scholarly journals Introducing Rhythmic Sinusoidal Amplitude-Modulated Auditory Stimuli with Multiple Message Frequency Coding for Fatigue Reduction in Normal Subjects: An EEG Study

2019 ◽  
Author(s):  
Elham Shamsi ◽  
Zahra Shirzhiyan ◽  
Ahmadreza Keihani ◽  
Morteza Farahi ◽  
Amin Mahnam ◽  
...  
Keyword(s):  
Signal Processing ◽  
Correlation Coefficient ◽  
Classification Accuracy ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Normal Subjects ◽  
Auditory Stimuli ◽  
Frequency Coding ◽  
Information Transfer Rate ◽  
Auditory Bci

AbstractMany of the brain-computer interface (BCI) systems depend on the user’s voluntary eye movements. However, voluntary eye movement is impaired in people with some neurological disorders. Since their auditory system is intact, auditory paradigms are getting more patronage from researchers. However, lack of appropriate signal-to-noise ratio in auditory BCI necessitates using long signal processing windows to achieve acceptable classification accuracy at the expense of losing information transfer rate. Because users eagerly listen to their interesting stimuli, the corresponding classification accuracy can be enhanced without lengthening of the signal processing windows. In this study, six sinusoidal amplitude-modulated auditory stimuli with multiple message frequency coding have been proposed to evaluate two hypotheses: 1) these novel stimuli provide high classification accuracies (greater than 70%), 2) the novel rhythmic stimuli set reduces the subjects’ fatigue compared to its simple counterpart. We recorded EEG from nineteen normal subjects (twelve female). Five-fold cross-validated naïve Bayes classifier classified EEG signals with respect to power spectral density at message frequencies, Pearson’s correlation coefficient between the responses and stimuli envelopes, canonical correlation coefficient between the responses and stimuli envelopes. Our results show that each stimuli set elicited highly discriminative responses according to all the features. Moreover, compared to the simple stimuli set, listening to the rhythmic stimuli set caused significantly lower subjects’ fatigue. Thus, it is worthwhile to test these novel stimuli in a BCI experiment to enhance the number of commands and reduce the subjects’ fatigue.Significance StatementAuditory BCI users eagerly listen to the stimuli they are interested in. Thus, response classification accuracy may be enhanced without the need for trial lengthening. Since humans enjoy listening to rhythmic sounds, this study was carried out for introducing novel rhythmic sinusoidal amplitude-modulated auditory stimuli with multiple message frequency coding. Our results show that each stimuli set evoked reliably discriminative responses according to all the features, and rhythmic stimuli set caused significantly lower fatigue in subjects. Thus, it is worthwhile to test these novel stimuli in a BCI study to increase the number of commands (by NN permutations of just N message frequencies) and reduce the subjects’ fatigue.

scholarly journals A low-cost auditory multi-class brain-computer interface based on pitch, spatial and timbre cues

2013 ◽  
Author(s):  
Zacharias Vamvakousis ◽  
Rafael Ramirez
Keyword(s):  
Healthy Subjects ◽  
Transfer Rate ◽  
Information Transfer ◽  
Low Cost ◽  
Auditory Stimuli ◽  
Stimulus Interval ◽  
Inter Stimulus Interval ◽  
Auditory P300 ◽  
Information Transfer Rate ◽  
Cord Injury

P300-based brain-computer interfaces (BCIs) are especially useful for people with illnesses, which prevent them from communicating in a normal way (e.g. brain or spinal cord injury). However, most of the existing P300-based BCI systems use visual stimulation which may not be suitable for patients with sight deterioration (e.g. patients suffering from amyotrophic lateral sclerosis). Moreover, P300-based BCI systems rely on expensive equipment, which greatly limits their use outside the clinical environment. Therefore, we propose a multi-class BCI system based solely on auditory stimuli, which makes use of low-cost EEG technology. We explored different combinations of timbre, pitch and spatial auditory stimuli (TimPiSp: timbre-pitch-spatial, TimSp: timbre-spatial, and Timb: timbre-only) and three inter-stimulus intervals (150ms, 175ms and 300ms), and evaluated our system by conducting an oddball task on 7 healthy subjects. This is the first study in which these 3 auditory cues are compared. After averaging several repetitions in the 175ms inter-stimulus interval, we obtained average selection accuracies of 97.14%, 91.43%, and 88.57% for modalities TimPiSp, TimSp, and Timb, respectively. Best subject’s accuracy was 100% in all modalities and inter-stimulus intervals. Average information transfer rate for the 150ms inter-stimulus interval in the TimPiSp modality was 14.85 bits/min. Best subject’s information transfer rate was 39.96 bits/min for 175ms Timbre condition. Based on the TimPiSp modality, an auditory P300 speller was implemented and evaluated by asking users to type a 12-characters-long phrase. Six out of 7 users completed the task. The average spelling speed was 0.56 chars/min and best subject’s performance was 0.84 chars/min. The obtained results show that the proposed auditory BCI is successful with healthy subjects and may constitute the basis for future implementations of more practical and affordable auditory P300-based BCI systems.

SSVEP Recognition by Using Higher Harmonics Based on Music

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Kun Chen ◽  
Fei Xu ◽  
Quan Liu ◽  
Haojie Liu ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Transfer Rate ◽  
Information Transfer ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Signal To Noise Ratio ◽  
Signal Classification ◽  
Recognition Time ◽  
Multiple Signal Classification ◽  
Computer Interfaces ◽  
Information Transfer Rate

Among different brain–computer interfaces (BCIs), the steady-state visual evoked potential (SSVEP)-based BCI has been widely used because of its higher signal to noise ratio (SNR) and greater information transfer rate (ITR). In this paper, a method based on multiple signal classification (MUSIC) was proposed for multidimensional SSVEP signal processing. Both fundamental and second harmonics of SSVEPs were employed for the final target recognition. The experimental results proved it has the advantage of reducing recognition time. Also, the relation between the duty-cycle of the stimulus signals and the amplitude of the second harmonics of SSVEPs was discussed via experiments. In order to verify the feasibility of proposed methods, a two-layer spelling system was designed. Different subjects including those who have never used BCIs before used the system fluently in an unshielded environment.

scholarly journals A low-cost auditory multi-class brain-computer interface based on pitch, spatial and timbre cues

2013 ◽  
Author(s):  
Zacharias Vamvakousis ◽  
Rafael Ramirez
Keyword(s):  
Healthy Subjects ◽  
Transfer Rate ◽  
Information Transfer ◽  
Low Cost ◽  
Auditory Stimuli ◽  
Stimulus Interval ◽  
Inter Stimulus Interval ◽  
Auditory P300 ◽  
Information Transfer Rate ◽  
Cord Injury

P300-based brain-computer interfaces (BCIs) are especially useful for people with illnesses, which prevent them from communicating in a normal way (e.g. brain or spinal cord injury). However, most of the existing P300-based BCI systems use visual stimulation which may not be suitable for patients with sight deterioration (e.g. patients suffering from amyotrophic lateral sclerosis). Moreover, P300-based BCI systems rely on expensive equipment, which greatly limits their use outside the clinical environment. Therefore, we propose a multi-class BCI system based solely on auditory stimuli, which makes use of low-cost EEG technology. We explored different combinations of timbre, pitch and spatial auditory stimuli (TimPiSp: timbre-pitch-spatial, TimSp: timbre-spatial, and Timb: timbre-only) and three inter-stimulus intervals (150ms, 175ms and 300ms), and evaluated our system by conducting an oddball task on 7 healthy subjects. This is the first study in which these 3 auditory cues are compared. After averaging several repetitions in the 175ms inter-stimulus interval, we obtained average selection accuracies of 97.14%, 91.43%, and 88.57% for modalities TimPiSp, TimSp, and Timb, respectively. Best subject’s accuracy was 100% in all modalities and inter-stimulus intervals. Average information transfer rate for the 150ms inter-stimulus interval in the TimPiSp modality was 14.85 bits/min. Best subject’s information transfer rate was 39.96 bits/min for 175ms Timbre condition. Based on the TimPiSp modality, an auditory P300 speller was implemented and evaluated by asking users to type a 12-characters-long phrase. Six out of 7 users completed the task. The average spelling speed was 0.56 chars/min and best subject’s performance was 0.84 chars/min. The obtained results show that the proposed auditory BCI is successful with healthy subjects and may constitute the basis for future implementations of more practical and affordable auditory P300-based BCI systems.

scholarly journals Способ компенсации интерференционного поля станционных радиопомех в коротковолновых широкополосных каналах радиосвязи

2020 ◽  
Author(s):  
I.M. Oroshchuk ◽  
M.V. Soloviev ◽  
A.N. Suchkov ◽  
A.A. Gavrilov
Keyword(s):  
Signal Processing ◽  
Spatial Correlation ◽  
Transfer Rate ◽  
Information Transfer ◽  
Narrow Band ◽  
Short Wave ◽  
Interference Field ◽  
Information Transfer Rate ◽  
Correlation Signal Processing ◽  
Correlation Properties

В работе представлены результаты экспериментальных исследований пространственно-корреляционных свойств узкополосных станционных помех коротковолнового диапазона. По результатам обработки экспериментальных данных получены обобщающие закономерности пространственно-корреляционных свойств интерференционного поля узкополосных станционных помех, определяющие возможность компенсации их влияния при обработке широкополосных сигналов в коротковолновых каналах радиосвязи, использующих цифровые антенные решетки с пространственно-корреляционной обработкой сигналов. С учетом возможностей компенсации интерференционного поля узкополосных станционных помех, исследована возможность повышения помехоустойчивости и скорости передачи информации в ионосферных каналах радиосвязи за счет передачи широкополосных сигналов с применением OFDM модуляции, более адаптируемой к условиям дисперсионных искажений и временного рассеяния сигналов, возникающих при распространении коротких волн. Результаты моделирования показали потенциальную возможность обеспечения повышенной скорости передачи информации в коротковолновых каналах с пространственно-корреляционной обработкой сигналов с заданной помехоустойчивостью при малых отношениях уровней сигнал/шум в точке приема, обеспечиваемой при меньших ограничениях выбора рабочей частоты, по сравнению с возможностями новых разработок скоростных коротковолновых модемов, в условиях ограниченности частотного ресурса коротковолнового диапазона из-за большой загруженности работой территориально-разнесенных станций.The experimental studies results of the spatial-correlation properties of narrow-band short-wave station interference are presents. Based on the results of processing the experimental data generalizing regularities of the interference field spatial-correlation properties of narrow-band station noise have been obtained. These regularities determine the possibility of compensating for their influence during processing broadband signals in radio channels using digital antenna arrays with spatial-correlation signal processing. Taking into account the possibilities of compensating for the interference field of narrow-band noise, the possibility of increasing the information transfer rate by transmitting wide-band signals using modulation with OFDM, which is more adaptable to the conditions of dispersion distortion and temporal dispersion of signals arising from the propagation of short waves in ionospheric communication channels, has been studied. The simulation results showed the potential for providing an increased information transfer rate in short-wave radio channels with spatial-correlation signal processing with a given noise immunity at low signal-to-noise levels at the receiving point, provided with less restrictions on the choice of operating frequency, compared with the capabilities of new developments of high-speed HF modems, in conditions of limited frequency resource of the HF band due to the heavy workload of geographically dispersed stations.

Multi-Channel SSVEP Pattern Recognition Based on MUSIC

2014 ◽  
Vol 539 ◽  
pp. 84-88 ◽  
Author(s):  
Kun Chen ◽  
Quan Liu ◽  
Qing Song Ai
Keyword(s):  
Information Transfer ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Recognition Accuracy ◽  
Signal To Noise Ratio ◽  
Frequency Resolution ◽  
Disabled People ◽  
Multiple Signal Classification ◽  
Computer Interfaces ◽  
Information Transfer Rate

Brain computer interfaces (BCIs) have become a research hotspot in recent years because of great potentials to help disabled people communicate with the outside world. Among different paradigms, steady state visual evoked potential (SSVEP)-based BCIs are commonly implemented in real applications, because they provide higher signal to noise ratio (SNR) and greater information transfer rate (ITR) than other BCI techniques. Various algorithms have been employed for SSVEP signal processing, like fast Fourier transform (FFT), wavelet analysis and canonical correlation analysis (CCA). In this paper, a new method based on multiple signal classification (MUSIC) was proposed for SSVEP feature extraction. The experimental results proved that it could provide higher frequency resolution and the recognition accuracy was excellent via adjusting some parameters.

scholarly journals Neurofeedback training of control network improves SSVEP-based BCI performance in children

2021 ◽  
Author(s):  
Sun Jingnan ◽  
Jing He ◽  
Xiaorong Gao
Keyword(s):  
Information Transfer ◽  
Parietal Lobe ◽  
Signal To Noise Ratio ◽  
Modulation Method ◽  
Control Group ◽  
Control Network ◽  
Neurofeedback Training ◽  
Electromagnetic Stimulation ◽  
Information Transfer Rate ◽  
Underlying Mechanisms

Abstract Background: In the past 20 years, neural engineering has made unprecedented progress in the interpretation of brain information (e.g., brain-computer interfaces) and neuromodulation (e.g., electromagnetic stimulation and neurofeedback). However, the study of improving the performance of the brain-computer interface (BCI) using the neuromodulation method rarely exists. The present study designs a neurofeedback training method to improve the performance of steady-state visual evoked potential (SSVEP) BCI and further explores its underlying mechanisms. Methods: As the parietal lobe is the sole hub of information transmission, up-regulating alpha-band power of the parietal lobe by neurofeedback training was presented in this study as a new neural modulation method to improve SSVEP-based BCI in this study. Results: After this neurofeedback training (NFT), the signal-to-noise ratio (SNR), accuracy, and information transfer rate (ITR) of SSVEP-based BCI were increased by 5.8%, 4.7%, and 15.6% respectively. However, no improvement has been observed in the control group in which the subjects do not participate in NFT. Evidence from the network analysis and attention test further indicate that NFT improves attention via developing the control ability of the parietal lobe and then enhances the above SSVEP indicators.Conclusion: Up-regulating parietal alpha-amplitude using neurofeedback training significantly improves the SSVEP-baesd BCI performance through modulating the control network. The study validates an effective neuromodulation method, and possibly also contributes to explaining the function of the parietal lobe in the control network.

INTERCONNECTION OF VIVALDI ANTENNAS IN THE MIMO ANTENNA ARRAY

2021 ◽  
pp. 108-111
Author(s):  
С.М. Фёдоров ◽  
Е.А. Ищенко ◽  
И.А. Зеленин ◽  
Е.В. Папина ◽  
Е.Д. Меньшикова ◽  
...  
Keyword(s):  
Antenna Array ◽  
Correlation Coefficient ◽  
Communication Systems ◽  
Information Transfer ◽  
Diversity Gain ◽  
Stable Operation ◽  
Mimo Antenna ◽  
Information Transfer Rate ◽  
Vivaldi Antennas ◽  
Envelope Correlation

Рассматривается MIMO антенная решетка, сформированная из двух антенн Вивальди, которые должны обеспечить работу в частотном диапазоне, выделенном для сетей пятого поколения - 24,25-24,65 ГГц. Для определения основных параметров антенны применялось моделирование, на основе которого были установлены основные характеристики MIMO антенной решетки: коэффициент корреляции огибающей, коэффициент усиления при разнесенном режиме, эффективность сложения. По результатам было определено, что при расстоянии между антеннами в 6,13 мм достигаются максимально возможные характеристики MIMO антенной решетки, а для стабильного функционирования достаточным является расстояние в 2,45 мм. В статье приводятся размеры исследуемой антенны, графики обратных потерь (S - параметров), диаграммы направленности, коэффициентов корреляции огибающих, коэффициента усиления при разнесенном режиме, эффективности сложения при различных расстояниях между антенными элементами. Обеспечение стабильности работы MIMO антенной решетки является важной задачей, так как все современные системы связи используют эту технологию для реализации многоканальной передачи, а следовательно, для повышения скорости передачи информации. Для определения геометрических характеристик и выполнения моделирования применялось специализированное программное обеспечение The article discusses a MIMO antenna array formed of two Vivaldi antennas, which should provide operation in the frequency range allocated for fifth generation networks - 24.25-24.65 GHz. To determine the main parameters of the antenna, we applied modeling, on the basis of which we determined the main characteristics of the MIMO antenna array: the envelope correlation coefficient, the diversity gain, the multiplexing efficiency. According to the results, we determined that with a distance between antennas of 6.13 mm, the maximum possible characteristics of a MIMO antenna array are achieved, and a distance of 2.45 mm is sufficient for stable operation. The article gives the dimensions of the antenna under study, graphs of return loss (S11 - parameters), radiation patterns, envelope correlation coefficient, diversity gain, multiplexing efficiency at different distances between the antenna elements. Ensuring the stability of the MIMO antenna array is an important task since all modern communication systems use this technology to implement multichannel transmission, and, consequently, to increase the information transfer rate. We used specialized software to determine geometric characteristics and perform modeling

INFORMATION TRANSFER RATE OF NEURONS: STOCHASTIC RESONANCE OF SHANNON'S INFORMATION CHANNEL CAPACITY

2001 ◽  
Vol 01 (01) ◽  
pp. L13-L19 ◽  
Author(s):  
LASZLO B. KISH ◽  
GREGORY P. HARMER ◽  
DEREK ABBOTT
Keyword(s):  
Stochastic Resonance ◽  
Channel Capacity ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Resonance Region ◽  
Information Channel ◽  
Effective Measure ◽  
Input Noise ◽  
Information Transfer Rate ◽  
Versus Input

The information channel capacity of neurons is calculated in the stochastic resonance region using Shannon's formula. This quantity is an effective measure of the quality of signal transfer, unlike the information theoretic calculations previously used, which only characterize the entropy of the output and not the rate of information transfer. The Shannon channel capacity shows a well pronounced maximum versus input noise intensity. The location of the maximum is at a higher input noise level than has been observed for classical measures, such as signal-to-noise ratio.

Soliton orthogonal frequency division multiplexing with phase–frequency coding on the base of inverse scattering transform

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Stepan A. Bogdanov ◽  
Leonid L. Frumin
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Information Transfer ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Scattering Problems ◽  
Noticeable Increase ◽  
Frequency Coding ◽  
Information Transfer Rate ◽  
Direct Scattering ◽  
Scattering Transform

Abstract We propose a method for increasing the speed and spectral efficiency of information transmission over soliton communication lines, based on algorithms for solving inverse and direct scattering problems, in the frame of a modern soliton orthogonal frequency division multiplexing (SOFDM) approach. The proposed method uses a simultaneous phase and frequency coding. This phase–frequency coding method retains all the technological advantages of the SOFDM method, and due to the additional frequency coding, a noticeable increase in the information transfer rate over the soliton optical lines is expected. Numerical modeling confirmed the proposed method for telecommunication applications’ prospects.

BRAIN SIGNATURES PERSPECTIVE FOR HIGH-SECURITY AUTHENTICATION

2020 ◽  
Vol 32 (04) ◽  
pp. 2050025
Author(s):  
Nikhil Rathi ◽  
Rajesh Singla ◽  
Sheela Tiwari
Keyword(s):  
Classification Accuracy ◽  
Information Transfer ◽  
Rejection Rate ◽  
Internet Banking ◽  
P300 Speller ◽  
Security Authentication ◽  
Information Transfer Rate ◽  
Shoulder Surfing ◽  
Authentication System ◽  
High Level

In the recent past, the web (internet) has emerged as the most interactive authentication system for all of us (i.e. Internet banking passwords, system or building access, and e-payment platforms, etc.) and as a result, traditional authentication systems (like passwords or token-based) are never again more secure i.e. they are vulnerable to attacks. As a result, the security of individual information and safe access to a system winds up prime necessities. Therefore, the EEG-based authentication system has recently become a reasonable key for high-level security. This study centers upon P300 evoked potential-based authentication system designing. In this paper, a new visual stimulus paradigm (i.e. [Formula: see text] P300 speller) using pictures of different objects as stimuli for a person authentication system is designed instead of the conventional character-based paradigm (i.e. [Formula: see text] speller) for increasing the classification accuracy and Information Transfer Rate (ITR). The trial begins by exhibiting a collection of pictures of various objects on four corners of the PC screen comprising of random object pictures (non-target) alongside password pictures (target) that trigger P300 reactions. The P300 reaction’s rightness then checks the identity of the subject concerning the focused pictures (Target). The proposed investigation model achieves higher classification accuracy of 96.78%, along with 0.03075 False Rejection Rate (FRR), 0.03297 False Acceptation Rate (FAR), and ITR of [Formula: see text]. This study has shown that P300-based authentication system has an advantage over conventional methods (Password, Token, etc.) as EEG-based systems cannot be mimicked or forged (like Shoulder surfing in case of password) and can still be used for disabled users with a brain in good running condition. The classification results revealed that the performance of the QDA classifier outperformed other classifiers based on accuracy and ITR.

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