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Sample records for synchronized auditory signals

  1. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2014-03-01

    Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  2. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2014-01-01

    In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  3. Abnormal auditory synchronization in stuttering: A magnetoencephalographic study.

    Science.gov (United States)

    Kikuchi, Yoshikazu; Okamoto, Tsuyoshi; Ogata, Katsuya; Hagiwara, Koichi; Umezaki, Toshiro; Kenjo, Masamutsu; Nakagawa, Takashi; Tobimatsu, Shozo

    2017-02-01

    In a previous magnetoencephalographic study, we showed both functional and structural reorganization of the right auditory cortex and impaired left auditory cortex function in people who stutter (PWS). In the present work, we reevaluated the same dataset to further investigate how the right and left auditory cortices interact to compensate for stuttering. We evaluated bilateral N100m latencies as well as indices of local and inter-hemispheric phase synchronization of the auditory cortices. The left N100m latency was significantly prolonged relative to the right N100m latency in PWS, while healthy control participants did not show any inter-hemispheric differences in latency. A phase-locking factor (PLF) analysis, which indicates the degree of local phase synchronization, demonstrated enhanced alpha-band synchrony in the right auditory area of PWS. A phase-locking value (PLV) analysis of inter-hemispheric synchronization demonstrated significant elevations in the beta band between the right and left auditory cortices in PWS. In addition, right PLF and PLVs were positively correlated with stuttering frequency in PWS. Taken together, our data suggest that increased right hemispheric local phase synchronization and increased inter-hemispheric phase synchronization are electrophysiological correlates of a compensatory mechanism for impaired left auditory processing in PWS. Published by Elsevier B.V.

  4. Spontaneous synchronized tapping to an auditory rhythm in a chimpanzee.

    Science.gov (United States)

    Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

    2013-01-01

    Humans actively use behavioral synchrony such as dancing and singing when they intend to make affiliative relationships. Such advanced synchronous movement occurs even unconsciously when we hear rhythmically complex music. A foundation for this tendency may be an evolutionary adaptation for group living but evolutionary origins of human synchronous activity is unclear. Here we show the first evidence that a member of our closest living relatives, a chimpanzee, spontaneously synchronizes her movement with an auditory rhythm: After a training to tap illuminated keys on an electric keyboard, one chimpanzee spontaneously aligned her tapping with the sound when she heard an isochronous distractor sound. This result indicates that sensitivity to, and tendency toward synchronous movement with an auditory rhythm exist in chimpanzees, although humans may have expanded it to unique forms of auditory and visual communication during the course of human evolution.

  5. Neural correlates of auditory temporal predictions during sensorimotor synchronization

    Directory of Open Access Journals (Sweden)

    Nadine ePecenka

    2013-08-01

    Full Text Available Musical ensemble performance requires temporally precise interpersonal action coordination. To play in synchrony, ensemble musicians presumably rely on anticipatory mechanisms that enable them to predict the timing of sounds produced by co-performers. Previous studies have shown that individuals differ in their ability to predict upcoming tempo changes in paced finger-tapping tasks (indexed by cross-correlations between tap timing and pacing events and that the degree of such prediction influences the accuracy of sensorimotor synchronization (SMS and interpersonal coordination in dyadic tapping tasks. The current functional magnetic resonance imaging study investigated the neural correlates of auditory temporal predictions during SMS in a within-subject design. Hemodynamic responses were recorded from 18 musicians while they tapped in synchrony with auditory sequences containing gradual tempo changes under conditions of varying cognitive load (achieved by a simultaneous visual n-back working-memory task comprising three levels of difficulty: observation only, 1-back, and 2-back object comparisons. Prediction ability during SMS decreased with increasing cognitive load. Results of a parametric analysis revealed that the generation of auditory temporal predictions during SMS recruits (1 a distributed network in cortico-cerebellar motor-related brain areas (left dorsal premotor and motor cortex, right lateral cerebellum, SMA proper and bilateral inferior parietal cortex and (2 medial cortical areas (medial prefrontal cortex, posterior cingulate cortex. While the first network is presumably involved in basic sensory prediction, sensorimotor integration, motor timing, and temporal adaptation, activation in the second set of areas may be related to higher-level social-cognitive processes elicited during action coordination with auditory signals that resemble music performed by human agents.

  6. Neural correlates of auditory temporal predictions during sensorimotor synchronization.

    Science.gov (United States)

    Pecenka, Nadine; Engel, Annerose; Keller, Peter E

    2013-01-01

    Musical ensemble performance requires temporally precise interpersonal action coordination. To play in synchrony, ensemble musicians presumably rely on anticipatory mechanisms that enable them to predict the timing of sounds produced by co-performers. Previous studies have shown that individuals differ in their ability to predict upcoming tempo changes in paced finger-tapping tasks (indexed by cross-correlations between tap timing and pacing events) and that the degree of such prediction influences the accuracy of sensorimotor synchronization (SMS) and interpersonal coordination in dyadic tapping tasks. The current functional magnetic resonance imaging study investigated the neural correlates of auditory temporal predictions during SMS in a within-subject design. Hemodynamic responses were recorded from 18 musicians while they tapped in synchrony with auditory sequences containing gradual tempo changes under conditions of varying cognitive load (achieved by a simultaneous visual n-back working-memory task comprising three levels of difficulty: observation only, 1-back, and 2-back object comparisons). Prediction ability during SMS decreased with increasing cognitive load. Results of a parametric analysis revealed that the generation of auditory temporal predictions during SMS recruits (1) a distributed network of cortico-cerebellar motor-related brain areas (left dorsal premotor and motor cortex, right lateral cerebellum, SMA proper and bilateral inferior parietal cortex) and (2) medial cortical areas (medial prefrontal cortex, posterior cingulate cortex). While the first network is presumably involved in basic sensory prediction, sensorimotor integration, motor timing, and temporal adaptation, activation in the second set of areas may be related to higher-level social-cognitive processes elicited during action coordination with auditory signals that resemble music performed by human agents.

  7. Electrotonic vascular signal conduction and nephron synchronization

    DEFF Research Database (Denmark)

    Marsh, D.J.; Toma, I.; Sosnovtseva, Olga

    2009-01-01

    frequencies of both pair members to converge to a common value. The myogenic oscillations also synchronized, and the synchronization between the TGF and the myogenic oscillations showed an increased stability against parameter perturbations. Electronic vascular signal propagation is a plausible mechanism...

  8. Synchronization and phonological skills: precise auditory timing hypothesis (PATH

    Directory of Open Access Journals (Sweden)

    Adam eTierney

    2014-11-01

    Full Text Available Phonological skills are enhanced by music training, but the mechanisms enabling this cross-domain enhancement remain unknown. To explain this cross-domain transfer, we propose a precise auditory timing hypothesis (PATH whereby entrainment practice is the core mechanism underlying enhanced phonological abilities in musicians. Both rhythmic synchronization and language skills such as consonant discrimination, detection of word and phrase boundaries, and conversational turn-taking rely on the perception of extremely fine-grained timing details in sound. Auditory-motor timing is an acoustic feature which meets all five of the pre-conditions necessary for cross-domain enhancement to occur (Patel 2011, 2012, 2014. There is overlap between the neural networks that process timing in the context of both music and language. Entrainment to music demands more precise timing sensitivity than does language processing. Moreover, auditory-motor timing integration captures the emotion of the trainee, is repeatedly practiced, and demands focused attention. The precise auditory timing hypothesis predicts that musical training emphasizing entrainment will be particularly effective in enhancing phonological skills.

  9. Neural synchronization via potassium signaling

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Mosekilde, Erik

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature of this reso...

  10. Neural Synchronization via Potassium Signaling,

    DEFF Research Database (Denmark)

    Postnov, D. E.; Ryazanova, L. S.; Sosnovtseva, Olga

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature of this reso...

  11. Phase synchronization of instrumental music signals

    Science.gov (United States)

    Mukherjee, Sayan; Palit, Sanjay Kumar; Banerjee, Santo; Ariffin, M. R. K.; Bhattacharya, D. K.

    2014-06-01

    Signal analysis is one of the finest scientific techniques in communication theory. Some quantitative and qualitative measures describe the pattern of a music signal, vary from one to another. Same musical recital, when played by different instrumentalists, generates different types of music patterns. The reason behind various patterns is the psycho-acoustic measures - Dynamics, Timber, Tonality and Rhythm, varies in each time. However, the psycho-acoustic study of the music signals does not reveal any idea about the similarity between the signals. For such cases, study of synchronization of long-term nonlinear dynamics may provide effective results. In this context, phase synchronization (PS) is one of the measures to show synchronization between two non-identical signals. In fact, it is very critical to investigate any other kind of synchronization for experimental condition, because those are completely non identical signals. Also, there exists equivalence between the phases and the distances of the diagonal line in Recurrence plot (RP) of the signals, which is quantifiable by the recurrence quantification measure τ-recurrence rate. This paper considers two nonlinear music signals based on same raga played by two eminent sitar instrumentalists as two non-identical sources. The psycho-acoustic study shows how the Dynamics, Timber, Tonality and Rhythm vary for the two music signals. Then, long term analysis in the form of phase space reconstruction is performed, which reveals the chaotic phase spaces for both the signals. From the RP of both the phase spaces, τ-recurrence rate is calculated. Finally by the correlation of normalized tau-recurrence rate of their 3D phase spaces and the PS of the two music signals has been established. The numerical results well support the analysis.

  12. Gymnasts utilize visual and auditory information for behavioural synchronization in trampolining.

    Science.gov (United States)

    Heinen, T; Koschnick, J; Schmidt-Maaß, D; Vinken, P M

    2014-08-01

    In synchronized trampolining, two gymnasts perform the same routine at the same time. While trained gymnasts are thought to coordinate their own movements with the movements of another gymnast by detecting relevant movement information, the question arises how visual and auditory information contribute to the emergence of synchronicity between both gymnasts. Therefore the aim of this study was to examine the role of visual and auditory information in the emergence of coordinated behaviour in synchronized trampolining. Twenty female gymnasts were asked to synchronize their leaps with the leaps of a model gymnast, while visual and auditory information was manipulated. The results revealed that gymnasts needed more leaps to reach synchronicity when only either auditory (12.9 leaps) or visual information (10.8 leaps) was available, as compared to when both auditory and visual information was available (8.1 leaps). It is concluded that visual and auditory information play significant roles in synchronized trampolining, whilst visual information seems to be the dominant source for emerging behavioural synchronization, and auditory information supports this emergence.

  13. Temporal expectation weights visual signals over auditory signals.

    Science.gov (United States)

    Menceloglu, Melisa; Grabowecky, Marcia; Suzuki, Satoru

    2017-04-01

    Temporal expectation is a process by which people use temporally structured sensory information to explicitly or implicitly predict the onset and/or the duration of future events. Because timing plays a critical role in crossmodal interactions, we investigated how temporal expectation influenced auditory-visual interaction, using an auditory-visual crossmodal congruity effect as a measure of crossmodal interaction. For auditory identification, an incongruent visual stimulus produced stronger interference when the crossmodal stimulus was presented with an expected rather than an unexpected timing. In contrast, for visual identification, an incongruent auditory stimulus produced weaker interference when the crossmodal stimulus was presented with an expected rather than an unexpected timing. The fact that temporal expectation made visual distractors more potent and visual targets less susceptible to auditory interference suggests that temporal expectation increases the perceptual weight of visual signals.

  14. Synchronization to auditory and visual rhythms in hearing and deaf individuals

    Science.gov (United States)

    Iversen, John R.; Patel, Aniruddh D.; Nicodemus, Brenda; Emmorey, Karen

    2014-01-01

    A striking asymmetry in human sensorimotor processing is that humans synchronize movements to rhythmic sound with far greater precision than to temporally equivalent visual stimuli (e.g., to an auditory vs. a flashing visual metronome). Traditionally, this finding is thought to reflect a fundamental difference in auditory vs. visual processing, i.e., superior temporal processing by the auditory system and/or privileged coupling between the auditory and motor systems. It is unclear whether this asymmetry is an inevitable consequence of brain organization or whether it can be modified (or even eliminated) by stimulus characteristics or by experience. With respect to stimulus characteristics, we found that a moving, colliding visual stimulus (a silent image of a bouncing ball with a distinct collision point on the floor) was able to drive synchronization nearly as accurately as sound in hearing participants. To study the role of experience, we compared synchronization to flashing metronomes in hearing and profoundly deaf individuals. Deaf individuals performed better than hearing individuals when synchronizing with visual flashes, suggesting that cross-modal plasticity enhances the ability to synchronize with temporally discrete visual stimuli. Furthermore, when deaf (but not hearing) individuals synchronized with the bouncing ball, their tapping patterns suggest that visual timing may access higher-order beat perception mechanisms for deaf individuals. These results indicate that the auditory advantage in rhythmic synchronization is more experience- and stimulus-dependent than has been previously reported. PMID:25460395

  15. Auditory presentation and synchronization in Adobe Flash and HTML5/JavaScript Web experiments.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2016-09-01

    Substantial recent research has examined the accuracy of presentation durations and response time measurements for visually presented stimuli in Web-based experiments, with a general conclusion that accuracy is acceptable for most kinds of experiments. However, many areas of behavioral research use auditory stimuli instead of, or in addition to, visual stimuli. Much less is known about auditory accuracy using standard Web-based testing procedures. We used a millisecond-accurate Black Box Toolkit to measure the actual durations of auditory stimuli and the synchronization of auditory and visual presentation onsets. We examined the distribution of timings for 100 presentations of auditory and visual stimuli across two computers with difference specs, three commonly used browsers, and code written in either Adobe Flash or JavaScript. We also examined different coding options for attempting to synchronize the auditory and visual onsets. Overall, we found that auditory durations were very consistent, but that the lags between visual and auditory onsets varied substantially across browsers and computer systems.

  16. Auditory signal design for automatic number plate recognition system

    NARCIS (Netherlands)

    Heydra, C.G.; Jansen, R.J.; Van Egmond, R.

    2014-01-01

    This paper focuses on the design of an auditory signal for the Automatic Number Plate Recognition system of Dutch national police. The auditory signal is designed to alert police officers of suspicious cars in their proximity, communicating priority level and location of the suspicious car and

  17. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    OpenAIRE

    Masahiro eKawasaki; Masahiro eKawasaki; Masahiro eKawasaki; Keiichi eKitajo; Keiichi eKitajo; Yoko eYamaguchi

    2014-01-01

    In humans, theta phase (4–8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from...

  18. Entrainment to an auditory signal: Is attention involved?

    NARCIS (Netherlands)

    Kunert, R.; Jongman, S.R.

    2017-01-01

    Many natural auditory signals, including music and language, change periodically. The effect of such auditory rhythms on the brain is unclear however. One widely held view, dynamic attending theory, proposes that the attentional system entrains to the rhythm and increases attention at moments of

  19. Fading of radio signals from spaced synchronous satellites ...

    African Journals Online (AJOL)

    The fading of radio signals from synchronous satellites has been investigated, by analyzing the fading records radiated from a system of spaced synchronous satellites, all radiating at 136 MHz, and observed at Legon, Ghana: longitude 0.19° west, latitude 5.63° north and magnetic dip 8.47° south; for the occurrence of ...

  20. Pitch Synchronous Segmentation of Speech Signals

    Data.gov (United States)

    National Aeronautics and Space Administration — The Pitch Synchronous Segmentation (PSS) that accelerates speech without changing its fundamental frequency method could be applied and evaluated for use at NASA....

  1. Working Memory and Auditory Imagery Predict Sensorimotor Synchronization with Expressively Timed Music.

    Science.gov (United States)

    Colley, Ian D; Keller, Peter E; Halpern, Andrea R

    2017-08-11

    Sensorimotor synchronization (SMS) is prevalent and readily studied in musical settings, as most people are able to perceive and synchronize with a beat (e.g. by finger tapping). We took an individual differences approach to understanding SMS to real music characterized by expressive timing (i.e. fluctuating beat regularity). Given the dynamic nature of SMS, we hypothesized that individual differences in working memory and auditory imagery-both fluid cognitive processes-would predict SMS at two levels: 1) mean absolute asynchrony (a measure of synchronization error), and 2) anticipatory timing (i.e. predicting, rather than reacting to beat intervals). In Experiment 1, participants completed two working memory tasks, four auditory imagery tasks, and an SMS-tapping task. Hierarchical regression models were used to predict SMS performance, with results showing dissociations among imagery types in relation to mean absolute asynchrony, and evidence of a role for working memory in anticipatory timing. In Experiment 2, a new sample of participants completed an expressive timing perception task to examine the role of imagery in perception without action. Results suggest that imagery vividness is important for perceiving and control is important for synchronizing with, irregular but ecologically valid musical time series. Working memory is implicated in synchronizing by anticipating events in the series.

  2. A virtual auditory environment for investigating the auditory signal processing of realistic sounds

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2008-01-01

    In the present study, a novel multichannel loudspeaker-based virtual auditory environment (VAE) is introduced. The VAE aims at providing a versatile research environment for investigating the auditory signal processing in real environments, i.e., considering multiple sound sources and room...... of the mRIR with an acoustic signal. The derivation of the mRIRs takes into account that (i) auditory localization is most sensitive to the location of the direct sound and (ii) that auditory localization performance is rather poor for early reflections and even worse for late reverberation. Throughout...... the VAE development, special care was taken in order to achieve a realistic auditory percept and to avoid “artifacts” such as unnatural coloration. The performance of the VAE has been evaluated and optimized on a 29 loudspeaker setup using both objective and subjective measurement techniques....

  3. Auditory Pattern Memory and Group Signal Detection

    National Research Council Canada - National Science Library

    Sorkin, Robert

    1997-01-01

    .... The experiments with temporally-coded auditory patterns showed how listeners' attention is influenced by the position and the amount of information carried by different segments of the pattern...

  4. Size and synchronization of auditory cortex promotes musical, literacy, and attentional skills in children.

    Science.gov (United States)

    Seither-Preisler, Annemarie; Parncutt, Richard; Schneider, Peter

    2014-08-13

    Playing a musical instrument is associated with numerous neural processes that continuously modify the human brain and may facilitate characteristic auditory skills. In a longitudinal study, we investigated the auditory and neural plasticity of musical learning in 111 young children (aged 7-9 y) as a function of the intensity of instrumental practice and musical aptitude. Because of the frequent co-occurrence of central auditory processing disorders and attentional deficits, we also tested 21 children with attention deficit (hyperactivity) disorder [AD(H)D]. Magnetic resonance imaging and magnetoencephalography revealed enlarged Heschl's gyri and enhanced right-left hemispheric synchronization of the primary evoked response (P1) to harmonic complex sounds in children who spent more time practicing a musical instrument. The anatomical characteristics were positively correlated with frequency discrimination, reading, and spelling skills. Conversely, AD(H)D children showed reduced volumes of Heschl's gyri and enhanced volumes of the plana temporalia that were associated with a distinct bilateral P1 asynchrony. This may indicate a risk for central auditory processing disorders that are often associated with attentional and literacy problems. The longitudinal comparisons revealed a very high stability of auditory cortex morphology and gray matter volumes, suggesting that the combined anatomical and functional parameters are neural markers of musicality and attention deficits. Educational and clinical implications are considered. Copyright © 2014 the authors 0270-6474/14/3410937-13$15.00/0.

  5. A virtual auditory environment for investigating the auditory signal processing of realistic sounds

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel

    A loudspeaker-based virtual auditory environment (VAE) has been developed to provide a realistic versatile research environment for investigating the auditory signal processing in real environments, i.e., considering multiple sound sources and room reverberation. The VAE allows a full control...... of the acoustic scenario in order to systematically study the auditory processing of reverberant sounds. It is based on the ODEON software, which is state-of-the-art software for room acoustic simulations developed at Acoustic Technology, DTU. First, a MATLAB interface to the ODEON software has been developed...

  6. Synchronous Modeling of Modular Avionics Architectures using the SIGNAL Language

    OpenAIRE

    Gamatié , Abdoulaye; Gautier , Thierry

    2002-01-01

    This document presents a study on the modeling of architecture components for avionics applications. We consider the avionics standard ARINC 653 specifications as basis, as well as the synchronous language SIGNAL to describe the modeling. A library of APEX object models (partition, process, communication and synchronization services, etc.) has been implemented. This should allow to describe distributed real-time applications using POLYCHRONY, so as to access formal tools and techniques for ar...

  7. Condition monitoring of gearboxes using synchronously averaged electric motor signals

    Science.gov (United States)

    Ottewill, J. R.; Orkisz, M.

    2013-07-01

    Due to their prevalence in rotating machinery, the condition monitoring of gearboxes is extremely important in the minimization of potentially dangerous and expensive failures. Traditionally, gearbox condition monitoring has been conducted using measurements obtained from casing-mounted vibration transducers such as accelerometers. A well-established technique for analyzing such signals is the synchronous signal average, where vibration signals are synchronized to a measured angular position and then averaged from rotation to rotation. Driven, in part, by improvements in control methodologies based upon methods of estimating rotor speed and torque, induction machines are used increasingly in industry to drive rotating machinery. As a result, attempts have been made to diagnose defects using measured terminal currents and voltages. In this paper, the application of the synchronous signal averaging methodology to electric drive signals, by synchronizing stator current signals with a shaft position estimated from current and voltage measurements is proposed. Initially, a test-rig is introduced based on an induction motor driving a two-stage reduction gearbox which is loaded by a DC motor. It is shown that a defect seeded into the gearbox may be located using signals acquired from casing-mounted accelerometers and shaft mounted encoders. Using simple models of an induction motor and a gearbox, it is shown that it should be possible to observe gearbox defects in the measured stator current signal. A robust method of extracting the average speed of a machine from the current frequency spectrum, based on the location of sidebands of the power supply frequency due to rotor eccentricity, is presented. The synchronous signal averaging method is applied to the resulting estimations of rotor position and torsional vibration. Experimental results show that the method is extremely adept at locating gear tooth defects. Further results, considering different loads and different

  8. Sensory Entrainment Mechanisms in Auditory Perception: Neural Synchronization Cortico-Striatal Activation

    Science.gov (United States)

    Sameiro-Barbosa, Catia M.; Geiser, Eveline

    2016-01-01

    The auditory system displays modulations in sensitivity that can align with the temporal structure of the acoustic environment. This sensory entrainment can facilitate sensory perception and is particularly relevant for audition. Systems neuroscience is slowly uncovering the neural mechanisms underlying the behaviorally observed sensory entrainment effects in the human sensory system. The present article summarizes the prominent behavioral effects of sensory entrainment and reviews our current understanding of the neural basis of sensory entrainment, such as synchronized neural oscillations, and potentially, neural activation in the cortico-striatal system. PMID:27559306

  9. A deafening flash! Visual interference of auditory signal detection.

    Science.gov (United States)

    Fassnidge, Christopher; Cecconi Marcotti, Claudia; Freeman, Elliot

    2017-03-01

    In some people, visual stimulation evokes auditory sensations. How prevalent and how perceptually real is this? 22% of our neurotypical adult participants responded 'Yes' when asked whether they heard faint sounds accompanying flash stimuli, and showed significantly better ability to discriminate visual 'Morse-code' sequences. This benefit might arise from an ability to recode visual signals as sounds, thus taking advantage of superior temporal acuity of audition. In support of this, those who showed better visual relative to auditory sequence discrimination also had poorer auditory detection in the presence of uninformative visual flashes, though this was independent of awareness of visually-evoked sounds. Thus a visually-evoked auditory representation may occur subliminally and disrupt detection of real auditory signals. The frequent natural correlation between visual and auditory stimuli might explain the surprising prevalence of this phenomenon. Overall, our results suggest that learned correspondences between strongly correlated modalities may provide a precursor for some synaesthetic abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. EEG synchronization to modulated auditory tones in schizophrenia, schizoaffective disorder, and schizotypal personality disorder.

    Science.gov (United States)

    Brenner, Colleen A; Sporns, Olaf; Lysaker, Paul H; O'Donnell, Brian F

    2003-12-01

    The authors tested whether neural synchronization deficits were present in subjects with schizophrenia and schizotypal personality disorder. Amplitude-modulated tones were used to evaluate auditory steady-state evoked potential entrainment in a combined group of 21 subjects with schizophrenia or schizoaffective disorder, 11 subjects with schizotypal personality disorder, and 22 nonpsychiatric comparison subjects. The schizophrenia or schizoaffective disorder group exhibited decreased power compared to the schizotypal personality disorder and nonpsychiatric comparison groups. There were no differences between groups in N100 amplitude. Subjects with schizophrenia but not subjects with schizotypal personality disorder have deficits in steady-state responses to periodic stimuli, despite an intact response to sensory-evoked potentials (N100). These deficits reflect aberrant neural synchronization or resolution and may contribute to disturbed perceptual and cognitive integration in schizophrenia.

  11. Selection of the signal synchronization method in software GPS receivers

    Directory of Open Access Journals (Sweden)

    Vlada S. Sokolović

    2011-04-01

    Full Text Available Introduction This paper presents a critical analysis of the signal processing flow carried out in a software GPS receiver and a critical comparison of different architectures for signal processing within the GPS receiver. A model of software receivers is shown. Based on the displayed model, a receiver has been realized in the MATLAB software package, in which the simulations of signal processing were carried out. The aim of this paper is to demonstrate the advantages and disadvantages of different methods of the synchronization of signals in the receiver, and to propose a solution acceptable for possible implementation. The signal processing flow was observed from the input circuit to the extraction of the bits of the navigation message. The entire signal processing was performed on the L1 signal and the data collected by the input circuit SE4110. A radio signal from the satellite was accepted with the input circuit, filtered and translated into a digital form. The input circuit ends with the hardware of the receiver. A digital signal from the input circuit is brought into the PC Pentium 4 (AMD 3000 + where the receiver is realized in Matlab. Model of software GPS receiver The first level of processing is signal acquisition. Signal acquisition was realized using the cyclic convolution. The acquisition process was carried out by measuring signals from satellites, and these parameters are passed to the next level of processing. The next level was done by monitoring the synchronization signal and extracting the navigation message bits. On the basis of the detection of the navigation message the receiver calculates the position of a satellite and then, based on the position of the satellite, its own position. Tracking of GPS signal synchronization In order to select the most acceptable method of signal synchronization in the receiver, different methods of signal synchronization are compared. The early-late-DLL (Delay Lock Loop, TDL (Tau Dither Loop

  12. Joint Iterative Carrier Synchronization and Signal Detection Employing Expectation Maximization

    DEFF Research Database (Denmark)

    Zibar, Darko; de Carvalho, Luis Henrique Hecker; Estaran Tolosa, Jose Manuel

    2014-01-01

    . The algorithm is tested in a mixed line rate optical transmission scenario employing dual polarization 448 Gb/s 16-QAM signal surrounded by eight on-off keying channels in a 50 GHz grid. It is shown that joint carrier synchronization and data detection are more robust towards optical transmitter impairments...

  13. Generation of synchronized signal and pump pulses for an optical ...

    Indian Academy of Sciences (India)

    parametric amplification (OPA) utilizes instantaneous non-linear interaction of the signal and the pump beams, the performance of OPCPA system is expected to be highly sensitive to the temporal synchronization errors between them (required to be less than ~100 ps). One way to eliminate this problem is to derive the ...

  14. Synchronous Malignant Otitis Externa and Squamous Cell Carcinoma of the External Auditory Canal

    Directory of Open Access Journals (Sweden)

    R. Y. Chin

    2013-01-01

    Full Text Available Objectives. To discuss the management of a squamous cell carcinoma in the presence of malignant otitis externa. Study Design. We present only the third reported case in the literature of a synchronous tumour with malignant otitis externa in the literature. Methods. A case report and review of malignant otitis externa and squamous cell carcinomas of the external auditory canal are discussed. Results. A 66-year-old female is presented here with a 2-month history of a painful, discharging left ear refractory to standard antibiotic therapy. Computerised tomography, magnetic resonance imaging, technetium 99 m, and gallium citrate Ga67 scans were consistent with malignant otitis externa. Biopsy in the operating theatre revealed a synchronous squamous cell carcinoma of the external auditory canal. Primary resection of the tumour and surrounding tissues was performed with concomitant treatment with intravenous antibiotics. Conclusions. This is only the third case to be reported in the literature and highlights several important diagnostic and management issues of these two rare conditions. Both conditions may present in a similar manner on clinical assessment and radiological investigations. Aggressive management with surgical resection and treatment with appropriate intravenous antibiotics is necessary to give the best chance for cure.

  15. Entrainment to an auditory signal: Is attention involved?

    Science.gov (United States)

    Kunert, Richard; Jongman, Suzanne R

    2017-01-01

    Many natural auditory signals, including music and language, change periodically. The effect of such auditory rhythms on the brain is unclear however. One widely held view, dynamic attending theory, proposes that the attentional system entrains to the rhythm and increases attention at moments of rhythmic salience. In support, 2 experiments reported here show reduced response times to visual letter strings shown at auditory rhythm peaks, compared with rhythm troughs. However, we argue that an account invoking the entrainment of general attention should further predict rhythm entrainment to also influence memory for visual stimuli. In 2 pseudoword memory experiments we find evidence against this prediction. Whether a pseudoword is shown during an auditory rhythm peak or not is irrelevant for its later recognition memory in silence. Other attention manipulations, dividing attention and focusing attention, did result in a memory effect. This raises doubts about the suggested attentional nature of rhythm entrainment. We interpret our findings as support for auditory rhythm perception being based on auditory-motor entrainment, not general attention entrainment. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Contextual modulation of primary visual cortex by auditory signals.

    Science.gov (United States)

    Petro, L S; Paton, A T; Muckli, L

    2017-02-19

    Early visual cortex receives non-feedforward input from lateral and top-down connections (Muckli & Petro 2013 Curr. Opin. Neurobiol. 23, 195-201. (doi:10.1016/j.conb.2013.01.020)), including long-range projections from auditory areas. Early visual cortex can code for high-level auditory information, with neural patterns representing natural sound stimulation (Vetter et al. 2014 Curr. Biol. 24, 1256-1262. (doi:10.1016/j.cub.2014.04.020)). We discuss a number of questions arising from these findings. What is the adaptive function of bimodal representations in visual cortex? What type of information projects from auditory to visual cortex? What are the anatomical constraints of auditory information in V1, for example, periphery versus fovea, superficial versus deep cortical layers? Is there a putative neural mechanism we can infer from human neuroimaging data and recent theoretical accounts of cortex? We also present data showing we can read out high-level auditory information from the activation patterns of early visual cortex even when visual cortex receives simple visual stimulation, suggesting independent channels for visual and auditory signals in V1. We speculate which cellular mechanisms allow V1 to be contextually modulated by auditory input to facilitate perception, cognition and behaviour. Beyond cortical feedback that facilitates perception, we argue that there is also feedback serving counterfactual processing during imagery, dreaming and mind wandering, which is not relevant for immediate perception but for behaviour and cognition over a longer time frame.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Authors.

  17. The speech signal segmentation algorithm using pitch synchronous analysis

    Directory of Open Access Journals (Sweden)

    Amirgaliyev Yedilkhan

    2017-03-01

    Full Text Available Parameterization of the speech signal using the algorithms of analysis synchronized with the pitch frequency is discussed. Speech parameterization is performed by the average number of zero transitions function and the signal energy function. Parameterization results are used to segment the speech signal and to isolate the segments with stable spectral characteristics. Segmentation results can be used to generate a digital voice pattern of a person or be applied in the automatic speech recognition. Stages needed for continuous speech segmentation are described.

  18. The power of auditory-motor synchronization in sports: enhancing running performance by coupling cadence with the right beats.

    Science.gov (United States)

    Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

    2013-01-01

    Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants' cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants' cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli -which was most salient during the metronome condition- helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner's cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by auditory

  19. The power of auditory-motor synchronization in sports: enhancing running performance by coupling cadence with the right beats.

    Directory of Open Access Journals (Sweden)

    Robert Jan Bood

    Full Text Available Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1 a control condition without acoustic stimuli, 2 a metronome condition with a sequence of beeps matching participants' cadence (synchronization, and 3 a music condition with synchronous motivational music matched to participants' cadence (synchronization+motivation. Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-maximal running intensity. The beat of the stimuli -which was most salient during the metronome condition- helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps. These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner's cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by

  20. The Power of Auditory-Motor Synchronization in Sports: Enhancing Running Performance by Coupling Cadence with the Right Beats

    Science.gov (United States)

    Bood, Robert Jan; Nijssen, Marijn; van der Kamp, John; Roerdink, Melvyn

    2013-01-01

    Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our objective was to examine the relative effects of auditory-motor synchronization and the motivational impact of acoustic stimuli on running performance. To this end, 19 participants ran to exhaustion on a treadmill in 1) a control condition without acoustic stimuli, 2) a metronome condition with a sequence of beeps matching participants’ cadence (synchronization), and 3) a music condition with synchronous motivational music matched to participants’ cadence (synchronization+motivation). Conditions were counterbalanced and measurements were taken on separate days. As expected, time to exhaustion was significantly longer with acoustic stimuli than without. Unexpectedly, however, time to exhaustion did not differ between metronome and motivational music conditions, despite differences in motivational quality. Motivational music slightly reduced perceived exertion of sub-maximal running intensity and heart rates of (near-)maximal running intensity. The beat of the stimuli –which was most salient during the metronome condition– helped runners to maintain a consistent pace by coupling cadence to the prescribed tempo. Thus, acoustic stimuli may have enhanced running performance because runners worked harder as a result of motivational aspects (most pronounced with motivational music) and more efficiently as a result of auditory-motor synchronization (most notable with metronome beeps). These findings imply that running to motivational music with a very prominent and consistent beat matched to the runner’s cadence will likely yield optimal effects because it helps to elevate physiological effort at a high perceived exertion, whereas the consistent and correct cadence induced by

  1. The power of auditory-motor synchronization in sports: Enhancing running performance by coupling cadence with the right beats

    NARCIS (Netherlands)

    Bood, R.J.; Nijssen, M; van der Kamp, J.; Roerdink, M.

    2013-01-01

    Acoustic stimuli, like music and metronomes, are often used in sports. Adjusting movement tempo to acoustic stimuli (i.e., auditory-motor synchronization) may be beneficial for sports performance. However, music also possesses motivational qualities that may further enhance performance. Our

  2. Motor-related signals in the auditory system for listening and learning.

    Science.gov (United States)

    Schneider, David M; Mooney, Richard

    2015-08-01

    In the auditory system, corollary discharge signals are theorized to facilitate normal hearing and the learning of acoustic behaviors, including speech and music. Despite clear evidence of corollary discharge signals in the auditory cortex and their presumed importance for hearing and auditory-guided motor learning, the circuitry and function of corollary discharge signals in the auditory cortex are not well described. In this review, we focus on recent developments in the mouse and songbird that provide insights into the circuitry that transmits corollary discharge signals to the auditory system and the function of these signals in the context of hearing and vocal learning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Video Synchronization With Bit-Rate Signals and Correntropy Function

    Directory of Open Access Journals (Sweden)

    Igor Pereira

    2017-09-01

    Full Text Available We propose an approach for the synchronization of video streams using correntropy. Essentially, the time offset is calculated on the basis of the instantaneous transfer rates of the video streams that are extracted in the form of a univariate signal known as variable bit-rate (VBR. The state-of-the-art approach uses a window segmentation strategy that is based on consensual zero-mean normalized cross-correlation (ZNCC. This strategy has an elevated computational complexity, making its application to synchronizing online data streaming difficult. Hence, our proposal uses a different window strategy that, together with the correntropy function, allows the synchronization to be performed for online applications. This provides equivalent synchronization scores with a rapid offset determination as the streams come into the system. The efficiency of our approach has been verified through experiments that demonstrate its viability with values that are as precise as those obtained by ZNCC. The proposed approach scored 81 % in time reference classification against the equivalent 81 % of the state-of-the-art approach, requiring much less computational power.

  4. Video Synchronization With Bit-Rate Signals and Correntropy Function.

    Science.gov (United States)

    Pereira, Igor; Silveira, Luiz F; Gonçalves, Luiz

    2017-09-04

    We propose an approach for the synchronization of video streams using correntropy. Essentially, the time offset is calculated on the basis of the instantaneous transfer rates of the video streams that are extracted in the form of a univariate signal known as variable bit-rate (VBR). The state-of-the-art approach uses a window segmentation strategy that is based on consensual zero-mean normalized cross-correlation (ZNCC). This strategy has an elevated computational complexity, making its application to synchronizing online data streaming difficult. Hence, our proposal uses a different window strategy that, together with the correntropy function, allows the synchronization to be performed for online applications. This provides equivalent synchronization scores with a rapid offset determination as the streams come into the system. The efficiency of our approach has been verified through experiments that demonstrate its viability with values that are as precise as those obtained by ZNCC. The proposed approach scored 81 % in time reference classification against the equivalent 81 % of the state-of-the-art approach, requiring much less computational power.

  5. A computational model of human auditory signal processing and perception

    OpenAIRE

    Jepsen, Morten Løve; Ewert, Stephan D.; Dau, Torsten

    2008-01-01

    A model of computational auditory signal-processing and perception that accounts for various aspects of simultaneous and nonsimultaneous masking in human listeners is presented. The model is based on the modulation filterbank model described by Dau et al. [J. Acoust. Soc. Am. 102, 2892 (1997)] but includes major changes at the peripheral and more central stages of processing. The model contains outer- and middle-ear transformations, a nonlinear basilar-membrane processing stage, a hair-cell t...

  6. A basic study on universal design of auditory signals in automobiles.

    Science.gov (United States)

    Yamauchi, Katsuya; Choi, Jong-dae; Maiguma, Ryo; Takada, Masayuki; Iwamiya, Shin-ichiro

    2004-11-01

    In this paper, the impression of various kinds of auditory signals currently used in automobiles and a comprehensive evaluation were measured by a semantic differential method. The desirable acoustic characteristic was examined for each type of auditory signal. Sharp sounds with dominant high-frequency components were not suitable for auditory signals in automobiles. This trend is expedient for the aged whose auditory sensitivity in the high frequency region is lower. When intermittent sounds were used, a longer OFF time was suitable. Generally, "dull (not sharp)" and "calm" sounds were appropriate for auditory signals. Furthermore, the comparison between the frequency spectrum of interior noise in automobiles and that of suitable sounds for various auditory signals indicates that the suitable sounds are not easily masked. The suitable auditory signals for various purposes is a good solution from the viewpoint of universal design.

  7. Inhibitory network interactions shape the auditory processing of natural communication signals in the songbird auditory forebrain.

    Science.gov (United States)

    Pinaud, Raphael; Terleph, Thomas A; Tremere, Liisa A; Phan, Mimi L; Dagostin, André A; Leão, Ricardo M; Mello, Claudio V; Vicario, David S

    2008-07-01

    The role of GABA in the central processing of complex auditory signals is not fully understood. We have studied the involvement of GABA A-mediated inhibition in the processing of birdsong, a learned vocal communication signal requiring intact hearing for its development and maintenance. We focused on caudomedial nidopallium (NCM), an area analogous to parts of the mammalian auditory cortex with selective responses to birdsong. We present evidence that GABA A-mediated inhibition plays a pronounced role in NCM's auditory processing of birdsong. Using immunocytochemistry, we show that approximately half of NCM's neurons are GABAergic. Whole cell patch-clamp recordings in a slice preparation demonstrate that, at rest, spontaneously active GABAergic synapses inhibit excitatory inputs onto NCM neurons via GABA A receptors. Multi-electrode electrophysiological recordings in awake birds show that local blockade of GABA A-mediated inhibition in NCM markedly affects the temporal pattern of song-evoked responses in NCM without modifications in frequency tuning. Surprisingly, this blockade increases the phasic and largely suppresses the tonic response component, reflecting dynamic relationships of inhibitory networks that could include disinhibition. Thus processing of learned natural communication sounds in songbirds, and possibly other vocal learners, may depend on complex interactions of inhibitory networks.

  8. Atypical Bilateral Brain Synchronization in the Early Stage of Human Voice Auditory Processing in Young Children with Autism.

    Directory of Open Access Journals (Sweden)

    Toshiharu Kurita

    Full Text Available Autism spectrum disorder (ASD has been postulated to involve impaired neuronal cooperation in large-scale neural networks, including cortico-cortical interhemispheric circuitry. In the context of ASD, alterations in both peripheral and central auditory processes have also attracted a great deal of interest because these changes appear to represent pathophysiological processes; therefore, many prior studies have focused on atypical auditory responses in ASD. The auditory evoked field (AEF, recorded by magnetoencephalography, and the synchronization of these processes between right and left hemispheres was recently suggested to reflect various cognitive abilities in children. However, to date, no previous study has focused on AEF synchronization in ASD subjects. To assess global coordination across spatially distributed brain regions, the analysis of Omega complexity from multichannel neurophysiological data was proposed. Using Omega complexity analysis, we investigated the global coordination of AEFs in 3-8-year-old typically developing (TD children (n = 50 and children with ASD (n = 50 in 50-ms time-windows. Children with ASD displayed significantly higher Omega complexities compared with TD children in the time-window of 0-50 ms, suggesting lower whole brain synchronization in the early stage of the P1m component. When we analyzed the left and right hemispheres separately, no significant differences in any time-windows were observed. These results suggest lower right-left hemispheric synchronization in children with ASD compared with TD children. Our study provides new evidence of aberrant neural synchronization in young children with ASD by investigating auditory evoked neural responses to the human voice.

  9. Increased BOLD Signals Elicited by High Gamma Auditory Stimulation of the Left Auditory Cortex in Acute State Schizophrenia

    Directory of Open Access Journals (Sweden)

    Hironori Kuga, M.D.

    2016-10-01

    We acquired BOLD responses elicited by click trains of 20, 30, 40 and 80-Hz frequencies from 15 patients with acute episode schizophrenia (AESZ, 14 symptom-severity-matched patients with non-acute episode schizophrenia (NASZ, and 24 healthy controls (HC, assessed via a standard general linear-model-based analysis. The AESZ group showed significantly increased ASSR-BOLD signals to 80-Hz stimuli in the left auditory cortex compared with the HC and NASZ groups. In addition, enhanced 80-Hz ASSR-BOLD signals were associated with more severe auditory hallucination experiences in AESZ participants. The present results indicate that neural over activation occurs during 80-Hz auditory stimulation of the left auditory cortex in individuals with acute state schizophrenia. Given the possible association between abnormal gamma activity and increased glutamate levels, our data may reflect glutamate toxicity in the auditory cortex in the acute state of schizophrenia, which might lead to progressive changes in the left transverse temporal gyrus.

  10. A computational model of human auditory signal processing and perception

    DEFF Research Database (Denmark)

    Jepsen, Morten Løve; Ewert, Stephan D.; Dau, Torsten

    2008-01-01

    A model of computational auditory signal-processing and perception that accounts for various aspects of simultaneous and nonsimultaneous masking in human listeners is presented. The model is based on the modulation filterbank model described by Dau et al. [J. Acoust. Soc. Am. 102, 2892 (1997...... discrimination with pure tones and broadband noise, tone-in-noise detection, spectral masking with narrow-band signals and maskers, forward masking with tone signals and tone or noise maskers, and amplitude-modulation detection with narrow- and wideband noise carriers. The model can account for most of the key...... properties of the data and is more powerful than the original model. The model might be useful as a front end in technical applications....

  11. A computational model of human auditory signal processing and perception.

    Science.gov (United States)

    Jepsen, Morten L; Ewert, Stephan D; Dau, Torsten

    2008-07-01

    A model of computational auditory signal-processing and perception that accounts for various aspects of simultaneous and nonsimultaneous masking in human listeners is presented. The model is based on the modulation filterbank model described by Dau et al. [J. Acoust. Soc. Am. 102, 2892 (1997)] but includes major changes at the peripheral and more central stages of processing. The model contains outer- and middle-ear transformations, a nonlinear basilar-membrane processing stage, a hair-cell transduction stage, a squaring expansion, an adaptation stage, a 150-Hz lowpass modulation filter, a bandpass modulation filterbank, a constant-variance internal noise, and an optimal detector stage. The model was evaluated in experimental conditions that reflect, to a different degree, effects of compression as well as spectral and temporal resolution in auditory processing. The experiments include intensity discrimination with pure tones and broadband noise, tone-in-noise detection, spectral masking with narrow-band signals and maskers, forward masking with tone signals and tone or noise maskers, and amplitude-modulation detection with narrow- and wideband noise carriers. The model can account for most of the key properties of the data and is more powerful than the original model. The model might be useful as a front end in technical applications.

  12. Synchronized Progression of Prestin Expression and Auditory Brainstem Response during Postnatal Development in Rats

    Directory of Open Access Journals (Sweden)

    Jianfeng Hang

    2016-01-01

    Full Text Available Prestin is the motor protein expressed in the cochlear outer hair cells (OHCs of mammalian inner ear. The electromotility of OHCs driven by prestin is responsible for the cochlear amplification which is required for normal hearing in adult animals. Postnatal expression of prestin and activity of OHCs may contribute to the maturation of hearing in rodents. However, the temporal and spatial expression of prestin in cochlea during the development is not well characterized. In the present study, we examined the expression and function of prestin from the OHCs in apical, middle, and basal turns of the cochleae of postnatal rats. Prestin first appeared at postnatal day 6 (P6 for basal turn, P7 in middle turn, and P9 for apical turn of cochlea. The expression level increased progressively over the next few days and by P14 reached the mature level for all three segments. By comparison with the time course of the development of auditory brainstem response for different frequencies, our data reveal that prestin expression synchronized with the hearing development. The present study suggests that the onset time of hearing may require the expression of prestin and is determined by the mature function of OHCs.

  13. Lag synchronization of Rossler system and Chua circuit via a scalar signal

    International Nuclear Information System (INIS)

    Li Chuandong; Liao Xiaofeng

    2004-01-01

    In this Letter, a chaotic lag synchronization scheme is proposed based on combining a nonlinear with lag-in-time observer design. Our approach leads to a systematic methodology, which guarantees the synchronization of a wide class of chaotic systems via a scalar signal. The proposed technique has been applied to synchronize two well-known chaotic systems: Rossler's system and Chua circuit

  14. A hardware model of the auditory periphery to transduce acoustic signals into neural activity

    Directory of Open Access Journals (Sweden)

    Takashi eTateno

    2013-11-01

    Full Text Available To improve the performance of cochlear implants, we have integrated a microdevice into a model of the auditory periphery with the goal of creating a microprocessor. We constructed an artificial peripheral auditory system using a hybrid model in which polyvinylidene difluoride was used as a piezoelectric sensor to convert mechanical stimuli into electric signals. To produce frequency selectivity, the slit on a stainless steel base plate was designed such that the local resonance frequency of the membrane over the slit reflected the transfer function. In the acoustic sensor, electric signals were generated based on the piezoelectric effect from local stress in the membrane. The electrodes on the resonating plate produced relatively large electric output signals. The signals were fed into a computer model that mimicked some functions of inner hair cells, inner hair cell–auditory nerve synapses, and auditory nerve fibers. In general, the responses of the model to pure-tone burst and complex stimuli accurately represented the discharge rates of high-spontaneous-rate auditory nerve fibers across a range of frequencies greater than 1 kHz and middle to high sound pressure levels. Thus, the model provides a tool to understand information processing in the peripheral auditory system and a basic design for connecting artificial acoustic sensors to the peripheral auditory nervous system. Finally, we discuss the need for stimulus control with an appropriate model of the auditory periphery based on auditory brainstem responses that were electrically evoked by different temporal pulse patterns with the same pulse number.

  15. Tap Arduino: An Arduino microcontroller for low-latency auditory feedback in sensorimotor synchronization experiments.

    Science.gov (United States)

    Schultz, Benjamin G; van Vugt, Floris T

    2016-12-01

    Timing abilities are often measured by having participants tap their finger along with a metronome and presenting tap-triggered auditory feedback. These experiments predominantly use electronic percussion pads combined with software (e.g., FTAP or Max/MSP) that records responses and delivers auditory feedback. However, these setups involve unknown latencies between tap onset and auditory feedback and can sometimes miss responses or record multiple, superfluous responses for a single tap. These issues may distort measurements of tapping performance or affect the performance of the individual. We present an alternative setup using an Arduino microcontroller that addresses these issues and delivers low-latency auditory feedback. We validated our setup by having participants (N = 6) tap on a force-sensitive resistor pad connected to the Arduino and on an electronic percussion pad with various levels of force and tempi. The Arduino delivered auditory feedback through a pulse-width modulation (PWM) pin connected to a headphone jack or a wave shield component. The Arduino's PWM (M = 0.6 ms, SD = 0.3) and wave shield (M = 2.6 ms, SD = 0.3) demonstrated significantly lower auditory feedback latencies than the percussion pad (M = 9.1 ms, SD = 2.0), FTAP (M = 14.6 ms, SD = 2.8), and Max/MSP (M = 15.8 ms, SD = 3.4). The PWM and wave shield latencies were also significantly less variable than those from FTAP and Max/MSP. The Arduino missed significantly fewer taps, and recorded fewer superfluous responses, than the percussion pad. The Arduino captured all responses, whereas at lower tapping forces, the percussion pad missed more taps. Regardless of tapping force, the Arduino outperformed the percussion pad. Overall, the Arduino is a high-precision, low-latency, portable, and affordable tool for auditory experiments.

  16. A new class of auditory warning signals for complex systems: auditory icons.

    Science.gov (United States)

    Belz, S M; Robinson, G S; Casali, J G

    1999-12-01

    This simulator-based study examined conventional auditory warnings (tonal, nonverbal sounds) and auditory icons (representational, nonverbal sounds), alone and in combination with a dash-mounted visual display, to present information about impending collision situations to commercial motor vehicle operators. Brake response times were measured for impending front-to-rear collision scenarios under 6 display configurations, 2 vehicle speeds, and 2 levels of headway. Accident occurrence was measured for impending side collision scenarios under 2 vehicle speeds, 2 levels of visual workload, 2 auditory displays, absence/presence of mirrors, and absence/presence of a dash-mounted iconic visual display. For both front-to-rear and side collision scenarios, auditory icons elicited significantly improved driver performance over conventional auditory warnings. Driver performance improved when collision warning information was presented through multiple modalities. Brake response times were significantly faster for impending front-to-rear collision scenarios using the longer headway condition. The presence of mirrors significantly reduced the number of accidents for impending side collision scenarios. Subjective preference data indicated that participants preferred multimodal displays over single-modality displays. Actual or potential applications for this research include auditory displays and warnings, information presentation, and the development of alternative user interfaces.

  17. Synchronization

    Indian Academy of Sciences (India)

    Towards the end some real life exam- ples are also discussed. 1. Introduction. Synchronization, in simple terms, ..... certain relationship between their phases is termed as phase locking. GENERAL I ARTICLE ral frequencies beginning to oscillate at a common fre- quency owing to coupling is called frequency locking or.

  18. Synchronization

    Indian Academy of Sciences (India)

    When a swarm of fireflies gather, they have been found to flash in synchrony. GENERAL I ARTICLE node is due to synchronization of the rhythms of the collection of pacemaker cells. In a pathological case, the pacemaker cells become faulty which results in an abnormally low heart rate known as bradycardia. This results in ...

  19. Small-signal model of a decoupled double synchronous reference frame current controller

    DEFF Research Database (Denmark)

    Dowlatabadi, Mohammadkazem Bakhshizadeh; Hjerrild, Jester; Kocewiak, Lukasz

    2016-01-01

    the dq signals are not dc anymore, and therefore, linearization cannot be done. In this paper a Decoupled Double Synchronous Frame PLL is used to eliminate the oscillations in the dq frame signals. The small signal model of this PLL including an unbalanced current controller is presented in this paper....

  20. Joint Iterative Carrier Synchronization and Signal Detection for Dual Carrier 448 Gb/s PDM 16-QAM

    DEFF Research Database (Denmark)

    Zibar, Darko; Carvalho, Luis; Estaran Tolosa, Jose Manuel

    2013-01-01

    Soft decision driven joint carrier synchronization and signal detection, employing expectation maximization, is experimentally demonstrated. Employing soft decisions offers an improvement of 0.5 dB compared to hard decision digital PLL based carrier synchronization and demodulation....

  1. Controlling hyperchaos and periodic synchronization in DOPO with parameter modulated by an external periodic signal

    Energy Technology Data Exchange (ETDEWEB)

    Feng Xiuqin [Department of Physics, ChangChun University of Science and Technology, ChangChun 130022 (China)], E-mail: Fengxq@cust.edu.cn; Shen Ke [Department of Physics, ChangChun University of Science and Technology, ChangChun 130022 (China)

    2008-02-15

    Hyperchaotic behaviors can be controlled and converted into periodic behaviors by modulating the detuned parameters using an external periodic signal in degenerated optical parameter oscillator (DOPO). Numerical simulations show that the period number differs on the account of the modulating coefficient. Increasing the modulating coefficient, the DOPO results in conversion to periodic orbits. Subsequently it is converted into period 2, and then into period 1. It was also shown that the periodic orbits of the DOPOs modulated through external periodic signal can result in identical synchronization or anti-synchronization only in the case that the largest Lyapunov exponent of the system is negative. Thus synchronization types and evolution process of synchronization is determined by modulating coefficient and initial conditions.

  2. Adaptive synchronization of fractional Lorenz systems using a reduced number of control signals and parameters

    International Nuclear Information System (INIS)

    Aguila-Camacho, Norelys; Duarte-Mermoud, Manuel A.; Delgado-Aguilera, Efredy

    2016-01-01

    This paper analyzes the synchronization of two fractional Lorenz systems in two cases: the first one considering fractional Lorenz systems with unknown parameters, and the second one considering known upper bounds on some of the fractional Lorenz systems parameters. The proposed control strategies use a reduced number of control signals and control parameters, employing mild assumptions. The stability of the synchronization errors is analytically demonstrated in all cases, and the convergence to zero of the synchronization errors is analytically proved in the case when the upper bounds on some system parameters are assumed to be known. Simulation studies are presented, which allows verifying the effectiveness of the proposed control strategies.

  3. Remote Synchronization Experiments for Quasi-Zenith Satellite System Using Multiple Navigation Signals as Feedback Control

    Directory of Open Access Journals (Sweden)

    Toshiaki Iwata

    2011-01-01

    Full Text Available The remote synchronization system for the onboard crystal oscillator (RESSOX is a remote control method that permits synchronization between a ground station atomic clock and Japanese quasi-zenith satellite system (QZSS crystal oscillators. To realize the RESSOX of the QZSS, the utilization of navigation signals of QZSS for feedback control is an important issue. Since QZSS transmits seven navigation signals (L1C/A, L1CP, L1CD, L2CM, L2CL, L5Q, and L5I, all combinations of these signals should be evaluated. First, the RESSOX algorithm will be introduced. Next, experimental performance will be demonstrated. If only a single signal is available, ionospheric delay should be input from external measurements. If multiple frequency signals are available, any combination, except for L2 and L5, gives good performance with synchronization error being within two nanoseconds that of RESSOX. The combination of L1CD and L5Q gives the best synchronization performance (synchronization error within 1.14 ns. Finally, in the discussion, comparisons of long-duration performance, computer simulation, and sampling number used in feedback control are considered. Although experimental results do not correspond to the simulation results, the tendencies are similar. For the overlapping Allan deviation of long duration, the stability of 1.23×10−14 at 100,160 s is obtained.

  4. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Directory of Open Access Journals (Sweden)

    Xiaojian Hu

    2015-01-01

    Full Text Available Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN. Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

  5. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Science.gov (United States)

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN. PMID:25663835

  6. The influence of signal type on the internal auditory representation of a room

    Science.gov (United States)

    Teret, Elizabeth

    Currently, architectural acousticians make no real distinction between a room impulse response and the auditory system's internal representation of a room. With this lack of a good model for the auditory representation of a room, it is indirectly assumed that our internal representation of a room is independent of the sound source needed to make the room characteristics audible. The extent to which this assumption holds true is examined with perceptual tests. Listeners are presented with various pairs of signals (music, speech, and noise) convolved with synthesized impulse responses of different reverberation times. They are asked to adjust the reverberation of one of the signals to match the other. Analysis of the data show that the source signal significantly influences perceived reverberance. Listeners are less accurate when matching reverberation times of varied signals than they are with identical signals. Additional testing shows that perception of reverberation can be linked to the existence of transients in the signal.

  7. Diagnostics of synchronous motor based on analysis of acoustic signals with application of MFCC and Nearest Mean classifier

    OpenAIRE

    Adam Głowacz; Witold Głowacz; Andrzej Głowacz

    2010-01-01

    The paper presents method of diagnostics of imminent failure conditions of synchronous motor. This method is based on a study ofacoustic signals generated by synchronous motor. Sound recognition system is based on algorithms of data processing, such as MFCC andNearest Mean classifier with cosine distance. Software to recognize the sounds of synchronous motor was implemented. The studies werecarried out for four imminent failure conditions of synchronous motor. The results confirm that the sys...

  8. Method and apparatus for a single channel digital communications system. [synchronization of received PCM signal by digital correlation with reference signal

    Science.gov (United States)

    Couvillon, L. A., Jr.; Carl, C.; Goldstein, R. M.; Posner, E. C.; Green, R. R. (Inventor)

    1973-01-01

    A method and apparatus are described for synchronizing a received PCM communications signal without requiring a separate synchronizing channel. The technique provides digital correlation of the received signal with a reference signal, first with its unmodulated subcarrier and then with a bit sync code modulated subcarrier, where the code sequence length is equal in duration to each data bit.

  9. Developmental changes of BOLD signal correlations with global human EEG power and synchronization during working memory.

    Directory of Open Access Journals (Sweden)

    Lars Michels

    Full Text Available In humans, theta band (5-7 Hz power typically increases when performing cognitively demanding working memory (WM tasks, and simultaneous EEG-fMRI recordings have revealed an inverse relationship between theta power and the BOLD (blood oxygen level dependent signal in the default mode network during WM. However, synchronization also plays a fundamental role in cognitive processing, and the level of theta and higher frequency band synchronization is modulated during WM. Yet, little is known about the link between BOLD, EEG power, and EEG synchronization during WM, and how these measures develop with human brain maturation or relate to behavioral changes. We examined EEG-BOLD signal correlations from 18 young adults and 15 school-aged children for age-dependent effects during a load-modulated Sternberg WM task. Frontal load (in-dependent EEG theta power was significantly enhanced in children compared to adults, while adults showed stronger fMRI load effects. Children demonstrated a stronger negative correlation between global theta power and the BOLD signal in the default mode network relative to adults. Therefore, we conclude that theta power mediates the suppression of a task-irrelevant network. We further conclude that children suppress this network even more than adults, probably from an increased level of task-preparedness to compensate for not fully mature cognitive functions, reflected in lower response accuracy and increased reaction time. In contrast to power, correlations between instantaneous theta global field synchronization and the BOLD signal were exclusively positive in both age groups but only significant in adults in the frontal-parietal and posterior cingulate cortices. Furthermore, theta synchronization was weaker in children and was--in contrast to EEG power--positively correlated with response accuracy in both age groups. In summary we conclude that theta EEG-BOLD signal correlations differ between spectral power and

  10. Signal Transmission of Biological Reaction-Diffusion System by Using Synchronization

    Directory of Open Access Journals (Sweden)

    Lingli Zhou

    2017-10-01

    Full Text Available Molecular signal transmission in cell is very crucial for information exchange. How to understand its transmission mechanism has attracted many researchers. In this paper, we prove that signal transmission problem between neural tumor molecules and drug molecules can be achieved by synchronous control. To achieve our purpose, we derive the Fokker-Plank equation by using the Langevin equation and theory of random walk, this is a model which can express the concentration change of neural tumor molecules. Second, according to the biological character that vesicles in cell can be combined with cell membrane to release the cargo which plays a role of signal transmission, we preliminarily analyzed the mechanism of tumor-drug molecular interaction. Third, we propose the view of synchronous control which means the process of vesicle docking with their target membrane is a synchronization process, and we can achieve the precise treatment of disease by using synchronous control. We believe this synchronous control mechanism is reasonable and two examples are given to illustrate the correctness of our results obtained in this paper.

  11. Fully Photonic Wireless Link for Transmission of Synchronization Signals

    Directory of Open Access Journals (Sweden)

    O. Wilfert

    2016-04-01

    Full Text Available Rapid industrialization and increasing demand of business tools for high-speed communications supports the request for optical communications in free space. Copper cables and related technologies such as cable modems and Digital Subscriber Line (DSL are common in existing networks, but do not meet the bandwidth requirement in the future, which opens the door to optical wireless communication technologies. Research in links for optical wireless communication (Infra Red Line of Sight, IR LOS working in the atmosphere is due to the wide support of its development on the world market. Optical wireless communications research is currently focused on increasing the transmission quality of data links. A promising new trend in data connection through IR LOS includes the transfer of accurate time synchronization pulses (time transmission. The article presents problems of modeling and design of a transmitter and receiver with a fully photonic concept. The analysis of the power levels at the link and drawn a model for determining the connection losses at the receiver caused by optical coupling between a Schmidt-Cassegrain telescope and the receiving optical fiber is shown.

  12. Auditory signal processing in communication: perception and performance of vocal sounds.

    Science.gov (United States)

    Prather, Jonathan F

    2013-11-01

    Learning and maintaining the sounds we use in vocal communication require accurate perception of the sounds we hear performed by others and feedback-dependent imitation of those sounds to produce our own vocalizations. Understanding how the central nervous system integrates auditory and vocal-motor information to enable communication is a fundamental goal of systems neuroscience, and insights into the mechanisms of those processes will profoundly enhance clinical therapies for communication disorders. Gaining the high-resolution insight necessary to define the circuits and cellular mechanisms underlying human vocal communication is presently impractical. Songbirds are the best animal model of human speech, and this review highlights recent insights into the neural basis of auditory perception and feedback-dependent imitation in those animals. Neural correlates of song perception are present in auditory areas, and those correlates are preserved in the auditory responses of downstream neurons that are also active when the bird sings. Initial tests indicate that singing-related activity in those downstream neurons is associated with vocal-motor performance as opposed to the bird simply hearing itself sing. Therefore, action potentials related to auditory perception and action potentials related to vocal performance are co-localized in individual neurons. Conceptual models of song learning involve comparison of vocal commands and the associated auditory feedback to compute an error signal that is used to guide refinement of subsequent song performances, yet the sites of that comparison remain unknown. Convergence of sensory and motor activity onto individual neurons points to a possible mechanism through which auditory and vocal-motor signals may be linked to enable learning and maintenance of the sounds used in vocal communication. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives". Copyright © 2013

  13. Sensitivity of offset and onset cortical auditory evoked potentials to signals in noise.

    Science.gov (United States)

    Baltzell, Lucas S; Billings, Curtis J

    2014-02-01

    The purpose of this study was to determine the effects of SNR and signal level on the offset response of the cortical auditory evoked potential (CAEP). Successful listening often depends on how well the auditory system can extract target signals from competing background noise. Both signal onsets and offsets are encoded neurally and contribute to successful listening in noise. Neural onset responses to signals in noise demonstrate a strong sensitivity to signal-to-noise ratio (SNR) rather than signal level; however, the sensitivity of neural offset responses to these cues is not known. We analyzed the offset response from two previously published datasets for which only the onset response was reported. For both datasets, CAEPs were recorded from young normal-hearing adults in response to a 1000-Hz tone. For the first dataset, tones were presented at seven different signal levels without background noise, while the second dataset varied both signal level and SNR. Offset responses demonstrated sensitivity to absolute signal level in quiet, SNR, and to absolute signal level in noise. Offset sensitivity to signal level when presented in noise contrasts with previously published onset results. This sensitivity suggests a potential clinical measure of cortical encoding of signal level in noise.

  14. Fast synchronization of ultradian oscillators controlled by delta-notch signaling with cis-inhibition.

    Directory of Open Access Journals (Sweden)

    Hendrik B Tiedemann

    2014-10-01

    Full Text Available While it is known that a large fraction of vertebrate genes are under the control of a gene regulatory network (GRN forming a clock with circadian periodicity, shorter period oscillatory genes like the Hairy-enhancer-of split (Hes genes are discussed mostly in connection with the embryonic process of somitogenesis. They form the core of the somitogenesis-clock, which orchestrates the periodic separation of somites from the presomitic mesoderm (PSM. The formation of sharp boundaries between the blocks of many cells works only when the oscillators in the cells forming the boundary are synchronized. It has been shown experimentally that Delta-Notch (D/N signaling is responsible for this synchronization. This process has to happen rather fast as a cell experiences at most five oscillations from its 'birth' to its incorporation into a somite. Computer simulations describing synchronized oscillators with classical modes of D/N-interaction have difficulties to achieve synchronization in an appropriate time. One approach to solving this problem of modeling fast synchronization in the PSM was the consideration of cell movements. Here we show that fast synchronization of Hes-type oscillators can be achieved without cell movements by including D/N cis-inhibition, wherein the mutual interaction of DELTA and NOTCH in the same cell leads to a titration of ligand against receptor so that only one sort of molecule prevails. Consequently, the symmetry between sender and receiver is partially broken and one cell becomes preferentially sender or receiver at a given moment, which leads to faster entrainment of oscillators. Although not yet confirmed by experiment, the proposed mechanism of enhanced synchronization of mesenchymal cells in the PSM would be a new distinct developmental mechanism employing D/N cis-inhibition. Consequently, the way in which Delta-Notch signaling was modeled so far should be carefully reconsidered.

  15. Fast synchronization of ultradian oscillators controlled by delta-notch signaling with cis-inhibition.

    Science.gov (United States)

    Tiedemann, Hendrik B; Schneltzer, Elida; Zeiser, Stefan; Wurst, Wolfgang; Beckers, Johannes; Przemeck, Gerhard K H; Hrabě de Angelis, Martin

    2014-10-01

    While it is known that a large fraction of vertebrate genes are under the control of a gene regulatory network (GRN) forming a clock with circadian periodicity, shorter period oscillatory genes like the Hairy-enhancer-of split (Hes) genes are discussed mostly in connection with the embryonic process of somitogenesis. They form the core of the somitogenesis-clock, which orchestrates the periodic separation of somites from the presomitic mesoderm (PSM). The formation of sharp boundaries between the blocks of many cells works only when the oscillators in the cells forming the boundary are synchronized. It has been shown experimentally that Delta-Notch (D/N) signaling is responsible for this synchronization. This process has to happen rather fast as a cell experiences at most five oscillations from its 'birth' to its incorporation into a somite. Computer simulations describing synchronized oscillators with classical modes of D/N-interaction have difficulties to achieve synchronization in an appropriate time. One approach to solving this problem of modeling fast synchronization in the PSM was the consideration of cell movements. Here we show that fast synchronization of Hes-type oscillators can be achieved without cell movements by including D/N cis-inhibition, wherein the mutual interaction of DELTA and NOTCH in the same cell leads to a titration of ligand against receptor so that only one sort of molecule prevails. Consequently, the symmetry between sender and receiver is partially broken and one cell becomes preferentially sender or receiver at a given moment, which leads to faster entrainment of oscillators. Although not yet confirmed by experiment, the proposed mechanism of enhanced synchronization of mesenchymal cells in the PSM would be a new distinct developmental mechanism employing D/N cis-inhibition. Consequently, the way in which Delta-Notch signaling was modeled so far should be carefully reconsidered.

  16. Generation of synchronized signal and pump pulses for an optical ...

    Indian Academy of Sciences (India)

    30%T beam, with an average power of 80 mW, with pulse duration of 650 ps, is reflected by a pickup mirror. This signal beam with 1 nJ energy will be amplified in various OPA stages for making the multi-terawatt laser system. The reflected laser pulses (180 mW power) that are redirected into the pulse stretcher are allowed ...

  17. Simulating GPS radio signal to synchronize network--a new technique for redundant timing.

    Science.gov (United States)

    Shan, Qingxiao; Jun, Yang; Le Floch, Jean-Michel; Fan, Yaohui; Ivanov, Eugene N; Tobar, Michael E

    2014-07-01

    Currently, many distributed systems such as 3G mobile communications and power systems are time synchronized with a Global Positioning System (GPS) signal. If there is a GPS failure, it is difficult to realize redundant timing, and thus time-synchronized devices may fail. In this work, we develop time transfer by simulating GPS signals, which promises no extra modification to original GPS-synchronized devices. This is achieved by applying a simplified GPS simulator for synchronization purposes only. Navigation data are calculated based on a pre-assigned time at a fixed position. Pseudo-range data which describes the distance change between the space vehicle (SV) and users are calculated. Because real-time simulation requires heavy-duty computations, we use self-developed software optimized on a PC to generate data, and save the data onto memory disks while the simulator is operating. The radio signal generation is similar to the SV at an initial position, and the frequency synthesis of the simulator is locked to a pre-assigned time. A filtering group technique is used to simulate the signal transmission delay corresponding to the SV displacement. Each SV generates a digital baseband signal, where a unique identifying code is added to the signal and up-converted to generate the output radio signal at the centered frequency of 1575.42 MHz (L1 band). A prototype with a field-programmable gate array (FPGA) has been built and experiments have been conducted to prove that we can realize time transfer. The prototype has been applied to the CDMA network for a three-month long experiment. Its precision has been verified and can meet the requirements of most telecommunication systems.

  18. Detection of auditory signals in quiet and noisy backgrounds while performing a visuo-spatial task

    Directory of Open Access Journals (Sweden)

    Vishakha W Rawool

    2016-01-01

    Full Text Available Context: The ability to detect important auditory signals while performing visual tasks may be further compounded by background chatter. Thus, it is important to know how task performance may interact with background chatter to hinder signal detection. Aim: To examine any interactive effects of speech spectrum noise and task performance on the ability to detect signals. Settings and Design: The setting was a sound-treated booth. A repeated measures design was used. Materials and Methods: Auditory thresholds of 20 normal adults were determined at 0.5, 1, 2 and 4 kHz in the following conditions presented in a random order: (1 quiet with attention; (2 quiet with a visuo-spatial task or puzzle (distraction; (3 noise with attention and (4 noise with task. Statistical Analysis: Multivariate analyses of variance (MANOVA with three repeated factors (quiet versus noise, visuo-spatial task versus no task, signal frequency. Results: MANOVA revealed significant main effects for noise and signal frequency and significant noise–frequency and task–frequency interactions. Distraction caused by performing the task worsened the thresholds for tones presented at the beginning of the experiment and had no effect on tones presented in the middle. At the end of the experiment, thresholds (4 kHz were better while performing the task than those obtained without performing the task. These effects were similar across the quiet and noise conditions. Conclusion: Detection of auditory signals is difficult at the beginning of a distracting visuo-spatial task but over time, task learning and auditory training effects can nullify the effect of distraction and may improve detection of high frequency sounds.

  19. Temporally selective processing of communication signals by auditory midbrain neurons

    DEFF Research Database (Denmark)

    Elliott, Taffeta M; Christensen-Dalsgaard, Jakob; Kelley, Darcy B

    2011-01-01

    Perception of the temporal structure of acoustic signals contributes critically to vocal signaling. In the aquatic clawed frog Xenopus laevis, calls differ primarily in the temporal parameter of click rate, which conveys sexual identity and reproductive state. We show here that an ensemble...... click rates ranged from 4 to 50 Hz, the rate at which the clicks begin to overlap. Frequency selectivity and temporal processing were characterized using response-intensity curves, temporal-discharge patterns, and autocorrelations of reduplicated responses to click trains. Characteristic frequencies...

  20. Study of Intelligent Photovoltaic System Fault Diagnostic Scheme Based on Chaotic Signal Synchronization

    Directory of Open Access Journals (Sweden)

    Chin-Tsung Hsieh

    2013-01-01

    Full Text Available As the photovoltaic system consists of many equipment components, manual inspection will be very costly. This study proposes the photovoltaic system fault diagnosis based on chaotic signal synchronization. First, MATLAB was used to simulate the fault conditions of solar system, and the maximum power point tracking (MPPT was used to ensure the system's stable power and capture and record the system fault feature signals. The dynamic errors of various fault signals were extracted by chaotic signal synchronization, and the dynamic error data of various fault signals were recorded completely. In the photovoltaic system, the captured output voltage signal was used as the characteristic values for fault recognition, and the extension theory was used to create the joint domain and classical domain of various fault conditions according to the collected feature data. The matter-element model of extension engineering was constructed. Finally, the whole fault diagnosis system is only needed to capture the voltage signal of the solar photovoltaic system, so as to know the exact fault condition effectively and rapidly. The proposed fault diagnostor can be implemented by embedded system and be combined with ZigBee wireless network module in the future, thus reducing labor cost and building a complete portable renewable energy system fault diagnostor.

  1. Data-derived symbol synchronization of MASK and QASK signals. [Multilevel and Quadrature Amplitude Shift Keying

    Science.gov (United States)

    Simon, M. K.

    1975-01-01

    Much has been said in the literature regarding the problem of establishing symbol synchronization in binary baseband digital communication systems. By comparison, the literature contains little information relating to the extraction of symbol sync from multilevel baseband data. With the recent interest in multilevel amplitude-shift keying (MASK) and quadrature amplitude-shift keying (QASK) as signaling techniques for multilevel digital communications systems, the problem of providing symbol synchronization in the receivers of such systems becomes paramount. This paper presents a technique for extracting symbol sync from a MASK or QASK signal which has been transmitted over an infinite-bandwidth white Gaussian noise channel. The scheme is essentially a generalization of the data transition tracking loop (DTTL) which has heretofore been used in PSK systems. The performance of the loop is analyzed in terms of its mean-squared symbol sync jitter and its effects on the data detection process in MASK and QASK systems.

  2. Heaviside revisited: Distortionless signal transmission through lossy media with application to precision clock synchronization

    International Nuclear Information System (INIS)

    Flake, Robert H.

    2016-01-01

    A recently discovered non-sinusoidal, non-periodic electrical signal in the form of an exponentially rising pulse achieves distortionless propagation at constant velocity through lossy, passive transmission media. This unique property is derived theoretically in the framework of the telegrapher's equation analyzed by Heaviside and confirmed experimentally in propagation of such a pulse along serially connected sections of telephone cable. The utility of the distortion-free pulse within the field of time-domain reflectometry is demonstrated in precise time-of-flight measurement of the reflected signal, with the prospect of enhancing the accuracy of protocols for synchronization of spatially separated clocks. - Highlights: • Introduction of rising exponential shape as a distortion-resistant wave pulse (SD signal) in electrical propagation through lossy media. • Derivation of distortion-free and constant-velocity properties of the SD signal based on telegrapher's equation of Oliver Heaviside. • Experimental demonstration of enhanced precision of time-of-flight measurements utilizing SD signals in the e-TDR. • Design of a precision clock-synchronization procedure based on SD signaling and e-TDR.

  3. Diagnostics of synchronous motor based on analysis of acoustic signals with application of MFCC and Nearest Mean classifier

    Directory of Open Access Journals (Sweden)

    Adam Głowacz

    2010-07-01

    Full Text Available The paper presents method of diagnostics of imminent failure conditions of synchronous motor. This method is based on a study ofacoustic signals generated by synchronous motor. Sound recognition system is based on algorithms of data processing, such as MFCC andNearest Mean classifier with cosine distance. Software to recognize the sounds of synchronous motor was implemented. The studies werecarried out for four imminent failure conditions of synchronous motor. The results confirm that the system can be useful for detectingdamage and protect the engines.

  4. Data-derived symbol synchronization of MASK and QASK signals. [for multilevel digital communication systems

    Science.gov (United States)

    Simon, M. K.

    1974-01-01

    Multilevel amplitude-shift-keying (MASK) and quadrature amplitude-shift-keying (QASK) as signaling techniques for multilevel digital communications systems, and the problem of providing symbol synchronization in the receivers of such systems are discussed. A technique is presented for extracting symbol sync from an MASK or QASK signal. The scheme is a generalization of the data transition tracking loop used in PSK systems. The performance of the loop was analyzed in terms of its mean-squared jitter and its effects on the data detection process in MASK and QASK systems.

  5. An Overview of a Class of Clock Synchronization Algorithms for Wireless Sensor Networks: A Statistical Signal Processing Perspective

    Directory of Open Access Journals (Sweden)

    Xu Wang

    2015-08-01

    Full Text Available Recently, wireless sensor networks (WSNs have drawn great interest due to their outstanding monitoring and management potential in medical, environmental and industrial applications. Most of the applications that employ WSNs demand all of the sensor nodes to run on a common time scale, a requirement that highlights the importance of clock synchronization. The clock synchronization problem in WSNs is inherently related to parameter estimation. The accuracy of clock synchronization algorithms depends essentially on the statistical properties of the parameter estimation algorithms. Recently, studies dedicated to the estimation of synchronization parameters, such as clock offset and skew, have begun to emerge in the literature. The aim of this article is to provide an overview of the state-of-the-art clock synchronization algorithms for WSNs from a statistical signal processing point of view. This article focuses on describing the key features of the class of clock synchronization algorithms that exploit the traditional two-way message (signal exchange mechanism. Upon introducing the two-way message exchange mechanism, the main clock offset estimation algorithms for pairwise synchronization of sensor nodes are first reviewed, and their performance is compared. The class of fully-distributed clock offset estimation algorithms for network-wide synchronization is then surveyed. The paper concludes with a list of open research problems pertaining to clock synchronization of WSNs.

  6. AUX: a scripting language for auditory signal processing and software packages for psychoacoustic experiments and education.

    Science.gov (United States)

    Kwon, Bomjun J

    2012-06-01

    This article introduces AUX (AUditory syntaX), a scripting syntax specifically designed to describe auditory signals and processing, to the members of the behavioral research community. The syntax is based on descriptive function names and intuitive operators suitable for researchers and students without substantial training in programming, who wish to generate and examine sound signals using a written script. In this article, the essence of AUX is discussed and practical examples of AUX scripts specifying various signals are illustrated. Additionally, two accompanying Windows-based programs and development libraries are described. AUX Viewer is a program that generates, visualizes, and plays sounds specified in AUX. AUX Viewer can also be used for class demonstrations or presentations. Another program, Psycon, allows a wide range of sound signals to be used as stimuli in common psychophysical testing paradigms, such as the adaptive procedure, the method of constant stimuli, and the method of adjustment. AUX Library is also provided, so that researchers can develop their own programs utilizing AUX. The philosophical basis of AUX is to separate signal generation from the user interface needed for experiments. AUX scripts are portable and reusable; they can be shared by other researchers, regardless of differences in actual AUX-based programs, and reused for future experiments. In short, the use of AUX can be potentially beneficial to all members of the research community-both those with programming backgrounds and those without.

  7. The perceived quality of in-vehicle auditory signals: a structural equation modelling approach.

    Science.gov (United States)

    Chi, Chia-Fen; Dewi, Ratna Sari; Surbakti, Yopie Yutama; Hsieh, Dong-Yu

    2017-11-01

    The current study applied Structural Equation Modelling to analyse the relationship among pitch, loudness, tempo and timbre and their relationship with perceived sound quality. Twenty-eight auditory signals of horn, indicator, door open warning and parking sensor were collected from 11 car brands. Twenty-one experienced drivers were recruited to evaluate all sound signals with 11 semantic differential scales. The results indicate that for the continuous sounds, pitch, loudness and timbre each had a direct impact on the perceived quality. Besides the direct impacts, pitch also had an impact on loudness perception. For the intermittent sounds, tempo and timbre each had a direct impact on the perceived quality. These results can help to identify the psychoacoustic attributes affecting the consumers' quality perception and help to design preferable sounds for vehicles. In the end, a design guideline is proposed for the development of auditory signals that adopts the current study's research findings as well as those of other relevant research. Practitioner Summary: This study applied Structural Equation Modelling to analyse the relationship among pitch, loudness, tempo and timbre and their relationship with perceived sound quality. The result can help to identify psychoacoustic attributes affecting the consumers' quality perception and help to design preferable sounds for vehicles.

  8. Sustained Attention in Auditory and Visual Monitoring Tasks: Evaluation of the Administration of a Rest Break or Exogenous Vibrotactile Signals.

    Science.gov (United States)

    Arrabito, G Robert; Ho, Geoffrey; Aghaei, Behzad; Burns, Catherine; Hou, Ming

    2015-12-01

    Performance and mental workload were observed for the administration of a rest break or exogenous vibrotactile signals in auditory and visual monitoring tasks. Sustained attention is mentally demanding. Techniques are required to improve observer performance in vigilance tasks. Participants (N = 150) monitored an auditory or a visual display for changes in signal duration in a 40-min watch. During the watch, participants were administered a rest break or exogenous vibrotactile signals. Detection accuracy was significantly greater in the auditory than in the visual modality. A short rest break restored detection accuracy in both sensory modalities following deterioration in performance. Participants experienced significantly lower mental workload when monitoring auditory than visual signals, and a rest break significantly reduced mental workload in both sensory modalities. Exogenous vibrotactile signals had no beneficial effects on performance, or mental workload. A rest break can restore performance in auditory and visual vigilance tasks. Although sensory differences in vigilance tasks have been studied, this study is the initial effort to investigate the effects of a rest break countermeasure in both auditory and visual vigilance tasks, and it is also the initial effort to explore the effects of the intervention of a rest break on the perceived mental workload of auditory and visual vigilance tasks. Further research is warranted to determine exact characteristics of effective exogenous vibrotactile signals in vigilance tasks. Potential applications of this research include procedures for decreasing the temporal decline in observer performance and the high mental workload imposed by vigilance tasks. © 2015, Her Majesty the Queen in Right of Canada, as represented by the Minister of National Defence.

  9. Joint transfer of time and frequency signals and multi-point synchronization via fiber network

    Science.gov (United States)

    Nan, Cheng; Wei, Chen; Qin, Liu; Dan, Xu; Fei, Yang; You-Zhen, Gui; Hai-Wen, Cai

    2016-01-01

    A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The noises of the fiber links are suppressed and compensated for by a controlled fiber delay line. A method of calibrating and characterizing time is described. The 1PPS is synchronized by feed-forward calibrating the fiber delays precisely. The system is experimentally examined via a 110 km spooled fiber in laboratory. The frequency stabilities of the user end with compensation are 1.8×10-14 at 1 s and 2.0×10-17 at 104 s average time. The calculated uncertainty of time synchronization is 13.1 ps, whereas the direct measurement of the uncertainty is 12 ps. Next, the frequency and 1PPS are transferred via a metropolitan area optical fiber network from one central site to two remote sites with distances of 14 km and 110 km. The frequency stabilities of 14 km link reach 3.0×10-14 averaged in 1 s and 1.4×10-17 in 104 s respectively; and the stabilities of 110 km link are 8.3×10-14 and 1.7×10-17, respectively. The accuracies of synchronization are estimated to be 12.3 ps for the 14 km link and 13.1 ps for the 110 km link, respectively. Project supported by the National Natural Science Foundation of China (Grant No. 61405227).

  10. Brain-generated estradiol drives long-term optimization of auditory coding to enhance the discrimination of communication signals.

    Science.gov (United States)

    Tremere, Liisa A; Pinaud, Raphael

    2011-03-02

    Auditory processing and hearing-related pathologies are heavily influenced by steroid hormones in a variety of vertebrate species, including humans. The hormone estradiol has been recently shown to directly modulate the gain of central auditory neurons, in real time, by controlling the strength of inhibitory transmission via a nongenomic mechanism. The functional relevance of this modulation, however, remains unknown. Here we show that estradiol generated in the songbird homolog of the mammalian auditory association cortex, rapidly enhances the effectiveness of the neural coding of complex, learned acoustic signals in awake zebra finches. Specifically, estradiol increases mutual information rates, coding efficiency, and the neural discrimination of songs. These effects are mediated by estradiol's modulation of both the rate and temporal coding of auditory signals. Interference with the local action or production of estradiol in the auditory forebrain of freely behaving animals disrupts behavioral responses to songs, but not to other behaviorally relevant communication signals. Our findings directly show that estradiol is a key regulator of auditory function in the adult vertebrate brain.

  11. Grid Synchronization with Selective Harmonic Detection Based on Generalized Delayed Signal Superposition

    DEFF Research Database (Denmark)

    Lu, Yong; Xiao, Guochun; Wang, Xiongfei

    2018-01-01

    Grid synchronization has always been an important challenge for grid-connected converters under extremely distorted grid conditions. Moreover, how to quickly and accurately extract multiple required harmonics is also essential for control systems. In this paper, two types of Generalized Delayed...... Signal Superposition (GDSS) operators capable of extracting any arbitrary harmonic component out of an input signal are derived. In order to show the benefits of GDSS operators, a new grid information estimation concept based on multiple GDSS operators (referred to as MGDSS-PLL) is proposed to track...... the fundamental and multiple targeted harmonics under single-phase and three-phase adverse grid conditions. The introduced MGDSS-PLL can be flexibly tuned to extract any harmonic components according to specific requirements within one fundamental period and it also exhibits great robustness to grid disturbances...

  12. Moving on time: brain network for auditory-motor synchronization is modulated by rhythm complexity and musical training.

    Science.gov (United States)

    Chen, Joyce L; Penhune, Virginia B; Zatorre, Robert J

    2008-02-01

    Much is known about the motor system and its role in simple movement execution. However, little is understood about the neural systems underlying auditory-motor integration in the context of musical rhythm, or the enhanced ability of musicians to execute precisely timed sequences. Using functional magnetic resonance imaging, we investigated how performance and neural activity were modulated as musicians and nonmusicians tapped in synchrony with progressively more complex and less metrically structured auditory rhythms. A functionally connected network was implicated in extracting higher-order features of a rhythm's temporal structure, with the dorsal premotor cortex mediating these auditory-motor interactions. In contrast to past studies, musicians recruited the prefrontal cortex to a greater degree than nonmusicians, whereas secondary motor regions were recruited to the same extent. We argue that the superior ability of musicians to deconstruct and organize a rhythm's temporal structure relates to the greater involvement of the prefrontal cortex mediating working memory.

  13. The effect of auditory verbal imagery on signal detection in hallucination-prone individuals.

    Science.gov (United States)

    Moseley, Peter; Smailes, David; Ellison, Amanda; Fernyhough, Charles

    2016-01-01

    Cognitive models have suggested that auditory hallucinations occur when internal mental events, such as inner speech or auditory verbal imagery (AVI), are misattributed to an external source. This has been supported by numerous studies indicating that individuals who experience hallucinations tend to perform in a biased manner on tasks that require them to distinguish self-generated from non-self-generated perceptions. However, these tasks have typically been of limited relevance to inner speech models of hallucinations, because they have not manipulated the AVI that participants used during the task. Here, a new paradigm was employed to investigate the interaction between imagery and perception, in which a healthy, non-clinical sample of participants were instructed to use AVI whilst completing an auditory signal detection task. It was hypothesized that AVI-usage would cause participants to perform in a biased manner, therefore falsely detecting more voices in bursts of noise. In Experiment 1, when cued to generate AVI, highly hallucination-prone participants showed a lower response bias than when performing a standard signal detection task, being more willing to report the presence of a voice in the noise. Participants not prone to hallucinations performed no differently between the two conditions. In Experiment 2, participants were not specifically instructed to use AVI, but retrospectively reported how often they engaged in AVI during the task. Highly hallucination-prone participants who retrospectively reported using imagery showed a lower response bias than did participants with lower proneness who also reported using AVI. Results are discussed in relation to prominent inner speech models of hallucinations. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Neural Processing of Auditory Signals and Modular Neural Control for Sound Tropism of Walking Machines

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    Hubert Roth

    2008-11-01

    Full Text Available The specialized hairs and slit sensillae of spiders (Cupiennius salei can sense the airflow and auditory signals in a low-frequency range. They provide the sensor information for reactive behavior, like e.g. capturing a prey. In analogy, in this paper a setup is described where two microphones and a neural preprocessing system together with a modular neural controller are used to generate a sound tropism of a four-legged walking machine. The neural preprocessing network is acting as a low-pass filter and it is followed by a network which discerns between signals coming from the left or the right. The parameters of these networks are optimized by an evolutionary algorithm. In addition, a simple modular neural controller then generates the desired different walking patterns such that the machine walks straight, then turns towards a switched-on sound source, and then stops near to it.

  15. Development of a Stair-Step Multifrequency Synchronized Excitation Signal for Fast Bioimpedance Spectroscopy

    Science.gov (United States)

    Bian, He; Du, Fangling; Sun, Qiang

    2014-01-01

    Wideband excitation signal with finite prominent harmonic components is desirable for fast bioimpedance spectroscopy (BIS) measurements. This work introduces a simple method to synthesize and realize a type of periodical stair-step multifrequency synchronized (MFS) signal. The Fourier series analysis shows that the p-order MFS signal f(p, t) has constant 81.06% energy distributed equally on its p  2nth primary harmonics. The synthesis principle is described firstly and then two examples of the 4-order and 5-order MFS signals, f(4, t) and f(5, t), are synthesized. The method to implement the MFS waveform based on a field-programmable gate array (FPGA) and a digital to analog converter (DAC) is also presented. Both the number and the frequencies of the expected primary harmonics can be adjusted as needed. An impedance measurement experiment on a RC three-element equivalent model is performed, and results show acceptable precision, which validates the feasibility of the MFS excitation. PMID:24701563

  16. Development of a Stair-Step Multifrequency Synchronized Excitation Signal for Fast Bioimpedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Yuxiang Yang

    2014-01-01

    Full Text Available Wideband excitation signal with finite prominent harmonic components is desirable for fast bioimpedance spectroscopy (BIS measurements. This work introduces a simple method to synthesize and realize a type of periodical stair-step multifrequency synchronized (MFS signal. The Fourier series analysis shows that the p-order MFS signal f(p,t has constant 81.06% energy distributed equally on its p  2nth primary harmonics. The synthesis principle is described firstly and then two examples of the 4-order and 5-order MFS signals, f(4,t and f(5,t, are synthesized. The method to implement the MFS waveform based on a field-programmable gate array (FPGA and a digital to analog converter (DAC is also presented. Both the number and the frequencies of the expected primary harmonics can be adjusted as needed. An impedance measurement experiment on a RC three-element equivalent model is performed, and results show acceptable precision, which validates the feasibility of the MFS excitation.

  17. Analysis of the influence of memory content of auditory stimuli on the memory content of EEG signal.

    Science.gov (United States)

    Namazi, Hamidreza; Khosrowabadi, Reza; Hussaini, Jamal; Habibi, Shaghayegh; Farid, Ali Akhavan; Kulish, Vladimir V

    2016-08-30

    One of the major challenges in brain research is to relate the structural features of the auditory stimulus to structural features of Electroencephalogram (EEG) signal. Memory content is an important feature of EEG signal and accordingly the brain. On the other hand, the memory content can also be considered in case of stimulus. Beside all works done on analysis of the effect of stimuli on human EEG and brain memory, no work discussed about the stimulus memory and also the relationship that may exist between the memory content of stimulus and the memory content of EEG signal. For this purpose we consider the Hurst exponent as the measure of memory. This study reveals the plasticity of human EEG signals in relation to the auditory stimuli. For the first time we demonstrated that the memory content of an EEG signal shifts towards the memory content of the auditory stimulus used. The results of this analysis showed that an auditory stimulus with higher memory content causes a larger increment in the memory content of an EEG signal. For the verification of this result, we benefit from approximate entropy as indicator of time series randomness. The capability, observed in this research, can be further investigated in relation to human memory.

  18. Recurrence of task set-related MEG signal patterns during auditory working memory.

    Science.gov (United States)

    Peters, Benjamin; Bledowski, Christoph; Rieder, Maria; Kaiser, Jochen

    2016-06-01

    Processing of auditory spatial and non-spatial information in working memory has been shown to rely on separate cortical systems. While previous studies have demonstrated differences in spatial versus non-spatial processing from the encoding of to-be-remembered stimuli onwards, here we investigated whether such differences would be detectable already prior to presentation of the sample stimulus. We analyzed broad-band magnetoencephalography data from 15 healthy adults during an auditory working memory paradigm starting with a visual cue indicating the task-relevant stimulus feature for a given trial (lateralization or pitch) and a subsequent 1.5-s pre-encoding phase. This was followed by a sample sound (0.2s), the delay phase (0.8s) and a test stimulus (0.2s) after which participants made a match/non-match decision. Linear discriminant functions were trained to decode task-specific signal patterns throughout the task, and temporal generalization was used to assess whether the neural codes discriminating between the tasks during the pre-encoding phase would recur during later task periods. The spatial versus non-spatial tasks could indeed be discriminated after the onset of the cue onwards, and decoders trained during the pre-encoding phase successfully discriminated the tasks during both sample stimulus encoding and during the delay phase. This demonstrates that task-specific neural codes are established already before the memorandum is presented and that the same patterns are reestablished during stimulus encoding and maintenance. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A Data Hiding Technique to Synchronously Embed Physiological Signals in H.264/AVC Encoded Video for Medicine Healthcare.

    Science.gov (United States)

    Peña, Raul; Ávila, Alfonso; Muñoz, David; Lavariega, Juan

    2015-01-01

    The recognition of clinical manifestations in both video images and physiological-signal waveforms is an important aid to improve the safety and effectiveness in medical care. Physicians can rely on video-waveform (VW) observations to recognize difficult-to-spot signs and symptoms. The VW observations can also reduce the number of false positive incidents and expand the recognition coverage to abnormal health conditions. The synchronization between the video images and the physiological-signal waveforms is fundamental for the successful recognition of the clinical manifestations. The use of conventional equipment to synchronously acquire and display the video-waveform information involves complex tasks such as the video capture/compression, the acquisition/compression of each physiological signal, and the video-waveform synchronization based on timestamps. This paper introduces a data hiding technique capable of both enabling embedding channels and synchronously hiding samples of physiological signals into encoded video sequences. Our data hiding technique offers large data capacity and simplifies the complexity of the video-waveform acquisition and reproduction. The experimental results revealed successful embedding and full restoration of signal's samples. Our results also demonstrated a small distortion in the video objective quality, a small increment in bit-rate, and embedded cost savings of -2.6196% for high and medium motion video sequences.

  20. Data on the effect of conductive hearing loss on auditory and visual cortex activity revealed by intrinsic signal imaging.

    Science.gov (United States)

    Teichert, Manuel; Bolz, Jürgen

    2017-10-01

    This data article provides additional data related to the research article entitled "Simultaneous intrinsic signal imaging of auditory and visual cortex reveals profound effects of acute hearing loss on visual processing" (Teichert and Bolz, 2017) [1]. The primary auditory and visual cortex (A1 and V1) of adult male C57BL/6J mice (P120-P240) were mapped simultaneously using intrinsic signal imaging (Kalatsky and Stryker, 2003) [2]. A1 and V1 activity evoked by combined auditory and visual stimulation were measured before and after conductive hearing loss (CHL) induced by bilateral malleus removal. We provide data showing that A1 responsiveness evoked by sounds of different sound pressure levels (SPL) decreased after CHL whereas visually evoked V1 activity increased after this intervention. In addition, we also provide imaging data on percentage of V1 activity increases after CHL compared to pre-CHL.

  1. Influence of different envelope maskers on signal recognition and neuronal representation in the auditory system of a grasshopper.

    Directory of Open Access Journals (Sweden)

    Daniela Neuhofer

    Full Text Available BACKGROUND: Animals that communicate by sound face the problem that the signals arriving at the receiver often are degraded and masked by noise. Frequency filters in the receiver's auditory system may improve the signal-to-noise ratio (SNR by excluding parts of the spectrum which are not occupied by the species-specific signals. This solution, however, is hardly amenable to species that produce broad band signals or have ears with broad frequency tuning. In mammals auditory filters exist that work in the temporal domain of amplitude modulations (AM. Do insects also use this type of filtering? PRINCIPAL FINDINGS: Combining behavioural and neurophysiological experiments we investigated whether AM filters may improve the recognition of masked communication signals in grasshoppers. The AM pattern of the sound, its envelope, is crucial for signal recognition in these animals. We degraded the species-specific song by adding random fluctuations to its envelope. Six noise bands were used that differed in their overlap with the spectral content of the song envelope. If AM filters contribute to reduced masking, signal recognition should depend on the degree of overlap between the song envelope spectrum and the noise spectra. Contrary to this prediction, the resistance against signal degradation was the same for five of six masker bands. Most remarkably, the band with the strongest frequency overlap to the natural song envelope (0-100 Hz impaired acceptance of degraded signals the least. To assess the noise filter capacities of single auditory neurons, the changes of spike trains as a function of the masking level were assessed. Increasing levels of signal degradation in different frequency bands led to similar changes in the spike trains in most neurones. CONCLUSIONS: There is no indication that auditory neurones of grasshoppers are specialized to improve the SNR with respect to the pattern of amplitude modulations.

  2. Remote Synchronization Simulation of Onboard Crystal Oscillator for QZSS Using L1/L2/L5 Signals for Error Adjustment

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    Toshiaki Iwata

    2008-01-01

    Full Text Available A new error adjustment method for remote synchronization of the onboard crystal oscillator for the quasi-zenith satellite system (QZSS using three different frequency positioning signals (L1/L2/L5 is proposed. The error adjustment method that uses L1/L2 positioning signals was demonstrated in the past. In both methods, the frequency-dependent part and the frequency-independent part were considered separately, and the total time information delay was estimated. By adopting L1/L2/L5, synchronization was improved by approximately 15% compared with that using L1/L2 and approximately 10% compared with that using L1/L5 and a synchronization error of less than 0.77 nanosecond was realized.

  3. The Role of Head Movements and Signal Spectrum in an Auditory Front/Back Illusion

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    W Owen Brimijoin

    2012-04-01

    Full Text Available We used a dynamic auditory spatial illusion to investigate the role of self-motion and acoustics in shaping our spatial percept of the environment. Using motion capture, we smoothly moved a sound source around listeners as a function of their own head movements. A lowpass filtered sound behind a listener that moved in the direction it would have moved if it had been located in the front was perceived as statically located in front. The contrariwise effect occurred if the sound was in front but moved as if it were behind. The illusion was strongest for sounds lowpass filtered at 500 Hz and weakened as a function of increasing lowpass cutoff frequency. The signals with the most high frequency energy were often associated with an unstable location percept that flickered from front to back as self-motion cues and spectral cues for location came into conflict with one another.

  4. Auditory-visual integration of emotional signals in a virtual environment for cynophobia.

    Science.gov (United States)

    Taffou, Marine; Chapoulie, Emmanuelle; David, Adrien; Guerchouche, Rachid; Drettakis, George; Viaud-Delmon, Isabelle

    2012-01-01

    Cynophobia (dog phobia) has both visual and auditory relevant components. In order to investigate the efficacy of virtual reality (VR) exposure-based treatment for cynophobia, we studied the efficiency of auditory-visual environments in generating presence and emotion. We conducted an evaluation test with healthy participants sensitive to cynophobia in order to assess the capacity of auditory-visual virtual environments (VE) to generate fear reactions. Our application involves both high fidelity visual stimulation displayed in an immersive space and 3D sound. This specificity enables us to present and spatially manipulate fearful stimuli in the auditory modality, the visual modality and both. Our specific presentation of animated dog stimuli creates an environment that is highly arousing, suggesting that VR is a promising tool for cynophobia treatment and that manipulating auditory-visual integration might provide a way to modulate affect.

  5. Auditory object salience: Human cortical processing of non-biological action sounds and their acoustic signal attributes

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    James W Lewis

    2012-05-01

    Full Text Available Whether viewed or heard, an object in action can be segmented from a background scene based on a number of different sensory cues. In the visual system, salient low-level attributes of an image are processed along parallel hierarchies, and involve intermediate stages, such as the lateral occipital cortices, wherein gross-level object form features are extracted prior to stages that show object specificity (e.g. for faces, buildings, or tools. In the auditory system, though relying on a rather different set of low-level signal attributes, a distinct acoustic event or auditory object can also be readily extracted from a background acoustic scene. However, it remains unclear whether cortical processing strategies used by the auditory system similarly extract gross-level aspects of acoustic object form that may be inherent to many real-world sounds. Examining mechanical and environmental action sounds, representing two distinct categories of non-biological and non-vocalization sounds, we had participants assess the degree to which each sound was perceived as a distinct object versus an acoustic scene. Using two functional magnetic resonance imaging (fMRI task paradigms, we revealed bilateral foci along the superior temporal gyri (STG showing sensitivity to the object-ness ratings of action sounds, independent of the category of sound and independent of task demands. Moreover, for both categories of sounds these regions also showed parametric sensitivity to spectral structure variations—a measure of change in entropy in the acoustic signals over time (acoustic form—while only the environmental sounds showed parametric sensitivity to mean entropy measures. Thus, similar to the visual system, the auditory system appears to include intermediate feature extraction stages that are sensitive to the acoustic form of action sounds, and may serve as a stage that begins to dissociate different categories of real-world auditory objects.

  6. To modulate and be modulated: estrogenic influences on auditory processing of communication signals within a socio-neuro-endocrine framework.

    Science.gov (United States)

    Yoder, Kathleen M; Vicario, David S

    2012-02-01

    Gonadal hormones modulate behavioral responses to sexual stimuli, and communication signals can also modulate circulating hormone levels. In several species, these combined effects appear to underlie a two-way interaction between circulating gonadal hormones and behavioral responses to socially salient stimuli. Recent work in songbirds has shown that manipulating local estradiol levels in the auditory forebrain produces physiological changes that affect discrimination of conspecific vocalizations and can affect behavior. These studies provide new evidence that estrogens can directly alter auditory processing and indirectly alter the behavioral response to a stimulus. These studies show that: 1) Local estradiol action within an auditory area is necessary for socially relevant sounds to induce normal physiological responses in the brains of both sexes; 2) These physiological effects occur much more quickly than predicted by the classical time-frame for genomic effects; 3) Estradiol action within the auditory forebrain enables behavioral discrimination among socially relevant sounds in males; and 4) Estradiol is produced locally in the male brain during exposure to particular social interactions. The accumulating evidence suggests a socio-neuro-endocrinology framework in which estradiol is essential to auditory processing, is increased by a socially relevant stimulus, acts rapidly to shape perception of subsequent stimuli experienced during social interactions, and modulates behavioral responses to these stimuli. Brain estrogens are likely to function similarly in both songbird sexes because aromatase and estrogen receptors are present in both male and female forebrain. Estrogenic modulation of perception in songbirds and perhaps other animals could fine-tune male advertising signals and female ability to discriminate them, facilitating mate selection by modulating behaviors.

  7. Application of «Sensor signal analysis network» complex for distributed, time synchronized analysis of electromagnetic radiation

    Science.gov (United States)

    Mochalov, Vladimir; Mochalova, Anastasia

    2017-10-01

    The paper considers a developing software-hardware complex «Sensor signal analysis network» for distributed and time synchronized analysis of electromagnetic radiations. The areas of application and the main features of the complex are described. An example of application of the complex to monitor natural electromagnetic radiation sources is considered based on the data recorded in VLF range. A generalized functional scheme of stream analysis of signals by a complex functional node is suggested and its application for stream detection of atmospherics, whistlers and tweaks is considered.

  8. Application of «Sensor signal analysis network» complex for distributed, time synchronized analysis of electromagnetic radiation

    Directory of Open Access Journals (Sweden)

    Mochalov Vladimir

    2017-01-01

    Full Text Available The paper considers a developing software-hardware complex «Sensor signal analysis network» for distributed and time synchronized analysis of electromagnetic radiations. The areas of application and the main features of the complex are described. An example of application of the complex to monitor natural electromagnetic radiation sources is considered based on the data recorded in VLF range. A generalized functional scheme of stream analysis of signals by a complex functional node is suggested and its application for stream detection of atmospherics, whistlers and tweaks is considered.

  9. Robust Frame Synchronization for Low Signal-to-Noise Ratio Channels Using Energy-Corrected Differential Correlation

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    Kim Pansoo

    2009-01-01

    Full Text Available Recent standards for wireless transmission require reliable synchronization for channels with low signal-to-noise ratio (SNR as well as with a large amount of frequency offset, which necessitates a robust correlator structure for the initial frame synchronization process. In this paper, a new correlation strategy especially targeted for low SNR regions is proposed and its performance is analyzed. By utilizing a modified energy correction term, the proposed method effectively reduces the variance of the decision variable to enhance the detection performance. Most importantly, the method is demonstrated to outperform all previously reported schemes by a significant margin, for SNRs below 5 dB regardless of the existence of the frequency offsets. A variation of the proposed method is also presented for further enhancement over the channels with small frequency errors. The particular application considered for the performance verification is the second generation digital video broadcasting system for satellites (DVB-S2.

  10. Validation of a raw data-based synchronization signal (kymogram) for phase-correlated cardiac image reconstruction

    International Nuclear Information System (INIS)

    Ertel, Dirk; Kachelriess, Marc; Kalender, Willi A.; Pflederer, Tobias; Achenbach, Stephan; Steffen, Peter

    2008-01-01

    Phase-correlated reconstruction is commonly used in computed tomography (CT)-based cardiac imaging. Alternatively to the commonly used ECG, the raw data-based kymogram function can be used as a synchronization signal. We used raw data of 100 consecutive patient exams to compare the performance of kymogram function to the ECG signal. For objective validation the correlation of the ECG and the kymogram was assessed. Additionally, we performed a double-blinded comparison of ECG-based and kymogram-based phase-correlated images. The two synchronization signals showed good correlation indicated by a mean difference in the detected heart rate of negligible 0.2 bpm. The mean image quality score was 2.0 points for kymogram-correlated images and 2.3 points for ECG-correlated images, respectively (3: best; 0: worst). The kymogram and the ECG provided images adequate for diagnosis for 93 and 97 patients, respectively. For 50% of the datasets the kymogram provided an equivalent or even higher image quality compared with the ECG signal. We conclude that an acceptable image quality can be assured in most cases by the kymogram. Improvements of image quality by the kymogram function were observed in a noticeable number of cases. The kymogram can serve as a backup solution when an ECG is not available or lacking in quality. (orig.)

  11. An all digital phase locked loop for synchronization of a sinusoidal signal embedded in white Gaussian noise

    Science.gov (United States)

    Reddy, C. P.; Gupta, S. C.

    1973-01-01

    An all digital phase locked loop which tracks the phase of the incoming sinusoidal signal once per carrier cycle is proposed. The different elements and their functions and the phase lock operation are explained in detail. The nonlinear difference equations which govern the operation of the digital loop when the incoming signal is embedded in white Gaussian noise are derived, and a suitable model is specified. The performance of the digital loop is considered for the synchronization of a sinusoidal signal. For this, the noise term is suitably modelled which allows specification of the output probabilities for the two level quantizer in the loop at any given phase error. The loop filter considered increases the probability of proper phase correction. The phase error states in modulo two-pi forms a finite state Markov chain which enables the calculation of steady state probabilities, RMS phase error, transient response and mean time for cycle skipping.

  12. Pattern of BOLD signal in auditory cortex relates acoustic response to perceptual streaming

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    Yadav Deepak

    2011-08-01

    Full Text Available Abstract Background Segregating auditory scenes into distinct objects or streams is one of our brain's greatest perceptual challenges. Streaming has classically been studied with bistable sound stimuli, perceived alternately as a single group or two separate groups. Throughout the last decade different methodologies have yielded inconsistent evidence about the role of auditory cortex in the maintenance of streams. In particular, studies using functional magnetic resonance imaging (fMRI have been unable to show persistent activity within auditory cortex (AC that distinguishes between perceptual states. Results We use bistable stimuli, an explicit perceptual categorization task, and a focused region of interest (ROI analysis to demonstrate an effect of perceptual state within AC. We find that AC has more activity when listeners perceive the split percept rather than the grouped percept. In addition, within this ROI the pattern of acoustic response across voxels is significantly correlated with the pattern of perceptual modulation. In a whole-brain exploratory test, we corroborate previous work showing an effect of perceptual state in the intraparietal sulcus. Conclusions Our results show that the maintenance of auditory streams is reflected in AC activity, directly relating sound responses to perception, and that perceptual state is further represented in multiple, higher level cortical regions.

  13. Second-Order Optimal Array Receivers for Synchronization of BPSK, MSK, and GMSK Signals Corrupted by Noncircular Interferences

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    François Delaveau

    2007-01-01

    Full Text Available The synchronization and/or time acquisition problem in the presence of interferences has been strongly studied these last two decades, mainly to mitigate the multiple access interferences from other users in DS/CDMA systems. Among the available receivers, only some scarce receivers may also be used in other contexts such as F/TDMA systems. However, these receivers assume implicitly or explicitly circular (or proper interferences and become suboptimal for noncircular (or improper interferences. Such interferences are characteristic in particular of radio communication networks using either rectilinear (or monodimensional modulations such as BPSK modulation or modulation becoming quasirectilinear after a preprocessing such as MSK, GMSK, or OQAM modulations. For this reason, the purpose of this paper is to introduce and to analyze the performance of second-optimal array receivers for synchronization and/or time acquisition of BPSK, MSK, and GMSK signals corrupted by noncircular interferences. For given performances and in the presence of rectilinear signal and interferences, the proposed receiver allows a reduction of the number of sensors by a factor at least equal to two.

  14. On the impact index of synchronous generator displaced by DFIG on power system small-signal stability

    Science.gov (United States)

    Bi, J. T.; Du, W. J.; Wang, H. F.; Song, Y. T.; Wang, Q.; Ding, J.; Chen, D. Z.; Wei, W.

    2017-05-01

    As the maturity of wind power technology and the ageing and retirement of conventional synchronous generators, the displacement of synchronous generators by wind power generators would be a trend in the next few decades. The power system small-signal angular stability caused by the displacement is an urgent problem to be studied. The displacement of the SG by the DFIG includes withdrawing the dynamic interactions of the displaced SG and adding the dynamic interactions of the displacing DFIG. Based on this fact, a new index is proposed to predict the impact of the SG to be displaced by the DFIG on power system oscillation modes. The sensitivity index of the oscillation modes to the constant inertia of the displaced SGs, proposed in early literatures to estimate the dynamic impact of the SG being displaced by the DFIG, is also compared with the proposed index. The modified New England power system is adopted to show various results and conclusions. The proposed index can correctly identify the most dangerous and beneficial displacement to power system small-signal angular stability, and is very useful in practical applications.

  15. Combinatorial Modulation of Signaling Pathways Reveals Cell-Type-Specific Requirements for Highly Efficient and Synchronous iPSC Reprogramming

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    Simon E. Vidal

    2014-10-01

    Full Text Available The differentiated state of somatic cells provides barriers for the derivation of induced pluripotent stem cells (iPSCs. To address why some cell types reprogram more readily than others, we studied the effect of combined modulation of cellular signaling pathways. Surprisingly, inhibition of transforming growth factor β (TGF-β together with activation of Wnt signaling in the presence of ascorbic acid allows >80% of murine fibroblasts to acquire pluripotency after 1 week of reprogramming factor expression. In contrast, hepatic and blood progenitors predominantly required only TGF-β inhibition or canonical Wnt activation, respectively, to reprogram at efficiencies approaching 100%. Strikingly, blood progenitors reactivated endogenous pluripotency loci in a highly synchronous manner, and we demonstrate that expression of specific chromatin-modifying enzymes and reduced TGF-β/mitogen-activated protein (MAP kinase activity are intrinsic properties associated with the unique reprogramming response of these cells. Our observations define cell-type-specific requirements for the rapid and synchronous reprogramming of somatic cells.

  16. [The role of the ventral nucleus of the lateral lemniscus in sound signal processing and auditory ascending transmission].

    Science.gov (United States)

    Liu, Hui-Hua; Luo, Feng; Wang, Xin

    2014-06-25

    The ventral nucleus of the lateral lemniscus (VNLL) is an important nucleus in the central auditory pathway which connects the lower brainstem and the midbrain inferior colliculus (IC). Previous studies have demonstrated that neurons in the VNLL could respond to sound signal parameters. Frequency tuning curves (FTCs) of VNLL neurons are generally wider than FTCs of IC neurons, suggesting that the VNLL does not enhance abilities of frequency discrimination and coding. Two types of rate-intensity functions (RIFs) are found in the VNLL: monotonic and non-monotonic RIFs. Intensity-tuning of VNLL neurons are affected by the temporal firing patterns during processing and encoding intensity. There are multiple temporal firing patterns in VNLL neurons. Onset pattern has a precise timing characteristic which is well suited to encode temporal features of stimuli, and also very important to animal behavior including bat's echolocation. The VNLL accepts inputs from lower nuclei, uploads glycine inhibitory outputs to IC, and modulates response characteristics generating and acoustic signal processing of IC neurons. Recent research suggests that fast inhibitory projection from the VNLL may delay the first spike latency of IC neurons, and the delayed inhibitory projection from the VNLL may mediate the temporal firing patterns of IC neurons. But how inhibitory inputs from the VNLL integrate in IC, and how inhibitory inputs from the VNLL enhance the ability of detecting sound signal of IC neurons are not very clear and need more direct evidence at the level of neurons. These questions will help further understand the role of upload during IC processes acoustic signal, which are our research target in the future. This article reviews the current literature regarding the roles of the VNLL in sound signal processing and the auditory ascending transmission, including advances in the relevant research in our laboratory.

  17. An Association between Auditory-Visual Synchrony Processing and Reading Comprehension: Behavioral and Electrophysiological Evidence.

    Science.gov (United States)

    Mossbridge, Julia; Zweig, Jacob; Grabowecky, Marcia; Suzuki, Satoru

    2017-03-01

    The perceptual system integrates synchronized auditory-visual signals in part to promote individuation of objects in cluttered environments. The processing of auditory-visual synchrony may more generally contribute to cognition by synchronizing internally generated multimodal signals. Reading is a prime example because the ability to synchronize internal phonological and/or lexical processing with visual orthographic processing may facilitate encoding of words and meanings. Consistent with this possibility, developmental and clinical research has suggested a link between reading performance and the ability to compare visual spatial/temporal patterns with auditory temporal patterns. Here, we provide converging behavioral and electrophysiological evidence suggesting that greater behavioral ability to judge auditory-visual synchrony (Experiment 1) and greater sensitivity of an electrophysiological marker of auditory-visual synchrony processing (Experiment 2) both predict superior reading comprehension performance, accounting for 16% and 25% of the variance, respectively. These results support the idea that the mechanisms that detect auditory-visual synchrony contribute to reading comprehension.

  18. Experiment on Synchronous Timing Signal Detection from ISDB-T Terrestrial Digital TV Signal with Application to Autonomous Distributed ITS-IVC Network

    Science.gov (United States)

    Karasawa, Yoshio; Kumagai, Taichi; Takemoto, Atsushi; Fujii, Takeo; Ito, Kenji; Suzuki, Noriyoshi

    A novel timing synchronizing scheme is proposed for use in inter-vehicle communication (IVC) with an autonomous distributed intelligent transport system (ITS). The scheme determines the timing of packet signal transmission in the IVC network and employs the guard interval (GI) timing in the orthogonal frequency divisional multiplexing (OFDM) signal currently used for terrestrial broadcasts in the Japanese digital television system (ISDB-T). This signal is used because it is expected that the automotive market will demand the capability for cars to receive terrestrial digital TV broadcasts in the near future. The use of broadcasts by automobiles presupposes that the on-board receivers are capable of accurately detecting the GI timing data in an extremely low carrier-to-noise ratio (CNR) condition regardless of a severe multipath environment which will introduce broad scatter in signal arrival times. Therefore, we analyzed actual broadcast signals received in a moving vehicle in a field experiment and showed that the GI timing signal is detected with the desired accuracy even in the case of extremely low-CNR environments. Some considerations were also given about how to use these findings.

  19. Fresh Prime Codes Evaluation for Synchronous PPM and OPPM Signaling for Optical CDMA Networks

    Science.gov (United States)

    Karbassian, M. Massoud; Ghafouri-Shiraz, H.

    2007-06-01

    In this paper, we have proposed a novel prime spreading sequence family hereby referred to as “Double-Padded Modified Prime Code (DPMPC)” for direct-detection synchronous optical code-division multiple-access (OCDMA) networks. The new code is applied to both pulse-position and overlapping pulse-position modulation CDMA networks, and their performances were evaluated and compared with existing prime codes family. In addition, we have analyzed the system throughput and also introduced a new interference cancellation technique which significantly improves the bit error probability of OCDMA networks.

  20. Auditory object salience: human cortical processing of non-biological action sounds and their acoustic signal attributes.

    Science.gov (United States)

    Lewis, James W; Talkington, William J; Tallaksen, Katherine C; Frum, Chris A

    2012-01-01

    Whether viewed or heard, an object in action can be segmented as a distinct salient event based on a number of different sensory cues. In the visual system, several low-level attributes of an image are processed along parallel hierarchies, involving intermediate stages wherein gross-level object form and/or motion features are extracted prior to stages that show greater specificity for different object categories (e.g., people, buildings, or tools). In the auditory system, though relying on a rather different set of low-level signal attributes, meaningful real-world acoustic events and "auditory objects" can also be readily distinguished from background scenes. However, the nature of the acoustic signal attributes or gross-level perceptual features that may be explicitly processed along intermediate cortical processing stages remain poorly understood. Examining mechanical and environmental action sounds, representing two distinct non-biological categories of action sources, we had participants assess the degree to which each sound was perceived as object-like versus scene-like. We re-analyzed data from two of our earlier functional magnetic resonance imaging (fMRI) task paradigms (Engel et al., 2009) and found that scene-like action sounds preferentially led to activation along several midline cortical structures, but with strong dependence on listening task demands. In contrast, bilateral foci along the superior temporal gyri (STG) showed parametrically increasing activation to action sounds rated as more "object-like," independent of sound category or task demands. Moreover, these STG regions also showed parametric sensitivity to spectral structure variations (SSVs) of the action sounds-a quantitative measure of change in entropy of the acoustic signals over time-and the right STG additionally showed parametric sensitivity to measures of mean entropy and harmonic content of the environmental sounds. Analogous to the visual system, intermediate stages of the

  1. Auditory object salience: human cortical processing of non-biological action sounds and their acoustic signal attributes

    Science.gov (United States)

    Lewis, James W.; Talkington, William J.; Tallaksen, Katherine C.; Frum, Chris A.

    2012-01-01

    Whether viewed or heard, an object in action can be segmented as a distinct salient event based on a number of different sensory cues. In the visual system, several low-level attributes of an image are processed along parallel hierarchies, involving intermediate stages wherein gross-level object form and/or motion features are extracted prior to stages that show greater specificity for different object categories (e.g., people, buildings, or tools). In the auditory system, though relying on a rather different set of low-level signal attributes, meaningful real-world acoustic events and “auditory objects” can also be readily distinguished from background scenes. However, the nature of the acoustic signal attributes or gross-level perceptual features that may be explicitly processed along intermediate cortical processing stages remain poorly understood. Examining mechanical and environmental action sounds, representing two distinct non-biological categories of action sources, we had participants assess the degree to which each sound was perceived as object-like versus scene-like. We re-analyzed data from two of our earlier functional magnetic resonance imaging (fMRI) task paradigms (Engel et al., 2009) and found that scene-like action sounds preferentially led to activation along several midline cortical structures, but with strong dependence on listening task demands. In contrast, bilateral foci along the superior temporal gyri (STG) showed parametrically increasing activation to action sounds rated as more “object-like,” independent of sound category or task demands. Moreover, these STG regions also showed parametric sensitivity to spectral structure variations (SSVs) of the action sounds—a quantitative measure of change in entropy of the acoustic signals over time—and the right STG additionally showed parametric sensitivity to measures of mean entropy and harmonic content of the environmental sounds. Analogous to the visual system, intermediate stages

  2. Perceptual consequences of disrupted auditory nerve activity.

    Science.gov (United States)

    Zeng, Fan-Gang; Kong, Ying-Yee; Michalewski, Henry J; Starr, Arnold

    2005-06-01

    Perceptual consequences of disrupted auditory nerve activity were systematically studied in 21 subjects who had been clinically diagnosed with auditory neuropathy (AN), a recently defined disorder characterized by normal outer hair cell function but disrupted auditory nerve function. Neurological and electrophysical evidence suggests that disrupted auditory nerve activity is due to desynchronized or reduced neural activity or both. Psychophysical measures showed that the disrupted neural activity has minimal effects on intensity-related perception, such as loudness discrimination, pitch discrimination at high frequencies, and sound localization using interaural level differences. In contrast, the disrupted neural activity significantly impairs timing related perception, such as pitch discrimination at low frequencies, temporal integration, gap detection, temporal modulation detection, backward and forward masking, signal detection in noise, binaural beats, and sound localization using interaural time differences. These perceptual consequences are the opposite of what is typically observed in cochlear-impaired subjects who have impaired intensity perception but relatively normal temporal processing after taking their impaired intensity perception into account. These differences in perceptual consequences between auditory neuropathy and cochlear damage suggest the use of different neural codes in auditory perception: a suboptimal spike count code for intensity processing, a synchronized spike code for temporal processing, and a duplex code for frequency processing. We also proposed two underlying physiological models based on desynchronized and reduced discharge in the auditory nerve to successfully account for the observed neurological and behavioral data. These methods and measures cannot differentiate between these two AN models, but future studies using electric stimulation of the auditory nerve via a cochlear implant might. These results not only show the unique

  3. Stable Operation and Small-Signal Analysis of Multiple Parallel DG Inverters Based on a Virtual Synchronous Generator Scheme

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2018-01-01

    Full Text Available For a high penetration level of distributed energy resources (DERs in the grid, virtual synchronous generator (VSG control is applied to the power electronic converters to mimic the rotating mass and damping property of a conventional synchronous generator (SG, which can support virtual inertia and damping for the power system. For VSG control, a phase locked loop (PLL is needed to estimate the angular frequency of the point of common coupling (PCC; however, the deviation of PLL will affect the accuracy of the active power reference, and even the VSG stability control. From this perspective, an enhanced active power controller without PLL was proposed for VSG control. Furthermore, an accurate small-signal model of the multiple parallel VSGs system that considers the dynamic characteristics and the changing of a steady state operation point was derived for system analysis and parameter design. Based on this model, the influence rules of the eigenvalues by droop and virtual inertia were acquired. The simulation and experimental results are presented to verify the validity of the proposed active power controller and parameter design rules.

  4. Optical Synchronization of a 10-G Ethernet Packet and Time-Division Multiplexing to a 50-Gb/s Signal Using an Optical Time Lens

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Palushani, Evarist

    2010-01-01

    A 10-G Ethernet packet with maximum packet size of 1518 bytes is synchronized to a master clock with 200-kHz frequency offset using a time lens. The input 10-Gb/s non-return-to-zero packet is at the same time converted into a return-to-zero (RZ) packet with a pulsewidth of 10 ps and then time......-division multiplexed with four 10-Gb/s optical time-division-multiplexing (OTDM) channels, thus constituting a 50-Gb/s OTDM serial signal. Error-free performances of the synchronized RZ packet and demultiplexed packet from the aggregated 50-Gb/s OTDM signal are achieved....

  5. Synchronizing microelectrode and electronic goniometer data using a pseudo-random binary signal.

    Science.gov (United States)

    Moore, Tyler Robert; Jacobs, Rennie Underwood; Yang, Alexander Cheung; Richter, Erich Oscar

    2013-04-01

    Intra-operative investigation of the subthalamic nucleus (STN) requires concurrent measurement of microelectrode voltage, electrode depth and joint movement during deep brain stimulation (DBS) surgery. Commercial solutions to this problem exist but are more expensive. Multiple instruments from different manufacturers can collect the same data, but data from incompatible instruments are collected on disparate clocks, precluding quantitative analysis. A pseudo-random binary signal recorded simultaneously by each set of instruments allows for chronological reconciliation. A custom program collects microelectrode data while simultaneously sending a pseudo-random binary signal to instruments measuring joint movement. The record of this signal is later used to express microelectrode voltage and joint position in a single chronological frame of reference. ClockSynch was used in 15 DBS procedures. After each surgery, records of microelectrode and joint movement were successfully chronologically reconciled. In conclusion, a pseudo-random binary signal integrates disparate systems of instrumentation at a significantly decreased cost.

  6. Selective attention and the auditory vertex potential. 2: Effects of signal intensity and masking noise

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1975-01-01

    A randomized sequence of tone bursts was delivered to subjects at short inter-stimulus intervals with the tones originating from one of three spatially and frequency specific channels. The subject's task was to count the tones in one of the three channels at a time, ignoring the other two, and press a button after each tenth tone. In different conditions, tones were given at high and low intensities and with or without a background white noise to mask the tones. The N sub 1 component of the auditory vertex potential was found to be larger in response to attended channel tones in relation to unattended tones. This selective enhancement of N sub 1 was minimal for loud tones presented without noise and increased markedly for the lower tone intensity and in noise added conditions.

  7. Synchronicity from Synchronized Chaos

    Directory of Open Access Journals (Sweden)

    Gregory S. Duane

    2015-03-01

    Full Text Available The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related eventsmysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1 synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2 the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable interpretations if the quantum world resides on a generalized synchronization “manifold”.

  8. Power law scaling in synchronization of brain signals depends on cognitive load.

    Science.gov (United States)

    Tinker, Jesse; Velazquez, Jose Luis Perez

    2014-01-01

    As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task). There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa), which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviors.

  9. Power law scaling in synchronization of brain signals depends on cognitive load

    Directory of Open Access Journals (Sweden)

    Jose Luis ePerez Velazquez

    2014-05-01

    Full Text Available As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task. There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa, which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviours.

  10. Visual and Auditory Synchronization Deficits Among Dyslexic Readers as Compared to Non-impaired Readers: A Cross-Correlation Algorithm Analysis

    Directory of Open Access Journals (Sweden)

    Itamar eSela

    2014-06-01

    Full Text Available Visual and auditory temporal processing and crossmodal integration are crucial factors in the word decoding process. The speed of processing gap (Asynchrony between these two modalities, which has been suggested as related to the dyslexia phenomenon, is the focus of the current study. Nineteen dyslexic and 17 non-impaired University adult readers were given stimuli in a reaction time procedure where participants were asked to identify whhether the stimulus type was only visual, only auditory or crossmodally integrated. Accuracy, reaction time, and Event Related Potential (ERP measures were obtained for each of the three conditions. An algorithm to measure the contribution of the temporal speed of processing of each modality to the crossmodal integration in each group of participants was developed. Results obtained using this model for the analysis of the current study data, indicated that in the crossmodal integration condition the presence of the auditory modality at the pre-response time frame (between 170- 240 ms after stimulus presentation, increased processing speed in the visual modality among the non-impaired readers, but not in the dyslexic group. The differences between the temporal speed of processing of the modalities among the dyslexics and the non-impaired readers give additional support to the theory that an asynchrony between the visual and auditory modalities is a cause of dyslexia.

  11. Effects of Sleep Deprivation on Phase Synchronization as Assessed by Wavelet Phase Coherence Analysis of Prefrontal Tissue Oxyhemoglobin Signals.

    Science.gov (United States)

    Bu, Lingguo; Zhang, Ming; Li, Jianfeng; Li, Fangyi; Liu, Heshan; Li, Zengyong

    2017-01-01

    To reveal the physiological mechanism of the decline in cognitive function after sleep deprivation, a within-subject study was performed to assess sleep deprivation effects on phase synchronization, as revealed by wavelet phase coherence (WPCO) analysis of prefrontal tissue oxyhemoglobin signals. Twenty subjects (10 male and 10 female, 25.5 ± 3.5 years old) were recruited to participate in two tests: one without sleep deprivation (group A) and the other with 24 h of sleep deprivation (group B). Before the test, each subject underwent a subjective evaluation using visual analog scales. A cognitive task was performed by judging three random numbers. Continuous recordings of the near-infrared spectroscopy (NIRS) signals were obtained from both the left and right prefrontal lobes during rest, task, and post-task periods. The WPCO of cerebral Delta [HbO2] signals were analyzed for these three periods for both groups A and B. Six frequency intervals were defined: I: 0.6-2 Hz (cardiac activity), II: 0.145-0.6 Hz (respiratory activity), III: 0.052-0.145 Hz (myogenic activity), IV: 0.021-0.052 Hz (neurogenic activity), V: 0.0095-0.021 Hz (nitric oxide related endothelial activity) and VI: 0.005-0.0095 Hz (non-nitric oxide related endothelial activity). WPCO in intervals III (F = 5.955, p = 0.02) and V (F = 4.7, p = 0.037) was significantly lower in group B than in group A at rest. During the task period, WPCO in intervals III (F = 5.175, p = 0.029) and IV (F = 4.585, p = 0.039) was significantly lower in group B compared with group A. In the post-task recovery period, the WPCO in interval III (F = 6.125, p = 0.02) was significantly lower in group B compared with group A. Reaction time was significantly prolonged, and the accuracy rate and F1 score both declined after sleep deprivation. The decline in WPCO after sleep deprivation indicates reduced phase synchronization between left and right prefrontal oxyhemoglobin oscillations, which may contribute to the diminished

  12. An interprojection sensor fusion approach to estimate blocked projection signal in synchronized moving grid-based CBCT system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong; Kong, Vic [Department of Radiation Oncology, Georgia Regents University, Augusta, Georgia 30912 (United States); Ren, Lei; Giles, William; Zhang, You [Department of Radiation Oncology, Duke University, Durham, North Carolina 27710 (United States); Jin, Jian-Yue, E-mail: jjin@gru.edu [Department of Radiation Oncology, Georgia Regents University, Augusta, Georgia 30912 and Department of Radiology, Georgia Regents University, Augusta, Georgia 30912 (United States)

    2016-01-15

    Purpose: A preobject grid can reduce and correct scatter in cone beam computed tomography (CBCT). However, half of the signal in each projection is blocked by the grid. A synchronized moving grid (SMOG) has been proposed to acquire two complimentary projections at each gantry position and merge them into one complete projection. That approach, however, suffers from increased scanning time and the technical difficulty of accurately merging the two projections per gantry angle. Herein, the authors present a new SMOG approach which acquires a single projection per gantry angle, with complimentary grid patterns for any two adjacent projections, and use an interprojection sensor fusion (IPSF) technique to estimate the blocked signal in each projection. The method may have the additional benefit of reduced imaging dose due to the grid blocking half of the incident radiation. Methods: The IPSF considers multiple paired observations from two adjacent gantry angles as approximations of the blocked signal and uses a weighted least square regression of these observations to finally determine the blocked signal. The method was first tested with a simulated SMOG on a head phantom. The signal to noise ratio (SNR), which represents the difference of the recovered CBCT image to the original image without the SMOG, was used to evaluate the ability of the IPSF in recovering the missing signal. The IPSF approach was then tested using a Catphan phantom on a prototype SMOG assembly installed in a bench top CBCT system. Results: In the simulated SMOG experiment, the SNRs were increased from 15.1 and 12.7 dB to 35.6 and 28.9 dB comparing with a conventional interpolation method (inpainting method) for a projection and the reconstructed 3D image, respectively, suggesting that IPSF successfully recovered most of blocked signal. In the prototype SMOG experiment, the authors have successfully reconstructed a CBCT image using the IPSF-SMOG approach. The detailed geometric features in the

  13. An interprojection sensor fusion approach to estimate blocked projection signal in synchronized moving grid-based CBCT system

    International Nuclear Information System (INIS)

    Zhang, Hong; Kong, Vic; Ren, Lei; Giles, William; Zhang, You; Jin, Jian-Yue

    2016-01-01

    Purpose: A preobject grid can reduce and correct scatter in cone beam computed tomography (CBCT). However, half of the signal in each projection is blocked by the grid. A synchronized moving grid (SMOG) has been proposed to acquire two complimentary projections at each gantry position and merge them into one complete projection. That approach, however, suffers from increased scanning time and the technical difficulty of accurately merging the two projections per gantry angle. Herein, the authors present a new SMOG approach which acquires a single projection per gantry angle, with complimentary grid patterns for any two adjacent projections, and use an interprojection sensor fusion (IPSF) technique to estimate the blocked signal in each projection. The method may have the additional benefit of reduced imaging dose due to the grid blocking half of the incident radiation. Methods: The IPSF considers multiple paired observations from two adjacent gantry angles as approximations of the blocked signal and uses a weighted least square regression of these observations to finally determine the blocked signal. The method was first tested with a simulated SMOG on a head phantom. The signal to noise ratio (SNR), which represents the difference of the recovered CBCT image to the original image without the SMOG, was used to evaluate the ability of the IPSF in recovering the missing signal. The IPSF approach was then tested using a Catphan phantom on a prototype SMOG assembly installed in a bench top CBCT system. Results: In the simulated SMOG experiment, the SNRs were increased from 15.1 and 12.7 dB to 35.6 and 28.9 dB comparing with a conventional interpolation method (inpainting method) for a projection and the reconstructed 3D image, respectively, suggesting that IPSF successfully recovered most of blocked signal. In the prototype SMOG experiment, the authors have successfully reconstructed a CBCT image using the IPSF-SMOG approach. The detailed geometric features in the

  14. Effects of lengthening the speech signal on auditory word discrimination in kindergartners with SLI

    NARCIS (Netherlands)

    Segers, P.C.J.; Verhoeven, L.T.W.

    2005-01-01

    In the present study, it was investigated whether kindergartners with specific language impairment (SLI) and normallanguage achieving (NLA) kindergartners can benefit from slowing down the entire speech signal or part of the speech signal in a synthetic speech discrimination task. Subjects were 19

  15. Phase synchronization for classification of spontaneous EEG signals in brain-computer interfaces

    OpenAIRE

    Gysels, Elly; Kunt, Murat; Celka, Patrick

    2007-01-01

    By directly analyzing brain activity, Brain-Computer Interfaces (BCIs) allow for communication that does not rely on any muscular control and therefore constitute a possible communication channel for the completely paralyzed. Typically, the user performs different mental tasks, that correspond to different output commands as recognized by the system. From the recorded brain signals (Electroencephalogram, EEG), features that characterize the mental tasks and allow their discrimination by a cla...

  16. Phase synchronization for classification of spontaneous EEG signals in brain-computer interfaces

    OpenAIRE

    Gysels, Elly

    2005-01-01

    By directly analyzing brain activity, Brain-Computer Interfaces (BCIs) allow for communication that does not rely on any muscular control and therefore constitute a possible communication channel for the completely paralyzed. Typically, the user performs different mental tasks, that correspond to different output commands as recognized by the system. From the recorded brain signals (Electroencephalogram, EEG), features that characterize the mental tasks and allow their discrimination by a cla...

  17. The new analytical expression for measurement uncertainty in a measuring of RMS value of AC signals as result of non ideal synchronization

    Directory of Open Access Journals (Sweden)

    Petrović Predrag

    2006-01-01

    Full Text Available Synchronous sampling allows alternating current (AC quantities, such as the root mean square (RMS values of voltage and power, to be determined with very low uncertainties (on the order of a few parts of 10-6 [1]. In this a new mathematical expression for estimating measurement uncertainties in non ideal synchronization with fundamental frequency AC signals is presented. The obtained results were compared with those obtained with a high-precision instrument for measuring basic AC values. Computer simulation demonstrating the effectiveness of these new expression, are also presented.

  18. The Mere Co-Presence: Synchronization of Autonomic Signals and Emotional Responses across Co-Present Individuals Not Engaged in Direct Interaction

    Science.gov (United States)

    Golland, Yulia; Arzouan, Yossi; Levit-Binnun, Nava

    2015-01-01

    Existing evidence suggests that in social contexts individuals become coupled in their emotions and behaviors. Furthermore, recent biological studies demonstrate that the physiological signals of interacting individuals become coupled as well, exhibiting temporally synchronized response patterns. However, it is yet unknown whether people can shape each other's responses without the direct, face-to-face interaction. Here we investigated whether the convergence of physiological and emotional states can occur among “merely co-present” individuals, without direct interactional exchanges. To this end, we measured continuous autonomic signals and collected emotional responses of participants who watched emotional movies together, seated side-by-side. We found that the autonomic signals of co-present participants were idiosyncratically synchronized and that the degree of this synchronization was correlated with the convergence of their emotional responses. These findings suggest that moment-to-moment emotional transmissions, resulting in shared emotional experiences, can occur in the absence of direct communication and are mediated by autonomic synchronization. PMID:26018597

  19. Simvastatin protects auditory hair cells from gentamicin-induced toxicity and activates Akt signaling in vitro

    Directory of Open Access Journals (Sweden)

    Brand Yves

    2011-11-01

    Full Text Available Abstract Background Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, known as statins, are commonly used as cholesterol-lowering drugs. During the past decade, evidence has emerged that statins also have neuroprotective effects. Research in the retina has shown that simvastatin, a commonly used statin, increases Akt phosphorylation in vivo, indicating that the PI3K/Akt pathway contributes to the protective effects achieved. While research about neuroprotective effects have been conducted in several systems, the effects of statins on the inner ear are largely unknown. Results We evaluated whether the 3-hydroxy-3-methylglutaryl-coenzyme A reductase is present within the rat cochlea and whether simvastatin is able to protect auditory hair cells from gentamicin-induced apoptotic cell death in a in vitro mouse model. Furthermore, we evaluated whether simvastatin increases Akt phosphorylation in the organ of Corti. We detected 3-hydroxy-3-methylglutaryl-coenzyme A reductase mRNA in organ of Corti, spiral ganglion, and stria vascularis by reverse transcriptase-polymerase chain reaction (RT-PCR. Moreover, we observed a dose-dependent and significant reduction of hair cell loss in organs of Corti treated with simvastatin in addition to gentamicin, as compared to samples treated with gentamicin alone. The protective effect of simvastatin was reversed by addition of mevalonate, a downstream metabolite blocked by simvastatin, demonstrating the specificity of protection. Finally, Western blotting showed an increase in organ of Corti Akt phosphorylation after simvastatin treatment in vitro. Conclusion These results suggest a neuroprotective effect of statins in the inner ear, mediated by reduced 3-hydroxy-3-methylglutaryl-coenzyme A reductase metabolism and Akt activation.

  20. Synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Pecora, Louis M.; Carroll, Thomas L.

    2015-01-01

    We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators

  1. Neural processing of auditory signals and modular neural control for sound tropism of walking machines

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Pasemann, Frank; Fischer, Joern

    2005-01-01

    and a neural preprocessing system together with a modular neural controller are used to generate a sound tropism of a four-legged walking machine. The neural preprocessing network is acting as a low-pass filter and it is followed by a network which discerns between signals coming from the left or the right...

  2. Synaptic Plasticity and NO-cGMP-PKG Signaling Coordinately Regulate ERK-Driven Gene Expression in the Lateral Amygdala and in the Auditory Thalamus Following Pavlovian Fear Conditioning

    Science.gov (United States)

    Ota, Kristie T.; Monsey, Melissa S.; Wu, Melissa S.; Young, Grace J.; Schafe, Glenn E.

    2010-01-01

    We have recently hypothesized that NO-cGMP-PKG signaling in the lateral nucleus of the amygdala (LA) during auditory fear conditioning coordinately regulates ERK-driven transcriptional changes in both auditory thalamic (MGm/PIN) and LA neurons that serve to promote pre- and postsynaptic alterations at thalamo-LA synapses, respectively. In the…

  3. Influence of multi-microphone signal enhancement algorithms on auditory movement detection in acoustically complex situations

    DEFF Research Database (Denmark)

    Lundbeck, Micha; Hartog, Laura; Grimm, Giso

    2017-01-01

    The influence of hearing aid (HA) signal processing on the perception of spatially dynamic sounds has not been systematically investigated so far. Previously, we observed that interfering sounds impaired the detectability of left-right source movements and reverberation that of near-far source...... movements for elderly hearing-impaired (EHI) listeners (Lundbeck et al., 2017). Here, we explored potential ways of improving these deficits with HAs. To that end, we carried out acoustic analyses to examine the impact of two beamforming algorithms and a binaural coherence-based noise reduction scheme...... on the cues underlying movement perception. While binaural cues remained mostly unchanged, there were greater monaural spectral changes and increases in signal-to-noise ratio and direct-to-reverberant sound ratio as a result of the applied processing. Based on these findings, we conducted a listening test...

  4. Influence of multi-microphone signal enhancement algorithms on auditory movement detection in acoustically complex situations

    DEFF Research Database (Denmark)

    Lundbeck, Micha; Hartog, Laura; Grimm, Giso

    The influence of hearing aid (HA) signal processing on the perception of spatially dynamic sounds has not been systematically investigated so far. Previously, we observed that for elderly hearing-impaired (EHI) listeners concurrent distractor sounds impaired the detectability of left-right source...... movements, and reverberation that of near-far source movements (Lundbeck et al, Trends Hear 2017). Here, we explored potential ways of improving these deficits with HAs. To that end, we carried out detailed acoustic analyses on the stimuli used previously to examine the impact of two beamforming algorithms...... and a binaural coherence-based noise reduction scheme on the cues underlying movement perception. While the binaural cues remained mostly unchanged, the applied processing led to greater monaural spectral changes, as well as increases in signal-to-noise ratio and direct-to-reverberant sound ratio. Based...

  5. Sensory augmentation: integration of an auditory compass signal into human perception of space.

    Science.gov (United States)

    Schumann, Frank; O'Regan, J Kevin

    2017-02-14

    Bio-mimetic approaches to restoring sensory function show great promise in that they rapidly produce perceptual experience, but have the disadvantage of being invasive. In contrast, sensory substitution approaches are non-invasive, but may lead to cognitive rather than perceptual experience. Here we introduce a new non-invasive approach that leads to fast and truly perceptual experience like bio-mimetic techniques. Instead of building on existing circuits at the neural level as done in bio-mimetics, we piggy-back on sensorimotor contingencies at the stimulus level. We convey head orientation to geomagnetic North, a reliable spatial relation not normally sensed by humans, by mimicking sensorimotor contingencies of distal sounds via head-related transfer functions. We demonstrate rapid and long-lasting integration into the perception of self-rotation. Short training with amplified or reduced rotation gain in the magnetic signal can expand or compress the perceived extent of vestibular self-rotation, even with the magnetic signal absent in the test. We argue that it is the reliability of the magnetic signal that allows vestibular spatial recalibration, and the coding scheme mimicking sensorimotor contingencies of distal sounds that permits fast integration. Hence we propose that contingency-mimetic feedback has great potential for creating sensory augmentation devices that achieve fast and genuinely perceptual experiences.

  6. Auditory adaptation improves tactile frequency perception

    NARCIS (Netherlands)

    Crommett, L.E.; Pérez Bellido, A.; Yau, J.M.

    2017-01-01

    Our ability to process temporal frequency information by touch underlies our capacity to perceive and discriminate surface textures. Auditory signals, which also provide extensive temporal frequency information, can systematically alter the perception of vibrations on the hand. How auditory signals

  7. A method to synchronize signals from multiple patient monitoring devices through a single input channel for inclusion in list-mode acquisitions

    Energy Technology Data Exchange (ETDEWEB)

    O’Connor, J. Michael; Pretorius, P. Hendrik; Johnson, Karen; King, Michael A., E-mail: Michael.King@umassmed.edu [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2013-12-15

    Purpose: This technical note documents a method that the authors developed for combining a signal to synchronize a patient-monitoring device with a second physiological signal for inclusion into list-mode acquisition. Our specific application requires synchronizing an external patient motion-tracking system with a medical imaging system by multiplexing the tracking input with the ECG input. The authors believe that their methodology can be adapted for use in a variety of medical imaging modalities including single photon emission computed tomography (SPECT) and positron emission tomography (PET). Methods: The authors insert a unique pulse sequence into a single physiological input channel. This sequence is then recorded in the list-mode acquisition along with the R-wave pulse used for ECG gating. The specific form of our pulse sequence allows for recognition of the time point being synchronized even when portions of the pulse sequence are lost due to collisions with R-wave pulses. This was achieved by altering our software used in binning the list-mode data to recognize even a portion of our pulse sequence. Limitations on heart rates at which our pulse sequence could be reliably detected were investigated by simulating the mixing of the two signals as a function of heart rate and time point during the cardiac cycle at which our pulse sequence is mixed with the cardiac signal. Results: The authors have successfully achieved accurate temporal synchronization of our motion-tracking system with acquisition of SPECT projections used in 17 recent clinical research cases. In our simulation analysis the authors determined that synchronization to enable compensation for body and respiratory motion could be achieved for heart rates up to 125 beats-per-minute (bpm). Conclusions: Synchronization of list-mode acquisition with external patient monitoring devices such as those employed in motion-tracking can reliably be achieved using a simple method that can be implemented using

  8. Auditory Display

    DEFF Research Database (Denmark)

    volume. The conference's topics include auditory exploration of data via sonification and audification; real time monitoring of multivariate date; sound in immersive interfaces and teleoperation; perceptual issues in auditory display; sound in generalized computer interfaces; technologies supporting...... auditory display creation; data handling for auditory display systems; applications of auditory display....

  9. Development of a Method to Compensate for Signal Quality Variations in Repeated Auditory Event-Related Potential Recordings

    Science.gov (United States)

    Paukkunen, Antti K. O.; Leminen, Miika M.; Sepponen, Raimo

    2010-01-01

    Reliable measurements are mandatory in clinically relevant auditory event-related potential (AERP)-based tools and applications. The comparability of the results gets worse as a result of variations in the remaining measurement error. A potential method is studied that allows optimization of the length of the recording session according to the concurrent quality of the recorded data. In this way, the sufficiency of the trials can be better guaranteed, which enables control of the remaining measurement error. The suggested method is based on monitoring the signal-to-noise ratio (SNR) and remaining measurement error which are compared to predefined threshold values. The SNR test is well defined, but the criterion for the measurement error test still requires further empirical testing in practice. According to the results, the reproducibility of average AERPs in repeated experiments is improved in comparison to a case where the number of recorded trials is constant. The test-retest reliability is not significantly changed on average but the between-subject variation in the value is reduced by 33–35%. The optimization of the number of trials also prevents excessive recordings which might be of practical interest especially in the clinical context. The efficiency of the method may be further increased by implementing online tools that improve data consistency. PMID:20407635

  10. Neural processing of auditory signals and modular neural control for sound tropism of walking machines

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Pasemann, Frank; Fischer, Joern

    2005-01-01

    and a neural preprocessing system together with a modular neural controller are used to generate a sound tropism of a four-legged walking machine. The neural preprocessing network is acting as a low-pass filter and it is followed by a network which discerns between signals coming from the left or the right....... The parameters of these networks are optimized by an evolutionary algorithm. In addition, a simple modular neural controller then generates the desired different walking patterns such that the machine walks straight, then turns towards a switched-on sound source, and then stops near to it....

  11. Vestibular hearing and neural synchronization.

    Science.gov (United States)

    Emami, Seyede Faranak; Daneshi, Ahmad

    2012-01-01

    Objectives. Vestibular hearing as an auditory sensitivity of the saccule in the human ear is revealed by cervical vestibular evoked myogenic potentials (cVEMPs). The range of the vestibular hearing lies in the low frequency. Also, the amplitude of an auditory brainstem response component depends on the amount of synchronized neural activity, and the auditory nerve fibers' responses have the best synchronization with the low frequency. Thus, the aim of this study was to investigate correlation between vestibular hearing using cVEMPs and neural synchronization via slow wave Auditory Brainstem Responses (sABR). Study Design. This case-control survey was consisted of twenty-two dizzy patients, compared to twenty healthy controls. Methods. Intervention comprised of Pure Tone Audiometry (PTA), Impedance acoustic metry (IA), Videonystagmography (VNG), fast wave ABR (fABR), sABR, and cVEMPs. Results. The affected ears of the dizzy patients had the abnormal findings of cVEMPs (insecure vestibular hearing) and the abnormal findings of sABR (decreased neural synchronization). Comparison of the cVEMPs at affected ears versus unaffected ears and the normal persons revealed significant differences (P < 0.05). Conclusion. Safe vestibular hearing was effective in the improvement of the neural synchronization.

  12. Small-signal stability analysis of DC-link voltage control system affected by synchronization control in a wind turbine connected to weak grid

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yunhui; Yuan, Xiaoming; Hu, Jiabing [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Laboratory of Advanced Electromagnetic Engineering and Technology

    2012-07-01

    In this paper, small-signal stability of DC-link voltage control loop, affected by PLL which is also called synchronization control, is researched under weak grid condition. Similar to small-signal stability analysis of the traditional power system, a small-signal model of the grid-connected converter is presented. This model includes DC-link voltage control loop and PLL. It is analyzed in physics that how synchronization control affects small-signal stability of DC-link voltage control system. Influencing factors of small signal stability of DC-link voltage control system is presented and analyzed including DC-link voltage controller parameter, PLL controller parameter, strength of grid and operating point. An improved control strategy is proposed to enhance the small-signal stability of DC-link voltage control system. Simulations on a 1.5-MW full-capacity wind power generation system are conducted in Matlab/Simulink and the feasibility of the proposed control scheme is validated. (orig.)

  13. Subcortical modulation in auditory processing and auditory hallucinations.

    Science.gov (United States)

    Ikuta, Toshikazu; DeRosse, Pamela; Argyelan, Miklos; Karlsgodt, Katherine H; Kingsley, Peter B; Szeszko, Philip R; Malhotra, Anil K

    2015-12-15

    Hearing perception in individuals with auditory hallucinations has not been well studied. Auditory hallucinations have previously been shown to involve primary auditory cortex activation. This activation suggests that auditory hallucinations activate the terminal of the auditory pathway as if auditory signals are submitted from the cochlea, and that a hallucinatory event is therefore perceived as hearing. The primary auditory cortex is stimulated by some unknown source that is outside of the auditory pathway. The current study aimed to assess the outcomes of stimulating the primary auditory cortex through the auditory pathway in individuals who have experienced auditory hallucinations. Sixteen patients with schizophrenia underwent functional magnetic resonance imaging (fMRI) sessions, as well as hallucination assessments. During the fMRI session, auditory stimuli were presented in one-second intervals at times when scanner noise was absent. Participants listened to auditory stimuli of sine waves (SW) (4-5.5kHz), English words (EW), and acoustically reversed English words (arEW) in a block design fashion. The arEW were employed to deliver the sound of a human voice with minimal linguistic components. Patients' auditory hallucination severity was assessed by the auditory hallucination item of the Brief Psychiatric Rating Scale (BPRS). During perception of arEW when compared with perception of SW, bilateral activation of the globus pallidus correlated with severity of auditory hallucinations. EW when compared with arEW did not correlate with auditory hallucination severity. Our findings suggest that the sensitivity of the globus pallidus to the human voice is associated with the severity of auditory hallucination. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Top-down signal transmission and global hyperconnectivity in auditory-visual synesthesia: Evidence from a functional EEG resting-state study.

    Science.gov (United States)

    Brauchli, Christian; Elmer, Stefan; Rogenmoser, Lars; Burkhard, Anja; Jäncke, Lutz

    2018-01-01

    Auditory-visual (AV) synesthesia is a rare phenomenon in which an auditory stimulus induces a "concurrent" color sensation. Current neurophysiological models of synesthesia mainly hypothesize "hyperconnected" and "hyperactivated" brains, but differ in the directionality of signal transmission. The two-stage model proposes bottom-up signal transmission from inducer- to concurrent- to higher-order brain areas, whereas the disinhibited feedback model postulates top-down signal transmission from inducer- to higher-order- to concurrent brain areas. To test the different models of synesthesia, we estimated local current density, directed and undirected connectivity patterns in the intracranial space during 2 min of resting-state (RS) EEG in 11 AV synesthetes and 11 nonsynesthetes. AV synesthetes demonstrated increased parietal theta, alpha, and lower beta current density compared to nonsynesthetes. Furthermore, AV synesthetes were characterized by increased top-down signal transmission from the superior parietal lobe to the left color processing area V4 in the upper beta frequency band. Analyses of undirected connectivity revealed a global, synesthesia-specific hyperconnectivity in the alpha frequency band. The involvement of the superior parietal lobe even during rest is a strong indicator for its key role in AV synesthesia. By demonstrating top-down signal transmission in AV synesthetes, we provide direct support for the disinhibited feedback model of synesthesia. Finally, we suggest that synesthesia is a consequence of global hyperconnectivity. Hum Brain Mapp 39:522-531, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  15. Division Multiplexing of 10 Gbit/s Ethernet Signals Synchronized by All-Optical Signal Processing Based on a Time-Lens

    DEFF Research Database (Denmark)

    Areal, Janaina Laguardia

    This Thesis presents 3 years work of an optical circuit that performs both pulse compression and frame synchronization and retiming. Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This scheme is optically trans-parent and does...... pulse compression, as well. The over-all design is: (1) Pulses are converted from NRZ to RZ; (2) pulses are synchronized, retimed and further compressed at the specially de-signed time-lens; and (3) with adequate optical delays, frames from different input interfaces are added, with a simple optical...

  16. Optical Time-Division Multiplexing of 10 Gbit/s Ethernet Signals Synchronized by All-Optical Signal Processing Based on a Time-Lens

    DEFF Research Database (Denmark)

    Areal, Janaina Laguardia

    This Thesis presents 3 years work of an optical circuit that performs both pulse compression and frame synchronization and retiming. Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This scheme is optically transparent and does...... pulse compression, as well. The overall design is: (1) Pulses are converted from NRZ to RZ; (2) pulses are synchronized, retimed and further compressed at the specially designed time-lens; and (3) with adequate optical delays, frames from different input interfaces are added, with a simple optical...

  17. High-sweeping-speed optically synchronized dual-channel terahertz-signal generator for driving a superconducting tunneling mixer and its application to active gas sensing.

    Science.gov (United States)

    Oh, Kyoung-Hwan; Shimizu, Naofumi; Kohjiro, Satoshi; Kikuchi, Ken'ichi; Wakatsuki, Atsushi; Kukutsu, Naoya; Kado, Yuichi

    2009-10-12

    We propose a high-sweeping-speed optically synchronized dual-channel terahertz (THz) signal generator for an active gas-sensing system with a superconductor-insulator-superconductor (SIS) mixer. The generator can sweep a frequency range from 200 to 500 GHz at a speed of 375 GHz/s and a frequency resolution of 500 MHz. With the developed gas-sensing system, a gas-absorption-line measurement was successfully carried out with N(2)O gas in that frequency range.

  18. Meaning From Environmental Sounds: Types of Signal-Referent Relations and Their Effect on Recognizing Auditory Icons

    Science.gov (United States)

    Keller, Peter; Stevens, Catherine

    2004-01-01

    This article addresses the learnability of auditory icons, that is, environmental sounds that refer either directly or indirectly to meaningful events. Direct relations use the sound made by the target event whereas indirect relations substitute a surrogate for the target. Across 3 experiments, different indirect relations (ecological, in which…

  19. Differential sensory cortical involvement in auditory and visual sensorimotor temporal recalibration: Evidence from transcranial direct current stimulation (tDCS).

    Science.gov (United States)

    Aytemür, Ali; Almeida, Nathalia; Lee, Kwang-Hyuk

    2017-02-01

    Adaptation to delayed sensory feedback following an action produces a subjective time compression between the action and the feedback (temporal recalibration effect, TRE). TRE is important for sensory delay compensation to maintain a relationship between causally related events. It is unclear whether TRE is a sensory modality-specific phenomenon. In 3 experiments employing a sensorimotor synchronization task, we investigated this question using cathodal transcranial direct-current stimulation (tDCS). We found that cathodal tDCS over the visual cortex, and to a lesser extent over the auditory cortex, produced decreased visual TRE. However, both auditory and visual cortex tDCS did not produce any measurable effects on auditory TRE. Our study revealed different nature of TRE in auditory and visual domains. Visual-motor TRE, which is more variable than auditory TRE, is a sensory modality-specific phenomenon, modulated by the auditory cortex. The robustness of auditory-motor TRE, unaffected by tDCS, suggests the dominance of the auditory system in temporal processing, by providing a frame of reference in the realignment of sensorimotor timing signals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Synchronous DC Power Supply.

    Science.gov (United States)

    The patent describes a synchronous direct current (dc) power supply which has the power supply input drive synchronized with the pulse repetition...frequency (PRF) of the amplifying or load circuit requiring the dc power for operation. This limits the occurrence of ripple components in the power ... supply output to the spectral positions of the PRF lines, eliminating ripple interference with signal processing in the load. An astable multivibrator is

  1. Auditory evacuation beacons

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Bronkhorst, A.W.; Boer, L.C.

    2005-01-01

    Auditory evacuation beacons can be used to guide people to safe exits, even when vision is totally obscured by smoke. Conventional beacons make use of modulated noise signals. Controlled evacuation experiments show that such signals require explicit instructions and are often misunderstood. A new

  2. Subcortical processing in auditory communication.

    Science.gov (United States)

    Pannese, Alessia; Grandjean, Didier; Frühholz, Sascha

    2015-10-01

    The voice is a rich source of information, which the human brain has evolved to decode and interpret. Empirical observations have shown that the human auditory system is especially sensitive to the human voice, and that activity within the voice-sensitive regions of the primary and secondary auditory cortex is modulated by the emotional quality of the vocal signal, and may therefore subserve, with frontal regions, the cognitive ability to correctly identify the speaker's affective state. So far, the network involved in the processing of vocal affect has been mainly characterised at the cortical level. However, anatomical and functional evidence suggests that acoustic information relevant to the affective quality of the auditory signal might be processed prior to the auditory cortex. Here we review the animal and human literature on the main subcortical structures along the auditory pathway, and propose a model whereby the distinction between different types of vocal affect in auditory communication begins at very early stages of auditory processing, and relies on the analysis of individual acoustic features of the sound signal. We further suggest that this early feature-based decoding occurs at a subcortical level along the ascending auditory pathway, and provides a preliminary coarse (but fast) characterisation of the affective quality of the auditory signal before the more refined (but slower) cortical processing is completed. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Research on bit synchronization based on GNSS

    Science.gov (United States)

    Yu, Huanran; Liu, Yi-jun

    2017-05-01

    The signals transmitted by GPS satellites are divided into three components: carrier, pseudocode and data code. The processes of signal acquisition are acquisition, tracking, bit synchronization, frame synchronization, navigation message extraction, observation extraction and position speed calculation, among which bit synchronization is of greatest importance. The accuracy of bit synchronization and the shortening of bit synchronization time can help us to use satellite to realize positioning and acquire the information transmitted by satellite signals more accurately. Even under the condition of weak signal, how to improve bit synchronization performance is what we need to research. We adopt a method of polymorphic energy accumulation minima so as to find the bit synchronization point, as well as complete the computer simulation to conclude that under the condition of extremely weak signal power, this method still has superior synchronization performance, which can achieve high bit edge detection rate and the optimal bit error rate.

  4. Auditory Neuropathy

    Science.gov (United States)

    ... with auditory neuropathy have greater impairment in speech perception than hearing health experts would predict based upon their degree of hearing loss on a hearing test. For example, a person with auditory neuropathy may be able to hear ...

  5. EphB2 signaling regulates lesion-induced axon sprouting but not critical period length in the postnatal auditory brainstem

    Directory of Open Access Journals (Sweden)

    Nakamura Paul A

    2013-02-01

    Full Text Available Abstract Background Studies of developmental plasticity may provide insight into plasticity during adulthood, when neural circuitry is less responsive to losses or changes in input. In the mammalian auditory brainstem, globular bushy cell axons of the ventral cochlear nucleus (VCN innervate the contralateral medial nucleus of the trapezoid body (MNTB principal neurons. VCN axonal terminations in MNTB, known as calyces of Held, are very large and specialized for high-fidelity transmission of auditory information. Following unilateral deafferentation during postnatal development, VCN axons from the intact side form connections with novel targets, including the ipsilateral MNTB. EphB signaling has been shown to play a role in this process during the first postnatal week, but mechanisms involved in this reorganization during later developmental periods remain unknown. Results We found that EphB2 signaling reduces the number of induced ipsilateral projections to the MNTB after unilateral VCN removal at postnatal day seven (P7, but not after removal of the VCN on one side at P10, after the closure of the critical period for lesion-induced innervation of the ipsilateral MNTB. Conclusions Results from this study indicate that molecular mechanisms involved in the development of circuitry may also play a part in rewiring after deafferentation during development, but do not appear to regulate the length of critical periods for plasticity.

  6. Digital Synchronizer without Metastability

    Science.gov (United States)

    Simle, Robert M.; Cavazos, Jose A.

    2009-01-01

    A proposed design for a digital synchronizing circuit would eliminate metastability that plagues flip-flop circuits in digital input/output interfaces. This metastability is associated with sampling, by use of flip-flops, of an external signal that is asynchronous with a clock signal that drives the flip-flops: it is a temporary flip-flop failure that can occur when a rising or falling edge of an asynchronous signal occurs during the setup and/or hold time of a flip-flop. The proposed design calls for (1) use of a clock frequency greater than the frequency of the asynchronous signal, (2) use of flip-flop asynchronous preset or clear signals for the asynchronous input, (3) use of a clock asynchronous recovery delay with pulse width discriminator, and (4) tying the data inputs to constant logic levels to obtain (5) two half-rate synchronous partial signals - one for the falling and one for the rising edge. Inasmuch as the flip-flop data inputs would be permanently tied to constant logic levels, setup and hold times would not be violated. The half-rate partial signals would be recombined to construct a signal that would replicate the original asynchronous signal at its original rate but would be synchronous with the clock signal.

  7. Progesterone initiates Wnt-beta-catenin signaling but estradiol is required for nuclear activation and synchronous proliferation of rat uterine stromal cells.

    Science.gov (United States)

    Rider, Virginia; Isuzugawa, Kazuto; Twarog, Meryl; Jones, Stacy; Cameron, Brent; Imakawa, Kazuhiko; Fang, Jianwen

    2006-12-01

    Progesterone pretreatment of ovariectomized rat uteri increases the number of synchronously proliferating stromal cells in response to estradiol 17-beta. To identify the signals involved in stimulating synchronous proliferation, sexually mature ovariectomized rats were injected with progesterone (2 mg) for 3 consecutive days. Estradiol 17-beta (0.2 microg) was administered to initiate cell cycle entry. Uterine samples were removed at various times after hormone administration and changes in wingless (Wnt) pathway effectors and gene targets were identified by microarray. Progesterone pretreatment decreased glycogen synthase kinase-3beta (GSK-3beta) and increased expression of T-cell factor/lymphoid enhancer factor (TCF/LEF). GSK-3beta protein decreased markedly in the uterine stroma of progesterone-pretreated uteri with the concomitant appearance of beta-catenin in these stromal cells. Translocation of beta-catenin from the cytosol to the nuclei in progesterone-pretreated stromal cells was stimulated in response to estradiol. Beta-catenin binding to TCF/LEF increased (P<0.05) in progesterone-pretreated uteri in response to estradiol. Progesterone stimulated the expression of the Wnt target gene urokinase plasminogen activator receptor (uPA-R) in the periluminal uterine stromal cells. The expression of uPA-R increased in progesterone-pretreated stromal cells in response to estradiol administration. Together, the results indicate that progesterone initiates Wnt signaling in the uterine stroma by down-regulating GSK-3beta. However, nuclear translocation of beta-catenin and sufficient complex formation with TCF/LEF to activate stromal cell cycle entry requires estradiol. Stimulation of a uterine stromal cell line to proliferate and differentiate resulted in beta-catenin accumulation, suggesting that endocrine-dependent Wnt signaling controls proliferation and differentiation (decidualization).

  8. Auditory agnosia.

    Science.gov (United States)

    Slevc, L Robert; Shell, Alison R

    2015-01-01

    Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition. © 2015 Elsevier B.V. All rights reserved.

  9. Functional connectivity in the dorsal stream and between bilateral auditory-related cortical areas differentially contribute to speech decoding depending on spectro-temporal signal integrity and performance.

    Science.gov (United States)

    Elmer, Stefan; Kühnis, Jürg; Rauch, Piyush; Abolfazl Valizadeh, Seyed; Jäncke, Lutz

    2017-11-01

    Speech processing relies on the interdependence between auditory perception, sensorimotor integration, and verbal memory functions. Functional and structural connectivity between bilateral auditory-related cortical areas (ARCAs) facilitates spectro-temporal analyses, whereas the dynamic interplay between ARCAs and Broca's area (i.e., dorsal pathway) contributes to verbal memory functions, articulation, and sound-to-motor mapping. However, it remains unclear whether these two neural circuits are preferentially driven by spectral or temporal acoustic information, and whether their recruitment is predictive of speech perception performance and learning. Therefore, we evaluated EEG-based intracranial (eLORETA) functional connectivity (lagged coherence) in both pathways (i.e., between bilateral ARCAs and in the dorsal stream) while good- (GPs, N = 12) and poor performers (PPs, N = 13) learned to decode natural pseudowords (CLEAN) or comparable items (speech-noise chimeras) manipulated in the envelope (ENV) or in the fine-structure (FS). Learning to decode degraded speech was generally associated with increased functional connectivity in the theta, alpha, and beta frequency range in both circuits. Furthermore, GPs exhibited increased connectivity in the left dorsal stream compared to PPs, but only during the FS condition and in the theta frequency band. These results suggest that both pathways contribute to the decoding of spectro-temporal degraded speech by increasing the communication between brain regions involved in perceptual analyses and verbal memory functions. Otherwise, the left-hemispheric recruitment of the dorsal stream in GPs during the FS condition points to a contribution of this pathway to articulatory-based memory processes that are dependent on the temporal integrity of the speech signal. These results enable to better comprehend the neural circuits underlying word-learning as a function of temporal and spectral signal integrity and performance

  10. Demodulation Processes in Auditory Perception

    National Research Council Canada - National Science Library

    Feth, Lawrence

    1997-01-01

    The long range goal of this project was the understanding of human auditory processing of information conveyed by complex, time varying signals such as speech, music or important environmental sounds...

  11. Meaning from environmental sounds: types of signal-referent relations and their effect on recognizing auditory icons.

    Science.gov (United States)

    Keller, Peter; Stevens, Catherine

    2004-03-01

    This article addresses the learnability of auditory icons, that is, environmental sounds that refer either directly or indirectly to meaningful events. Direct relations use the sound made by the target event whereas indirect relations substitute a surrogate for the target. Across 3 experiments, different indirect relations (ecological, in which target and surrogate coexist in the world; metaphorical, in which target and surrogate have similar appearance or function, and random) were compared with one another and with direct relations on measures including associative strength ratings, amount of exposure required for learning, and response times for recognizing icons. Findings suggest that performance is best with direct relations, worst with random relations, and that ecological and metaphorical relations involve distinct types of association but do not differ in learnability.

  12. Synchronization of coupled nonidentical multidelay feedback systems

    International Nuclear Information System (INIS)

    Hoang, Thang Manh; Nakagawa, Masahiro

    2007-01-01

    We present the lag synchronization of coupled nonidentical multidelay feedback systems, in which the synchronization signal is the sum of nonlinearly transformed components of delayed state variable. The sufficient condition for synchronization is considered by the Krasovskii-Lyapunov theory. The specific examples will demonstrate and verify the effectiveness of the proposed model

  13. WE-EF-207-04: An Inter-Projection Sensor Fusion (IPSF) Approach to Estimate Missing Projection Signal in Synchronized Moving Grid (SMOG) System

    International Nuclear Information System (INIS)

    Zhang, H; Kong, V; Jin, J; Ren, L; Zhang, Y; Giles, W

    2015-01-01

    Purpose: A synchronized moving grid (SMOG) has been proposed to reduce scatter and lag artifacts in cone beam computed tomography (CBCT). However, information is missing in each projection because certain areas are blocked by the grid. A previous solution to this issue is acquiring 2 complimentary projections at each position, which increases scanning time. This study reports our first Result using an inter-projection sensor fusion (IPSF) method to estimate missing projection in our prototype SMOG-based CBCT system. Methods: An in-house SMOG assembling with a 1:1 grid of 3 mm gap has been installed in a CBCT benchtop. The grid moves back and forth in a 3-mm amplitude and up-to 20-Hz frequency. A control program in LabView synchronizes the grid motion with the platform rotation and x-ray firing so that the grid patterns for any two neighboring projections are complimentary. A Catphan was scanned with 360 projections. After scatter correction, the IPSF algorithm was applied to estimate missing signal for each projection using the information from the 2 neighboring projections. Feldkamp-Davis-Kress (FDK) algorithm was applied to reconstruct CBCT images. The CBCTs were compared to those reconstructed using normal projections without applying the SMOG system. Results: The SMOG-IPSF method may reduce image dose by half due to the blocked radiation by the grid. The method almost completely removed scatter related artifacts, such as the cupping artifacts. The evaluation of line pair patterns in the CatPhan suggested that the spatial resolution degradation was minimal. Conclusion: The SMOG-IPSF is promising in reducing scatter artifacts and improving image quality while reducing radiation dose

  14. WE-EF-207-04: An Inter-Projection Sensor Fusion (IPSF) Approach to Estimate Missing Projection Signal in Synchronized Moving Grid (SMOG) System

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H; Kong, V; Jin, J [Georgia Regents University Cancer Center, Augusta, GA (Georgia); Ren, L; Zhang, Y; Giles, W [Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: A synchronized moving grid (SMOG) has been proposed to reduce scatter and lag artifacts in cone beam computed tomography (CBCT). However, information is missing in each projection because certain areas are blocked by the grid. A previous solution to this issue is acquiring 2 complimentary projections at each position, which increases scanning time. This study reports our first Result using an inter-projection sensor fusion (IPSF) method to estimate missing projection in our prototype SMOG-based CBCT system. Methods: An in-house SMOG assembling with a 1:1 grid of 3 mm gap has been installed in a CBCT benchtop. The grid moves back and forth in a 3-mm amplitude and up-to 20-Hz frequency. A control program in LabView synchronizes the grid motion with the platform rotation and x-ray firing so that the grid patterns for any two neighboring projections are complimentary. A Catphan was scanned with 360 projections. After scatter correction, the IPSF algorithm was applied to estimate missing signal for each projection using the information from the 2 neighboring projections. Feldkamp-Davis-Kress (FDK) algorithm was applied to reconstruct CBCT images. The CBCTs were compared to those reconstructed using normal projections without applying the SMOG system. Results: The SMOG-IPSF method may reduce image dose by half due to the blocked radiation by the grid. The method almost completely removed scatter related artifacts, such as the cupping artifacts. The evaluation of line pair patterns in the CatPhan suggested that the spatial resolution degradation was minimal. Conclusion: The SMOG-IPSF is promising in reducing scatter artifacts and improving image quality while reducing radiation dose.

  15. A novel joint timing/frequency synchronization scheme based on Radon-Wigner transform of LFM signals in CO-OFDM systems

    Science.gov (United States)

    Liu, Jianfei; Wei, Ying; Zeng, Xiangye; Lu, Jia; Zhang, Shuangxi; Wang, Mengjun

    2018-03-01

    A joint timing and frequency synchronization method has been proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) system in this paper. The timing offset (TO), integer frequency offset (FO) and the fractional FO can be realized by only one training symbol, which consists of two linear frequency modulation (LFM) signals with opposite chirp rates. By detecting the peak of LFM signals after Radon-Wigner transform (RWT), the TO and the integer FO can be estimated at the same time, moreover, the fractional FO can be acquired correspondingly through the self-correlation characteristic of the same training symbol. Simulation results show that the proposed method can give a more accurate TO estimation than the existing methods, especially at poor OSNR conditions; for the FO estimation, both the fractional and the integer FO can be estimated through the proposed training symbol with no extra overhead, a more accurate estimation and a large FO estimation range of [ - 5 GHz, 5GHz] can be acquired.

  16. Synchronized Targeting of Notch and ERBB Signaling Suppresses Melanoma Tumor Growth through Inhibition of Notch1 and ERBB3.

    Science.gov (United States)

    Zhang, Keman; Wong, Poki; Salvaggio, Christine; Salhi, Amel; Osman, Iman; Bedogni, Barbara

    2016-02-01

    Despite significant advances in melanoma therapy, melanoma remains the deadliest form of skin cancer, with a 5-year survival rate of only 15%. Thus, novel treatments are required to address this disease. Notch and ERBB are evolutionarily conserved signaling cascades required for the maintenance of melanocyte precursors. We show that active Notch1 (Notch1(NIC)) and active (phosphorylated) ERBB3 and ERBB2 correlate significantly and are similarly expressed in both mutated and wild-type BRAF melanomas, suggesting these receptors are co-reactivated in melanoma to promote survival. Whereas blocking either pathway triggers modest effects, combining a ?-secretase inhibitor to block Notch activation and a tyrosine kinase inhibitor to inhibit ERBB3/2 elicits synergistic effects, reducing cell viability by 90% and hampering melanoma tumor growth. Specific inhibition of Notch1 and ERBB3 mimics these results, suggesting these are the critical factors triggering melanoma tumor expansion. Notch and ERBB inhibition blunts AKT and NF?B signaling. Constitutive expression of NF?B partially rescues cell death. Blockade of both Notch and ERBB signaling inhibits the slow cycling JARID1B-positive cell population, which is critical for long-term maintenance of melanoma growth. We propose that blocking these pathways is an effective approach to treatment of melanoma patients regardless of whether they carry mutated or wild-type BRAF. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Auditory and Visual Sensations

    CERN Document Server

    Ando, Yoichi

    2010-01-01

    Professor Yoichi Ando, acoustic architectural designer of the Kirishima International Concert Hall in Japan, presents a comprehensive rational-scientific approach to designing performance spaces. His theory is based on systematic psychoacoustical observations of spatial hearing and listener preferences, whose neuronal correlates are observed in the neurophysiology of the human brain. A correlation-based model of neuronal signal processing in the central auditory system is proposed in which temporal sensations (pitch, timbre, loudness, duration) are represented by an internal autocorrelation representation, and spatial sensations (sound location, size, diffuseness related to envelopment) are represented by an internal interaural crosscorrelation function. Together these two internal central auditory representations account for the basic auditory qualities that are relevant for listening to music and speech in indoor performance spaces. Observed psychological and neurophysiological commonalities between auditor...

  18. Intracranial electroencephalography power and phase synchronization changes during monaural and binaural beat stimulation.

    Science.gov (United States)

    Becher, Ann-Katrin; Höhne, Marlene; Axmacher, Nikolai; Chaieb, Leila; Elger, Christian E; Fell, Juergen

    2015-01-01

    Auditory stimulation with monaural or binaural auditory beats (i.e. sine waves with nearby frequencies presented either to both ears or to each ear separately) represents a non-invasive approach to influence electrical brain activity. It is still unclear exactly which brain sites are affected by beat stimulation. In particular, an impact of beat stimulation on mediotemporal brain areas could possibly provide new options for memory enhancement or seizure control. Therefore, we examined how electroencephalography (EEG) power and phase synchronization are modulated by auditory stimulation with beat frequencies corresponding to dominant EEG rhythms based on intracranial recordings in presurgical epilepsy patients. Monaural and binaural beat stimuli with beat frequencies of 5, 10, 40 and 80 Hz and non-superposed control signals were administered with low amplitudes (60 dB SPL) and for short durations (5 s). EEG power was intracranially recorded from mediotemporal, temporo-basal and temporo-lateral and surface sites. Evoked and total EEG power and phase synchronization during beat vs. control stimulation were compared by the use of Bonferroni-corrected non-parametric label-permutation tests. We found that power and phase synchronization were significantly modulated by beat stimulation not only at temporo-basal, temporo-lateral and surface sites, but also at mediotemporal sites. Generally, more significant decreases than increases were observed. The most prominent power increases were seen after stimulation with monaural 40-Hz beats. The most pronounced power and synchronization decreases resulted from stimulation with monaural 5-Hz and binaural 80-Hz beats. Our results suggest that beat stimulation offers a non-invasive approach for the modulation of intracranial EEG characteristics. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. Auditory hallucinations.

    Science.gov (United States)

    Blom, Jan Dirk

    2015-01-01

    Auditory hallucinations constitute a phenomenologically rich group of endogenously mediated percepts which are associated with psychiatric, neurologic, otologic, and other medical conditions, but which are also experienced by 10-15% of all healthy individuals in the general population. The group of phenomena is probably best known for its verbal auditory subtype, but it also includes musical hallucinations, echo of reading, exploding-head syndrome, and many other types. The subgroup of verbal auditory hallucinations has been studied extensively with the aid of neuroimaging techniques, and from those studies emerges an outline of a functional as well as a structural network of widely distributed brain areas involved in their mediation. The present chapter provides an overview of the various types of auditory hallucination described in the literature, summarizes our current knowledge of the auditory networks involved in their mediation, and draws on ideas from the philosophy of science and network science to reconceptualize the auditory hallucinatory experience, and point out directions for future research into its neurobiologic substrates. In addition, it provides an overview of known associations with various clinical conditions and of the existing evidence for pharmacologic and non-pharmacologic treatments. © 2015 Elsevier B.V. All rights reserved.

  20. Selective attention and the auditory vertex potential. I - Effects of stimulus delivery rate. II - Effects of signal intensity and masking noise

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1976-01-01

    The effects of varying the rate of delivery of dichotic tone pip stimuli on selective attention measured by evoked-potential amplitudes and signal detectability scores were studied. The subjects attended to one channel (ear) of tones, ignored the other, and pressed a button whenever occasional targets - tones of a slightly higher pitch were detected in the attended ear. Under separate conditions, randomized interstimulus intervals were short, medium, and long. Another study compared the effects of attention on the N1 component of the auditory evoked potential for tone pips presented alone and when white noise was added to make the tones barely above detectability threshold in a three-channel listening task. Major conclusions are that (1) N1 is enlarged to stimuli in an attended channel only in the short interstimulus interval condition (averaging 350 msec), (2) N1 and P3 are related to different modes of selective attention, and (3) attention selectivity in multichannel listening task is greater when tones are faint and/or difficult to detect.

  1. Subcortical processing in auditory communication

    OpenAIRE

    Pannese, Alessia; Grandjean, Didier Maurice; Frühholz, Sascha

    2015-01-01

    The voice is a rich source of information, which the human brain has evolved to decode and interpret. Empirical observations have shown that the human auditory system is especially sensitive to the human voice, and that activity within the voice-sensitive regions of the primary and secondary auditory cortex is modulated by the emotional quality of the vocal signal, and may therefore subserve, with frontal regions, the cognitive ability to correctly identify the speaker's affective state. So f...

  2. Analytical treatment for synchronizing chaos through unidirectional ...

    Indian Academy of Sciences (India)

    Driving a nonlinear system with a periodic signal is a common feature in nonlinear dynamics. However, the idea of using a chaotic signal to drive a nonlinear system and to maintain synchronization in phase and amplitude of the driving and the driven systems is rather new. The idea of synchronizing two identical chaotic ...

  3. Effect of delayed auditory feedback on stuttering with and without central auditory processing disorders.

    Science.gov (United States)

    Picoloto, Luana Altran; Cardoso, Ana Cláudia Vieira; Cerqueira, Amanda Venuti; Oliveira, Cristiane Moço Canhetti de

    2017-12-07

    To verify the effect of delayed auditory feedback on speech fluency of individuals who stutter with and without central auditory processing disorders. The participants were twenty individuals with stuttering from 7 to 17 years old and were divided into two groups: Stuttering Group with Auditory Processing Disorders (SGAPD): 10 individuals with central auditory processing disorders, and Stuttering Group (SG): 10 individuals without central auditory processing disorders. Procedures were: fluency assessment with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF), assessment of the stuttering severity and central auditory processing (CAP). Phono Tools software was used to cause a delay of 100 milliseconds in the auditory feedback. The "Wilcoxon Signal Post" test was used in the intragroup analysis and "Mann-Whitney" test in the intergroup analysis. The DAF caused a statistically significant reduction in SG: in the frequency score of stuttering-like disfluencies in the analysis of the Stuttering Severity Instrument, in the amount of blocks and repetitions of monosyllabic words, and in the frequency of stuttering-like disfluencies of duration. Delayed auditory feedback did not cause statistically significant effects on SGAPD fluency, individuals with stuttering with auditory processing disorders. The effect of delayed auditory feedback in speech fluency of individuals who stutter was different in individuals of both groups, because there was an improvement in fluency only in individuals without auditory processing disorder.

  4. Early auditory enrichment with music enhances auditory discrimination learning and alters NR2B protein expression in rat auditory cortex.

    Science.gov (United States)

    Xu, Jinghong; Yu, Liping; Cai, Rui; Zhang, Jiping; Sun, Xinde

    2009-01-03

    Previous studies have shown that the functional development of auditory system is substantially influenced by the structure of environmental acoustic inputs in early life. In our present study, we investigated the effects of early auditory enrichment with music on rat auditory discrimination learning. We found that early auditory enrichment with music from postnatal day (PND) 14 enhanced learning ability in auditory signal-detection task and in sound duration-discrimination task. In parallel, a significant increase was noted in NMDA receptor subunit NR2B protein expression in the auditory cortex. Furthermore, we found that auditory enrichment with music starting from PND 28 or 56 did not influence NR2B expression in the auditory cortex. No difference was found in the NR2B expression in the inferior colliculus (IC) between music-exposed and normal rats, regardless of when the auditory enrichment with music was initiated. Our findings suggest that early auditory enrichment with music influences NMDA-mediated neural plasticity, which results in enhanced auditory discrimination learning.

  5. Presbycusis and auditory brainstem responses: a review

    Directory of Open Access Journals (Sweden)

    Shilpa Khullar

    2011-06-01

    Full Text Available Age-related hearing loss or presbycusis is a complex phenomenon consisting of elevation of hearing levels as well as changes in the auditory processing. It is commonly classified into four categories depending on the cause. Auditory brainstem responses (ABRs are a type of early evoked potentials recorded within the first 10 ms of stimulation. They represent the synchronized activity of the auditory nerve and the brainstem. Some of the changes that occur in the aging auditory system may significantly influence the interpretation of the ABRs in comparison with the ABRs of the young adults. The waves of ABRs are described in terms of amplitude, latencies and interpeak latency of the different waves. There is a tendency of the amplitude to decrease and the absolute latencies to increase with advancing age but these trends are not always clear due to increase in threshold with advancing age that act a major confounding factor in the interpretation of ABRs.

  6. Evoked responses of the superior olive to amplitude-modulated signals.

    Science.gov (United States)

    Andreeva, N G; Lang, T T

    1977-01-01

    Evoked potentials of some auditory centers of Rhinolophidae bats to amplitude-modulated signals were studied. A synchronization response was found in the cochlear nuclei (with respect to the fast component of the response) and in the superior olivary complex (with respect to both fast and slow components of the response) within the range of frequency modulation from 50 to 2000 Hz. In the inferior colliculus a synchronized response was recorded at modulation frequencies below 150 Hz, but in the medial geniculate bodies no such response was found. Evoked responses of the superior olivary complex were investigated in detail. The lowest frequencies of synchronization were recorded within the carrier frequency range of 15-30 and 80-86 kHz. The amplitude of the synchronized response is a function of the frequency and coefficient of modulation and also of the angle of stimulus presentation.

  7. Method for Converter Synchronization with RF Injection

    OpenAIRE

    Joshua P. Bruckmeyer; Ivica Kostanic

    2015-01-01

    This paper presents an injection method for synchronizing analog to digital converters (ADC). This approach can eliminate the need for precision routed discrete synchronization signals of current technologies, such as JESD204. By eliminating the setup and hold time requirements at the conversion (or near conversion) clock rate, higher sample rate systems can be synchronized. Measured data from an existing multiple ADC conversion system was used to evaluate the method. Coherent beams were simu...

  8. The synchronization of three fractional differential systems

    International Nuclear Information System (INIS)

    Li Changpin; Yan Jianping

    2007-01-01

    In this paper, a new method is proposed and applied to the synchronization of fractional differential systems (or 'differential systems with fractional orders'), where both drive and response systems have the same dimensionality and are coupled by the driving signal. The present technique is based on the stability criterion of linear fractional systems. This method is implemented in (chaos) synchronization of the fractional Lorenz system, Chen system and Chua circuit. Numerical simulations show the present synchronization method works well

  9. Complexity and synchronization in stochastic chaotic systems

    Science.gov (United States)

    Son Dang, Thai; Palit, Sanjay Kumar; Mukherjee, Sayan; Hoang, Thang Manh; Banerjee, Santo

    2016-02-01

    We investigate the complexity of a hyperchaotic dynamical system perturbed by noise and various nonlinear speech and music signals. The complexity is measured by the weighted recurrence entropy of the hyperchaotic and stochastic systems. The synchronization phenomenon between two stochastic systems with complex coupling is also investigated. These criteria are tested on chaotic and perturbed systems by mean conditional recurrence and normalized synchronization error. Numerical results including surface plots, normalized synchronization errors, complexity variations etc show the effectiveness of the proposed analysis.

  10. Analyse d'une méthode D.L.T.S. utilisant une détection synchrone mesurant l'harmonique deux du signal de capacité

    OpenAIRE

    Le Bloa, A.; Favennec, P.N.

    1982-01-01

    Nous décrivons une méthode D.L.T.S. utilisant une détection synchrone dont la mise en oeuvre est simple ; cette méthode réduit l'influence sur les mesures de la réponse transitoire du capacimètre et élimine la composante continue de la capacité. La détection de l'harmonique deux présente alors une meilleure sélectivité que la détection du fondamental. La limitation à une demi-période du signal de capacité à l'entrée de la détection synchrone réduit le bruit de fond pour les coefficients de Fo...

  11. Deciphering auditory processing disorders in children.

    Science.gov (United States)

    Chermak, Gail D

    2002-08-01

    APD is not a label for a unitary disease entity but rather a description of functional deficits [3]. It is a complex and heterogeneous group of auditory-specific disorders usually associated with a range of listening and learning deficits [3,4]. Underlying APD is a deficit observed in one or more of the auditory processes responsible for generating the auditory evoked potentials and the following behaviors: around localization and lateralization; auditory discrimination; auditory pattern recognition; temporal aspects of audition, including temporal resolution, masking, integration, and ordering; auditory performance with competing acoustic signals; and auditory performance with degraded acoustic signals [2]. Comprehensive assessment is necessary for the accurate differential diagnosis of APD from other "look-alike" disorders, most notably ADHD and language processing disorders. Speech-language pathologists, psychologists, educators, and physicians contribute to this more comprehensive assessment. The primary role of otolaryngologists is to evaluate and treat peripheral hearing disorders, such as otitis media. Children with APDs may present to an otolaryngologist, thus requiring the physician to make appropriate referral for assessment and intervention. Currently, diagnosis of APD is based on the outcomes of behavioral tests, supplemented by electroacoustic measures and, to a lesser extent, by electrophysiologic measures [1]. Intervention for APD focuses on improving the quality of the acoustic signal and the listening environment, improving auditory skills, and enhancing utilization of metacognitive and language resources [2]. Additional controlled case studies and single-subject and group research designs are needed to ascertain systematically the relative efficacy of various treatment and management approaches.

  12. Main injector synchronous timing system

    International Nuclear Information System (INIS)

    Blokland, W.; Steimel, J.

    1998-01-01

    The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System. copyright 1998 American Institute of Physics

  13. Main injector synchronous timing system

    International Nuclear Information System (INIS)

    Blokland, Willem; Steimel, James

    1998-01-01

    The Synchronous Timing System is designed to provide sub-nanosecond timing to instrumentation during the acceleration of particles in the Main Injector. Increased energy of the beam particles leads to a small but significant increase in speed, reducing the time it takes to complete a full turn of the ring by 61 nanoseconds (or more than 3 rf buckets). In contrast, the reference signal, used to trigger instrumentation and transmitted over a cable, has a constant group delay. This difference leads to a phase slip during the ramp and prevents instrumentation such as dampers from properly operating without additional measures. The Synchronous Timing System corrects for this phase slip as well as signal propagation time changes due to temperature variations. A module at the LLRF system uses a 1.2 Gbit/s G-Link chip to transmit the rf clock and digital data (e.g. the current frequency) over a single mode fiber around the ring. Fiber optic couplers at service buildings split off part of this signal for a local module which reconstructs a synchronous beam reference signal. This paper describes the background, design and expected performance of the Synchronous Timing System

  14. [Auditory fatigue].

    Science.gov (United States)

    Sanjuán Juaristi, Julio; Sanjuán Martínez-Conde, Mar

    2015-01-01

    Given the relevance of possible hearing losses due to sound overloads and the short list of references of objective procedures for their study, we provide a technique that gives precise data about the audiometric profile and recruitment factor. Our objectives were to determine peripheral fatigue, through the cochlear microphonic response to sound pressure overload stimuli, as well as to measure recovery time, establishing parameters for differentiation with regard to current psychoacoustic and clinical studies. We used specific instruments for the study of cochlear microphonic response, plus a function generator that provided us with stimuli of different intensities and harmonic components. In Wistar rats, we first measured the normal microphonic response and then the effect of auditory fatigue on it. Using a 60dB pure tone acoustic stimulation, we obtained a microphonic response at 20dB. We then caused fatigue with 100dB of the same frequency, reaching a loss of approximately 11dB after 15minutes; after that, the deterioration slowed and did not exceed 15dB. By means of complex random tone maskers or white noise, no fatigue was caused to the sensory receptors, not even at levels of 100dB and over an hour of overstimulation. No fatigue was observed in terms of sensory receptors. Deterioration of peripheral perception through intense overstimulation may be due to biochemical changes of desensitisation due to exhaustion. Auditory fatigue in subjective clinical trials presumably affects supracochlear sections. The auditory fatigue tests found are not in line with those obtained subjectively in clinical and psychoacoustic trials. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  15. Feeling the Beat: Bouncing Synchronization to Vibrotactile Music in Hearing and Early Deaf People.

    Science.gov (United States)

    Tranchant, Pauline; Shiell, Martha M; Giordano, Marcello; Nadeau, Alexis; Peretz, Isabelle; Zatorre, Robert J

    2017-01-01

    The ability to dance relies on the ability to synchronize movements to a perceived musical beat. Typically, beat synchronization is studied with auditory stimuli. However, in many typical social dancing situations, music can also be perceived as vibrations when objects that generate sounds also generate vibrations. This vibrotactile musical perception is of particular relevance for deaf people, who rely on non-auditory sensory information for dancing. In the present study, we investigated beat synchronization to vibrotactile electronic dance music in hearing and deaf people. We tested seven deaf and 14 hearing individuals on their ability to bounce in time with the tempo of vibrotactile stimuli (no sound) delivered through a vibrating platform. The corresponding auditory stimuli (no vibrations) were used in an additional condition in the hearing group. We collected movement data using a camera-based motion capture system and subjected it to a phase-locking analysis to assess synchronization quality. The vast majority of participants were able to precisely time their bounces to the vibrations, with no difference in performance between the two groups. In addition, we found higher performance for the auditory condition compared to the vibrotactile condition in the hearing group. Our results thus show that accurate tactile-motor synchronization in a dance-like context occurs regardless of auditory experience, though auditory-motor synchronization is of superior quality.

  16. Feeling the Beat: Bouncing Synchronization to Vibrotactile Music in Hearing and Early Deaf People

    Directory of Open Access Journals (Sweden)

    Pauline Tranchant

    2017-09-01

    Full Text Available The ability to dance relies on the ability to synchronize movements to a perceived musical beat. Typically, beat synchronization is studied with auditory stimuli. However, in many typical social dancing situations, music can also be perceived as vibrations when objects that generate sounds also generate vibrations. This vibrotactile musical perception is of particular relevance for deaf people, who rely on non-auditory sensory information for dancing. In the present study, we investigated beat synchronization to vibrotactile electronic dance music in hearing and deaf people. We tested seven deaf and 14 hearing individuals on their ability to bounce in time with the tempo of vibrotactile stimuli (no sound delivered through a vibrating platform. The corresponding auditory stimuli (no vibrations were used in an additional condition in the hearing group. We collected movement data using a camera-based motion capture system and subjected it to a phase-locking analysis to assess synchronization quality. The vast majority of participants were able to precisely time their bounces to the vibrations, with no difference in performance between the two groups. In addition, we found higher performance for the auditory condition compared to the vibrotactile condition in the hearing group. Our results thus show that accurate tactile-motor synchronization in a dance-like context occurs regardless of auditory experience, though auditory-motor synchronization is of superior quality.

  17. Auditory prediction during speaking and listening.

    Science.gov (United States)

    Sato, Marc; Shiller, Douglas M

    2018-02-02

    In the present EEG study, the role of auditory prediction in speech was explored through the comparison of auditory cortical responses during active speaking and passive listening to the same acoustic speech signals. Two manipulations of sensory prediction accuracy were used during the speaking task: (1) a real-time change in vowel F1 feedback (reducing prediction accuracy relative to unaltered feedback) and (2) presenting a stable auditory target rather than a visual cue to speak (enhancing auditory prediction accuracy during baseline productions, and potentially enhancing the perturbing effect of altered feedback). While subjects compensated for the F1 manipulation, no difference between the auditory-cue and visual-cue conditions were found. Under visually-cued conditions, reduced N1/P2 amplitude was observed during speaking vs. listening, reflecting a motor-to-sensory prediction. In addition, a significant correlation was observed between the magnitude of behavioral compensatory F1 response and the magnitude of this speaking induced suppression (SIS) for P2 during the altered auditory feedback phase, where a stronger compensatory decrease in F1 was associated with a stronger the SIS effect. Finally, under the auditory-cued condition, an auditory repetition-suppression effect was observed in N1/P2 amplitude during the listening task but not active speaking, suggesting that auditory predictive processes during speaking and passive listening are functionally distinct. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Illumination-based synchronization of high-speed vision sensors.

    Science.gov (United States)

    Hou, Lei; Kagami, Shingo; Hashimoto, Koichi

    2010-01-01

    To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. This paper describes an illumination-based synchronization method derived from the phase-locked loop (PLL) algorithm. Incident light to a vision sensor from an intensity-modulated illumination source serves as the reference signal for synchronization. Analog and digital computation within the vision sensor forms a PLL to regulate the output signal, which corresponds to the vision frame timing, to be synchronized with the reference. Simulated and experimental results show that a 1,000 Hz frame rate vision sensor was successfully synchronized with 32 μs jitters.

  19. Contributions of sensory tuning to auditory-vocal interactions in marmoset auditory cortex.

    Science.gov (United States)

    Eliades, Steven J; Wang, Xiaoqin

    2017-05-01

    During speech, humans continuously listen to their own vocal output to ensure accurate communication. Such self-monitoring is thought to require the integration of information about the feedback of vocal acoustics with internal motor control signals. The neural mechanism of this auditory-vocal interaction remains largely unknown at the cellular level. Previous studies in naturally vocalizing marmosets have demonstrated diverse neural activities in auditory cortex during vocalization, dominated by a vocalization-induced suppression of neural firing. How underlying auditory tuning properties of these neurons might contribute to this sensory-motor processing is unknown. In the present study, we quantitatively compared marmoset auditory cortex neural activities during vocal production with those during passive listening. We found that neurons excited during vocalization were readily driven by passive playback of vocalizations and other acoustic stimuli. In contrast, neurons suppressed during vocalization exhibited more diverse playback responses, including responses that were not predictable by auditory tuning properties. These results suggest that vocalization-related excitation in auditory cortex is largely a sensory-driven response. In contrast, vocalization-induced suppression is not well predicted by a neuron's auditory responses, supporting the prevailing theory that internal motor-related signals contribute to the auditory-vocal interaction observed in auditory cortex. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Anti-synchronization Between Coupled Networks with Two Active Forms

    International Nuclear Information System (INIS)

    Wu Yongqing; Sun Weigang; Li Shanshan

    2011-01-01

    This paper studies anti-synchronization and its control between two coupled networks with nonlinear signal's connection and the inter-network actions. If anti-synchronization does not exist between two such networks, adaptive controllers are designed to anti-synchronize them. Different node dynamics and nonidentical topological structures are considered and useful criteria for anti-synchronization between two networks are given. Numerical examples are presented to show the efficiency of our derived results. (general)

  1. Semantic congruency of auditory warnings.

    Science.gov (United States)

    Isherwood, Sarah J; McKeown, Denis

    2017-07-01

    The aim of this study was to explore operator experience and performance for semantically congruent and incongruent auditory icons and abstract alarm sounds. It was expected that performance advantages for congruent sounds would be present initially but would reduce over time for both alarm types. Twenty-four participants (12M/12F) were placed into auditory icon or abstract alarm groupings. For each group both congruent and incongruent alarms were used to represent different driving task scenarios. Once sounded, participants were required to respond to each alarm by selecting a corresponding driving scenario. User performance for all sound types improved over time, however even with experience a decrement in speed of response remained for the incongruent iconic sounds and in accuracy of performance for the abstract warning sounds when compared to the congruent auditory icons. Semantic congruency was found to be of more importance for auditory icons than for abstract sounds. Practitioner Summary: Alarms are used in many operating systems as emergency, alerting, or continuous monitoring signals for instance. This study found that the type and representativeness of an auditory warning will influence operator performance over time. Semantically congruent iconic sounds produced performance advantages over both incongruent iconic sounds and abstract warnings.

  2. The evolutionary neuroscience of musical beat perception: the Action Simulation for Auditory Prediction (ASAP hypothesis.

    Directory of Open Access Journals (Sweden)

    Aniruddh D. Patel

    2014-05-01

    Full Text Available Every human culture has some form of music with a beat: a perceived periodic pulse that structures the perception of musical rhythm and which serves as a framework for synchronized movement to music. What are the neural mechanisms of musical beat perception, and how did they evolve? One view, which dates back to Darwin and implicitly informs some current models of beat perception, is that the relevant neural mechanisms are relatively general and are widespread among animal species. On the basis of recent neural and cross-species data on musical beat processing, this paper argues for a different view. Here we argue that beat perception is a complex brain function involving temporally-precise communication between auditory regions and motor planning regions of the cortex (even in the absence of overt movement. More specifically, we propose that simulation of periodic movement in motor planning regions provides a neural signal that helps the auditory system predict the timing of upcoming beats. This action simulation for auditory prediction (ASAP hypothesis leads to testable predictions. We further suggest that ASAP relies on dorsal auditory pathway connections between auditory regions and motor planning regions via the parietal cortex, and suggest that these connections may be stronger in humans than in nonhuman primates due to the evolution of vocal learning in our lineage. This suggestion motivates cross-species research to determine which species are capable of human-like beat perception, i.e., beat perception that involves accurate temporal prediction of beat times across a fairly broad range of tempi.

  3. Auditory-visual interactions subserving goal-directed saccades in a complex scene.

    Science.gov (United States)

    Corneil, B D; Van Wanrooij, M; Munoz, D P; Van Opstal, A J

    2002-07-01

    -saccades, the improvements in SRT and accuracy of AV-saccades were greatest when the visual target was synchronous with or leading the auditory target, and when the S/N ratio of the auditory target was lowest. Further, the improvements in saccade accuracy were greater in elevation than in azimuth. A control experiment demonstrated that a portion of the improvements in SRT could be attributable to a warning-cue mechanism, but that the improvements in saccade accuracy depended on the spatial register of the stimuli. These results agree well with earlier electrophysiological results obtained from the midbrain superior colliculus (SC) of anesthetized preparations, and we argue that they demonstrate multisensory integration of auditory and visual signals in a complex, quasi-natural environment. A conceptual model incorporating the SC is presented to explain the observed data.

  4. Auditory conflict and congruence in frontotemporal dementia.

    Science.gov (United States)

    Clark, Camilla N; Nicholas, Jennifer M; Agustus, Jennifer L; Hardy, Christopher J D; Russell, Lucy L; Brotherhood, Emilie V; Dick, Katrina M; Marshall, Charles R; Mummery, Catherine J; Rohrer, Jonathan D; Warren, Jason D

    2017-09-01

    Impaired analysis of signal conflict and congruence may contribute to diverse socio-emotional symptoms in frontotemporal dementias, however the underlying mechanisms have not been defined. Here we addressed this issue in patients with behavioural variant frontotemporal dementia (bvFTD; n = 19) and semantic dementia (SD; n = 10) relative to healthy older individuals (n = 20). We created auditory scenes in which semantic and emotional congruity of constituent sounds were independently probed; associated tasks controlled for auditory perceptual similarity, scene parsing and semantic competence. Neuroanatomical correlates of auditory congruity processing were assessed using voxel-based morphometry. Relative to healthy controls, both the bvFTD and SD groups had impaired semantic and emotional congruity processing (after taking auditory control task performance into account) and reduced affective integration of sounds into scenes. Grey matter correlates of auditory semantic congruity processing were identified in distributed regions encompassing prefrontal, parieto-temporal and insular areas and correlates of auditory emotional congruity in partly overlapping temporal, insular and striatal regions. Our findings suggest that decoding of auditory signal relatedness may probe a generic cognitive mechanism and neural architecture underpinning frontotemporal dementia syndromes. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  5. Demodulation processes in auditory perception

    Science.gov (United States)

    Feth, Lawrence L.

    1994-08-01

    The long range goal of this project is the understanding of human auditory processing of information conveyed by complex, time-varying signals such as speech, music or important environmental sounds. Our work is guided by the assumption that human auditory communication is a 'modulation - demodulation' process. That is, we assume that sound sources produce a complex stream of sound pressure waves with information encoded as variations ( modulations) of the signal amplitude and frequency. The listeners task then is one of demodulation. Much of past. psychoacoustics work has been based in what we characterize as 'spectrum picture processing.' Complex sounds are Fourier analyzed to produce an amplitude-by-frequency 'picture' and the perception process is modeled as if the listener were analyzing the spectral picture. This approach leads to studies such as 'profile analysis' and the power-spectrum model of masking. Our approach leads us to investigate time-varying, complex sounds. We refer to them as dynamic signals and we have developed auditory signal processing models to help guide our experimental work.

  6. Neural oscillations in auditory working memory

    OpenAIRE

    Wilsch, A.

    2015-01-01

    The present thesis investigated memory load and memory decay in auditory working memory. Alpha power as a marker for memory load served as the primary indicator for load and decay fluctuations hypothetically reflecting functional inhibition of irrelevant information. Memory load was induced by presenting auditory signals (syllables and pure-tone sequences) in noise because speech-in-noise has been shown before to increase memory load. The aim of the thesis was to assess with magnetoencephalog...

  7. Amygdala and auditory cortex exhibit distinct sensitivity to relevant acoustic features of auditory emotions.

    Science.gov (United States)

    Pannese, Alessia; Grandjean, Didier; Frühholz, Sascha

    2016-12-01

    Discriminating between auditory signals of different affective value is critical to successful social interaction. It is commonly held that acoustic decoding of such signals occurs in the auditory system, whereas affective decoding occurs in the amygdala. However, given that the amygdala receives direct subcortical projections that bypass the auditory cortex, it is possible that some acoustic decoding occurs in the amygdala as well, when the acoustic features are relevant for affective discrimination. We tested this hypothesis by combining functional neuroimaging with the neurophysiological phenomena of repetition suppression (RS) and repetition enhancement (RE) in human listeners. Our results show that both amygdala and auditory cortex responded differentially to physical voice features, suggesting that the amygdala and auditory cortex decode the affective quality of the voice not only by processing the emotional content from previously processed acoustic features, but also by processing the acoustic features themselves, when these are relevant to the identification of the voice's affective value. Specifically, we found that the auditory cortex is sensitive to spectral high-frequency voice cues when discriminating vocal anger from vocal fear and joy, whereas the amygdala is sensitive to vocal pitch when discriminating between negative vocal emotions (i.e., anger and fear). Vocal pitch is an instantaneously recognized voice feature, which is potentially transferred to the amygdala by direct subcortical projections. These results together provide evidence that, besides the auditory cortex, the amygdala too processes acoustic information, when this is relevant to the discrimination of auditory emotions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Sensorimotor Synchronization with Different Metrical Levels of Point-Light Dance Movements.

    Science.gov (United States)

    Su, Yi-Huang

    2016-01-01

    Rhythm perception and synchronization have been extensively investigated in the auditory domain, as they underlie means of human communication such as music and speech. Although recent studies suggest comparable mechanisms for synchronizing with periodically moving visual objects, the extent to which it applies to ecologically relevant information, such as the rhythm of complex biological motion, remains unknown. The present study addressed this issue by linking rhythm of music and dance in the framework of action-perception coupling. As a previous study showed that observers perceived multiple metrical periodicities in dance movements that embodied this structure, the present study examined whether sensorimotor synchronization (SMS) to dance movements resembles what is known of auditory SMS. Participants watched a point-light figure performing two basic steps of Swing dance cyclically, in which the trunk bounced at every beat and the limbs moved at every second beat, forming two metrical periodicities. Participants tapped synchronously to the bounce of the trunk with or without the limbs moving in the stimuli (Experiment 1), or tapped synchronously to the leg movements with or without the trunk bouncing simultaneously (Experiment 2). Results showed that, while synchronization with the bounce (lower-level pulse) was not influenced by the presence or absence of limb movements (metrical accent), synchronization with the legs (beat) was improved by the presence of the bounce (metrical subdivision) across different movement types. The latter finding parallels the "subdivision benefit" often demonstrated in auditory tasks, suggesting common sensorimotor mechanisms for visual rhythms in dance and auditory rhythms in music.

  9. Functional role of delta and theta band oscillations for auditory feedback processing during vocal pitch motor control

    Directory of Open Access Journals (Sweden)

    Roozbeh eBehroozmand

    2015-03-01

    Full Text Available The answer to the question of how the brain incorporates sensory feedback and links it with motor function to achieve goal-directed movement during vocalization remains unclear. We investigated the mechanisms of voice pitch motor control by examining the spectro-temporal dynamics of EEG signals when non-musicians (NM, relative pitch (RP and absolute pitch (AP musicians maintained vocalizations of a vowel sound and received randomized ±100 cents pitch-shift stimuli in their auditory feedback. We identified a phase-synchronized (evoked fronto-central activation within the theta band (5-8 Hz that temporally overlapped with compensatory vocal responses to pitch-shifted auditory feedback and was significantly stronger in RP and AP musicians compared with non-musicians. A second component involved a non-phase-synchronized (induced frontal activation within the delta band (1-4 Hz that emerged at approximately 1 second after the stimulus onset. The delta activation was significantly stronger in the NM compared with RP and AP groups and correlated with the pitch rebound error (PRE, indicating the degree to which subjects failed to re-adjust their voice pitch to baseline after the stimulus offset. We propose that the evoked theta is a neurophysiological marker of enhanced pitch processing in musicians and reflects mechanisms by which humans incorporate auditory feedback to control their voice pitch. We also suggest that the delta activation reflects adaptive neural processes by which vocal production errors are monitored and used to update the state of sensory-motor networks for driving subsequent vocal behaviors. This notion is corroborated by our findings showing that larger PREs were associated with greater delta band activity in the NM compared with RP and AP groups. These findings provide new insights into the neural mechanisms of auditory feedback processing for vocal pitch motor control.

  10. Multisensory stimuli improve relative localisation judgments compared to unisensory auditory or visual stimuli

    OpenAIRE

    Bizley, Jennifer; Wood, Katherine; Freeman, Laura

    2018-01-01

    Observers performed a relative localisation task in which they reported whether the second of two sequentially presented signals occurred to the left or right of the first. Stimuli were detectability-matched auditory, visual, or auditory-visual signals and the goal was to compare changes in performance with eccentricity across modalities. Visual performance was superior to auditory at the midline, but inferior in the periphery, while auditory-visual performance exceeded both at all locations....

  11. Characterization of auditory synaptic inputs to gerbil perirhinal cortex

    Directory of Open Access Journals (Sweden)

    Vibhakar C Kotak

    2015-08-01

    Full Text Available The representation of acoustic cues involves regions downstream from the auditory cortex (ACx. One such area, the perirhinal cortex (PRh, processes sensory signals containing mnemonic information. Therefore, our goal was to assess whether PRh receives auditory inputs from the auditory thalamus (MG and ACx in an auditory thalamocortical brain slice preparation and characterize these afferent-driven synaptic properties. When the MG or ACx was electrically stimulated, synaptic responses were recorded from the PRh neurons. Blockade of GABA-A receptors dramatically increased the amplitude of evoked excitatory potentials. Stimulation of the MG or ACx also evoked calcium transients in most PRh neurons. Separately, when fluoro ruby was injected in ACx in vivo, anterogradely labeled axons and terminals were observed in the PRh. Collectively, these data show that the PRh integrates auditory information from the MG and ACx and that auditory driven inhibition dominates the postsynaptic responses in a non-sensory cortical region downstream from the auditory cortex.

  12. Coupling between Theta Oscillations and Cognitive Control Network during Cross-Modal Visual and Auditory Attention: Supramodal vs Modality-Specific Mechanisms.

    Science.gov (United States)

    Wang, Wuyi; Viswanathan, Shivakumar; Lee, Taraz; Grafton, Scott T

    2016-01-01

    Cortical theta band oscillations (4-8 Hz) in EEG signals have been shown to be important for a variety of different cognitive control operations in visual attention paradigms. However the synchronization source of these signals as defined by fMRI BOLD activity and the extent to which theta oscillations play a role in multimodal attention remains unknown. Here we investigated the extent to which cross-modal visual and auditory attention impacts theta oscillations. Using a simultaneous EEG-fMRI paradigm, healthy human participants performed an attentional vigilance task with six cross-modal conditions using naturalistic stimuli. To assess supramodal mechanisms, modulation of theta oscillation amplitude for attention to either visual or auditory stimuli was correlated with BOLD activity by conjunction analysis. Negative correlation was localized to cortical regions associated with the default mode network and positively with ventral premotor areas. Modality-associated attention to visual stimuli was marked by a positive correlation of theta and BOLD activity in fronto-parietal area that was not observed in the auditory condition. A positive correlation of theta and BOLD activity was observed in auditory cortex, while a negative correlation of theta and BOLD activity was observed in visual cortex during auditory attention. The data support a supramodal interaction of theta activity with of DMN function, and modality-associated processes within fronto-parietal networks related to top-down theta related cognitive control in cross-modal visual attention. On the other hand, in sensory cortices there are opposing effects of theta activity during cross-modal auditory attention.

  13. Cluster Synchronization Algorithms

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2010-01-01

    This paper presents two approaches to achieving cluster synchronization in dynamical multi-agent systems. In contrast to the widely studied synchronization behavior, where all the coupled agents converge to the same value asymptotically, in the cluster synchronization problem studied in this paper,

  14. Auditory Feedback Differentially Modulates Behavioral and Neural Markers of Objective and Subjective Performance When Tapping to Your Heartbeat

    Science.gov (United States)

    Canales-Johnson, Andrés; Silva, Carolina; Huepe, David; Rivera-Rei, Álvaro; Noreika, Valdas; Garcia, María del Carmen; Silva, Walter; Ciraolo, Carlos; Vaucheret, Esteban; Sedeño, Lucas; Couto, Blas; Kargieman, Lucila; Baglivo, Fabricio; Sigman, Mariano; Chennu, Srivas; Ibáñez, Agustín; Rodríguez, Eugenio; Bekinschtein, Tristan A.

    2015-01-01

    Interoception, the perception of our body internal signals, plays a key role in maintaining homeostasis and guiding our behavior. Sometimes, we become aware of our body signals and use them in planning and strategic thinking. Here, we show behavioral and neural dissociations between learning to follow one's own heartbeat and metacognitive awareness of one's performance, in a heartbeat-tapping task performed before and after auditory feedback. The electroencephalography amplitude of the heartbeat-evoked potential in interoceptive learners, that is, participants whose accuracy of tapping to their heartbeat improved after auditory feedback, was higher compared with non-learners. However, an increase in gamma phase synchrony (30–45 Hz) after the heartbeat auditory feedback was present only in those participants showing agreement between objective interoceptive performance and metacognitive awareness. Source localization in a group of participants and direct cortical recordings in a single patient identified a network hub for interoceptive learning in the insular cortex. In summary, interoceptive learning may be mediated by the right insular response to the heartbeat, whereas metacognitive awareness of learning may be mediated by widespread cortical synchronization patterns. PMID:25899708

  15. Synchronization System for Next Generation Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zavriyev, Anton [MagiQ Technologies, Inc., Somerville, MA (United States)

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  16. Auditory Imagery: Empirical Findings

    Science.gov (United States)

    Hubbard, Timothy L.

    2010-01-01

    The empirical literature on auditory imagery is reviewed. Data on (a) imagery for auditory features (pitch, timbre, loudness), (b) imagery for complex nonverbal auditory stimuli (musical contour, melody, harmony, tempo, notational audiation, environmental sounds), (c) imagery for verbal stimuli (speech, text, in dreams, interior monologue), (d)…

  17. Temporal factors affecting somatosensory-auditory interactions in speech processing

    Directory of Open Access Journals (Sweden)

    Takayuki eIto

    2014-11-01

    Full Text Available Speech perception is known to rely on both auditory and visual information. However, sound specific somatosensory input has been shown also to influence speech perceptual processing (Ito et al., 2009. In the present study we addressed further the relationship between somatosensory information and speech perceptual processing by addressing the hypothesis that the temporal relationship between orofacial movement and sound processing contributes to somatosensory-auditory interaction in speech perception. We examined the changes in event-related potentials in response to multisensory synchronous (simultaneous and asynchronous (90 ms lag and lead somatosensory and auditory stimulation compared to individual unisensory auditory and somatosensory stimulation alone. We used a robotic device to apply facial skin somatosensory deformations that were similar in timing and duration to those experienced in speech production. Following synchronous multisensory stimulation the amplitude of the event-related potential was reliably different from the two unisensory potentials. More importantly, the magnitude of the event-related potential difference varied as a function of the relative timing of the somatosensory-auditory stimulation. Event-related activity change due to stimulus timing was seen between 160-220 ms following somatosensory onset, mostly around the parietal area. The results demonstrate a dynamic modulation of somatosensory-auditory convergence and suggest the contribution of somatosensory information for speech processing process is dependent on the specific temporal order of sensory inputs in speech production.

  18. Magnetic resonance imaging of the internal auditory canal

    International Nuclear Information System (INIS)

    Daniels, D.L.; Herfkins, R.; Koehler, P.R.; Millen, S.J.; Shaffer, K.A.; Williams, A.L.; Haughton, V.M.

    1984-01-01

    Three patients with exclusively or predominantly intracanalicular neuromas and 5 with presumably normal internal auditory canals were examined with prototype 1.4- or 1.5-tesla magnetic resonance (MR) scanners. MR images showed the 7th and 8th cranial nerves in the internal auditory canal. The intracanalicular neuromas had larger diameter and slightly greater signal strength than the nerves. Early results suggest that minimal enlargement of the nerves can be detected even in the internal auditory canal

  19. Auditory perception in individuals with Friedreich's ataxia.

    Science.gov (United States)

    Rance, Gary; Corben, Louise; Barker, Elizabeth; Carew, Peter; Chisari, Donella; Rogers, Meghan; Dowell, Richard; Jamaluddin, Saiful; Bryson, Rochelle; Delatycki, Martin B

    2010-01-01

    Friedreich's ataxia (FRDA) is an inherited ataxia with a range of progressive features including axonal degeneration of sensory nerves. The aim of this study was to investigate auditory perception in affected individuals. Fourteen subjects with genetically defined FRDA participated. Two control groups, one consisting of healthy, normally hearing individuals and another comprised of subjects with sensorineural hearing loss, were also assessed. Auditory processing was evaluated using structured tasks designed to reveal the listeners' ability to perceive temporal and spectral cues. Findings were then correlated with open-set speech understanding. Nine of 14 individuals with FRDA showed evidence of auditory processing disorder. Gap and amplitude modulation detection levels in these subjects were significantly elevated, indicating impaired encoding of rapid signal changes. Electrophysiologic findings (auditory brainstem response, ABR) also reflected disrupted neural activity. Speech understanding was significantly affected in these listeners and the degree of disruption was related to temporal processing ability. Speech analyses indicated that timing cues (notably consonant voice onset time and vowel duration) were most affected. The results suggest that auditory pathway abnormality is a relatively common consequence of FRDA. Regular auditory evaluation should therefore be part of the management regime for all affected individuals. This assessment should include both ABR testing, which can provide insights into the degree to which auditory neural activity is disrupted, and some functional measure of hearing capacity such as speech perception assessment, which can quantify the disorder and provide a basis for intervention. Copyright 2009 S. Karger AG, Basel.

  20. Representation of Reward Feedback in Primate Auditory Cortex

    Directory of Open Access Journals (Sweden)

    Michael eBrosch

    2011-02-01

    Full Text Available It is well established that auditory cortex is plastic on different time scales and that this plasticity is driven by the reinforcement that is used to motivate subjects to learn or to perform an auditory task. Motivated by these findings, we study in detail properties of neuronal firing in auditory cortex that is related to reward feedback. We recorded from the auditory cortex of two monkeys while they were performing an auditory categorization task. Monkeys listened to a sequence of tones and had to signal when the frequency of adjacent tones stepped in downward direction, irrespective of the tone frequency and step size. Correct identifications were rewarded with either a large or a small amount of water. The size of reward depended on the monkeys' performance in the previous trial: it was large after a correct trial and small after an incorrect trial. The rewards served to maintain task performance. During task performance we found three successive periods of neuronal firing in auditory cortex that reflected (1 the reward expectancy for each trial, (2 the reward size received and (3 the mismatch between the expected and delivered reward. These results, together with control experiments suggest that auditory cortex receives reward feedback that could be used to adapt auditory cortex to task requirements. Additionally, the results presented here extend previous observations of non-auditory roles of auditory cortex and shows that auditory cortex is even more cognitively influenced than lately recognized.

  1. Trigger delay compensation of beam synchronous sampling

    International Nuclear Information System (INIS)

    Steimel, J.

    1996-05-01

    One of the problems of providing beam feedback in a large accelerator is the lack of beam synchronous trigger signals far from the RF signal source. IF single bucket resolutions are required, a cable extending from the RF source to the other side of the accelerator will not provide a synchronous signal if the RF frequency changes significantly with respect to the cable delay. This paper offers a solution to this problem by locking to the RF, at the remote location, using a digital phase locked loop. Then, the digitized frequency value is used to calculate the phase shift required to remain synchronized to the beam. Results are shown for phase lock to the Fermilab Main Ring RF. 1 ref., 4 figs

  2. Perisaccadic localization of auditory stimuli.

    Science.gov (United States)

    Klingenhoefer, Steffen; Bremmer, Frank

    2009-09-01

    Interaction with the outside world requires the knowledge about where objects are with respect to one's own body. Such spatial information is represented in various topographic maps in different sensory systems. From a computational point of view, however, a single, modality-invariant map of the incoming sensory signals appears to be a more efficient strategy for spatial representations. If such a single supra-modal map existed and were used for perceptual purposes, localization characteristics should be similar across modalities. Previous studies had shown mislocalization of brief visual stimuli presented in the temporal vicinity of saccadic eye-movements. Here, we tested, if such mislocalizations could also be found for auditory stimuli. We presented brief noise bursts before, during, and after visually guided saccades. Indeed, we found localization errors for these auditory stimuli. The spatio-temporal pattern of this mislocalization, however, clearly differed from the one found for visual stimuli. The spatial error also depended on the exact type of eye-movement (visually guided vs. memory guided saccades). Finally, results obtained in fixational control paradigms under different conditions suggest that auditory localization can be strongly influenced by both static and dynamic visual stimuli. Visual localization on the other hand is not influenced by distracting visual stimuli but can be inaccurate in the temporal vicinity of eye-movements. Taken together, our results argue against a single, modality-independent spatial representation of sensory signals.

  3. Representation of acoustic signals in the eighth nerve of the Tokay gecko: I. Pure tones.

    Science.gov (United States)

    Sams-Dodd, F; Capranica, R R

    1994-06-01

    A systematic study of the encoding properties of 146 auditory nerve fibers in the Tokay gecko (Gekko gecko, L) was conducted with respect to pure tones and two-tone rate suppression. Our aim was a comprehensive understanding of the peripheral encoding of simple tonal stimuli and their representation by temporal synchronization and spike rate codes as a prelude to subsequent studies of more complex signals. Auditory nerve fibers in the Tokay gecko have asymmetrical, V-shaped excitatory tuning curves with best excitatory frequencies that range from 200-5100 Hz and thresholds between 4-35 dB SPL. A low-frequency excitatory 'tail' extends far into the low-frequency range and two-tone suppression is present only on the high frequency side of the tuning curve. The response properties to pure tones at different loci within a tuning curve can differ greatly, due to evident interactions between the representations of temporal, spectral and intensity stimulus features. For frequencies below 1250 Hz, pure tones are encoded by both temporal synchronization and spike rate codes, whereas above this frequency a fiber's ability to encode the waveform periodicity is lost and only a rate code predominates. These complimentary representations within a tuning curve raise fundamental issues which need to be addressed in interpreting how more complex, bioacoustic communication signals are represented in the peripheral and central auditory system. And since auditory nerve fibers in the Tokay gecko exhibit tonal sensitivity, selective frequency tuning, and iso-intensity and iso-frequency contours that seem comparable to similar measures in birds and mammals, these issues likely apply to most higher vertebrates in general. The simpler wiring diagram of the reptilian auditory system, coupled with the Tokay gecko's remarkable vocalizations, make this animal a good evolutionary model in which to experimentally explore the encoding of more complex sounds of communicative significance.

  4. Absence of both auditory evoked potentials and auditory percepts dependent on timing cues.

    Science.gov (United States)

    Starr, A; McPherson, D; Patterson, J; Don, M; Luxford, W; Shannon, R; Sininger, Y; Tonakawa, L; Waring, M

    1991-06-01

    An 11-yr-old girl had an absence of sensory components of auditory evoked potentials (brainstem, middle and long-latency) to click and tone burst stimuli that she could clearly hear. Psychoacoustic tests revealed a marked impairment of those auditory perceptions dependent on temporal cues, that is, lateralization of binaural clicks, change of binaural masked threshold with changes in signal phase, binaural beats, detection of paired monaural clicks, monaural detection of a silent gap in a sound, and monaural threshold elevation for short duration tones. In contrast, auditory functions reflecting intensity or frequency discriminations (difference limens) were only minimally impaired. Pure tone audiometry showed a moderate (50 dB) bilateral hearing loss with a disproportionate severe loss of word intelligibility. Those auditory evoked potentials that were preserved included (1) cochlear microphonics reflecting hair cell activity; (2) cortical sustained potentials reflecting processing of slowly changing signals; and (3) long-latency cognitive components (P300, processing negativity) reflecting endogenous auditory cognitive processes. Both the evoked potential and perceptual deficits are attributed to changes in temporal encoding of acoustic signals perhaps occurring at the synapse between hair cell and eighth nerve dendrites. The results from this patient are discussed in relation to previously published cases with absent auditory evoked potentials and preserved hearing.

  5. Neural Entrainment to Auditory Imagery of Rhythms

    Directory of Open Access Journals (Sweden)

    Haruki Okawa

    2017-10-01

    Full Text Available A method of reconstructing perceived or imagined music by analyzing brain activity has not yet been established. As a first step toward developing such a method, we aimed to reconstruct the imagery of rhythm, which is one element of music. It has been reported that a periodic electroencephalogram (EEG response is elicited while a human imagines a binary or ternary meter on a musical beat. However, it is not clear whether or not brain activity synchronizes with fully imagined beat and meter without auditory stimuli. To investigate neural entrainment to imagined rhythm during auditory imagery of beat and meter, we recorded EEG while nine participants (eight males and one female imagined three types of rhythm without auditory stimuli but with visual timing, and then we analyzed the amplitude spectra of the EEG. We also recorded EEG while the participants only gazed at the visual timing as a control condition to confirm the visual effect. Furthermore, we derived features of the EEG using canonical correlation analysis (CCA and conducted an experiment to individually classify the three types of imagined rhythm from the EEG. The results showed that classification accuracies exceeded the chance level in all participants. These results suggest that auditory imagery of meter elicits a periodic EEG response that changes at the imagined beat and meter frequency even in the fully imagined conditions. This study represents the first step toward the realization of a method for reconstructing the imagined music from brain activity.

  6. Stochastic resonance modulates neural synchronization within and between cortical sources.

    Directory of Open Access Journals (Sweden)

    Lawrence M Ward

    Full Text Available Neural synchronization is a mechanism whereby functionally specific brain regions establish transient networks for perception, cognition, and action. Direct addition of weak noise (fast random fluctuations to various neural systems enhances synchronization through the mechanism of stochastic resonance (SR. Moreover, SR also occurs in human perception, cognition, and action. Perception, cognition, and action are closely correlated with, and may depend upon, synchronized oscillations within specialized brain networks. We tested the hypothesis that SR-mediated neural synchronization occurs within and between functionally relevant brain areas and thus could be responsible for behavioral SR. We measured the 40-Hz transient response of the human auditory cortex to brief pure tones. This response arises when the ongoing, random-phase, 40-Hz activity of a group of tuned neurons in the auditory cortex becomes synchronized in response to the onset of an above-threshold sound at its "preferred" frequency. We presented a stream of near-threshold standard sounds in various levels of added broadband noise and measured subjects' 40-Hz response to the standards in a deviant-detection paradigm using high-density EEG. We used independent component analysis and dipole fitting to locate neural sources of the 40-Hz response in bilateral auditory cortex, left posterior cingulate cortex and left superior frontal gyrus. We found that added noise enhanced the 40-Hz response in all these areas. Moreover, added noise also increased the synchronization between these regions in alpha and gamma frequency bands both during and after the 40-Hz response. Our results demonstrate neural SR in several functionally specific brain regions, including areas not traditionally thought to contribute to the auditory 40-Hz transient response. In addition, we demonstrated SR in the synchronization between these brain regions. Thus, both intra- and inter-regional synchronization of neural

  7. The human brain maintains contradictory and redundant auditory sensory predictions.

    Directory of Open Access Journals (Sweden)

    Marika Pieszek

    Full Text Available Computational and experimental research has revealed that auditory sensory predictions are derived from regularities of the current environment by using internal generative models. However, so far, what has not been addressed is how the auditory system handles situations giving rise to redundant or even contradictory predictions derived from different sources of information. To this end, we measured error signals in the event-related brain potentials (ERPs in response to violations of auditory predictions. Sounds could be predicted on the basis of overall probability, i.e., one sound was presented frequently and another sound rarely. Furthermore, each sound was predicted by an informative visual cue. Participants' task was to use the cue and to discriminate the two sounds as fast as possible. Violations of the probability based prediction (i.e., a rare sound as well as violations of the visual-auditory prediction (i.e., an incongruent sound elicited error signals in the ERPs (Mismatch Negativity [MMN] and Incongruency Response [IR]. Particular error signals were observed even in case the overall probability and the visual symbol predicted different sounds. That is, the auditory system concurrently maintains and tests contradictory predictions. Moreover, if the same sound was predicted, we observed an additive error signal (scalp potential and primary current density equaling the sum of the specific error signals. Thus, the auditory system maintains and tolerates functionally independently represented redundant and contradictory predictions. We argue that the auditory system exploits all currently active regularities in order to optimally prepare for future events.

  8. Noncoherent Symbol Synchronization Techniques

    Science.gov (United States)

    Simon, Marvin

    2005-01-01

    Traditional methods for establishing symbol synchronization (sync) in digital communication receivers assume that carrier sync has already been established, i.e., the problem is addressed at the baseband level assuming that a 'perfect' estimate of carrier phase is available. We refer to this approach as coherent symbol sync. Since, for NRZ signaling, a suppressed carrier sync loop such as an I-Q Costas loop includes integrate-and-dump (I and D) filters in its in-phase (1) and quadrature (Q) arms, the traditional approach is to first track the carrier in the absence of symbol sync information, then feed back the symbol sync estimate to these filters, and then iterate between the two to a desirable operating level In this paper, we revisit the symbol sync problem by examining methods for obtaining such sync in the absence of carrier phase information, i.e., so-called noncoherent symbol sync loops. We compare the performance of these loops with that of a well-known coherent symbol sync loop and examine the conditions under which one is preferable over the other.

  9. Attending to auditory memory.

    Science.gov (United States)

    Zimmermann, Jacqueline F; Moscovitch, Morris; Alain, Claude

    2016-06-01

    Attention to memory describes the process of attending to memory traces when the object is no longer present. It has been studied primarily for representations of visual stimuli with only few studies examining attention to sound object representations in short-term memory. Here, we review the interplay of attention and auditory memory with an emphasis on 1) attending to auditory memory in the absence of related external stimuli (i.e., reflective attention) and 2) effects of existing memory on guiding attention. Attention to auditory memory is discussed in the context of change deafness, and we argue that failures to detect changes in our auditory environments are most likely the result of a faulty comparison system of incoming and stored information. Also, objects are the primary building blocks of auditory attention, but attention can also be directed to individual features (e.g., pitch). We review short-term and long-term memory guided modulation of attention based on characteristic features, location, and/or semantic properties of auditory objects, and propose that auditory attention to memory pathways emerge after sensory memory. A neural model for auditory attention to memory is developed, which comprises two separate pathways in the parietal cortex, one involved in attention to higher-order features and the other involved in attention to sensory information. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Synchronicity and Leadership

    NARCIS (Netherlands)

    Merry, Philip

    2017-01-01

    LAY SUMMARY SYNCHRONICITY AND LEADERSHIP TILBURG PHD DISSERTATION, PHILIP MERRY World’s First PhD to Research Synchronicity And Leadership Using Grounded Theory OUT OF THE BLUE COINCIDENCES: research topic Most people have had the experience of thinking of someone and then, almost magically have

  11. Synchronization of networks

    Indian Academy of Sciences (India)

    For networks with time-varying topology we compare the synchronization properties of these networks with the corresponding time-average network. We find that if the different coupling matrices corresponding to the time-varying networks commute with each other then the stability of the synchronized state for both the ...

  12. Prediction of speech intelligibility based on an auditory preprocessing model

    DEFF Research Database (Denmark)

    Christiansen, Claus Forup Corlin; Pedersen, Michael Syskind; Dau, Torsten

    2010-01-01

    Classical speech intelligibility models, such as the speech transmission index (STI) and the speech intelligibility index (SII) are based on calculations on the physical acoustic signals. The present study predicts speech intelligibility by combining a psychoacoustically validated model of auditory...

  13. Dependence of synchronization transitions on mean field approach in two-way coupled neural system

    Science.gov (United States)

    Shi, J. C.; Luo, M.; Huang, C. S.

    2018-03-01

    This work investigates the synchronization transitions in two-way coupled neural system by mean field approach. Results show that, there exists a critical noise intensity for the synchronization transitions, i.e., above (or below) the critical noise intensity, the synchronization transitions are decreased (or hardly change) with increasing the noise intensity. Meanwhile, the heterogeneity effect plays a negative role for the synchronization transitions, and above critical coupling strength, the heterogeneity effect on synchronization transitions can be negligible. Furthermore, when an external signal is introduced into the coupled system, the novel frequency-induced and amplitude-induced synchronization transitions are found, and there exist an optimal frequency and an optimal amplitude of external signal which makes the system to display the best synchronization transitions. In particular, it is observed that the synchronization transitions can not be further affected above critical frequency of external signal.

  14. Facilitated auditory detection for speech sounds

    Directory of Open Access Journals (Sweden)

    Carine eSignoret

    2011-07-01

    Full Text Available If it is well known that knowledge facilitates higher cognitive functions, such as visual and auditory word recognition, little is known about the influence of knowledge on detection, particularly in the auditory modality. Our study tested the influence of phonological and lexical knowledge on auditory detection. Words, pseudo words and complex non phonological sounds, energetically matched as closely as possible, were presented at a range of presentation levels from sub threshold to clearly audible. The participants performed a detection task (Experiments 1 and 2 that was followed by a two alternative forced choice recognition task in Experiment 2. The results of this second task in Experiment 2 suggest a correct recognition of words in the absence of detection with a subjective threshold approach. In the detection task of both experiments, phonological stimuli (words and pseudo words were better detected than non phonological stimuli (complex sounds, presented close to the auditory threshold. This finding suggests an advantage of speech for signal detection. An additional advantage of words over pseudo words was observed in Experiment 2, suggesting that lexical knowledge could also improve auditory detection when listeners had to recognize the stimulus in a subsequent task. Two simulations of detection performance performed on the sound signals confirmed that the advantage of speech over non speech processing could not be attributed to energetic differences in the stimuli.

  15. Lag synchronization of hyperchaos with application to secure communications

    International Nuclear Information System (INIS)

    Li Chuandong; Liao Xiaofeng; Wong Kwokwo

    2005-01-01

    In this paper, hyperchaotic lag synchronization is restated as a nonlinear and lag-in-time observer design issue. This approach leads to a systematic tool, which guarantees the lag synchronization of a wide class of chaotic or hyperchaotic systems via a scalar signal. By exploiting this result, we propose a hyperchaos-based cryptosystem scheme that combines the conventional cryptographic methods and the lag synchronization of chaotic circuits. The computer simulation results show that the lag synchronization scheme and the cryptosystem proposed in this paper are both feasible

  16. The auditory-evoked N2 and P3 components in the stop-signal task: indices of inhibition, response-conflict or error-detection?

    Science.gov (United States)

    Dimoska, Aneta; Johnstone, Stuart J; Barry, Robert J

    2006-11-01

    The N2 and P3 components have been separately associated with response inhibition in the stop-signal task, and more recently, the N2 has been implicated in the detection of response-conflict. To isolate response inhibition activity from early sensory processing, the present study compared processing of the stop-signal with that of a task-irrelevant tone, which subjects were instructed to ignore. Stop-signals elicited a larger N2 on failed-stop trials and a larger P3 on successful-stop trials, relative to ignore-signal trials, likely reflecting activity related to failed and successful stopping, respectively. ERPs between fast and slow reaction-time (RT) groups were also examined as it was hypothesised that greater inhibitory activation to stop faster responses would manifest in the component reflecting this process. Successful-stop P3 showed the anticipated effect (globally larger amplitude in the fast than slow RT group), supporting its association with the stopping of an ongoing response. In contrast, N2 was larger in the slow than fast RT group, and in contrast to the predictions of the response-conflict hypothesis, successful-stop N2 and the response-locked error-negativity (Ne) differed in scalp distribution. These findings indicate that the successful-stop N2 may be better explained as a deliberate form of response control or selection, which the slow RT group employed as a means of increasing the likelihood of a successful-stop. Finally, a comparison of stimulus and response-locked ERPs revealed that the failed-stop N2 and P3 appeared to reflect error-related activity, best observed in the response-locked Ne and error-positivity (Pe). Together these findings indicate that the successful-stop N2 and P3 reflect functionally distinct aspects of response control that are dependent upon performance strategies, while failed-stop N2 and P3 reflect error-related activity.

  17. Continuity of visual and auditory rhythms influences sensorimotor coordination.

    Directory of Open Access Journals (Sweden)

    Manuel Varlet

    Full Text Available People often coordinate their movement with visual and auditory environmental rhythms. Previous research showed better performances when coordinating with auditory compared to visual stimuli, and with bimodal compared to unimodal stimuli. However, these results have been demonstrated with discrete rhythms and it is possible that such effects depend on the continuity of the stimulus rhythms (i.e., whether they are discrete or continuous. The aim of the current study was to investigate the influence of the continuity of visual and auditory rhythms on sensorimotor coordination. We examined the dynamics of synchronized oscillations of a wrist pendulum with auditory and visual rhythms at different frequencies, which were either unimodal or bimodal and discrete or continuous. Specifically, the stimuli used were a light flash, a fading light, a short tone and a frequency-modulated tone. The results demonstrate that the continuity of the stimulus rhythms strongly influences visual and auditory motor coordination. Participants' movement led continuous stimuli and followed discrete stimuli. Asymmetries between the half-cycles of the movement in term of duration and nonlinearity of the trajectory occurred with slower discrete rhythms. Furthermore, the results show that the differences of performance between visual and auditory modalities depend on the continuity of the stimulus rhythms as indicated by movements closer to the instructed coordination for the auditory modality when coordinating with discrete stimuli. The results also indicate that visual and auditory rhythms are integrated together in order to better coordinate irrespective of their continuity, as indicated by less variable coordination closer to the instructed pattern. Generally, the findings have important implications for understanding how we coordinate our movements with visual and auditory environmental rhythms in everyday life.

  18. Asynchronized synchronous machines

    CERN Document Server

    Botvinnik, M M

    1964-01-01

    Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids” of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv

  19. Detection of generalized synchronization using echo state networks

    Science.gov (United States)

    Ibáñez-Soria, D.; Garcia-Ojalvo, J.; Soria-Frisch, A.; Ruffini, G.

    2018-03-01

    Generalized synchronization between coupled dynamical systems is a phenomenon of relevance in applications that range from secure communications to physiological modelling. Here, we test the capabilities of reservoir computing and, in particular, echo state networks for the detection of generalized synchronization. A nonlinear dynamical system consisting of two coupled Rössler chaotic attractors is used to generate temporal series consisting of time-locked generalized synchronized sequences interleaved with unsynchronized ones. Correctly tuned, echo state networks are able to efficiently discriminate between unsynchronized and synchronized sequences even in the presence of relatively high levels of noise. Compared to other state-of-the-art techniques of synchronization detection, the online capabilities of the proposed Echo State Network based methodology make it a promising choice for real-time applications aiming to monitor dynamical synchronization changes in continuous signals.

  20. Auditory-motor learning influences auditory memory for music.

    Science.gov (United States)

    Brown, Rachel M; Palmer, Caroline

    2012-05-01

    In two experiments, we investigated how auditory-motor learning influences performers' memory for music. Skilled pianists learned novel melodies in four conditions: auditory only (listening), motor only (performing without sound), strongly coupled auditory-motor (normal performance), and weakly coupled auditory-motor (performing along with auditory recordings). Pianists' recognition of the learned melodies was better following auditory-only or auditory-motor (weakly coupled and strongly coupled) learning than following motor-only learning, and better following strongly coupled auditory-motor learning than following auditory-only learning. Auditory and motor imagery abilities modulated the learning effects: Pianists with high auditory imagery scores had better recognition following motor-only learning, suggesting that auditory imagery compensated for missing auditory feedback at the learning stage. Experiment 2 replicated the findings of Experiment 1 with melodies that contained greater variation in acoustic features. Melodies that were slower and less variable in tempo and intensity were remembered better following weakly coupled auditory-motor learning. These findings suggest that motor learning can aid performers' auditory recognition of music beyond auditory learning alone, and that motor learning is influenced by individual abilities in mental imagery and by variation in acoustic features.

  1. Auditory Discrimination and Auditory Memory as Predictors of Academic Success.

    Science.gov (United States)

    Warnock, Mairi; Boss, Marvin W.

    1987-01-01

    Eighty fourth-graders enrolled in an English/French bilingual program in Canada were administered an auditory skills battery of six tests to measure auditory discrimination and short-term auditory memory. It was concluded that a relationship exists between certain auditory perceptual abilities and school achievement independent of cognitive…

  2. Synchronization in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

    2007-12-12

    Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

  3. Grid synchronization structure for wind converters under grid fault conditions

    OpenAIRE

    Garcia, Jose Ignacio; Candela García, José Ignacio; Luna Alloza, Álvaro; Catalan, Pedro

    2016-01-01

    This paper presents a grid synchronization structure for three-phase electric power systems based on the use of a filtered quadrature signal generator (FQSG) and a phase-locked loop (PLL) structure, named Adaptive Vector Grid Synchronization system (AVGS). This system estimates the magnitude, frequency and phase of a signal, specially three-phase voltages and currents, and allows fast and accurate detection of the symmetrical components meet with the transient operating requirements imposed b...

  4. Design of Short Synchronization Codes for Use in Future GNSS System

    Directory of Open Access Journals (Sweden)

    Surendran K. Shanmugam

    2008-01-01

    The modernization efforts include numerous signal structure innovations to ensure better performances over legacy GNSS system. The adoption of secondary short synchronization codes is one among these innovations that play an important role in spectral separation, bit synchronization, and narrowband interference protection. In this paper, we present a short synchronization code design based on the optimization of judiciously selected performance criteria. The new synchronization codes were obtained for lengths up to 30 bits through exhaustive search and are characterized by optimal periodic correlation. More importantly, the presence of better synchronization codes over standardized GPS and Galileo codes corroborates the benefits and the need for short synchronization code design.

  5. Different Auditory Feedback Control for Echolocation and Communication in Horseshoe Bats

    OpenAIRE

    Liu, Ying; Feng, Jiang; Metzner, Walter

    2013-01-01

    Auditory feedback from the animal's own voice is essential during bat echolocation: to optimize signal detection, bats continuously adjust various call parameters in response to changing echo signals. Auditory feedback seems also necessary for controlling many bat communication calls, although it remains unclear how auditory feedback control differs in echolocation and communication. We tackled this question by analyzing echolocation and communication in greater horseshoe bats, whose echoloca...

  6. Controlled Limiter in the Synchronous Detection Circuit

    Directory of Open Access Journals (Sweden)

    Yauheni Bialetski

    2017-07-01

    Full Text Available This variant of construction of the electrical circuit is aimed at reducing the effects of impulse noise. The measuring channels of the primary transducers are subject to interference of various types. In the case of a small ratio between a useful signal and noise level, synchronous detection is used. Impulse noise leaves a big mark even after using synchronous detection. To improve the performance of such measuring devices, it is proposed to use a controlled amplitude limiter at the input. Comparative analysis of solutions with controlled limiters is carried out in the article and conditions for its optimal operation are determined.

  7. Carrier and symbol synchronization system performance study

    Science.gov (United States)

    Lindsey, W. C.

    1976-01-01

    Results pertinent to predicting the performance of convolutionally encoded binary phase-shift keyed communication links were presented. The details of the development are provided in four sections. These sections are concerned with developing the bit error probability performance degradations due to PN despreading by a time-shared delay locked loop, the Costas demodulation process, symbol synchronization effects and cycle slipping phenomena in the Costas loop. In addition, Costas cycle slipping probabilities are studied as functions of Doppler count time and signal-to-noise conditions. The effect of cycle slipping in the symbol synchronizer is also studied as a function of channel Doppler and other frequency uncertainties.

  8. Inter-subject synchronization of brain responses during natural music listening.

    Science.gov (United States)

    Abrams, Daniel A; Ryali, Srikanth; Chen, Tianwen; Chordia, Parag; Khouzam, Amirah; Levitin, Daniel J; Menon, Vinod

    2013-05-01

    Music is a cultural universal and a rich part of the human experience. However, little is known about common brain systems that support the processing and integration of extended, naturalistic 'real-world' music stimuli. We examined this question by presenting extended excerpts of symphonic music, and two pseudomusical stimuli in which the temporal and spectral structure of the Natural Music condition were disrupted, to non-musician participants undergoing functional brain imaging and analysing synchronized spatiotemporal activity patterns between listeners. We found that music synchronizes brain responses across listeners in bilateral auditory midbrain and thalamus, primary auditory and auditory association cortex, right-lateralized structures in frontal and parietal cortex, and motor planning regions of the brain. These effects were greater for natural music compared to the pseudo-musical control conditions. Remarkably, inter-subject synchronization in the inferior colliculus and medial geniculate nucleus was also greater for the natural music condition, indicating that synchronization at these early stages of auditory processing is not simply driven by spectro-temporal features of the stimulus. Increased synchronization during music listening was also evident in a right-hemisphere fronto-parietal attention network and bilateral cortical regions involved in motor planning. While these brain structures have previously been implicated in various aspects of musical processing, our results are the first to show that these regions track structural elements of a musical stimulus over extended time periods lasting minutes. Our results show that a hierarchical distributed network is synchronized between individuals during the processing of extended musical sequences, and provide new insight into the temporal integration of complex and biologically salient auditory sequences. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  9. Inter-subject synchronization of brain responses during natural music listening

    Science.gov (United States)

    Abrams, Daniel A.; Ryali, Srikanth; Chen, Tianwen; Chordia, Parag; Khouzam, Amirah; Levitin, Daniel J.; Menon, Vinod

    2015-01-01

    Music is a cultural universal and a rich part of the human experience. However, little is known about common brain systems that support the processing and integration of extended, naturalistic ‘real-world’ music stimuli. We examined this question by presenting extended excerpts of symphonic music, and two pseudomusical stimuli in which the temporal and spectral structure of the Natural Music condition were disrupted, to non-musician participants undergoing functional brain imaging and analysing synchronized spatiotemporal activity patterns between listeners. We found that music synchronizes brain responses across listeners in bilateral auditory midbrain and thalamus, primary auditory and auditory association cortex, right-lateralized structures in frontal and parietal cortex, and motor planning regions of the brain. These effects were greater for natural music compared to the pseudo-musical control conditions. Remarkably, inter-subject synchronization in the inferior colliculus and medial geniculate nucleus was also greater for the natural music condition, indicating that synchronization at these early stages of auditory processing is not simply driven by spectro-temporal features of the stimulus. Increased synchronization during music listening was also evident in a right-hemisphere fronto-parietal attention network and bilateral cortical regions involved in motor planning. While these brain structures have previously been implicated in various aspects of musical processing, our results are the first to show that these regions track structural elements of a musical stimulus over extended time periods lasting minutes. Our results show that a hierarchical distributed network is synchronized between individuals during the processing of extended musical sequences, and provide new insight into the temporal integration of complex and biologically salient auditory sequences. PMID:23578016

  10. Synchronization of Discrete-Time Chaotic Systems in Bandlimited Channels

    Directory of Open Access Journals (Sweden)

    Marcio Eisencraft

    2009-01-01

    Full Text Available Over the last couple of decades, many methods for synchronizing chaotic systems have been proposed with communications applications in view. Yet their performance has proved disappointing in face of the nonideal character of usual channels linking transmitter and receiver, that is, due to both noise and signal propagation distortion. Here we consider a discrete-time master-slave system that synchronizes despite channel bandwidth limitations and an allied communication system. Synchronization is achieved introducing a digital filter that limits the spectral content of the feedback loop responsible for producing the transmitted signal.

  11. Effects of wi-fi signals on the p300 component of event-related potentials during an auditory hayling task.

    Science.gov (United States)

    Papageorgiou, Charalabos C; Hountala, Chrissanthi D; Maganioti, Argiro E; Kyprianou, Miltiades A; Rabavilas, Andreas D; Papadimitriou, George N; Capsalis, Christos N

    2011-06-01

    The P300 component of event-related potentials (ERPs) is believed to index attention and working memory (WM) operation of the brain. The present study focused on the possible gender-related effects of Wi-Fi (Wireless Fidelity) electromagnetic fields (EMF) on these processes. Fifteen male and fifteen female subjects, matched for age and education level, were investigated while performing a modified version of the Hayling Sentence Completion test adjusted to induce WM. ERPs were recorded at 30 scalp electrodes, both without and with the exposure to a Wi-Fi signal. P300 amplitude values at 18 electrodes were found to be significantly lower in the response inhibition condition than in the response initiation and baseline conditions. Independent of the above effect, within the response inhibition condition there was also a significant gender X radiation interaction effect manifested at 15 leads by decreased P300 amplitudes of males in comparison to female subjects only at the presence of EMF. In conclusion, the present findings suggest that Wi-Fi exposure may exert gender-related alterations on neural activity associated with the amount of attentional resources engaged during a linguistic test adjusted to induce WM.

  12. Auditory Integration Training

    Directory of Open Access Journals (Sweden)

    Zahra Jafari

    2002-07-01

    Full Text Available Auditory integration training (AIT is a hearing enhancement training process for sensory input anomalies found in individuals with autism, attention deficit hyperactive disorder, dyslexia, hyperactivity, learning disability, language impairments, pervasive developmental disorder, central auditory processing disorder, attention deficit disorder, depressin, and hyperacute hearing. AIT, recently introduced in the United States, and has received much notice of late following the release of The Sound of a Moracle, by Annabel Stehli. In her book, Mrs. Stehli describes before and after auditory integration training experiences with her daughter, who was diagnosed at age four as having autism.

  13. Review: Auditory Integration Training

    Directory of Open Access Journals (Sweden)

    Zahra Ja'fari

    2003-01-01

    Full Text Available Auditory integration training (AIT is a hearing enhancement training process for sensory input anomalies found in individuals with autism, attention deficit hyperactive disorder, dyslexia, hyperactivity, learning disability, language impairments, pervasive developmental disorder, central auditory processing disorder, attention deficit disorder, depression, and hyper acute hearing. AIT, recently introduced in the United States, and has received much notice of late following the release of the sound of a miracle, by Annabel Stehli. In her book, Mrs. Stehli describes before and after auditory integration training experiences with her daughter, who was diagnosed at age four as having autism.

  14. Whispering - The hidden side of auditory communication.

    Science.gov (United States)

    Frühholz, Sascha; Trost, Wiebke; Grandjean, Didier

    2016-11-15

    Whispering is a unique expression mode that is specific to auditory communication. Individuals switch their vocalization mode to whispering especially when affected by inner emotions in certain social contexts, such as in intimate relationships or intimidating social interactions. Although this context-dependent whispering is adaptive, whispered voices are acoustically far less rich than phonated voices and thus impose higher hearing and neural auditory decoding demands for recognizing their socio-affective value by listeners. The neural dynamics underlying this recognition especially from whispered voices are largely unknown. Here we show that whispered voices in humans are considerably impoverished as quantified by an entropy measure of spectral acoustic information, and this missing information needs large-scale neural compensation in terms of auditory and cognitive processing. Notably, recognizing the socio-affective information from voices was slightly more difficult from whispered voices, probably based on missing tonal information. While phonated voices elicited extended activity in auditory regions for decoding of relevant tonal and time information and the valence of voices, whispered voices elicited activity in a complex auditory-frontal brain network. Our data suggest that a large-scale multidirectional brain network compensates for the impoverished sound quality of socially meaningful environmental signals to support their accurate recognition and valence attribution. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Auditory memory for temporal characteristics of sound.

    Science.gov (United States)

    Zokoll, Melanie A; Klump, Georg M; Langemann, Ulrike

    2008-05-01

    This study evaluates auditory memory for variations in the rate of sinusoidal amplitude modulation (SAM) of noise bursts in the European starling (Sturnus vulgaris). To estimate the extent of the starling's auditory short-term memory store, a delayed non-matching-to-sample paradigm was applied. The birds were trained to discriminate between a series of identical "sample stimuli" and a single "test stimulus". The birds classified SAM rates of sample and test stimuli as being either the same or different. Memory performance of the birds was measured as the percentage of correct classifications. Auditory memory persistence time was estimated as a function of the delay between sample and test stimuli. Memory performance was significantly affected by the delay between sample and test and by the number of sample stimuli presented before the test stimulus, but was not affected by the difference in SAM rate between sample and test stimuli. The individuals' auditory memory persistence times varied between 2 and 13 s. The starlings' auditory memory persistence in the present study for signals varying in the temporal domain was significantly shorter compared to that of a previous study (Zokoll et al. in J Acoust Soc Am 121:2842, 2007) applying tonal stimuli varying in the spectral domain.

  16. Synchronization controller design of two coupling permanent magnet synchronous motors system with nonlinear constraints.

    Science.gov (United States)

    Deng, Zhenhua; Shang, Jing; Nian, Xiaohong

    2015-11-01

    In this paper, two coupling permanent magnet synchronous motors system with nonlinear constraints is studied. First of all, the mathematical model of the system is established according to the engineering practices, in which the dynamic model of motor and the nonlinear coupling effect between two motors are considered. In order to keep the two motors synchronization, a synchronization controller based on load observer is designed via cross-coupling idea and interval matrix. Moreover, speed, position and current signals of two motor all are taken as self-feedback signal as well as cross-feedback signal in the proposed controller, which is conducive to improving the dynamical performance and the synchronization performance of the system. The proposed control strategy is verified by simulation via Matlab/Simulink program. The simulation results show that the proposed control method has a better control performance, especially synchronization performance, than that of the conventional PI controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Sensorimotor synchronization with different metrical levels of point-light dance movements

    Directory of Open Access Journals (Sweden)

    Yi-Huang eSu

    2016-04-01

    Full Text Available Rhythm perception and synchronization have been extensively investigated in the auditory domain, as they underlie means of human communication such as music and speech. Although recent studies suggest comparable mechanisms for synchronizing with periodically moving visual objects, the extent to which it applies to ecologically relevant information, such as the rhythm of complex biological motion, remains unknown. The present study addressed this issue by linking rhythm of music and dance in the framework of action-perception coupling. As a previous study showed that observers perceived multiple metrical periodicities in dance movements that embodied this structure, the present study examined whether sensorimotor synchronization (SMS to dance movements resembles what is known of auditory SMS. Participants watched a point-light figure performing two basic steps of Swing dance cyclically, in which the trunk bounced at every beat and the limbs moved at every second beat, forming two metrical periodicities. Participants tapped synchronously to the bounce of the trunk with or without the limbs moving in the stimuli (Experiment 1, or tapped synchronously to the leg movements with or without the trunk bouncing simultaneously (Experiment 2. Results showed that, while synchronization with the bounce (lower-level pulse was not influenced by the presence or absence of limb movements (metrical accent, synchronization with the legs (beat was improved by the presence of the bounce (metrical subdivision across different movement types. The latter finding parallels the subdivision benefit often demonstrated in auditory tasks, suggesting common sensorimotor mechanisms for visual rhythms in dance and auditory rhythms in music.

  18. Sensorimotor Synchronization with Different Metrical Levels of Point-Light Dance Movements

    Science.gov (United States)

    Su, Yi-Huang

    2016-01-01

    Rhythm perception and synchronization have been extensively investigated in the auditory domain, as they underlie means of human communication such as music and speech. Although recent studies suggest comparable mechanisms for synchronizing with periodically moving visual objects, the extent to which it applies to ecologically relevant information, such as the rhythm of complex biological motion, remains unknown. The present study addressed this issue by linking rhythm of music and dance in the framework of action-perception coupling. As a previous study showed that observers perceived multiple metrical periodicities in dance movements that embodied this structure, the present study examined whether sensorimotor synchronization (SMS) to dance movements resembles what is known of auditory SMS. Participants watched a point-light figure performing two basic steps of Swing dance cyclically, in which the trunk bounced at every beat and the limbs moved at every second beat, forming two metrical periodicities. Participants tapped synchronously to the bounce of the trunk with or without the limbs moving in the stimuli (Experiment 1), or tapped synchronously to the leg movements with or without the trunk bouncing simultaneously (Experiment 2). Results showed that, while synchronization with the bounce (lower-level pulse) was not influenced by the presence or absence of limb movements (metrical accent), synchronization with the legs (beat) was improved by the presence of the bounce (metrical subdivision) across different movement types. The latter finding parallels the “subdivision benefit” often demonstrated in auditory tasks, suggesting common sensorimotor mechanisms for visual rhythms in dance and auditory rhythms in music. PMID:27199709

  19. Temporal envelope processing in the human auditory cortex: response and interconnections of auditory cortical areas.

    Science.gov (United States)

    Gourévitch, Boris; Le Bouquin Jeannès, Régine; Faucon, Gérard; Liégeois-Chauvel, Catherine

    2008-03-01

    Temporal envelope processing in the human auditory cortex has an important role in language analysis. In this paper, depth recordings of local field potentials in response to amplitude modulated white noises were used to design maps of activation in primary, secondary and associative auditory areas and to study the propagation of the cortical activity between them. The comparison of activations between auditory areas was based on a signal-to-noise ratio associated with the response to amplitude modulation (AM). The functional connectivity between cortical areas was quantified by the directed coherence (DCOH) applied to auditory evoked potentials. This study shows the following reproducible results on twenty subjects: (1) the primary auditory cortex (PAC), the secondary cortices (secondary auditory cortex (SAC) and planum temporale (PT)), the insular gyrus, the Brodmann area (BA) 22 and the posterior part of T1 gyrus (T1Post) respond to AM in both hemispheres. (2) A stronger response to AM was observed in SAC and T1Post of the left hemisphere independent of the modulation frequency (MF), and in the left BA22 for MFs 8 and 16Hz, compared to those in the right. (3) The activation and propagation features emphasized at least four different types of temporal processing. (4) A sequential activation of PAC, SAC and BA22 areas was clearly visible at all MFs, while other auditory areas may be more involved in parallel processing upon a stream originating from primary auditory area, which thus acts as a distribution hub. These results suggest that different psychological information is carried by the temporal envelope of sounds relative to the rate of amplitude modulation.

  20. Auditory Spatial Layout

    Science.gov (United States)

    Wightman, Frederic L.; Jenison, Rick

    1995-01-01

    All auditory sensory information is packaged in a pair of acoustical pressure waveforms, one at each ear. While there is obvious structure in these waveforms, that structure (temporal and spectral patterns) bears no simple relationship to the structure of the environmental objects that produced them. The properties of auditory objects and their layout in space must be derived completely from higher level processing of the peripheral input. This chapter begins with a discussion of the peculiarities of acoustical stimuli and how they are received by the human auditory system. A distinction is made between the ambient sound field and the effective stimulus to differentiate the perceptual distinctions among various simple classes of sound sources (ambient field) from the known perceptual consequences of the linear transformations of the sound wave from source to receiver (effective stimulus). Next, the definition of an auditory object is dealt with, specifically the question of how the various components of a sound stream become segregated into distinct auditory objects. The remainder of the chapter focuses on issues related to the spatial layout of auditory objects, both stationary and moving.

  1. Shaping the aging brain: Role of auditory input patterns in the emergence of auditory cortical impairments

    Directory of Open Access Journals (Sweden)

    Brishna Soraya Kamal

    2013-09-01

    Full Text Available Age-related impairments in the primary auditory cortex (A1 include poor tuning selectivity, neural desynchronization and degraded responses to low-probability sounds. These changes have been largely attributed to reduced inhibition in the aged brain, and are thought to contribute to substantial hearing impairment in both humans and animals. Since many of these changes can be partially reversed with auditory training, it has been speculated that they might not be purely degenerative, but might rather represent negative plastic adjustments to noisy or distorted auditory signals reaching the brain. To test this hypothesis, we examined the impact of exposing young adult rats to 8 weeks of low-grade broadband noise on several aspects of A1 function and structure. We then characterized the same A1 elements in aging rats for comparison. We found that the impact of noise exposure on A1 tuning selectivity, temporal processing of auditory signal and responses to oddball tones was almost indistinguishable from the effect of natural aging. Moreover, noise exposure resulted in a reduction in the population of parvalbumin inhibitory interneurons and cortical myelin as previously documented in the aged group. Most of these changes reversed after returning the rats to a quiet environment. These results support the hypothesis that age-related changes in A1 have a strong activity-dependent component and indicate that the presence or absence of clear auditory input patterns might be a key factor in sustaining adult A1 function.

  2. Integration of Visual Information in Auditory Cortex Promotes Auditory Scene Analysis through Multisensory Binding.

    Science.gov (United States)

    Atilgan, Huriye; Town, Stephen M; Wood, Katherine C; Jones, Gareth P; Maddox, Ross K; Lee, Adrian K C; Bizley, Jennifer K

    2018-02-07

    How and where in the brain audio-visual signals are bound to create multimodal objects remains unknown. One hypothesis is that temporal coherence between dynamic multisensory signals provides a mechanism for binding stimulus features across sensory modalities. Here, we report that when the luminance of a visual stimulus is temporally coherent with the amplitude fluctuations of one sound in a mixture, the representation of that sound is enhanced in auditory cortex. Critically, this enhancement extends to include both binding and non-binding features of the sound. We demonstrate that visual information conveyed from visual cortex via the phase of the local field potential is combined with auditory information within auditory cortex. These data provide evidence that early cross-sensory binding provides a bottom-up mechanism for the formation of cross-sensory objects and that one role for multisensory binding in auditory cortex is to support auditory scene analysis. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Neural Entrainment and Sensorimotor Synchronization to the Beat in Children with Developmental Dyslexia: An EEG Study

    Directory of Open Access Journals (Sweden)

    Lincoln J. Colling

    2017-07-01

    Full Text Available Tapping in time to a metronome beat (hereafter beat synchronization shows considerable variability in child populations, and individual differences in beat synchronization are reliably related to reading development. Children with developmental dyslexia show impairments in beat synchronization. These impairments may reflect deficiencies in auditory perception of the beat which in turn affect auditory-motor mapping, or may reflect an independent motor deficit. Here, we used a new methodology in EEG based on measuring beat-related steady-state evoked potentials (SS-EPs, Nozaradan et al., 2015 in an attempt to disentangle neural sensory and motor contributions to behavioral beat synchronization in children with dyslexia. Children tapped with both their left and right hands to every second beat of a metronome pulse delivered at 2.4 Hz, or listened passively to the beat. Analyses of preferred phase in EEG showed that the children with dyslexia had a significantly different preferred phase compared to control children in all conditions. Regarding SS-EPs, the groups differed significantly for the passive Auditory listening condition at 2.4 Hz, and showed a trend toward a difference in the Right hand tapping condition at 3.6 Hz (sensorimotor integration measure. The data suggest that neural rhythmic entrainment is atypical in children with dyslexia for both an auditory beat and during sensorimotor coupling (tapping. The data are relevant to a growing literature suggesting that rhythm-based interventions may help language processing in children with developmental disorders of language learning.

  4. Synchronizing weighted automata

    Directory of Open Access Journals (Sweden)

    Szabolcs Iván

    2014-05-01

    Full Text Available We introduce two generalizations of synchronizability to automata with transitions weighted in an arbitrary semiring K=(K,+,*,0,1. (or equivalently, to finite sets of matrices in K^nxn. Let us call a matrix A location-synchronizing if there exists a column in A consisting of nonzero entries such that all the other columns of A are filled by zeros. If additionally all the entries of this designated column are the same, we call A synchronizing. Note that these notions coincide for stochastic matrices and also in the Boolean semiring. A set M of matrices in K^nxn is called (location-synchronizing if M generates a matrix subsemigroup containing a (location-synchronizing matrix. The K-(location-synchronizability problem is the following: given a finite set M of nxn matrices with entries in K, is it (location-synchronizing? Both problems are PSPACE-hard for any nontrivial semiring. We give sufficient conditions for the semiring K when the problems are PSPACE-complete and show several undecidability results as well, e.g. synchronizability is undecidable if 1 has infinite order in (K,+,0 or when the free semigroup on two generators can be embedded into (K,*,1.

  5. Auditory capture of visual motion: effects on perception and discrimination.

    Science.gov (United States)

    McCourt, Mark E; Leone, Lynnette M

    2016-09-28

    We asked whether the perceived direction of visual motion and contrast thresholds for motion discrimination are influenced by the concurrent motion of an auditory sound source. Visual motion stimuli were counterphasing Gabor patches, whose net motion energy was manipulated by adjusting the contrast of the leftward-moving and rightward-moving components. The presentation of these visual stimuli was paired with the simultaneous presentation of auditory stimuli, whose apparent motion in 3D auditory space (rightward, leftward, static, no sound) was manipulated using interaural time and intensity differences, and Doppler cues. In experiment 1, observers judged whether the Gabor visual stimulus appeared to move rightward or leftward. In experiment 2, contrast discrimination thresholds for detecting the interval containing unequal (rightward or leftward) visual motion energy were obtained under the same auditory conditions. Experiment 1 showed that the perceived direction of ambiguous visual motion is powerfully influenced by concurrent auditory motion, such that auditory motion 'captured' ambiguous visual motion. Experiment 2 showed that this interaction occurs at a sensory stage of processing as visual contrast discrimination thresholds (a criterion-free measure of sensitivity) were significantly elevated when paired with congruent auditory motion. These results suggest that auditory and visual motion signals are integrated and combined into a supramodal (audiovisual) representation of motion.

  6. Auditory evoked responses in musicians during passive vowel listening are modulated by functional connectivity between bilateral auditory-related brain regions.

    Science.gov (United States)

    Kühnis, Jürg; Elmer, Stefan; Jäncke, Lutz

    2014-12-01

    Currently, there is striking evidence showing that professional musical training can substantially alter the response properties of auditory-related cortical fields. Such plastic changes have previously been shown not only to abet the processing of musical sounds, but likewise spectral and temporal aspects of speech. Therefore, here we used the EEG technique and measured a sample of musicians and nonmusicians while the participants were passively exposed to artificial vowels in the context of an oddball paradigm. Thereby, we evaluated whether increased intracerebral functional connectivity between bilateral auditory-related brain regions may promote sensory specialization in musicians, as reflected by altered cortical N1 and P2 responses. This assumption builds on the reasoning that sensory specialization is dependent, at least in part, on the amount of synchronization between the two auditory-related cortices. Results clearly revealed that auditory-evoked N1 responses were shaped by musical expertise. In addition, in line with our reasoning musicians showed an overall increased intracerebral functional connectivity (as indexed by lagged phase synchronization) in theta, alpha, and beta bands. Finally, within-group correlative analyses indicated a relationship between intracerebral beta band connectivity and cortical N1 responses, however only within the musicians' group. Taken together, we provide first electrophysiological evidence for a relationship between musical expertise, auditory-evoked brain responses, and intracerebral functional connectivity among auditory-related brain regions.

  7. Development of a Chirp Stimulus PC-Based Auditory Brainstem Response Audiometer

    Directory of Open Access Journals (Sweden)

    Ali AL-Afsaa

    2004-05-01

    Full Text Available Hearing losses during infancy and childhood have many negative future effects and impacts on the child life and productivity. The earlier detection of hearing losses, the earlier medical intervention and then the greater benefit of remediation will be. During this research a PC-based audiometer is designed and, currently, the audiometer prototype is in its final development steps. It is based on the auditory brainstem response (ABR method. Chirp stimuli instead of traditional click stimuli will be used to invoke the ABR signal. The stimulus is designed to synchronize the hair cells movement when it spreads out over the cochlea. In addition to the available hardware utilization (PC and PCI board, the efforts confined to design and implement a hardware prototype and to develop a software package that enables the system to behave as ABR audiometer. By using such a method and chirp stimulus, it is expected to be able to detect hearing impairment (sensorineural in the first few days of the life and conduct hearing test at low frequency of stimulus. Currently, the intended chirp stimulus has been successfully generated and the implemented module is able to amplify a signal (on the order of ABR signal to a recordable level. Moreover, a NI-DAQ data acquisition board has been chosen to implement the PC-prototype interface.

  8. Biological impact of music and software-based auditory training

    Science.gov (United States)

    Kraus, Nina

    2012-01-01

    Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals – both young and old – encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in noisy environments and reading, pointing to an intersection between hearing and cognition. Musical experience, amplification, and software-based training can improve these biological signals. These findings of biological plasticity, in a variety of subject populations, relate to attention and auditory memory, and represent an integrated auditory system influenced by both sensation and cognition. Learning outcomes The reader will (1) understand that the auditory system is malleable to experience and training, (2) learn the ingredients necessary for auditory learning to successfully be applied to communication, (3) learn that the auditory brainstem response to complex sounds (cABR) is a window into the integrated auditory system, and (4) see examples of how cABR can be used to track the outcome of experience and training. PMID:22789822

  9. Optimistic barrier synchronization

    Science.gov (United States)

    Nicol, David M.

    1992-01-01

    Barrier synchronization is fundamental operation in parallel computation. In many contexts, at the point a processor enters a barrier it knows that it has already processed all the work required of it prior to synchronization. The alternative case, when a processor cannot enter a barrier with the assurance that it has already performed all the necessary pre-synchronization computation, is treated. The problem arises when the number of pre-sychronization messages to be received by a processor is unkown, for example, in a parallel discrete simulation or any other computation that is largely driven by an unpredictable exchange of messages. We describe an optimistic O(log sup 2 P) barrier algorithm for such problems, study its performance on a large-scale parallel system, and consider extensions to general associative reductions as well as associative parallel prefix computations.

  10. Auditory hallucinations induced by trazodone

    Science.gov (United States)

    Shiotsuki, Ippei; Terao, Takeshi; Ishii, Nobuyoshi; Hatano, Koji

    2014-01-01

    A 26-year-old female outpatient presenting with a depressive state suffered from auditory hallucinations at night. Her auditory hallucinations did not respond to blonanserin or paliperidone, but partially responded to risperidone. In view of the possibility that her auditory hallucinations began after starting trazodone, trazodone was discontinued, leading to a complete resolution of her auditory hallucinations. Furthermore, even after risperidone was decreased and discontinued, her auditory hallucinations did not recur. These findings suggest that trazodone may induce auditory hallucinations in some susceptible patients. PMID:24700048

  11. Integration of auditory and visual speech information

    NARCIS (Netherlands)

    Hall, M.; Smeele, P.M.T.; Kuhl, P.K.

    1998-01-01

    The integration of auditory and visual speech is observed when modes specify different places of articulation. Influences of auditory variation on integration were examined using consonant identifi-cation, plus quality and similarity ratings. Auditory identification predicted auditory-visual

  12. The effects of auditory contrast tuning upon speech intelligibility

    OpenAIRE

    Nathaniel J Killian; Nathaniel J Killian; Paul Watkins; Paul Watkins; Lisa Davidson; Dennis L. Barbour

    2016-01-01

    We have previously identified neurons tuned to spectral contrast of wideband sounds in auditory cortex of awake marmoset monkeys. Because additive noise alters the spectral contrast of speech, contrast-tuned neurons, if present in human auditory cortex, may aid in extracting speech from noise. Given that this cortical function may be underdeveloped in individuals with sensorineural hearing loss, incorporating biologically-inspired algorithms into external signal processing devices could provi...

  13. The Effects of Auditory Contrast Tuning upon Speech Intelligibility

    OpenAIRE

    Killian, Nathan J.; Watkins, Paul V.; Davidson, Lisa S.; Barbour, Dennis L.

    2016-01-01

    We have previously identified neurons tuned to spectral contrast of wideband sounds in auditory cortex of awake marmoset monkeys. Because additive noise alters the spectral contrast of speech, contrast-tuned neurons, if present in human auditory cortex, may aid in extracting speech from noise. Given that this cortical function may be underdeveloped in individuals with sensorineural hearing loss, incorporating biologically-inspired algorithms into external signal processing devices could provi...

  14. Primate Auditory Recognition Memory Performance Varies With Sound Type

    OpenAIRE

    Chi-Wing, Ng; Bethany, Plakke; Amy, Poremba

    2009-01-01

    Neural correlates of auditory processing, including for species-specific vocalizations that convey biological and ethological significance (e.g. social status, kinship, environment),have been identified in a wide variety of areas including the temporal and frontal cortices. However, few studies elucidate how non-human primates interact with these vocalization signals when they are challenged by tasks requiring auditory discrimination, recognition, and/or memory. The present study employs a de...

  15. Effect- and Performance-Based Auditory Feedback on Interpersonal Coordination

    Directory of Open Access Journals (Sweden)

    Tong-Hun Hwang

    2018-03-01

    Full Text Available When two individuals interact in a collaborative task, such as carrying a sofa or a table, usually spatiotemporal coordination of individual motor behavior will emerge. In many cases, interpersonal coordination can arise independently of verbal communication, based on the observation of the partners' movements and/or the object's movements. In this study, we investigate how social coupling between two individuals can emerge in a collaborative task under different modes of perceptual information. A visual reference condition was compared with three different conditions with new types of additional auditory feedback provided in real time: effect-based auditory feedback, performance-based auditory feedback, and combined effect/performance-based auditory feedback. We have developed a new paradigm in which the actions of both participants continuously result in a seamlessly merged effect on an object simulated by a tablet computer application. Here, participants should temporally synchronize their movements with a 90° phase difference and precisely adjust the finger dynamics in order to keep the object (a ball accurately rotating on a given circular trajectory on the tablet. Results demonstrate that interpersonal coordination in a joint task can be altered by different kinds of additional auditory information in various ways.

  16. Effects of sequential streaming on auditory masking using psychoacoustics and auditory evoked potentials.

    Science.gov (United States)

    Verhey, Jesko L; Ernst, Stephan M A; Yasin, Ifat

    2012-03-01

    The present study was aimed at investigating the relationship between the mismatch negativity (MMN) and psychoacoustical effects of sequential streaming on comodulation masking release (CMR). The influence of sequential streaming on CMR was investigated using a psychoacoustical alternative forced-choice procedure and electroencephalography (EEG) for the same group of subjects. The psychoacoustical data showed, that adding precursors comprising of only off-signal-frequency maskers abolished the CMR. Complementary EEG data showed an MMN irrespective of the masker envelope correlation across frequency when only the off-signal-frequency masker components were present. The addition of such precursors promotes a separation of the on- and off-frequency masker components into distinct auditory objects preventing the auditory system from using comodulation as an additional cue. A frequency-specific adaptation changing the representation of the flanking bands in the streaming conditions may also contribute to the reduction of CMR in the stream conditions, however, it is unlikely that adaptation is the primary reason for the streaming effect. A neurophysiological correlate of sequential streaming was found in EEG data using MMN, but the magnitude of the MMN was not correlated with the audibility of the signal in CMR experiments. Dipole source analysis indicated different cortical regions involved in processing auditory streaming and modulation detection. In particular, neural sources for processing auditory streaming include cortical regions involved in decision-making. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Interactive rhythmic auditory stimulation reinstates natural 1/f timing in gait of Parkinson's patients.

    Directory of Open Access Journals (Sweden)

    Michael J Hove

    Full Text Available Parkinson's disease (PD and basal ganglia dysfunction impair movement timing, which leads to gait instability and falls. Parkinsonian gait consists of random, disconnected stride times--rather than the 1/f structure observed in healthy gait--and this randomness of stride times (low fractal scaling predicts falling. Walking with fixed-tempo Rhythmic Auditory Stimulation (RAS can improve many aspects of gait timing; however, it lowers fractal scaling (away from healthy 1/f structure and requires attention. Here we show that interactive rhythmic auditory stimulation reestablishes healthy gait dynamics in PD patients. In the experiment, PD patients and healthy participants walked with a no auditory stimulation, b fixed-tempo RAS, and c interactive rhythmic auditory stimulation. The interactive system used foot sensors and nonlinear oscillators to track and mutually entrain with the human's step timing. Patients consistently synchronized with the interactive system, their fractal scaling returned to levels of healthy participants, and their gait felt more stable to them. Patients and healthy participants rarely synchronized with fixed-tempo RAS, and when they did synchronize their fractal scaling declined from healthy 1/f levels. Five minutes after removing the interactive rhythmic stimulation, the PD patients' gait retained high fractal scaling, suggesting that the interaction stabilized the internal rhythm generating system and reintegrated timing networks. The experiment demonstrates that complex interaction is important in the (reemergence of 1/f structure in human behavior and that interactive rhythmic auditory stimulation is a promising therapeutic tool for improving gait of PD patients.

  18. Synchronous imaging of coherent plasma fluctuations.

    Science.gov (United States)

    Haskey, S R; Thapar, N; Blackwell, B D; Howard, J

    2014-03-01

    A new method for imaging high frequency plasma fluctuations is described. A phase locked loop and field programmable gate array are used to generate gating triggers for an intensified CCD camera. A reference signal from another diagnostic such as a magnetic probe ensures that the triggers are synchronous with the fluctuation being imaged. The synchronous imaging technique allows effective frame rates exceeding millions per second, good signal to noise through the accumulation of multiple exposures per frame, and produces high resolution images without generating excessive quantities of data. The technique can be used to image modes in the MHz range opening up the possibility of spectrally filtered high resolution imaging of MHD instabilities that produce sufficient light fluctuations. Some examples of projection images of plasma fluctuations on the H-1NF heliac obtained using this approach are presented here.

  19. Synchronization of networks

    Indian Academy of Sciences (India)

    time. Both the number of nodes and the edges connecting the nodes can vary with time. Such a time-varying topology can occur in social networks, computer networks, WWW, biological systems, spread of epidemics etc. Here, we investigate the synchronization properties of networks with time-varying structure and compare.

  20. Synchronization of networks

    Indian Academy of Sciences (India)

    We study the synchronization of coupled dynamical systems on networks. The dynamics is governed by a local nonlinear oscillator for each node of the network and interactions connecting different nodes via the links of the network. We consider existence and stability conditions for both single- and multi-cluster ...

  1. (statcom) in synchronous compensator

    African Journals Online (AJOL)

    eobe

    for adoption of advanced control technologies such as Flexible Alternating Current Transmission System (FACTS) with fast ... APPLICATION OF STATIC SYNCHRONOUS COMPENSATOR (STATCOM) IN IMPROVING POWER SYSTEM PERFORMANCE, R.A Jokojeje .... supply at bus i and is the reactive power demand at.

  2. Damping torque analysis of VSC-based system utilizing power synchronization control

    Science.gov (United States)

    Fu, Q.; Du, W. J.; Zheng, K. Y.; Wang, H. F.

    2017-05-01

    Power synchronization control is a new control strategy of VSC-HVDC for connecting a weak power system. Different from the vector control method, this control method utilizes the internal synchronization mechanism in ac systems, in principle, similar to the operation of a synchronous machine. So that the parameters of controllers in power synchronization control will change the electromechanical oscillation modes and make an impact on the transient stability of power system. This paper present a mathematical model for small-signal stability analysis of VSC station used power synchronization control and analyse the impact of the dynamic interactions by calculating the contribution of the damping torque from the power synchronization control, besides, the parameters of controllers which correspond to damping torque and synchronous torque in the power synchronization control is defined respectively. At the end of the paper, an example power system is presented to demonstrate and validate the theoretical analysis and associated conclusions are made.

  3. Persistent fluctuations in stride intervals under fractal auditory stimulation.

    Science.gov (United States)

    Marmelat, Vivien; Torre, Kjerstin; Beek, Peter J; Daffertshofer, Andreas

    2014-01-01

    Stride sequences of healthy gait are characterized by persistent long-range correlations, which become anti-persistent in the presence of an isochronous metronome. The latter phenomenon is of particular interest because auditory cueing is generally considered to reduce stride variability and may hence be beneficial for stabilizing gait. Complex systems tend to match their correlation structure when synchronizing. In gait training, can one capitalize on this tendency by using a fractal metronome rather than an isochronous one? We examined whether auditory cues with fractal variations in inter-beat intervals yield similar fractal inter-stride interval variability as isochronous auditory cueing in two complementary experiments. In Experiment 1, participants walked on a treadmill while being paced by either an isochronous or a fractal metronome with different variation strengths between beats in order to test whether participants managed to synchronize with a fractal metronome and to determine the necessary amount of variability for participants to switch from anti-persistent to persistent inter-stride intervals. Participants did synchronize with the metronome despite its fractal randomness. The corresponding coefficient of variation of inter-beat intervals was fixed in Experiment 2, in which participants walked on a treadmill while being paced by non-isochronous metronomes with different scaling exponents. As expected, inter-stride intervals showed persistent correlations similar to self-paced walking only when cueing contained persistent correlations. Our results open up a new window to optimize rhythmic auditory cueing for gait stabilization by integrating fractal fluctuations in the inter-beat intervals.

  4. Auditory psychophysics: spectrotemporal representation of signals

    NARCIS (Netherlands)

    de Boer, E.; Dreschler, W. A.

    1987-01-01

    The study of audition has widened: Having been concentrated in the 1960s on a few topics like pitch perception, binaural hearing, and fatigue, it now spans many more subjects. In the present paper we have emphasized the following topics: frequency analysis--this topic includes spectral integration

  5. Bioacoustic Signal Classification in Cat Auditory Cortex

    Science.gov (United States)

    1994-01-01

    in rhesus monkeys that were close to the human boundaries between voiced and voiceless consonants. Baru (19󈨏) discussed the parameters involved in...grant N00014-91-J-1317, the Coleman Fund, and Hearing Research Inc. nI 24 REFERENCES Baru , A.V. Discrimination of synthesized vowels /a/ and /i/ with

  6. Auditory Processing Disorder (For Parents)

    Science.gov (United States)

    ... Noisy, loosely structured classrooms could be very frustrating. Auditory memory problems: This is when a child has difficulty remembering information such as directions, lists, or study materials. It can ... later"). Auditory discrimination problems: This is when a child has ...

  7. Auditory functions in children at schools for the deaf.

    Science.gov (United States)

    Karatas, Erkan; Kanlikama, Muzaffer; Mumbuc, Semih

    2006-01-01

    OBJECTIVE: To evaluate auditory functions in children at schools for the deaf in Turkey. DESIGN: A total of 218 children who were attending the school for deaf children were involved in the study. Familial and medical histories were obtained, and otoscopic examinations were performed. Immittance audiometry, acoustic reflex testing, pure tone audiometry, otoacoustic emission and auditory brain stem response tests were performed. RESULTS: The mean age of identification of hearing loss was 48 months. Impacted wax was the most common otoscopic finding that was seen in 49 (22.47%) of children. Nontype-A tympanograms were found in 18 (8.25%) of children. One-hundred-eighty-nine (86.69%) children had profound hearing loss, and 29 (10.3%) had severe hearing loss on pure tone audiometry. On auditory brain stem response testing, 192 (88.07%) children had profound hearing loss, and 26 (11.41%) had severe hearing loss. Only one child had auditory neuropathy/dys-synchrony, as his otoacoustic emission results were normal without synchronous auditory brain stem responses. The hearing threshold levels were found >105 dB in 28 children only with pure tone audiometry. CONCLUSION: Early auditory screening is necessary to identify the children at risk. All hearing disorders cannot be detected by subjective or objective audiometric tests only. Pure tone audiometry still has a role in determining hearing threshold levels. The audiological research directions should be directed towards routine pure tone audiometry, otoacoustic emission and auditory brain stem response assessment for all hearing impaired children to enable an successful treatment. Images Figure 1 Figure 2 Figure 4 PMID:16708506

  8. A denotational theory of synchronous reactive systems

    OpenAIRE

    Benveniste , Albert; Le Guernic , Paul; Sorel , Yves; Sorine , Michel

    1992-01-01

    International audience; In this paper, systems which interact permanently with their environments are considered. Such systems are encountered, for instance, in real-time control or signal processing systems, C3-systems, and man-machine interfaces, to mention just a few cases. The design and implementation of such systems require a concurrent programming language which can be used to verify and synthesize the synchronization mechanisms, and to perform transformations of the concurrent source ...

  9. Modularity in Sensory Auditory Memory

    OpenAIRE

    Clement, Sylvain; Moroni, Christine; Samson, Séverine

    2004-01-01

    The goal of this paper was to review various experimental and neuropsychological studies that support the modular conception of auditory sensory memory or auditory short-term memory. Based on initial findings demonstrating that verbal sensory memory system can be dissociated from a general auditory memory store at the functional and anatomical levels. we reported a series of studies that provided evidence in favor of multiple auditory sensory stores specialized in retaining eit...

  10. Mode-locking neurodynamics predict human auditory brainstem responses to musical intervals.

    Science.gov (United States)

    Lerud, Karl D; Almonte, Felix V; Kim, Ji Chul; Large, Edward W

    2014-02-01

    The auditory nervous system is highly nonlinear. Some nonlinear responses arise through active processes in the cochlea, while others may arise in neural populations of the cochlear nucleus, inferior colliculus and higher auditory areas. In humans, auditory brainstem recordings reveal nonlinear population responses to combinations of pure tones, and to musical intervals composed of complex tones. Yet the biophysical origin of central auditory nonlinearities, their signal processing properties, and their relationship to auditory perception remain largely unknown. Both stimulus components and nonlinear resonances are well represented in auditory brainstem nuclei due to neural phase-locking. Recently mode-locking, a generalization of phase-locking that implies an intrinsically nonlinear processing of sound, has been observed in mammalian auditory brainstem nuclei. Here we show that a canonical model of mode-locked neural oscillation predicts the complex nonlinear population responses to musical intervals that have been observed in the human brainstem. The model makes predictions about auditory signal processing and perception that are different from traditional delay-based models, and may provide insight into the nature of auditory population responses. We anticipate that the application of dynamical systems analysis will provide the starting point for generic models of auditory population dynamics, and lead to a deeper understanding of nonlinear auditory signal processing possibly arising in excitatory-inhibitory networks of the central auditory nervous system. This approach has the potential to link neural dynamics with the perception of pitch, music, and speech, and lead to dynamical models of auditory system development. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. A secure communication scheme using projective chaos synchronization

    International Nuclear Information System (INIS)

    Li Zhigang; Xu Daolin

    2004-01-01

    Most secure communication schemes using chaotic dynamics are based on identical synchronization. In this paper, we show the possibility of secure communication using projective synchronization (PS). The unpredictability of the scaling factor in projective synchronization can additionally enhance the security of communication. It is also showed that the scaling factor can be employed to improve the robustness against noise contamination. The feasibility of the communication scheme in high-dimensional chaotic systems, such as the hyperchaotic Roessler system, is demonstrated. Numerical results show the success in transmitting a sound signal through chaotic systems

  12. Multivariate sensitivity to voice during auditory categorization.

    Science.gov (United States)

    Lee, Yune Sang; Peelle, Jonathan E; Kraemer, David; Lloyd, Samuel; Granger, Richard

    2015-09-01

    Past neuroimaging studies have documented discrete regions of human temporal cortex that are more strongly activated by conspecific voice sounds than by nonvoice sounds. However, the mechanisms underlying this voice sensitivity remain unclear. In the present functional MRI study, we took a novel approach to examining voice sensitivity, in which we applied a signal detection paradigm to the assessment of multivariate pattern classification among several living and nonliving categories of auditory stimuli. Within this framework, voice sensitivity can be interpreted as a distinct neural representation of brain activity that correctly distinguishes human vocalizations from other auditory object categories. Across a series of auditory categorization tests, we found that bilateral superior and middle temporal cortex consistently exhibited robust sensitivity to human vocal sounds. Although the strongest categorization was in distinguishing human voice from other categories, subsets of these regions were also able to distinguish reliably between nonhuman categories, suggesting a general role in auditory object categorization. Our findings complement the current evidence of cortical sensitivity to human vocal sounds by revealing that the greatest sensitivity during categorization tasks is devoted to distinguishing voice from nonvoice categories within human temporal cortex. Copyright © 2015 the American Physiological Society.

  13. Audio-visual synchronization in reading while listening to texts: Effects on visual behavior and verbal learning

    OpenAIRE

    Gerbier , Emilie; Bailly , Gérard; Bosse , Marie-Line

    2018-01-01

    International audience; Reading while listening to texts (RWL) is a promising way to improve the learning benefits provided by a reading experience. In an exploratory study, we investigated the effect of synchronizing the highlighting of words (visual) with their auditory (speech) counterpart during a RWL task. Forty French children from 3rd to 5th grade read short stories in their native language while hearing the story spoken by a narrator. In the non-synchronized (S-) condition the text wa...

  14. The observer-based synchronization and parameter estimation of a ...

    Indian Academy of Sciences (India)

    Haipeng Su

    2017-10-31

    Oct 31, 2017 ... For exam- ple, the adaptive-impulsive synchronization and estima- tion of parameters of chaotic systems only by using discontinuous drive signals are .... c > 0,. (3) then system (2) will synchronize system (1) in the sense of limt→∞ e1 = limt→∞ e2 = limt→∞ e3 = 0, where e1 = ˆx1 − x1,e2 = ˆx2 − x2,e3 ...

  15. A synchronization system to digitalize TJ-1 Tokamak data

    International Nuclear Information System (INIS)

    Guasp, J.; Perez-Navarro, A.; Pacios, L.

    1983-01-01

    At TJ-1 Tokamak signals are stored on a 60-channel magnetic memory. In this report, a system to address those channels and synchronize readout is presented. Digitalized signals are stored in structured files on PDP-11/34 magnetic disks. (author)

  16. A Synchronous Multi-Body Sensor Platform in a Wireless Body Sensor Network: Design and Implementation

    OpenAIRE

    Gil, Yeongjoon; Wu, Wanqing; Lee, Jungtae

    2012-01-01

    Background: Human life can be further improved if diseases and disorders can be predicted before they become dangerous, by correctly recognizing signals from the human body, so in order to make disease detection more precise, various body-signals need to be measured simultaneously in a synchronized manner. Object: This research aims at developing an integrated system for measuring four signals (EEG, ECG, respiration, and PPG) and simultaneously producing synchronous signals on a Wireless Body...

  17. Methods for constructing time synchronous networks. Part 1. Consideration and experiment of time synchronizing functions and devices; Zenkei jikoku dokimo no kosei shuho. 1. Jikoku doki hoshiki no kino kento to jikkenteki kensho

    Energy Technology Data Exchange (ETDEWEB)

    Serizawa, Y.; Kitamura, K.; Myojin, M.; Shimizu, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Nenohi, H.; Morimitsu, M.; Masui, O.; Matsushima, T. [NEC Corp., Tokyo (Japan)

    1996-03-01

    For the purpose of the back-up protection of regional power line system and the protection and control of accident influence, construction methods of time synchronizing network have been investigated. This paper proposes a method suitable for business power communication. For the synchronization between stations, transmission delay and its fluctuation have to be measured accurately by transmitting time signals between stations. Based on the observed delay values, the function of time correction (phase synchronizing control) of synchronized station is required. A mutual type synchronizing method was proposed, to which a sampling synchronization method of carrier relay system for transmission line protection was applied. In this method, transmission of time signals and measurement of delays are mutually conducted between stations, and phases of independent transmitters of the both stations are controlled so as to be equivalent. This method is characterized by the suppression of delays with fluctuation in the same direction of two-way transmission. For the transmission of time signals, two types of synchronizing devices were employed, i.e., synchronous and asynchronous manners. In the former, frequency synchronous network of SDH (synchronous digital hierarchy) was synchronized. In the latter, a carrier relay device was utilized independent of frequency synchronous network. It was expected that a synchronous network with an order of {mu}s can be constructed. 11 refs., 21 figs., 3 tabs.

  18. Test-retest consistency of speech-evoked auditory brainstem responses in typically-developing children

    OpenAIRE

    Hornickel, Jane; Knowles, Erica; Kraus, Nina

    2011-01-01

    The click-evoked auditory brainstem response (ABR) is widely used in clinical settings, partly due to its predictability and high test-retest consistency. More recently, the speech-evoked ABR has been used to evaluate subcortical processing of complex signals, allowing for the objective assessment of biological processes underlying auditory function and auditory processing deficits not revealed by responses to clicks. Test-retest reliability of some components of speech-evoked ABRs has been s...

  19. Modeling auditory processing and speech perception in hearing-impaired listeners

    OpenAIRE

    Jepsen, Morten Løve; Pedersen, Michael Syskind; Dau, Torsten

    2010-01-01

    A better understanding of how the human auditory system represents and analyzes sounds and how hearing impairment affects such processing is of great interest for researchers in the fields of auditory neuroscience, audiology, and speech communication as well as for applications in hearing-instrument and speech technology. In this thesis, the primary focus was on the development and evaluation of a computational model of human auditory signal-processing and perception. The model was initially ...

  20. Amplitude-modulated stimuli reveal auditory-visual interactions in brain activity and brain connectivity

    Directory of Open Access Journals (Sweden)

    Mark eLaing

    2015-10-01

    Full Text Available The temporal congruence between auditory and visual signals coming from the same source can be a powerful means by which the brain integrates information from different senses. To investigate how the brain uses temporal information to integrate auditory and visual information from continuous yet unfamiliar stimuli, we use amplitude-modulated tones and size-modulated shapes with which we could manipulate the temporal congruence between the sensory signals. These signals were independently modulated at a slow or a fast rate. Participants were presented with auditory-only, visual-only or auditory-visual (AV trials in the scanner. On AV trials, the auditory and visual signal could have the same (AV congruent or different modulation rates (AV incongruent. Using psychophysiological interaction analyses, we found that auditory regions showed increased functional connectivity predominantly with frontal regions for AV incongruent relative to AV congruent stimuli. We further found that superior temporal regions, shown previously to integrate auditory and visual signals, showed increased connectivity with frontal and parietal regions for the same contrast. Our findings provide evidence that both activity in a network of brain regions and their connectivity are important for auditory-visual integration, and help to bridge the gap between transient and familiar AV stimuli used in previous studies.

  1. Effect of conductive hearing loss on central auditory function

    Directory of Open Access Journals (Sweden)

    Arash Bayat

    Full Text Available Abstract Introduction: It has been demonstrated that long-term Conductive Hearing Loss (CHL may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP. It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. Objective: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. Methods: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control, aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. Results: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p = 0.004; left: p 0.05. Conclusion: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.

  2. Effect of conductive hearing loss on central auditory function.

    Science.gov (United States)

    Bayat, Arash; Farhadi, Mohammad; Emamdjomeh, Hesam; Saki, Nader; Mirmomeni, Golshan; Rahim, Fakher

    It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p=0.004; left: phearing for both sides (phearing loss in either group (p>0.05). The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  3. You can't stop the music: reduced auditory alpha power and coupling between auditory and memory regions facilitate the illusory perception of music during noise.

    Science.gov (United States)

    Müller, Nadia; Keil, Julian; Obleser, Jonas; Schulz, Hannah; Grunwald, Thomas; Bernays, René-Ludwig; Huppertz, Hans-Jürgen; Weisz, Nathan

    2013-10-01

    Our brain has the capacity of providing an experience of hearing even in the absence of auditory stimulation. This can be seen as illusory conscious perception. While increasing evidence postulates that conscious perception requires specific brain states that systematically relate to specific patterns of oscillatory activity, the relationship between auditory illusions and oscillatory activity remains mostly unexplained. To investigate this we recorded brain activity with magnetoencephalography and collected intracranial data from epilepsy patients while participants listened to familiar as well as unknown music that was partly replaced by sections of pink noise. We hypothesized that participants have a stronger experience of hearing music throughout noise when the noise sections are embedded in familiar compared to unfamiliar music. This was supported by the behavioral results showing that participants rated the perception of music during noise as stronger when noise was presented in a familiar context. Time-frequency data show that the illusory perception of music is associated with a decrease in auditory alpha power pointing to increased auditory cortex excitability. Furthermore, the right auditory cortex is concurrently synchronized with the medial temporal lobe, putatively mediating memory aspects associated with the music illusion. We thus assume that neuronal activity in the highly excitable auditory cortex is shaped through extensive communication between the auditory cortex and the medial temporal lobe, thereby generating the illusion of hearing music during noise. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Synchronizing XPath Views

    DEFF Research Database (Denmark)

    Pedersen, Dennis; Pedersen, Torben Bach

    2004-01-01

    . However, the XML data sources are often independent of the data consumers and may change their schemas without notification, invalidating the XML views defined by the data consumers. This requires the view definitions to be updated to reflect the new structure of the data sources, a process termed view......The increasing availability of XML-based data sources, e.g., for publishing data on the WWW, means that more and more applications (data consumers) rely on accessing and using XML data. Typically, the access is achieved by defining views over the XML data, and accessing data through these views...... synchronization. XPath is the most commonly used language for retrieving parts of XML documents, and is thus an important cornerstone for XML view definitions. This paper presents techniques for discovering schema changes in XML data sources and synchronizing XPath-based views to reflect these schema changes...

  5. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  6. Familiarity with music increases walking speed in rhythmic auditory cuing.

    Science.gov (United States)

    Leow, Li-Ann; Rinchon, Cricia; Grahn, Jessica

    2015-03-01

    Rhythmic auditory stimulation (RAS) is a gait rehabilitation method in which patients synchronize footsteps to a metronome or musical beats. Although RAS with music can ameliorate gait abnormalities, outcomes vary, possibly because music properties, such as groove or familiarity, differ across interventions. To optimize future interventions, we assessed how initially familiar and unfamiliar low-groove and high-groove music affected synchronization accuracy and gait in healthy individuals. We also experimentally increased music familiarity using repeated exposure to initially unfamiliar songs. Overall, familiar music elicited faster stride velocity and less variable strides, as well as better synchronization performance (matching of step tempo to beat tempo). High-groove music, as reported previously, led to faster stride velocity than low-groove music. We propose two mechanisms for familiarity's effects. First, familiarity with the beat structure reduces cognitive demands of synchronizing, leading to better synchronization performance and faster, less variable gait. Second, familiarity might have elicited faster gait by increasing enjoyment of the music, as enjoyment was higher after repeated exposure to initially low-enjoyment songs. Future studies are necessary to dissociate the contribution of these mechanisms to the observed RAS effects of familiar music on gait. © 2015 New York Academy of Sciences.

  7. Auditory Memory for Timbre

    Science.gov (United States)

    McKeown, Denis; Wellsted, David

    2009-01-01

    Psychophysical studies are reported examining how the context of recent auditory stimulation may modulate the processing of new sounds. The question posed is how recent tone stimulation may affect ongoing performance in a discrimination task. In the task, two complex sounds occurred in successive intervals. A single target component of one complex…

  8. Programmable synchronous communications module

    International Nuclear Information System (INIS)

    Horelick, D.

    1979-10-01

    The functional characteristics of a programmable, synchronous serial communications CAMAC module with buffering in block format are described. Both bit and byte oriented protocols can be handled in full duplex depending on the program implemented. The main elements of the module are a Signetics 2652 Multi-Protocol Communications Controller, a Zilog Z-808 8 bit microprocessor with PROM and RAM, and FIFOs for buffering

  9. Synchronization of stochastic systems: from paddlefish electroreceptors to human epileptic glial cell cultures

    Science.gov (United States)

    Neiman, Alexander

    2000-03-01

    Synchronization is one of the fundamental nonlinear phenomena observed in nature. We have studied stochastic synchronization in the electrosensitive system of the paddlefish, Polyodon spathula and have also applied synchronization analysis to networks of glial cells cultured from brain tissue of patients with severe epilepsy. We also present theoretical and numerical models for stochastic synchronization. The electrosensitive system of the paddlefish consists of tens of thousands of electroreceptors located mainly on the "rostrum", which serves as an antenna to locate plankton. Each electroreceptor is a noisy oscillator with natural frequencies in the range of 30-90 Hz. We study synchronization in vivo due to 3-20 Hz external periodic electric fields, which correspond to natural signals produced by Daphnia, the usual prey of paddlefish. We find that for signals whose strengths are in the range that paddlefish customarily encounter in the wild, synchronization coding offers a plausible alternative to the more usual rate coding. We also have studied mutual synchronization between different electroreceptors. Although the spontaneous firing of distant electroreceptors is not synchronized, synchronization is observed when external periodic or even noisy electric fields are applied. We have applied the same analysis techniques to examine synchronization between groups of glial cells. In contrast to cultures of healthy astrocytes, which demonstrate calcium waves, the networks from epileptic tissue are characterized by spatially disordered hyper activity. Nevertheless, we have found that, in many cases, synchronized activity is a rather typical for tissue taken from the uncus region of the brain.

  10. Synchronous monitoring of muscle dynamics and electromyogram

    Science.gov (United States)

    Zakir Hossain, M.; Grill, Wolfgang

    2011-04-01

    A non-intrusive novel detection scheme has been implemented to detect the lateral muscle extension, force of the skeletal muscle and the motor action potential (EMG) synchronously. This allows the comparison of muscle dynamics and EMG signals as a basis for modeling and further studies to determine which architectural parameters are most sensitive to changes in muscle activity. For this purpose the transmission time for ultrasonic chirp signal in the frequency range of 100 kHz to 2.5 MHz passing through the muscle under observation and respective motor action potentials are recorded synchronously to monitor and quantify biomechanical parameters related to muscle performance. Additionally an ultrasonic force sensor has been employed for monitoring. Ultrasonic traducers are placed on the skin to monitor muscle expansion. Surface electrodes are placed suitably to pick up the potential for activation of the monitored muscle. Isometric contraction of the monitored muscle is ensured by restricting the joint motion with the ultrasonic force sensor. Synchronous monitoring was initiated by a software activated audio beep starting at zero time of the subsequent data acquisition interval. Computer controlled electronics are used to generate and detect the ultrasonic signals and monitor the EMG signals. Custom developed software and data analysis is employed to analyze and quantify the monitored data. Reaction time, nerve conduction speed, latent period between the on-set of EMG signals and muscle response, degree of muscle activation and muscle fatigue development, rate of energy expenditure and motor neuron recruitment rate in isometric contraction, and other relevant parameters relating to muscle performance have been quantified with high spatial and temporal resolution.

  11. Experience drives synchronization

    DEFF Research Database (Denmark)

    Pallesen, Karen Johanne; Bailey, Christopher J; Brattico, Elvira

    2015-01-01

    Musical expertise is associated with structural and functional changes in the brain that underlie facilitated auditory perception. We investigated whether the phase locking (PL) and amplitude modulations (AM) of neuronal oscillations in response to musical chords are correlated with musical......, while watching a silenced movie. We then analyzed the PL and AM of ongoing oscillations in the theta (4–8 Hz) alpha (8–14 Hz), beta- (14–30 Hz) and gamma- (30–80 Hz) bands to these chords. We found that musical expertise was associated with strengthened PL of ongoing oscillations to chords over a wide...

  12. Psychophysical and Neural Correlates of Auditory Attraction and Aversion

    Science.gov (United States)

    Patten, Kristopher Jakob

    This study explores the psychophysical and neural processes associated with the perception of sounds as either pleasant or aversive. The underlying psychophysical theory is based on auditory scene analysis, the process through which listeners parse auditory signals into individual acoustic sources. The first experiment tests and confirms that a self-rated pleasantness continuum reliably exists for 20 various stimuli (r = .48). In addition, the pleasantness continuum correlated with the physical acoustic characteristics of consonance/dissonance (r = .78), which can facilitate auditory parsing processes. The second experiment uses an fMRI block design to test blood oxygen level dependent (BOLD) changes elicited by a subset of 5 exemplar stimuli chosen from Experiment 1 that are evenly distributed over the pleasantness continuum. Specifically, it tests and confirms that the pleasantness continuum produces systematic changes in brain activity for unpleasant acoustic stimuli beyond what occurs with pleasant auditory stimuli. Results revealed that the combination of two positively and two negatively valenced experimental sounds compared to one neutral baseline control elicited BOLD increases in the primary auditory cortex, specifically the bilateral superior temporal gyrus, and left dorsomedial prefrontal cortex; the latter being consistent with a frontal decision-making process common in identification tasks. The negatively-valenced stimuli yielded additional BOLD increases in the left insula, which typically indicates processing of visceral emotions. The positively-valenced stimuli did not yield any significant BOLD activation, consistent with consonant, harmonic stimuli being the prototypical acoustic pattern of auditory objects that is optimal for auditory scene analysis. Both the psychophysical findings of Experiment 1 and the neural processing findings of Experiment 2 support that consonance is an important dimension of sound that is processed in a manner that aids

  13. Visual Information Present in Infragranular Layers of Mouse Auditory Cortex.

    Science.gov (United States)

    Morrill, Ryan J; Hasenstaub, Andrea R

    2018-03-14

    The cerebral cortex is a major hub for the convergence and integration of signals from across the sensory modalities; sensory cortices, including primary regions, are no exception. Here we show that visual stimuli influence neural firing in the auditory cortex of awake male and female mice, using multisite probes to sample single units across multiple cortical layers. We demonstrate that visual stimuli influence firing in both primary and secondary auditory cortex. We then determine the laminar location of recording sites through electrode track tracing with fluorescent dye and optogenetic identification using layer-specific markers. Spiking responses to visual stimulation occur deep in auditory cortex and are particularly prominent in layer 6. Visual modulation of firing rate occurs more frequently at areas with secondary-like auditory responses than those with primary-like responses. Auditory cortical responses to drifting visual gratings are not orientation-tuned, unlike visual cortex responses. The deepest cortical layers thus appear to be an important locus for cross-modal integration in auditory cortex. SIGNIFICANCE STATEMENT The deepest layers of the auditory cortex are often considered its most enigmatic, possessing a wide range of cell morphologies and atypical sensory responses. Here we show that, in mouse auditory cortex, these layers represent a locus of cross-modal convergence, containing many units responsive to visual stimuli. Our results suggest that this visual signal conveys the presence and timing of a stimulus rather than specifics about that stimulus, such as its orientation. These results shed light on both how and what types of cross-modal information is integrated at the earliest stages of sensory cortical processing. Copyright © 2018 the authors 0270-6474/18/382854-09$15.00/0.

  14. Signal detection

    International Nuclear Information System (INIS)

    Tholomier, M.

    1985-01-01

    In a scanning electron microscope, whatever is the measured signal, the same set is found: incident beam, sample, signal detection, signal amplification. The resulting signal is used to control the spot luminosity with the observer cathodoscope. This is synchronized with the beam scanning on the sample; on the cathodoscope, the image in secondary electrons, backscattered electrons,... of the sample surface is reconstituted. The best compromise must be found between a register time low enough to remove eventual variations (under the incident beam) of the nature of the observed phenomenon, and a good spatial resolution of the image and a signal-to-noise ratio high enough. The noise is one of the basic limitations of the scanning electron microscope performance. The whose measurement line must be optimized to reduce it [fr

  15. Auditory and Visual Differences in Time Perception? An Investigation from a Developmental Perspective with Neuropsychological Tests

    Science.gov (United States)

    Zelanti, Pierre S.; Droit-Volet, Sylvie

    2012-01-01

    Adults and children (5- and 8-year-olds) performed a temporal bisection task with either auditory or visual signals and either a short (0.5-1.0s) or long (4.0-8.0s) duration range. Their working memory and attentional capacities were assessed by a series of neuropsychological tests administered in both the auditory and visual modalities. Results…

  16. Anatomy and Physiology of the Auditory Tracts

    Directory of Open Access Journals (Sweden)

    Mohammad hosein Hekmat Ara

    1999-03-01

    Full Text Available Hearing is one of the excel sense of human being. Sound waves travel through the medium of air and enter the ear canal and then hit the tympanic membrane. Middle ear transfer almost 60-80% of this mechanical energy to the inner ear by means of “impedance matching”. Then, the sound energy changes to traveling wave and is transferred based on its specific frequency and stimulates organ of corti. Receptors in this organ and their synapses transform mechanical waves to the neural waves and transfer them to the brain. The central nervous system tract of conducting the auditory signals in the auditory cortex will be explained here briefly.

  17. Animal models for auditory streaming

    Science.gov (United States)

    Itatani, Naoya

    2017-01-01

    Sounds in the natural environment need to be assigned to acoustic sources to evaluate complex auditory scenes. Separating sources will affect the analysis of auditory features of sounds. As the benefits of assigning sounds to specific sources accrue to all species communicating acoustically, the ability for auditory scene analysis is widespread among different animals. Animal studies allow for a deeper insight into the neuronal mechanisms underlying auditory scene analysis. Here, we will review the paradigms applied in the study of auditory scene analysis and streaming of sequential sounds in animal models. We will compare the psychophysical results from the animal studies to the evidence obtained in human psychophysics of auditory streaming, i.e. in a task commonly used for measuring the capability for auditory scene analysis. Furthermore, the neuronal correlates of auditory streaming will be reviewed in different animal models and the observations of the neurons’ response measures will be related to perception. The across-species comparison will reveal whether similar demands in the analysis of acoustic scenes have resulted in similar perceptual and neuronal processing mechanisms in the wide range of species being capable of auditory scene analysis. This article is part of the themed issue ‘Auditory and visual scene analysis’. PMID:28044022

  18. Forced synchronization of autonomous dynamical Boolean networks

    International Nuclear Information System (INIS)

    Rivera-Durón, R. R.; Campos-Cantón, E.; Campos-Cantón, I.; Gauthier, Daniel J.

    2015-01-01

    We present the design of an autonomous time-delay Boolean network realized with readily available electronic components. Through simulations and experiments that account for the detailed nonlinear response of each circuit element, we demonstrate that a network with five Boolean nodes displays complex behavior. Furthermore, we show that the dynamics of two identical networks display near-instantaneous synchronization to a periodic state when forced by a common periodic Boolean signal. A theoretical analysis of the network reveals the conditions under which complex behavior is expected in an individual network and the occurrence of synchronization in the forced networks. This research will enable future experiments on autonomous time-delay networks using readily available electronic components with dynamics on a slow enough time-scale so that inexpensive data collection systems can faithfully record the dynamics

  19. Forced synchronization of autonomous dynamical Boolean networks

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Durón, R. R., E-mail: roberto.rivera@ipicyt.edu.mx; Campos-Cantón, E., E-mail: eric.campos@ipicyt.edu.mx [División de Matemáticas Aplicadas, Instituto Potosino de Investigación Científica y Tecnológica A. C., Camino a la Presa San José 2055, Col. Lomas 4 Sección, C.P. 78216, San Luis Potosí, S.L.P. (Mexico); Campos-Cantón, I. [Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, C.P. 78000, San Luis Potosí, S.L.P. (Mexico); Gauthier, Daniel J. [Department of Physics and Center for Nonlinear and Complex Systems, Duke University, Box 90305, Durham, North Carolina 27708 (United States)

    2015-08-15

    We present the design of an autonomous time-delay Boolean network realized with readily available electronic components. Through simulations and experiments that account for the detailed nonlinear response of each circuit element, we demonstrate that a network with five Boolean nodes displays complex behavior. Furthermore, we show that the dynamics of two identical networks display near-instantaneous synchronization to a periodic state when forced by a common periodic Boolean signal. A theoretical analysis of the network reveals the conditions under which complex behavior is expected in an individual network and the occurrence of synchronization in the forced networks. This research will enable future experiments on autonomous time-delay networks using readily available electronic components with dynamics on a slow enough time-scale so that inexpensive data collection systems can faithfully record the dynamics.

  20. The transient ladder synchronization of chaotic systems

    International Nuclear Information System (INIS)

    Chen, H.-K.; Sheu, L.-J.

    2006-01-01

    A new type for chaotically synchronizing systems, transient ladder chaos synchronization, is proposed in this Letter. For some physical systems, chaotic synchronization is possible in only some of the variables. It is shown that, for the non-synchronizing variable, synchronization up to a constant difference for t 1 = 2 is possible. The transient ladder chaos synchronization and anti-synchronization are illustrated by using two identical chaotic Froude pendulums. Numerical simulations are shown for demonstration

  1. Wiener and Volterra analyses applied to the auditory system.

    Science.gov (United States)

    Eggermont, J J

    1993-04-01

    The application of a particular branch of non-linear system analysis, the functional series expansion or integral method, to the auditory system is reviewed. Both the Volterra and Wiener approach are discussed and an extension of the Wiener method from its traditional white-noise stimulus approach to that of Poisson distributed clicks is presented. This type of analysis has been applied to compound and single-unit responses from the auditory nerve, cochlear nucleus, auditory midbrain and medial geniculate body. Most studies have estimated only first-order Wiener kernels but in recent years second-order Wiener and Volterra kernels have been estimated, particularly with reference to dynamic non-linearities. A particular form of second-order analysis, the Spectro Temporal Receptive Field, offers an alternative to first-order cross-correlation when phase-lock is absent. The correlation method has revealed that neural synchronization is less affected by intensity changes and damage to the hair cells than is neural firing rate. Although the presence of the static cochlear non-linearity could be demonstrated on the basis of the intensity dependence of the first-order Wiener kernel, the identification of the exact form of the nonlinearity of the peripheral auditory system on basis of higher-order Wiener kernels has so far been inconclusive. However, successes of the method can be found in the description of the dynamic non-linearities and non-linear neural interactions.

  2. Increased entorhinal-prefrontal theta synchronization parallels decreased entorhinal-hippocampal theta synchronization during learning and consolidation of associative memory.

    Directory of Open Access Journals (Sweden)

    Kaori eTakehara-Nishiuchi

    2012-01-01

    Full Text Available Memories are thought to be encoded as a distributed representation in the neocortex. The medial prefrontal cortex (mPFC has been shown to support the expression of memories that initially depend on the hippocampus (HPC, yet the mechanisms by which the HPC and mPFC access the distributed representations in the neocortex are unknown. By measuring phase synchronization of local field potential (LFP oscillations, we found that learning initiated changes in neuronal communication of the HPC and mPFC with the lateral entorhinal cortex (LEC, an area that is connected with many other neocortical regions. LFPs were recorded simultaneously from the three brain regions while rats formed an association between an auditory stimulus (CS and eyelid stimulation (US in a trace eyeblink conditioning paradigm, as well as during retention one month following learning. Over the course of learning, theta oscillations in the LEC and mPFC became strongly synchronized following the presentation of the CS on trials in which rats exhibited a conditioned response (CR, and this strengthened synchronization was also observed during retention one month after learning. In contrast, CS-evoked theta synchronization between the LEC and HPC decreased with learning. Our results suggest that the communication between the LEC and mPFC is strengthened with learning whereas the communication between the LEC and HPC is concomitantly weakened, suggesting that enhanced LEC-mPFC communication may be a key process for theoretically-proposed neocortical reorganization accompanying encoding and consolidation of a memory.

  3. Control of synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Synchronous motors are indubitably the most effective device to drive industrial production systems and robots with precision and rapidity. Their control law is thus critical for combining at the same time high productivity to reduced energy consummation. As far as possible, the control algorithms must exploit the properties of these actuators. Therefore, this work draws on well adapted models resulting from the Park's transformation, for both the most traditional machines with sinusoidal field distribution and for machines with non-sinusoidal field distribution which are more and more used in

  4. Psychic energy and synchronicity.

    Science.gov (United States)

    Zabriskie, Beverley

    2014-04-01

    Given Jung's interest in physics' formulations of psychic energy and the concept of time, overlaps and convergences in the themes addressed in analytical psychology and in quantum physics are to be expected. These are informed by the active intersections between the matter of mind and mindfulness re matter. In 1911, Jung initiated dinners with Einstein. Jung's definition of libido in the pivotal 1912 Fordham Lectures reveals the influence of these conversations. Twenty years later, a significant period in physics, Wolfgang Pauli contacted Jung. Their collaboration led to the theory of synchronicity. © 2014, The Society of Analytical Psychology.

  5. Resizing Auditory Communities

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2012-01-01

    Heard through the ears of the Canadian composer and music teacher R. Murray Schafer the ideal auditory community had the shape of a village. Schafer’s work with the World Soundscape Project in the 70s represent an attempt to interpret contemporary environments through musical and auditory...... musicalized through electro acoustic equipment installed in shops, shopping streets, transit areas etc. Urban noise no longer acts only as disturbance, but also structure and shape the places and spaces in which urban life enfold. Based on research done in Japanese shopping streets and in Copenhagen the paper...... presents some terminologies for mapping urban environments through its sonic configuration. Such probing into the practices of acoustic territorialisation may direct attention to some of the conflicting and disharmonious interests defining public inclusive domains. The paper investigates the concept...

  6. Resizing Auditory Communities

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2012-01-01

    Heard through the ears of the Canadian composer and music teacher R. Murray Schafer the ideal auditory community had the shape of a village. Schafer’s work with the World Soundscape Project in the 70s represent an attempt to interpret contemporary environments through musical and auditory...... parameters highlighting harmonious and balanced qualities while criticizing the noisy and cacophonous qualities of modern urban settings. This paper present a reaffirmation of Schafer’s central methodological claim: that environments can be analyzed through their sound, but offers considerations on the role...... musicalized through electro acoustic equipment installed in shops, shopping streets, transit areas etc. Urban noise no longer acts only as disturbance, but also structure and shape the places and spaces in which urban life enfold. Based on research done in Japanese shopping streets and in Copenhagen the paper...

  7. The role of auditory cortices in the retrieval of single-trial auditory-visual object memories.

    Science.gov (United States)

    Matusz, Pawel J; Thelen, Antonia; Amrein, Sarah; Geiser, Eveline; Anken, Jacques; Murray, Micah M

    2015-03-01

    Single-trial encounters with multisensory stimuli affect both memory performance and early-latency brain responses to visual stimuli. Whether and how auditory cortices support memory processes based on single-trial multisensory learning is unknown and may differ qualitatively and quantitatively from comparable processes within visual cortices due to purported differences in memory capacities across the senses. We recorded event-related potentials (ERPs) as healthy adults (n = 18) performed a continuous recognition task in the auditory modality, discriminating initial (new) from repeated (old) sounds of environmental objects. Initial presentations were either unisensory or multisensory; the latter entailed synchronous presentation of a semantically congruent or a meaningless image. Repeated presentations were exclusively auditory, thus differing only according to the context in which the sound was initially encountered. Discrimination abilities (indexed by d') were increased for repeated sounds that were initially encountered with a semantically congruent image versus sounds initially encountered with either a meaningless or no image. Analyses of ERPs within an electrical neuroimaging framework revealed that early stages of auditory processing of repeated sounds were affected by prior single-trial multisensory contexts. These effects followed from significantly reduced activity within a distributed network, including the right superior temporal cortex, suggesting an inverse relationship between brain activity and behavioural outcome on this task. The present findings demonstrate how auditory cortices contribute to long-term effects of multisensory experiences on auditory object discrimination. We propose a new framework for the efficacy of multisensory processes to impact both current multisensory stimulus processing and unisensory discrimination abilities later in time. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  8. Logarithmically slow onset of synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Benkoe, Gil; Jensen, Henrik Jeldtoft [Institute for Mathematical Sciences, Imperial College London, 53 Prince' s Gate, South Kensington Campus, SW7 2PG, London (United Kingdom)], E-mail: g.benkoe@imperial.ac.uk, E-mail: h.jensen@imperial.ac.uk

    2010-04-23

    The transient of a synchronizing system is investigated, considering synchronization as a relaxation phenomenon. The stepwise establishment of synchronization is studied in the system of dynamically coupled maps introduced by Ito and Kaneko (2001 Phys. Rev. Lett. 88 028701, 2003 Phys. Rev. E 67 046226), where the plasticity of dynamical couplings might be relevant in the context of neuroscience. Logarithmically slow dynamics in the transient of a fully deterministic dynamical system are shown to occur.

  9. From sensation to percept: the neural signature of auditory event-related potentials.

    Science.gov (United States)

    Joos, Kathleen; Gilles, Annick; Van de Heyning, Paul; De Ridder, Dirk; Vanneste, Sven

    2014-05-01

    An external auditory stimulus induces an auditory sensation which may lead to a conscious auditory perception. Although the sensory aspect is well known, it is still a question how an auditory stimulus results in an individual's conscious percept. To unravel the uncertainties concerning the neural correlates of a conscious auditory percept, event-related potentials may serve as a useful tool. In the current review we mainly wanted to shed light on the perceptual aspects of auditory processing and therefore we mainly focused on the auditory late-latency responses. Moreover, there is increasing evidence that perception is an active process in which the brain searches for the information it expects to be present, suggesting that auditory perception requires the presence of both bottom-up, i.e. sensory and top-down, i.e. prediction-driven processing. Therefore, the auditory evoked potentials will be interpreted in the context of the Bayesian brain model, in which the brain predicts which information it expects and when this will happen. The internal representation of the auditory environment will be verified by sensation samples of the environment (P50, N100). When this incoming information violates the expectation, it will induce the emission of a prediction error signal (Mismatch Negativity), activating higher-order neural networks and inducing the update of prior internal representations of the environment (P300). Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Comparative analysis about dynamic performances of grid synchronization schemes

    DEFF Research Database (Denmark)

    Yi, Hao; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    For a grid-connected Voltage-Source Converter (VSC), dynamics of the grid synchronization plays an important role in affecting the converter performances and stability. Due to its significance, this paper gives a comparative analysis about some basic grid synchronization schemes, through viewpoint...... of dynamic performances, which appeared as the impacts of voltage perturbation on the estimated angle error (Δθ). The analyzed synchronization schemes cover Synchronous-Reference-Frame Phase-Locked Loop (SRF-PLL), Second-Order Generalized Integrator Frequency-Locked Loop (SOGI-FLL)-based scheme......, and Decoupled Double SRF-PLL (DDSRF-PLL), in which their small-signal models, regarding the voltage perturbation, are derived in the stationary-reference frame and compared with the frequency responses diagrams. Based on the analysis, their common features and differences are summarized and finally validated...

  11. Grid Synchronization for Distributed Generations

    DEFF Research Database (Denmark)

    Peyghami, Saeed; Mokhtari, Hossein; Blaabjerg, Frede

    2017-01-01

    Distributed generators (DGs) like photovoltaic arrays, wind turbines, and fuel cell modules, as well as distributed storage (DS) units introduce some advantages to the power systems and make it more reliable, flexible, and controllable in comparison with the conventional power systems. Grid...... of interfaces needs to be synchronized with the grid or microgird, and hence, a precise synchronization algorithm—mostly based on phase-locked loop—is required to estimate the phase angle and frequency of the voltage at the coupling point. Unlike synchronous generators, in power electronic interfaced DGs...... grid. Therefore, the synchronization is an important issue in DGs to have a stable and reliable operation....

  12. Cohesion and Joint Speech: Right Hemisphere Contributions to Synchronized Vocal Production.

    Science.gov (United States)

    Jasmin, Kyle M; McGettigan, Carolyn; Agnew, Zarinah K; Lavan, Nadine; Josephs, Oliver; Cummins, Fred; Scott, Sophie K

    2016-04-27

    Synchronized behavior (chanting, singing, praying, dancing) is found in all human cultures and is central to religious, military, and political activities, which require people to act collaboratively and cohesively; however, we know little about the neural underpinnings of many kinds of synchronous behavior (e.g., vocal behavior) or its role in establishing and maintaining group cohesion. In the present study, we measured neural activity using fMRI while participants spoke simultaneously with another person. We manipulated whether the couple spoke the same sentence (allowing synchrony) or different sentences (preventing synchrony), and also whether the voice the participant heard was "live" (allowing rich reciprocal interaction) or prerecorded (with no such mutual influence). Synchronous speech was associated with increased activity in posterior and anterior auditory fields. When, and only when, participants spoke with a partner who was both synchronous and "live," we observed a lack of the suppression of auditory cortex, which is commonly seen as a neural correlate of speech production. Instead, auditory cortex responded as though it were processing another talker's speech. Our results suggest that detecting synchrony leads to a change in the perceptual consequences of one's own actions: they are processed as though they were other-, rather than self-produced. This may contribute to our understanding of synchronized behavior as a group-bonding tool. Synchronized human behavior, such as chanting, dancing, and singing, are cultural universals with functional significance: these activities increase group cohesion and cause participants to like each other and behave more prosocially toward each other. Here we use fMRI brain imaging to investigate the neural basis of one common form of cohesive synchronized behavior: joint speaking (e.g., the synchronous speech seen in chants, prayers, pledges). Results showed that joint speech recruits additional right hemisphere

  13. Cohesion and Joint Speech: Right Hemisphere Contributions to Synchronized Vocal Production

    Science.gov (United States)

    Jasmin, Kyle M.; McGettigan, Carolyn; Agnew, Zarinah K.; Lavan, Nadine; Josephs, Oliver; Cummins, Fred

    2016-01-01

    Synchronized behavior (chanting, singing, praying, dancing) is found in all human cultures and is central to religious, military, and political activities, which require people to act collaboratively and cohesively; however, we know little about the neural underpinnings of many kinds of synchronous behavior (e.g., vocal behavior) or its role in establishing and maintaining group cohesion. In the present study, we measured neural activity using fMRI while participants spoke simultaneously with another person. We manipulated whether the couple spoke the same sentence (allowing synchrony) or different sentences (preventing synchrony), and also whether the voice the participant heard was “live” (allowing rich reciprocal interaction) or prerecorded (with no such mutual influence). Synchronous speech was associated with increased activity in posterior and anterior auditory fields. When, and only when, participants spoke with a partner who was both synchronous and “live,” we observed a lack of the suppression of auditory cortex, which is commonly seen as a neural correlate of speech production. Instead, auditory cortex responded as though it were processing another talker's speech. Our results suggest that detecting synchrony leads to a change in the perceptual consequences of one's own actions: they are processed as though they were other-, rather than self-produced. This may contribute to our understanding of synchronized behavior as a group-bonding tool. SIGNIFICANCE STATEMENT Synchronized human behavior, such as chanting, dancing, and singing, are cultural universals with functional significance: these activities increase group cohesion and cause participants to like each other and behave more prosocially toward each other. Here we use fMRI brain imaging to investigate the neural basis of one common form of cohesive synchronized behavior: joint speaking (e.g., the synchronous speech seen in chants, prayers, pledges). Results showed that joint speech recruits

  14. An auditory feature detection circuit for sound pattern recognition.

    Science.gov (United States)

    Schöneich, Stefan; Kostarakos, Konstantinos; Hedwig, Berthold

    2015-09-01

    From human language to birdsong and the chirps of insects, acoustic communication is based on amplitude and frequency modulation of sound signals. Whereas frequency processing starts at the level of the hearing organs, temporal features of the sound amplitude such as rhythms or pulse rates require processing by central auditory neurons. Besides several theoretical concepts, brain circuits that detect temporal features of a sound signal are poorly understood. We focused on acoustically communicating field crickets and show how five neurons in the brain of females form an auditory feature detector circuit for the pulse pattern of the male calling song. The processing is based on a coincidence detector mechanism that selectively responds when a direct neural response and an intrinsically delayed response to the sound pulses coincide. This circuit provides the basis for auditory mate recognition in field crickets and reveals a principal mechanism of sensory processing underlying the perception of temporal patterns.

  15. Early, but not late visual distractors affect movement synchronization to a temporal-spatial visual cue.

    Science.gov (United States)

    Booth, Ashley J; Elliott, Mark T

    2015-01-01

    The ease of synchronizing movements to a rhythmic cue is dependent on the modality of the cue presentation: timing accuracy is much higher when synchronizing with discrete auditory rhythms than an equivalent visual stimulus presented through flashes. However, timing accuracy is improved if the visual cue presents spatial as well as temporal information (e.g., a dot following an oscillatory trajectory). Similarly, when synchronizing with an auditory target metronome in the presence of a second visual distracting metronome, the distraction is stronger when the visual cue contains spatial-temporal information rather than temporal only. The present study investigates individuals' ability to synchronize movements to a temporal-spatial visual cue in the presence of same-modality temporal-spatial distractors. Moreover, we investigated how increasing the number of distractor stimuli impacted on maintaining synchrony with the target cue. Participants made oscillatory vertical arm movements in time with a vertically oscillating white target dot centered on a large projection screen. The target dot was surrounded by 2, 8, or 14 distractor dots, which had an identical trajectory to the target but at a phase lead or lag of 0, 100, or 200 ms. We found participants' timing performance was only affected in the phase-lead conditions and when there were large numbers of distractors present (8 and 14). This asymmetry suggests participants still rely on salient events in the stimulus trajectory to synchronize movements. Subsequently, distractions occurring in the window of attention surrounding those events have the maximum impact on timing performance.

  16. Amplitude-modulated stimuli reveal auditory-visual interactions in brain activity and brain connectivity.

    Science.gov (United States)

    Laing, Mark; Rees, Adrian; Vuong, Quoc C

    2015-01-01

    The temporal congruence between auditory and visual signals coming from the same source can be a powerful means by which the brain integrates information from different senses. To investigate how the brain uses temporal information to integrate auditory and visual information from continuous yet unfamiliar stimuli, we used amplitude-modulated tones and size-modulated shapes with which we could manipulate the temporal congruence between the sensory signals. These signals were independently modulated at a slow or a fast rate. Participants were presented with auditory-only, visual-only, or auditory-visual (AV) trials in the fMRI scanner. On AV trials, the auditory and visual signal could have the same (AV congruent) or different modulation rates (AV incongruent). Using psychophysiological interaction analyses, we found that auditory regions showed increased functional connectivity predominantly with frontal regions for AV incongruent relative to AV congruent stimuli. We further found that superior temporal regions, shown previously to integrate auditory and visual signals, showed increased connectivity with frontal and parietal regions for the same contrast. Our findings provide evidence that both activity in a network of brain regions and their connectivity are important for AV integration, and help to bridge the gap between transient and familiar AV stimuli used in previous studies.

  17. Development of the auditory system

    OpenAIRE

    Litovsky, Ruth

    2015-01-01

    Auditory development involves changes in the peripheral and central nervous system along the auditory pathways, and these occur naturally, and in response to stimulation. Human development occurs along a trajectory that can last decades, and is studied using behavioral psychophysics, as well as physiologic measurements with neural imaging. The auditory system constructs a perceptual space that takes information from objects and groups, segregates sounds, and provides meaning and access to com...

  18. FPGA based fast synchronous serial multi-wire links synchronization

    Science.gov (United States)

    Pozniak, Krzysztof T.

    2013-10-01

    The paper debates synchronization method of multi-wire, serial link of constant latency, by means of pseudo-random numbers generators. The solution was designed for various families of FPGA circuits. There were debated synchronization algorithm and functional structure of parameterized transmitter and receiver modules. The modules were realized in VHDL language in a behavioral form.

  19. Neural Encoding of Auditory Features during Music Perception and Imagery.

    Science.gov (United States)

    Martin, Stephanie; Mikutta, Christian; Leonard, Matthew K; Hungate, Dylan; Koelsch, Stefan; Shamma, Shihab; Chang, Edward F; Millán, José Del R; Knight, Robert T; Pasley, Brian N

    2017-10-27

    Despite many behavioral and neuroimaging investigations, it remains unclear how the human cortex represents spectrotemporal sound features during auditory imagery, and how this representation compares to auditory perception. To assess this, we recorded electrocorticographic signals from an epileptic patient with proficient music ability in 2 conditions. First, the participant played 2 piano pieces on an electronic piano with the sound volume of the digital keyboard on. Second, the participant replayed the same piano pieces, but without auditory feedback, and the participant was asked to imagine hearing the music in his mind. In both conditions, the sound output of the keyboard was recorded, thus allowing precise time-locking between the neural activity and the spectrotemporal content of the music imagery. This novel task design provided a unique opportunity to apply receptive field modeling techniques to quantitatively study neural encoding during auditory mental imagery. In both conditions, we built encoding models to predict high gamma neural activity (70-150 Hz) from the spectrogram representation of the recorded sound. We found robust spectrotemporal receptive fields during auditory imagery with substantial, but not complete overlap in frequency tuning and cortical location compared to receptive fields measured during auditory perception. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Auditory Neuropathy: Findings of Behavioral, Physiological and Neurophysiological Tests

    Directory of Open Access Journals (Sweden)

    Mohammad Farhadi

    2006-12-01

    Full Text Available Background and Aim: Auditory neuropathy (AN can be diagnosed by abnormal auditory brainstem response (ABR, in the presence of normal cochlear microphonic (CM and otoacoustic emissions (OAEs.The aim of this study was to investigate the ABR and other electrodiagnostic test results of 6 patients suspicious to AN with problems in speech recognition. Materials and Methods: this cross sectional study was conducted on 6 AN patients with different ages evaluated by pure tone audiometry, speech discrimination score (SDS , immittance audiometry. ElectroCochleoGraphy , ABR, middle latency response (MLR, Late latency response (LLR, and OAEs. Results: Behavioral pure tone audiometric tests showed moderate to profound hearing loss. SDS was so poor which is not in accordance with pure tone thresholds. All patients had normal tympanogram but absent acoustic reflexes. CMs and OAEs were within normal limits. There was no contra lateral suppression of OAEs. None of cases had normal ABR or MLR although LLR was recorded in 4. Conclusion: All patients in this study are typical cases of auditory neuropathy. Despite having abnormal input, LLR remains normal that indicates differences in auditory evoked potentials related to required neural synchrony. These findings show that auditory cortex may play a role in regulating presentation of deficient signals along auditory pathways in primary steps.

  1. Primate auditory recognition memory performance varies with sound type.

    Science.gov (United States)

    Ng, Chi-Wing; Plakke, Bethany; Poremba, Amy

    2009-10-01

    Neural correlates of auditory processing, including for species-specific vocalizations that convey biological and ethological significance (e.g., social status, kinship, environment), have been identified in a wide variety of areas including the temporal and frontal cortices. However, few studies elucidate how non-human primates interact with these vocalization signals when they are challenged by tasks requiring auditory discrimination, recognition and/or memory. The present study employs a delayed matching-to-sample task with auditory stimuli to examine auditory memory performance of rhesus macaques (Macaca mulatta), wherein two sounds are determined to be the same or different. Rhesus macaques seem to have relatively poor short-term memory with auditory stimuli, and we examine if particular sound types are more favorable for memory performance. Experiment 1 suggests memory performance with vocalization sound types (particularly monkey), are significantly better than when using non-vocalization sound types, and male monkeys outperform female monkeys overall. Experiment 2, controlling for number of sound exemplars and presentation pairings across types, replicates Experiment 1, demonstrating better performance or decreased response latencies, depending on trial type, to species-specific monkey vocalizations. The findings cannot be explained by acoustic differences between monkey vocalizations and the other sound types, suggesting the biological, and/or ethological meaning of these sounds are more effective for auditory memory. 2009 Elsevier B.V.

  2. Direct Contribution of Auditory Motion Information to Sound-Induced Visual Motion Perception

    Directory of Open Access Journals (Sweden)

    Souta Hidaka

    2011-10-01

    Full Text Available We have recently demonstrated that alternating left-right sound sources induce motion perception to static visual stimuli along the horizontal plane (SIVM: sound-induced visual motion perception, Hidaka et al., 2009. The aim of the current study was to elucidate whether auditory motion signals, rather than auditory positional signals, can directly contribute to the SIVM. We presented static visual flashes at retinal locations outside the fovea together with a lateral auditory motion provided by a virtual stereo noise source smoothly shifting in the horizontal plane. The flashes appeared to move in the situation where auditory positional information would have little influence on the perceived position of visual stimuli; the spatiotemporal position of the flashes was in the middle of the auditory motion trajectory. Furthermore, the auditory motion altered visual motion perception in a global motion display; in this display, different localized motion signals of multiple visual stimuli were combined to produce a coherent visual motion perception so that there was no clear one-to-one correspondence between the auditory stimuli and each visual stimulus. These findings suggest the existence of direct interactions between the auditory and visual modalities in motion processing and motion perception.

  3. Auditory Perceptual Abilities Are Associated with Specific Auditory Experience

    Directory of Open Access Journals (Sweden)

    Yael Zaltz

    2017-11-01

    Full Text Available The extent to which auditory experience can shape general auditory perceptual abilities is still under constant debate. Some studies show that specific auditory expertise may have a general effect on auditory perceptual abilities, while others show a more limited influence, exhibited only in a relatively narrow range associated with the area of expertise. The current study addresses this issue by examining experience-dependent enhancement in perceptual abilities in the auditory domain. Three experiments were performed. In the first experiment, 12 pop and rock musicians and 15 non-musicians were tested in frequency discrimination (DLF, intensity discrimination, spectrum discrimination (DLS, and time discrimination (DLT. Results showed significant superiority of the musician group only for the DLF and DLT tasks, illuminating enhanced perceptual skills in the key features of pop music, in which miniscule changes in amplitude and spectrum are not critical to performance. The next two experiments attempted to differentiate between generalization and specificity in the influence of auditory experience, by comparing subgroups of specialists. First, seven guitar players and eight percussionists were tested in the DLF and DLT tasks that were found superior for musicians. Results showed superior abilities on the DLF task for guitar players, though no difference between the groups in DLT, demonstrating some dependency of auditory learning on the specific area of expertise. Subsequently, a third experiment was conducted, testing a possible influence of vowel density in native language on auditory perceptual abilities. Ten native speakers of German (a language characterized by a dense vowel system of 14 vowels, and 10 native speakers of Hebrew (characterized by a sparse vowel system of five vowels, were tested in a formant discrimination task. This is the linguistic equivalent of a DLS task. Results showed that German speakers had superior formant

  4. Fast Burst Synchronization for Power Line Communication Systems

    Directory of Open Access Journals (Sweden)

    Lampe Lutz

    2007-01-01

    Full Text Available Fast burst synchronization is an important requirement in asynchronous communication networks, where devices transmit short data packets in an unscheduled fashion. Such a synchronization is typically achieved by means of a preamble sent in front of the data packet. In this paper, we study fast burst synchronization for power line communication (PLC systems operating below 500 kHz and transmitting data rates of up to about 500 kbps as it is typical in various PLC network applications. In particular, we are concerned with the receiver processing of the preamble signal and the actual design of preambles suitable for fast burst synchronization in such PLC systems. Our approach is comprehensive in that it takes into account the most distinctive characteristics of the power line channel, which are multipath propagation, highly varying path loss, and disturbance by impulse noise, as well as important practical constraints, especially the need for spectral shaping of the preamble signal and fast adjustment of the automatic gain control (AGC. In fact, we regard the explicit incorporation of these various requirements into the preamble design as the main contribution of this work. We devise an optimization criterion and a stochastic algorithm to search for suitable preamble sequences. A comprehensive performance comparison of a designed and two conventional preambles shows that the designed sequence is superior in terms of (a fast burst synchronization in various transmission environments, (b fast AGC adjustment, and (c compliance of its spectrum with the spectral mask applied to the data transmit signal.

  5. Auditory agnosia as a clinical symptom of childhood adrenoleukodystrophy.

    Science.gov (United States)

    Furushima, Wakana; Kaga, Makiko; Nakamura, Masako; Gunji, Atsuko; Inagaki, Masumi

    2015-08-01

    To investigate detailed auditory features in patients with auditory impairment as the first clinical symptoms of childhood adrenoleukodystrophy (CSALD). Three patients who had hearing difficulty as the first clinical signs and/or symptoms of ALD. Precise examination of the clinical characteristics of hearing and auditory function was performed, including assessments of pure tone audiometry, verbal sound discrimination, otoacoustic emission (OAE), and auditory brainstem response (ABR), as well as an environmental sound discrimination test, a sound lateralization test, and a dichotic listening test (DLT). The auditory pathway was evaluated by MRI in each patient. Poor response to calling was detected in all patients. Two patients were not aware of their hearing difficulty, and had been diagnosed with normal hearing by otolaryngologists at first. Pure-tone audiometry disclosed normal hearing in all patients. All patients showed a normal wave V ABR threshold. Three patients showed obvious difficulty in discriminating verbal sounds, environmental sounds, and sound lateralization and strong left-ear suppression in a dichotic listening test. However, once they discriminated verbal sounds, they correctly understood the meaning. Two patients showed elongation of the I-V and III-V interwave intervals in ABR, but one showed no abnormality. MRIs of these three patients revealed signal changes in auditory radiation including in other subcortical areas. The hearing features of these subjects were diagnosed as auditory agnosia and not aphasia. It should be emphasized that when patients are suspected to have hearing impairment but have no abnormalities in pure tone audiometry and/or ABR, this should not be diagnosed immediately as psychogenic response or pathomimesis, but auditory agnosia must also be considered. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  6. Global synchronization of parallel processors using clock pulse width modulation

    Science.gov (United States)

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  7. Plasticity of the auditory system: theoretical considerations

    OpenAIRE

    Kappel,Vanessa; Moreno,Ana Clara de Paula; Buss,Ceres Helena

    2011-01-01

    Auditory plasticity refers to the possibility of anatomical and/or functional changes in the system where transmission of auditory information takes place. The auditory system is often required in communication; it is important to learn how the auditory system reacts to stimuli in order to improve performance in individual communication of subjects with impaired hearing. AIM: To review the literature on auditory plasticity and the possibility and ability of plastic responses in the auditory s...

  8. Auditory and non-auditory effects of noise on health

    NARCIS (Netherlands)

    Basner, M.; Babisch, W.; Davis, A.; Brink, M.; Clark, C.; Janssen, S.A.; Stansfeld, S.

    2013-01-01

    Noise is pervasive in everyday life and can cause both auditory and non-auditory health eff ects. Noise-induced hearing loss remains highly prevalent in occupational settings, and is increasingly caused by social noise exposure (eg, through personal music players). Our understanding of molecular

  9. Auditory Discrimination and Auditory Sensory Behaviours in Autism Spectrum Disorders

    Science.gov (United States)

    Jones, Catherine R. G.; Happe, Francesca; Baird, Gillian; Simonoff, Emily; Marsden, Anita J. S.; Tregay, Jenifer; Phillips, Rebecca J.; Goswami, Usha; Thomson, Jennifer M.; Charman, Tony

    2009-01-01

    It has been hypothesised that auditory processing may be enhanced in autism spectrum disorders (ASD). We tested auditory discrimination ability in 72 adolescents with ASD (39 childhood autism; 33 other ASD) and 57 IQ and age-matched controls, assessing their capacity for successful discrimination of the frequency, intensity and duration…

  10. Exploiting Schemas in Data Synchronization

    DEFF Research Database (Denmark)

    Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian

    2005-01-01

    Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety...

  11. Exploiting Schemas in Data Synchronization

    DEFF Research Database (Denmark)

    Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian

    2005-01-01

    Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety of t...

  12. Synchronizing clocks in distributed networks

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2011-01-01

    Very recently it has been shown that clocks in distributed networks cannot be synchronized precisely even in idealized situations when asymmetric delays are present [1]. In this paper by determining the clock synchronization errors in the similar settings of the impossibility result just mentioned,

  13. Synchronizing clocks in distributed networks

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2011-01-01

    While various time synchronization protocols for clocks in wired and/or wireless networks are under development, recently it has been shown by Freris, Graham and Kumar that clocks in distributed networks cannot be synchronized precisely even in idealized situations. In this paper by determining the

  14. Digital synchronization and communication techniques

    Science.gov (United States)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  15. Benefits of Synchronous Online Courses

    Science.gov (United States)

    Moser, Scott; Smith, Phil

    2015-01-01

    Most online courses are offered as "asynchronous" courses and have no real-time contact with students. The Synchronous online alternative provides normal scheduled class time and allows students to login to a virtual online classroom with the instructor. We provide an overview of two different platforms for hosting synchronous classes…

  16. Business cycle synchronization in Europe

    DEFF Research Database (Denmark)

    Bergman, Ulf Michael; Jonung, Lars

    2011-01-01

    In this paper we study business cycle synchronization in the three Scandinavian countries Denmark, Norway and Sweden prior to, during and after the Scandinavian Currency Union 1873–1913. We find that the degree of synchronization tended to increase during the currency union, thus supporting earlier...

  17. Synchronization dynamics of two different dynamical systems

    International Nuclear Information System (INIS)

    Luo, Albert C.J.; Min Fuhong

    2011-01-01

    Highlights: → Synchronization dynamics of two distinct dynamical systems. → Synchronization, de-synchronization and instantaneous synchronization. → A controlled pendulum synchronizing with the Duffing oscillator. → Synchronization invariant set. → Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.

  18. Inversion of Auditory Spectrograms, Traditional Spectrograms, and Other Envelope Representations

    DEFF Research Database (Denmark)

    Decorsière, Remi Julien Blaise; Søndergaard, Peter Lempel; MacDonald, Ewen

    2015-01-01

    Envelope representations such as the auditory or traditional spectrogram can be defined by the set of envelopes from the outputs of a filterbank. Common envelope extraction methods discard information regarding the fast fluctuations, or phase, of the signal. Thus, it is difficult to invert, or re...... to the framework is proposed, which leads to a more accurate inversion of traditional spectrograms...

  19. Stuttering Inhibition via Altered Auditory Feedback during Scripted Telephone Conversations

    Science.gov (United States)

    Hudock, Daniel; Kalinowski, Joseph

    2014-01-01

    Background: Overt stuttering is inhibited by approximately 80% when people who stutter read aloud as they hear an altered form of their speech feedback to them. However, levels of stuttering inhibition vary from 60% to 100% depending on speaking situation and signal presentation. For example, binaural presentations of delayed auditory feedback…

  20. Auditory-like filterbank: An optimal speech processor for efficient ...

    Indian Academy of Sciences (India)

    The transmitter and the receiver in a communication system have to be designed optimally with respect to one another to ensure reliable and efficient communication. Following this principle, we derive an optimal filterbank for processing speech signal in the listener's auditory system (receiver), so that maximum information ...

  1. Sequential grouping constraints on across-channel auditory processing

    DEFF Research Database (Denmark)

    Oxenham, Andrew J.; Dau, Torsten

    2005-01-01

    Søren Buus was one of the pioneers in the study of across-channel auditory processing. His influential 1985 paper showed that introducing slow fluctuations to a low-frequency masker could reduce the detection thresholds of a high-frequency signal by as much as 25 dB [S. Buus, J. Acoust. Soc. Am. 78...

  2. Accuracy of averaged auditory brainstem response amplitude and latency estimates

    DEFF Research Database (Denmark)

    Madsen, Sara Miay Kim; M. Harte, James; Elberling, Claus

    2017-01-01

    Objective: The aims were to 1) establish which of the four algorithms for estimating residual noise level and signal-to-noise ratio (SNR) in auditory brainstem responses (ABRs) perform better in terms of post-average wave-V peak latency and amplitude errors and 2) determine whether SNR or noise...

  3. Biological Impact of Music and Software-Based Auditory Training

    Science.gov (United States)

    Kraus, Nina

    2012-01-01

    Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals--both young and old--encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in…

  4. Time-sharing visual and auditory tracking tasks

    Science.gov (United States)

    Tsang, Pamela S.; Vidulich, Michael A.

    1987-01-01

    An experiment is described which examined the benefits of distributing the input demands of two tracking tasks as a function of task integrality. Visual and auditory compensatory tracking tasks were utilized. Results indicate that presenting the two tracking signals in two input modalities did not improve time-sharing efficiency. This was attributed to the difficulty insensitivity phenomenon.

  5. The synchronous active neutron detection assay system

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ''lock-in'' amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design

  6. Auditory Reserve and the Legacy of Auditory Experience

    Directory of Open Access Journals (Sweden)

    Erika Skoe

    2014-11-01

    Full Text Available Musical training during childhood has been linked to more robust encoding of sound later in life. We take this as evidence for an auditory reserve: a mechanism by which individuals capitalize on earlier life experiences to promote auditory processing. We assert that early auditory experiences guide how the reserve develops and is maintained over the lifetime. Experiences that occur after childhood, or which are limited in nature, are theorized to affect the reserve, although their influence on sensory processing may be less long-lasting and may potentially fade over time if not repeated. This auditory reserve may help to explain individual differences in how individuals cope with auditory impoverishment or loss of sensorineural function.

  7. Auditory Reserve and the Legacy of Auditory Experience

    Science.gov (United States)

    Skoe, Erika; Kraus, Nina

    2014-01-01

    Musical training during childhood has been linked to more robust encoding of sound later in life. We take this as evidence for an auditory reserve: a mechanism by which individuals capitalize on earlier life experiences to promote auditory processing. We assert that early auditory experiences guide how the reserve develops and is maintained over the lifetime. Experiences that occur after childhood, or which are limited in nature, are theorized to affect the reserve, although their influence on sensory processing may be less long-lasting and may potentially fade over time if not repeated. This auditory reserve may help to explain individual differences in how individuals cope with auditory impoverishment or loss of sensorineural function. PMID:25405381

  8. Synchronous machine parameter identification in frequency and time domain

    Directory of Open Access Journals (Sweden)

    Hasni M.

    2007-01-01

    Full Text Available This paper presents the results of a frequency and time-domain identification procedure to estimate the linear parameters of a salient-pole synchronous machine at standstill. The objective of this study is to use several input signals to identify the model structure and parameters of a salient-pole synchronous machine from standstill test data. The procedure consists to define, to conduct the standstill tests and also to identify the model structure. The signals used for identification are the different excitation voltages at standstill and the flowing current in different windings. We estimate the parameters of operational impedances, or in other words the reactance and the time constants. The tests were carried out on synchronous machine of 1.5 kVA 380V 1500 rpm.

  9. Synchronous, bilateral tonsillar carcinomas

    DEFF Research Database (Denmark)

    Saber, Camelia Nami; Grønhøj, Christian; Jensen, David Hebbelstrup

    2017-01-01

    -based, consecutive cohort of OPSCCs. METHODS: We identified all patients diagnosed with tonsillar squamous cell carcinoma (TSCC) in eastern Denmark during a 15-year period to detect the incidence of synchronous BiTSCCs. The tumours were assessed for p16Ink4a expression, the presence of HPV DNA and HPV genotypes....... Furthermore, we systematically reviewed the literature examining BiTSCCs. RESULTS: Of the total of 1119 TSCCs diagnosed in eastern Denmark from 2000 to 2014, we identified 12 BiTSCCs, nine of which initially presented as a cancer of unknown primary (CUP) in the neck. Nine cases were bilaterally HPV16 positive...... (HPV16+), while two cases were HPV16+ in one tonsil and respectively, HPV33 and HPV35 positive in the contralateral tonsil. One case was bilaterally HPV-negative. We also identified an increase in the incidence of BiTSCCs after 2012 when histological examination of the entire tonsil tissue became...

  10. How far away is plug 'n' play? Assessing the near-term potential of sonification and auditory display

    Science.gov (United States)

    Bargar, Robin

    1995-01-01

    The commercial music industry offers a broad range of plug 'n' play hardware and software scaled to music professionals and scaled to a broad consumer market. The principles of sound synthesis utilized in these products are relevant to application in virtual environments (VE). However, the closed architectures used in commercial music synthesizers are prohibitive to low-level control during real-time rendering, and the algorithms and sounds themselves are not standardized from product to product. To bring sound into VE requires a new generation of open architectures designed for human-controlled performance from interfaces embedded in immersive environments. This presentation addresses the state of the sonic arts in scientific computing and VE, analyzes research challenges facing sound computation, and offers suggestions regarding tools we might expect to become available during the next few years. A list of classes of audio functionality in VE includes sonification -- the use of sound to represent data from numerical models; 3D auditory display (spatialization and localization, also called externalization); navigation cues for positional orientation and for finding items or regions inside large spaces; voice recognition for controlling the computer; external communications between users in different spaces; and feedback to the user concerning his own actions or the state of the application interface. To effectively convey this considerable variety of signals, we apply principles of acoustic design to ensure the messages are neither confusing nor competing. We approach the design of auditory experience through a comprehensive structure for messages, and message interplay we refer to as an Automated Sound Environment. Our research addresses real-time sound synthesis, real-time signal processing and localization, interactive control of high-dimensional systems, and synchronization of sound and graphics.

  11. Dynamic links between theta executive functions and alpha storage buffers in auditory and visual working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2010-05-01

    Working memory (WM) tasks require not only distinct functions such as a storage buffer and central executive functions, but also coordination among these functions. Neuroimaging studies have revealed the contributions of different brain regions to different functional roles in WM tasks; however, little is known about the neural mechanism governing their coordination. Electroencephalographic (EEG) rhythms, especially theta and alpha, are known to appear over distributed brain regions during WM tasks, but the rhythms associated with task-relevant regional coupling have not been obtained thus far. In this study, we conducted time-frequency analyses for EEG data in WM tasks that include manipulation periods and memory storage buffer periods. We used both auditory WM tasks and visual WM tasks. The results successfully demonstrated function-specific EEG activities. The frontal theta amplitudes increased during the manipulation periods of both tasks. The alpha amplitudes increased during not only the manipulation but also the maintenance periods in the temporal area for the auditory WM and the parietal area for the visual WM. The phase synchronization analyses indicated that, under the relevant task conditions, the temporal and parietal regions show enhanced phase synchronization in the theta bands with the frontal region, whereas phase synchronization between theta and alpha is significantly enhanced only within the individual areas. Our results suggest that WM task-relevant brain regions are coordinated by distant theta synchronization for central executive functions, by local alpha synchronization for the memory storage buffer, and by theta-alpha coupling for inter-functional integration.

  12. Word Recognition in Auditory Cortex

    Science.gov (United States)

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  13. Partial Epilepsy with Auditory Features

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-07-01

    Full Text Available The clinical characteristics of 53 sporadic (S cases of idiopathic partial epilepsy with auditory features (IPEAF were analyzed and compared to previously reported familial (F cases of autosomal dominant partial epilepsy with auditory features (ADPEAF in a study at the University of Bologna, Italy.

  14. Dynamic eccentricity fault diagnosis in round rotor synchronous motors

    International Nuclear Information System (INIS)

    Ebrahimi, Bashir Mahdi; Etemadrezaei, Mohammad; Faiz, Jawad

    2011-01-01

    Research highlights: → We have presented a novel approach to detect dynamic eccentricity in round rotor synchronous motors. → We have introduced an efficient index based on processing torque using time series data mining method. → The stator current spectrum of the motor under different levels of fault and load are computed. → Winding function method has been employed to model healthy and faulty synchronous motors. -- Abstract: In this paper, a novel approach is presented to detect dynamic eccentricity in round rotor synchronous motors. For this, an efficient index is introduced based on processing developed torque using time series data mining (TSDM) method. This index can be utilized to diagnose eccentricity fault and its degree. The capability of this index to predict dynamic eccentricity is illustrated by investigation of load variation impacts on the nominated index. Stator current spectrum of the faulty synchronous motor under different loads and dynamic eccentricity degrees are computed. Effects of the dynamic eccentricity and load variation simultaneously are scrutinized on the magnitude of 17th and 19th harmonic components as traditional indices for eccentricity fault diagnosis in synchronous motors. Necessity signals and parameters for processing and feature extraction are evaluated by winding function method which is employed to model healthy and faulty synchronous motors.

  15. A new type of chaotic synchronization with application to communication systems

    International Nuclear Information System (INIS)

    Kharel, Rupak; Busawon, Krishna

    2011-01-01

    In this paper, we propose a new methodology to synchronize a class of chaotic systems starting from different initial conditions under some given conditions. The method we propose is not based on the unidirectional synchronization method like the one proposed by Pecora-Caroll. The proposed method is unique in the sense that the chaotic oscillators to be synchronized have no direct connection between them; that is, there is no signal being sent from one to the other. Simulation result is presented to show the synchronization performance.

  16. Synchronization of OFDM at low SNR over an AWGN channel

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria; Dimitrova, D.C.; Blom, K.C.H.; Meratnia, Nirvana

    2011-01-01

    This paper is based on Extended Symbol OFDM (ES-OFDM) where symbols are extended in time. This way ES-OFDM can operate at low SNR. Each doubling of the symbol length improves the SNR performance by 3 dB in case of a coherent receiver. One of the basic questions is how to synchronize to signals far

  17. Phase Synchronization in Human EEG During Audio-Visual Stimulation

    Czech Academy of Sciences Publication Activity Database

    Teplan, M.; Šušmáková, K.; Paluš, Milan; Vejmelka, Martin

    2009-01-01

    Roč. 28, - (2009), s. 80-84 ISSN 1536-8378 Grant - others:Bilateral project between Slovak AS and AS CR(CZ-SK) Modern methods for evaluation of electrophysiological signals Source of funding: V - iné verejné zdroje Keywords : synchronization * EEG * wavelet * audio- visual stimulation Subject RIV: FH - Neurology Impact factor: 0.729, year: 2009

  18. Neural Correlates of Auditory Processing, Learning and Memory Formation in Songbirds

    Science.gov (United States)

    Pinaud, R.; Terleph, T. A.; Wynne, R. D.; Tremere, L. A.

    Songbirds have emerged as powerful experimental models for the study of auditory processing of complex natural communication signals. Intact hearing is necessary for several behaviors in developing and adult animals including vocal learning, territorial defense, mate selection and individual recognition. These behaviors are thought to require the processing, discrimination and memorization of songs. Although much is known about the brain circuits that participate in sensorimotor (auditory-vocal) integration, especially the ``song-control" system, less is known about the anatomical and functional organization of central auditory pathways. Here we discuss findings associated with a telencephalic auditory area known as the caudomedial nidopallium (NCM). NCM has attracted significant interest as it exhibits functional properties that may support higher order auditory functions such as stimulus discrimination and the formation of auditory memories. NCM neurons are vigorously dr iven by auditory stimuli. Interestingly, these responses are selective to conspecific, relative to heterospecific songs and artificial stimuli. In addition, forms of experience-dependent plasticity occur in NCM and are song-specific. Finally, recent experiments employing high-throughput quantitative proteomics suggest that complex protein regulatory pathways are engaged in NCM as a result of auditory experience. These molecular cascades are likely central to experience-associated plasticity of NCM circuitry and may be part of a network of calcium-driven molecular events that support the formation of auditory memory traces.

  19. Impairments in musical abilities reflected in the auditory brainstem: evidence from congenital amusia.

    Science.gov (United States)

    Lehmann, Alexandre; Skoe, Erika; Moreau, Patricia; Peretz, Isabelle; Kraus, Nina

    2015-07-01

    Congenital amusia is a neurogenetic condition, characterized by a deficit in music perception and production, not explained by hearing loss, brain damage or lack of exposure to music. Despite inferior musical performance, amusics exhibit normal auditory cortical responses, with abnormal neural correlates suggested to lie beyond auditory cortices. Here we show, using auditory brainstem responses to complex sounds in humans, that fine-grained automatic processing of sounds is impoverished in amusia. Compared with matched non-musician controls, spectral amplitude was decreased in amusics for higher harmonic components of the auditory brainstem response. We also found a delayed response to the early transient aspects of the auditory stimulus in amusics. Neural measures of spectral amplitude and response timing correlated with participants' behavioral assessments of music processing. We demonstrate, for the first time, that amusia affects how complex acoustic signals are processed in the auditory brainstem. This neural signature of amusia mirrors what is observed in musicians, such that the aspects of the auditory brainstem responses that are enhanced in musicians are degraded in amusics. By showing that gradients of music abilities are reflected in the auditory brainstem, our findings have implications not only for current models of amusia but also for auditory functioning in general. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  20. Peripheral Auditory Mechanisms

    CERN Document Server

    Hall, J; Hubbard, A; Neely, S; Tubis, A

    1986-01-01

    How weIl can we model experimental observations of the peripheral auditory system'? What theoretical predictions can we make that might be tested'? It was with these questions in mind that we organized the 1985 Mechanics of Hearing Workshop, to bring together auditory researchers to compare models with experimental observations. Tbe workshop forum was inspired by the very successful 1983 Mechanics of Hearing Workshop in Delft [1]. Boston University was chosen as the site of our meeting because of the Boston area's role as a center for hearing research in this country. We made a special effort at this meeting to attract students from around the world, because without students this field will not progress. Financial support for the workshop was provided in part by grant BNS- 8412878 from the National Science Foundation. Modeling is a traditional strategy in science and plays an important role in the scientific method. Models are the bridge between theory and experiment. Tbey test the assumptions made in experim...

  1. Nutritional recommendations for synchronized swimming.

    Science.gov (United States)

    Robertson, Sherry; Benardot, Dan; Mountjoy, Margo

    2014-08-01

    The sport of synchronized swimming is unique, because it combines speed, power, and endurance with precise synchronized movements and high-risk acrobatic maneuvers. Athletes must train and compete while spending a great amount of time underwater, upside down, and without the luxury of easily available oxygen. This review assesses the scientific evidence with respect to the physiological demands, energy expenditure, and body composition in these athletes. The role of appropriate energy requirements and guidelines for carbohydrate, protein, fat, and micronutrients for elite synchronized swimmers are reviewed. Because of the aesthetic nature of the sport, which prioritizes leanness, the risks of energy and macronutrient deficiencies are of significant concern. Relative Energy Deficiency in Sport and disordered eating/eating disorders are also of concern for these female athletes. An approach to the healthy management of body composition in synchronized swimming is outlined. Synchronized swimmers should be encouraged to consume a well-balanced diet with sufficient energy to meet demands and to time the intake of carbohydrate, protein, and fat to optimize performance and body composition. Micronutrients of concern for this female athlete population include iron, calcium, and vitamin D. This article reviews the physiological demands of synchronized swimming and makes nutritional recommendations for recovery, training, and competition to help optimize athletic performance and to reduce risks for weight-related medical issues that are of particular concern for elite synchronized swimmers.

  2. Generalized synchronization between chimera states

    Science.gov (United States)

    Andrzejak, Ralph G.; Ruzzene, Giulia; Malvestio, Irene

    2017-05-01

    Networks of coupled oscillators in chimera states are characterized by an intriguing interplay of synchronous and asynchronous motion. While chimera states were initially discovered in mathematical model systems, there is growing experimental and conceptual evidence that they manifest themselves also in natural and man-made networks. In real-world systems, however, synchronization and desynchronization are not only important within individual networks but also across different interacting networks. It is therefore essential to investigate if chimera states can be synchronized across networks. To address this open problem, we use the classical setting of ring networks of non-locally coupled identical phase oscillators. We apply diffusive drive-response couplings between pairs of such networks that individually show chimera states when there is no coupling between them. The drive and response networks are either identical or they differ by a variable mismatch in their phase lag parameters. In both cases, already for weak couplings, the coherent domain of the response network aligns its position to the one of the driver networks. For identical networks, a sufficiently strong coupling leads to identical synchronization between the drive and response. For non-identical networks, we use the auxiliary system approach to demonstrate that generalized synchronization is established instead. In this case, the response network continues to show a chimera dynamics which however remains distinct from the one of the driver. Hence, segregated synchronized and desynchronized domains in individual networks congregate in generalized synchronization across networks.

  3. Synchronization and NRZ-to-RZ format conversion of 10 G Ethernet packet based on a time lens

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Palushani, Evarist

    2010-01-01

    10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time.......10 G Ethernet packet with maximum frame size of 1518 bytes is synchronized to a global clock using a time lens. The 10 Gb/s NRZ signal is converted into RZ signal at the same time....

  4. Evidence of functional connectivity between auditory cortical areas revealed by amplitude modulation sound processing.

    Science.gov (United States)

    Guéguin, Marie; Le Bouquin-Jeannès, Régine; Faucon, Gérard; Chauvel, Patrick; Liégeois-Chauvel, Catherine

    2007-02-01

    The human auditory cortex includes several interconnected areas. A better understanding of the mechanisms involved in auditory cortical functions requires a detailed knowledge of neuronal connectivity between functional cortical regions. In human, it is difficult to track in vivo neuronal connectivity. We investigated the interarea connection in vivo in the auditory cortex using a method of directed coherence (DCOH) applied to depth auditory evoked potentials (AEPs). This paper presents simultaneous AEPs recordings from insular gyrus (IG), primary and secondary cortices (Heschl's gyrus and planum temporale), and associative areas (Brodmann area [BA] 22) with multilead intracerebral electrodes in response to sinusoidal modulated white noises in 4 epileptic patients who underwent invasive monitoring with depth electrodes for epilepsy surgery. DCOH allowed estimation of the causality between 2 signals recorded from different cortical sites. The results showed 1) a predominant auditory stream within the primary auditory cortex from the most medial region to the most lateral one whatever the modulation frequency, 2) unidirectional functional connection from the primary to secondary auditory cortex, 3) a major auditory propagation from the posterior areas to the anterior ones, particularly at 8, 16, and 32 Hz, and 4) a particular role of Heschl's sulcus dispatching information to the different auditory areas. These findings suggest that cortical processing of auditory information is performed in serial and parallel streams. Our data showed that the auditory propagation could not be associated to a unidirectional traveling wave but to a constant interaction between these areas that could reflect the large adaptive and plastic capacities of auditory cortex. The role of the IG is discussed.

  5. Synchronization of weighted networks and complex synchronized regions

    International Nuclear Information System (INIS)

    Duan Zhisheng; Chen Guanrong; Huang Lin

    2008-01-01

    Since the Laplacian matrices of weighted networks usually have complex eigenvalues, the problem of complex synchronized regions should be investigated carefully. The present Letter addresses this important problem by converting it to a matrix stability problem with respect to a complex parameter, which gives rise to several types of complex synchronized regions, including bounded, unbounded, disconnected, and empty regions. Because of the existence of disconnected synchronized regions, the convexity characteristic of stability for matrix pencils is further discussed. Then, some efficient methods for designing local feedback controllers and inner-linking matrices to enlarge the synchronized regions are developed and analyzed. Finally, a weighted network of smooth Chua's circuits is presented as an example for illustration

  6. Phase synchronization of oscillations in cardiovascular and respiratory systems in humans

    Science.gov (United States)

    Tankanag, Arina V.; Grinevich, Andrey A.; Tikhonova, Irina V.; Chaplygina, Alina V.; Chemeris, Nikolay K.

    2017-04-01

    Phase synchronization between blood flow oscillations of left and right forearm skin sites, heart rate variability (HRV) and breath rate were studied from healthy volunteers at rest. The degree of synchronization between the phases of the analyzed signals was estimated from the value of the wavelet phase coherence. High medians of values of phase wavelet coherence function were obtained for the endothelial, neurogenic, myogenic and cardiac intervals. Significant phase synchronization were demonstrated between HRV and skin blood flow oscillations in both left and right forearms in a wide frequency range from 0.04 to 0.4 Hz. Six participants exhibited low phase synchronization ( 0.5). This distribution was not affected by the sex or sympathovagal status of volunteers. Participants with low phase synchronization between breath rate and HRV featured low phase synchronization (cardiovascular system, in particular, with HRV and breath rate over a wide frequency range.

  7. Synchronous Design and Test of Distributed Passive Radar Systems Based on Digital Broadcasting and Television

    Directory of Open Access Journals (Sweden)

    Wan Xianrong

    2017-02-01

    Full Text Available Digital broadcasting and television are important classes of illuminators of opportunity for passive radars. Distributed and multistatic structure are the development trends for passive radars. Most modern digital broadcasting and television systems work on a network, which not only provides a natural condition to distributed passive radar but also puts forward higher requirements on the design of passive radar systems. Among those requirements, precise synchronization among the receivers and transmitters as well as among multiple receiving stations, which mainly involves frequency and time synchronization, is the first to be solved. To satisfy the synchronization requirements of distributed passive radars, a synchronization scheme based on GPS is presented in this paper. Moreover, an effective scheme based on the China Mobile Multimedia Broadcasting signal is proposed to test the system synchronization performance. Finally, the reliability of the synchronization design is verified via the distributed multistatic passive radar experiments.

  8. Design of Wireless Automatic Synchronization for the Low-Frequency Coded Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Zhenghuan Xia

    2015-01-01

    Full Text Available Low-frequency coded ground penetrating radar (GPR with a pair of wire dipole antennas has some advantages for deep detection. Due to the large distance between the two antennas, the synchronization design is a major challenge of implementing the GPR system. This paper proposes a simple and stable wireless automatic synchronization method based on our developed GPR system, which does not need any synchronization chips or modules and reduces the cost of the hardware system. The transmitter omits the synchronization preamble and pseudorandom binary sequence (PRBS at an appropriate time interval, while receiver automatically estimates the synchronization time and receives the returned signal from the underground targets. All the processes are performed in a single FPGA. The performance of the proposed synchronization method is validated with experiment.

  9. Delayed feedback control of bursting synchronization in a scale-free neuronal network.

    Science.gov (United States)

    Batista, C A S; Lopes, S R; Viana, R L; Batista, A M

    2010-01-01

    Several neurological diseases (e.g. essential tremor and Parkinson's disease) are related to pathologically enhanced synchronization of bursting neurons. Suppression of these synchronized rhythms has potential implications in electrical deep-brain stimulation research. We consider a simplified model of a neuronal network where the local dynamics presents a bursting timescale, and the connection architecture displays the scale-free property (power-law distribution of connectivity). The networks exhibit collective oscillations in the form of synchronized bursting rhythms, without affecting the fast timescale dynamics. We investigate the suppression of these synchronized oscillations using a feedback control in the form of a time-delayed signal. We located domains of bursting synchronization suppression in terms of perturbation strength and time delay, and present computational evidence that synchronization suppression is easier in scale-free networks than in the more commonly studied global (mean-field) networks.

  10. A network of networks model to study phase synchronization using structural connection matrix of human brain

    Science.gov (United States)

    Ferrari, F. A. S.; Viana, R. L.; Reis, A. S.; Iarosz, K. C.; Caldas, I. L.; Batista, A. M.

    2018-04-01

    The cerebral cortex plays a key role in complex cortical functions. It can be divided into areas according to their function (motor, sensory and association areas). In this paper, the cerebral cortex is described as a network of networks (cortex network), we consider that each cortical area is composed of a network with small-world property (cortical network). The neurons are assumed to have bursting properties with the dynamics described by the Rulkov model. We study the phase synchronization of the cortex network and the cortical networks. In our simulations, we verify that synchronization in cortex network is not homogeneous. Besides, we focus on the suppression of neural phase synchronization. Synchronization can be related to undesired and pathological abnormal rhythms in the brain. For this reason, we consider the delayed feedback control to suppress the synchronization. We show that delayed feedback control is efficient to suppress synchronous behavior in our network model when an appropriate signal intensity and time delay are defined.

  11. Synchronization Technique for Random Switching Frequency Pulse-Width Modulation

    OpenAIRE

    Apinan Aurasopon; Worawat Sa-ngiavibool

    2008-01-01

    This paper proposes a synchronized random switching frequency pulse width modulation (SRSFPWM). In this technique, the clock signal is used to control the random noise frequency which is produced by the feedback voltage of a hysteresis circuit. These make the triangular carrier frequency equaling to the random noise frequency in each switching period with the symmetrical positive and negative slopes of triangular carrier. Therefore, there is no error voltage in PWM signal. The PSpice simulate...

  12. A dominance hierarchy of auditory spatial cues in barn owls.

    Directory of Open Access Journals (Sweden)

    Ilana B Witten

    2010-04-01

    Full Text Available Barn owls integrate spatial information across frequency channels to localize sounds in space.We presented barn owls with synchronous sounds that contained different bands of frequencies (3-5 kHz and 7-9 kHz from different locations in space. When the owls were confronted with the conflicting localization cues from two synchronous sounds of equal level, their orienting responses were dominated by one of the sounds: they oriented toward the location of the low frequency sound when the sources were separated in azimuth; in contrast, they oriented toward the location of the high frequency sound when the sources were separated in elevation. We identified neural correlates of this behavioral effect in the optic tectum (OT, superior colliculus in mammals, which contains a map of auditory space and is involved in generating orienting movements to sounds. We found that low frequency cues dominate the representation of sound azimuth in the OT space map, whereas high frequency cues dominate the representation of sound elevation.We argue that the dominance hierarchy of localization cues reflects several factors: 1 the relative amplitude of the sound providing the cue, 2 the resolution with which the auditory system measures the value of a cue, and 3 the spatial ambiguity in interpreting the cue. These same factors may contribute to the relative weighting of sound localization cues in other species, including humans.

  13. Evaluation of central auditory discrimination abilities in older adults.

    Directory of Open Access Journals (Sweden)

    Claudia eFreigang

    2011-05-01

    Full Text Available The present study focuses on auditory discrimination abilities in older adults aged 65-89 years. We applied the ‘Leipzig Inventory for Patient Psychoacoustic’ (LIPP, a psychoacoustic test battery specifically designed to identify deficits in central auditory processing. These tests quantify the just noticeable differences (JND for the three basic acoustic parameters (i.e. frequency, intensity, and signal duration. Three different test modes (monaural, dichotic signal/noise [s/n] and interaural were used, stimulus level was 35dB sensation level. The tests are designed as three-alternative forced-choice procedure with a maximum-likelihood procedure estimating p=0,5 correct response value. These procedures have proven to be highly efficient and provide a reliable outcome. The measurements yielded significant age-dependent deteriorations in the ability to discriminate single acoustic features pointing to progressive impairments in central auditory processing. The degree of deterioration was correlated to the different acoustic features and to the test modes. Most prominent, interaural frequency and signal duration discrimination at low test frequencies was elevated which indicates a deterioration of time- and phase-dependent processing at brain stem and cortical levels. LIPP proves to be an effective tool to identify basic pathophysiological mechanisms and the source of a specific impairment in auditory processing of the elderly.

  14. Assessing the degree of synchronization between geophysical records using the method of instantaneous phase differences

    CSIR Research Space (South Africa)

    Botai, OJ

    2009-09-01

    Full Text Available -linear motions that are associated with seasonal signals caused by loading effects, and seismic deformation processes such as earthquakes etc. This implies that the fluctuations in the station coordinates and tropospheric parameters could be synchronized because...

  15. Auditory processing models

    DEFF Research Database (Denmark)

    Dau, Torsten

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  16. Temporal coordination in joint music performance: effects of endogenous rhythms and auditory feedback.

    Science.gov (United States)

    Zamm, Anna; Pfordresher, Peter Q; Palmer, Caroline

    2015-02-01

    Many behaviors require that individuals coordinate the timing of their actions with others. The current study investigated the role of two factors in temporal coordination of joint music performance: differences in partners' spontaneous (uncued) rate and auditory feedback generated by oneself and one's partner. Pianists performed melodies independently (in a Solo condition), and with a partner (in a duet condition), either at the same time as a partner (Unison), or at a temporal offset (Round), such that pianists heard their partner produce a serially shifted copy of their own sequence. Access to self-produced auditory information during duet performance was manipulated as well: Performers heard either full auditory feedback (Full), or only feedback from their partner (Other). Larger differences in partners' spontaneous rates of Solo performances were associated with larger asynchronies (less effective synchronization) during duet performance. Auditory feedback also influenced temporal coordination of duet performance: Pianists were more coordinated (smaller tone onset asynchronies and more mutual adaptation) during duet performances when self-generated auditory feedback aligned with partner-generated feedback (Unison) than when it did not (Round). Removal of self-feedback disrupted coordination (larger tone onset asynchronies) during Round performances only. Together, findings suggest that differences in partners' spontaneous rates of Solo performances, as well as differences in self- and partner-generated auditory feedback, influence temporal coordination of joint sensorimotor behaviors.

  17. Compression of auditory space during forward self-motion.

    Directory of Open Access Journals (Sweden)

    Wataru Teramoto

    shifts in the auditory receptive field locations driven by afferent signals from vestibular system.

  18. Cross-spectrum symbol synchronization

    Science.gov (United States)

    Mccallister, R. D.; Simon, M. K.

    1981-01-01

    A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.

  19. Incoherence-Mediated Remote Synchronization

    Science.gov (United States)

    Zhang, Liyue; Motter, Adilson E.; Nishikawa, Takashi

    2017-04-01

    In previously identified forms of remote synchronization between two nodes, the intermediate portion of the network connecting the two nodes is not synchronized with them but generally exhibits some coherent dynamics. Here we report on a network phenomenon we call incoherence-mediated remote synchronization (IMRS), in which two noncontiguous parts of the network are identically synchronized while the dynamics of the intermediate part is statistically and information-theoretically incoherent. We identify mirror symmetry in the network structure as a mechanism allowing for such behavior, and show that IMRS is robust against dynamical noise as well as against parameter changes. IMRS may underlie neuronal information processing and potentially lead to network solutions for encryption key distribution and secure communication.

  20. Beat Synchronization across the Lifespan: Intersection of Development and Musical Experience.

    Directory of Open Access Journals (Sweden)

    Elaine C Thompson

    Full Text Available Rhythmic entrainment, or beat synchronization, provides an opportunity to understand how multiple systems operate together to integrate sensory-motor information. Also, synchronization is an essential component of musical performance that may be enhanced through musical training. Investigations of rhythmic entrainment have revealed a developmental trajectory across the lifespan, showing synchronization improves with age and musical experience. Here, we explore the development and maintenance of synchronization in childhood through older adulthood in a large cohort of participants (N = 145, and also ask how it may be altered by musical experience. We employed a uniform assessment of beat synchronization for all participants and compared performance developmentally and between individuals with and without musical experience. We show that the ability to consistently tap along to a beat improves with age into adulthood, yet in older adulthood tapping performance becomes more variable. Also, from childhood into young adulthood, individuals are able to tap increasingly close to the beat (i.e., asynchronies decline with age, however, this trend reverses from younger into older adulthood. There is a positive association between proportion of life spent playing music and tapping performance, which suggests a link between musical experience and auditory-motor integration. These results are broadly consistent with previous investigations into the development of beat synchronization across the lifespan, and thus complement existing studies and present new insights offered by a different, large cross-sectional sample.

  1. Optimization models for synchronization planning

    OpenAIRE

    Morey, Christopher

    1991-01-01

    Approved for public release; distribution is unlimited Planning for the synchronization of activities on the battlefield for an Army battalion task force requires detailed planning for movement of subordinate units, allocation of personnel and assets to tasks, and many other activities to ensure that maximum damage is inflicted on an enemy force. Currently, this synchronization planning is done manually by task force officers, primarily the operations officer. The process is time consumi...

  2. Synchronization of uncertain chaotic systems using a single transmission channel

    International Nuclear Information System (INIS)

    Feng Yong; Yu Xinghuo; Sun Lixia

    2008-01-01

    This paper proposes a robust sliding mode observer for synchronization of uncertain chaotic systems with multi-nonlinearities. A new control strategy is proposed for the construction of the robust sliding mode observer, which can avoid the strict conditions in the design process of Walcott-Zak observer. A new method of multi-dimensional signal transmission via single transmission channel is proposed and applied to chaos synchronization of uncertain chaotic systems with multi-nonlinearities. The simulation results are presented to validate the method

  3. Experimental synchronization of circuit oscillations induced by common telegraph noise.

    Science.gov (United States)

    Nagai, Ken; Nakao, Hiroya

    2009-03-01

    Experimental realization and quantitative investigation of common-noise-induced synchronization of limit-cycle oscillations subject to random telegraph signals are performed using an electronic oscillator circuit. Based on our previous formulation [K. Nagai, Phys. Rev. E 71, 036217 (2005)], dynamics of the circuit is described as random-phase mappings between two limit cycles. Lyapunov exponents characterizing the degree of synchronization are estimated from experimentally determined phase maps and compared with linear damping rates of phase differences measured directly. Noisy on-off intermittency of the phase difference as predicted by the theory is also confirmed experimentally.

  4. Increase in Synchronization of Autonomic Rhythms between Individuals When Listening to Music

    Science.gov (United States)

    Bernardi, Nicolò F.; Codrons, Erwan; di Leo, Rita; Vandoni, Matteo; Cavallaro, Filippo; Vita, Giuseppe; Bernardi, Luciano

    2017-01-01

    In light of theories postulating a role for music in forming emotional and social bonds, here we investigated whether endogenous rhythms synchronize between multiple individuals when listening to music. Cardiovascular and respiratory recordings were taken from multiple individuals (musically trained or music-naïve) simultaneously, at rest and during a live concert comprising music excerpts with varying degrees of complexity of the acoustic envelope. Inter-individual synchronization of cardiorespiratory rhythms showed a subtle but reliable increase during passively listening to music compared to baseline. The low-level auditory features of the music were largely responsible for creating or disrupting such synchronism, explaining ~80% of its variance, over and beyond subjective musical preferences and previous musical training. Listening to simple rhythms and melodies, which largely dominate the choice of music during rituals and mass events, brings individuals together in terms of their physiological rhythms, which could explain why music is widely used to favor social bonds. PMID:29089898

  5. Hybrid synchronization of hyperchaotic Lu system

    Indian Academy of Sciences (India)

    In this paper, we study the hybrid synchronization between two identical hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid ...

  6. Hybrid synchronization of hyperchaotic Lu system

    Indian Academy of Sciences (India)

    hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid synchronization between drive and response systems using the sum and difference of ...

  7. Multiswitching combination–combination synchronization of chaotic ...

    Indian Academy of Sciences (India)

    2017-02-09

    Feb 9, 2017 ... Abstract. In this paper, a novel synchronization scheme is investigated for a class of chaotic systems. The multiswitching synchronization scheme is extended to the combination–combination synchronization scheme such that the combination of state variables of two drive systems synchronize with different ...

  8. Multiswitching combination–combination synchronization of chaotic ...

    Indian Academy of Sciences (India)

    In this paper, a novel synchronization scheme is investigated for a class of chaotic systems. Themultiswitching synchronization scheme is extended to the combination–combination synchronization scheme such that the combination of state variables of two drive systems synchronize with different combination of state ...

  9. Auditory orientation in crickets: Pattern recognition controls reactive steering

    Science.gov (United States)

    Poulet, James F. A.; Hedwig, Berthold

    2005-10-01

    Many groups of insects are specialists in exploiting sensory cues to locate food resources or conspecifics. To achieve orientation, bees and ants analyze the polarization pattern of the sky, male moths orient along the females' odor plume, and cicadas, grasshoppers, and crickets use acoustic signals to locate singing conspecifics. In comparison with olfactory and visual orientation, where learning is involved, auditory processing underlying orientation in insects appears to be more hardwired and genetically determined. In each of these examples, however, orientation requires a recognition process identifying the crucial sensory pattern to interact with a localization process directing the animal's locomotor activity. Here, we characterize this interaction. Using a sensitive trackball system, we show that, during cricket auditory behavior, the recognition process that is tuned toward the species-specific song pattern controls the amplitude of auditory evoked steering responses. Females perform small reactive steering movements toward any sound patterns. Hearing the male's calling song increases the gain of auditory steering within 2-5 s, and the animals even steer toward nonattractive sound patterns inserted into the speciesspecific pattern. This gain control mechanism in the auditory-to-motor pathway allows crickets to pursue species-specific sound patterns temporarily corrupted by environmental factors and may reflect the organization of recognition and localization networks in insects. localization | phonotaxis

  10. Prestimulus subsequent memory effects for auditory and visual events.

    Science.gov (United States)

    Otten, Leun J; Quayle, Angela H; Puvaneswaran, Bhamini

    2010-06-01

    It has been assumed that the effective encoding of information into memory primarily depends on neural activity elicited when an event is initially encountered. Recently, it has been shown that memory formation also relies on neural activity just before an event. The precise role of such activity in memory is currently unknown. Here, we address whether prestimulus activity affects the encoding of auditory and visual events, is set up on a trial-by-trial basis, and varies as a function of the type of recognition judgment an item later receives. Electrical brain activity was recorded from the scalps of 24 healthy young adults while they made semantic judgments on randomly intermixed series of visual and auditory words. Each word was preceded by a cue signaling the modality of the upcoming word. Auditory words were preceded by auditory cues and visual words by visual cues. A recognition memory test with remember/know judgments followed after a delay of about 45 min. As observed previously, a negative-going, frontally distributed modulation just before visual word onset predicted later recollection of the word. Crucially, the same effect was found for auditory words and observed on stay as well as switch trials. These findings emphasize the flexibility and general role of prestimulus activity in memory formation, and support a functional interpretation of the activity in terms of semantic preparation. At least with an unpredictable trial sequence, the activity is set up anew on each trial.

  11. Auditory short-term memory in the primate auditory cortex.

    Science.gov (United States)

    Scott, Brian H; Mishkin, Mortimer

    2016-06-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ׳working memory' bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ׳match' stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. This article is part of a Special Issue entitled SI: Auditory working memory. Published by Elsevier B.V.

  12. Multichannel spatial auditory display for speech communications

    Science.gov (United States)

    Begault, D. R.; Erbe, T.; Wenzel, E. M. (Principal Investigator)

    1994-01-01

    A spatial auditory display for multiple speech communications was developed at NASA/Ames Research Center. Input is spatialized by the use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positions at 30 degrees azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6-7 dB when the signal was spatialized to 60 or 90 degrees azimuth positions.

  13. Multichannel Spatial Auditory Display for Speed Communications

    Science.gov (United States)

    Begault, Durand R.; Erbe, Tom

    1994-01-01

    A spatial auditory display for multiple speech communications was developed at NASA/Ames Research Center. Input is spatialized by the use of simplifiedhead-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware design implementations are overviewed for the initial prototype developed for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positions at 30 degree azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6-7 dB when the signal was spatialized to 60 or 90 degree azimuth positions.

  14. Low power adder based auditory filter architecture.

    Science.gov (United States)

    Rahiman, P F Khaleelur; Jayanthi, V S

    2014-01-01

    Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT) based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

  15. Low Power Adder Based Auditory Filter Architecture

    Directory of Open Access Journals (Sweden)

    P. F. Khaleelur Rahiman

    2014-01-01

    Full Text Available Cochlea devices are powered up with the help of batteries and they should possess long working life to avoid replacing of devices at regular interval of years. Hence the devices with low power consumptions are required. In cochlea devices there are numerous filters, each responsible for frequency variant signals, which helps in identifying speech signals of different audible range. In this paper, multiplierless lookup table (LUT based auditory filter is implemented. Power aware adder architectures are utilized to add the output samples of the LUT, available at every clock cycle. The design is developed and modeled using Verilog HDL, simulated using Mentor Graphics Model-Sim Simulator, and synthesized using Synopsys Design Compiler tool. The design was mapped to TSMC 65 nm technological node. The standard ASIC design methodology has been adapted to carry out the power analysis. The proposed FIR filter architecture has reduced the leakage power by 15% and increased its performance by 2.76%.

  16. Synchronization and anti-synchronization coexist in Chen-Lee chaotic systems

    International Nuclear Information System (INIS)

    Chen, J.-H.; Chen, H.-K.; Lin, Y.-K.

    2009-01-01

    This study demonstrates that synchronization and anti-synchronization can coexist in Chen-Lee chaotic systems by direct linear coupling. Based on Lyapunov's direct method, a linear controller was designed to assure that two different types of synchronization can simultaneously be achieved. Further, the hybrid projective synchronization of Chen-Lee chaotic systems was studied using a nonlinear control scheme. The nonlinear controller was designed according to the Lyapunov stability theory to guarantee the hybrid projective synchronization, including synchronization, anti-synchronization, and projective synchronization. Finally, numerical examples are presented in order to illustrate the proposed synchronization approach.

  17. Adaptive Time Synchronization for Homogeneous WSNs

    Directory of Open Access Journals (Sweden)

    Siddhartha Chauhan

    2012-11-01

    cluster heads (CHs are synchronized with the sink and then the cluster nodes (CNs are synchronized with their respective CHs. CNs are synchronized with the help of time synchronization node (TSN chosen by the respective CHs. Simulation results show that proposed protocol requires considerably fewer synchronization messages as compared with the reference broadcast synchronization (RBS protocol and minimum variance unbiased estimation (MUVE method. Clock skew correction mechanism applied in proposed protocol guarantees long term stability and hence decreases re‐synchronization frequency thereby conserving more energy.

  18. Prenatal-choline supplementation differentially modulates timing of auditory and visual stimuli in aged rats.

    Science.gov (United States)

    Cheng, Ruey-Kuang; Scott, Allison C; Penney, Trevor B; Williams, Christina L; Meck, Warren H

    2008-10-27

    Choline supplementation of the maternal diet has a long-term facilitative effect on the interval-timing ability and temporal memory of the offspring. Here, we examined whether prenatal-choline supplementation has modality-specific effects on duration discrimination in aged (20 mo) male rats. Adult offspring of rats that were given sufficient choline in their chow (CON: 1.1 g/kg) or supplemental choline added to their drinking water (SUP: 3.5 g/kg) during embryonic days (ED) 12-17 were trained and tested on a two-modality (auditory and visual signals) duration bisection procedure (2 s vs. 8 s). Intensity (high vs. low) of the auditory and visual timing signals was systematically manipulated across test sessions such that all combinations of signal intensity by modality were tested. Psychometric response functions indicated that prenatal-choline supplementation systematically increased sensitivity to auditory signals relative to visual signals, thereby magnifying the modality effect that sounds are judged to be longer than lights of equivalent duration. In addition, sensitivity to signal duration was greater in rats given prenatal-choline supplementation, particularly at low intensities of both the auditory and visual signals. Overall, these results suggest that prenatal-choline supplementation impacts interval timing by enhancing the differences in temporal integration between auditory and visual stimuli in aged subjects.

  19. Auditory stimulus timing influences perceived duration of co-occurring visual stimuli

    Directory of Open Access Journals (Sweden)

    Vincenzo eRomei

    2011-09-01

    Full Text Available There is increasing interest in multisensory influences upon sensory-specific judgements, such as when auditory stimuli affect visual perception. Here we studied whether the duration of an auditory event can objectively affect the perceived duration of a co-occurring visual event. On each trial, participants were presented with a pair of successive flashes and had to judge whether the first or second was longer. Two beeps were presented with the flashes. The order of short and long stimuli could be the same across audition and vision (audiovisual congruent or reversed, so that the longer flash was accompanied by the shorter beep and vice versa (audiovisual incongruent; or the two beeps could have the same duration as each other. Beeps and flashes could onset synchronously or asynchronously. In a further control experiment, the beep durations were much longer (tripled than the flashes. Results showed that visual duration-discrimination sensitivity (d' was significantly higher for congruent (and significantly lower for incongruent audiovisual synchronous combinations, relative to the visual only presentation. This effect was abolished when auditory and visual stimuli were presented asynchronously, or when sound durations tripled those of flashes. We conclude that the temporal properties of co-occurring auditory stimuli influence the perceived duration of visual stimuli and that this can reflect genuine changes in visual sensitivity rather than mere response bias.

  20. Modulation of Auditory Spatial Attention by Angry Prosody: An fMRI Auditory Dot-Probe Study.

    Science.gov (United States)

    Ceravolo, Leonardo; Frühholz, Sascha; Grandjean, Didier

    2016-01-01

    Emotional stimuli have been shown to modulate attentional orienting through signals sent by subcortical brain regions that modulate visual perception at early stages of processing. Fewer studies, however, have investigated a similar effect of emotional stimuli on attentional orienting in the auditory domain together with an investigation of brain regions underlying such attentional modulation, which is the general aim of the present study. Therefore, we used an original auditory dot-probe paradigm involving simultaneously presented neutral and angry non-speech vocal utterances lateralized to either the left or the right auditory space, immediately followed by a short and lateralized single sine wave tone presented in the same (valid trial) or in the opposite space as the preceding angry voice (invalid trial). Behavioral results showed an expected facilitation effect for target detection during valid trials while functional data showed greater activation in the middle and posterior superior temporal sulci (STS) and in the medial frontal cortex for valid vs. invalid trials. The use of reaction time facilitation [absolute value of the Z-score of valid-(invalid+neutral)] as a group covariate extended enhanced activity in the amygdalae, auditory thalamus, and visual cortex. Taken together, our results suggest the involvement of a large and distributed network of regions among which the STS, thalamus, and amygdala are crucial for the decoding of angry prosody, as well as for orienting and maintaining attention within an auditory space that was previously primed by a vocal emotional event.

  1. Unidirectional synchronization of Hodgkin-Huxley neurons

    International Nuclear Information System (INIS)

    Cornejo-Perez, Octavio; Femat, Ricardo

    2005-01-01

    Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states

  2. Unidirectional synchronization of Hodgkin-Huxley neurons

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Perez, Octavio [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: octavio@ipicyt.edu.mx; Femat, Ricardo [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: rfemat@ipicyt.edu.mx

    2005-07-01

    Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states.

  3. Maps of the Auditory Cortex.

    Science.gov (United States)

    Brewer, Alyssa A; Barton, Brian

    2016-07-08

    One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.

  4. Auditory Processing Disorder in Children

    Science.gov (United States)

    ... www.nidcd.nih.gov/directory . Use the keyword “auditory processing disorders” to search for relevant organizations. Last ... Communication Problems in Children Dysphagia Quick Statistics About Voice, ...

  5. Auditory N1 reveals planning and monitoring processes during music performance.

    Science.gov (United States)

    Mathias, Brian; Gehring, William J; Palmer, Caroline

    2017-02-01

    The current study investigated the relationship between planning processes and feedback monitoring during music performance, a complex task in which performers prepare upcoming events while monitoring their sensory outcomes. Theories of action planning in auditory-motor production tasks propose that the planning of future events co-occurs with the perception of auditory feedback. This study investigated the neural correlates of planning and feedback monitoring by manipulating the contents of auditory feedback during music performance. Pianists memorized and performed melodies at a cued tempo in a synchronization-continuation task while the EEG was recorded. During performance, auditory feedback associated with single melody tones was occasionally substituted with tones corresponding to future (next), present (current), or past (previous) melody tones. Only future-oriented altered feedback disrupted behavior: Future-oriented feedback caused pianists to slow down on the subsequent tone more than past-oriented feedback, and amplitudes of the auditory N1 potential elicited by the tone immediately following the altered feedback were larger for future-oriented than for past-oriented or noncontextual (unrelated) altered feedback; larger N1 amplitudes were associated with greater slowing following altered feedback in the future condition only. Feedback-related negativities were elicited in all altered feedback conditions. In sum, behavioral and neural evidence suggests that future-oriented feedback disrupts performance more than past-oriented feedback, consistent with planning theories that posit similarity-based interference between feedback and planning contents. Neural sensory processing of auditory feedback, reflected in the N1 ERP, may serve as a marker for temporal disruption caused by altered auditory feedback in auditory-motor production tasks. © 2016 Society for Psychophysiological Research.

  6. Public channel cryptography: chaos synchronization and Hilbert's tenth problem.

    Science.gov (United States)

    Kanter, Ido; Kopelowitz, Evi; Kinzel, Wolfgang

    2008-08-22

    The synchronization process of two mutually delayed coupled deterministic chaotic maps is demonstrated both analytically and numerically. The synchronization is preserved when the mutually transmitted signals are concealed by two commutative private filters, a convolution of the truncated time-delayed output signals or some powers of the delayed output signals. The task of a passive attacker is mapped onto Hilbert's tenth problem, solving a set of nonlinear Diophantine equations, which was proven to be in the class of NP-complete problems [problems that are both NP (verifiable in nondeterministic polynomial time) and NP-hard (any NP problem can be translated into this problem)]. This bridge between nonlinear dynamics and NP-complete problems opens a horizon for new types of secure public-channel protocols.

  7. Analytical minimization of synchronicity errors in stochastic identification

    Science.gov (United States)

    Bernal, D.

    2018-01-01

    An approach to minimize error due to synchronicity faults in stochastic system identification is presented. The scheme is based on shifting the time domain signals so the phases of the fundamental eigenvector estimated from the spectral density are zero. A threshold on the mean of the amplitude-weighted absolute value of these phases, above which signal shifting is deemed justified, is derived and found to be proportional to the first mode damping ratio. It is shown that synchronicity faults do not map precisely to phasor multiplications in subspace identification and that the accuracy of spectral density estimated eigenvectors, for inputs with arbitrary spectral density, decrease with increasing mode number. Selection of a corrective strategy based on signal alignment, instead of eigenvector adjustment using phasors, is shown to be the product of the foregoing observations. Simulations that include noise and non-classical damping suggest that the scheme can provide sufficient accuracy to be of practical value.

  8. Photoacoustic microscopy achieved by microcavity synchronous parallel acquisition technique.

    Science.gov (United States)

    Tan, Zhiliang; Liao, Yanfei; Wu, Yongbo; Tang, Zhilie; Wang, Ruikang K

    2012-02-27

    We report on a sub-cellular resolution photoacoustic microscopy (PAM) system that employs microcavity synchronous parallel acquisition technique for detecting the weak photoacoustic (PA) signal excited by a modulated continuous wave (CW) laser source. The gas microcavity transducer is developed based on the fact that the bulk modulus of the gas is far less than the solid and the change of the air-gas pressure is inversely proportional to the gas volume, making it extremely sensitive to the tiny PA pressure wave. Besides, considering PA wave expends in various directions, detecting PA signals from different position and adding them together can increase the detecting sensitivity and the signal to noise ratio(SNR), then we employs two microphone to acquire PA wave synchronously and parallelly. We show that the developed PAM system is capable of label-free imaging and differentiating of the hemoglobin distribution within single red blood cells under normal and anemia conditions.

  9. Role of synchronized oscillatory brain activity for human pain perception.

    Science.gov (United States)

    Hauck, Michael; Lorenz, Jürgen; Engel, Andreas K

    2008-01-01

    The understanding of cortical pain processing in humans has significantly improved since the development of modern neuroimaging techniques. Non-invasive electrophysiological approaches such as electro- and magnetoencephalography have proven to be helpful tools for the real-time investigation of neuronal signals and synchronous communication between cortical areas. In particular, time-frequency decomposition of signals recorded with these techniques seems to be a promising approach because different pain-related oscillatory changes can be observed within different frequency bands, which are likely to be linked to specific sensory and motor functions. In this review we discuss the latest evidence on pain-induced time-frequency signals and propose that changes in oscillatory activity reflect an essential communication mechanism in the brain that is modulated during pain processing. The importance of synchronization processes for normal and pathological pain processing, such as chronic pain states, is discussed.

  10. Phenomena of synchronized response in biosystems and the possible mechanism.

    Science.gov (United States)

    Xu, Jingjing; Yang, Fan; Han, Danhong; Xu, Shengyong

    2018-02-05

    Phenomena of synchronized response is common among organs, tissues and cells in biosystems. We have analyzed and discussed three examples of synchronization in biosystems, including the direction-changing movement of paramecia, the prey behavior of flytraps, and the simultaneous discharge of electric eels. These phenomena and discussions support an electrical communication mechanism that in biosystems, the electrical signals are mainly soliton-like electromagnetic pulses, which are generated by the transient transmembrane ionic current through the ion channels and propagate along the dielectric membrane-based softmaterial waveguide network to complete synchronized responses. This transmission model implies that a uniform electrical communication mechanism might have been naturally developed in biosystem. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Underwater Time Service and Synchronization Based on Time Reversal Technique

    Science.gov (United States)

    Lu, Hao; Wang, Hai-bin; Aissa-El-Bey, Abdeldjalil; Pyndiah, Ramesh

    2010-09-01

    Real time service and synchronization are very important to many underwater systems. But the time service and synchronization in existence cannot work well due to the multi-path propagation and random phase fluctuation of signals in the ocean channel. The time reversal mirror technique can realize energy concentration through self-matching of the ocean channel and has very good spatial and temporal focusing properties. Based on the TRM technique, we present the Time Reversal Mirror Real Time service and synchronization (TRMRT) method which can bypass the processing of multi-path on the server side and reduce multi-path contamination on the client side. So TRMRT can improve the accuracy of time service. Furthermore, as an efficient and precise method of time service, TRMRT could be widely used in underwater exploration activities and underwater navigation and positioning systems.

  12. Synchronization control for ultrafast laser parallel microdrilling system

    Science.gov (United States)

    Zhai, Zhongsheng; Kuang, Zheng; Ouyang, Jinlei; Liu, Dun; Perrie, Walter; Edwardson, Stuart P.; Dearden, Geoff

    2014-11-01

    Ultrafast lasers, emitting ultra-short pulses of light, generally of the order of femtoseconds to ten picoseconds, are widely used in micro-processing with the advantage of very little thermal damage. Parallel micro-processing is seen significant developments in laser fabrication, thanking to the spatial light modulator (SLM) which can concert single beam to multiple beams through computer generate holograms (CGHs). However, without synchronization control, on the conditions of changing different holograms or processing on large area beyond scanning galvo's ability, the fabrication will be interrupted constantly for changing holograms and moving the stages. Therefore, synchronization control is very important to improve the convenience and application of parallel micro-processing. A synchronization control method, carried out through two application software: SAMLight (or WaveRunner) and Labview, is presented in this paper. SAMLight is used to control the laser and the scanning galvo to implement microprocessing, and the developed program with Labview is used to control the SLM and motion stages. The synchronization signals, transmitted between the two software, are utilized by a National Instruments (NI) device USB-6008. Using optimal control methods, the synchronized system can easily and automatically accomplish complicated fabrications with minimum time. A multi-drilling application is provided to verify the affectivity of the synchronized control method. It uses multiple annular beams, generated by superimposing multi-beam CGH onto a diffractive axicon CGH, to drill multiple holes at one time, and it can automatically finish different patterns based on synchronization control. This drilling way is an optical trepanning and it avoids huge laser energy waste with attenuation. The multi-beam CGHs, generated by the Grating and Lens algorithm, are different for different patterns. The processing is over 200 times faster than traditional mechanical trepanning

  13. Activation of auditory white matter tracts as revealed by functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Yakunina, Natalia; Nam, Eui-Cheol [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University, Department of Otolaryngology, School of Medicine, Chuncheon, Kangwon-do (Korea, Republic of); Kim, Tae Su [Kangwon National University Hospital, Department of Otolaryngology, Chuncheon (Korea, Republic of); Kim, Sam Soo [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University, Department of Radiology, School of Medicine, Chuncheon (Korea, Republic of)

    2014-07-15

    The ability of functional magnetic resonance imaging (fMRI) to detect activation in brain white matter (WM) is controversial. In particular, studies on the functional activation of WM tracts in the central auditory system are scarce. We utilized fMRI to assess and characterize the entire auditory WM pathway under robust experimental conditions involving the acquisition of a large number of functional volumes, the application of broadband auditory stimuli of high intensity, and the use of sparse temporal sampling to avoid scanner noise effects and increase signal-to-noise ratio. Nineteen healthy volunteers were subjected to broadband white noise in a block paradigm; each run had four sound-on/off alternations and was repeated nine times for each subject. Sparse sampling (TR = 8 s) was used. In addition to traditional gray matter (GM) auditory center activation, WM activation was detected in the isthmus and midbody of the corpus callosum (CC), tapetum, auditory radiation, lateral lemniscus, and decussation of the superior cerebellar peduncles. At the individual level, 13 of 19 subjects (68 %) had CC activation. Callosal WM exhibited a temporal delay of approximately 8 s in response to the stimulation compared with GM. These findings suggest that direct evaluation of the entire functional network of the central auditory system may be possible using fMRI, which may aid in understanding the neurophysiological basis of the central auditory system and in developing treatment strategies for various central auditory disorders. (orig.)

  14. Auditory white noise reduces postural fluctuations even in the absence of vision.

    Science.gov (United States)

    Ross, Jessica Marie; Balasubramaniam, Ramesh

    2015-08-01

    The contributions of somatosensory, vestibular, and visual feedback to balance control are well documented, but the influence of auditory information, especially acoustic noise, on balance is less clear. Because somatosensory noise has been shown to reduce postural sway, we hypothesized that noise from the auditory modality might have a similar effect. Given that the nervous system uses noise to optimize signal transfer, adding mechanical or auditory noise should lead to increased feedback about sensory frames of reference used in balance control. In the present experiment, postural sway was analyzed in healthy young adults where they were presented with continuous white noise, in the presence and absence of visual information. Our results show reduced postural sway variability (as indexed by the body's center of pressure) in the presence of auditory noise, even when visual information was not present. Nonlinear time series analysis revealed that auditory noise has an additive effect, independent of vision, on postural stability. Further analysis revealed that auditory noise reduced postural sway variability in both low- and high-frequency regimes (> or noise. Our results support the idea that auditory white noise reduces postural sway, suggesting that auditory noise might be used for therapeutic and rehabilitation purposes in older individuals and those with balance disorders.

  15. Transponder-aided joint calibration and synchronization compensation for distributed radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2015-01-01

    High-precision radiometric calibration and synchronization compensation must be provided for distributed radar system due to separate transmitters and receivers. This paper proposes a transponder-aided joint radiometric calibration, motion compensation and synchronization for distributed radar remote sensing. As the transponder signal can be separated from the normal radar returns, it is used to calibrate the distributed radar for radiometry. Meanwhile, the distributed radar motion compensation and synchronization compensation algorithms are presented by utilizing the transponder signals. This method requires no hardware modifications to both the normal radar transmitter and receiver and no change to the operating pulse repetition frequency (PRF). The distributed radar radiometric calibration and synchronization compensation require only one transponder, but the motion compensation requires six transponders because there are six independent variables in the distributed radar geometry. Furthermore, a maximum likelihood method is used to estimate the transponder signal parameters. The proposed methods are verified by simulation results.

  16. Auditory short-term memory in the primate auditory cortex

    Science.gov (United States)

    Scott, Brian H.; Mishkin, Mortimer

    2015-01-01

    Sounds are fleeting, and assembling the sequence of inputs at the ear into a coherent percept requires auditory memory across various time scales. Auditory short-term memory comprises at least two components: an active ‘working memory’ bolstered by rehearsal, and a sensory trace that may be passively retained. Working memory relies on representations recalled from long-term memory, and their rehearsal may require phonological mechanisms unique to humans. The sensory component, passive short-term memory (pSTM), is tractable to study in nonhuman primates, whose brain architecture and behavioral repertoire are comparable to our own. This review discusses recent advances in the behavioral and neurophysiological study of auditory memory with a focus on single-unit recordings from macaque monkeys performing delayed-match-to-sample (DMS) tasks. Monkeys appear to employ pSTM to solve these tasks, as evidenced by the impact of interfering stimuli on memory performance. In several regards, pSTM in monkeys resembles pitch memory in humans, and may engage similar neural mechanisms. Neural correlates of DMS performance have been observed throughout the auditory and prefrontal cortex, defining a network of areas supporting auditory STM with parallels to that supporting visual STM. These correlates include persistent neural firing, or a suppression of firing, during the delay period of the memory task, as well as suppression or (less commonly) enhancement of sensory responses when a sound is repeated as a ‘match’ stimulus. Auditory STM is supported by a distributed temporo-frontal network in which sensitivity to stimulus history is an intrinsic feature of auditory processing. PMID:26541581

  17. Diminished auditory sensory gating during active auditory verbal hallucinations.

    Science.gov (United States)

    Thoma, Robert J; Meier, Andrew; Houck, Jon; Clark, Vincent P; Lewine, Jeffrey D; Turner, Jessica; Calhoun, Vince; Stephen, Julia

    2017-10-01

    Auditory sensory gating, assessed in a paired-click paradigm, indicates the extent to which incoming stimuli are filtered, or "gated", in auditory cortex. Gating is typically computed as the ratio of the peak amplitude of the event related potential (ERP) to a second click (S2) divided by the peak amplitude of the ERP to a first click (S1). Higher gating ratios are purportedly indicative of incomplete suppression of S2 and considered to represent sensory processing dysfunction. In schizophrenia, hallucination severity is positively correlated with gating ratios, and it was hypothesized that a failure of sensory control processes early in auditory sensation (gating) may represent a larger system failure within the auditory data stream; resulting in auditory verbal hallucinations (AVH). EEG data were collected while patients (N=12) with treatment-resistant AVH pressed a button to indicate the beginning (AVH-on) and end (AVH-off) of each AVH during a paired click protocol. For each participant, separate gating ratios were computed for the P50, N100, and P200 components for each of the AVH-off and AVH-on states. AVH trait severity was assessed using the Psychotic Symptoms Rating Scales AVH Total score (PSYRATS). The results of a mixed model ANOVA revealed an overall effect for AVH state, such that gating ratios were significantly higher during the AVH-on state than during AVH-off for all three components. PSYRATS score was significantly and negatively correlated with N100 gating ratio only in the AVH-off state. These findings link onset of AVH with a failure of an empirically-defined auditory inhibition system, auditory sensory gating, and pave the way for a sensory gating model of AVH. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Fiber laser master oscillators for optical synchronization systems

    International Nuclear Information System (INIS)

    Winter, A.

    2008-04-01

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  19. Global Positioning System Synchronized Active Light Autonomous Docking System

    Science.gov (United States)

    Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor); Bell, Joseph L. (Inventor)

    1996-01-01

    A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprising at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

  20. Information filtering by synchronous spikes in a neural population.

    Science.gov (United States)

    Sharafi, Nahal; Benda, Jan; Lindner, Benjamin

    2013-04-01

    Information about time-dependent sensory stimuli is encoded by the spike trains of neurons. Here we consider a population of uncoupled but noisy neurons (each subject to some intrinsic noise) that are driven by a common broadband signal. We ask specifically how much information is encoded in the synchronous activity of the population and how this information transfer is distributed with respect to frequency bands. In order to obtain some insight into the mechanism of information filtering effects found previously in the literature, we develop a mathematical framework to calculate the coherence of the synchronous output with the common stimulus for populations of simple neuron models. Within this frame, the synchronous activity is treated as the product of filtered versions of the spike trains of a subset of neurons. We compare our results for the simple cases of (1) a Poisson neuron with a rate modulation and (2) an LIF neuron with intrinsic white current noise and a current stimulus. For the Poisson neuron, formulas are particularly simple but show only a low-pass behavior of the coherence of synchronous activity. For the LIF model, in contrast, the coherence function of the synchronous activity shows a clear peak at high frequencies, comparable to recent experimental findings. We uncover the mechanism for this shift in the maximum of the coherence and discuss some biological implications of our findings.

  1. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  2. Selective Attention to Auditory Memory Neurally Enhances Perceptual Precision.

    Science.gov (United States)

    Lim, Sung-Joo; Wöstmann, Malte; Obleser, Jonas

    2015-12-09

    Selective attention to a task-relevant stimulus facilitates encoding of that stimulus into a working memory representation. It is less clear whether selective attention also improves the precision of a stimulus already represented in memory. Here, we investigate the behavioral and neural dynamics of selective attention to representations in auditory working memory (i.e., auditory objects) using psychophysical modeling and model-based analysis of electroencephalographic signals. Human listeners performed a syllable pitch discrimination task where two syllables served as to-be-encoded auditory objects. Valid (vs neutral) retroactive cues were presented during retention to allow listeners to selectively attend to the to-be-probed auditory object in memory. Behaviorally, listeners represented auditory objects in memory more precisely (expressed by steeper slopes of a psychometric curve) and made faster perceptual decisions when valid compared to neutral retrocues were presented. Neurally, valid compared to neutral retrocues elicited a larger frontocentral sustained negativity in the evoked potential as well as enhanced parietal alpha/low-beta oscillatory power (9-18 Hz) during memory retention. Critically, individual magnitudes of alpha oscillatory power (7-11 Hz) modulation predicted the degree to which valid retrocues benefitted individuals' behavior. Our results indicate that selective attention to a specific object in auditory memory does benefit human performance not by simply reducing memory load, but by actively engaging complementary neural resources to sharpen the precision of the task-relevant object in memory. Can selective attention improve the representational precision with which objects are held in memory? And if so, what are the neural mechanisms that support such improvement? These issues have been rarely examined within the auditory modality, in which acoustic signals change and vanish on a milliseconds time scale. Introducing a new auditory memory

  3. Salicylate-induced peripheral auditory changes and tonotopic reorganization of auditory cortex

    Science.gov (United States)

    Stolzberg, Daniel; Chen, Guang-Di; Allman, Brian L.; Salvi, Richard J.

    2011-01-01

    The neuronal mechanism underlying the phantom auditory perception of tinnitus remains at present elusive. For over 25 years, temporary tinnitus following acute salicylate intoxication in rats has been used as a model to understand how a phantom sound can be generated. Behavioral studies have indicated the pitch of salicylate-induced tinnitus in the rat is approximately 16 kHz. In order to better understand the origin of the tinnitus pitch, in the present study, measurements were made at the levels of auditory input and output; both cochlear and cortical physiological recordings were performed in ketamine/xylazine anesthetized rats. Both compound action potentials and distortion product otoacoustic emission measurements revealed a salicylate-induced band-pass-like cochlear deficit in which the reduction of cochlear input was least at 16 kHz and significantly greater at high and low frequencies. In a separate group of rats, frequency receptive fields of primary auditory cortex neurons were tracked using multichannel microelectrodes before and after systemic salicylate treatment. Tracking frequency receptive fields following salicylate revealed a population of neurons that shifted their frequency of maximum sensitivity (i.e., characteristic frequency) towards the tinnitus frequency region of the tonotopic axis (~16 kHz). The data presented here supports the hypothesis that salicylateinduced tinnitus results from an expanded cortical representation of the tinnitus pitch determined by an altered profile of input from the cochlea. Moreover, the pliability of cortical frequency receptive fields during salicylate-induced tinnitus is likely due to salicylate’s direct action on intracortical inhibitory networks. Such a disproportionate representation of middle frequencies in the auditory cortex following salicylate may result in a finer analysis of signals within this region which may pathologically enhance the functional importance of spurious neuronal activity

  4. Bodily Synchronization Underlying Joke Telling

    Directory of Open Access Journals (Sweden)

    R. C. Schmidt

    2014-08-01

    Full Text Available Advances in video and time series analysis have greatly enhanced our ability to study the bodily synchronization that occurs in natural interactions. Past research has demonstrated that the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. The present study investigated how the bodily synchronization in a joke telling task is spread across different nested temporal scales. Pairs of participants enacted knock-knock jokes and times series of their bodily activity were recorded. Coherence and relative phase analyses were used to evaluate the synchronization of bodily rhythms for the whole trial as well as at the subsidiary time scales of the whole joke, the setup of the punch line, the two-person exchange and the utterance. The analyses revealed greater than chance entrainment of the joke teller’s and joke responder’s movements at all time scales and that the relative phasing of the teller’s movements led those of the responder at the longer time scales. Moreover, this entrainment was greater when visual information about the partner’s movements was present but was decreased particularly at the shorter time scales when explicit gesturing in telling the joke was performed. In short, the results demonstrate that a complex interpersonal bodily dance occurs during structured conversation interactions and that this dance is constructed from a set of rhythms associated with the nested behavioral structure of the interaction.

  5. Spatiotemporal Relationships among Audiovisual Stimuli Modulate Auditory Facilitation of Visual Target Discrimination.

    Science.gov (United States)

    Li, Qi; Yang, Huamin; Sun, Fang; Wu, Jinglong

    2015-03-01

    Sensory information is multimodal; through audiovisual interaction, task-irrelevant auditory stimuli tend to speed response times and increase visual perception accuracy. However, mechanisms underlying these performance enhancements have remained unclear. We hypothesize that task-irrelevant auditory stimuli might provide reliable temporal and spatial cues for visual target discrimination and behavioral response enhancement. Using signal detection theory, the present study investigated the effects of spatiotemporal relationships on auditory facilitation of visual target discrimination. Three experiments were conducted where an auditory stimulus maintained reliable temporal and/or spatial relationships with visual target stimuli. Results showed that perception sensitivity (d') to visual target stimuli was enhanced only when a task-irrelevant auditory stimulus maintained reliable spatiotemporal relationships with a visual target stimulus. When only reliable spatial or temporal information was contained, perception sensitivity was not enhanced. These results suggest that reliable spatiotemporal relationships between visual and auditory signals are required for audiovisual integration during a visual discrimination task, most likely due to a spread of attention. These results also indicate that auditory facilitation of visual target discrimination follows from late-stage cognitive processes rather than early stage sensory processes. © 2015 SAGE Publications.

  6. [Information Processing in the Auditory Ventral Stream].

    Science.gov (United States)

    Fukushima, Makoto; Ojima, Hisayuki

    2016-11-01

    The auditory cortex in humans comprises multiple auditory fields organized hierarchically, similar to that in non-human primates. The ventral auditory stream of the macaque consists of several subdivisions on the supratemporal plane (STP) and the superior temporal gyrus (STG). There are two main axes (caudorostral and mediolateral) for processing auditory information in the STP and STG. Here, we review the neural basis of the integration of spectral and temporal auditory information along the two axes of the ventral auditory stream in the macaque.

  7. Active control strategy for synchronization and anti-synchronization of a fractional chaotic financial system

    Science.gov (United States)

    Huang, Chengdai; Cao, Jinde

    2017-05-01

    This paper is concerned with the issues of synchronization and anti-synchronization for fractional chaotic financial system with market confidence by taking advantage of active control approach. Some sufficient conditions are derived to guarantee the synchronization and anti-synchronization for the proposed fractional system. Moreover, the relationship between the order and synchronization(anti-synchronization) is demonstrated numerically. It reveals that synchronization(anti-synchronization) is faster as the order increases. Finally, two illustrative examples are exploited to verify the efficiency of the obtained theoretical results.

  8. Synchronization in uncertain complex networks.

    Science.gov (United States)

    Chen, Maoyin; Zhou, Donghua

    2006-03-01

    We consider the problem of synchronization in uncertain generic complex networks. For generic complex networks with unknown dynamics of nodes and unknown coupling functions including uniform and nonuniform inner couplings, some simple linear feedback controllers with updated strengths are designed using the well-known LaSalle invariance principle. The state of an uncertain generic complex network can synchronize an arbitrary assigned state of an isolated node of the network. The famous Lorenz system is stimulated as the nodes of the complex networks with different topologies. We found that the star coupled and scale-free networks with nonuniform inner couplings can be in the state of synchronization if only a fraction of nodes are controlled.

  9. Quantifying Neural Oscillatory Synchronization: A Comparison between Spectral Coherence and Phase-Locking Value Approaches.

    Science.gov (United States)

    Lowet, Eric; Roberts, Mark J; Bonizzi, Pietro; Karel, Joël; De Weerd, Peter

    2016-01-01

    Synchronization or phase-locking between oscillating neuronal groups is considered to be important for coordination of information among cortical networks. Spectral coherence is a commonly used approach to quantify phase locking between neural signals. We systematically explored the validity of spectral coherence measures for quantifying synchronization among neural oscillators. To that aim, we simulated coupled oscillatory signals that exhibited synchronization dynamics using an abstract phase-oscillator model as well as interacting gamma-generating spiking neural networks. We found that, within a large parameter range, the spectral coherence measure deviated substantially from the expected phase-locking. Moreover, spectral coherence did not converge to the expected value with increasing signal-to-noise ratio. We found that spectral coherence particularly failed when oscillators were in the partially (intermittent) synchronized state, which we expect to be the most likely state for neural synchronization. The failure was due to the fast frequency and amplitude changes induced by synchronization forces. We then investigated whether spectral coherence reflected the information flow among networks measured by transfer entropy (TE) of spike trains. We found that spectral coherence failed to robustly reflect changes in synchrony-mediated information flow between neural networks in many instances. As an alternative approach we explored a phase-locking value (PLV) method based on the reconstruction of the instantaneous phase. As one approach for reconstructing instantaneous phase, we used the Hilbert Transform (HT) preceded by Singular Spectrum Decomposition (SSD) of the signal. PLV estimates have broad applicability as they do not rely on stationarity, and, unlike spectral coherence, they enable more accurate estimations of oscillatory synchronization across a wide range of different synchronization regimes, and better tracking of synchronization-mediated information

  10. Optical Synchronization Systems for Femtosecond X-Ray Sources

    CERN Document Server

    Wilcox, Russell; Staples, John W

    2005-01-01

    In femtosecond pump/probe experiments using short x-ray and optical pulses, precise synchronization must be maintained between widely separated lasers in a synchrotron or FEL facility. We are developing synchronization systems using optical signals for applications requiring different ranges of timing error. For the sub-100fs range we use an amplitude modulated CW laser at 1GHz to transmit RF phase information, and control the delay through a 100m fiber by observing the retroreflected signal. Initial results show 40fs peak-to-peak error above 10Hz, and 200fs long term drift, mainly due to amplitude sensitivity in the analog mixers. For the sub-10fs range we will lock two single-frequency lasers separated by several teraHertz to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes. For attosecond synchronization we propose a stabilized, free space link using bulk lens wavegu...

  11. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  12. A synchronous game for binary constraint systems

    Science.gov (United States)

    Kim, Se-Jin; Paulsen, Vern; Schafhauser, Christopher

    2018-03-01

    Recently, Slofstra proved that the set of quantum correlations is not closed. We prove that the set of synchronous quantum correlations is not closed, which implies his result, by giving an example of a synchronous game that has a perfect quantum approximate strategy but no perfect quantum strategy. We also exhibit a graph for which the quantum independence number and the quantum approximate independence number are different. We prove new characterisations of synchronous quantum approximate correlations and synchronous quantum spatial correlations. We solve the synchronous approximation problem of Dykema and the second author, which yields a new equivalence of Connes' embedding problem in terms of synchronous correlations.

  13. MODELING SPECTRAL AND TEMPORAL MASKING IN THE HUMAN AUDITORY SYSTEM

    DEFF Research Database (Denmark)

    Dau, Torsten; Jepsen, Morten Løve; Ewert, Stephan D.

    2007-01-01

    An auditory signal processing model is presented that simulates psychoacoustical data from a large variety of experimental conditions related to spectral and temporal masking. The model is based on the modulation filterbank model by Dau et al. [J. Acoust. Soc. Am. 102, 2892-2905 (1997)] but inclu......An auditory signal processing model is presented that simulates psychoacoustical data from a large variety of experimental conditions related to spectral and temporal masking. The model is based on the modulation filterbank model by Dau et al. [J. Acoust. Soc. Am. 102, 2892-2905 (1997...... was tested in conditions of tone-in-noise masking, intensity discrimination, spectral masking with tones and narrowband noises, forward masking with (on- and off-frequency) noise- and pure-tone maskers, and amplitude modulation detection using different noise carrier bandwidths. One of the key properties...

  14. Electrically-evoked frequency-following response (EFFR in the auditory brainstem of guinea pigs.

    Directory of Open Access Journals (Sweden)

    Wenxin He

    Full Text Available It is still a difficult clinical issue to decide whether a patient is a suitable candidate for a cochlear implant and to plan postoperative rehabilitation, especially for some special cases, such as auditory neuropathy. A partial solution to these problems is to preoperatively evaluate the functional integrity of the auditory neural pathways. For evaluating the strength of phase-locking of auditory neurons, which was not reflected in previous methods using electrically evoked auditory brainstem response (EABR, a new method for recording phase-locking related auditory responses to electrical stimulation, called the electrically evoked frequency-following response (EFFR, was developed and evaluated using guinea pigs. The main objective was to assess feasibility of the method by testing whether the recorded signals reflected auditory neural responses or artifacts. The results showed the following: 1 the recorded signals were evoked by neuron responses rather than by artifact; 2 responses evoked by periodic signals were significantly higher than those evoked by the white noise; 3 the latency of the responses fell in the expected range; 4 the responses decreased significantly after death of the guinea pigs; and 5 the responses decreased significantly when the animal was replaced by an electrical resistance. All of these results suggest the method was valid. Recording obtained using complex tones with a missing fundamental component and using pure tones with various frequencies were consistent with those obtained using acoustic stimulation in previous studies.

  15. Effects of STN DBS and auditory cueing on the performance of sequential movements and the occurrence of action tremor in Parkinson’s disease

    NARCIS (Netherlands)

    Heida, Tjitske; Wentink, E.C.; Zhao, Yan; Marani, Enrico

    2014-01-01

    Background: Parkinson’s disease (PD) patients show a higher ability to perform repetitive movements when they are cued by external stimuli, suggesting that rhythmic synchronization with an auditory timekeeper can be achieved in the absence of intact basal ganglia function. Deep brain stimulation

  16. Amplitude modulation rate dependent topographic organization of the auditory steady-state response in human auditory cortex.

    Science.gov (United States)

    Weisz, Nathan; Lithari, Chrysoula

    2017-10-01

    Periodic modulations of an acoustic feature, such as amplitude over a certain frequency range, leads to phase locking of neural responses to the envelope of the modulation. Using electrophysiological methods this neural activity pattern, also called the auditory steady-state response (aSSR), is visible following frequency transformation of the evoked response as a clear spectral peak at the modulation frequency. Despite several studies employing the aSSR that show, for example, strongest responses for ∼40 Hz and an overall right-hemispheric dominance, it has not been investigated so far to what extent within auditory cortex different modulation frequencies elicit aSSRs at a homogenous source or whether the localization of the aSSR is topographically organized in a systematic manner. The latter would be suggested by previous neuroimaging works in monkeys and humans showing a periodotopic organization within and across distinct auditory fields. However, the sluggishness of the signal from these neuroimaging works prohibit inferences with regards to the fine-temporal features of the neural response. In the present study, we employed amplitude-modulated (AM) sounds over a range between 4 and 85 Hz to elicit aSSRs while recording brain activity via magnetoencephalography (MEG). Using beamforming and a fine spatially resolved grid restricted to auditory cortical processing regions, our study revealed a topographic representation of the aSSR that depends on AM rate, in particular in the medial-lateral (bilateral) and posterior-anterior (right auditory cortex) direction. In summary, our findings confirm previous studies that showing different AM rates to elicit maximal response in distinct neural populations. They extend these findings however by also showing that these respective neural ensembles in auditory cortex actually phase lock their activity over a wide modulation frequency range. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Synchronization of Switched Neural Networks With Communication Delays via the Event-Triggered Control.

    Science.gov (United States)

    Wen, Shiping; Zeng, Zhigang; Chen, Michael Z Q; Huang, Tingwen

    2017-10-01

    This paper addresses the issue of synchronization of switched delayed neural networks with communication delays via event-triggered control. For synchronizing coupled switched neural networks, we propose a novel event-triggered control law which could greatly reduce the number of control updates for synchronization tasks of coupled switched neural networks involving embedded microprocessors with limited on-board resources. The control signals are driven by properly defined events, which depend on the measurement errors and current-sampled states. By using a delay system method, a novel model of synchronization error system with delays is proposed with the communication delays and event-triggered control in the unified framework for coupled switched neural networks. The criteria are derived for the event-triggered synchronization analysis and control synthesis of switched neural networks via the Lyapunov-Krasovskii functional method and free weighting matrix approach. A numerical example is elaborated on to illustrate the effectiveness of the derived results.

  18. Synchronous spikes are necessary but not sufficient for a synchrony code in populations of spiking neurons.

    Science.gov (United States)

    Grewe, Jan; Kruscha, Alexandra; Lindner, Benjamin; Benda, Jan

    2017-03-07

    Synchronous activity in populations of neurons potentially encodes special stimulus features. Selective readout of either synchronous or asynchronous activity allows formation of two streams of information processing. Theoretical work predicts that such a synchrony code is a fundamental feature of populations of spiking neurons if they operate in specific noise and stimulus regimes. Here we experimentally test the theoretical predictions by quantifying and comparing neuronal response properties in tuberous and ampullary electroreceptor afferents of the weakly electric fish Apteronotus leptorhynchus These related systems show similar levels of synchronous activity, but only in the more irregularly firing tuberous afferents a synchrony code is established, whereas in the more regularly firing ampullary afferents it is not. The mere existence of synchronous activity is thus not sufficient for a synchrony code. Single-cell features such as the irregularity of spiking and the frequency dependence of the neuron's transfer function determine whether synchronous spikes possess a distinct meaning for the encoding of time-dependent signals.

  19. Synchronization and Timing in CMS HCAL

    CERN Document Server

    Baiatian, G; Emeliantchik, Igor; Massolov, V; Shumeiko, Nikolai; Stefanovich, R; Damgov, Jordan; Dimitrov, Lubomir; Genchev, Vladimir; Piperov, Stefan; Vankov, Ivan; Litov, Leander; Bencze, Gyorgy; Laszlo, Andras; Pal, Andras; Vesztergombi, Gyorgy; Zálán, Peter; Fenyvesi, Andras; Bawa, Harinder Singh; Beri, Suman Bala; Bhatnagar, Vipin; Kaur, Manjit; Kohli, Jatinder Mohan; Kumar, Arun; Singh, Jas Bir; Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Chendvankar, Sanjay; Dugad, Shashikant; Kalmani, Suresh Devendrappa; Katta, S; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Patil, Mandakini Ravindra; Reddy, L; Satyanarayana, B; Sharma, Seema; Sudhakar, Katta; Verma, Piyush; Hashemi, Majid; Mohammadi-Najafabadi, M; Paktinat, S; Golutvin, Igor; Kalagin, Vladimir; Kosarev, Ivan; Ladygin, Vladimir; Mescheryakov, G; Moissenz, P; Petrosian, A; Sergeyev, S; Smirnov, Vitaly; Vishnevskiy, Alexander; Volodko, Anton; Zarubin, Anatoli; Gavrilov, Vladimir; Gershtein, Yuri; Ilyina, N; Kaftanov, Vitali; Kisselevich, I; Kolossov, V; Krokhotin, Andrey; Kuleshov, Sergey; Litvintsev, Dmitri; Ulyanov, A; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Demianov, A; Gribushin, Andrey; Kodolova, Olga; Petrushanko, Sergey; Sarycheva, Ludmila; Teplov, V; Vardanyan, Irina; Yershov, A; Abramov, Victor; Goncharov, Petr; Kalinin, Alexey; Khmelnikov, Alexander; Korablev, Andrey; Korneev, Yury; Krinitsyn, Alexander; Kryshkin, V; Lukanin, Vladimir; Pikalov, Vladimir; Ryazanov, Anton; Talov, Vladimir; Turchanovich, L; Volkov, Alexey; Camporesi, Tiziano; De Visser, Theo; Vlassov, E; Aydin, Sezgin; Bakirci, Mustafa Numan; Cerci, Salim; Dumanoglu, Isa; Eskut, Eda; Kayis-Topaksu, A; Koylu, S; Kurt, Pelin; Onengüt, G; Ozkurt, Halil; Polatoz, A; Sogut, Kenan; Topakli, Huseyin; Vergili, Mehmet; Yetkin, Taylan; Cankocak, Kerem; Esendemir, Akif; Gamsizkan, Halil; Güler, M; Ozkan, Cigdem; Sekmen, Sezen; Serin-Zeyrek, M; Sever, Ramazan; Yazgan, Efe; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Gülmez, Erhan; Isiksal, Engin; Kaya, Mithat; Ozkorucuklu, Suat; Levchuk, Leonid; Sorokin, Pavel; Senchyshyn, Vitaliy; Hauptman, John M; Abdullin, Salavat; Elias, John E; Elvira, D; Freeman, Jim; Green, Dan; Los, Serguei; O'Dell, Vivian; Ronzhin, Anatoly; Suzuki, Ichiro; Vidal, Richard; Whitmore, Juliana; Arcidy, M; Hazen, Eric; Heering, Arjan Hendrix; Lawlor, C; Lazic, Dragoslav; Machado, Emanuel; Rohlf, James; Varela, F; Wu, Shouxiang; Baden, Drew; Bard, Robert; Eno, Sarah Catherine; Grassi, Tullio; Jarvis, Chad; Kellogg, Richard G; Kunori, Shuichi; Mans, Jeremy; Skuja, Andris; Podrasky, V; Sanzeni, Christopher; Winn, Dave; Akgun, Ugur; Ayan, S; Duru, Firdevs; Merlo, Jean-Pierre; Mestvirishvili, Alexi; Miller, Michael; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Schmidt, Ianos; Akchurin, Nural; Carrell, Kenneth Wayne; Gumus, Kazim; Kim, Heejong; Spezziga, Mario; Thomas, Ray; Wigmans, Richard; Baarmand, Marc M; Mermerkaya, Hamit; Ralich, Robert; Vodopiyanov, Igor; Kramer, Laird; Linn, Stephan; Markowitz, Pete; Cushman, Priscilla; Ma, Yousi; Sherwood, Brian; Cremaldi, Lucien Marcus; Reidy, Jim; Sanders, David A; Karmgard, Daniel John; Ruchti, Randy; Fisher, Wade Cameron; Tully, Christopher; Bodek, Arie; De Barbaro, Pawel; Budd, Howard; Chung, Yeon Sei; Haelen, T; Hagopian, Sharon; Hagopian, Vasken; Johnson, K; Barnes, Virgil E; Laasanen, Alvin T

    2006-01-01

    The synchronization and timing of the hadron calorimeter (HCAL) for the Compact Muon Solenoid has been extensively studied with test beams at CERN during the period 2003-4, including runs with 40 MHz structured beam. The relative phases of the signals from different calorimeter segments are timed to 1 ns accuracy using a laser and equalized using programmable delay settings in the front-end electronics. The beam was used to verify the timing and to map out the entire range of pulse shapes over the 25 ns interval between beam crossings. These data were used to make detailed measurements of energy-dependent time slewing effects and to tune the electronics for optimal performance.

  20. Multisensory integration of dynamic faces and voices in rhesus monkey auditory cortex.

    Science.gov (United States)

    Ghazanfar, Asif A; Maier, Joost X; Hoffman, Kari L; Logothetis, Nikos K

    2005-05-18

    In the social world, multiple sensory channels are used concurrently to facilitate communication. Among human and nonhuman primates, faces and voices are the primary means of transmitting social signals (Adolphs, 2003; Ghazanfar and Santos, 2004). Primates recognize the correspondence between species-specific facial and vocal expressions (Massaro, 1998; Ghazanfar and Logothetis, 2003; Izumi and Kojima, 2004), and these visual and auditory channels can be integrated into unified percepts to enhance detection and discrimination. Where and how such communication signals are integrated at the neural level are poorly understood. In particular, it is unclear what role "unimodal" sensory areas, such as the auditory cortex, may play. We recorded local field potential activity, the signal that best correlates with human imaging and event-related potential signals, in both the core and lateral belt regions of the auditory cortex in awake behaving rhesus monkeys while they viewed vocalizing conspecifics. We demonstrate unequivocally that the primate auditory cortex integrates facial and vocal signals through enhancement and suppression of field potentials in both the core and lateral belt regions. The majority of these multisensory responses were specific to face/voice integration, and the lateral belt region shows a greater frequency of multisensory integration than the core region. These multisensory processes in the auditory cortex likely occur via reciprocal interactions with the superior temporal sulcus.

  1. Predicting the biological variability of environmental rhythms: weak or strong anticipation for sensorimotor synchronization?

    Science.gov (United States)

    Torre, Kjerstin; Varlet, Manuel; Marmelat, Vivien

    2013-12-01

    The internal processes involved in synchronizing our movements with environmental stimuli have traditionally been addressed using regular metronomic sequences. Regarding real-life environments, however, biological rhythms are known to have intrinsic variability, ubiquitously characterized as fractal long-range correlations. In our research we thus investigate to what extent the synchronization processes drawn from regular metronome paradigms can be generalized to other (biologically) variable rhythms. Participants performed synchronized finger tapping under five conditions of long-range and/or short-range correlated, randomly variable, and regular auditory sequences. Combining experimental data analysis and numerical simulation, we found that synchronizing with biologically variable rhythms involves the same internal processes as with other variable rhythms (whether totally random or comprising lawful regularities), but different from those involved with a regular metronome. This challenges both the generalizability of conclusions drawn from regular-metronome paradigms, and recent research assuming that biologically variable rhythms may trigger specific strong anticipatory processes to achieve synchronization. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Children's auditory working memory performance in degraded listening conditions.

    Science.gov (United States)

    Osman, Homira; Sullivan, Jessica R

    2014-08-01

    The objectives of this study were to determine (a) whether school-age children with typical hearing demonstrate poorer auditory working memory performance in multitalker babble at degraded signal-to-noise ratios than in quiet; and (b) whether the amount of cognitive demand of the task contributed to differences in performance in noise. It was hypothesized that stressing the working memory system with the presence of noise would impede working memory processes in real time and result in poorer working memory performance in degraded conditions. Twenty children with typical hearing between 8 and 10 years old were tested using 4 auditory working memory tasks (Forward Digit Recall, Backward Digit Recall, Listening Recall Primary, and Listening Recall Secondary). Stimuli were from the standardized Working Memory Test Battery for Children. Each task was administered in quiet and in 4-talker babble noise at 0 dB and -5 dB signal-to-noise ratios. Children's auditory working memory performance was systematically decreased in the presence of multitalker babble noise compared with quiet. Differences between low-complexity and high-complexity tasks were observed, with children performing more poorly on tasks with greater storage and processing demands. There was no interaction between noise and complexity of task. All tasks were negatively impacted similarly by the addition of noise. Auditory working memory performance was negatively impacted by the presence of multitalker babble noise. Regardless of complexity of task, noise had a similar effect on performance. These findings suggest that the addition of noise inhibits auditory working memory processes in real time for school-age children.

  3. Memorable Audiovisual Narratives Synchronize Sensory and Supramodal Neural Responses

    Science.gov (United States)

    2016-01-01

    Abstract Our brains integrate information across sensory modalities to generate perceptual experiences and form memories. However, it is difficult to determine the conditions under which multisensory stimulation will benefit or hinder the retrieval of everyday experiences. We hypothesized that the determining factor is the reliability of information processing during stimulus presentation, which can be measured through intersubject correlation of stimulus-evoked activity. We therefore presented biographical auditory narratives and visual animations to 72 human subjects visually, auditorily, or combined, while neural activity was recorded using electroencephalography. Memory for the narrated information, contained in the auditory stream, was tested 3 weeks later. While the visual stimulus alone led to no meaningful retrieval, this related stimulus improved memory when it was combined with the story, even when it was temporally incongruent with the audio. Further, individuals with better subsequent memory elicited neural responses during encoding that were more correlated with their peers. Surprisingly, portions of this predictive synchronized activity were present regardless of the sensory modality of the stimulus. These data suggest that the strength of sensory and supramodal activity is predictive of memory performance after 3 weeks, and that neural synchrony may explain the mnemonic benefit of the functionally uninformative visual context observed for these real-world stimuli. PMID:27844062

  4. Biological impact of music and software-based auditory training

    OpenAIRE

    Kraus, Nina

    2012-01-01

    Auditory-based communication skills are developed at a young age and are maintained throughout our lives. However, some individuals – both young and old – encounter difficulties in achieving or maintaining communication proficiency. Biological signals arising from hearing sounds relate to real-life communication skills such as listening to speech in noisy environments and reading, pointing to an intersection between hearing and cognition. Musical experience, amplification, and software-based ...

  5. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...... by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs....

  6. Auditory Neuropathy Spectrum Disorder (ANSD) (For Parents)

    Science.gov (United States)

    ... Videos for Educators Search English Español Auditory Neuropathy Spectrum Disorder (ANSD) KidsHealth / For Parents / Auditory Neuropathy Spectrum ... is done while the child is sleeping. Otoacoustic emission (OAE): This test measures how well the outer ...

  7. Encoding by synchronization in the primate striatum.

    Science.gov (United States)

    Adler, Avital; Finkes, Inna; Katabi, Shiran; Prut, Yifat; Bergman, Hagai

    2013-03-13

    Information is encoded in the nervous system through the discharge and synchronization of single neurons. The striatum, the input stage of the basal ganglia, is divided into three territories: the putamen, the caudate, and the ventral striatum, all of which converge onto the same motor pathway. This parallel organization suggests that there are multiple and competing systems in the basal ganglia network controlling behavior. To explore which mechanism(s) enables the different striatal domains to encode behavioral events and to control behavior, we compared the neural activity of phasically active neurons [medium spiny neurons (MSNs), presumed projection neurons] and tonically active neurons (presumed cholinergic interneurons) across striatal territories from monkeys during the performance of a well practiced task. Although neurons in all striatal territories displayed similar spontaneous discharge properties and similar temporal modulations of their discharge rates to the behavioral events, their correlation structure was profoundly different. The distributions of signal and noise correlation of pairs of putamen MSNs were strongly shifted toward positive correlations and these two measures were correlated. In contrast, MSN pairs in the caudate and ventral striatum displayed symmetrical, near-zero signal and noise correlation distributions. Furthermore, only putamen MSN pairs displayed different noise correlation dynamics to rewarding versus neutral/aversive cues. Similarly, the noise correlation between tonically active neuron pairs was stronger in the putamen than in the caudate. We suggest that the level of synchronization of the neuronal activity and its temporal dynamics differentiate the striatal territories and may thus account for the different roles that striatal domains play in behavioral control.

  8. Modelling of intercellular synchronization in the Drosophila circadian clock

    International Nuclear Information System (INIS)

    Jun-Wei, Wang; Ai-Min, Chen; Jia-Jun, Zhang; Zhan-Jiang, Yuan; Tian-Shou, Zhou

    2009-01-01

    In circadian rhythm generation, intercellular signaling factors are shown to play a crucial role in both sustaining intrinsic cellular rhythmicity and acquiring collective behaviours across a population of circadian neurons. However, the physical mechanism behind their role remains to be fully understood. In this paper, we propose an indirectly coupled multicellular model for the synchronization of Drosophila circadian oscillators combining both intracellular and intercellular dynamics. By simulating different experimental conditions, we find that such an indirect coupling way can synchronize both heterogeneous self-sustained circadian neurons and heterogeneous mutational damped circadian neurons. Moreover, they can also be entrained to ambient light-dark (LD) cycles depending on intercellular signaling. (cross-disciplinary physics and related areas of science and technology)

  9. Synchronizing Strategies under Partial Observability

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Laursen, Simon; Srba, Jiri

    2014-01-01

    Embedded devices usually share only partial information about their current configurations as the communication bandwidth can be restricted. Despite this, we may wish to bring a failed device into a given predetermined configuration. This problem, also known as resetting or synchronizing words, has...

  10. Synchronizing Web Documents with Style

    NARCIS (Netherlands)

    R.L. Guimarães (Rodrigo); D.C.A. Bulterman (Dick); P.S. Cesar Garcia (Pablo Santiago); A.J. Jansen (Jack)

    2014-01-01

    htmlabstractIn this paper we report on our efforts to define a set of document extensions to Cascading Style Sheets (CSS) that allow for structured timing and synchronization of elements within a Web page. Our work considers the scenario in which the temporal structure can be decoupled from the

  11. Learning through synchronous electronic discussion

    NARCIS (Netherlands)

    Kanselaar, G.; Veerman, A.L.; Andriessen, J.E.B.

    2000-01-01

    This article reports a study examining university student pairs carrying out an electronic discussion task in a synchronous computer mediated communication (CMC) system (NetMeeting). The purpose of the assignment was to raise students' awareness concerning conceptions that characterise effective

  12. OVULATORY RESFONSE IN PROGESTERONE SYNCHRONIZED ...

    African Journals Online (AJOL)

    Conception rate and ovarian function following estrus control by progestetone injections in dairy cattle. J. Anim. Sci. 14, 224. VAN NIEKERK, C.H., BELONJE, P.C. & SPREETH, E.B., 1970. Post partum synchronization of the oestrus period of lactating friesland cows with 6-methyl-17-acetozy-Progesterone. (MAP) and PMSG.

  13. Sports Medicine Meets Synchronized Swimming.

    Science.gov (United States)

    Wenz, Betty J.; And Others

    This collection of articles contains information about synchronized swimming. Topics covered include general physiology and cardiovascular conditioning, flexibility exercises, body composition, strength training, nutrition, coach-athlete relationships, coping with competition stress and performance anxiety, and eye care. Chapters are included on…

  14. Generalized synchronization via impulsive control

    International Nuclear Information System (INIS)

    Zhang Rong; Xu Zhenyuan; Yang, Simon X.; He Xueming

    2008-01-01

    This paper demonstrates theoretically that two completely different systems can implement GS via impulsive control, moreover by using impulsive control, for a given manifold y = H(x) we construct a response system to achieve GS with drive system and the synchronization manifold is y = H(x). Our theoretical results are supported by numerical examples

  15. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination...... as an infinite-dimensional optimal controlproblem. Illustrative numerical examples are given and commented....

  16. Synchronized whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    An attempt has been made to explain the dynamic spectra using lightning discharge generated from magnetospheric sources. Keywords. Whistler-mode wave propagation; dispersion; synchronized whistler. PACS No. 94.20.Mm. It is well-known that electromagnetic waves in wide frequency range are associated with.

  17. Fermi Timing and Synchronization System

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F.X.; Kim, J.; Chen, J.; Ilday, F.O.; Ludwig, F.; Winter, A.; Ferianis, M.; Danailov, M.; D' Auria, G.

    2006-07-19

    The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.

  18. Digital device for synchronous storage

    International Nuclear Information System (INIS)

    Kobzar', Yu.M.; Kovtun, V.G.; Pashechko, N.I.

    1991-01-01

    Synchronous storage digital device for IR electron-photon emission spectrometer operating with analogue-to-digital converter F4223 or monocrystal converter K572PV1 is described. The device accomplished deduction of noise-background in each storage cycle. Summation and deduction operational time equals 90 ns, device output code discharge - 20, number of storages -2 23

  19. Auditory Hallucinations in Acute Stroke

    Directory of Open Access Journals (Sweden)

    Yair Lampl

    2005-01-01

    Full Text Available Auditory hallucinations are uncommon phenomena which can be directly caused by acute stroke, mostly described after lesions of the brain stem, very rarely reported after cortical strokes. The purpose of this study is to determine the frequency of this phenomenon. In a cross sectional study, 641 stroke patients were followed in the period between 1996–2000. Each patient underwent comprehensive investigation and follow-up. Four patients were found to have post cortical stroke auditory hallucinations. All of them occurred after an ischemic lesion of the right temporal lobe. After no more than four months, all patients were symptom-free and without therapy. The fact the auditory hallucinations may be of cortical origin must be taken into consideration in the treatment of stroke patients. The phenomenon may be completely reversible after a couple of months.

  20. Integrated Time and Phase Synchronization Strategy for a Multichannel Spaceborne-Stationary Bistatic SAR System

    Directory of Open Access Journals (Sweden)

    Feng Hong

    2016-07-01

    Full Text Available The spatial separation of the transmitter and receiver in Bistatic Synthetic Aperture Radar (BiSAR makes it a promising and useful supplement to a classical Monostatic SAR system (MonoSAR. This paper proposes a novel integrated time and phase synchronization strategy for a multichannel spaceborne-stationary BiSAR system. Firstly, the time synchronization strategy is proposed, which includes Pulse Repetition Frequency (PRF generation under noisy conditions, multichannel calibration and the alignment of the recorded data with the orbital data. Furthermore, the phase synchronization strategy, which fully considers the deteriorative factors in the BiSAR configuration, is well studied. The contribution of the phase synchronization strategy includes two aspects: it not only compensates the phase error, but also improves the Signal to Noise Ratio (SNR of the obtained signals. Specifically, all direct signals on different PRF time can be reconstructed with the shift and phase compensation operation using a reference signal. Besides, since the parameters of the reference signal can be estimated only once using the selected practical direct signal and a priori information, the processing complexity is well reduced. Final imaging results with and without compensation for real data are presented to validate the proposed synchronization strategy.

  1. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du

    2015-01-01

    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  2. Synchronization of linear systems via relative actuation

    OpenAIRE

    Tuna, S. Emre

    2016-01-01

    Synchronization in networks of discrete-time linear time-invariant systems is considered under relative actuation. Neither input nor output matrices are assumed to be commensurable. A distributed algorithm that ensures synchronization via dynamic relative output feedback is presented.

  3. Biomimetic Sonar for Electrical Activation of the Auditory Pathway

    Directory of Open Access Journals (Sweden)

    D. Menniti

    2017-01-01

    Full Text Available Relying on the mechanism of bat’s echolocation system, a bioinspired electronic device has been developed to investigate the cortical activity of mammals in response to auditory sensorial stimuli. By means of implanted electrodes, acoustical information about the external environment generated by a biomimetic system and converted in electrical signals was delivered to anatomically selected structures of the auditory pathway. Electrocorticographic recordings showed that cerebral activity response is highly dependent on the information carried out by ultrasounds and is frequency-locked with the signal repetition rate. Frequency analysis reveals that delta and beta rhythm content increases, suggesting that sensorial information is successfully transferred and integrated. In addition, principal component analysis highlights how all the stimuli generate patterns of neural activity which can be clearly classified. The results show that brain response is modulated by echo signal features suggesting that spatial information sent by biomimetic sonar is efficiently interpreted and encoded by the auditory system. Consequently, these results give new perspective in artificial environmental perception, which could be used for developing new techniques useful in treating pathological conditions or influencing our perception of the surroundings.

  4. Plasticity in neuromagnetic cortical responses suggests enhanced auditory object representation.

    Science.gov (United States)

    Ross, Bernhard; Jamali, Shahab; Tremblay, Kelly L

    2013-12-05

    Auditory perceptual learning persistently modifies neural networks in the central nervous system. Central auditory processing comprises a hierarchy of sound analysis and integration, which transforms an acoustical signal into a meaningful object for perception. Based on latencies and source locations of auditory evoked responses, we investigated which stage of central processing undergoes neuroplastic changes when gaining auditory experience during passive listening and active perceptual training. Young healthy volunteers participated in a five-day training program to identify two pre-voiced versions of the stop-consonant syllable 'ba', which is an unusual speech sound to English listeners. Magnetoencephalographic (MEG) brain responses were recorded during two pre-training and one post-training sessions. Underlying cortical sources were localized, and the temporal dynamics of auditory evoked responses were analyzed. After both passive listening and active training, the amplitude of the P2m wave with latency of 200 ms increased considerably. By this latency, the integration of stimulus features into an auditory object for further conscious perception is considered to be complete. Therefore the P2m changes were discussed in the light of auditory object representation. Moreover, P2m sources were localized in anterior auditory association cortex, which is part of the antero-ventral pathway for object identification. The amplitude of the earlier N1m wave, which is related to processing of sensory information, did not change over the time course of the study. The P2m amplitude increase and its persistence over time constitute a neuroplastic change. The P2m gain likely reflects enhanced object representation after stimulus experience and training, which enables listeners to improve their ability for scrutinizing fine differences in pre-voicing time. Different trajectories of brain and behaviour changes suggest that the preceding effect of a P2m increase relates to brain

  5. Clock Synchronization Through Time-Variant Underwater Acoustic Channels

    Science.gov (United States)

    2012-09-01

    Pulse Interval SPI Synchronizing Pulse Interval LFM Linear Frequency - Modulated PDF Probability Density Function... frequency - modulated (LFM) chirp trains and pseudorandom (PRN) binary sequences as the most suitable types of probe signals. A key attribute of LFM and PRN...Reference Clock (B) Synchroni zing Clock (A) x x x x b Reference Pulse Interval (RPI) Synchroni zation Pul se Interval (SPI) 1 2 i n...... A y y y

  6. Inter-Symbol Guard Time for Synchronizing Optical PPM

    Science.gov (United States)

    Far, William; Gin, Jonathan; Srinivasan, Meera; Quirk, Kevin

    2009-01-01

    An inter-symbol guard time has been proposed as a means of synchronizing the symbol and slot clocks of an optical pulse-position modulation (PPM) receiver with the symbol and slot periods of an incoming optical PPM signal.The proposal is applicable to the low-flux case in which the receiver photodetector operates in a photon-counting mode and the count can include contributions from incidental light sources and dark current.

  7. Altered Sensory Feedbacks in Pianist's Dystonia: the altered auditory feedback paradigm and the glove effect

    Directory of Open Access Journals (Sweden)

    Felicia Pei-Hsin Cheng

    2013-12-01

    Full Text Available Background: This study investigates the effect of altered auditory feedback (AAF in musician's dystonia (MD and discusses whether altered auditory feedback can be considered as a sensory trick in MD. Furthermore, the effect of AAF is compared with altered tactile feedback, which can serve as a sensory trick in several other forms of focal dystonia. Methods: The method is based on scale analysis (Jabusch et al. 2004. Experiment 1 employs synchronization paradigm: 12 MD patients and 25 healthy pianists had to repeatedly play C-major scales in synchrony with a metronome on a MIDI-piano with 3 auditory feedback conditions: 1. normal feedback; 2. no feedback; 3. constant delayed feedback. Experiment 2 employs synchronization-continuation paradigm: 12 MD patients and 12 healthy pianists had to repeatedly play C-major scales in two phases: first in synchrony with a metronome, secondly continue the established tempo without the metronome. There are 4 experimental conditions, among them 3 are the same altered auditory feedback as in Experiment 1 and 1 is related to altered tactile sensory input. The coefficient of variation of inter-onset intervals of the key depressions was calculated to evaluate fine motor control. Results: In both experiments, the healthy controls and the patients behaved very similarly. There is no difference in the regularity of playing between the two groups under any condition, and neither did AAF nor did altered tactile feedback have a beneficial effect on patients’ fine motor control. Conclusions: The results of the two experiments suggest that in the context of our experimental designs, AAF and altered tactile feedback play a minor role in motor coordination in patients with musicians' dystonia. We propose that altered auditory and tactile feedback do not serve as effective sensory tricks and may not temporarily reduce the symptoms of patients suffering from MD in this experimental context.

  8. The Relationship between Types of Attention and Auditory Processing Skills: Reconsidering Auditory Processing Disorder Diagnosis

    OpenAIRE

    Stavrinos, Georgios; Iliadou, Vassiliki-Maria; Edwards, Lindsey; Sirimanna, Tony; Bamiou, Doris-Eva

    2018-01-01

    Measures of attention have been found to correlate with specific auditory processing tests in samples of children suspected of Auditory Processing Disorder (APD), but these relationships have not been adequately investigated. Despite evidence linking auditory attention and deficits/symptoms of APD, measures of attention are not routinely used in APD diagnostic protocols. The aim of the study was to examine the relationship between auditory and visual attention tests and auditory processing te...

  9. Auditory processing efficiency deficits in children with developmental language impairments

    Science.gov (United States)

    Hartley, Douglas E. H.; Moore, David R.

    2002-12-01

    The ``temporal processing hypothesis'' suggests that individuals with specific language impairments (SLIs) and dyslexia have severe deficits in processing rapidly presented or brief sensory information, both within the auditory and visual domains. This hypothesis has been supported through evidence that language-impaired individuals have excess auditory backward masking. This paper presents an analysis of masking results from several studies in terms of a model of temporal resolution. Results from this modeling suggest that the masking results can be better explained by an ``auditory efficiency'' hypothesis. If impaired or immature listeners have a normal temporal window, but require a higher signal-to-noise level (poor processing efficiency), this hypothesis predicts the observed small deficits in the simultaneous masking task, and the much larger deficits in backward and forward masking tasks amongst those listeners. The difference in performance on these masking tasks is predictable from the compressive nonlinearity of the basilar membrane. The model also correctly predicts that backward masking (i) is more prone to training effects, (ii) has greater inter- and intrasubject variability, and (iii) increases less with masker level than do other masking tasks. These findings provide a new perspective on the mechanisms underlying communication disorders and auditory masking.

  10. Auditory hedonic phenotypes in dementia: A behavioural and neuroanatomical analysis.

    Science.gov (United States)

    Fletcher, Phillip D; Downey, Laura E; Golden, Hannah L; Clark, Camilla N; Slattery, Catherine F; Paterson, Ross W; Schott, Jonathan M; Rohrer, Jonathan D; Rossor, Martin N; Warren, Jason D

    2015-06-01

    Patients with dementia may exhibit abnormally altered liking for environmental sounds and music but such altered auditory hedonic responses have not been studied systematically. Here we addressed this issue in a cohort of 73 patients representing major canonical dementia syndromes (behavioural variant frontotemporal dementia (bvFTD), semantic dementia (SD), progressive nonfluent aphasia (PNFA) amnestic Alzheimer's disease (AD)) using a semi-structured caregiver behavioural questionnaire and voxel-based morphometry (VBM) of patients' brain MR images. Behavioural responses signalling abnormal aversion to environmental sounds, aversion to music or heightened pleasure in music ('musicophilia') occurred in around half of the cohort but showed clear syndromic and genetic segregation, occurring in most patients with bvFTD but infrequently in PNFA and more commonly in association with MAPT than C9orf72 mutations. Aversion to sounds was the exclusive auditory phenotype in AD whereas more complex phenotypes including musicophilia were common in bvFTD and SD. Auditory hedonic alterations correlated with grey matter loss in a common, distributed, right-lateralised network including antero-mesial temporal lobe, insula, anterior cingulate and nucleus accumbens. Our findings suggest that abnormalities of auditory hedonic processing are a significant issue in common dementias. Sounds may constitute a novel probe of brain mechanisms for emotional salience coding that are targeted by neurodegenerative disease. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Establishing the Response of Low Frequency Auditory Filters

    Science.gov (United States)

    Rafaelof, Menachem; Christian, Andrew; Shepherd, Kevin; Rizzi, Stephen; Stephenson, James

    2017-01-01

    The response of auditory filters is central to frequency selectivity of sound by the human auditory system. This is true especially for realistic complex sounds that are often encountered in many applications such as modeling the audibility of sound, voice recognition, noise cancelation, and the development of advanced hearing aid devices. The purpose of this study was to establish the response of low frequency (below 100Hz) auditory filters. Two experiments were designed and executed; the first was to measure subject's hearing threshold for pure tones (at 25, 31.5, 40, 50, 63 and 80 Hz), and the second was to measure the Psychophysical Tuning Curves (PTCs) at two signal frequencies (Fs= 40 and 63Hz). Experiment 1 involved 36 subjects while experiment 2 used 20 subjects selected from experiment 1. Both experiments were based on a 3-down 1-up 3AFC adaptive staircase test procedure using either a variable level narrow-band noise masker or a tone. A summary of the results includes masked threshold data in form of PTCs, the response of auditory filters, their distribution, and comparison with similar recently published data.

  12. Intracavity interferometry using synchronously pumped OPO

    Science.gov (United States)

    Zavadilová, Alena; Vyhlídal, David; Kubeček, Václav; Šulc, Jan; Navrátil, Petr

    2016-12-01

    The concept of system for intracavity interferometry based on the beat note detection in subharmonic synchronously intracavity pumped optical parametrical oscillator (OPO) is presented. The system consisted of SESAM-modelocked, picosecond, diode pumped Nd:YVO4 laser, operating at wavelength 1.06 μm and tunable linear intracavity pumped OPO based on MgO:PPLN crystal, widely tunable in 1.5 μm able to deliver two independent trains of picosecond pulses. The optical length of the OPO cavity was set to be exactly twice the pumping cavity length. In this configuration the OPO produces signal pulses with the same repetition frequency as the pump laser but the signal consists of two completely independent pulse trains. For purpose of pump probe measurements the setup signal with half repetition rate and scalable amplitude was derived from the OPO signal using RF signal divider, electropotical modulator and fiber amplifier. The impact of one pump beam on the sample is detected by one probing OPO train, the other OPO train is used as a reference. The beat note measured using the intracavity interferometer is proportional to phase modulation caused by the pump beam. The bandwidth of observed beat-note was less than 1 Hz (FWHM), it corresponds to a phase shift measurement error of less than 1.5 × 10-7 rad without any active stabilization. Such compact low-cost system could be used for ultra-sensitive phase-difference measurements (e.g. nonlinear refractive index measurement) for wide range of material especially in spectral range important for telecom applications.

  13. Learning-induced synchronization and plasticity of a developing neural network.

    Science.gov (United States)

    Chao, T C; Chen, C M

    2005-12-01

    Learning-induced synchronization of a neural network at various developing stages is studied by computer simulations using a pulse-coupled neural network model in which the neuronal activity is simulated by a one-dimensional map. Two types of Hebbian plasticity rules are investigated and their differences are compared. For both models, our simulations show a logarithmic increase in the synchronous firing frequency of the network with the culturing time of the neural network. This result is consistent with recent experimental observations. To investigate how to control the synchronization behavior of a neural network after learning, we compare the occurrence of synchronization for four networks with different designed patterns under the influence of an external signal. The effect of such a signal on the network activity highly depends on the number of connections between neurons. We discuss the synaptic plasticity and enhancement effects for a random network after learning at various developing stages.

  14. Generalized projective synchronization of chaotic systems with unknown dead-zone input: observer-based approach.

    Science.gov (United States)

    Hung, Yung-Ching; Hwang, Chi-Chuan; Liao, Teh-Lu; Yan, Jun-Juh

    2006-09-01

    In this paper we investigate the synchronization problem of drive-response chaotic systems with a scalar coupling signal. By using the scalar transmitted signal from the drive chaotic system, an observer-based response chaotic system with dead-zone nonlinear input is designed. An output feedback control technique is derived to achieve generalized projective synchronization between the drive system and the response system. Furthermore, an adaptive control law is established that guarantees generalized projective synchronization without the knowledge of system nonlinearity, and/or system parameters as well as that of parameters in dead-zone input nonlinearity. Two illustrative examples are given to demonstrate the effectiveness of the proposed synchronization scheme.

  15. Synchronization of dynamic response measurements for the purpose of structural health monitoring

    International Nuclear Information System (INIS)

    Maes, K.; Reynders, E.; De Roeck, G.; Lombaert, G.; Rezayat, A.

    2016-01-01

    This paper presents a technique for offline time synchronization of data acquisition systems for linear structures with proportional damping. The technique can be applied when direct synchronization of data acquisition systems is impossible or not sufficiently accurate. The synchronization is based on the acquired dynamic response of the structure only, and does not require the acquisition of a shared sensor signal or a trigger signal. The time delay is identified from the spurious phase shift of the mode shape components that are obtained from system identification. A demonstration for a laboratory experiment on a cantilever steel beam shows that the proposed methodology can be used for accurate time synchronization, resulting in a significant improvement of the accuracy of the identified mode shapes. (paper)

  16. Synchronization of coupled chaotic dynamics on networks

    Indian Academy of Sciences (India)

    We review some recent work on the synchronization of coupled dynamical systems on a variety of networks. When nodes show synchronized behaviour, two ... [5], congregations of synchronously flashing fireflies [6], and cricket that chirp in unison [7]. Coupled oscillators were first studied by Winfree [8] and Kuramoto [9].

  17. Two novel synchronization criterions for a unified chaotic system

    International Nuclear Information System (INIS)

    Tao Chaohai; Xiong Hongxia; Hu Feng

    2006-01-01

    Two novel synchronization criterions are proposed in this paper. It includes drive-response synchronization and adaptive synchronization schemes. Moreover, these synchronization criterions can be applied to a large class of chaotic systems and are very useful for secure communication

  18. Auditory Scene Analysis and sonified visual images. Does consonance negatively impact on object formation when using complex sonified stimuli?

    Directory of Open Access Journals (Sweden)

    David J Brown

    2015-10-01

    Full Text Available A critical task for the brain is the sensory representation and identification of perceptual objects in the world. When the visual sense is impaired, hearing and touch must take primary roles and in recent times compensatory techniques have been developed that employ the tactile or auditory system as a substitute for the visual system. Visual-to-auditory sonifications provide a complex, feature-based auditory representation that must be decoded and integrated into an object-based representation by the listener. However, we don’t yet know what role the auditory system plays in the object integration stage and whether the principles of auditory scene analysis apply. Here we used coarse sonified images in a two-tone discrimination task to test whether auditory feature-based representations of visual objects would be confounded when their features conflicted with the principles of auditory consonance. We found that listeners (N = 36 performed worse in an object recognition task when the auditory feature-based representation was harmonically consonant. We also found that this conflict was not negated with the provision of congruent audio-visual information. The findings suggest that early auditory processes of harmonic grouping dominate the object formation process and that the complexity of the signal, and additional sensory information have limited effect on this.

  19. High Precision Clock Bias Prediction Model in Clock Synchronization System

    Directory of Open Access Journals (Sweden)

    Zan Liu

    2016-01-01

    Full Text Available Time synchronization is a fundamental requirement for many services provided by a distributed system. Clock calibration through the time signal is the usual way to realize the synchronization among the clocks used in the distributed system. The interference to time signal transmission or equipment failures may bring about failure to synchronize the time. To solve this problem, a clock bias prediction module is paralleled in the clock calibration system. And for improving the precision of clock bias prediction, the first-order grey model with one variable (GM(1,1 model is proposed. In the traditional GM(1,1 model, the combination of parameters determined by least squares criterion is not optimal; therefore, the particle swarm optimization (PSO is used to optimize GM(1,1 model. At the same time, in order to avoid PSO getting stuck at local optimization and improve its efficiency, the mechanisms that double subgroups and nonlinear decreasing inertia weight are proposed. In order to test the precision of the improved model, we design clock calibration experiments, where time signal is transferred via radio and wired channel, respectively. The improved model is built on the basis of clock bias acquired in the experiments. The results show that the improved model is superior to other models both in precision and in stability. The precision of improved model increased by 66.4%~76.7%.

  20. A Theoretical Framework for Soft-Information-Based Synchronization in Iterative (Turbo Receivers

    Directory of Open Access Journals (Sweden)

    Lottici Vincenzo

    2005-01-01

    Full Text Available This contribution considers turbo synchronization, that is to say, the use of soft data information to estimate parameters like carrier phase, frequency, or timing offsets of a modulated signal within an iterative data demodulator. In turbo synchronization, the receiver exploits the soft decisions computed at each turbo decoding iteration to provide a reliable estimate of some signal parameters. The aim of our paper is to show that such "turbo-estimation" approach can be regarded as a special case of the expectation-maximization (EM algorithm. This leads to a general theoretical framework for turbo synchronization that allows to derive parameter estimation procedures for carrier phase and frequency offset, as well as for timing offset and signal amplitude. The proposed mathematical framework is illustrated by simulation results reported for the particular case of carrier phase and frequency offsets estimation of a turbo-coded 16-QAM signal.