scholarly journals Direct comparison of population receptive fields from fMRI and large-scale neurophysiological recordings in awake non-human primates

2020 ◽  
Author(s):  
P. Christiaan Klink ◽  
Xing Chen ◽  
Wim Vanduffel ◽  
Pieter R. Roelfsema
Keyword(s):  
Large Scale ◽  
Receptive Fields ◽  
Field Potential ◽  
Spatial Summation ◽  
Network Nodes ◽  
Retinotopic Organization ◽  
Neuronal Signal ◽  
Distinct Frequency ◽  
Neural Underpinnings ◽  
Brain Fmri

AbstractPopulation receptive field (pRF) modeling is a popular method to map the retinotopic organization of the human brain with fMRI. While BOLD-based pRF-maps are qualitatively similar to invasively recorded single-cell receptive fields in animals, it remains unclear what neuronal signal they truly represent. We address this question with whole-brain fMRI and large-scale neurophysiological recordings in awake non-human primates. Several pRF-models were independently fit to the BOLD signal, multi-unit spiking activity (MUA) and local field potential (LFP) power in distinct frequency bands. Our results provide a retinotopic characterization of cortical and subcortical areas, suggest brain-wide compressive (i.e., sublinear) spatial summation, and demonstrate a visually tuned deactivation of default mode network nodes. Cross-signal analysis of pRF-map structure (eccentricity-size relation) indicates that the neural underpinnings of BOLD-pRFs are area-specific. In V1, BOLD-pRFs mirror MUA, while in V4 they are more similar to the tuning of the gamma LFP-power.

scholarly journals Population receptive fields in non-human primates from whole-brain fMRI and large-scale neurophysiology in visual cortex in visual cortex

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Peter Christiaan Klink ◽  
Xing Chen ◽  
Vim Vanduffel ◽  
Pieter Roelfsema
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Large Scale ◽  
Receptive Fields ◽  
Field Potential ◽  
Whole Brain ◽  
Network Nodes ◽  
Gamma Power ◽  
Retinotopic Organization ◽  
Brain Fmri

Population receptive field (pRF) modeling is a popular fMRI method to map the retinotopic organization of the human brain. While fMRI-based pRF-maps are qualitatively similar to invasively recorded single-cell receptive fields in animals, it remains unclear what neuronal signal they represent. We addressed this question in awake non-human primates comparing whole-brain fMRI and large-scale neurophysiological recordings in areas V1 and V4 of the visual cortex. We examined the fits of several pRF-models based on the fMRI BOLD-signal, multi-unit spiking activity (MUA) and local field potential (LFP) power in different frequency bands. We found that pRFs derived from BOLD-fMRI were most similar to MUA-pRFs in V1 and V4, while pRFs based on LFP gamma power also gave a good approximation. FMRI-based pRFs thus reliably reflect neuronal receptive field properties in the primate brain. In addition to our results in V1 and V4, the whole-brain fMRI measurements revealed retinotopic tuning in many other cortical and subcortical areas with a consistent increase in pRF-size with increasing eccentricity, as well as a retinotopically specific deactivation of default-mode network nodes similar to previous observations in humans.

scholarly journals Hierarchical Timescales in the Neocortex: Mathematical Mechanism and Biological Insights

2021 ◽  
Author(s):  
Songting Li ◽  
Xiao-Jing Wang
Keyword(s):  
Large Scale ◽  
Detailed Balance ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Progressive Increase ◽  
Connectivity Matrix ◽  
Electrophysiological Properties ◽  
Neuronal Populations ◽  
Sensory Neural ◽  
Experimental Findings

A cardinal feature of the neocortex is the progressive increase of the spatial receptive fields along the cortical hierarchy. Recently, theoretical and experimental findings have shown that the temporal response windows also gradually enlarge, so that early sensory neural circuits operate on short-time scales whereas higher association areas are capable of integrating information over a long period of time. While an increased receptive field is accounted for by spatial summation of inputs from neurons in an upstream area, the emergence of timescale hierarchy cannot be readily explained, especially given the dense inter-areal cortical connectivity known in modern connectome. To uncover the required neurobiological properties, we carried out a rigorous analysis of an anatomically-based large-scale cortex model of macaque monkeys. Using a perturbation method, we show that the segregation of disparate timescales is defined in terms of the localization of eigenvectors of the connectivity matrix, which depends on three circuit properties: (1) a macroscopic gradient of synaptic excitation, (2) distinct electrophysiological properties between excitatory and inhibitory neuronal populations, and (3) a detailed balance between long-range excitatory inputs and local inhibitory inputs for each area-to-area pathway. Our work thus provides a quantitative understanding of the mechanism underlying the emergence of timescale hierarchy in large-scale primate cortical networks.

Component analysis reveals sharp tuning of the local field potential in the guinea pig auditory cortex

2013 ◽  
Vol 109 (1) ◽  
pp. 261-272 ◽  
Author(s):  
Alain de Cheveigné ◽  
Jean-Marc Edeline ◽  
Quentin Gaucher ◽  
Boris Gourévitch
Keyword(s):  
Auditory Cortex ◽  
Local Field ◽  
Receptive Fields ◽  
Field Potential ◽  
Component Analysis ◽  
Electrode Arrays ◽  
Linear Combinations ◽  
Spectrotemporal Receptive Fields ◽  
Analysis Technique ◽  
Channel Electrode

Local field potentials (LFPs) recorded in the auditory cortex of mammals are known to reveal weakly selective and often multimodal spectrotemporal receptive fields in contrast to spiking activity. This may in part reflect the wider “listening sphere” of LFPs relative to spikes due to the greater current spread at low than high frequencies. We recorded LFPs and spikes from auditory cortex of guinea pigs using 16-channel electrode arrays. LFPs were processed by a component analysis technique that produces optimally tuned linear combinations of electrode signals. Linear combinations of LFPs were found to have sharply tuned responses, closer to spike-related tuning. The existence of a sharply tuned component implies that a cortical neuron (or group of neurons) capable of forming a linear combination of its inputs has access to that information. Linear combinations of signals from electrode arrays reveal information latent in the subspace spanned by multichannel LFP recordings and are justified by the fact that the observations themselves are linear combinations of neural sources.

Position Selectivity in Scene- and Object-Responsive Occipitotemporal Regions

2007 ◽  
Vol 98 (4) ◽  
pp. 2089-2098 ◽  
Author(s):  
Sean P. MacEvoy ◽  
Russell A. Epstein
Keyword(s):  
Large Scale ◽  
Scene Perception ◽  
Receptive Fields ◽  
Neural Responses ◽  
Retinal Position ◽  
Vertical Meridian ◽  
Retinal Stimulation ◽  
Natural Vision ◽  
Visual Hemifields ◽  
Insight Into

Complex visual scenes preferentially activate several areas of the human brain, including the parahippocampal place area (PPA), the retrosplenial complex (RSC), and the transverse occipital sulcus (TOS). The sensitivity of neurons in these regions to the retinal position of stimuli is unknown, but could provide insight into their roles in scene perception and navigation. To address this issue, we used functional magnetic resonance imaging (fMRI) to measure neural responses evoked by sequences of scenes and objects confined to either the left or right visual hemifields. We also measured the level of adaptation produced when stimuli were either presented first in one hemifield and then repeated in the opposite hemifield or repeated in the same hemifield. Although overall responses in the PPA, RSC, and TOS tended to be higher for contralateral stimuli than for ipsilateral stimuli, all three regions exhibited position-invariant adaptation, insofar as the magnitude of adaptation did not depend on whether stimuli were repeated in the same or opposite hemifields. In contrast, object-selective regions showed significantly greater adaptation when objects were repeated in the same hemifield. These results suggest that neuronal receptive fields (RFs) in scene-selective regions span the vertical meridian, whereas RFs in object-selective regions do not. The PPA, RSC, and TOS may support scene perception and navigation by maintaining stable representations of large-scale features of the visual environment that are insensitive to the shifts in retinal stimulation that occur frequently during natural vision.

Simultaneous Segmentation of Fetal Hearts and Lungs for Medical Ultrasound Images via an Efficient Multi-scale Model Integrated With Attention Mechanism

2021 ◽  
pp. 016173462110425
Author(s):  
Jianing Xi ◽  
Jiangang Chen ◽  
Zhao Wang ◽  
Dean Ta ◽  
Bing Lu ◽  
...  
Keyword(s):  
Congenital Anomaly ◽  
Large Scale ◽  
Automatic Segmentation ◽  
Receptive Fields ◽  
Semantic Segmentation ◽  
Attention Mechanism ◽  
Scale Model ◽  
Ultrasound Images ◽  
Multi Scale ◽  
Task Irrelevant

Large scale early scanning of fetuses via ultrasound imaging is widely used to alleviate the morbidity or mortality caused by congenital anomalies in fetal hearts and lungs. To reduce the intensive cost during manual recognition of organ regions, many automatic segmentation methods have been proposed. However, the existing methods still encounter multi-scale problem at a larger range of receptive fields of organs in images, resolution problem of segmentation mask, and interference problem of task-irrelevant features, obscuring the attainment of accurate segmentations. To achieve semantic segmentation with functions of (1) extracting multi-scale features from images, (2) compensating information of high resolution, and (3) eliminating the task-irrelevant features, we propose a multi-scale model with skip connection framework and attention mechanism integrated. The multi-scale feature extraction modules are incorporated with additive attention gate units for irrelevant feature elimination, through a U-Net framework with skip connections for information compensation. The performance of fetal heart and lung segmentation indicates the superiority of our method over the existing deep learning based approaches. Our method also shows competitive performance stability during the task of semantic segmentations, showing a promising contribution on ultrasound based prognosis of congenital anomaly in the early intervention, and alleviating the negative effects caused by congenital anomaly.

scholarly journals Functional Brain Connectivity Revealed by Sparse Coding of Large-Scale Local Field Potential Dynamics

2018 ◽  
Vol 32 (2) ◽  
pp. 255-270 ◽  
Author(s):  
Han Wang ◽  
Kun Xie ◽  
Li Xie ◽  
Xiang Li ◽  
Meng Li ◽  
...  
Keyword(s):  
Local Field ◽  
Sparse Coding ◽  
Local Field Potential ◽  
Large Scale ◽  
Brain Connectivity ◽  
Field Potential ◽  
Functional Brain

scholarly journals Google matrix analysis of worldwide football mercato

2018 ◽  
Author(s):  
José Lages ◽  
Justin Loye ◽  
Célestin Coquidé ◽  
Guillaume Rollin
Keyword(s):  
Large Scale ◽  
World Wide ◽  
Matrix Analysis ◽  
Two Dimensional ◽  
Network Nodes ◽  
Pagerank Algorithm ◽  
Google Matrix ◽  
Football Clubs ◽  
The World ◽  
Different Types

The worldwide football transfer market is analyzed as a directed complex network: the football clubs are the network nodes and the directed edges are weighted by the total amount of money transferred from a club to another. The Google matrix description allows to treat every club independently of their richness and allows to measure for a given club the efficiency of player sales and player acquisitions. The PageRank algorithm, developed initially for the World Wide Web, naturally characterizes the ability of a club to import players. The CheiRank algorithm, also developed to analyze large scale directed complex networks, characterizes the ability of a club to export players. The analysis in the two-dimensional PageRank-CheiRank plan permits to determine the transfer balance of the clubs in a more subtle manner than the traditional import-export scheme. We investigate the 2017-2018 mercato concerning 2296 clubs, 6698 player transfers, and 147 player nationalities. The transfer balance is determined globally for different types of player trades (defender, midfielder, forward, …) and for different national football leagues. Although, on average, the network transfer flows from and to clubs are balanced, the discrimination by player type draws a specific portrait of each football club.

scholarly journals Attention operates uniformly throughout the classical receptive field and the surround

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Bram-Ernst Verhoef ◽  
John HR Maunsell
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Field Structure ◽  
Neuronal Responses ◽  
Large Variability ◽  
Area V4 ◽  
Classical Receptive Field ◽  
Spatially Varying

Shifting attention among visual stimuli at different locations modulates neuronal responses in heterogeneous ways, depending on where those stimuli lie within the receptive fields of neurons. Yet how attention interacts with the receptive-field structure of cortical neurons remains unclear. We measured neuronal responses in area V4 while monkeys shifted their attention among stimuli placed in different locations within and around neuronal receptive fields. We found that attention interacts uniformly with the spatially-varying excitation and suppression associated with the receptive field. This interaction explained the large variability in attention modulation across neurons, and a non-additive relationship among stimulus selectivity, stimulus-induced suppression and attention modulation that has not been previously described. A spatially-tuned normalization model precisely accounted for all observed attention modulations and for the spatial summation properties of neurons. These results provide a unified account of spatial summation and attention-related modulation across both the classical receptive field and the surround.

Directional filter characteristics of optic nerve fibers in California ground squirrel (Spermophilus beecheyi)

1984 ◽  
Vol 52 (6) ◽  
pp. 1200-1212 ◽  
Author(s):  
M. E. McCourt ◽  
G. H. Jacobs
Keyword(s):  
Optic Nerve ◽  
Ground Squirrel ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Nerve Fibers ◽  
Field Size ◽  
Image Motion ◽  
Spermophilus Beecheyi ◽  
California Ground Squirrel ◽  
Preferred Direction

Directional units in the optic nerve of the California ground squirrel (Spermophilus beecheyi) were studied with respect to their response to diffuse light, preferred directions of motion, tuning for preferred direction, the relationship between spatial and directional tuning characteristics, and receptive-field size and areal summating properties. Directional units in the ground squirrel optic nerve are of the “on-off” type. No purely on or off units were encountered in a sample of 356 directionally selective fibers. The distribution of preferred directions of image motion for 356 units was significantly anisotropic; greater than 50% of the directional units prefer motion in the direction of the superior-nasal visual quadrant. Mean directional bandwidth, measured at half-amplitude response, for 39 units was 88.5 degrees. The distribution of directional bandwidths suggests that two subpopulations of directional units may exist a broadly tuned (106.4 degrees bandwidth) group preferring image motion in the superior-nasal direction, and a narrowly tuned group (59.9 degrees bandwidth) with a uniform distribution of preferred direction. Tuning for direction of motion and for spatial frequency were significantly positively correlated in a sample of 35 directional units. Area-vs.-response measures for directional units show that they possess excitatory discharge centers with a concentric antagonistic surround, plus a larger suppressive surround activated specifically by moving luminance contours, which may be asymmetric. Critical activation areas for directional units, as measured along orthogonal orientations, were highly positively correlated. This suggests that these receptive fields possess the property of linear spatial summation, not of luminance flux, but of areas of moving luminance contours.

Sign in / Sign up

Export Citation Format

Share Document