scholarly journals LSD alters eyes-closed functional connectivity within the early visual cortex in a retinotopic fashion

2016 ◽  
Vol 37 (8) ◽  
pp. 3031-3040 ◽  
Author(s):  
Leor Roseman ◽  
Martin I. Sereno ◽  
Robert Leech ◽  
Mendel Kaelen ◽  
Csaba Orban ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Eyes Closed ◽  
Early Visual Cortex

scholarly journals LSD alters eyes-closed functional connectivity within the early visual cortex in a retinotopic fashion

2016 ◽  
Vol 16 (12) ◽  
pp. 133
Author(s):  
Leor Roseman ◽  
Martin Sereno ◽  
Robert Leech ◽  
Mendel Kaelen ◽  
Csaba Orban ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Eyes Closed ◽  
Early Visual Cortex

scholarly journals Dissociated mean and functional connectivity BOLD signals in visual cortex during eyes closed and fixation

2012 ◽  
Vol 108 (9) ◽  
pp. 2363-2372 ◽  
Author(s):  
Mark McAvoy ◽  
Linda Larson-Prior ◽  
Marek Ludwikow ◽  
Dongyang Zhang ◽  
Abraham Z. Snyder ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Primary Visual Cortex ◽  
Blood Oxygen Level Dependent ◽  
Extrastriate Cortex ◽  
Connected Components ◽  
Bold Signal ◽  
Thalamic Nuclei ◽  
Eyes Closed ◽  
Visual Areas

We investigated the effects of resting state type on blood oxygen level-dependent (BOLD) signal and functional connectivity in two paradigms: participants either alternated between fixation and eyes closed or maintained fixation or eyes closed throughout each scan. The BOLD signal and functional connectivity of lower and higher tiers of the visual cortical hierarchy were found to be differentially modulated during eyes closed versus fixation. Fixation was associated with greater mean BOLD signals in primary visual cortex and lower mean BOLD signals in extrastriate visual areas than periods of eyes closed. In addition, analysis of thalamocortical functional connectivity during scans in which participants maintained fixation showed synchronized BOLD fluctuations between those thalamic nuclei whose mean BOLD signal was systematically modulated during alternating epochs of eyes closed and fixation, primary visual cortex and the attention network, while during eyes closed negatively correlated fluctuations were seen between the same thalamic nuclei and extrastriate visual areas. Finally, in all visual areas the amplitude of spontaneous BOLD fluctuations was greater during eyes closed than during fixation. The dissociation between early and late tiers of visual cortex, which characterizes both mean and functionally connected components of the BOLD signal, may depend on the reorganization of thalamocortical networks. Since dissociated changes in local blood flow also characterize transitions between different stages of sleep and wakefulness (Braun AR, Balkin TJ, Wesenten NJ, Gwadry F, Carson RE, Varga M, Baldwin P, Belenky G, Herscovitch P. Science 279: 91–95, 1998), our results suggest that dissociated endogenous neural activity in primary and extrastriate cortex may represent a general aspect of brain function.

scholarly journals Action intention modulates the representation of object features in early visual cortex

2018 ◽  
Author(s):  
Jena Velji-Ibrahim ◽  
J. Douglas Crawford ◽  
Luigi Cattaneo ◽  
Simona Monaco
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Interaction Analysis ◽  
Action Planning ◽  
Hand Movements ◽  
Dominant Hand ◽  
Hand Orientation ◽  
Early Visual Cortex ◽  
Object Features ◽  
Decoding Accuracy

AbstractThe role of the early visual cortex (EVC) has been extensively studied for visual recognition but to a lesser degree to determine how action planning influences perceptual representations of objects. We used functional MRI and pattern classification methods to determine if during action planning, object features (orientation and location) could be decoded in an action-dependent way and if so, whether this was due to functional connectivity between visual and higher-level cortical areas. Sixteen participants used their right dominant hand to perform movements (Align or Open Hand) towards one of two oriented objects that were simultaneously presented and placed on either side of a fixation cross. While both movements required aiming toward target location, only Align movements required participants to precisely adjust hand orientation. Therefore, we hypothesized that if the representation of object features in the EVC is modulated by the upcoming action, we could use the pre-movement activity pattern to dissociate between object locations in both tasks, and orientations in the Align task only. We found above chance decoding accuracy between the two objects for both tasks in the calcarine sulcus corresponding to the peripheral location of the objects in the visual cortex, suggesting a task-independent (i.e. location) modulation. In contrast, we found significant decoding accuracy between the two objects for Align but not Open Hand movements in the occipital pole corresponding to central vision, and dorsal stream areas, suggesting a task-dependent (i.e. orientation) modulation. Psychophysiological interaction analysis indicated stronger functional connectivity during the planning phase of Align than Open Hand movements between EVC and sensory-motor areas in the dorsal and ventral visual stream, as well as areas that lie at the interface between the two streams. These results demonstrate that task-specific preparatory signals modulate activity not only in areas typically known to be involved in perception for action, but also in the EVC. Further, our findings suggest that object features that are relevant for successful action performance are represented in the part of the visual cortex that is best suited to process visual features in great details, such as the foveal cortex, even if the objects are viewed in the periphery.

scholarly journals Reduced Functional Connectivity in Children With Congenital Cataracts Using Resting-State Electroencephalography Measurement

2021 ◽  
Vol 15 ◽  
Author(s):  
Wan Chen ◽  
Liping Lan ◽  
Wei Xiao ◽  
Jiahong Li ◽  
Jiahao Liu ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
Functional Improvement ◽  
Control Group ◽  
Salience Network ◽  
Alpha Band ◽  
Congenital Cataracts ◽  
Eyes Closed ◽  
Parietal Cortices

ObjectivesNumerous task-based functional magnetic resonance imaging studies indicate the presence of compensatory functional improvement in patients with congenital cataracts. However, there is neuroimaging evidence that shows decreased sensory perception or cognition information processing related to visual dysfunction, which favors a general loss hypothesis. This study explored the functional connectivity between visual and other networks in children with congenital cataracts using resting state electroencephalography.MethodsTwenty-one children with congenital cataracts (age: 8.02 ± 2.03 years) and thirty-five sex- and age-matched normal sighted controls were enrolled to investigate functional connectivity between the visual cortex and the default mode network, the salience network, and the cerebellum network during resting state electroencephalography (eyes closed) recordings.ResultThe congenital cataract group was less active, than the control group, in the occipital, temporal, frontal and limbic lobes in the theta, alpha, beta1 and beta2 frequency bands. Additionally, there was reduced alpha-band connectivity between the visual and somatosensory cortices and between regions of the frontal and parietal cortices associated with cognitive and attentive control.ConclusionThe results indicate abnormalities in sensory, cognition, motion and execution functional connectivity across the developing brains of children with congenital cataracts when compared with normal controls. Reduced frontal alpha activity and alpha-band connectivity between the visual cortex and salience network might reflect attenuated inhibitory information flow, leading to higher attentional states, which could contribute to adaptation of environmental change in this group of patients.

scholarly journals Spontaneously emerging patterns in human visual cortex and their functional connectivity are linked to the patterns evoked by visual stimuli

2020 ◽  
Vol 124 (5) ◽  
pp. 1343-1363
Author(s):  
DoHyun Kim ◽  
Tomer Livne ◽  
Nicholas V. Metcalf ◽  
Maurizio Corbetta ◽  
Gordon L. Shulman
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Spontaneous Activity ◽  
Spatial Patterns ◽  
Brain Activity ◽  
Spontaneous Brain Activity ◽  
Emerging Patterns ◽  
Early Visual Cortex ◽  
Functional Explanations ◽  
High Level

Spontaneous brain activity was once thought to reflect only noise, but evidence of strong spatiotemporal regularities has motivated a search for functional explanations. Here we show that the spatial pattern of spontaneous activity in human high-level and early visual cortex is related to the spatial patterns evoked by stimuli. Moreover, these patterns partly govern spontaneous spatiotemporal interactions between regions, so-called functional connectivity. These results support the hypothesis that spontaneous activity serves a representational function.

scholarly journals Reorganization of early visual cortex functional connectivity following selective peripheral and central visual loss

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Norman Sabbah ◽  
Nicolae Sanda ◽  
Colas N. Authié ◽  
Saddek Mohand-Saïd ◽  
José-Alain Sahel ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Visual Loss ◽  
Early Visual Cortex

scholarly journals Affective learning enhances activity and functional connectivity in early visual cortex

2009 ◽  
Vol 47 (12) ◽  
pp. 2480-2487 ◽  
Author(s):  
Eswar Damaraju ◽  
Yang-Ming Huang ◽  
Lisa Feldman Barrett ◽  
Luiz Pessoa
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Affective Learning ◽  
Early Visual Cortex

Continuous theta burst transcranial magnetic stimulation reduces resting state connectivity between visual areas

2013 ◽  
Vol 110 (8) ◽  
pp. 1811-1821 ◽  
Author(s):  
Dobromir Rahnev ◽  
Peter Kok ◽  
Moniek Munneke ◽  
Linda Bahdo ◽  
Floris P. de Lange ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
Brain Activity ◽  
Brain Regions ◽  
Perceptual Task ◽  
Target Area ◽  
Resting State Functional Connectivity ◽  
Early Visual Cortex ◽  
Theta Burst

Continuous theta burst stimulation (cTBS) is a technique that allows for altering of brain activity. Research to date has focused on the effect of cTBS on the target area, but less is known about its effects on the resting state functional connectivity between different brain regions. We investigated this issue by applying cTBS to the occipital cortex and probing its influence in retinotopically defined regions in early visual cortex using functional MRI. We found that occipital cTBS reliably decreased the resting state functional connectivity (i.e., the correlation of spontaneous activity) between regions of the early visual cortex. In the context of a perceptual task, such an effect could mean that cTBS affects the strength of the perceptual signal, its variability, or both. We investigated this issue in a second experiment in which subjects performed a perceptual discrimination task and indicated their level of certainty on each trial. The results showed that occipital cTBS decreased both subjects' accuracy and confidence. Signal detection modeling suggested that these impairments resulted primarily from a decreased strength of the perceptual signal, with a nonsignificant trend of a decrease in signal variability. We discuss the implications of these experiments for understanding the mechanisms by which cTBS influences brain activity and perceptual processes.

scholarly journals Functional connectivity between the thalamus and visual cortex under eyes closed and eyes open conditions: A resting-state fMRI study

2009 ◽  
Vol 30 (9) ◽  
pp. 3066-3078 ◽  
Author(s):  
Qihong Zou ◽  
Xiangyu Long ◽  
Xinian Zuo ◽  
Chaogan Yan ◽  
Chaozhe Zhu ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Resting State ◽  
Resting State Fmri ◽  
Eyes Closed ◽  
Fmri Study ◽  
Eyes Open
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