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https://www.readbyqxmd.com/read/29142092/response-of-supra-oculomotor-area-neurons-during-combined-saccade-vergence-movements
#1
Adam C Pallus, Mark M G Walton, Michael J Mustari
Combined saccade-vergence movements allow humans and other primates to align their eyes with objects of interest in three-dimensions. In the absence of saccades, vergence movements are typically slow, symmetrical movements of the two eyes in opposite directions. However, combined saccade-vergence movements produce vergence velocities that exceed values observed during vergence alone. This phenomenon is often called "vergence enhancement", or "saccade-facilitated vergence," though it is important to consider that rapid vergence changes, known as "vergence transients," are also observed during conjugate saccades...
November 15, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29141478/utility-of-quick-oculomotor-tests-for-screening-the-vestibular-system-in-the-subacute-and-chronic-populations
#2
Helen S Cohen, Jasmine Stitz, Haleh Sangi-Haghpeykar, Susan P Williams, Ajitkumar P Mulavara, Brian T Peters, Jacob J Bloomberg
OBJECTIVE: The goal of this study was to determine the sensitivity and specificity of some widely used, easily administered clinical tests. BACKGROUND: Simple tests of oculomotor function have become widely used for clinical screening of patients suspected of having vestibular disorders despite a paucity of evidence showing good statistical support for their use in this highly variable population. METHODS: Healthy controls with no history of otologic or neurologic disorders (n = 291) were compared to patients with known vestibular disorders (n = 62)...
November 16, 2017: Acta Oto-laryngologica
https://www.readbyqxmd.com/read/29141275/roles-of-the-declive-folium-and-tuber-cerebellar-vermian-lobules-in-sportspeople
#3
In Sung Park, Nam Joon Lee, Im Joo Rhyu
The cerebellum plays vital roles in balance control and motor learning, including in saccadic adaptation and coordination. It consists of the vermis and two hemispheres and is anatomically separated into ten lobules that are designated as I-X. Although neuroimaging and clinical studies suggest that functions are compartmentalized within the cerebellum, the function of each cerebellar lobule is not fully understood. Electrophysiological and lesion studies in animals as well as neuroimaging and lesion studies in humans have revealed that vermian lobules VI and VII (declive, folium, and tuber) are critical for controlling postural balance, saccadic eye movements, and coordination...
September 28, 2017: Journal of Clinical Neurology
https://www.readbyqxmd.com/read/29133438/normal-topography-and-binocularity-of-the-superior-colliculus-in-strabismus
#4
John R Economides, Brittany C Rapone, Daniel L Adams, Jonathan C Horton
In subjects with alternating strabismus either eye can be used to saccade to visual targets. The brain must calculate the correct vector for each saccade, which will depend on the eye chosen to make it. The superior colliculus, a major midbrain center for saccade generation, was examined to determine if the maps serving each eye were shifted to compensate for strabismus.Alternating exotropia was induced in two male macaques at age one month by sectioning the tendons of the medial recti. Once the animals grew to maturity, they were trained to fixate targets with either eye...
November 13, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29133433/attention-priority-map-of-face-images-in-human-early-visual-cortex
#5
Ce Mo, Dongjun He, Fang Fang
Attention priority maps are topographic representations that are utilized for attention selection and guidance of task-related behavior during visual processing. Previous studies have identified attention priority maps of simple artificial stimuli in multiple cortical and subcortical areas, while investigating neural correlates of priority maps of natural stimuli is complicated by the complexity of their spatial structure and the difficulty of behaviorally characterizing their priority map. To overcome these challenges, we reconstructed the topographic representations of upright/invered face images from fMRI BOLD signals in human early visual areas V1-V3 based on a voxel-wise population receptive field model and behaviorally characterized the priority map as the first saccadic eye movement pattern when subjects performed a face matching task, relative to the condition in which subjects performed a phase-scrambled face matching task...
November 13, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29132360/neoanalysis-a-python-based-toolbox-for-quick-electrophysiological-data-processing-and-analysis
#6
Bo Zhang, Ji Dai, Tao Zhang
BACKGROUND: In a typical electrophysiological experiment, especially one that includes studying animal behavior, the data collected normally contain spikes, local field potentials, behavioral responses and other associated data. In order to obtain informative results, the data must be analyzed simultaneously with the experimental settings. However, most open-source toolboxes currently available for data analysis were developed to handle only a portion of the data and did not take into account the sorting of experimental conditions...
November 13, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/29129730/how-post-saccadic-target-blanking-affects-the-detection-of-stimulus-displacements-across-saccades
#7
David E Irwin, Maria M Robinson
When a visual stimulus is displaced during a saccade the displacement is often not noticed unless it is large compared to the amplitude of the eye movement. Displacement detection is improved, however, if a blank intervenes between saccade target offset and the presentation of the displaced post-saccadic stimulus. This has been interpreted as evidence that precise information about eye position and accurate memory for the position of the pre-saccadic target are available immediately after saccade offset, but are overridden by the presence of the post-saccadic stimulus if it is present when the eyes land...
November 9, 2017: Vision Research
https://www.readbyqxmd.com/read/29129037/eye-movement-abnormalities-in-middle-cerebellar-peduncle-strokes
#8
Sung-Hee Kim, Ji-Soo Kim
The middle cerebellar peduncle (MCP) is a major conduit for cortico-ponto-cerebellar fibers that convey information related to eye movements. This study aims to elucidate eye movement abnormalities that arise from lesions confined to the MCP. In 23 patients with acute strokes restricted to unilateral MCPs, we investigated the clinical features and ocular motor findings including spontaneous nystagmus, saccades, smooth pursuit, ocular tilt reaction, and head impulse tests. Bithermal caloric tests and audiometry were also performed...
November 11, 2017: Acta Neurologica Belgica
https://www.readbyqxmd.com/read/29127718/-frontal-eye-field-in-prosimian-galagos-intracortical-microstimulation-and-tracing-studies
#9
Iwona Stepniewska, Pierre Pouget, Jon H Kaas
The frontal eye field (FEF) in prosimian primates was identified as a small cortical region, above and anterior to the anterior frontal sulcus, from which saccadic eye movements were evoked with electrical stimulation. Tracer injections revealed FEF connections with cortical and subcortical structures participating in higher order visual processing. Ipsilateral cortical connections were the densest with adjoining parts of the dorsal premotor and prefrontal cortex (PFC). Label in a region corresponding to supplementary eye field (SEF) of other primates, suggests the existence of SEF in galagos...
November 11, 2017: Journal of Comparative Neurology
https://www.readbyqxmd.com/read/29127364/comparing-ataxias-with-oculomotor-apraxia-a-multimodal-study-of-aoa1-aoa2-and-at-focusing-on-video-oculography-and-alpha-fetoprotein
#10
L L Mariani, S Rivaud-Péchoux, P Charles, C Ewenczyk, A Meneret, B B Monga, M-C Fleury, E Hainque, T Maisonobe, B Degos, A Echaniz-Laguna, M Renaud, T Wirth, D Grabli, A Brice, M Vidailhet, D Stoppa-Lyonnet, C Dubois-d'Enghien, I Le Ber, M Koenig, E Roze, C Tranchant, A Durr, B Gaymard, M Anheim
Whether the recessive ataxias, Ataxia with oculomotor apraxia type 1 (AOA1) and 2 (AOA2) and Ataxia telangiectasia (AT), can be distinguished by video-oculography and alpha-fetoprotein level remains unknown. We compared 40 patients with AOA1, AOA2 and AT, consecutively referred between 2008 and 2015 with 17 healthy subjects. Video-oculography revealed constant impairments in patients such as cerebellar signs, altered fixation, impaired pursuit, hypometric saccades and abnormal antisaccades. Horizontal saccade latencies could be highly increased reflecting oculomotor apraxia in one third of patients...
November 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29124096/implicit-theory-of-mind-across-the-life-span-anticipatory-looking-data
#11
Louisa Kulke, Mirjam Reiß, Horst Krist, Hannes Rakoczy
In this work, we present a collection of data from three replication studies of anticipatory looking false belief tasks measuring implicit Theory of Mind. Two paradigms, by Southgate & Senju and Surian & Geraci were replicated in two independent labs. Eye-tracking data was collected and processed in line with the original procedures to allow for an investigation of effects of false belief processing on looking times and first saccades.
December 2017: Data in Brief
https://www.readbyqxmd.com/read/29121855/saccade-adaptation-deficits-in-developmental-dyslexia-suggest-disruption-of-cerebellar-dependent-learning
#12
Edward G Freedman, Sophie Molholm, Michael J Gray, Daniel Belyusar, John J Foxe
BACKGROUND: Estimates of the prevalence of developmental dyslexia in the general population range from 5% to as many as 10%. Symptoms include reading, writing, and language deficits, but the severity and mix of symptoms can vary widely across individuals. In at least some people with dyslexia, the structure and function of the cerebellum may be disordered. Saccadic adaptation requires proper function of the cerebellum and brainstem circuitry and might provide a simple, noninvasive assay for early identification and sub-phenotyping in populations of children who may have dyslexia...
November 9, 2017: Journal of Neurodevelopmental Disorders
https://www.readbyqxmd.com/read/29121544/brain-volumetric-analysis-and-cortical-thickness-in-adults-with-saccadic-intrusions-ocular-flutter-or-opsoclonus-myoclonus-syndrome
#13
María-José Ibáñez-Juliá, Evangelia Pappa, Bertrand Gaymard, Delphine Leclercq, Charlotte Hautefort, Caroline Tilikete, Jean-Yves Delattre, Khê Hoang-Xuan, Dimitri Psimaras, Agusti Alentorn
OBJECTIVES: Ocular flutter (OF) and opsoclonus are considered a continuum with a similar pathogenesis. Due to the rarity of this disease in the adult population, little is known about the brain morphological changes in the chronic phase of the disease. PATIENTS AND METHODS: Six magnetic resonance imaging from adults with previous history of OF/Opsoclonus and 12 healthy patients (paired by age and sex) were analyzed in order to identify the long term cortical thickness pattern in this rare disease by using Freesurfer...
October 31, 2017: Clinical Neurology and Neurosurgery
https://www.readbyqxmd.com/read/29118197/control-of-saccadic-latency-in-a-dynamic-environment-allocation-of-saccades-in-time-follows-the-matching-law
#14
Cécile Vullings, Laurent Madelain
When exploring the visual environment, one uses saccades to shift gaze and fixation to gather spatially and temporally localized information. We propose that the temporal structure of our environment should constrain the temporal allocation of saccades. Here, we probe the possibility of learning to control saccadic latencies in a choice paradigm. Six participants made saccades within 80-300ms following a target horizontally stepping by 10 deg between two fixed locations. For each participant we constructed two classes of latencies, "short" and "long", using the first and last quartiles of the individual baseline distribution (e...
November 8, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29117005/coordination-of-gaze-behavior-and-foot-placement-during-walking-in-persons-with-glaucoma
#15
Andreas B Miller, Kim Lajoie, Robert A Strath, David R Neima, Daniel S Marigold
PURPOSE: Vision normally provides environmental information necessary to direct the foot to safe locations during walking. Peripheral visual field loss limits what a person can see, and may alter how a person visually samples the environment. Here we tested the hypothesis that the spatial-temporal coupling between gaze and stepping in a precision-based walking task is altered in persons with glaucoma, particularly under dual task situations, and results in reduced foot-placement accuracy...
November 7, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/29116867/the-effects-of-smoking-abstinence-on-incentivized-spatial-working-memory
#16
Charles Geier, Nicole Roberts, David Lydon-Staley
BACKGROUND AND OBJECTIVE: Reward processing and working memory (WM) underlie value-based decision-making; consequently, joint examination of these systems may further our understanding of why smokers choose to smoke again following a quit attempt (relapse). While previous studies have demonstrated altered reward and WM function associated with nicotine exposure, little is known about the effects of abstinence on the joint function of these systems. The current study aims to address this gap...
November 8, 2017: Substance Use & Misuse
https://www.readbyqxmd.com/read/29114840/fixational-saccades-and-their-relation-to-fixation-instability-in-strabismic-monkeys
#17
COMPARATIVE STUDY
Suraj Upadhyaya, Mythri Pullela, Santoshi Ramachandran, Samuel Adade, Anand C Joshi, Vallabh E Das
Purpose: To evaluate the contribution of fixational saccades toward fixation instability in strabismic monkeys. Methods: Binocular eye movements were measured as six experimental monkeys (five strabismic monkeys and one monkey with downbeat nystagmus) and one normal monkey fixated targets of two shapes (Optotype, Disk) and two sizes (0.5°, 2°) during monocular and binocular viewing. Fixational saccades were detected using an unsupervised clustering algorithm. Results: When compared with the normal monkey, amplitude and frequency of fixational saccades in both the viewing and nonviewing eye were greater in 3 of 5 strabismic monkeys (1-way ANOVA on ranks P < 0...
November 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/29111439/the-effect-of-different-brightness-conditions-on-visually-and-memory-guided-saccades
#18
Anna-Maria Felßberg, Isabel Dombrowe
It is commonly assumed that saccades in the dark are slower than saccades in a lit room. Early studies that investigated this issue using electrooculography (EOG) often compared memory guided saccades in darkness to visually guided saccades in an illuminated room. However, later studies showed that memory guided saccades are generally slower than visually guided saccades. Research on this topic is further complicated by the fact that the different existing eyetracking methods do not necessarily lead to consistent measurements...
October 27, 2017: Vision Research
https://www.readbyqxmd.com/read/29110566/predicting-the-outcome-after-acute-unilateral-vestibulopathy-analysis-of-vestibulo-ocular-reflex-gain-and-catch-up-saccades
#19
Niccolò Cerchiai, Elena Navari, Stefano Sellari-Franceschini, Chiara Re, Augusto Pietro Casani
Objectives (1) To describe the relationships among the main instrumental features characterizing an acute unilateral vestibulopathy and (2) to clarify the role of the video head impulse test in predicting the development of chronic vestibular insufficiency. Study Design Case series with chart review. Setting Tertiary referral center. Subjects and Methods Sixty patients suffering from acute unilateral vestibulopathy were retrospectively analyzed: 30 who recovered spontaneously (group 1) and 30 who needed a vestibular rehabilitation program (group 2)...
November 1, 2017: Otolaryngology—Head and Neck Surgery
https://www.readbyqxmd.com/read/29109905/abnormalities-of-eye-hand-coordination-in-patients-with-writer-s-cramp-possible-role-of-the-cerebellum
#20
Ketan Jhunjhunwala, Raviteja Kotikalapudi, Abhishek Lenka, Kandavel Thennarassu, Ravi Yadav, Jitender Saini, Pramod Kumar Pal
Background: Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of WC has not been fully understood. The role of the cerebellum has been increasingly recognized in the pathogenesis of dystonia. As the cerebellum is crucial for maintaining accurate eye-hand coordination (EHC), its role in the pathogenesis of WC can be investigated by studying the EHC in patients with WC. Methods: Fifteen patients with WC (women:men, 3:12) and 15 age- and gender-matched controls performed oculomotor and EHC tasks...
2017: Tremor and Other Hyperkinetic Movements
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