Eye movements of the human fetus were detected in utero by means of real-time B-scan and M-mode ultrasonography. In 14 low-risk fetuses studied between 32 weeks menstrual age and term either rapid or slow eye movements or a mixture of both types were detected in 60 +/- 10% (mean +/- SD) of 558 2 min scoring epochs. A comparison of direct echoscopic detection of eye movements in a 3-day-old neonate confirmed that the movements observed in the orbital region with the real-time scanner corresponded well with eye movements seen directly. Thus eye movements can be added to the list of phenomena which can be observed noninvasively for the study of human fetal behaviour.
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http://dx.doi.org/10.1016/0378-3782(81)90074-8 | DOI Listing |
J Vis
January 2025
Vision and Control of Action (VISCA) Group, Department of Cognition, Development and Psychology of Education, Institut de Neurociències, Universitat de Barcelona, Barcelona, Catalonia, Spain.
The characterization of how precisely we perceive visual speed has traditionally relied on psychophysical judgments in discrimination tasks. Such tasks are often considered laborious and susceptible to biases, particularly without the involvement of highly trained participants. Additionally, thresholds for motion-in-depth perception are frequently reported as higher compared to lateral motion, a discrepancy that contrasts with everyday visuomotor tasks.
View Article and Find Full Text PDFAtten Percept Psychophys
January 2025
U.S. DEVCOM Army Research Laboratory, Humans in Complex Systems, Aberdeen Proving Ground, MD, USA.
Historically, electrophysiological correlates of scene processing have been studied with experiments using static stimuli presented for discrete timescales where participants maintain a fixed eye position. Gaps remain in generalizing these findings to real-world conditions where eye movements are made to select new visual information and where the environment remains stable but changes with our position and orientation in space, driving dynamic visual stimulation. Co-recording of eye movements and electroencephalography (EEG) is an approach to leverage fixations as time-locking events in the EEG recording under free-viewing conditions to create fixation-related potentials (FRPs), providing a neural snapshot in which to study visual processing under naturalistic conditions.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Department of Ophthalmology, University of California, Los Angeles, California, United States.
Purpose: The optic nerve (ON) is mechanically perturbed by eye movements that shift cerebrospinal fluid (CSF) within its surrounding dural sheath. This study compared changes in ON length and CSF volume within the intraorbital ON sheath caused by eye movements in healthy subjects and patients with optic neuropathies.
Methods: Twenty-one healthy controls were compared with 11 patients having primary open angle glaucoma (POAG) at normal intraocular pressure (IOP), and 11 with chronic non-arteritic anterior ischemic optic neuropathy (NA-AION).
A 64-year-old woman suffered a traumatic rupture of the inferior rectus muscle, with the distal segment unrecoverable. An inferior oblique muscle transposition, augmented with a posterior fixation suture, was performed. This modification may have contributed to the surgical outcome.
View Article and Find Full Text PDFVision (Basel)
January 2025
Centre Gilles Gaston Granger, UMR 7304 Centre National de la Recherche Scientifique, Aix Marseille Université, 13621 Aix-en-Provence, France.
The appearance of an object triggers an orienting gaze movement toward its location. The movement consists of a rapid rotation of the eyes, the saccade, which is accompanied by a head rotation if the target eccentricity exceeds the oculomotor range and by a slow eye movement if the target moves. Completing a previous report, we explain the numerous points that lead to questioning the validity of a one-to-one correspondence relation between measured physical values of gaze or head orientation and neuronal activity.
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