Patients with amyotrophic lateral sclerosis ( ALS ) often have difficulty in expressing their intentions through language and behavior, which prevents them from communicating properly with the outside world and seriously affects their quality of life. The brain-computer interface (BCI) has received much attention as an aid for ALS patients to communicate with the outside world, but the heavy device causes inconvenience to patients in the application process. To improve the portability of the BCI system, this paper proposed a wearable P300-speller brain-computer interface system based on the augmented reality (MR-BCI). This system used Hololens2 augmented reality device to present the paradigm, an OpenBCI device to capture EEG signals, and Jetson Nano embedded computer to process the data. Meanwhile, to optimize the system's performance for character recognition, this paper proposed a convolutional neural network classification method with low computational complexity applied to the embedded system for real-time classification. The results showed that compared with the P300-speller brain-computer interface system based on the computer screen (CS-BCI), MR-BCI induced an increase in the amplitude of the P300 component, an increase in accuracy of 1.7% and 1.4% in offline and online experiments, respectively, and an increase in the information transfer rate of 0.7 bit/min. The MR-BCI proposed in this paper achieves a wearable BCI system based on guaranteed system performance. It has a positive effect on the realization of the clinical application of BCI.
Humans ; Amyotrophic Lateral Sclerosis ; Brain-Computer Interfaces ; Quality of Life ; Event-Related Potentials, P300 ; Wearable Electronic Devices

Individual differences of P300 potentials lead to that a large amount of training data must be collected to construct pattern recognition models in P300-based brain-computer interface system, which may cause subjects' fatigue and degrade the system performance. TrAdaBoost is a method that transfers the knowledge from source area to target area, which improves learning effect in the target area. Our research purposed a TrAdaBoost-based linear discriminant analysis and a TrAdaBoost-based support vector machine to recognize the P300 potentials across multiple subjects. This method first trains two kinds of classifiers separately by using the data deriving from a small amount of data from same subject and a large amount of data from different subjects. Then it combines all the classifiers with different weights. Compared with traditional training methods that use only a small amount of data from same subject or mixed different subjects' data to directly train, our algorithm improved the accuracies by 19.56% and 22.25% respectively, and improved the information transfer rate of 14.69 bits/min and 15.76 bits/min respectively. The results indicate that the TrAdaBoost-based method has the potential to enhance the generalization ability of brain-computer interface on the individual differences.
Algorithms ; Brain-Computer Interfaces ; Discriminant Analysis ; Electroencephalography ; Event-Related Potentials, P300 ; Humans ; Support Vector Machine

BACKGROUND: Nasal polyposis is a chronic disease presenting with nasal obstruction as the most frequent complaint. It has been documented that nasal polyposis results in deterioration of quality of life and disturbances of sleep. However, remarkable consequences of nasal polyposis such as psychological and cognitive outcomes are relatively poorly studied. OBJECTIVE: The aim of the present study was to evaluate whether there is an impairment of concentration and attention in nasal polyposis patients due to hypoxia caused by nasal obstruction. METHODS: This cross-sectional, case-control study was carried out on 30 male patients with nasal polyps and 30 healthy subjects serving as controls. Participant ages were 41.6 ± 10.2 years in the nasal polyps group and 41.3 ± 6.2 in the control group. All participants underwent systemic, neurological, and otorhinolaryngological examinations together with routine hematological and biochemical tests. Patients with nasal polyposis had bilateral complete obstruction of nasal cavity. P300 component of electroencephalography-derived event related potentials were used to monitor concentration and attention. Nasal polyposis and control groups were compared in terms of amplitude and latency of P300. RESULTS: There were significant differences between control and nasal polyposis groups in terms of latency of P300 (p < 0.001). Nasal polyposis patient latencies in P300 were longer than controls (345.8 ± 16.6 msec, 309.3 ± 16.6 msec, respectively). However, there were no significant differences between control and nasal polyposis groups in terms of amplitude of P300 (p > 0.05). CONCLUSION: Results of the current study indicate that hypoxia due to complete nasal obstruction may result in impairment of attention and concentration in nasal polyposis patients. Assessment of patients with P300 latency subcomponent can be a useful diagnostic tool to detect cognitive and psychological consequences.
Anoxia ; Case-Control Studies ; Chronic Disease ; Cognition Disorders ; Event-Related Potentials, P300 ; Evoked Potentials ; Healthy Volunteers ; Humans ; Male ; Nasal Cavity ; Nasal Obstruction ; Nasal Polyps ; Quality of Life

We investigated event-related potentials (ERPs) to estimate the accuracy of eyewitness memories. Participants watched videos of vehicles being driven dangerously, from an anti-impaired driving initiative. The four-letter license plates of the vehicles were the target stimuli. Random numbers were presented while participants attempted to identify the license plate letters, and electroencephalograms were recorded. There was a significant difference in activity 300-500 milliseconds after stimulus onset, between target stimuli and random numbers. This finding contributes to establishing an eyewitness recognition model where different ERP components may reflect more explicit memory that is dissociable from recollection.
Electroencephalography ; Event-Related Potentials, P300 ; Evoked Potentials* ; Licensure ; Memory

This study seeks to explore the early signs of cognitive impairment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). According to polysomnography, twenty patients diagnosed with OSAHS and twenty normal controls underwent event-related potential (ERP) examination including mismatch negativity (MMN) and P300. Compared with normal controls, OSAHS patients showed significantly prolonged latency of MMN and P300 at Cz. After controlling age and body mass index (BMI), MMN latency positively correlated with apnea hypopnea index (AHI), oxygen reduction index, stage N1 sleep and arousal index, while MMN latency negatively correlated with stage N3 sleep and mean blood oxygen saturation; and P300 latency positively related to AHI and oxygen reduction index; no relationships were found among MMN latency, MMN amplitude, P300 latency and P300 amplitude. These results suggest that the brain function of automatic processing and controlled processing aere impaired in OSAHS patients, and these dysfunction are correlated with nocturnal repeatedly hypoxemia and sleep structure disturbance.
Case-Control Studies ; Cognition Disorders ; complications ; physiopathology ; Event-Related Potentials, P300 ; Humans ; Hypoxia ; physiopathology ; Oximetry ; Polysomnography ; Sleep Apnea, Obstructive ; complications ; physiopathology ; Sleep Stages

Using electroencephalogram (EEG) signal to control external devices has always been the research focus in the field of brain-computer interface (BCI). This is especially significant for those disabilities who have lost capacity of movements. In this paper, the P300-based BCI and the microcontroller-based wireless radio frequency (RF) technology are utilized to design a smart home control system, which can be used to control household appliances, lighting system, and security devices directly. Experiment results showed that the system was simple, reliable and easy to be populirised.
Brain ; physiology ; Brain-Computer Interfaces ; Electroencephalography ; Event-Related Potentials, P300 ; Humans

Feature extraction is a very crucial step in P300-based brain-computer interface (BCI) and independent component analysis (ICA) is a suitable P300 feature extraction method. But at present the convergence performance of the general ICA iteration methods are not very satisfactory. In this paper, a method based on quantum particle swarm optimizer (QPSO) algorithm and ICA technique is put forward for P300 extraction. In this method, quantum computing is used to impel ICA iteration to globally converge faster. It achieved the purpose of extracting P300 rapidly and efficiently. The method was tested on two public datasets of BCI Competition II and III, and a simple linear classifier was employed to classify the extracted P300 features. The recognition accuracy reached 94.4% with 15 times averaged. The results showed that the proposed method could extract P300 rapidly and the extraction effect did not reduce. It provides an experimental basis for further study of real-time BCI system.
Algorithms ; Brain-Computer Interfaces ; Electroencephalography ; Event-Related Potentials, P300 ; Humans ; Principal Component Analysis ; Signal Processing, Computer-Assisted

In the traditional P300 brain-computer interface (BCI) system, the electroencephalogram (EEG) signals can only provide limited information with a low signal-to-noise ratio. A BCI paradigm under visual stimulus was proposed in our study aiming to effectively activate the related brain areas and response signal while dealing with specific cognitive task (mental arithmetic task), so as to enhance the EEG signals. The result was compared with the traditional P300 counting task paradigm. Then the collected EEG data were preprocessed including extracting signal features with coherent averaging method, and analyzing the influences of different experimental paradigms on main components of event related potential (ERP). In the improved paradigm experiments the average increasing rate of P300 amplitude was 6. 83MV (73. 94%). The brain activity from 400ms was more active and lasted longer. Besides, unlike traditional counting task, mental arithmetic task appeared to have apparent activation at 650ms. The results showed that the improved paradigm could activate the related brain areas better and enhance the characteristics of signal. This provides a new system paradigm for BCI.
Brain-Computer Interfaces ; Electroencephalography ; Event-Related Potentials, P300 ; physiology ; Humans ; Mathematical Concepts ; Mental Processes ; physiology ; Task Performance and Analysis

Using human electroencephalogram (EEG) to control external devices in order to achieve a variety of functions has been focus of the field of brain-computer interface (BCI) research. P300 is experiments which stimulate the eye to produce EEG by using letters flashing, and then identify the corresponding letters. In this paper, some improvements based on the P300 experiments were made??. Firstly, the matrix of flashing letters were modified into words which represent a certain sense. Secondly, the BCI2000 procedures were added with the corresponding source code. Thirdly, the smart car systems were designed using the radiofrequency signal. Finally it was realized that the evoked potentials were used to control the state of the smart car.
Adult ; Automobiles ; Brain ; physiology ; Brain-Computer Interfaces ; Electroencephalography ; instrumentation ; methods ; Event-Related Potentials, P300 ; Evoked Potentials, Visual ; Female ; Humans ; Male ; Man-Machine Systems ; Task Performance and Analysis

OBJECTIVEQuantitative EEG and event-related potential P300 were used to evaluate impairment of cerebral function in patient with partial epilepsy.

METHODSW value was calculated (power of EEG δ and θ rhythm divided by power of α and β rhythm ) for the extent of focal cortical dysfunction. The W values in left partial epilepsy group, right partial epilepsy group and control group during interictal period compared. The latency, amplitude and reaction time of P300 potential change were observed in each groups.

RESULTSThe W values in F(8), T(4) and T(6) regions in patients with left partial epilepsy (P <0.05). The W values in T(3). O(1) regions of patients with left partial epilepsy were higher than those in patients with right partial epilepsy (P < 0.05). Furthermore, the W value in T(6) regions of patients with a disease course longer than 5y was significantly higher than that of patients with a disease course 1-5 y or less than 1y; the W value in O(2) regions of patients with a disease course longer than 5y was significantly higher than that of patients with a disease course between 1-5y (P < 0.05). In patients with right or left partial epilepsy, the total abnormal rate of P300 was 54. 76%, the latency, amplitude and reaction team were significantly different to the control group. The abnormal rate of P300 in left and right partial epilepsy groups were 77. 78% and 37.50%, respectively, and the former is significantly higher than the latter. The amplitudes of P300 in C(z) and P(z) of left partial epilepsy were significantly lower than those of right partial epilepsy and control group (P < 0.05). The latency and reaction time of P300 in C(z) and P(z) of all partial epilepsy were significantly longer than those of control group (P < 0.05), however, no difference was found between left and right partial epilepsy.

CONCLUSIONIn partial epilepsy the cortical dysfunction occurs ipsilaterally to the epileptogenic zone, and extent of cortical dysfunction is positively correlated with duration of disease course. Cerebral dysfunction in left partial epilepsy is more severe than that in right partial epilepsy.

Adult ; Electroencephalography ; Epilepsies, Partial ; physiopathology ; Event-Related Potentials, P300 ; physiology ; Female ; Humans ; Male ; Middle Aged ; Young Adult