The visuotopic structure of primary visual cortex was studied in a group of 7 human volunteers using positron emission transaxial tomography (PETT) and 18F-labeled 2-deoxy-2-fluoro-D-glucose ( [18F]DG). A computer animation was constructed with a spatial structure which was matched to estimates of human cortical magnification factor and to striate cortex stimulus preferences. A lateralized cortical 'checker-board' pattern of [18F]DG was stimulated in primary visual cortex by having subjects view this computer animation following i.v. injection of [18F]DG. The spatial structure of the stimulus was designed to produce an easily recognizable 'signature' in a series of 9 serial PETT scans obtained from each of a group of 7 volunteers. The predicted lateralized topographic 'signature' was observed in 6 of 7 subjects. Applications of this method for further PETT studies of human visual cortex are discussed.
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http://dx.doi.org/10.1016/0006-8993(84)91033-3 | DOI Listing |
Audiol Res
January 2025
Neurology Department, Kafrelsheikh University Hospitals, Kafr Elsheikh 33516, Egypt.
Unlabelled: Peripheral hearing loss is associated with the cross-modal re-organization of the auditory cortex, which can occur in both pre- and post-lingual deaf cases.
Background/objectives: Whether to rely on the visual cues in cases with severe hearing loss with adequate amplification is a matter of debate. So, this study aims to study visual evoked potentials (VEPs) in children with severe or profound HL, whether fitted with HAs or CIs.
Front Aging Neurosci
January 2025
Department of Rehabilitation Medicine Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
Background: The perception of Subjective Visual Vertical (SVV) is crucial for postural orientation and significantly reflects an individual's postural control ability, relying on vestibular, visual, and somatic sensory inputs to assess the Earth's gravity line. The neural mechanisms and aging effects on SVV perception, however, remain unclear.
Objective: This study seeks to examine aging-related changes in SVV perception and uncover its neurological underpinnings through functional near-infrared spectroscopy (fNIRS).
Neurosurg Focus Video
January 2025
Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and.
Eloquent brain creates a challenge when resecting brain arteriovenous malformations (bAVMs). Here the authors present their technique of using subcortical motor mapping as an adjunct to increase safety during resection of a high-grade bAVM involving somatosensory cortex as well as cortical spinal tracts and visual tracts. After a bilateral craniotomy, they use direct cortical stimulation of the left motor cortex and subcortical stimulation using a suction stimulator to dynamically map motor tracts during the resection.
View Article and Find Full Text PDFNeurosurg Focus Video
January 2025
Department of Neurosurgery.
Surgically remediable epilepsy of the eloquent brain poses the added challenge of preserving function while curing disease. Long-standing epileptogenic lesions have tenacious seizure networks and significant functional reorganizations. Large multilobar lesions may involve multiple functional areas, thereby challenging the limits of functional brain mapping.
View Article and Find Full Text PDFFront Neurosci
January 2025
Vision and Neural Engineering Laboratory, Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States.
Introduction: The vergence neural system was stimulated to dissect the afferent and efferent components of symmetrical vergence eye movement step responses. The hypothesis tested was whether the afferent regions of interest would differ from the efferent regions to serve as comparative data for future clinical patient population studies.
Methods: Thirty binocularly normal participants participated in an oculomotor symmetrical vergence step block task within a functional MRI experiment compared to a similar sensory task where the participants did not elicit vergence eye movements.
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