In a three-dimensional (3D) world most saccades are made towards visual targets that are located at different distances. We previously demonstrated that gaze shifts within 3D space consist of two stages: a target saccade followed by a corrective saccade during gaze fixation that directs the eyes to the physical target location. We proposed that, by accurately positioning the eyes on the visual object, the visual system maintains an orderly representation of the visual world. In this study we used a double saccade experiment to assess the function of corrective saccades in humans. We found that, when a corrective eye movement occurred during fixation on the first target point, the direction of the second saccade towards the next target point was accurate. When a corrective saccade was absent, a directional error of the second target saccade was observed. This finding, which cannot be explained by current models of eye movement control, supports the idea of a two-step model in saccade programming. We suggest that the motor system sends a corollary discharge when programming a corrective saccade for maintaining an orderly representation of the visual world. In conclusion, our results indicate that corrective saccades have a role in programming target saccades within 3D space.
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http://dx.doi.org/10.1111/ejn.12777 | DOI Listing |
Exp Brain Res
January 2025
Department of Neurology and Suzhou Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, No. 1055, Sanxiang Road, Suzhou, 215004, Jiangsu Province, People's Republic of China.
This study investigated the relationship between eye movement parameters and cognitive function in patients with mild to moderate Alzheimer's disease (AD). A total of 80 patients with AD (mild and moderate) and 34 normal controls (NC) participated. Neuropsychological assessments were conducted using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), while eye movements were recorded using eye-tracking technology.
View Article and Find Full Text PDFFront Neurol
December 2024
Institut de Recherche Oto-Neurologique (IRON), Paris, France.
Introduction: While most head movements in daily life are active, most tools used to assess vestibular deficits rely on passive head movements. A single gain value is not sufficient to quantify gaze stabilization efficiency during active movements in vestibular deficit patients. Moreover, during active gaze shifts, anticipatory mechanisms come into play.
View Article and Find Full Text PDFJ Neuroophthalmol
December 2024
Exploration de la Vision et Neuro-Ophtalmologie (RF, VS), CHU de Lille, Lille, France; and University of Lille (QL, VS, MB), INSERM, CNRS, UMR-S 1172-Lab, Lille Neuroscience & Cognition, Lille, France.
Background: Most of the data on visual functions in Leber hereditary optic neuropathy (LHON) is based on patient questionnaires. Our study assessed the impact of LHON on visual function by testing facial recognition and execution of purposeful actions.
Methods: Twelve participants with LHON with central scotoma ranging from 5° to 20° and 12 unaffected age-matched controls were involved in our study.
Ear Hear
December 2024
Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, USA.
Objectives: This study aimed to determine if the presence of corrective saccades during video head impulse test (vHIT) stimulation of the bilateral posterior semicircular canals (PSCs) correlated with other vestibular test results, demographics, symptoms, or diagnoses.
Design: This study was a retrospective chart review where 1006 subjects' vHIT records were screened with 17 subjects meeting inclusion criteria for isolated bilateral PSC saccades.
Results: Of the 1006 patients undergoing vHIT testing, only 1.
Isr Med Assoc J
December 2024
Department of Dermatology, Emek Medical Center, Afula, Israel.
Background: Little is known about audiovestibular function in psoriasis, a chronic systemic inflammatory disease that affects 2% of the world's population.
Objectives: To investigate audiovestibular function in patients with psoriasis.
Methods: In this prospective case-control trial, we enrolled 33 patients with psoriasis and 30 healthy controls.
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