scholarly journals Altered Processing of Visual Stimuli in Vestibular Migraine Patients Between Attacks: A Combined VEP and sLORETA Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Jiahao Liu ◽  
Qi Zhang ◽  
Maojin Liang ◽  
Yajing Wang ◽  
Yuebo Chen ◽  
...  
Keyword(s):  
Visual Processing ◽  
Parietal Lobe ◽  
Visual Stimuli ◽  
Time Frame ◽  
Vestibular Migraine ◽  
Pathophysiological Mechanism ◽  
Low Level ◽  
Lower Amplitude ◽  
Healthy Control ◽  
Occipital Lobes

Objective: Vestibular migraine (VM) is one of the most common causes of recurrent vertigo, but the neural mechanisms that mediate such symptoms remain unknown. Since visual symptoms and photophobia are common clinical features of VM patients, we hypothesized that VM patients have abnormally sensitive low-level visual processing capabilities. This study aimed to investigate cortex abnormalities in VM patients using visual evoked potential (VEP) and standardized low-resolution brain electromagnetic tomography (sLORETA) analysis.Methods: We employed visual stimuli consisting of reversing displays of circular checkerboard patterns to examine “low-level” visual processes. Thirty-three females with VM and 20 healthy control (HC) females underwent VEP testing. VEP components and sLORETA were analyzed.Results: Patients with VM showed significantly lower amplitude and decreased latency of P1 activation compared with HC subjects. Further topographic mapping analysis revealed a group difference in the occipital area around P1 latency. sLORETA analysis was performed in the time frame of the P1 component and showed significantly less activity (deactivation) in VM patients in the frontal, parietal, temporal, limbic, and occipital lobes, as well as sub-lobar regions. The maximum current density difference was in the postcentral gyrus of the parietal lobe. P1 source density differences between HC subjects and VM patients overlapped with the vestibular cortical fields.Conclusion: The significantly abnormal response to visual stimuli indicates altered processing in VM patients. These findings suggest that abnormalities in vestibular cortical fields might be a pathophysiological mechanism of VM.

scholarly journals Exosomal MicroRNA Differential Expression in Plasma of Young Adults with Chronic Mild Traumatic Brain Injury and Healthy Control

Biomedicines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 36
Author(s):  
Rany Vorn ◽  
Maiko Suarez ◽  
Jacob C. White ◽  
Carina A. Martin ◽  
Hyung-Suk Kim ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Young Adults ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Pathophysiological Mechanism ◽  
Post Injury ◽  
Persistent Symptoms ◽  
Healthy Control ◽  
Underlying Mechanisms

Chronic mild traumatic brain injury (mTBI) has long-term consequences, such as neurological disability, but its pathophysiological mechanism is unknown. Exosomal microRNAs (exomiRNAs) may be important mediators of molecular and cellular changes involved in persistent symptoms after mTBI. We profiled exosomal microRNAs (exomiRNAs) in plasma from young adults with or without a chronic mTBI to decipher the underlying mechanisms of its long-lasting symptoms after mTBI. We identified 25 significantly dysregulated exomiRNAs in the chronic mTBI group (n = 29, with 4.48 mean years since the last injury) compared to controls (n = 11). These miRNAs are associated with pathways of neurological disease, organismal injury and abnormalities, and psychological disease. Dysregulation of these plasma exomiRNAs in chronic mTBI may indicate that neuronal inflammation can last long after the injury and result in enduring and persistent post-injury symptoms. These findings are useful for diagnosing and treating chronic mTBIs.

Visual Processing of Faces in Temporal Cortex: Physiological Evidence for a Modular Organization and Possible Anatomical Correlates

1991 ◽  
Vol 3 (1) ◽  
pp. 9-24 ◽  
Author(s):  
M. H. Harries ◽  
D. I. Perrett
Keyword(s):  
Parietal Cortex ◽  
Face Processing ◽  
Visual Processing ◽  
Fluorescent Dyes ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Superior Temporal Sulcus ◽  
Modular Organization ◽  
Spatial Awareness ◽  
Inferior Parietal Lobe

Physiological recordings along the length of the upper bank of the superior temporal sulcus (STS) revealed cells each of which was selectively responsive to a particular view of the head and body. Such cells were grouped in large patches 3-4 mm across. The patches were separated by regions of cortex containing cells responsive to other stimuli. The distribution of cells projecting from temporal cortex to the posterior regions of the inferior parietal lobe was studied with retrogradely transported fluorescent dyes. A strong temporoparietal projection was found originating from the upper bank of the STS. Cells projecting to the parietal cortex occurred in large patches or bands. The size and periodicity of modules defined through anatomical connections matched the functional subdivisions of the STS cortex involved in face processing evident in physiological recordings. It is speculated that the temporoparietal projections could provide a route through which temporal lobe analysis of facial signals about the direction of others' attention can be passed to parietal systems concerned with spatial awareness.

Motion-Induced Blindness

2017 ◽  
Author(s):  
Yoram Bonneh
Keyword(s):  
Visual Processing ◽  
Neural Correlates ◽  
Visual Signal ◽  
Low Level ◽  
Neural Correlates Of Consciousness ◽  
Visual Objects ◽  
Multistable Perception ◽  
Residual Processing ◽  
Potential Use ◽  
Moving Pattern

Motion-induced blindness (MIB) is a phenomenon characterized by “visual disappearance” in which relatively small but salient visual objects may disappear from one’s awareness intermittently for several seconds when embedded within a moving pattern. It is a compelling example of multistable perception in which physically invariant stimulation leads to fluctuations in perception. The interest in MIB stems from its potential use in studying visual processing outside the locus of awareness and the neural correlates of consciousness. Current studies of MIB provide evidence against low-level suppression of the visual signal and demonstrate residual processing of the invisible. This chapter explores these and related concepts.

scholarly journals Cognitive deficits and white matter abnormalities in never-treated first-episode schizophrenia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mi Yang ◽  
Shan Gao ◽  
Xiangyang Zhang
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
First Episode ◽  
Control Group ◽  
Pathophysiological Mechanism ◽  
Healthy Controls ◽  
Healthy Control ◽  
First Episode Schizophrenia

Abstract Cognitive impairment is viewed as a core symptom of schizophrenia (SCZ), but its pathophysiological mechanism remains unclear. White matter (WM) disruption is considered to be a central abnormality that may contribute to cognitive impairment in SCZ patients. However, few studies have addressed the association between cognition and WM integrity in never-treated first-episode (NTFE) patients with SCZ. In this study, we used the MATRICS Consensus Cognitive Battery (MCCB) to evaluate cognitive function in NTFE patients (n = 39) and healthy controls (n = 30), and associated it with whole-brain fractional anisotropy (FA) values obtained via voxel-based diffusion tensor imaging. We found that FA was lower in five brain areas of SCZ patients, including the cingulate gyrus, internal capsule, corpus callosum, cerebellum, and brainstem. Compared with the healthy control group, the MCCB’s total score and 8 out of 10 subscores were significantly lower in NTFE patients (all p < 0.001). Moreover, in patients but not healthy controls, the performance in the Trail Making Test was negatively correlated with the FA value in the left cingulate. Our findings provide evidence that WM disconnection is involved in some cognitive impairment in the early course of SCZ.

scholarly journals Functional divisions for visual processing in the central brain of flying Drosophila

2015 ◽  
Vol 112 (40) ◽  
pp. E5523-E5532 ◽  
Author(s):  
Peter T. Weir ◽  
Michael H. Dickinson
Keyword(s):  
Visual Processing ◽  
Visual Stimuli ◽  
Automated Analysis ◽  
Fruit Fly ◽  
Cell Types ◽  
Visual Responses ◽  
Behavioral Context ◽  
Central Brain ◽  
Brain Circuit ◽  
The Brain

Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit.

scholarly journals Neural Correlates of Motion-induced Blindness in the Human Brain

2010 ◽  
Vol 22 (6) ◽  
pp. 1235-1243 ◽  
Author(s):  
Marieke L. Schölvinck ◽  
Geraint Rees
Keyword(s):  
Visual Cortex ◽  
Visual Processing ◽  
Target Location ◽  
Visual Awareness ◽  
Neural Correlates ◽  
Low Level ◽  
Bistable Perception ◽  
Visual Phenomenon ◽  
High Level ◽  
Visual Cortical

Motion-induced blindness (MIB) is a visual phenomenon in which highly salient visual targets spontaneously disappear from visual awareness (and subsequently reappear) when superimposed on a moving background of distracters. Such fluctuations in awareness of the targets, although they remain physically present, provide an ideal paradigm to study the neural correlates of visual awareness. Existing behavioral data on MIB are consistent both with a role for structures early in visual processing and with involvement of high-level visual processes. To further investigate this issue, we used high field functional MRI to investigate signals in human low-level visual cortex and motion-sensitive area V5/MT while participants reported disappearance and reappearance of an MIB target. Surprisingly, perceptual invisibility of the target was coupled to an increase in activity in low-level visual cortex plus area V5/MT compared with when the target was visible. This increase was largest in retinotopic regions representing the target location. One possibility is that our findings result from an active process of completion of the field of distracters that acts locally in the visual cortex, coupled to a more global process that facilitates invisibility in general visual cortex. Our findings show that the earliest anatomical stages of human visual cortical processing are implicated in MIB, as with other forms of bistable perception.

scholarly journals Influence of visual stimuli on spatial navigation and memory of MCI, Alzheimer's disease patients and healthy control subjects

2017 ◽  
Vol 60 ◽  
pp. e88-e89
Author(s):  
Mélanie Cogné ◽  
Sophie Auriacombe ◽  
Louise Vasa ◽  
François Tison ◽  
Evelyne Klinger ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Spatial Navigation ◽  
Visual Stimuli ◽  
Control Subjects ◽  
Healthy Control

Prognostic value of mean platelet volume on tinnitus

2015 ◽  
Vol 130 (2) ◽  
pp. 162-165 ◽  
Author(s):  
O Kemal ◽  
T Müderris ◽  
F Başar ◽  
G Kutlar ◽  
F Gül
Keyword(s):  
Mean Platelet Volume ◽  
Healthy Subjects ◽  
Clinical Findings ◽  
University Hospital ◽  
Control Group ◽  
Study Group ◽  
Pathophysiological Mechanism ◽  
Platelet Volume ◽  
Significant Difference ◽  
Healthy Control

AbstractObjective:This study aimed to determine whether there was any relationship between tinnitus and mean platelet volume.Methods:This retrospective study was conducted between January 2013 and January 2014 in Ankara Atatürk Hospital and Ondokuz Mayıs University Hospital, Turkey, on a study group of 86 patients with tinnitus and a control group of 84 healthy subjects. Mean platelet volume was recorded and comparisons were made between the two groups.Results:Mean (± standard deviation) platelet volume was 7.67 ± 0.83 μm3 in the study group and 7.28 ± 0.56 μm3 in the control group. There was a statistically significant difference in mean platelet volume between the tinnitus patients and the healthy subjects (p < 0.05).Conclusion:The clinical findings indicated that tinnitus patients had a higher mean platelet volume than the healthy control subjects; however, the pathophysiological mechanism remains unclear.

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