Background/objectives: Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing.
Method: High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes.
Results: There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing.
Conclusions: The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.
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http://dx.doi.org/10.1080/13803395.2017.1332169 | DOI Listing |
Psych J
January 2025
Department of Psychology, Suzhou University of Science and Technology, Suzhou, China.
Visual attention is intrinsically rhythmic and oscillates based on the discrete sampling of either single or multiple objects. Recently, studies have found that the early visual cortex (V1/V2) modulates attentional rhythms. Both monocular and binocular cells are present in the early visual cortex, which acts as a transfer station for transformation of the monocular visual pathway into the binocular visual pathway.
View Article and Find Full Text PDFStrabismus
January 2025
School of Optometry and Vision Science, University of Cape Coast, Cape Coast, Ghana.
The study sought to compare the number of cycles (NOS) for the first and second thirty-seconds (FASTS) within 1 min of accommodative facility (AF) and vergence facility (VF) testing to explore possibilities of reducing testing time to 30 s. In this cross-sectional study, a multistage sample of school children (aged 8-17 years) was taken through ocular-visual screening. Eligible participants (586) underwent refraction, stereo-acuity measurement, AF testing using ± 2D lens flippers, and VF testing using 3 BI/12 BO flipper prisms.
View Article and Find Full Text PDFRadiol Case Rep
March 2025
Phoenix Children's Hospital, Department of Radiology, 1919 E Thomas Rd, Phoenix, AZ 85016, USA.
Wyburn-Mason disease (WMD) is a rare congenital phakomatosis known for its complex arteriovenous malformations (AVMs) predominantly affecting the brain and ocular structures. We present the case of a 19-year-old female with an unruptured Spetzler-Martin grade 5 left thalamic AVM, who initially exhibited progressive visual impairment and migraines. Following diagnosis, she was treated with trametinib, a MEK inhibitor; however, nine months later, she developed acute complications, including left monocular blindness and right hemisensory loss.
View Article and Find Full Text PDFCureus
November 2024
Radiodiagnosis, MNR Medical College and Hospital, Sangareddy, IND.
Lymphangiomas are localized multi-cystic malformations of the lymphatic and vascular system, primarily affecting the head and neck regions in children. Orbital lymphangiomas are not considered hamartomas because the orbit does not commonly display lymphatic vessels. In this case report, we describe a male patient who was 15 years old and presented to our medical facility with the primary complaints of having a bulging left eye, sudden chemosis of the lower conjunctiva, and pain in the left eye.
View Article and Find Full Text PDFOcul Immunol Inflamm
December 2024
Harvard Retinal Imaging Lab, Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA.
Purpose: To describe a case of early-stage Extensive Macular Atrophy with Pseudodrusen-like appearance (EMAP) presenting with acute monocular loss and atypical retinal lesions suggestive of posterior uveitis.
Methods: Case report with longitudinal follow-up including visual field testing and multimodal imaging.
Results: A 53-year-old woman presented with sudden vision loss in her right eye (RE).
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