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Frontal Eye Field

Annie L Shelton, Kim Cornish, Meaghan Clough, Sanuji Gajamange, Scott Kolbe, Joanne Fielding
Executive dysfunction has been demonstrated among premutation (PM) carriers (55-199 CGG repeats) of the Fragile X mental retardation 1 (FMR1) gene. Further, alterations to neural activation patterns have been reported during memory and comparison based functional magnetic resonance imaging (fMRI) tasks in these carriers. For the first time, the relationships between fMRI neural activation during an interleaved ocular motor prosaccade/antisaccade paradigm, and concurrent task performance (saccade measures of latency, accuracy and error rate) in PM females were examined...
October 14, 2016: Human Brain Mapping
Yukihisa Suzuki, Motohiro Kiyosawa, Kiichi Ishiwata, Keiichi Oda, Kenji Ishii
Bell's phenomenon is a physiological phenomenon wherein the eye ball involuntarily rolls upward during eyelid closing. Although this phenomenon occurs in healthy individuals, the neural mechanism related to Bell's phenomenon has not yet been identified. We aimed to investigate the brain regions relevant to Bell's phenomenon and volitional eye movement using [(15)O] H2O and positron emission tomography (PET). We measured regional cerebral blood flow (rCBF) in 8 normal subjects under 3 conditions: at rest with eyes closed, during opening and closing of the eyelids in response to sound stimuli (lid opening/closing), and during vertical movement of the eyes with lids closed in response to sound stimuli (volitional eye movement)...
2016: Tohoku Journal of Experimental Medicine
Shao-Min Hung, Dan Milea, Annadata Venkata Rukmini, Raymond P Najjar, Joo Huang Tan, Françoise Viénot, Marie Dubail, Sharon Lee Choon Tow, Tin Aung, Joshua J Gooley, Po-Jang Hsieh
Photic stimulation of rods, cones and intrinsically photosensitive melanopsin-containing retinal ganglion cells (ipRGCs) mediates non-visual light responses, including entrainment of circadian rhythms and pupillary light reflex. Unlike visual responses to photic stimulation, the cerebral correlates of non-visual light responses in humans remains elusive. In this study, we used functional magnetic resonance imaging (fMRI) in 14 healthy young participants, to localize cerebral regions which are differentially activated by metameric light that gave rise to different levels of melanopic excitation...
September 26, 2016: NeuroImage
Rebecca Marie Krock, Tirin Moore
Primate vision is continuously disrupted by saccadic eye movements, and yet this disruption goes unperceived. One mechanism thought to reduce perception of this self-generated movement is saccadic suppression, a global loss of visual sensitivity just before, during, and after saccadic eye movements. The frontal eye field (FEF) is a candidate source of neural correlates of saccadic suppression previously observed in visual cortex because it contributes to the generation of visually guided saccades and modulates visual cortical responses...
September 28, 2016: Journal of Neurophysiology
Mo Chen, Bing Li, Jing Guang, Linyu Wei, Si Wu, Yu Liu, Mingsha Zhang
Although the cerebral cortex is thought to be composed of functionally distinct areas, the actual parcellation of area and assignment of function are still highly controversial. An example is the much-studied lateral intraparietal cortex (LIP). Despite the general agreement that LIP plays an important role in visual-oculomotor transformation, it remains unclear whether the area is primary sensory- or motor-related (the attention-intention debate). Although LIP has been considered as a functionally unitary area, its dorsal (LIPd) and ventral (LIPv) parts differ in local morphology and long-distance connectivity...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Kai Nitschke, Lena Köstering, Lisa Finkel, Cornelius Weiller, Christoph P Kaller
The ability to mentally design and evaluate series of future actions has often been studied in terms of planning abilities, commonly using well-structured laboratory tasks like the Tower of London (ToL). Despite a wealth of studies, findings on the specific localization of planning processes within prefrontal cortex (PFC) and on the hemispheric lateralization are equivocal. Here, we address this issue by integrating evidence from two different sources of data: First, we provide a systematic overview of the existing lesion data on planning in the ToL (10 studies, 211 patients) which does not indicate any evidence for a general lateralization of planning processes in (pre)frontal cortex...
September 15, 2016: Human Brain Mapping
Greg L West, Sarah Lippé
Chronological age is related positively to a participant's ability to inhibit distracting information. Inhibition can be measured using the trajectory deviation of a saccade. Saccadic curvature away from distracting visual information is controlled through top-down inhibition mediated by the frontal eye fields. In the present study, we aimed to further test the saccadic trajectory deviation paradigm's sensitivity to the development of frontal inhibitory procuresses by comparing its measure of saccadic inhibition with that of a widely used paradigm, namely, the antisaccade task...
November 9, 2016: Neuroreport
Luca Cocchi, Martin V Sale, Leonardo L Gollo, Peter T Bell, Vinh T Nguyen, Andrew Zalesky, Michael Breakspear, Jason B Mattingley
Within the primate visual system, areas at lower levels of the cortical hierarchy process basic visual features, whereas those at higher levels, such as the frontal eye fields (FEF), are thought to modulate sensory processes via feedback connections. Despite these functional exchanges during perception, there is little shared activity between early and late visual regions at rest. How interactions emerge between regions encompassing distinct levels of the visual hierarchy remains unknown. Here we combined neuroimaging, non-invasive cortical stimulation and computational modelling to characterize changes in functional interactions across widespread neural networks before and after local inhibition of primary visual cortex or FEF...
2016: ELife
Ana B Chica, Dimitri J Bayle, Fabiano Botta, Paolo Bartolomeo, Pedro M Paz-Alonso
Only a small fraction of all the information reaching our senses can be the object of conscious report or voluntary action. Although some models propose that different attentional states (top-down amplification and vigilance) are necessary for conscious perception, few studies have explored how the brain activations associated with different attentional systems (such as top-down orienting and phasic alerting) lead to conscious perception of subsequent visual stimulation. The aim of the present study was to investigate the neural mechanisms associated with endogenous spatial attention and phasic alertness, and their interaction with the conscious perception of near-threshold stimuli...
2016: Scientific Reports
Devon A Greer, Kathryn Bonnen, Alexander C Huk, Lawrence K Cormack
Some animals with lateral eyes (such as bees) control their navigation through the 3D world using velocity differences between the two eyes. Other animals with frontal eyes (such as primates, including humans) can perceive 3D motion based on the different velocities that a moving object projects upon the two retinae. Although one type of 3D motion perception involves a comparison between velocities from vastly different (monocular) portions of the visual field, and the other involves a comparison within overlapping (binocular) portions of the visual field, both compare velocities across the two eyes...
August 1, 2016: Journal of Vision
Christiane S Rohr, Sarah A Vinette, Kari A L Parsons, Ivy Y K Cho, Dennis Dimond, Alina Benischek, Catherine Lebel, Deborah Dewey, Signe Bray
Early childhood is a period of profound neural development and remodeling during which attention skills undergo rapid maturation. Attention networks have been extensively studied in the adult brain, yet relatively little is known about changes in early childhood, and their relation to cognitive development. We investigated the association between age and functional connectivity (FC) within the dorsal attention network (DAN) and the association between FC and attention skills in early childhood. Functional magnetic resonance imaging data was collected during passive viewing in 44 typically developing female children between 4 and 7 years whose sustained, selective, and executive attention skills were assessed...
August 13, 2016: Cerebral Cortex
Masahiro Hata, Toshihisa Tanaka, Hiroaki Kazui, Ryouhei Ishii, Leonides Canuet, Roberto D Pascual-Marqui, Yasunori Aoki, Shunichiro Ikeda, Shunsuke Sato, Yukiko Suzuki, Hideki Kanemoto, Kenji Yoshiyama, Masao Iwase
Recently, cerebrospinal fluid (CSF) biomarkers related to Alzheimer's disease (AD) have garnered a lot of clinical attention. To explore neurophysiological traits of AD and parameters for its clinical diagnosis, we examined the association between CSF biomarkers and electroencephalography (EEG) parameters in 14 probable AD patients. Using exact low-resolution electromagnetic tomography (eLORETA), artifact-free 40-sesond EEG data were estimated with current source density (CSD) and lagged phase synchronization (LPS) as the EEG parameters...
August 11, 2016: Clinical EEG and Neuroscience: Official Journal of the EEG and Clinical Neuroscience Society (ENCS)
Tyler R Peel, Ziad M Hafed, Suryadeep Dash, Stephen G Lomber, Brian D Corneil
Microsaccades aid vision by helping to strategically sample visual scenes. Despite the importance of these small eye movements, no cortical area has ever been implicated in their generation. Here, we used unilateral and bilateral reversible inactivation of the frontal eye fields (FEF) to identify a cortical drive for microsaccades. Unexpectedly, FEF inactivation altered microsaccade metrics and kinematics. Such inactivation also impaired microsaccade deployment following peripheral cue onset, regardless of cue side or inactivation configuration...
August 2016: PLoS Biology
Edward F Ester, David W Sutterer, John T Serences, Edward Awh
UNLABELLED: Control over visual selection has long been framed in terms of a dichotomy between "source" and "site," where top-down feedback signals originating in frontoparietal cortical areas modulate or bias sensory processing in posterior visual areas. This distinction is motivated in part by observations that frontoparietal cortical areas encode task-level variables (e.g., what stimulus is currently relevant or what motor outputs are appropriate), while posterior sensory areas encode continuous or analog feature representations...
August 3, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Inês R Violante, Miguel Patricio, Inês Bernardino, José Rebola, Antero J Abrunhosa, Nuno Ferreira, Miguel Castelo-Branco
OBJECTIVE: To provide a comprehensive investigation of the γ-aminobutyric acid (GABA) system in patients with neurofibromatosis type 1 (NF1) that allows understanding the nature of the GABA imbalance in humans at pre- and postsynaptic levels. METHODS: In this cross-sectional study, we employed multimodal imaging and spectroscopy measures to investigate GABA type A (GABAA) receptor binding, using [(11)C]-flumazenil PET, and GABA concentration, using magnetic resonance spectroscopy (MRS)...
August 30, 2016: Neurology
Svenja Gremmler, Markus Lappe
Saccadic adaptation is the motor learning process that keeps saccade amplitudes on target. This process is eye position specific: amplitude adaptation that is induced for a saccade at one particular location in the visual field transfers incompletely to saccades at other locations. In our current study, we investigated wether this eye position signal corresponds to the initial or to the final eye position of the saccade. Each case would have different implications on the mechanisms of adaptation. The initial eye position is not directly available, when the adaptation driving post saccadic error signal is received...
2016: Frontiers in Human Neuroscience
Alexander Thiele, Christian Brandt, Miguel Dasilva, Sascha Gotthardt, Daniel Chicharro, Stefano Panzeri, Claudia Distler
UNLABELLED: Top-down attention increases coding abilities by altering firing rates and rate variability. In the frontal eye field (FEF), a key area enabling top-down attention, attention induced firing rate changes are profound, but its effect on different cell types is unknown. Moreover, FEF is the only cortical area investigated in which attention does not affect rate variability, as assessed by the Fano factor, suggesting that task engagement affects cortical state nonuniformly. We show that putative interneurons in FEF of Macaca mulatta show stronger attentional rate modulation than putative pyramidal cells...
July 20, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
K Sathian
Haptic sensing of objects acquires information about a number of properties. This review summarizes current understanding about how these properties are processed in the cerebral cortex of macaques and humans. Nonnoxious somatosensory inputs, after initial processing in primary somatosensory cortex, are partially segregated into different pathways. A ventrally directed pathway carries information about surface texture into parietal opercular cortex and thence to medial occipital cortex. A dorsally directed pathway transmits information regarding the location of features on objects to the intraparietal sulcus and frontal eye fields...
October 1, 2016: Journal of Neurophysiology
Alexandra Battaglia-Mayer, Lucy Babicola, Eleonora Satta
In monkeys, motor intention in its different forms emerges from a parietal-frontal gradient of visual, eye and hand signals, containing discrete dominant domains. These are formed by areas sharing cortical connections and functional properties. Within this gradient, the combination of different inputs determines the tuning properties of neurons, while local and long cortico-cortical connections shape the structure and temporal delays of the network. The pathways linking similar functional domains in parietal and frontal cortex sculpt information processing systems related to different functions, all requiring eye-hand coordination...
July 12, 2016: Neuroscience
Maryam Ghahremani, R Matthew Hutchison, Ravi S Menon, Stefan Everling
In contrast to the well established macaque monkey, little is known about functional connectivity patterns of common marmoset monkey (Callithrix jacchus) that is poised to become the leading transgenic primate model. Here, we used resting-state ultra-high-field fMRI data collected from anesthetized marmosets and macaques along with awake human subjects, to examine and compare the brain's functional organization, with emphasis on the saccade system. Exploratory independent component analysis revealed eight resting-state networks in marmosets that greatly overlapped with corresponding macaque and human networks including a distributed frontoparietal network...
July 11, 2016: Cerebral Cortex
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