Unnamed: 0 int64 0 41k | title stringlengths 4 274 | category stringlengths 5 18 | summary stringlengths 22 3.66k | theme stringclasses 8
values |
|---|---|---|---|---|
5,200 | Synchronization and oscillatory dynamics in heterogeneous mutually inhibited neurons | q-bio.NC | We study some mechanisms responsible for synchronous oscillations and loss of
synchrony at physiologically relevant frequencies (10-200 Hz) in a network of
heterogeneous inhibitory neurons. We focus on the factors that determine the
level of synchrony and frequency of the network response, as well as the
effects of mil... | biology |
5,201 | Frequency control in synchronized networks of inhibitory neurons | q-bio.NC | We analyze the control of frequency for a synchronized inhibitory neuronal
network. The analysis is done for a reduced membrane model with a
biophysically-based synaptic influence. We argue that such a reduced model can
quantitatively capture the frequency behavior of a larger class of neuronal
models. We show that in ... | biology |
5,202 | Coding Strategies in Monkey V1 and Inferior Temporal Cortices | q-bio.NC | We would like to know whether the statistics of neuronal responses vary
across cortical areas. We examined stimulus-elicited spike count response
distributions in V1 and IT cortices of awake monkeys. In both areas the
distribution of spike counts for each stimulus was well-described by a
Gaussian, with the log of the v... | biology |
5,203 | Measuring the dynamics of neural responses in primary auditory cortex | q-bio.NC | We review recent developments in the measurement of the dynamics of the
response properties of auditory cortical neurons to broadband sounds, which is
closely related to the perception of timbre. The emphasis is on a method that
characterizes the spectro-temporal properties of single neurons to dynamic,
broadband sound... | biology |
5,204 | Synaptic Transmission: An Information-Theoretic Perspective | q-bio.NC | Here we analyze synaptic transmission from an information-theoretic
perspective. We derive closed-form expressions for the lower-bounds on the
capacity of a simple model of a cortical synapse under two explicit coding
paradigms. Under the ``signal estimation'' paradigm, we assume the signal to be
encoded in the mean fi... | biology |
5,205 | Sensory Coding with Dynamically Competitive Networks | q-bio.NC | Studies of insect olfactory processing indicate that odors are represented by
rich spatio-temporal patterns of neural activity. These patterns are very
difficult to predict a priori, yet they are stimulus specific and reliable upon
repeated stimulation with the same input. We formulate here a theoretical
framework in w... | biology |
5,206 | Temporal structure in neuronal activity during working memory in Macaque parietal cortex | q-bio.NC | A number of cortical structures are reported to have elevated single unit
firing rates sustained throughout the memory period of a working memory task.
How the nervous system forms and maintains these memories is unknown but
reverberating neuronal network activity is thought to be important. We studied
the temporal str... | biology |
5,207 | Structured psychosocial stress and therapeutic failure | q-bio.NC | Generalized language-of-thought arguments appropriate to interacting
cognitive modules permit exploration of how disease states interact with
medical treatment. The interpenetrating feedback between treatment and response
to it creates a kind of idiotypic hall-of-mirrors generating a synergistic
pattern of efficacy, tr... | biology |
5,208 | Different ocular dominance map formation by influence of orientation columns in visual cortices | q-bio.NC | In animal experiments, the observed orientation preference (OP) and ocular
dominance (OD) columns in the visual cortex of the brain show various pattern
types. Here, we show that the different visual map formations in various
species are due to the crossover behavior in anisotropic systems composed of
orientational and... | biology |
5,209 | What do neural nets and quantum theory tell us about mind and reality? | q-bio.NC | This paper proposes an approach to framing and answering fundamental
questions about consciousness. It argues that many of the more theoretical
debates about consciousness, such as debates about "when does it begin?", are
misplaced and meaningless, in part because "consciousness" as a word has many
valid and interestin... | biology |
5,210 | Brain neurons as quantum computers: {\it in vivo} support of background physics | q-bio.NC | The question: whether quantum coherent states can sustain decoherence,
heating and dissipation over time scales comparable to the dynamical timescales
of the brain neurons, is actively discussed in the last years. Positive answer
on this question is crucial, in particular, for consideration of brain neurons
as quantum ... | biology |
5,211 | Ocular dominance patterns and the wire length minimization: a numerical study | q-bio.NC | We study a mathematical model for ocular dominance patterns (ODPs) in primary
visual cortex. This model is based on the premise that ODP is an adaptation to
minimize the length of intra-cortical wiring. Thus we attempt to understand the
existing ODPs by solving a wire length minimization problem. We divide all the
neur... | biology |
5,212 | Comparation based bottom-up and top-down filtering model of the hippocampus and its environment | q-bio.NC | Two rate code models -- a reconstruction network model and a control model --
of the hippocampal-entorhinal loop are merged. The hippocampal-entorhinal loop
plays a double role in the unified model, it is part of a reconstruction
network and a controller, too. This double role turns the bottom-up information
flow into ... | biology |
5,213 | Fast Computation with Neural Oscillators | q-bio.NC | Artificial spike-based computation, inspired by models of computations in the
central nervous system, may present significant performance advantages over
traditional methods for specific types of large scale problems. In this paper,
we study new models for two common instances of such computation,
winner-take-all and c... | biology |
5,214 | Random Walks for Spike-Timing Dependent Plasticity | q-bio.NC | Random walk methods are used to calculate the moments of negative image
equilibrium distributions in synaptic weight dynamics governed by spike-timing
dependent plasticity (STDP). The neural architecture of the model is based on
the electrosensory lateral line lobe (ELL) of mormyrid electric fish, which
forms a negativ... | biology |
5,215 | K-Winners-Take-All Computation with Neural Oscillators | q-bio.NC | Artificial spike-based computation, inspired by models of computation in the
central nervous system, may present significant performance advantages over
traditional methods for specific types of large scale problems. This paper
describes very simple network architectures for k-winners-take-all and
soft-winner-take-all ... | biology |
5,216 | Graded persisting activity of heterogeneous neuron ensembles subject to white noises | q-bio.NC | Effects of distractions such as noises and parameter heterogeneity have been
studied on the firing activity of ensemble neurons, each of which is described
by the extended Morris-Lecar model showing the graded persisting firings with
the aid of an included ${\rm Ca}^{2+}$-dependent cation current. Although the
sustaine... | biology |
5,217 | Spectra and waiting-time densities in firing resonant and nonresonant neurons | q-bio.NC | The response of a neural cell to an external stimulus can follow one of the
two patterns: Nonresonant neurons monotonously relax to the resting state after
excitation while resonant ones show subthreshold oscillations. We investigate
how do these subthreshold properties of neurons affect their suprathreshold
response. ... | biology |
5,218 | Quantum Physics in Neuroscience and Psychology: A New Theory With Respect to Mind/Brain Interaction | q-bio.NC | The cognitive frame in which most neuropsychological research on the neural
basis of behavior is conducted contains the assumption that brain mechanisms
per se fully suffice to explain all psychologically described phenomena. This
assumption stems from the idea that the brain is made up entirely of material
particles a... | biology |
5,219 | Response variability in balanced cortical networks | q-bio.NC | We study the spike statistics of neurons in a network with dynamically
balanced excitation and inhibition. Our model, intended to represent a generic
cortical column, comprises randomly connected excitatory and inhibitory leaky
integrate-and-fire neurons, driven by excitatory input from an external
population. The high... | biology |
5,220 | Mean field methods for cortical network dynamics | q-bio.NC | We review the use of mean field theory for describing the dynamics of dense,
randomly connected cortical circuits. For a simple network of excitatory and
inhibitory leaky integrate-and-fire neurons, we can show how the firing
irregularity, as measured by the Fano factor, increases with the strength of
the synapses in t... | biology |
5,221 | High conductance states in a mean field cortical network model | q-bio.NC | Measured responses from visual cortical neurons show that spike times tend to
be correlated rather than exactly Poisson distributed. Fano factors vary and
are usually greater than 1 due to the tendency of spikes being clustered into
bursts. We show that this behavior emerges naturally in a balanced cortical
network mod... | biology |
5,222 | Fine Discrimination of Analog Patterns by Nonlinear Dendritic Inhibition | q-bio.NC | Recent experiments revealed that a certain class of inhibitory neurons in the
cerebral cortex make synapses not onto cell bodies but at distal parts of
dendrites of the target neurons, mediating highly nonlinear dendritic
inhibition. We propose a novel form of competitive neural network model that
realizes such dendrit... | biology |
5,223 | Performance of networks of artificial neurons: The role of clustering | q-bio.NC | The performance of the Hopfield neural network model is numerically studied
on various complex networks, such as the Watts-Strogatz network, the
Barab{\'a}si-Albert network, and the neuronal network of the C. elegans.
Through the use of a systematic way of controlling the clustering coefficient,
with the degree of each... | biology |
5,224 | The perception of melodic consonance: an acoustical and neurophysiological explanation based on the overtone series | q-bio.NC | The melodic consonance of a sequence of tones is explained using the overtone
series: the overtones form "flow lines" that link the tones melodically; the
strength of these flow lines determines the melodic consonance. This hypothesis
admits of psychoacoustical and neurophysiological interpretations that fit well
with ... | biology |
5,225 | Mean field theory for a balanced hypercolumn model of orientation selectivity in primary visual cortex | q-bio.NC | We present a complete mean field theory for a balanced state of a simple
model of an orientation hypercolumn. The theory is complemented by a
description of a numerical procedure for solving the mean-field equations
quantitatively. With our treatment, we can determine self-consistently both the
firing rates and the fir... | biology |
5,226 | Pulse-coupled resonate-and-fire models | q-bio.NC | We analyze two pulse-coupled resonate-and-fire neurons. Numerical simulation
reveals that an anti-phase state is an attractor of this model. We can
analytically explain the stability of anti-phase states by means of a return
map of firing times, which we propose in this paper. The resultant stability
condition turns ou... | biology |
5,227 | A toy model of the brain | q-bio.NC | We have designed a toy brain and have written computer code that simulates
it. This toy brain is flexible, modular, has hierarchical learning and
recognition, has short and long term memory, is distributed (i.e. has no
central control), is asynchronous, and includes parallel and series processing.
We have simulated the... | biology |
5,228 | General representation of collective neural dynamics with columnar modularity | q-bio.NC | We exhibit a mathematical framework to represent the neural dynamics at
cortical level. Our description of neural dynamics with columnar and functional
modularity, named fibre bundle representation (FBM) method, is based both on
neuroscience and informatics, whereas they correspond with the conventional
formulas in sta... | biology |
5,229 | Cortical Dynamics and Awareness State: An Interpretation of Observed Interstimulus Interval Dependence in Apparent Motion | q-bio.NC | In a recent paper on Cortical Dynamics, Francis and Grossberg raise the
question how visual forms and motion information are integrated to generate a
coherent percept of moving forms? In their investigation of illusory contours
(which are, like Kanizsa squares, mental constructs rather than stimuli on the
retina) they ... | biology |
5,230 | Predicting spike times of a detailed conductance-based neuron model driven by stochastic spike arrival | q-bio.NC | Reduced models of neuronal activity such as Integrate-and-Fire models allow a
description of neuronal dynamics in simple, intuitive terms and are easy to
simulate numerically. We present a method to fit an Integrate-and-Fire-type
model of neuronal activity, namely a modified version of the Spike Response
Model, to a de... | biology |
5,231 | A subjective distance between stimuli: quantifying the metric structure of representations | q-bio.NC | As subjects perceive the sensory world, different stimuli elicit a number of
neural representations. Here, a subjective distance between stimuli is defined,
measuring the degree of similarity between the underlying representations. As
an example, the subjective distance between different locations in space is
calculate... | biology |
5,232 | How to compute using globally coupled oscillators | q-bio.NC | Synchronization is known to play a vital role within many highly connected
neural systems such as the olfactory systems of fish and insects. In this paper
we show how one can robustly and effectively perform practical computations
using small perturbations to a very simple globally coupled network of coupled
oscillator... | biology |
5,233 | Can Neural Networks Recognize Parts? | q-bio.NC | We have demonstrated neural networks can recognize parts by visual images.
Input signals are gray scale photographs of objects consisting of some parts
and output signals are their shapes. By training neural networks by a few set
of images, without any supervision they become to be able to recognize the
boundary betwee... | biology |
5,234 | Theory of localized synfire chain | q-bio.NC | Neuron is a noisy information processing unit and conventional view is that
information in the cortex is carried on the rate of neurons spike emission.
More recent studies on the activity propagation through the homogeneous network
have demonstrated that signals can be transmitted with millisecond fidelity;
this model ... | biology |
5,235 | Stimulus competition by inhibitory interference | q-bio.NC | When two stimuli are present in the receptive field of a V4 neuron, the
firing rate response is between the weakest and strongest response elicited by
each of the stimuli alone (Reynolds et al, 1999, Journal of Neuroscience
19:1736-1753). When attention is directed towards the stimulus eliciting the
strongest response ... | biology |
5,236 | Effect of Synchronous Incoming Spikes on Activity Pattern in A Network of Spiking Neurons | q-bio.NC | Although recent neurophysiological experiments suggest that synchronous
neural activity is involved in some perceptual and cognitive processes, the
functional role of such coherent neuronal behavior is not well understood. As a
first step in clarifying this role, we investigate how the temporal coherence
of certain neu... | biology |
5,237 | Neurokinematic Modeling of Complex Swimming Patterns of the Larval Zebrafish | q-bio.NC | Larval zebrafish exhibit a variety of complex undulatory swimming patterns.
This repertoire is controlled by the 300 neurons projecting from brain into
spinal cord. Understanding how descending control signals shape the output of
spinal circuits, however, is nontrivial. We have therefore developed a
segmental oscillato... | biology |
5,238 | Activity-dependent brain model explaining EEG spectra | q-bio.NC | Most brain models focus on associative memory or calculation capability,
experimentally inaccessible using physiological methods. Here we present a
model explaining a basic feature of electroencephalograms (EEG). Our model is
based on an electrical network with threshold firing and plasticity of synapses
that reproduce... | biology |
5,239 | Cognitive styles sex the brain, compete neurally, and quantify deficits in autism | q-bio.NC | Introduction: Two key dimensions of the mind are understanding and responding
to another's mental state (empathizing), and analysing lawful behaviour
(systemizing).
Methods: Two questionnaires, the Systemizing Quotient (SQ) and the Empathy
Quotient (EQ), were administered to a normal control group and a group of
indi... | biology |
5,240 | Computational Models of Adult Neurogenesis | q-bio.NC | Experimental results in recent years have shown that adult neurogenesis is a
significant phenomenon in the mammalian brain. Little is known, however, about
the functional role played by the generation and destruction of neurons in the
context of and adult brain. Here we propose two models where new projection
neurons a... | biology |
5,241 | Comment on: "Characterization of subthreshold voltage fluctuations in neuronal membranes" by M. Rudolph and A. Destexhe | q-bio.NC | In two recent papers, Rudolph and Destexhe (Neural Comp. {\bf 15},
2577-2618, 2003; Neural Comp. in press, 2005) studied a leaky integrator
model (i.e. an RC-circuit) driven by correlated (``colored'') Gaussian
conductance noise and Gaussian current noise. In the first paper they derived
an expression for the station... | biology |
5,242 | Autoassociative Memory Retrieval and Spontaneous Activity Bumps in Small-World Networks of Integrate-and-Fire Neurons | q-bio.NC | Qualitatively, some real networks in the brain could be characterized as
'small worlds', in the sense that the structure of their connections is
intermediate between the extremes of an orderly geometric arrangement and of a
geometry-independent random mesh. Small worlds can be defined more precisely in
terms of their m... | biology |
5,243 | Transient Information Flow in a Network of Excitatory and Inhibitory Model Neurons: Role of Noise and Signal Autocorrelation | q-bio.NC | We investigate the performance of sparsely-connected networks of
integrate-and-fire neurons for ultra-short term information processing. We
exploit the fact that the population activity of networks with balanced
excitation and inhibition can switch from an oscillatory firing regime to a
state of asynchronous irregular ... | biology |
5,244 | Signal buffering in random networks of spiking neurons: microscopic vs. macroscopic phenomena | q-bio.NC | In randomly connected networks of pulse-coupled elements a time-dependent
input signal can be buffered over a short time. We studied the signal buffering
properties in simulated networks as a function of the networks state,
characterized by both the Lyapunov exponent of the microscopic dynamics and the
macroscopic acti... | biology |
5,245 | Optimal Spike-Timing Dependent Plasticity for Precise Action Potential Firing | q-bio.NC | In timing-based neural codes, neurons have to emit action potentials at
precise moments in time. We use a supervised learning paradigm to derive a
synaptic update rule that optimizes via gradient ascent the likelihood of
postsynaptic firing at one or several desired firing times. We find that the
optimal strategy of up... | biology |
5,246 | Inhibitory synchrony as a mechanism for attentional gain modulation | q-bio.NC | Recordings from area V4 of monkeys have revealed that when the focus of
attention is on a visual stimulus within the receptive field of a cortical
neuron, two distinct changes can occur: The firing rate of the neuron can
change and there can be an increase in the coherence between spikes and the
local field potential i... | biology |
5,247 | Features and dimensions: Motion estimation in fly vision | q-bio.NC | We characterize the computation of motion in the fly visual system as a
mapping from the high dimensional space of signals in the retinal photodetector
array to the probability of generating an action potential in a motion
sensitive neuron. Our approach to this problem identifies a low dimensional
subspace of signals w... | biology |
5,248 | Noise-enhanced computation in a model of a cortical column | q-bio.NC | Varied sensory systems use noise in order to enhance detection of weak
signals. It has been conjectured in the literature that this effect, known as
stochastic resonance, may take place in central cognitive processes such as the
memory retrieval of arithmetical multiplication. We show in a simplified model
of cortical ... | biology |
5,249 | Wiring cost in the organization of a biological network | q-bio.NC | To find out the role of the wiring cost in the organization of the neural
network of the nematode \textit{Caenorhapditis elegans} (\textit{C. elegans}),
we build the neuronal map of \textit{C. elegans} based on geometrical positions
of neurons and define the cost as inter-neuronal Euclidean distance \textit{d}.
We show... | biology |
5,250 | Dynamics of learning in coupled oscillators tutored with delayed reinforcements | q-bio.NC | In this work we analyze the solutions of a simple system of coupled phase
oscillators in which the connectivity is learned dynamically. The model is
inspired in the process of learning of birdsong by oscine birds. An oscillator
acts as the generator of a basic rhythm, and drives slave oscillators which are
responsible ... | biology |
5,251 | Search for optimal measure for discriminating spike trains with different randomness | q-bio.NC | We wish to discriminate spike sequences based on the degree of irregularity.
For this purpose, we search for a rational expressions of quadratic functions
of consecutive interspike intervals that efficiently measures spiking
irregularity. Under natural assumptions, the functional form of the coefficient
can be paramete... | biology |
5,252 | Postsynaptic mechanisms for the induction of long-term potentiation and long-term depression of synaptic transmission in CA1 pyramidal neurons of the hippocampus | q-bio.NC | The studies described in this dissertation have attempted to address the
cellular mechanisms of information storage by the brain. My work has focused
primarily on the postsynaptic events that occur during and after induction of
long-term potentiation (LTP) and long-term depression (LTD) at the Schaffer
collateral-CA1 s... | biology |
5,253 | Traveling wave solutions of Fitzhugh model with cross-diffusion | q-bio.NC | The Fitzhugh-Nagumo equations have been used as a caricature of the
Hodgkin-Huxley equations of neuron firing to better understand the essential
dynamics of the interaction of the membrane potential and the restoring force
and to capture, qualitatively, the general properties of an excitable membrane.
Even though its s... | biology |
5,254 | Nonlinear aspects of the EEG during sleep in children | q-bio.NC | Electroencephalograph (EEG) analysis enables the neuronal behavior of a
section of the brain to be examined. If the behavior is nonlinear then
nonlinear tools can be used to glean information on brain behavior, and aid in
the diagnosis of sleep abnormalities such as obstructive sleep apnea syndrome
(OSAS). In this pape... | biology |
5,255 | Effects of fast presynaptic noise in attractor neural networks | q-bio.NC | We study both analytically and numerically the effect of presynaptic noise on
the transmission of information in attractor neural networks. The noise occurs
on a very short-time scale compared to that for the neuron dynamics and it
produces short-time synaptic depression. This is inspired in recent
neurobiological find... | biology |
5,256 | Stimulus - response curves of a neuronal model for noisy subthreshold oscillations and related spike generation | q-bio.NC | We investigate the stimulus-dependent tuning properties of a noisy ionic
conductance model for intrinsic subthreshold oscillations in membrane potential
and associated spike generation. On depolarization by an applied current, the
model exhibits subthreshold oscillatory activity with occasional spike
generation when os... | biology |
5,257 | Control of neural chaos by synaptic noise | q-bio.NC | We studied neural automata -or neurobiologically inspired cellular automata-
which exhibits chaotic itinerancy among the different stored patterns or
memories. This is a consequence of activity-dependent synaptic fluctuations,
which continuously destabilize the attractor and induce irregular hopping to
other possible a... | biology |
5,258 | Participatory Ecosystem Management Planning at Tuzla Lake (Turkey) Using Fuzzy Cognitive Mapping | q-bio.NC | A participatory environmental management plan was prepared for Tuzla Lake,
Turkey. Fuzzy cognitive mapping approach was used to obtain stakeholder views
and desires. Cognitive maps were prepared with 44 stakeholders (villagers,
local decisionmakers, government and non-government organization (NGO)
officials). Graph the... | biology |
5,259 | Context-dependent selection of visuomotor maps | q-bio.NC | Behavior results from the integration of ongoing sensory signals and
contextual information in various forms, such as past experience, expectations,
current goals, etc. Thus, the response to a specific stimulus, say the ringing
of a doorbell, varies depending on whether you are at home or in someone else's
house. What ... | biology |
5,260 | Stable Concurrent Synchronization in Dynamic System Networks | q-bio.NC | In a network of dynamical systems, concurrent synchronization is a regime
where multiple groups of fully synchronized elements coexist. In the brain,
concurrent synchronization may occur at several scales, with multiple
``rhythms'' interacting and functional assemblies combining neural oscillators
of many different typ... | biology |
5,261 | Temporal correlation based learning in neuron models | q-bio.NC | We study a learning rule based upon the temporal correlation (weighted by a
learning kernel) between incoming spikes and the internal state of the
postsynaptic neuron, building upon previous studies of spike timing dependent
synaptic plasticity (\cite{KGvHW,KGvH1,vH}). Our learning rule for the synaptic
weight $w_{ij}$... | biology |
5,262 | Attentional modulation of firing rate and synchrony in a model cortical network | q-bio.NC | When attention is directed into the receptive field of a V4 neuron, its
contrast response curve is shifted to lower contrast values (Reynolds et al,
2000, Neuron 26:703). Attention also increases the coherence between neurons
responding to the same stimulus (Fries et al, 2001, Science 291:1560). We
studied how the firi... | biology |
5,263 | Contextual Emergence of Mental States from Neurodynamics | q-bio.NC | The emergence of mental states from neural states by partitioning the neural
phase space is analyzed in terms of symbolic dynamics. Well-defined mental
states provide contexts inducing a criterion of structural stability for the
neurodynamics that can be implemented by particular partitions. This leads to
distinguished... | biology |
5,264 | Waveform sample method of excitable sensory neuron | q-bio.NC | We present a new interpretation for encoding information of the period of
input signals into spike-trains in individual sensory neuronal systems. The
spike-train could be described as the waveform sample of the input signal which
locks sample points to wave crests with randomness. Based on simulations of the
Hodgkin-Hu... | biology |
5,265 | Sleep as the solution to an optimization problem | q-bio.NC | This paper develops a highly simplified model with which to analyze the
phenomenon of sleep. Motivated by Crick's suggestion that sleep is the brain's
way of ``taking out the trash,'' a suggestion that is supported by emerging
evidence, we consider the problem of the filling and emptying of a tank. At any
given time, t... | biology |
5,266 | Glial activation in white matter following ischemia in the neonatal P7 rat brain | q-bio.NC | This study examines cell death and proliferation in the white matter after
neonatal stroke. In post-natal day 7 injured rat, there was a marked reduction
in myelin basic protein (MBP) immunostaining mainly corresponding to numerous
pyknotic immature oligodendrocytes and TUNEL-positive astrocytes in the
ipsilateral exte... | biology |
5,267 | Gradient learning in spiking neural networks by dynamic perturbation of conductances | q-bio.NC | We present a method of estimating the gradient of an objective function with
respect to the synaptic weights of a spiking neural network. The method works
by measuring the fluctuations in the objective function in response to dynamic
perturbation of the membrane conductances of the neurons. It is compatible with
recurr... | biology |
5,268 | Self-Organized Criticality model for Brain Plasticity | q-bio.NC | Networks of living neurons exhibit an avalanche mode of activity,
experimentally found in organotypic cultures. Here we present a model based on
self-organized criticality and taking into account brain plasticity, which is
able to reproduce the spectrum of electroencephalograms (EEG). The model
consists in an electrica... | biology |
5,269 | Concurrent encoding of frequency and amplitude modulation in human auditory cortex: MEG evidence | q-bio.NC | A natural sound can be described by dynamic changes in envelope (amplitude)
and carrier (frequency), corresponding to amplitude modulation (AM) and
frequency modulation (FM) respectively. Although the neural responses to both
AM and FM sounds are extensively studied in both animals and humans, it is
uncertain how they ... | biology |
5,270 | Grandmother cells and the storage capacity of the human brain | q-bio.NC | Quian Quiroga et al. [Nature 435, 1102 (2005)] have recently discovered
neurons that appear to have the characteristics of grandmother (GM) cells. Here
we quantitatively assess the compatibility of their data with the GM-cell
hypothesis. We show that, contrary to the general impression, a GM-cell
representation can be ... | biology |
5,271 | Synchronization in Electrically Coupled Neural Networks | q-bio.NC | In this report, we investigate the synchronization of temporal activity in an
electrically coupled neural network model. The electrical coupling is
established by homotypic static gap-junctions (Connexin 43). Two distinct
network topologies, namely: {\em sparse random network, (SRN)} and {\em fully
connected network, (... | biology |
5,272 | Algorithms for identification and categorization | q-bio.NC | The main features of a family of efficient algorithms for recognition and
classification of complex patterns are briefly reviewed. They are inspired in
the observation that fast synaptic noise is essential for some of the
processing of information in the brain. | biology |
5,273 | Competition between synaptic depression and facilitation in attractor neural networks | q-bio.NC | We study the effect of competition between short-term synaptic depression and
facilitation on the dynamical properties of attractor neural networks, using
Monte Carlo simulation and a mean field analysis. Depending on the balance
between depression, facilitation and the noise, the network displays different
behaviours,... | biology |
5,274 | Chaotic hopping between attractors in neural networks | q-bio.NC | We present a neurobiologically--inspired stochastic cellular automaton whose
state jumps with time between the attractors corresponding to a series of
stored patterns. The jumping varies from regular to chaotic as the model
parameters are modified. The resulting irregular behavior, which mimics the
state of attention i... | biology |
5,275 | Instability of attractors in autoassociative networks with bioinspired fast synaptic noise | q-bio.NC | We studied autoassociative networks in which synapses are noisy on a time
scale much shorter that the one for the neuron dynamics. In our model a
presynaptic noise causes postsynaptic depression as recently observed in
neurobiological systems. This results in a nonequilibrium condition in which
the network sensitivity ... | biology |
5,276 | Combinatorial on/off Model for Olfactory Coding | q-bio.NC | We present a model for olfactory coding based on spatial representation of
glomerular responses. In this model distinct odorants activate specific subsets
of glomeruli, dependent upon the odorant's chemical identity and concentration.
The glomerular response specificities are understood statistically, based on
experime... | biology |
5,277 | Synaptic plasticity of Inhibitory synapse promote synchrony in inhibitory network in presence of heterogeneity and noise | q-bio.NC | Recently spike timing dependent plasticity was observed in inhibitory synapse
in the layer II of entorhinal cortex. The rule provides an interesting zero in
the region of $\Delta t=t_{post}-t_{pre}=0$ and in addition the dynamic range
of the rule lie in gamma frequency band. We propose a robust mechanism based on
this ... | biology |
5,278 | The role of synaptic facilitation in coincidence spike detection | q-bio.NC | Using a realistic model of activity dependent dynamical synapses and a
standard integrate and fire neuron model we study, both analytically and
numerically, the conditions in which a postsynaptic neuron efficiently detects
temporal coincidences of spikes arriving at certain frequency from N different
afferents. We exte... | biology |
5,279 | Chaotic itinerancy, temporal segmentation and spatio-temporal combinatorial codes | q-bio.NC | We study a deterministic dynamics with two time scales in a continuous state
attractor network. To the usual (fast) relaxation dynamics towards point
attractors (``patterns'') we add a slow coupling dynamics that makes the
visited patterns to loose stability leading to an itinerant behavior in the
form of punctuated eq... | biology |
5,280 | Stable Propagation of a Burst Through a One-Dimensional Homogeneous Excitatory Chain Model of Songbird Nucleus HVC | q-bio.NC | We demonstrate numerically that a brief burst consisting of two to six spikes
can propagate in a stable manner through a one-dimensional homogeneous
feedforward chain of non-bursting neurons with excitatory synaptic connections.
Our results are obtained for two kinds of neuronal models, leaky
integrate-and-fire (LIF) n... | biology |
5,281 | Episodic synchronization in dynamically driven neurons | q-bio.NC | We examine the response of type II excitable neurons to trains of synaptic
pulses, as a function of the pulse frequency and amplitude. We show that the
resonant behavior characteristic of type II excitability, already described for
harmonic inputs, is also present for pulsed inputs. With this in mind, we study
the resp... | biology |
5,282 | Theory of Interaction of Memory Patterns in Layered Associative Networks | q-bio.NC | A synfire chain is a network that can generate repeated spike patterns with
millisecond precision. Although synfire chains with only one activity
propagation mode have been intensively analyzed with several neuron models,
those with several stable propagation modes have not been thoroughly
investigated. By using the le... | biology |
5,283 | A new stimulus approach in the search for biological nonlocality | q-bio.NC | Preliminary research in the area of biophysics appears to indicate the
existence of quantum entanglement and nonlocality at the biological level, both
for human subjects and for neurons derived from human neural stem cells. The
lack of clear and replicable findings, especially where human subjects are
concerned, result... | biology |
5,284 | Neural integrator - a sandpile model | q-bio.NC | We investigated a model for the neural integrator based on hysteretic units
connected by positive feedback. Hysteresis is assumed to emerge from the
intrinsic properties of the cells. We consider the recurrent networks
containing either bistable or multistable neurons. We apply our analysis to the
oculomotor velocity-t... | biology |
5,285 | Triangular lattice neurons may implement an advanced numeral system to precisely encode rat position over large ranges | q-bio.NC | We argue by observation of the neural data that neurons in area dMEC of rats,
which fire whenever the rat is on any vertex of a regular triangular lattice
that tiles 2-d space, may be using an advanced numeral system to reversibly
encode rat position. We interpret measured dMEC properties within the framework
of a resi... | biology |
5,286 | Scaling law for the transient behavior of type-II neuron models | q-bio.NC | We study the transient regime of type-II biophysical neuron models and
determine the scaling behavior of relaxation times $\tau$ near but below the
repetitive firing critical current, $\tau \simeq C (I_c-I)^{-\Delta}$. For both
the Hodgkin-Huxley and Morris-Lecar models we find that the critical exponent
is independent... | biology |
5,287 | Perception proximale et distale à l'aide du dispositif de Lenay | q-bio.NC | We present in this article experimental results obtained with the "dispositif
de Lenay" : for a localization task (distal perception) and an orientation
estimation task (proximal perception of the orientation of a cylinder in a
plane). In this last experiment, a "virtual" version of the Lenay device was
used. Results a... | biology |
5,288 | Cerebellar Purkinje Cell Loss in Heterozygous Rora+/-Mice: A Longitudinal Study | q-bio.NC | The staggerer (sg/sg) mutation is a spontaneous deletion in the Rora gene
that prevents the translation of the ligand-binding domain (LBD), leading to
the loss of ROR\alpha activity. The homozygous Rorasg/sg mutant mouse, whose
most obvious phenotype is ataxia associated with cerebellar degeneration, also
displays a va... | biology |
5,289 | Pushing it to the Limit: Adaptation With Dynamically Switching Gain Control | q-bio.NC | With this paper we propose a model to simulate the functional aspects of
light adaptation in retinal photoreceptors. Our model, however, does not link
specific stages to the detailed molecular processes which are thought to
mediate adaptation in real photoreceptors. We rather model the photoreceptor as
a self-adjusting... | biology |
5,290 | Activity-dependent self-wiring is a basis of structural plastisity in neural networks | q-bio.NC | Dynamical wiring and rewiring in neural networks are carried out by
activity-dependent growth and retraction of axons and dendrites, guided by
gudance molecules, released by target cells. Experience-dependent structural
changes in cortical microcurcuts lead to changes in activity, i.e. to changes
in information encoded... | biology |
5,291 | Structural network heterogeneities and network dynamics: a possible dynamical mechanism for hippocampal memory reactivation | q-bio.NC | The hippocampus has the capacity for reactivating recently acquired memories
[1-3] and it is hypothesized that one of the functions of sleep reactivation is
the facilitation of consolidation of novel memory traces [4-11]. The dynamic
and network processes underlying such a reactivation remain, however, unknown.
We show... | biology |
5,292 | Unbalanced synaptic inhibition can create intensity-tuned auditory cortex neurons | q-bio.NC | Intensity-tuned auditory cortex neurons may be formed by intensity-tuned
synaptic excitation. Synaptic inhibition has also been shown to enhance, and
possibly even create intensity-tuned neurons. Here we show, using in vivo whole
cell recordings in pentobarbital-anesthetized rats, that some intensity-tuned
neurons are ... | biology |
5,293 | Learning with incomplete information - and the mathematical structure behind it | q-bio.NC | Learning and the ability to learn are important factors in development and
evolutionary processes [1]. Depending on the level, the complexity of learning
can strongly vary. While associative learning can explain simple learning
behaviour [1,2] much more sophisticated strategies seem to be involved in
complex learning t... | biology |
5,294 | Searching for memories, Sudoku, implicit check-bits, and the iterative use of not-always-correct rapid neural computation | q-bio.NC | The algorithms that simple feedback neural circuits representing a brain area
can rapidly carry out are often adequate to solve only easy problems, and for
more difficult problems can return incorrect answers. A new
excitatory-inhibitory circuit model of associative memory displays the common
human problem of failing t... | biology |
5,295 | Calculating event-triggered average synaptic conductances from the membrane potential | q-bio.NC | The optimal patterns of synaptic conductances for spike generation in central
neurons is a subject of considerable interest. Ideally, such conductance time
courses should be extracted from membrane potential (Vm) activity, but this is
difficult because the nonlinear contribution of conductances to the Vm renders
their ... | biology |
5,296 | The Hilbert transform of horizontal gaze position during natural image classification by saccades | q-bio.NC | Eye movements are a behavioral response that can be involved in tasks as
complicated as natural image classification. This report confirms that pro- and
anti-saccades can be used by a volunteer to designate target (animal) or
non-target images that were centered 16 degrees off the fixation point. With
more than 86% cor... | biology |
5,297 | Toward an adequate mathematical model of mental space: conscious/unconscious dynamics on $m$-adic trees | q-bio.NC | We try to perform geometrization of cognitive science and psychology by
representing information states of cognitive systems by points of {\it mental
space} given by a hierarchic $m$-adic tree. Associations are represented by
balls and ideas by collections of balls. We consider dynamics of ideas based on
lifting of dyn... | biology |
5,298 | Correlation entropy of synaptic input-output dynamics | q-bio.NC | The responses of synapses in the neocortex show highly stochastic and
nonlinear behavior. The microscopic dynamics underlying this behavior, and its
computational consequences during natural patterns of synaptic input, are not
explained by conventional macroscopic models of deterministic ensemble mean
dynamics. Here, w... | biology |
5,299 | Brain, Music and non-Poisson Renewal Processes | q-bio.NC | In this paper we show that both music composition and brain function, as
revealed by the Electroencephalogram (EEG) analysis, are renewal non-Poisson
processes living in the non-ergodic dominion. To reach this important
conclusion we process the data with the minimum spanning tree method, so as to
detect significant ev... | biology |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.