scholarly journals Lateral phase differences in a population model of the visual cortex are sufficient for the development of rhythmic spatial sampling

2020 ◽  
Author(s):  
Justin D. Yi ◽  
Katsushi Arisaka
Keyword(s):  
Visual Cortex ◽  
Spatial Attention ◽  
Phase Difference ◽  
Computational Study ◽  
Field Potential ◽  
Low Frequency ◽  
Probability Of Detection ◽  
Population Activity ◽  
Attention Task ◽  
Phase Differences

AbstractWhen attending to many spatially distributed visual stimuli, attention is reweighted rhythmically at 4-8 Hz. The probability of detection depends on the phase at which a stimulus is deployed relative to this intrinsic rhythm. The reweighting oscillations can be observed both electrophysiologically and behaviorally, and appear to be regulated by the pulvinar. Based on these findings, we considered the computational consequences of allowing feedback to shape the distribution of inhibitory oscillations from the thalamus, as measured by a local field potential (LFP) phases in the 8 Hz low alpha-band, across laterally-connected regions of the visual cortex. We constructed a population activity model with lateral and feedforward connections. In agreement with prior models, we found that the sign of the lateral phase difference in the inhibitory low-frequency oscillations regulated the direction of communication between the laterally-connected regions. Furthermore, the phase difference induced periodicity in the dynamics of a downstream winner-takes-all attractor network such that periodic switching between states was observed. We finally simulated a simple spatial attention task. We found rhythmic 8 Hz sampling between two regions when a lateral phase difference was present—an effect that disappeared when the lateral phase difference was zero. These findings are in agreement with spatial attention literature and suggest that lateral phase differences are essential for manifesting communicational asymmetries in laterally-connected visual cortices. Our model predicts that population-specific phase differences are critical for sampling the spatial extent of stimuli.Author summaryWe conducted a computational study of the effects of lateral phase differences in a simulated model of the visual cortex. Lateral phase differences are defined to be when the phase of an intrinsic low-frequency inhibitory oscillation varies consistently across populations in the same cortical area. For example, our model was intended to capture the dynamics of a retinotopic cortex where feedback from the frotoparietal areas via the pulvinar nucleus assigned laterally-connected regions of the visual cortex different phases. We found that the sign of the phase differences influenced the direction of lateral communication. Furthermore, the phase differences introduced rhythmicity in the downstream areas, thus allowing us to simulate rhythmic spatial selection of stimuli. Prior to the current study, the influence of inter-areal phase differences in feedforward models had been well characterized. Our model provides new insights into the dynamics of population-specific lateral phase differences and predicts that the development of phase differences across the visual cortex are critical for the allocation of attention in space.

scholarly journals Laminar dependence of neuronal correlations in visual cortex

2013 ◽  
Vol 109 (4) ◽  
pp. 940-947 ◽  
Author(s):  
Matthew A. Smith ◽  
Xiaoxuan Jia ◽  
Amin Zandvakili ◽  
Adam Kohn
Keyword(s):  
Visual Cortex ◽  
Field Potential ◽  
Low Frequency ◽  
Population Coding ◽  
Neuronal Responses ◽  
Cortical Function ◽  
Area V2 ◽  
Complementary Pattern ◽  
Deep Layers ◽  
Slow Timescale

Neuronal responses are correlated on a range of timescales. Correlations can affect population coding and may play an important role in cortical function. Correlations are known to depend on stimulus drive, behavioral context, and experience, but the mechanisms that determine their properties are poorly understood. Here we make use of the laminar organization of cortex, with its variations in sources of input, local circuit architecture, and neuronal properties, to test whether networks engaged in similar functions but with distinct properties generate different patterns of correlation. We find that slow timescale correlations are prominent in the superficial and deep layers of primary visual cortex (V1) of macaque monkeys, but near zero in the middle layers. Brief timescale correlation (synchrony), on the other hand, was slightly stronger in the middle layers of V1, although evident at most cortical depths. Laminar variations were also apparent in the power of the local field potential, with a complementary pattern for low frequency (<10 Hz) and gamma (30–50 Hz) power. Recordings in area V2 revealed a laminar dependence similar to V1 for synchrony, but slow timescale correlations were not different between the input layers and nearby locations. Our results reveal that cortical circuits in different laminae can generate remarkably different patterns of correlations, despite being tightly interconnected.

scholarly journals Induced cortical oscillations in turtle cortex are coherent at the mesoscale of population activity, but not at the microscale of the membrane potential of neurons

2017 ◽  
Vol 118 (5) ◽  
pp. 2579-2591 ◽  
Author(s):  
Mahmood S. Hoseini ◽  
Jeff Pobst ◽  
Nathaniel Wright ◽  
Wesley Clawson ◽  
Woodrow Shew ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Membrane Potential ◽  
Neural Activity ◽  
Visual Stimulation ◽  
Field Potential ◽  
Brain Regions ◽  
Large Trial ◽  
Population Activity ◽  
Potential Oscillations ◽  
Time Frequency

Bursts of oscillatory neural activity have been hypothesized to be a core mechanism by which remote brain regions can communicate. Such a hypothesis raises the question to what extent oscillations are coherent across spatially distant neural populations. To address this question, we obtained local field potential (LFP) and membrane potential recordings from the visual cortex of turtle in response to visual stimulation of the retina. The time-frequency analysis of these recordings revealed pronounced bursts of oscillatory neural activity and a large trial-to-trial variability in the spectral and temporal properties of the observed oscillations. First, local bursts of oscillations varied from trial to trial in both burst duration and peak frequency. Second, oscillations of a given recording site were not autocoherent; i.e., the phase did not progress linearly in time. Third, LFP oscillations at spatially separate locations within the visual cortex were more phase coherent in the presence of visual stimulation than during ongoing activity. In contrast, the membrane potential oscillations from pairs of simultaneously recorded pyramidal neurons showed smaller phase coherence, which did not change when switching from black screen to visual stimulation. In conclusion, neuronal oscillations at distant locations in visual cortex are coherent at the mesoscale of population activity, but coherence is largely absent at the microscale of the membrane potential of neurons. NEW & NOTEWORTHY Coherent oscillatory neural activity has long been hypothesized as a potential mechanism for communication across locations in the brain. In this study we confirm the existence of coherent oscillations at the mesoscale of integrated cortical population activity. However, at the microscopic level of neurons, we find no evidence for coherence among oscillatory membrane potential fluctuations. These results raise questions about the applicability of the communication through coherence hypothesis to the level of the membrane potential.

scholarly journals Modulation of intracranial field potential responses in the human large-scale attention network during a spatial attention task

2015 ◽  
Vol 15 (12) ◽  
pp. 1055
Author(s):  
Anne Martin ◽  
Liang Wang ◽  
Yuri Saalmann ◽  
Avgusta Shestyuk ◽  
Su Keun Jeong ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Large Scale ◽  
Field Potential ◽  
Attention Task ◽  
Attention Network

scholarly journals Cholinergic manipulations affect sensory responses but not attentional enhancement in macaque MT

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Vera Katharina Veith ◽  
Cliodhna Quigley ◽  
Stefan Treue
Keyword(s):  
Visual Cortex ◽  
Spatial Attention ◽  
Rhesus Monkeys ◽  
Cell Activity ◽  
Extrastriate Cortex ◽  
Attentional Modulation ◽  
Cellular Mechanisms ◽  
Attention Task ◽  
Sensory Responses ◽  
Cholinergic Effect

Abstract Background Attentional modulation in the visual cortex of primates is characterized by multiplicative changes of sensory responses with changes in the attentional state of the animal. The cholinergic system has been linked to such gain changes in V1. Here, we aim to determine if a similar link exists in macaque area MT. While rhesus monkeys performed a top-down spatial attention task, we locally injected a cholinergic agonist or antagonist and recorded single-cell activity. Results Although we confirmed cholinergic influences on sensory responses, there was no additional cholinergic effect on the attentional gain changes. Neither a muscarinic blockage nor a local increase in acetylcholine led to a significant change in the magnitude of spatial attention effects on firing rates. Conclusions This suggests that the cellular mechanisms of attentional modulation in the extrastriate cortex cannot be directly inferred from those in the primary visual cortex.

scholarly journals Visual recognition is heralded by shifts in local field potential oscillations and inhibitory networks in primary visual cortex

2020 ◽  
Author(s):  
Dustin J. Hayden ◽  
Daniel P. Montgomery ◽  
Samuel F. Cooke ◽  
Mark F. Bear
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Local Field ◽  
High Frequency ◽  
Peak Power ◽  
Field Potential ◽  
Low Frequency ◽  
Inhibitory Neurons ◽  
Stimulus Familiarity ◽  
Frequency Power

AbstractFiltering out familiar, irrelevant stimuli eases the computational burden on the cerebral cortex. Inhibition is a candidate mechanism in this filtration process. Oscillations in the cortical local field potential (LFP) serve as markers of the engagement of different inhibitory neurons. In awake mice, we find pronounced changes in LFP oscillatory activity present in layer 4 of primary visual cortex (V1) with progressive stimulus familiarity. Over days of repeated stimulus presentation, low frequency (alpha/beta ~15 Hz peak) power increases while high frequency (gamma ~65 Hz peak) power decreases. This high frequency activity re-emerges when a novel stimulus is shown. Thus, high frequency power is a marker of novelty while low frequency power signifies familiarity. Two-photon imaging of neuronal activity reveals that parvalbumin-expressing inhibitory neurons disengage with familiar stimuli and reactivate to novelty, consistent with their known role in gamma oscillations, whereas somatostatin-expressing inhibitory neurons show opposing activity patterns, indicating a contribution to the emergence of lower frequency oscillations. We also reveal that stimulus familiarity and novelty have differential effects on oscillations and cell activity over a shorter timescale of seconds. Taken together with previous findings, we propose a model in which two interneuron circuits compete to drive familiarity or novelty encoding.

scholarly journals Frequency-separated principal component analysis of cortical population activity

2020 ◽  
Vol 124 (3) ◽  
pp. 668-681
Author(s):  
Jean-Philippe Thivierge
Keyword(s):  
Principal Component Analysis ◽  
Visual Cortex ◽  
Sensory Input ◽  
Low Frequency ◽  
Principal Component ◽  
Component Analysis ◽  
Population Activity ◽  
Standard Principal Component Analysis ◽  
Specific Frequency ◽  
Low Dimensional

A method termed frequency-separated principal component analysis (FS-PCA) is introduced for analyzing populations of simultaneously recorded neurons. This framework extends standard principal component analysis by extracting components of activity delimited to specific frequency bands. FS-PCA revealed that circuits of the primary visual cortex generate a broad range of components dominated by low-frequency activity. Furthermore, low-dimensional fluctuations in population activity modulated the response of individual neurons to sensory input.

scholarly journals An Interneuron Circuit Reproducing Essential Spectral Features of Field Potentials

2018 ◽  
Vol 30 (5) ◽  
pp. 1296-1322 ◽  
Author(s):  
Reinoud Maex
Keyword(s):  
Computational Study ◽  
Electrical Coupling ◽  
Field Potential ◽  
Low Frequency ◽  
Reciprocal Inhibition ◽  
Mammalian Brain ◽  
Power Scaling ◽  
Field Potentials ◽  
Neuronal Synchrony ◽  
Α Rhythm

Recent advances in engineering and signal processing have renewed the interest in invasive and surface brain recordings, yet many features of cortical field potentials remain incompletely understood. In the computational study that follows, we show that a model circuit of interneurons, coupled via both GABAA receptor synapses and electrical synapses, reproduces many essential features of the power spectrum of local field potential (LFP) recordings, such as 1/ f power scaling at low frequency (below 10 Hz), power accumulation in the γ-frequency band (30–100 Hz), and a robust α rhythm in the absence of stimulation. The low-frequency 1/ f power scaling depends on strong reciprocal inhibition, whereas the α rhythm is generated by electrical coupling of intrinsically active neurons. As in previous studies, the γ power arises through the amplification of single-neuron spectral properties, owing to the refractory period, by parameters that favor neuronal synchrony, such as delayed inhibition. This study also confirms that both synaptic and voltage-gated membrane currents contribute substantially to the LFP and that high-frequency signals such as action potentials quickly taper off with distance. Given the ubiquity of electrically coupled interneuron circuits in the mammalian brain, they may be major determinants of the recorded potentials.

Service Area Calibration of Hyperbolic Navigation Systems

1963 ◽  
Vol 16 (2) ◽  
pp. 227-242
Author(s):  
Joseph E. Sullivan ◽  
William A. Porter
Keyword(s):  
Phase Difference ◽  
Research Group ◽  
Science And Technology ◽  
Low Frequency ◽  
Assistant Professor ◽  
Service Area ◽  
Mathematical Treatment ◽  
Navigation Systems ◽  
Position Information ◽  
Phase Differences

It is well known that in low-frequency hyperbolic navigational systems the phase differences measured by the receiver do not correspond precisely to the hyperbolas on the plotting chart. This is largely because of variations in the terrain over which the waves are propagated. The system service area may be sampled so that the curve distortions can be ascertained at selected points. This article discusses how the whole service area can be calibrated, given a knowledge of the grid distortions at a sample of points. The mathematical treatment takes into account the correlation between the grid distortions at adjacent sampling points by using autocorrelation theory.The degree to which fixing accuracy is improved by the proposed method of calibration is assessed against the background of an actual set of field measurements.Mr. Sullivan is Head of the Applied Research Group of the Navigation and Guidance Laboratory at the Institute of Science and Technology. Dr. Porter is Assistant Professor of Electrical Engineering at The University of Michigan, and Head, Analytical Research Group of Navigation and Guidance Laboratory at the Institute of Science and Technology.In low-frequency ground-wave navigation systems such as Loran-C and Decca, position information is determined from measurements of time and/or phase differences in signals received from several separately located transmitter stations. A pair of stations generates a family of hyperbolic lines which are the loci of points of constant time/phase difference. Two station pairs provide a grid of hyperbolas. By measurement of the time/phase difference between the signals from two transmitters, the receiver is located on a hyperbolic line. The same receiver is located on a second line by similar measurement which uses another pair of stations; the receiver is thus fixed specifically at the intersection of the two lines.

Visual Spatial Attention in Migraine Sufferers in Postictal and Interictal Phases: An Event-Related Potential Study

2001 ◽  
Vol 15 (1) ◽  
pp. 22-34 ◽  
Author(s):  
D.H. de Koning ◽  
J.C. Woestenburg ◽  
M. Elton
Keyword(s):  
Cerebral Cortex ◽  
Visual Attention ◽  
Migraine Attack ◽  
Spatial Attention ◽  
Event Related Potential ◽  
Significant Enhancement ◽  
Pathophysiological Mechanism ◽  
Attention Task ◽  
Visual Spatial Attention ◽  
Visual Spatial

Migraineurs with and without aura (MWAs and MWOAs) as well as controls were measured twice with an interval of 7 days. The first session of recordings and tests for migraineurs was held about 7 hours after a migraine attack. We hypothesized that electrophysiological changes in the posterior cerebral cortex related to visual spatial attention are influenced by the level of arousal in migraineurs with aura, and that this varies over the course of time. ERPs related to the active visual attention task manifested significant differences between controls and both types of migraine sufferers for the N200, suggesting a common pathophysiological mechanism for migraineurs. Furthermore, migraineurs without aura (MWOAs) showed a significant enhancement for the N200 at the second session, indicating the relevance of time of measurement within migraine studies. Finally, migraineurs with aura (MWAs) showed significantly enhanced P240 and P300 components at central and parietal cortical sites compared to MWOAs and controls, which seemed to be maintained over both sessions and could be indicative of increased noradrenergic activity in MWAs.

Sign in / Sign up

Export Citation Format

Share Document