 189 three-second EEG epochs time-locked to the blinks of seven healthy volunteers. The EEG signals were submitted both to band-pass filtered cross-trial averaging (to obtain frequency-specific BROs) and to alpha event-related synchronization/desynchronization (i.e., blink-related synchronization/desynchronization, BRS/BRD). The alpha oscillations showed: a) an early BRS; b) a BRD in the same temporal window of the delta BROs and, c) a late BRS. We postulate that: a) the early BRS represents the short-term memory maintenance of the last visually perceived trace of the surroundings; b) the alpha BRD is associated with the comparison between the newly perceived image of the environment and its mnestic representation, and, lastly, c) the late BRS is connected with neuronal recovery phenomena.
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Affiliation(s)
- Luca Bonfiglio
- Department of Neurosciences, Unit of Neurorehabilitation, University of Pisa, Via Roma 67, I-56126 Pisa, Italy.
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30
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Infantile-onset saccade initiation delay in a child with a thin intercollicular commissure. Can J Neurol Sci 2010; 37:893-6. [PMID: 20929711 DOI: 10.1017/s0317167100051684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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31
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Abstract
PURPOSE The purpose of this work was to investigate whether individual differences in eye surface area are related to the rate of spontaneous eye blinking (SB) in young infants. Rate of SB was also compared with the rate of gaze shifts. METHODS Forty-four 4-month-old infants were observed under controlled conditions for 4 to 6 min. SB, eye surface area, gaze shifts, and various background variables were measured. RESULTS Individual differences in the rate of SB and in eye surface area were wide. Neither the eye surface area nor the rate of gaze shifting was related to the rate of SB in young infants. However, when SB do occur, they are more likely to coincide with a shift in gaze than immediately precede or follow a shift in gaze. CONCLUSIONS Eye surface area does not explain individual differences in the rate of SB in infancy. This and other recent work suggests that central factors may play a more prominent role in the mechanisms of SB early in human development than previously reported and that the mechanisms regulating the rate of SB seem to be developmentally continuous with those of adults. To the extent that the rate and timing of SB reflects developing neurological systems, SB may be useful clinically.
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32
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Bechara BP, Gandhi NJ. Matching the oculomotor drive during head-restrained and head-unrestrained gaze shifts in monkey. J Neurophysiol 2010; 104:811-28. [PMID: 20505131 PMCID: PMC2934937 DOI: 10.1152/jn.01114.2009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 05/20/2010] [Indexed: 11/22/2022] Open
Abstract
High-frequency burst neurons in the pons provide the eye velocity command (equivalently, the primary oculomotor drive) to the abducens nucleus for generation of the horizontal component of both head-restrained (HR) and head-unrestrained (HU) gaze shifts. We sought to characterize how gaze and its eye-in-head component differ when an "identical" oculomotor drive is used to produce HR and HU movements. To address this objective, the activities of pontine burst neurons were recorded during horizontal HR and HU gaze shifts. The burst profile recorded on each HU trial was compared with the burst waveform of every HR trial obtained for the same neuron. The oculomotor drive was assumed to be comparable for the pair yielding the lowest root-mean-squared error. For matched pairs of HR and HU trials, the peak eye-in-head velocity was substantially smaller in the HU condition, and the reduction was usually greater than the peak head velocity of the HU trial. A time-varying attenuation index, defined as the difference in HR and HU eye velocity waveforms divided by head velocity [alpha = (H(hr) - E(hu))/H] was computed. The index was variable at the onset of the gaze shift, but it settled at values several times greater than 1. The index then decreased gradually during the movement and stabilized at 1 around the end of gaze shift. These results imply that substantial attenuation in eye velocity occurs, at least partially, downstream of the burst neurons. We speculate on the potential roles of burst-tonic neurons in the neural integrator and various cell types in the vestibular nuclei in mediating the attenuation in eye velocity in the presence of head movements.
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Affiliation(s)
- Bernard P Bechara
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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Schultz KP, Williams CR, Busettini C. Macaque pontine omnipause neurons play no direct role in the generation of eye blinks. J Neurophysiol 2010; 103:2255-74. [PMID: 20164389 DOI: 10.1152/jn.01150.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We recorded the activity of pontine omnipause neurons (OPNs) in two macaques during saccadic eye movements and blinks. As previously reported, we found that OPNs fire tonically during fixation and pause about 15 ms before a saccadic eye movement. In contrast, for blinks elicited by air puffs, the OPNs paused <2 ms before the onset of the blink. Thus the burst in the agonist orbicularis oculi motoneurons (OOMNs) and the pause in the antagonist levator palpabrae superioris motoneurons (LPSMNs) necessarily precede the OPN pause. For spontaneous blinks there was no correlation between blink and pause onsets. In addition, the OPN pause continued for 40-60 ms after the time of the maximum downward closing of the eyelids, which occurs around the end of the OOMN burst of firing. LPSMN activity is not responsible for terminating the OPN pause because OPN resumption was very rapid, whereas the resumption of LPSMN firing during the reopening phase is gradual. OPN pause onset does not directly control blink onset, nor does pause offset control or encode the transition between the end of the OOMN firing and the resumption of the LPSMNs. The onset of the blink-related eye transients preceded both blink and OPN pause onsets. Therefore they initiated while the saccadic short-lead burst neurons were still fully inhibited by the OPNs and cannot be saccadic in origin. The abrupt dynamic change of the vertical eye transients from an oscillatory behavior to a single time constant exponential drift predicted the resumption of the OPNs.
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Affiliation(s)
- K P Schultz
- Department of Vision Sciences and Vision Science Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Goossens HHLM, Van Opstal AJ. Differential effects of reflex blinks on saccade perturbations in humans. J Neurophysiol 2010; 103:1685-95. [PMID: 20130041 DOI: 10.1152/jn.00788.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies in both humans and monkeys have indicated that blinks affect the central programming of saccades. In this study, we compared the influence of two types of reflex blinks on the trajectories and kinematics of memory-guided saccades in human subjects. We found that electrical stimulation of the supraorbital nerve shortly before or during a saccade briefly halts or decelerates the eye in midflight. After this short interruption, the eye always resumed its course and reached the target location in the absence of visual feedback. Air puff stimuli produced significant decreases in mean eye velocity too, but in addition to these changes in saccade kinematics, they produced much larger and more variable perturbations of the two-dimensional saccade trajectories. Even so, the endpoints of blink-perturbed saccades obtained under both test conditions remained as accurate and as precise as those observed in the control condition. We hypothesize that the reduction in mean eye velocity is not caused by a trigeminal reactivation of brain stem omnipause neurons but could instead arise from a trigeminal transient inhibition of saccade-related activity in the midbrain superior colliculus (SC). These findings support the theory that blink-perturbed saccades are programmed as slow, but straight, saccades onto which blink-related eye movements are superimposed. This linear superposition occurs downstream from the SC.
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Affiliation(s)
- H H L M Goossens
- Donders Inst. for Brain, Cognition and Behaviour, Dept. of Biophysics, Radboud Univ. Nijmegen Medical Ctr., G. Grooteplein 21, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
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35
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Amiez C, Petrides M. Anatomical organization of the eye fields in the human and non-human primate frontal cortex. Prog Neurobiol 2009; 89:220-30. [DOI: 10.1016/j.pneurobio.2009.07.010] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 06/22/2009] [Accepted: 07/30/2009] [Indexed: 11/24/2022]
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36
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Horn AKE, Büttner-Ennever JA. Brainstem circuits controlling lid-eye coordination in monkey. PROGRESS IN BRAIN RESEARCH 2009; 171:87-95. [PMID: 18718286 DOI: 10.1016/s0079-6123(08)00612-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
In primate, the M-group is a cell cluster in the rostral mesencephalon which contains premotor neurons for the levator palpebrae (LP) and upward-pulling eye muscles. It is therefore thought to play a role in lid-eye coupling during vertical saccades. To further elucidate its role, the afferents to the M-group and LP motoneurons were studied in monkeys. Anterograde tracer injections were placed in one of the three eye-movement-related areas: 1. superior colliculus (SC), 2. interstitial nucleus of Cajal (INC), and 3. the omnipause neuron (OPN) region. Injections into the medial SC subtending upward saccades led to afferent labelling of the ipsilateral M-group and the adjacent rostral interstitial nucleus of the medial longitudinal fascicle (RIMLF), whereas only RIMLF was labelled after an injection into the lateral SC subtending downward saccades. Both RIMLF and M-group received bilateral projections from INC, but only RIMLF received glycineric inputs from the OPN region. This connectivity pattern supports the hypothesis that the M-group mediates lid-eye coupling during vertical upgaze, but is indirectly driven by collaterals of saccadic burst neurons in the RIMLF during lid saccades. A selective projection from the OPN area to the LP motoneurons, but not to other oculomotor neurons is reported here for the first time. The result is supported by the presence of glycinergic terminals only over LP motoneurons, and implies that a subset of OPNs may directly trigger saccade-related blinks.
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Affiliation(s)
- Anja K E Horn
- Institute of Anatomy, Ludwig-Maximilians University of Munich, Pettenkoferstr. 11, Munich, Germany.
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37
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Bonfiglio L, Sello S, Andre P, Carboncini MC, Arrighi P, Rossi B. Blink-related delta oscillations in the resting-state EEG: A wavelet analysis. Neurosci Lett 2009; 449:57-60. [DOI: 10.1016/j.neulet.2008.10.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 10/02/2008] [Accepted: 10/02/2008] [Indexed: 10/21/2022]
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Walton MMG, Bechara B, Gandhi NJ. Effect of reversible inactivation of superior colliculus on head movements. J Neurophysiol 2008; 99:2479-95. [PMID: 18305088 DOI: 10.1152/jn.01112.2007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Because of limitations in the oculomotor range, many gaze shifts must be accomplished using coordinated movements of the eyes and head. Stimulation and recording data have implicated the primate superior colliculus (SC) in the control of these gaze shifts. The precise role of this structure in head movement control, however, is not known. The present study uses reversible inactivation to gain insight into the role of this structure in the control of head movements, including those that accompany gaze shifts and those that occur in the absence of a change in gaze. Forty-five lidocaine injections were made in two monkeys that had been trained on a series of behavioral tasks that dissociate movements of the eyes and head. Reversible inactivation resulted in clear impairments in the animals' ability to perform gaze shifts, manifested by increased reaction times, lower peak velocities, and increased durations. In contrast, comparable effects were not found for head movements (with or without gaze shifts) with the exception of a very small increase in reaction times of head movements associated with gaze shifts. Eye-head coordination was clearly affected by the injections with gaze onset occurring relatively later with respect to head onset. Following the injections, the head contributed slightly more to the gaze shift. These results suggest that head movements (with and without gaze shifts) can be controlled by pathways that do not involve SC.
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Affiliation(s)
- Mark M G Walton
- Department of Otolaryngology, Eye and Ear Institute, University of Pittsburgh, 203 Lothrop Street, Pittsburgh, PA 15213, USA
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Chen B, May PJ. Premotor circuits controlling eyelid movements in conjunction with vertical saccades in the cat: II. interstitial nucleus of Cajal. J Comp Neurol 2007; 500:676-92. [PMID: 17154251 DOI: 10.1002/cne.21203] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Vertical saccadic eye movements are accompanied by concurrent eyelid movements in the same direction. The interstitial nucleus of Cajal (InC) controls eye position for vertical eye movements and may also control saccade-related lid position as well. This study investigates whether the InC serves as a premotor center for eyelid saccades, by employing dual-tracer methods in cats to label both the projections of the InC and the motoneurons supplying the levator palpebrae superioris (LPS) muscle, which lie in the caudal central subdivision (CCS) of the oculomotor complex. Injections of biotinylated dextran amine (BDA) into the InC anterogradely labeled axons that terminated bilaterally throughout the CCS and in the oculomotor nuclei proper. Labeled terminals lay in close association with labeled LPS motoneurons, which were retrogradely labeled following injections of wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) into the muscle. Ultrastructural investigation revealed that most terminals contained spherical vesicles and formed asymmetric synaptic contacts with the labeled motoneurons. These results strongly suggest that the InC monosynaptically controls lid movements in conjunction with vertical eye movements, including saccades. To identify the neurons of origin for this pathway, WGA-HRP injections were centered in the CCS. These experiments indicate that lid and eye motoneurons may share a common source of bilateral InC input. Thus, a common vertical position signal may be employed to maintain the lid and eye at appropriate elevations during fixation, such that the lid sits just above the pupil, allowing unobstructed vision, but at the ready to protect the cornea.
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Affiliation(s)
- Bingzhong Chen
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, Illinois 21201, USA
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40
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Smit AE, Buisseret P, Buisseret-Delmas C, De Zeeuw CI, VanderWerf F, Zerari-Mailly F. Reticulo-collicular and spino-collicular projections involved in eye and eyelid movements during the blink reflex. Neurosci Res 2006; 56:363-71. [PMID: 16973230 DOI: 10.1016/j.neures.2006.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Revised: 07/20/2006] [Accepted: 08/14/2006] [Indexed: 11/15/2022]
Abstract
Reflex blinking provides a useful experimental tool for various functional studies on the peripheral and central nervous system, yet the neuronal circuitry underlying this reflex is not precisely known. In the present study, we investigated as to whether neurons in the reticular formation and rostral cervical spinal cord (C1) may be involved in the blink reflex in rats. To this end we investigated c-Fos expression in these areas following supraorbital nerve stimulation combined with retrograde tracing of gold conjugated horse radish peroxidase (Gold-HRP) from the superior colliculus. We observed many double labeled neurons in the parvocellular reticular nucleus, medullary reticular formation, and laminae IV and V of C1. Thus, these brain regions contain neurons that may be involved in blink reflexes as well as eye movements, because they both can be activated following peri-orbital stimulation and project to the superior colliculus. Consequently, we suggest that the medullary reticular formation and C1 region play a central role in the coordination of eye and eyelid movements during reflex blinking.
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41
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Abstract
The countermanding saccade task has been used in many studies to investigate the neural mechanisms that underlie the decision to execute or restrain rapid eye movements. In this task, the presentation of a saccade target is sometimes followed by the appearance of a stop cue that indicates that the subject should cancel the planned movement. Performance has been modeled as a race between motor preparation and cancellation processes. The signal that reaches its activation threshold first determines whether a saccade is generated or cancelled. In these studies, an important parameter is the time required to process the stop cue, referred to as the stop signal reaction time (SSRT). The SSRT is estimated using statistical approaches, the validity of which has not been unequivocally established. A more direct measure of this parameter might be obtainable if a method was available to "unmask" the developing motor command. This can be accomplished by air-puff-evoked blinks, which inhibit pontine omnipause neurons that serve as an inhibitory gate for the saccadic system. In the present study, brief puffs of air were used to elicit blinks at various times while rhesus monkeys performed a countermanding saccade task. If the developing motor command has not yet been cancelled, this should trigger a saccade. When blinks occurred between approximately 50 and 200 ms after target onset, saccades were often evoked. Saccades were rarely evoked more than approximately 70 ms after stop cue onset; this value represents a behavioral evaluation of SSRT and was comparable to the estimates obtained using standard statistical approaches. When saccades occurred near the SSRT on blink trials, they were often hypometric. Furthermore, Monte Carlo simulations were performed to model the effects of blink time on the race model. Overall, the study supports the validity of the statistical methods currently in use.
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Affiliation(s)
- Mark M G Walton
- Department of Otolaryngology, University of Pittsburgh, Eye and Ear Institute, Pittsburgh, PA 15213, USA
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42
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Abstract
The reticular formation of the brainstem contains functional cell groups that are important for the control of eye, head, or lid movements. The mesencephalic reticular formation is primarily involved in the control of vertical gaze, the paramedian pontine reticular formation in horizontal gaze, and the medullary pontine reticular formation in head movements and gaze holding. In this chapter, the locations, connections, and histochemical properties of the functional cell groups are reviewed and correlated with specific subdivisions of the reticular formation.
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Affiliation(s)
- Anja K E Horn
- Institute of Anatomy, Ludwig-Maximilian University of Munich, Pettenkoferstrasse 11, 80336 Munich, Germany.
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43
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Ziemssen F, Freudenthaler N, Regnery K, Schlote T. Lidschlagaktivität während der Bildschirmarbeit. Ophthalmologe 2005; 102:895-901. [PMID: 15290198 DOI: 10.1007/s00347-004-1072-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New findings based on a noninvasive, automated long-term measurement method revealed interindividual differences in lid movement behavior, existence of blinking patterns, and the dominance of cognitive influence in the regulation of blinking frequency during increased concentration and especially visual attention. The development of an individual blinking animation promises long-lasting increase and harmonization of lid movements during visual display work. Maintenance of the integrity of the ocular surface by preventing surface evaporation and providing sufficient precorneal environment eradicates important pathogenic factors of ocular discomfort. An animation program for stimulation of blinking has been developed. First results showed that an increase in blinking rate initiated by the computer itself is feasible in principle during work at a visual display terminal. Further improvement of this new approach is promising.
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Affiliation(s)
- F Ziemssen
- Abteilung I, Universitätsaugenklinik, Tübingen.
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44
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Rambold H, El Baz I, Helmchen C. Blink effects on ongoing smooth pursuit eye movements in humans. Exp Brain Res 2004; 161:11-26. [PMID: 15480600 DOI: 10.1007/s00221-004-2040-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Accepted: 06/18/2004] [Indexed: 11/30/2022]
Abstract
Blinks are known to affect eye movements, e.g., saccades, slow and fast vergence, and saccade-vergence interaction, in two ways: by superimposition of blink-associated eye movements and changes of the central premotor activity in the brainstem. The goal of this study was to determine, for the first time, the effects of trigeminal evoked blinks on ongoing smooth pursuit eye movements which could be related to visual sensory or premotor neuronal changes. This was compared to the effect of a target disappearing for 100-300 ms duration during ongoing smooth pursuit (blank paradigm) in order to control for the visual sensory effects of a blink. Eye and blink movements were recorded in eight healthy subjects with the scleral search coil technique. Blink-associated eye movements during the first 50% of the blink duration were non-linearly superimposed on the smooth pursuit eye movements. Immediately after the blink-associated eye movements, the pursuit velocity slowly decreased by an average of 3.2+/-2.1 degrees /s. This decrease was not dependent on the stimulus direction. The pursuit velocity decrease caused by blinks which occluded the pupil more than 50% could be explained mostly by blanking the visual target. However, small blinks that did not occlude the pupil (<10% of lid closure) also decreased smooth pursuit velocity. Thus, this blink effect on pursuit velocity cannot be explained by blink-associated eye movements or by the blink having blanked the visual input. We propose that part of this effect might either be caused by incomplete visual suppression during blinks and/or a change in the activity of omnipause neurons.
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Affiliation(s)
- Holger Rambold
- Department of Neurology, University of Luebeck, Ratzeburger Allee 160, 23538 Luebeck, Germany.
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45
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Gandhi NJ, Bonadonna DK. Temporal interactions of air-puff-evoked blinks and saccadic eye movements: insights into motor preparation. J Neurophysiol 2004; 93:1718-29. [PMID: 15469959 PMCID: PMC3641529 DOI: 10.1152/jn.00854.2004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Following the initial, sensory response to stimulus presentation, activity in many saccade-related burst neurons along the oculomotor neuraxis is observed as a gradually increasing low-frequency discharge hypothesized to encode both timing and metrics of the impending eye movement. When the activity reaches an activation threshold level, these cells discharge a high-frequency burst, inhibit the pontine omnipause neurons (OPNs) and trigger a high-velocity eye movement known as saccade. We tested whether early cessation of OPN activity, prior to when it ordinarily pauses, acts to effectively lower the threshold and prematurely trigger a movement of modified metrics and/or dynamics. Relying on the observation that OPN discharge ceases during not only saccades but also blinks, air-puffs were delivered to one eye to evoke blinks as monkeys performed standard oculomotor tasks. We observed a linear relationship between blink and saccade onsets when the blink occurred shortly after the cue to initiate the movement but before the average reaction time. Blinks that preceded and overlapped with the cue increased saccade latency. Blinks evoked during the overlap period of the delayed saccade task, when target location is known but a saccade cannot be initiated for correct performance, failed to trigger saccades prematurely. Furthermore, when saccade and blink execution coincided temporally, the peak velocity of the eye movement was attenuated, and its initial velocity was correlated with its latency. Despite the perturbations, saccade accuracy was maintained across all blink times and task types. Collectively, these results support the notion that temporal features of the low-frequency activity encode aspects of a premotor command and imply that inhibition of OPNs alone is not sufficient to trigger saccades.
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Affiliation(s)
- Neeraj J Gandhi
- Deptartment of Otolaryngology and Center for Neural Basis of Cognition, Eye and Ear Institute, University of Pittsburgh, Rm. 108, 203 Lothrop St., Pittsburgh, PA 15213, USA.
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Williamson SS, Zivotofsky AZ, Basso MA. Modulation of gaze-evoked blinks depends primarily on extraretinal factors. J Neurophysiol 2004; 93:627-32. [PMID: 15342723 DOI: 10.1152/jn.00820.2004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Gaze-evoked blinks are contractions of the orbicularis oculi (OO)-the lid closing muscle-occurring during rapid movements of the head and eyes and result from a common drive to the gaze and blink motor systems. However, blinks occurring during shifts of gaze are often suppressed when the gaze shift is made to an important visual stimulus, suggesting that the visual system can modulate the occurrence of these blinks. In head-stabilized, human subjects, we tested the hypothesis that the presence of a visual stimulus was sufficient, but not necessary, to modulate OO EMG (OOemg) activity during saccadic eye movements. Rapid, reorienting movements of the eyes (saccades) were made to visual targets that remained illuminated (visually guided trials) or were briefly flashed (memory-guided trials) at different amplitudes along the horizontal meridian. We measured OOemg activity and found that the magnitude and probability of OOemg activity occurrence was reduced when a saccade was made to the memory of the spatial location as well as to the actual visual stimulus. The reduced OOemg activity occurred only when the location of the target was previously cued. OOemg activity occurred reliably with spontaneous saccades that were made to locations with no explicit visual stimulus, generally, back to the fixation location. Thus the modulation of gaze-evoked OOemg activity does not depend on the presence of visual information per se, but rather, results from an extraretinal signal.
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Affiliation(s)
- Shawn S Williamson
- Department of Physiology, University of Wisconsin, 1300 University Ave., Rm. 127 SMI, Madison, WI 53706, USA
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Ito J, Nikolaev AR, Luman M, Aukes MF, Nakatani C, van Leeuwen C. Perceptual switching, eye movements, and the bus paradox. Perception 2003; 32:681-98. [PMID: 12892429 DOI: 10.1068/p5052] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
According to a widely cited finding by Ellis and Stark (1978 Perception 7 575-581), the duration of eye fixations is longer at the instant of perceptual reversal of an ambiguous figure than before or after the reversal. However, long fixations are more likely to include samples of an independent random event than are short fixations. This sampling bias would produce the pattern of results also when no correlation exists between fixation duration and perceptual reversals. When an appropriate correction is applied to the measurement of fixation durations, the effect disappears. In fact, there are fewer actual button-presses during the long intervals than would be expected by chance. Moving-window analyses performed on eye-fixation data reveal that no unique eye event is associated with switching behaviour. However, several indicators, such as blink frequency, saccade frequency, and the direction of the saccade, are each differentially sensitive to perceptual and response-related aspects of the switching process. The time course of these indicators depicts switching behaviour as a process of cascaded stages.
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Affiliation(s)
- Junji Ito
- Laboratory for Perceptual Dynamics, Riken BSI, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198 Japan
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VanderWerf F, Brassinga P, Reits D, Aramideh M, Ongerboer de Visser B. Eyelid movements: behavioral studies of blinking in humans under different stimulus conditions. J Neurophysiol 2003; 89:2784-96. [PMID: 12612018 DOI: 10.1152/jn.00557.2002] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The kinematics and neurophysiological aspects of eyelid movements were examined during spontaneous, voluntary, air puff, and electrically induced blinking in healthy human subjects, using the direct magnetic search coil technique simultaneously with electromyographic recording of the orbicularis oculi muscles (OO-EMG). For OO-EMG recordings, surface electrodes were attached to the lower eyelids. To measure the vertical lid displacement, a search coil with a diameter of 3 mm was placed 1 mm from the rim on the upper eyelid on a marked position. Blink registrations were performed from the zero position and from 28 randomly chosen positions. Blinks elicited by electrical stimulation of the supraorbital nerve had shortest duration and were least variable. In contrast, spontaneous blinks had longer duration and greater variability. Blinks induced by air puff had a slightly longer duration and similar variability as electrically induced blinks. There was a correlation between the maximal down phase amplitude and the integrated OO-EMG. Blink duration and maximal down phase amplitude were affected by eye position. Eyes positioned 30 degrees above horizontal displayed the shortest down phase duration and the largest maximal down phase amplitude and velocity. At 30 degrees below horizontal, blinks had the longest total duration, the longest down phase duration, and the lowest maximal down phase amplitude and velocity. The simultaneously recorded integrated OO-EMG was largest in the 30 degrees downward position. In four subjects, the average blinking data showed a linear relation between eye position and OO-EMG, maximal down phase amplitude, and maximal downward velocity.
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Affiliation(s)
- Frans VanderWerf
- Department of Visual System Analysis, Academic Medical Centre, University of Amsterdam, 1105 AZ Amsterdam Zuid-Oost, The Netherlands.
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49
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Abstract
Eye blinking is not only a reflexive action to protect the ocular surface from injury and desiccation; it can also be done intentionally. However, only a few studies have investigated the brain mechanism controlling intentional blinking, and there are still inconsistencies among the reported activation patterns in the human brain evoked by intentional blinking. In monkeys, some areas where blinking is evoked by electrical microstimulation have been found in the premotor areas and in the posterior parietal cortex. But there have been no reports about neuronal activity related to blinking in the cerebral cortex. In the present study, the brain activation evoked by intentional blinking was examined in humans by using fMRI, and the activations were found in the middle precentral gyrus, but not in the posterior parietal cortex, suggesting that the premotor areas, rather than the posterior parietal cortex, are important for controlling intentional blinking.
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Affiliation(s)
- Makoto Kato
- Brain Function Group, Kansai Advanced Research Center, Communications Research Laboratory, Iwaoka 588-2, Nishi-ku, Kobe, Hyogo 651-2492, Japan.
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50
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Kazai K, Yagi A. Comparison between the lambda response of eye-fixation-related potentials and the P100 component of pattern-reversal visual evoked potentials. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2003; 3:46-56. [PMID: 12822598 DOI: 10.3758/cabn.3.1.46] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to compare the lambda response of eye-fixation-related potentials (EFRPs) with the P100 component of pattern-reversal visual-evoked potentials. EFRPs were obtained by averaging EEGs time-locked to the offset of the saccade. The dipole of the lambda response and that of the P100 component were estimated by the dipole-tracing method (Musha & Homma, 1990). The locations of their dipoles at the occipital sites were very close to each other when the difference waveform, which was calculated by subtracting the EFRP to the patternless stimulus from the EFRP to the patterned stimulus, was used for the lambda response. This finding implies that the lambda response and P100 have a common neural generator in the visual cortex. However, the peak latency of the lambda response was shorter than that of P100. The saccades in the EFRP trial were considered to be the cause of the difference.
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Affiliation(s)
- Koji Kazai
- Department of Psychology, Kwansei Gakuin University, Nishinomiya, Hyogo, Japan.
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