Read by QxMD icon Read

Left Visual Field

E V Aleksandrova, A I Batalov, E L Pogosbekyan, N E Zakharova, L M Fadeeva, A D Kravchuk, I N Pronin, A A Potapov
The study purpose was to develop a technique for intravital visualization of the brainstem reticular formation fibers in healthy volunteers using magnetic resonance imaging (MRI). MATERIAL AND METHODS: The study included 21 subjects (13 males and 8 females) aged 21 to 62 years. The study was performed on a magnetic resonance imaging scanner with a magnetic field strength of 3 T in T1, T2, T2-FLAIR, DWI, and SWI modes. A CSD-HARDI algorithm was used to identify thin intersecting fibers of the reticular formatio...
2018: Zhurnal Voprosy Neĭrokhirurgii Imeni N. N. Burdenko
Mirna Pineda-Ortíz, Gustavo Pacheco-López, Moisés Rubio-Osornio, Carmen Rubio, Juan Valadez-Rodríguez
RATIONALE: Visual therapy, which includes a restorative and compensatory approach, seems to be a viable treatment option for homonymous defects of the visual field in patients with postgeniculate injury of the visual pathway, due to occipital arteriovenous malformation (AVM). Until now, the Mexican population suffering from homonymous hemianopia did not have health services that provided any type of visual therapy for their condition. PATIENT CONCERNS: A 31-year-old patient, who underwent a surgical procedure for resection of the AVM, was referred with posterior low vision on the left side...
March 2018: Medicine (Baltimore)
Shinya Higuchi, Iwao Matsunaga, Kiyokazu Koga, Eiichi Teshima, Atsuhiro Nakashima, Ryuji Tominaga, Tsuyoshi Ito
In almost every type of artificial valve, structural failure has been described. We are reporting on a case of a sudden leaflet escape of an Edwards TEKNA mitral valve prosthesis 12 years after implantation. The patient had a sudden onset of dyspnea and severe pulmonary edema with subsequent cardiogenic shock. An emergency mitral replacement was successfully performed. A multi-detector computed tomography scanning and three-dimensional imaging showed two fragments that had embolized in the terminal aorta and the left common iliac artery...
March 13, 2018: General Thoracic and Cardiovascular Surgery
Valerio Santangelo
Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets...
2018: Frontiers in Integrative Neuroscience
Eline R Kupers, Helena X Wang, Kaoru Amano, Kendrick N Kay, David J Heeger, Jonathan Winawer
Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI) and subthreshold neuronal synchrony (oscillations and event-related potentials). In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG)-have recently measured broadband power elevation in field potentials (~50-200 Hz) as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG)...
2018: PloS One
Mengyang He, Changzhu Qi, Yang Lu, Amanda Song, Saba Z Hayat, Xia Xu
Extensive studies have shown that a sports expert is superior to a sports novice in visually perceptual-cognitive processes of sports scene information, however the attentional and neural basis of it has not been thoroughly explored. The present study examined whether a sport expert has the attentional superiority on scene information relevant to his/her sport skill, and explored what factor drives this superiority. To address this problem, EEGs were recorded as participants passively viewed sport scenes (tennis vs...
March 7, 2018: Neuroscience
Alexia Roux-Sibilon, Solène Kalénine, Cédric Pichat, Carole Peyrin
Visual extinction, a parietal syndrome in which patients exhibit perceptual impairments when two objects are simultaneously presented in the visual field, is reduced when objects are correctly positioned for action, indicating that action helps patients' visual attention. Similarly, healthy individuals make faster action decisions on object pairs that appear in left/right standard co-location for actions in comparison to object pairs that appear in a mirror location, a phenomenon called the paired-object affordance effect...
March 6, 2018: Neuropsychologia
Li Zhaoping, Joëlle Ackermann
In a random-dot stereogram, the percept of object surfaces in a three-dimensional scene is generated by images presented to left and right eyes that comprise interocularly corresponding random black and white dots. The spatial disparities between the corresponding dots determine the depths of object surfaces. If the dots are anticorrelated, such that a black dot in one monocular image corresponds to a white dot in the other, disparity-tuned neurons in the primary visual cortex (V1) respond as if their preferred disparities become nonpreferred and vice versa, thereby reversing the disparity signs reported to higher visual areas...
January 1, 2018: Perception
Dimitrios Karagiannis, George Kontadakis, Dimitrios Brouzas, Marilita Moschos, Alexandros Damanakis
Purpose: To describe a case of a child with nonorganic visual loss due to school bullying. Observations: An eight-year-old boy presented with bilateral painless vision loss for a few days. His best corrected visual acuity (BCVA) was 20/200 in the right eye and 20/140 in the left eye. Color vision was normal. Fundoscopy, visual fields, electroretinography, electrooculography and visual evoked potentials were within normal limits. A nonorganic (psychogenic) cause of visual loss was suspected...
April 2017: American Journal of Ophthalmology Case Reports
Yusuke Kameda, Akira Hirose, Tomohiro Iida, Yasuko Uchigata, Shigehiko Kitano
Purpose: To report a case of a giant retinal pigment epithelial (RPE) tear associated with fluid overload in a patient with diabetic macular edema (DME) and kidney disease. Observations: A 60-year-old man with type 2 diabetes mellitus and end-stage diabetic kidney disease who had gained weight because of fluid overload complained of a visual disturbance in the left eye that had started a few days earlier. The left fundus showed a RPE defect in two temporal quadrants under an extensive serous retinal detachment (SRD) with exacerbation of the original DME...
April 2017: American Journal of Ophthalmology Case Reports
Crawford I P Winlove, Fraser Milton, Jake Ranson, Jon Fulford, Matthew MacKisack, Fiona Macpherson, Adam Zeman
Visual imagery is a form of sensory imagination, involving subjective experiences typically described as similar to perception, but which occur in the absence of corresponding external stimuli. We used the Activation Likelihood Estimation algorithm (ALE) to identify regions consistently activated by visual imagery across 40 neuroimaging studies, the first such meta-analysis. We also employed a recently developed multi-modal parcellation of the human brain to attribute stereotactic co-ordinates to one of 180 anatomical regions, the first time this approach has been combined with the ALE algorithm...
January 2, 2018: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Joshua Snell, Sebastiaan Mathôt, Jonathan Mirault, Jonathan Grainger
There are roughly two lines of theory to account for recent evidence that word processing is influenced by adjacent orthographic information. One line assumes that multiple words can be processed simultaneously through a parallel graded distribution of visuo-spatial attention. The other line assumes that attention is strictly directed to single words, but that letter detectors are connected to both foveal and parafoveal feature detectors, as such driving parafoveal-foveal integrative effects. Putting these two accounts to the test, we build on recent research showing that the pupil responds to the brightness of covertly attended (i...
February 27, 2018: Scientific Reports
Sung Ho Jang, Woo Hyuk Jang
RATIONALE: We report on a patient who developed allocentric neglect due to injury of the inferior fronto-occipital fasciculus (IFOF) following intracranial hemorrhage, diagnosed using diffusion tensor tractography (DTT). PATIENT CONCERNS: Her cognition seemed normal (A 17-year-old, right-handed female patient). However, in spite of a normal visual field, her perception was missing on the left side, and she had no awareness of her deficit. She was unable to perceive the left side in each of 2 objects, regardless of position of the 2 objects, and failed at detail exploration of the left side of 1 object...
January 2018: Medicine (Baltimore)
Jesse Gomez, Vaidehi Natu, Brianna Jeska, Michael Barnett, Kalanit Grill-Spector
Receptive fields (RFs) processing information in restricted parts of the visual field are a key property of visual system neurons. However, how RFs develop in humans is unknown. Using fMRI and population receptive field (pRF) modeling in children and adults, we determine where and how pRFs develop across the ventral visual stream. Here we report that pRF properties in visual field maps, from the first visual area, V1, through the first ventro-occipital area, VO1, are adult-like by age 5. However, pRF properties in face-selective and character-selective regions develop into adulthood, increasing the foveal coverage bias for faces in the right hemisphere and words in the left hemisphere...
February 23, 2018: Nature Communications
Brittany M Jeye, Sean P MacEvoy, Jessica M Karanian, Scott D Slotnick
In the present functional magnetic resonance imaging (fMRI) study, we aimed to evaluate whether distinct regions of the hippocampus were associated with spatial memory for items presented in different locations of the visual field. In Experiment 1, during the study phase, participants viewed abstract shapes in the left or right visual field while maintaining central fixation. At test, old shapes were presented at fixation and participants classified each shape as previously in the "left" or "right" visual field followed by an "unsure"-"sure"-"very sure" confidence rating...
February 20, 2018: Brain Research
Constantin Tuleasca, Elena Najdenovska, Jean Régis, Tatiana Witjas, Nadine Girard, Jérôme Champoudry, Mohamed Faouzi, Jean-Philippe Thiran, Meritxell Bach Cuadra, Marc Levivier, Dimitri Van De Ville
OBJECTIVE: To evaluate functional connectivity (FC) of the ventro-lateral thalamus, a common target for drug-resistant essential tremor (ET), resting-state data were analyzed before and 1 year after stereotactic radiosurgical thalamotomy (SRS-T), and compared against healthy controls (HC). METHODS: 17 consecutive patients and 10 HC were enrolled. Tremor network was investigated using ventro-lateral ventral (VLV) nucleus as region-of-interest (ROI), extracted using automated segmentation from pretherapeutic diffusion MRI...
February 20, 2018: World Neurosurgery
Anita D'Anselmo, Felice Giuliani, Federica Campopiano, Emanuele Carta, Alfredo Brancucci
Musical setticlavio (literally, seven clefs) reading refers to the ability to read (i.e., to say aloud, without to sing) the musical note labels in the 7 musical clefs. The present research report aims to investigate hemispheric asymmetries in such a basic musical ability, very poorly investigated in the domain of cognitive neurosciences. Sixty-three musicians underwent lateralized tachistoscopic presentation of musical notes on staves, 50% in the left and 50% in the right visual field, associated with each of the 7 musical clefs...
February 22, 2018: Neuropsychology
Giulia Prete, Paolo Capotosto, Filippo Zappasodi, Luca Tommasi
OBJECTIVE: Four main theories concerning hemispheric asymmetries for emotional processing have been proposed: the right hemisphere hypothesis (RHH; the right hemisphere is specialized in processing all emotions), the valence hypothesis (VH; the left and the right hemispheres are superior in positive and negative emotion processing, respectively), the modified VH (the right-hemispheric superiority at posterior sites is followed by a valence-specific activity at frontal sites), and the motivational model (the left and the right hemispheres are superior in approaching-related and avoidance-related emotions, respectively)...
February 22, 2018: Neuropsychology
Fabienne Chetail, Mariagrazia Ranzini, Xavier De Tiège, Vincent Wens, Alain Content
Recent findings demonstrated readers' sensitivity to the distinction between consonant and vowel letters. Especially, the way consonants and vowels are organised within written words determines their perceptual structure. The present work attempted to overcome two limitations of previous studies by examining the neurophysiological correlates of this perceptual structure through magnetoencephalography (MEG). One aim was to establish that the extraction of vowel-centred units takes place during early stages of processing...
February 2, 2018: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Vanessa Andrada Păun, Zamfir-Radu Ionescu, Liliana Voinea, Monica Cîrstoiu, Alexandru Baroș, Ștefan Pricopie, Radu Ciuluvică
Ocular posterior pole modification are a pathological manifestation in complicated pregnancies, especially when pregnancy induced hypertension is present (PIH), as well as in preeclampsia (PE) or eclampsia. Nonetheless, as the pregnancy evolves, the possibility for an aggravated evolution with HELLP syndrome, disseminated intravascular coagulation, and idiopathic thrombocytopenic purpura may have an ocular manifestation that, mainly, implies a loss of visual field or acuity, that, left unattended, may constitute a permanent impairment...
April 2017: Romanian Journal of Ophthalmology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"