keyword
MENU ▼
Read by QxMD icon Read
search

Primary visual cortex

keyword
https://www.readbyqxmd.com/read/28433446/functional-magnetic-resonance-imaging-to-assess-the-neurobehavioral-impact-of-dysphotopsia-with-multifocal-intraocular-lenses
#1
Andreia M Rosa, Ângela C Miranda, Miguel Patrício, Colm McAlinden, Fátima L Silva, Joaquim N Murta, Miguel Castelo-Branco
PURPOSE: To investigate the association between dysphotopsia and neural responses in visual and higher-level cortical regions in patients who recently received multifocal intraocular lens (IOL) implants. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty patients 3 to 4 weeks after bilateral cataract surgery with diffractive IOL implantation and 15 age- and gender-matched control subjects. METHODS: Functional magnetic resonance imaging (fMRI) was performed when participants viewed low-contrast grating stimuli...
April 19, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28432140/visually-evoked-3-5-hz-membrane-potential-oscillations-reduce-the-responsiveness-of-visual-cortex-neurons-in-awake-behaving-mice
#2
Michael C Einstein, Pierre-Olivier Polack, Duy T Tran, Peyman Golshani
Low frequency membrane potential (Vm) oscillations were once thought to only occur in sleeping and anesthetized states. Recently, low frequency Vm oscillations have been described in inactive awake animals, but it is unclear if they shape sensory processing in neurons and whether they occur during active awake behavioral states. To answer these questions, we performed two-photon guided whole-cell Vm recordings from primary visual cortex layer 2/3 excitatory and inhibitory neurons in awake mice during passive visual stimulation and performance of visual and auditory discrimination tasks...
April 21, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28424611/modafinil-induced-changes-in-functional-connectivity-in-the-cortex-and-cerebellum-of-healthy-elderly-subjects
#3
Miriam Punzi, Tommaso Gili, Laura Petrosini, Carlo Caltagirone, Gianfranco Spalletta, Stefano L Sensi
In the past few years, cognitive enhancing drugs (CEDs) have gained growing interest and the focus of investigations aimed at exploring their use to potentiate the cognitive performances of healthy individuals. Most of this exploratory CED-related research has been performed on young adults. However, CEDs may also help to maintain optimal brain functioning or compensate for subtle and or subclinical deficits associated with brain aging or early-stage dementia. In this study, we assessed effects on resting state brain activity in a group of healthy elderly subjects undergoing acute administration of modafinil, a wakefulness-promoting agent...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28424573/global-sensory-qualities-and-aesthetic-experience-in-music
#4
Pauli Brattico, Elvira Brattico, Peter Vuust
A well-known tradition in the study of visual aesthetics holds that the experience of visual beauty is grounded in global computational or statistical properties of the stimulus, for example, scale-invariant Fourier spectrum or self-similarity. Some approaches rely on neural mechanisms, such as efficient computation, processing fluency, or the responsiveness of the cells in the primary visual cortex. These proposals are united by the fact that the contributing factors are hypothesized to be global (i.e., they concern the percept as a whole), formal or non-conceptual (i...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28420970/single-session-anodal-tdcs-with-small-size-stimulating-electrodes-over-frontoparietal-superficial-sites-does-not-affect-motor-sequence-learning
#5
Fahimeh Hashemirad, Paul B Fitzgerald, Maryam Zoghi, Shapour Jaberzadeh
Due to the potential of anodal transcranial direct current stimulation (a-tDCS) for enhancement of fine sequenced movements and increasing interest in achieving high level of fine movements in the trained and untrained hands especially at initial stage of learning, we designed this study to investigate whether the application of single-session a-tDCS with small-size stimulating electrodes over FPN sites, such as dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1) or posterior parietal cortex (PPC) could enhance sequence learning with the trained hand and these effects are transferred into the untrained hand or not...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28420952/motion-induced-position-shifts-activate-early-visual-cortex
#6
Peter J Kohler, Patrick Cavanagh, Peter U Tse
The ability to correctly determine the position of objects in space is a fundamental task of the visual system. The perceived position of briefly presented static objects can be influenced by nearby moving contours, as demonstrated by various illusions collectively known as motion-induced position shifts. Here we use a stimulus that produces a particularly strong effect of motion on perceived position. We test whether several regions-of-interest (ROIs), at different stages of visual processing, encode the perceived rather than retinotopically veridical position...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28416597/posterior-inferotemporal-cortex-cells-use-multiple-input-pathways-for-shape-encoding
#7
Carlos R Ponce, Stephen G Lomber, Margaret S Livingstone
In the macaque monkey brain, posterior inferior temporal cortex (PIT) cells contribute to visual object recognition. They receive concurrent inputs from visual areas V4, V3 and V2. We asked how these different anatomical pathways shape PIT response properties by deactivating them while monitoring PIT activity in two male macaques. We found that cooling of V4 or V2|3 did not lead to consistent changes in population excitatory drive, however, population pattern analyses showed that V4-based pathways were more important than V2|3-based pathways...
April 17, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28415897/electric-field-navigated-transcranial-magnetic-stimulation-for-chronic-tinnitus-a-randomized-placebo-controlled-study
#8
Hanna Sahlsten, Juuso Virtanen, Juho Joutsa, Katri Niinivirta-Joutsa, Eliisa Löyttyniemi, Reijo Johansson, Janika Paavola, Tero Taiminen, Noora Sjösten, Jaakko Salonen, Anu Holm, Esa Rauhala, Satu K Jääskeläinen
OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) may alleviate tinnitus. We evaluated effects of electric field (E-field) navigated rTMS targeted according to tinnitus pitch. No controlled studies have investigated anatomically accurate E-field-rTMS for tinnitus. DESIGN: Effects of E-field-rTMS were evaluated in a prospective randomised placebo-controlled 6-month follow-up study on parallel groups. Patients received 10 sessions of 1 Hz rTMS or placebo targeted to the left auditory cortex corresponding to tonotopic representation of tinnitus pitch...
April 18, 2017: International Journal of Audiology
https://www.readbyqxmd.com/read/28408869/rapid-long-range-disynaptic-inhibition-explains-the-formation-of-cortical-orientation-maps
#9
Ján Antolík
Competitive interactions are believed to underlie many types of cortical processing, ranging from memory formation, attention and development of cortical functional organization (e.g., development of orientation maps in primary visual cortex). In the latter case, the competitive interactions happen along the cortical surface, with local populations of neurons reinforcing each other, while competing with those displaced more distally. This specific configuration of lateral interactions is however in stark contrast with the known properties of the anatomical substrate, i...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28408865/tau-pathology-distribution-in-alzheimer-s-disease-corresponds-differentially-to-cognition-relevant-functional-brain-networks
#10
Oskar Hansson, Michel J Grothe, Tor Olof Strandberg, Tomas Ohlsson, Douglas Hägerström, Jonas Jögi, Ruben Smith, Michael Schöll
Neuropathological studies have shown that the typical neurofibrillary pathology of hyperphosphorylated tau protein in Alzheimer's disease (AD) preferentially affects specific brain regions whereas others remain relatively spared. It has been suggested that the distinct regional distribution profile of tau pathology in AD may be a consequence of the intrinsic network structure of the human brain. The spatially distributed brain regions that are most affected by the spread of tau pathology may hence reflect an interconnected neuronal system...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28405186/color-representation-is-retinotopically-biased-but-locally-intermingled-in-mouse-v1
#11
Shuhei Aihara, Takashi Yoshida, Takayuki Hashimoto, Kenichi Ohki
Dichromatic vision is common in many mammals. However, color processing in the primary visual cortex (V1) of dichromatic mammals is relatively unknown compared to the trichromatic primates. In this study, we investigated the functional organization of color processing in mouse V1. The mouse retina has a graded expression pattern of two opsins along its dorsoventral axis. However, it is not clear whether and how this expression pattern is reflected in the cortical representation at local (several hundred microns) and areal (V1) level...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28404826/multi-sensory-coding-in-the-multiple-demand-regions-vibrotactile-task-information-is-coded-in-frontoparietal-cortex
#12
Alexandra Woolgar, Regine Zopf
At any given moment, our brains receive input from multiple senses. Successful behaviour depends on our ability to prioritise the most important information and ignore the rest. A multiple-demand (MD) network of frontal and parietal regions is thought to support this process by adjusting to code information that is currently relevant (Duncan 2010). Accordingly, the network is proposed to encode a range of different types of information, including perceptual stimuli, task rules, and responses, as needed for the current cognitive operation...
April 12, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28398563/studying-microstructure-and-microstructural-changes-in-plant-tissues-by-advanced-diffusion-magnetic-resonance-imaging-techniques
#13
Darya Morozov, Iris Tal, Odelia Pisanty, Eilon Shani, Yoram Cohen
As sessile organisms, plants must respond to the environment by adjusting their growth and development. Most of the plant body is formed post-embryonically by continuous activity of apical and lateral meristems. The development of lateral adventitious roots is a complex process, and therefore the development of methods that can visualize, non-invasively, the plant microstructure and organ initiation that occur during growth and development is of paramount importance. In this study, relaxation-based and advanced diffusion magnetic resonance imaging (MRI) methods including diffusion tensor (DTI), q-space diffusion imaging (QSI), and double-pulsed-field-gradient (d-PFG) MRI, at 14...
April 8, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28396883/intracortical-circuits-in-thalamorecipient-layers-of-auditory-cortex-refine-after-visual-deprivation
#14
Xiangying Meng, Joseph P Y Kao, Hey-Kyoung Lee, Patrick O Kanold
Sensory cortices do not work in isolation. The functional responses of neurons in primary sensory cortices can be affected by activity from other modalities. For example, short-term visual deprivations, or dark exposure (DE), leads to enhanced neuronal responses and frequency selectivity to sounds in layer 4 (L4) of primary auditory cortex (A1). Circuit changes within A1 likely underlie these changes. Prior studies revealed that DE enhanced thalamocortical transmission to L4 in A1. Because the frequency selectivity of L4 neurons is determined by both thalamocortical and intracortical inputs, changes in intralaminar circuits to L4 neurons might also contribute to improved sound responses...
March 2017: ENeuro
https://www.readbyqxmd.com/read/28395730/emergence-of-transformation-tolerant-representations-of-visual-objects-in-rat-lateral-extrastriate-cortex
#15
Sina Tafazoli, Houman Safaai, Gioia De Franceschi, Federica Bianca Rosselli, Walter Vanzella, Margherita Riggi, Federica Buffolo, Stefano Panzeri, Davide Zoccolan
Rodents are emerging as increasingly popular models of visual functions. Yet, evidence that rodent visual cortex is capable of advanced visual processing, such as object recognition, is limited. Here we investigate how neurons located along the progression of extrastriate areas that, in the rat brain, run laterally to primary visual cortex, encode object information. We found a progressive functional specialization of neural responses along these areas, with: (1) a sharp reduction of the amount of low-level, energy-related visual information encoded by neuronal firing; and (2) a substantial increase in the ability of both single neurons and neuronal populations to support discrimination of visual objects under identity-preserving transformations (e...
April 11, 2017: ELife
https://www.readbyqxmd.com/read/28394230/advanced-mri-techniques-biomarkers-in-neuropsychiatric-lupus
#16
N Sarbu, P Toledano, A Calvo, E Roura, M I Sarbu, G Espinosa, X Lladó, R Cervera, N Bargalló
Objectives The objective of this study was to determine whether advanced MRI could provide biomarkers for diagnosis and prognosis in neuropsychiatric systemic lupus erythematosus (NPSLE). Methods Our prospective study included 28 systemic lupus erythematosus (SLE) patients with primary central NPSLE, 22 patients without NPSLE and 20 healthy controls. We used visual scales to evaluate atrophy and white matter hyperintensities, voxel-based morphometry and Freesurfer to measure brain volume, plus diffusion-tensor imaging (DTI) to assess white matter (WM) and gray matter (GM) damage...
April 2017: Lupus
https://www.readbyqxmd.com/read/28392326/preliminary-investigation-of-pain-related-changes-in-cerebral-blood-volume-in-patients-with-phantom-limb-pain
#17
Cheong Hoon Seo, Chang-Hyun Park, Myung Hun Jung, Soyeon Jang, So Young Joo, Yoonkyeong Kang, Suk Hoon Ohn
OBJECTIVE: We utilized MRI to measure CBV in patients who had undergone unilateral arm amputation following electrical injury to investigate changes in the pain network associated with phantom limb pain. DESIGN: Case-controlled exploratory MRI study of cerebral blood volume (CBV) via magnetic resonance imaging (MRI) SETTING: University hospital PARTICIPANTS: Ten patients with phantom limb pain following unilateral arm amputation and 16 healthy, age-matched participants...
April 6, 2017: Archives of Physical Medicine and Rehabilitation
https://www.readbyqxmd.com/read/28389743/a-biological-blueprint-for-the-axons-of-superficial-layer-pyramidal-cells-in-cat-primary-visual-cortex
#18
Kevan A C Martin, Stephan Roth, Elisha S Rusch
Pyramidal cells in the superficial layers of neocortex of higher mammals form a lateral network of axon clusters known as the 'daisy' network. The role of these axon clusters remains speculative and we still lack a comprehensive quantitative description of the single neurons forming the daisy or their heterogeneity. We filled intracellularly 50 superficial layer pyramidal neurons in the cat primary visual cortex and reconstructed the axonal tree and their synaptic boutons in 3D. Individual bouton clusters were identified using an objective mean-shift algorithm...
April 7, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28389384/correspondence-between-fmri-and-electrophysiology-during-visual-motion-processing-in-human-mt
#19
Anna Gaglianese, Mariska J Vansteensel, Ben M Harvey, Serge O Dumoulin, Natalia Petridou, Nick F Ramsey
Changes in brain neuronal activity are reflected by hemodynamic responses mapped through Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI), a primary tool to measure brain functioning non-invasively. However, the exact relationship between hemodynamics and neuronal function is still a matter of debate. Here, we combine 3T BOLD fMRI and High Frequency Band (HFB) electrocorticography (ECoG) signals to investigate the relationship between neuronal activity and hemodynamic responses in the human Middle Temporal complex (hMT+), a higher order brain area involved in visual motion processing...
April 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28385875/correlates-of-perceptual-orientation-biases-in-human-primary-visual-cortex
#20
Matthew L Patten, Damien J Mannion, Colin W G Clifford
Vision can be considered as a process of probabilistic inference. In a Bayesian framework, perceptual estimates from sensory information are combined with prior knowledge, with a stronger influence of the prior when the sensory evidence is less certain. Here, we explored the behavioral and neural consequences of manipulating stimulus certainty in the context of orientation processing. First, we asked participants to judge whether a stimulus was oriented closer to vertical or the clockwise primary oblique (45°) for two stimulus types (spatially-filtered noise textures, sinusoidal gratings) and three manipulations of certainty (orientation bandwidth, contrast, duration)...
April 6, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
keyword
keyword
54569
1
2
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"