scholarly journals Baseline Shift in Neuronal Oscillations and Its Implications for the Interpretation of Evoked Activity Obtained with EEG/MEG

2021 ◽  
Author(s):  
Alina A. Studenova ◽  
Arno Villringer ◽  
Vadim V. Nikulin
Keyword(s):  
Amplitude Modulation ◽  
Computational Modelling ◽  
Strong Support ◽  
Biophysical Model ◽  
Evoked Responses ◽  
Neuronal Oscillations ◽  
Data Set ◽  
Baseline Shift ◽  
Eeg Data ◽  
Evoked Activity

AbstractOscillations and evoked responses are two types of neuronal activity recorded non-invasively with EEG/MEG. Although typically studied separately, they might in fact represent the same process. One possibility to unite them is to demonstrate that neuronal oscillations have non-zero mean which would indicate that stimulus-relating amplitude modulation of neuronal oscillations should lead to the generation of evoked responses. We validated this mechanism using computational modelling and analysis of a large EEG data set. With a biophysical model generating alpha rhythm, we indeed demonstrated that the oscillatory mean is nonzero for a large range of model-parameter values. In EEG data we detected non-zero mean alpha oscillations in about 96% of the participants. Furthermore, using neuronal-ensemble modelling, we provided an explanation for the often observed discrepancies between amplitude modulation and baseline shifts. Overall, our results provide strong support for the unification of neuronal oscillations and evoked responses.

Machine Learning Verdict of EEG Signals in Brain Computer Interface

2018 ◽  
pp. 429-441
Author(s):  
M. Jeyanthi ◽  
C. Velayutham
Keyword(s):  
Nearest Neighbor ◽  
Technology Development ◽  
Vital Role ◽  
Svm Classifier ◽  
K Nearest Neighbor ◽  
Data Mining Technique ◽  
Data Set ◽  
Eeg Data ◽  
Irrelevant Attributes

In Science and Technology Development BCI plays a vital role in the field of Research. Classification is a data mining technique used to predict group membership for data instances. Analyses of BCI data are challenging because feature extraction and classification of these data are more difficult as compared with those applied to raw data. In this paper, We extracted features using statistical Haralick features from the raw EEG data . Then the features are Normalized, Binning is used to improve the accuracy of the predictive models by reducing noise and eliminate some irrelevant attributes and then the classification is performed using different classification techniques such as Naïve Bayes, k-nearest neighbor classifier, SVM classifier using BCI dataset. Finally we propose the SVM classification algorithm for the BCI data set.

scholarly journals Random Sequencing of Paramecium Somatic DNA

2002 ◽  
Vol 1 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Linda Sperling ◽  
Philippe Dessen ◽  
Marek Zagulski ◽  
Ron E. Pearlman ◽  
Andrzey Migdalski ◽  
...  
Keyword(s):  
Germ Line ◽  
Gene Discovery ◽  
Strong Support ◽  
Distance Matrix ◽  
Sexual Cycle ◽  
Phylogenetic Position ◽  
Paramecium Tetraurelia ◽  
Data Set ◽  
Somatic Genome ◽  
Random Survey

ABSTRACT We report a random survey of 1 to 2% of the somatic genome of the free-living ciliate Paramecium tetraurelia by single-run sequencing of the ends of plasmid inserts. As in all ciliates, the germ line genome of Paramecium (100 to 200 Mb) is reproducibly rearranged at each sexual cycle to produce a somatic genome of expressed or potentially expressed genes, stripped of repeated sequences, transposons, and AT-rich unique sequence elements limited to the germ line. We found the somatic genome to be compact (>68% coding, estimated from the sequence of several complete library inserts) and to feature uniformly small introns (18 to 35 nucleotides). This facilitated gene discovery: 722 open reading frames (ORFs) were identified by similarity with known proteins, and 119 novel ORFs were tentatively identified by internal comparison of the data set. We determined the phylogenetic position of Paramecium with respect to eukaryotes whose genomes have been sequenced by the distance matrix neighbor-joining method by using random combined protein data from the project. The unrooted tree obtained is very robust and in excellent agreement with accepted topology, providing strong support for the quality and consistency of the data set. Our study demonstrates that a random survey of the somatic genome of Paramecium is a good strategy for gene discovery in this organism.

scholarly journals Phylogenetic Position of the New World Quail (Odontophoridae): Eight Nuclear Loci and Three Mitochondrial Regions Contradict Morphology and the Sibley-Ahlquist Tapestry

The Auk ◽  
2007 ◽  
Vol 124 (1) ◽  
pp. 71-84 ◽  
Author(s):  
W. Andrew Cox ◽  
Rebecca T. Kimball ◽  
Edward L. Braun
Keyword(s):  
New World ◽  
Sequence Data ◽  
Evolutionary Relationship ◽  
Strong Support ◽  
Nuclear Data ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Data Set ◽  
Mitochondrial Data ◽  
Nuclear Loci

Abstract The evolutionary relationship between the New World quail (Odontophoridae) and other groups of Galliformes has been an area of debate. In particular, the relationship between the New World quail and guineafowl (Numidinae) has been difficult to resolve. We analyzed >8 kb of DNA sequence data from 16 taxa that represent all major lineages of Galliformes to resolve the phylogenetic position of New World quail. A combined data set of eight nuclear loci and three mitochondrial regions analyzed with maximum parsimony, maximum likelihood, and Bayesian methods provide congruent and strong support for New World quail being basal members of a phasianid clade that excludes guineafowl. By contrast, the three mitochondrial regions exhibit modest incongruence with each other. This is reflected in the combined mitochondrial analyses that weakly support the Sibley-Ahlquist topology that placed the New World quail basal in relation to guineafowl and led to the placement of New World quail in its own family, sister to the Phasianidae. However, simulation-based topology tests using the mitochondrial data were unable to reject the topology suggested by our combined (mitochondrial and nuclear) data set. By contrast, similar tests using our most likely topology and our combined nuclear and mitochondrial data allow us to strongly reject the Sibley-Ahlquist topology and a topology based on morphological data that unites Old and New World quail. Posición Filogenética de las Codornices del Nuevo Mundo (Odontophoridae): Ocho Loci Nucleares y Tres Regiones Mitocondriales Contradicen la Morfología y la Filogenia de Sibley y Ahlquist

scholarly journals On the correspondence of electrical and optical physiology in in vivo population-scale two-photon calcium imaging

2019 ◽  
Author(s):  
Peter Ledochowitsch ◽  
Lawrence Huang ◽  
Ulf Knoblich ◽  
Michael Oliver ◽  
Jerome Lecoq ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Biophysical Model ◽  
Data Set ◽  
Two Photon ◽  
Simultaneous Imaging ◽  
Fluorescence Measurements ◽  
Large Populations ◽  
Intractable Problem ◽  
Mouse Lines

AbstractMultiphoton calcium imaging is commonly used to monitor the spiking of large populations of neurons. Recovering action potentials from fluorescence necessitates calibration experiments, often with simultaneous imaging and cell-attached recording. Here we performed calibration for imaging conditions matching those of the Allen Brain Observatory. We developed a novel crowd-sourced, algorithmic approach to quality control. Our final data set was 50 recordings from 35 neurons in 3 mouse lines. Our calibration indicated that 3 or more spikes were required to produce consistent changes in fluorescence. Moreover, neither a simple linear model nor a more complex biophysical model accurately predicted fluorescence for small numbers of spikes (1-3). We observed increases in fluorescence corresponding to prolonged depolarizations, particularly in Emx1-IRES-Cre mouse line crosses. Our results indicate that deriving spike times from fluorescence measurements may be an intractable problem in some mouse lines.

scholarly journals Binaural summation of amplitude modulation involves weak interaural suppression

2018 ◽  
Author(s):  
D.H. Baker ◽  
G. Vilidaite ◽  
E. McClarnon ◽  
E. Valkova ◽  
A. Bruno ◽  
...  
Keyword(s):  
Amplitude Modulation ◽  
Modulation Depth ◽  
Visual Signal ◽  
Data Sets ◽  
Single Object ◽  
Ecological Constraints ◽  
Binaural Summation ◽  
Eeg Data ◽  
Signal Combination ◽  
The Brain

AbstractThe brain combines sounds from the two ears, but what is the algorithm used to achieve this summation of signals? Here we combine psychophysical amplitude modulation discrimination and steady-state electroencephalography (EEG) data to investigate the architecture of binaural combination for amplitude-modulated tones. Discrimination thresholds followed a ‘dipper’ shaped function of pedestal modulation depth, and were consistently lower for binaural than monaural presentation of modulated tones. The EEG responses were greater for binaural than monaural presentation of modulated tones, and when a masker was presented to one ear, it produced only weak suppression of the response to a signal presented to the other ear. Both data sets were well-fit by a computational model originally derived for visual signal combination, but with suppression between the two channels (ears) being much weaker than in binocular vision. We suggest that the distinct ecological constraints on vision and hearing can explain this difference, if it is assumed that the brain avoids over-representing sensory signals originating from a single object. These findings position our understanding of binaural summation in a broader context of work on sensory signal combination in the brain, and delineate the similarities and differences between vision and hearing.

scholarly journals Loophole-Free Bell Tests and the Falsification of Local Realism

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Patrick Thomas Fraser ◽  
Barry C Sanders
Keyword(s):  
Quantum Mechanics ◽  
Theoretical Basis ◽  
Strong Support ◽  
Local Realism ◽  
Data Set ◽  
Strict Locality ◽  
Locality Conditions

Quantum mechanics is strictly incompatible with local realism. It has been shown by Bell and others that it is possible, in principle, to experimentally differentiate between local realism and quantum mechanics. Numerous experiments have attempted to falsify local realism; however, they have consistently failed to close the detection loophole under strict locality conditions, thereby allowing local realistic explanations for their observations. In 2015, three experiments took place that tested local realism without the impediments of these significant loopholes. Between these three experiments, a substantial data set was collected. All of the collected data show a strong violation of local realism and strong support for quantum mechanics. This article reviews the theoretical basis of Bell tests and the affiliated loopholes, as well as the methods employed by these recent experiments and the implications of the results they observed. La mécanique quantique est strictement incompatible avec le réalisme local. Bell et d’autres scientifiques ont montré qu’il est possible, en théorie, de trouver la différence entre le réalisme local et la mécanique quantique expérimentalement. De nombreuses expériences ont tenté de falsifier le réalisme local; cependant, elles ont toujours échoué à combler la faille de détection dans des conditions de localité strictes, permettant ainsi des explications réalistes locales pour leurs observations. En 2015, trois expériences ont testé le réalisme local sans les entraves de ces failles importantes. Entre ces trois expériences, des données substantielles ont été recueillies. Toutes les données recueillies ont montré une forte déviation du réalisme local et un appui solid pour la mécanique quantique. Cet article examine les bases théoriques des tests de Bell et les failles af liées, ainsi que les méthodes employées par ces expériences récentes et les implications de leurs résultats. 

Improving firm performance through inter-organizational collaborative innovations

2018 ◽  
Vol 56 (6) ◽  
pp. 1167-1182 ◽  
Author(s):  
Miguel Hernandez-Espallardo ◽  
Fabian Osorio-Tinoco ◽  
Augusto Rodriguez-Orejuela
Keyword(s):  
Firm Performance ◽  
Open Innovation ◽  
Structural Equation ◽  
Strong Support ◽  
Equation Model ◽  
Data Set ◽  
Content Type ◽  
Mediating Role ◽  
Innovation Culture ◽  
Collaborative Innovation

Purpose The purpose of this paper is to add to the existing knowledge about how firm performance is influenced by their involvement in collaborative innovation. The contextual resource-based dimensions improve the participating firm’s performance through its impact on the job-related attitudes of the firm’s personnel. Design/methodology/approach Hypotheses were tested using structural equation model to analyze a set of data collected through surveys among a sample of Colombian manufacturers. Findings This study provides empirical evidence that contributes to the scarce research in the open innovation arena about how human resources influence performance in the inter-organizational collaborative innovations. In particular, it offers strong support for the key mediating role of the employees’ job-related attitudes in the relationship between complementary capabilities and innovation culture as value-creating conditions, and the participating firm’s ultimate sales and financial performance. Research limitations/implications The results may be affected by the context of the data set. Further studies considering the influence of specific contextual variables, such as the type of innovation, the national culture or the type of partner, could yield richer insights that would help validate the results of this study. Practical implications This study provides useful information for managers. As well as creating the required conditions to add value in the collaborative innovation, they should work to guarantee the better job-related outcomes for the employees involved in collaborative innovation projects. Originality/value This research contributes to the open innovation literature. It posits the employee’s attitudes toward collaborative innovations as a factor of the utmost importance in determining how the external collaboration affects internal performance.

Ensuring Peace: Foreign-Imposed Regime Change and Postwar Peace Duration, 1914–2001

2008 ◽  
Vol 62 (4) ◽  
pp. 717-736 ◽  
Author(s):  
Nigel Lo ◽  
Barry Hashimoto ◽  
Dan Reiter
Keyword(s):  
Regime Change ◽  
Strong Support ◽  
Balance Of Power ◽  
Third Party ◽  
Regime Type ◽  
Data Set ◽  
Factors Affecting ◽  
Third Party Intervention ◽  
Central Hypothesis ◽  
Peace Duration

This research note develops a new explanation of postwar peace duration: periods of peace following wars last longer when the war ends in foreign-imposed regime change. This study tests this hypothesis on a new data set (an expansion of Fortna's (2004) data) of all periods of peace following interstate war cease-fires, over the period 1914–2001. It also tests for other possible factors affecting postwar peace duration, including international institutions, the revelation of information during war, third-party intervention during war, postwar changes in the balance of power, regime type, past conflict history, and others. The article finds strong support for the central hypothesis that peace lasts longer following wars that end in foreign-imposed regime change. This pacifying effect diminishes over time when a puppet is imposed, but not when a democracy is imposed. There are other results, including that the strength of a cease-fire agreement has almost no impact on peace duration.

scholarly journals The acquisition of plural marking in English and German revisited: schemata versus rules

1998 ◽  
Vol 25 (2) ◽  
pp. 293-319 ◽  
Author(s):  
KLAUS-MICHAEL KÖPCKE
Keyword(s):  
Strong Support ◽  
Schema Theory ◽  
Strength Analysis ◽  
Inflectional Morphology ◽  
Data Set ◽  
Schema Learning ◽  
German Speaking ◽  
German Children ◽  
Schema Model ◽  
Complex Words

This article contributes to a debate in the linguistic and psychological literature that centres around the representation of morphologically complex words in the grammar and in the lexicon. The issue is whether inflectional morphology is rule-based (i.e. symbolically represented), or whether the assumption of pattern association is more adequate to account for the facts. On the basis of the analysis of acquisitional data the article strongly argues for the latter alternative. In a classic experiment that helped shape the development of acquisition theory Berko (1958) reported substantial support for item-and-process rules in the acquisition of plural morphology in English. A large part of her results were zero responses (repetition of the stimulus). A reinterpretation of these zero responses in light of schema theory and the cue strength hypothesis shows a striking departure from randomness. Berko's subjects tended to repeat stimuli just to the extent that these already resembled a plural schema. A reinterpretation of data reported in Innes (1974) achieved compatible results. This data set is far more extensive than Berko's and is used in the present study to put the schema model to a more stringent test. A reinterpretation of a parallel experiment with German children, using the cue strength analysis of the more complex plural morphology of German yielded parallel results. Finally, natural acquisitional data obtained from seven German speaking children aged between 2;1 and 2;9 are analysed. Again, strong support is found for the schema model. It is suggested that a schema-learning mechanism may underlie the acquisition of morphology, even when the end product of the learning process involves item-and-process rules, as in the case of English plural formation. In a schema-learning model, the child builds schematic representations for possible singular and plural lexical items as whole gestalts, and attempts to map concrete forms onto these schemata in deciding whether the forms have singular or plural value.

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