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Frontal Eye Field

Richard Bido-Medina, Jonathan Wirsich, Minelly Rodríguez, Jairo Oviedo, Isidro Miches, Pamela Bido, Luis Tusen, Peter Stoeter, Sepideh Sadaghiani
Objective: To determine the impact of Zika virus (ZIKV) infection on brain structure and functional organization of severely affected adult patients with neurological complications that extend beyond Guillain-Barré Syndrome (GBS)-like manifestations and include symptoms of the central nervous system (CNS). Methods: In this first case-control neuroimaging study, we obtained structural and functional magnetic resonance images in nine rare adult patients in the subacute phase, and healthy age- and sex-matched controls...
June 2018: Annals of Clinical and Translational Neurology
Tobias Otto, Fred R H Zijlstra, Rainer Goebel
Investing mental effort is costly, and the investment has to be matched by a reward to make a person engage in task performance. However, the neural structures underlying the continued management of mental effort are not known. Previous work has identified left-lateralized structures, most prominently the left anterior Insular Cortex (aIC) as regions implied in post-hoc evaluation and also anticipation of mental effort investment. We present a study aimed at identifying neural structures that are sensitive to changes in both task load and fatigue-induced state load...
2018: PloS One
Ernesto Durán, Carlos N Oyanedel, Niels Niethard, Marion Inostroza, Jan Born
Mammalian sleep comprises the stages of slow-wave sleep (SWS) and rapid eye movement (REM) sleep. Additionally, a transition state is often discriminated which in rodents is termed intermediate stage (IS). Although these sleep stages are thought of as unitary phenomena affecting the whole brain in a congruent fashion, recent findings have suggested that sleep stages can also appear locally restricted to specific networks and regions. Here, we compared in rats sleep stages and their transitions between neocortex and hippocampus...
June 1, 2018: Sleep
Monika Wojtczak-Kwaśniewska, Anna Przekoracka-Krawczyk, Rob H J Van der Lubbe
Source analyses on event related potentials (ERPs) derived from the electroencephalogram (EEG) were performed to examine the respective roles of cortical areas preceding exogenously triggered saccades, combined convergences, and combined divergences. All eye movements were triggered by the offset of a central fixation light emitting diode (LED) and the onset of a lateral LED at various depths in an otherwise fully darkened room. Our analyses revealed that three source pairs, two located in the frontal lobe-the frontal eye fields (FEF) and an anterior frontal area-, and one located within the occipital cortex, can account for 99...
2018: PloS One
Takashi Ogawa, Yuji Ueno, Hikaru Kamo, Nobukazu Miyamoto, Kazuo Yamashiro, Ryota Tanaka, Yasushi Shimo, Nobutaka Hattori
Conjugate eye deviation (CED) is defined as a sustained shift in horizontal gaze toward 1 side, together with gaze failure to the other side, caused by lesions in the brainstem, basal ganglia, or cortical frontal eye fields. To date, very few reports have described CED in patients with medullary infarction. A 76-year-old woman presented with sudden onset of vertigo and right hemiparesis, accompanied by CED to the right with gaze palsy to the left. Her brain magnetic resonance imaging showed left upper medial medullary infarction involving the left nucleus prepositus hypoglossi (NPH) and adjacent to the left inferior olivary nucleus (ION)...
May 31, 2018: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
Kyle M Gilbert, David J Schaeffer, Peter Zeman, Jörn Diedrichsen, Stefan Everling, Julio C Martinez-Trujillo, J Andrew Pruszynski, Ravi S Menon
The close homology of monkeys and humans has increased the prevalence of non-human-primate models in functional MRI studies of brain connectivity. To improve upon the attainable resolution in functional MRI studies, a commensurate increase in the sensitivity of the radiofrequency receiver coil is required to avoid a reduction in the statistical power of the analysis. Most receive coils are comprised of multiple loops distributed equidistantly over a surface to produce spatially independent sensitivity profiles...
May 28, 2018: NeuroImage
Mário Pincelli Netto, Pedro Vanalle Ferrari, Bruno Torres Herrerias, Flávio Eduardo Hirai, Carolina Pelegrini Barbosa Gracitelli
Differentiating glaucomatous from nonglaucomatous optic disc cupping remains challenging. We present a case of a 48-year-old woman with an internal carotid aneurysm of approximately 3.5 mm × 6.5 mm that mimicked normal-tension glaucoma. The patient had a 2-year history of low vision acuity in her left eye and frontal oppressive headache. Owing to the carotid aneurysm, she developed an asymmetric vertical cup-to-disc ratio above 0.2, and marked inferotemporal neuronal rim loss and pallor of the residual rim were noted in the left disc...
April 2018: Arquivos Brasileiros de Oftalmologia
Suryadeep Dash, Tyler R Peel, Stephen G Lomber, Brian D Corneil
A neural correlate for saccadic reaction times (SRTs) in the gap saccade task is the level of low-frequency activity in the intermediate layers of the superior colliculus (iSC) just before visual target onset: greater levels of such preparatory iSC low-frequency activity precede shorter SRTs. The frontal eye fields (FEFs) are one likely source of iSC preparatory activity, since FEF preparatory activity is also inversely related to SRT. To better understand the FEF's role in saccade preparation, and the way in which such preparation relates to SRT, in two male rhesus monkeys, we compared iSC preparatory activity across unilateral reversible cryogenic inactivation of the FEF...
March 2018: ENeuro
Daisuke Sudo, Youichi Doutake, Hidenori Yokota, Eiju Watanabe
Stuttering occurs in approximately 5% of all children and 1% of adults. One type, neurogenic stuttering, is usually attributable to strokes or other structural damages to the brain areas that are responsible for language fluency. Here, we present the first case of neurogenic stuttering caused by a brain abscess. The patient was a 60-year-old man admitted for a seizure and administered an anticonvulsant, after which he began stuttering. MRI revealed a brain abscess in the left frontal lobe that extended to the dorsolateral prefrontal cortex (BA (Brodmann's area) 9 and 46), frontal eye field (BA 8) and premotor cortex and supplementary motor area (BA 6)...
May 12, 2018: BMJ Case Reports
Katerina Lukasova, Mariana P Nucci, Raymundo Machado de Azevedo Neto, Gilson Vieira, João R Sato, Edson Amaro
Saccades were assessed in 21 adults (age 24 years, SD = 4) and 15 children (age 11 years, SD = 1), using combined functional magnetic resonance imaging (fMRI) and eye-tracking. Subjects visually tracked a point on a horizontal line in four conditions: time and position predictable task (PRED), position predictable (pPRED), time predictable (tPRED) and visually guided saccades (SAC). Both groups in the PRED but not in pPRED, tPRED and SAC produced predictive saccades with latency below 80 ms. In task versus group comparisons, children's showed less efficient learning compared to adults for predictive saccades (adults = 48%, children = 34%, p = 0...
2018: PloS One
Thomas R Reppert, Mathieu Servant, Richard P Heitz, Jeffrey D Schall
Balancing the speed-accuracy tradeoff (SAT) is necessary for successful behavior. Using a visual search task with interleaved cues emphasizing speed or accuracy, we recently reported diverse contributions of frontal eye field (FEF) neurons instantiating salience evidence and response preparation. Here we report replication of visual search SAT performance in two macaque monkeys, new information about variation of saccade dynamics with SAT, extension of the neurophysiological investigation to describe processes in the superior colliculus, and description of the origin of search errors in this task...
April 18, 2018: Journal of Neurophysiology
Christopher K Hauser, Dantong Zhu, Terrence R Stanford, Emilio Salinas
In studies of voluntary movement, a most elemental quantity is the reaction time (RT) between the onset of a visual stimulus and a saccade toward it. However, this RT demonstrates extremely high variability which, in spite of extensive research, remains unexplained. It is well established that, when a visual target appears, oculomotor activity gradually builds up until a critical level is reached, at which point a saccade is triggered. Here, based on computational work and single-neuron recordings from monkey frontal eye field (FEF), we show that this rise-to-threshold process starts from a dynamic initial state that already contains other incipient, internally driven motor plans, which compete with the target-driven activity to varying degrees...
April 13, 2018: ELife
Aaron Kucyi, Jessica Schrouff, Stephan Bickel, Brett L Foster, James M Shine, Josef Parvizi
Evidence for intrinsic functional connectivity (FC) within the human brain is largely from neuroimaging studies of hemodynamic activity. Data are lacking from anatomically precise electrophysiological recordings in the most widely studied nodes of human brain networks. Here we used a combination of fMRI and electrocorticography (ECoG) in five human neurosurgical patients with electrodes in the canonical "default" (medial prefrontal and posteromedial cortex), "dorsal attention" (frontal eye fields and superior parietal lobule), and "frontoparietal control" (inferior parietal lobule and dorsolateral prefrontal cortex) networks...
April 25, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Dimitris A Pinotsis, Timothy J Buschman, Earl K Miller
There is a severe limitation in the number of items that can be held in working memory. However, the neurophysiological limits remain unknown. We asked whether the capacity limit might be explained by differences in neuronal coupling. We developed a theoretical model based on Predictive Coding and used it to analyze Cross Spectral Density data from the prefrontal cortex (PFC), frontal eye fields (FEF), and lateral intraparietal area (LIP). Monkeys performed a change detection task. The number of objects that had to be remembered (memory load) was varied (1-3 objects in the same visual hemifield)...
March 28, 2018: Cerebral Cortex
Sevdalina Kandilarova, Drozdstoy Stoyanov, Stefan Kostianev, Karsten Specht
Depression has been associated with changes in both functional and effective connectivity of large scale brain networks, including the default mode network, executive network, and salience network. However, studies of effective connectivity by means of spectral dynamic causal modeling (spDCM) are still rare and the interaction between the different resting state networks has not been investigated in detail. Thus, we aimed at exploring differences in effective connectivity among eight right hemisphere brain areas-anterior insula, inferior frontal gyrus, middle frontal gyrus (MFG), frontal eye field, anterior cingulate cortex, superior parietal lobe, amygdala, and hippocampus, between a group of healthy controls ( N  = 20) and medicated depressed patients ( N  = 20)...
2018: Frontiers in Psychiatry
Lisa A Jacobson, Deana Crocetti, Benjamin Dirlikov, Keith Slifer, Martha Bridge Denckla, Stewart H Mostofsky, E Mark Mahone
OBJECTIVES: Attention-deficit/hyperactivity disorder (ADHD) is a common neurological disorder with symptom onset early in childhood. Growing evidence suggests anomalous brain development across multiple brain regions is evident in school-aged children; however, few studies have examined whether such differences are notable in the preschool years when symptom onset typically occurs. METHODS: High resolution anatomical (MPRAGE) images and cognitive and behavioral measures were analyzed in a total of 90 medication-naïve preschoolers, ages 4-5 years (52 with ADHD, 38 controls; 64...
March 26, 2018: Journal of the International Neuropsychological Society: JINS
Francesco Pellegrini, Andrew G Lee, Cristina Cercato
A 49-year-old previously healthy woman presented with acute painless visual loss in the right eye, a right relative afferent pupillary defect, and a normal fundus examination. She was diagnosed with retrobulbar "optic neuritis" and given a course of intravenous steroids. Despite treatment, however, she continued to lose vision and serial visual field testing confirmed a junctional scotoma in the fellow eye. Cranial magnetic resonance imaging (MRI) showed a mass at the junction between the right optic nerve and the anterior aspect of the chiasm and a right frontal lesion that proved to be multicentric glioblastoma multiforme...
April 2018: Neuro-ophthalmology
Eleftherios Neromyliotis, Adonis K Moschovakis
We studied the phasic saccade related discharges of single neurons (S neurons) of the premotor cortex of female rhesus monkeys, mostly in the caudal bank of the arcuate sulcus. As described in previous work from our laboratory (Neromyliotis and Moschovakis, 2017b), some of these cells emitted phasic discharges for coordinated movements of the eyes and hand as well as for movements of either effector executed in isolation (motor equivalence -Meq). Other cells (S), did not emit phasic discharges for hand movements unaccompanied by saccades...
March 14, 2018: Journal of Neurophysiology
Carl Arndt, Mathieu Costantini, Christophe Chiquet, Mickael Afriat, Sylvie Berthemy, Vivien Vasseur, Alain Ducasse, Martine Mauget-Faÿsse
PURPOSE: Pericentral visual field changes and disruption of the ellipsoid layer on spectral domain optical coherence tomography (SD-OCT) are the main features of antimalarial retinal toxicity. C-Scan OCT or "en face" enables a topographic frontal view of the changes observed within the different retinal layers in particular the ellipsoid layer. The aim of this prospective study was to compare multifocal ERG (mfERG) responses with the results of C-Scan OCT ("en face" OCT) in patients with abnormal visual field and to analyze relationships between the structural and functional abnormalities...
April 2018: Documenta Ophthalmologica. Advances in Ophthalmology
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
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