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Cyclic coding algorithms under MorphoSys reconfigurable computing system

ADVANCES IN ENGINEERING SOFTWARE 2003年第2期34卷 61-72页

作者： Diab, H Damaj, I S Bank Univ Fac Engn Sci & Technol London SE1 0AA England Amer Univ Beirut Fac Engn & Architecture Dept ECE Beirut Lebanon

This paper introduces reconfigurable computing (RC) and specifically chooses one of the prototypes in this field, MorphoSys (M1) [1-5]. The paper addresses the results obtained when using RC in mapping algorithms pertaining to digital coding in relation to previous research [6-10]. The chosen algorithms relate to cyclic coding techniques, namely the CCITT CRC-16 and the CRC-16. A performance analysis study of the M1 RC system is also presented to evaluate the efficiency of the algorithm execution on the M1 system. For comparison purposes, three other systems were used to map the same algorithms showing the advantages and disadvantages of each compared with the M1 system. The algorithms were run on the 8 X 8 RC (reconfigurable) array of the M1 (MorphoSys) system;numerical examples were simulated to validate our results, using the MorphoSys mULATE program, which simulates MorphoSys operations. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： reconfigurable computing MorphoSys information coding cyclic codes algorithms mapping

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Novel systematic mathematical computation based on the spiking frequency gate (SFG): Innovative organization of spiking computer

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information SCIENCES 2019年 474卷 221-235页

作者： Nazari, Soheila Faez, Karim Amirkabir Univ Technol Dept Elect Engn Tehran Iran Kermanshah Univ Med Sci Nano Drug Delivery Res Ctr Kermanshah Iran

The idea that the brain is composed of logical gates similar to IP cores of today's computers were provided by McCulloch and Pitts in 1943. In this paper, six structures for the interaction of dynamic neurons have been proposed to create neural circuits with spike coding that operate similarly to Boolean gates. It was concluded that the network of the dynamic model of spiking neurons and synapses called spiking frequency gates (SFG) can emulate the operations of digital gates AND, OR, NOT, NOR, XOR, and NAND. Also, an attempt was made to construct complex spiking circuits like full-adder, multiplexer, and arithinetic-logic-unit using cascade connections of SFGs. Extending simple designs to more complex spiking circuits can continue in order to access sophisticated computing tools based on SFGs. SFGs are not limited to zero and one and respond to the continuous range of spike train frequencies. Therefore, the information coding of SFGs is more powerful than Boolean gates. This paper illustrates a novel Boolean computation platform in a neural-like manner, which can provide a potential and clear horizon for designing neural circuits with complex applications. We hope that our results will lead to a deeper comprehension of the brain's functionalities and the development of new systematic methods based on the proposed spiking approach of Boolean logic gates. (C) 2018 Elsevier Inc. All rights reserved.

关键词： Spiking frequency gates Boolean computation Spiking circuit information coding Pattern recognition

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Identification of the phase code in an EEG during gripping-force tasks: A possible alternative approach to the development of the brain-computer interfaces

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ARTIFICIAL INTELLIGENCE IN MEDICINE 2008年第1期44卷 41-49页

作者： Logar, Vito Skrjanc, Igor Belic, Ales Brezan, Simon Koritnik, Blaz Zidar, Janez Univ Ljubljana Fac Elect Engn LMSV & LAIP SI-1000 Ljubljana Slovenia Univ Med Ctr Ljubljana Inst Clin Neurophysiol SI-1525 Ljubljana Slovenia

Background: The subject of brain-computer interfaces (BCIs) represents a vast and still mainly undiscovered land, but perhaps the most interesting part of BCIs is trying to understand the information exchange and coding in the brain itself. According to some recent reports, the phase characteristics of the signals play an important rote in the information transfer and coding. The mechanism of phase shifts, regarding the information processing, is also known as the phase coding of information. Objective: The authors would like to show that etectroencephalographic (EEG) signals, measured during the performance of different gripping-force control tasks, carry enough information for the successful prediction of the gripping force, as applied by the subjects, when using a methodology based on the phase demodulation of EEG data. Since the presented methodology is non-invasive it could be used as an alternative approach for the development of BCIs. Materials and methods: In order to predict the gripping force from the EEG signals we used a methodology that uses subsequent signal processing methods: simplistic filtering methods, for extracting the appropriate brain rhythm;principal component analysis, for achieving the linear independence and detecting the source of the signal;and the phase-demodulation method, for extracting the phase-coded information about the gripping force. A fuzzy inference system is then used to predict the gripping force from the processed EEG data. Results: The proposed methodology has clearly demonstrated that EEG signals carry enough information for a successful prediction of the subject's performance. Moreover, a cross-validation showed that information about the gripping force is encoded in a very similar way between the subjects tested. As for the development of BCIs, considering the computational time to pre-process the data and train the fuzzy model, a real-time online analysis would be possible if the real-time non-causal limitations of the

关键词： Brain-computer interface Electroencephalography Fuzzy logic Gripping force information coding Phase demodulation Principal component analysis

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Self-organization in the olfactory system: one shot odor recognition in insects

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BIOLOGICAL CYBERNETICS 2005年第6期93卷 436-446页

作者： Nowotny, T Huerta, R Abarbanel, HDI Rabinovich, MI Univ Calif San Diego Inst Nonlinear Sci La Jolla CA 92093 USA Univ Calif San Diego Scripps Inst Oceanog Dept Phys La Jolla CA 93093 USA Univ Calif San Diego Scripps Inst Oceanog Marine Phys Lab La Jolla CA 93093 USA

We show in a model of spiking neurons that synaptic plasticity in the mushroom bodies in combination with the general fan-in, fan-out properties of the early processing layers of the olfactory system might be sufficient to account for its efficient recognition of odors. For a large variety of initial conditions the model system consistently finds a working solution without any fine-tuning, and is, therefore, inherently robust. We demonstrate that gain control through the known feedforward inhibition of lateral horn interneurons increases the capacity of the system but is not essential for its general function. We also predict an upper limit for the number of odor classes Drosophila can discriminate based on the number and connectivity of its olfactory neurons.

关键词： olfaction pattern recognition synaptic convergence information coding fan-in fan-out

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information rate and spike-timing precision of proprioceptive Afferents

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JOURNAL OF NEUROPHYSIOLOGY 2007年第3期98卷 1706-1717页

作者： DiCaprio, Ralph A. Billimoria, Cyrus P. Ludwar, Bjoern Ch. Ohio Univ Dept Biol Sci Athens OH 45701 USA

Proprioception in the first two joints of crustacean limbs is mediated by chordotonal organs that utilize spike-mediated information coding and transmission and by non-spiking proprioceptive afferents that use graded transmission at information rates in excess of 2,500 bits/s. Chordotonal organs operate in parallel with the graded receptors, but the information rates of the spiking chordotonal afferents have not been previously determined. Lower-bound estimates of chordotonal afferent information rates were calculated using stimulus reconstruction, which assumes linear encoding of the stimulus. The information rate was also directly estimated from the spike train entropy, which makes no a priori assumptions with respect to the coding scheme used by the system. Lower-bound information rate estimates ranged from 43 to 69 bits/s, whereas the direct estimates ranged from 24 to 278 bits/ s. Comparison of both estimates derived from the same data set indicates that a linear decoder could recover an average of 59% of the information from the spike train. Afferent spike timing was found to be extremely precise, with spikes evoked with an average timing jitter of 0.55 ms. information rate was correlated with the mean jitter and the noise entropy of the spike train could be predicted from the mean firing rate and mean jitter. Direct stimulation of single afferents by current injection into the soma revealed that the average timing jitter was < 0.1 ms, indicating that intrinsic membrane properties, spike generation, and mechano-transduction mechanisms are the major sources of timing jitter in this system.

关键词： information Lower millisecond Entropy 熵 entropy timing precision information rates Membrane properties Dataset information coding MILLISECOND timing jitter

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Functional modules of the brain

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JOURNAL OF THEORETICAL BIOLOGY 2002年第1期215卷 109-119页

作者： Philipson, L Lund Univ Dept Informat Technol SE-22100 Lund Sweden

Building on the view of massive modularity, a number of generalized assumptions lead to an entirely new concept of functional brain modules. In contrast to the nerve centers usually considered to be active in the brain, these modules, called symbions, are non-localized, non-hierarchical. and based on subcellular molecular mechanisms rather than on neurons. They act according to local rules that may be fundamentally nonlinear, potentially leading to strong interdependencies between parallel inputs, and they interact by information, not by force. The existence of inner states, feedback loops. internal models, and information encoding provide the basis for a higher complexity than is usually assumed in neuroscience. A map of the symbion world, showing functional rather than physical localization, can be used to illustrate symbion interaction patterns. Perceptual constancy, sensory illusions, visual cognition, and eye-hand coordination are used as examples of what can be explained by using the new theory. (C) 2002 Elsevier Science Ltd.

关键词： Brain Functional agreement encoding eye-hand coordination 脑 Cerebrum function block Perceptual Constancy Hand eye coordination coding information coding FUNCTIONALS

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Males use time whereas females prefer harmony: individual call recognition in the dimorphic blue-footed booby

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ANIMAL BEHAVIOUR 2012年第2期84卷 413-420页

作者： Dentressangle, Fabrice Aubin, Thierry Mathevon, Nicolas Univ St Etienne ENES CNPS CNRS UMR 8195 F-42023 St Etienne 2 France Ctr Neurosci Paris Sud CNRS UMR 8195 Paris France Univ Nacl Autonoma Mexico Lab Conducta Anim Inst Ecol Mexico City 04510 DF Mexico Univ Paris 11 CNPS Equipe Communicat Acoust CNRS UMR 8195 Orsay France

In breeding birds, acoustic signalling is often an important cue for reunion between sexual partners. However, in spite of its potential interest, mate recognition has rarely been examined by comparing the two sexes. We studied the blue-footed booby, Sula nebouxii, a socially monogamous seabird, with a dramatic call sexual dimorphism suggesting two different strategies for identity coding: the female call is an amplitude-modulated sound with a harmonic series slowly modulated in frequency, while the male call is a noisy whistle strongly modulated in frequency. To compare acoustic strategies between the sexes, we (1) recorded calls of both males and females, (2) searched for an individual signature and characterized it, and (3) tested, using a playback experiment, whether the calls of males and females were equally efficient for mate recognition. Results showed that an individual signature was present in the calls of both sexes. However, the acoustic parameters involved differed: female individual identification was principally achieved by a spectral analysis of the call whereas males' identity relied mostly on temporal cues. More than 70% of both females and males tested in playback experiments successfully recognized their mate. This suggests that the coding strategies are equally efficient in terms of individual recognition between mates. From a broader point of view, our results underline the importance of assessing both males and females within the same investigative framework. (C) 2012 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

关键词： acoustic communication blue-footed booby information coding pair bond reproduction seabird sex difference social monogamy Sula nebouxii

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Effects of Dopamine Depletion on Network Entropy in the External Globus Pallidus

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JOURNAL OF NEUROPHYSIOLOGY 2009年第2期102卷 1092-1102页

作者： Cruz, Ana V. Mallet, Nicolas Magill, Peter J. Brown, Peter Averbeck, Bruno B. UCL Inst Neurol Sobell Dept Motor Neurosci & Movement Disorders London WC1N 3BG England Inst Gulbenkian Ciencias Oeiras Portugal Univ Oxford Med Res Council Anat Neuropharmacol Unit Oxford England

Cruz AV, Mallet N, Magill PJ, Brown P, Averbeck BB. Effects of dopamine depletion on network entropy in the external globus pallidus. J Neurophysiol 102: 1092-1102, 2009. First published June 17, 2009;doi: 10.1152/jn.00344.2009. Dopamine depletion in cortical-basal ganglia circuits in Parkinson's disease (PD) grossly disturbs movement and cognition. Classic models relate Parkinsonian dysfunction to changes in firing rates of basal ganglia neurons. However, disturbances in other dynamics of neural activity are also common. Taking both inappropriate firing rates and other dynamics into account and determining how changes in the properties of these neural circuits that occur during PD impact on information coding are thus imperative. Here, we examined in vivo network dynamics in the external globus pallidus (GPe) of rats before and after chronic dopamine depletion. Dopamine depletion led to decreases in the firing rates of GPe neurons and increases in synchronized network oscillations in the beta frequency (13-30 Hz) band. Using logistic regression models, we determined the combined and separate impacts of these factors on network entropy, a measure of the upper bound of information coding capacity. Importantly, changes in these features in dopamine-depleted rats led to a significant decrease in GPe network entropy. Changes in firing rates had the largest impact on entropy, with changes in synchrony also decreasing entropy at the network level. Changes in autocorrelations tended to offset these effects because autocorrelations decreased entropy more in the control animals. Thus it is possible that reduced information coding capacity within basal ganglia networks may contribute to the behavioral deficits accompanying PD.

关键词： entropy external globus pallidus Autocorrelation Network Basal Ganglia information coding network level Dopamine FIRING RATE

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Cognition as a Window into Neuronal Population Space

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ANNUAL REVIEW OF NEUROSCIENCE, VOL 41 2018年第1期41卷 77-+页

作者： Ruff, Douglas A. Ni, Amy M. Cohen, Marlene R. Univ Pittsburgh Dept Neurosci Pittsburgh PA 15213 USA Univ Pittsburgh Ctr Neural Basis Cognit Pittsburgh PA 15213 USA

Understanding how cognitive processes affect the responses of sensory neurons may clarify the relationship between neuronal population activity and behavior. However, tools for analyzing neuronal activity have not kept up with technological advances in recording from large neuronal populations. Here, we describe prevalent hypotheses of how cognitive processes affect sensory neurons, driven largely by a model based on the activity of single neurons or pools of neurons as the units of computation. We then use simple simulations to expand this model to a new conceptual framework that focuses on subspaces of population activity as the relevant units of computation, uses comparisons between brain areas or to behavior to guide analyses of these subspaces, and suggests that population activity is optimized to decode the large variety of stimuli and tasks that animals encounter in natural behavior. This framework provides new ways of understanding the ever-growing quantity of recorded population activity data.

关键词： information coding visual cortex cognition attention spike count correlations noise correlations

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Efficient coding in heterogeneous neuronal populations

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2008年第42期105卷 16344-16349页

作者： Chelaru, Mircea I. Dragoi, Valentin Univ Texas Houston Sch Med Dept Neurobiol & Anat Houston TX 77030 USA

A ubiquitous feature of neuronal responses within a cortical area is their high degree of inhomogeneity. Even cells within the same functional column are known to have highly heterogeneous response properties when the same stimulus is presented. Whether the wide diversity of neuronal responses is an epiphenomenon or plays a role for cortical function is unknown. Here, we examined the relationship between the heterogeneity of neuronal responses and population coding. Contrary to our expectation, we found that the high variability of intrinsic response properties of individual cells changes the structure of neuronal correlations to improve the information encoded in the population activity. Thus, the heterogeneity of neuronal responses is in fact beneficial for sensory coding when stimuli are decoded from the population response.

关键词： computational modeling information coding sensory cortex visual cortex neuronal populations

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