Yijun Wang

Yijun Wang
Chinese Academy of Sciences | CAS · Institute of Semiconductors

PhD

About

200
Publications
82,252
Reads
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8,787
Citations
Citations since 2017
119 Research Items
6554 Citations
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
Additional affiliations
June 2015 - present
Chinese Academy of Sciences
Position
  • Research Associate
February 2008 - April 2015
University of California, San Diego
Position
  • Research Assistant
September 2001 - July 2007
Tsinghua University
Position
  • PhD Student

Publications

Publications (200)
Article
Full-text available
Objective.Existing steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) struggle to balance user experience and system performance. This study proposed an individualized space and phase modulation method to code imperceptible flickers at 60 Hz towards a user-friendly SSVEP-based BCI with high performance.Approach.The...
Article
Full-text available
Implantable intracortical microelectrodes can record a neuron’s rapidly changing action potentials (spikes). In vivo neural activity recording methods often have either high temporal or spatial resolution, but not both. There is an increasing need to record more neurons over a longer duration in vivo. However, there remain many challenges to overco...
Preprint
Full-text available
Flexible electrodes have demonstrated good biocompatibility compared to rigid electrodes in relieving encapsulation and long-term recording. The structural and functional properties of the brain in non-human primates are closer to those of humans than in rodents. However, the application of flexible electrodes on non-human primates has been rarely...
Preprint
Flexible neural microelectrodes demonstrate higher compliance and better biocompatibility than rigid electrodes. They have multiple microfilaments can be freely distributed across different brain regions. However, high-density fan-out of high-throughput flexible microelectrodes remains a challenge since monolithic integration between electrodes and...
Article
Poly(3,4-ethylenedioxythiophene) (PEDOT) is an organic material with good electrochemical activity and electrical conductivity, and it is usually electrochemically deposited on the neural probes to improve their interface properties. However, the workload for electrode modification using an electropolymerization method becomes greater with the incr...
Article
Full-text available
The practical functionality of a brain-computer interface (BCI) is critically affected by the number of stimuli, especially for steady-state visual evoked potential based BCI (SSVEP-BCI), which shows promise for the implementation of a multi-target system for real-world applications. Joint frequency-phase modulation (JFPM) is an effective and widel...
Article
Full-text available
The research on non-invasive BCI is nowadays hitting the bottleneck due to the humble quality of scalp EEG signals. Whereas invasive solutions that offer higher signal quality in contrast are suffocated in their spreading because of the potential surgical complication and health risks caused by electrode implantation. Therefore, it puts forward a n...
Article
Objective: Steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) have attracted increasing attention due to their high information transfer rate. To improve the performance of SSVEP detection, we propose a bidirectional Siamese correlation analysis (bi-SiamCA) model. Approach: In this model, an LSTM-based Siamese archi...
Article
Full-text available
The optimization of coding stimulus is a crucial factor in the study of steady-state visual evoked potential (SSVEP)-based brain-computer interface(BCI).This study proposed an encoding approach named Multi-Symbol Time Division Coding (MSTDC). This approach is based on a protocol of maximizing the distance between neural responses, which aims to enc...
Article
Full-text available
The visual attentional blink can be substantially reduced by delivering a task‐irrelevant sound synchronously with the second visual target (T2), and this effect is further modulated by the semantic congruency between the sound and T2. However, whether the cross‐modal benefit originates from audiovisual interactions or sound‐induced alertness remai...
Article
Full-text available
Global population aging poses an unprecedented challenge and calls for a rising effort in eldercare and healthcare. Steady-state visual evoked potential based brain-computer interface (SSVEP-BCI) boasts its high transfer rate and shows great promise in real-world applications to support aging. Public database is critically important for designing t...
Article
Full-text available
Flexible multichannel electrode arrays (fMEAs) with multiple filaments can be flexibly implanted in various patterns. It is necessary to develop a method for implanting the fMEA in different locations and at various depths based on the recording demands. This study proposed a strategy for reducing the microelectrode volume with integrated packaging...
Article
Full-text available
The steady-state visual evoked potential based brain–computer interface (SSVEP–BCI) can provide high-speed alternative and augmentative communication in real-world applications. For individuals using a long-term BCI, within-subject (i.e., cross-day and cross-electrode) transfer learning could improve the BCI performance and reduce the calibration b...
Article
Background In recent years, numerous studies on the brain-computer interface (BCI) have been published. However, the number of targets in most of the existing studies was not enough for many practical applications. New method: To achieve highly efficient communications, this study proposed a 120-target BCI system based on code-modulated visual evok...
Article
Full-text available
Electroencephalogram (EEG) electrodes are critical devices for brain-computer interface and neurofeedback. A pre-gelled (PreG) electrode was developed in this paper for EEG signal acquisition with a short installation time and good comfort. A hydrogel probe was placed in advance on the Ag/AgCl electrode before wearing the EEG headband instead of a...
Article
Full-text available
There are approximately 50 million people with epilepsy worldwide, even about 25% of whom cannot be effectively controlled by drugs or surgical treatment. A wireless closed-loop system for epilepsy detection and suppression is proposed in this study. The system is composed of an implantable optrode, wireless recording, wireless energy supply, and a...
Article
Full-text available
Brain-computer interface (BCI) based on steady-state visual evoked potential (SSVEP) has been widely studied due to the high information transfer rate (ITR), little user training, and wide subject applicability. However, there are also disadvantages such as visual discomfort and “BCI illiteracy.” To address these problems, this study proposes to us...
Article
Objective: The steady-state visual evoked potential based brain-computer interface (SSVEP-BCI) implemented in dry electrodes is a promising paradigm for alternative and augmentative communication in real-world applications. To improve its performance and reduce the calibration effort for dry-electrode systems, we utilize cross-device transfer lear...
Article
Full-text available
In the rapid serial visual presentation (RSVP) classification task, the data from the target and non-target classes are incredibly imbalanced. These class imbalance problems (CIPs) can hinder the classifier from achieving better performance, especially in deep learning. This paper proposed a novel data augmentation method called balanced Wasserstei...
Article
A brain-computer interface (BCI) system based on steady-state visual evoked potentials (SSVEP) was developed by four-class phase-coded stimuli. SSVEPs elicited by flickers at 60Hz, which is higher than the critical fusion frequency (CFF), were compared with those at 15Hz and 30Hz. SSVEP components in electroencephalogram (EEG) were detected using t...
Article
Full-text available
Objective: Visual attention is not homogeneous across the visual field, while how to mine the effective EEG characteristics that are sensitive to the inhomogeneous of visual attention and further explore applications such as the performance of brain-computer interface (BCI) are still distressing explorative scientists. Approach: Images were enco...
Article
Objective: Asynchronous brain-computer interfaces (BCIs) are more practical and natural compared to synchronous BCIs. A brain switch is a standard asynchronous BCI, which can automatically detect the specified change of the brain and discriminate between the control state and the idle state. The current brain switches still face challenges on rela...
Article
Objective. Steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI) has the characteristics of fast communication speed, high stability, and wide applicability, thus it has been widely studied. With the rapid development in paradigm, algorithm, and system design, SSVEP-BCI is gradually applied in clinical and real-life scen...
Article
Full-text available
Monolithic integrated μLED optrode has promising applications in optogenetics due to their ability to achieve more optical channels in a smaller footprint. The current used to drive the μLED will cause electromagnetic interference (EMI) noise to the recording electrodes at a very close distance. Utilizing a grounded metal shielding layer between th...
Article
Objective. There has become of increasing interest in transcranial alternating current stimulation (tACS) since its inception nearly a decade ago. tACS in modulating brain state is an active area of research and has been demonstrated effective in various neuropsychological and clinical domains. In the visual domain, much effort has been dedicated t...
Article
Full-text available
A brain-computer interface (BCI) provides a direct communication channel between a brain and an external device. Steady-state visual evoked potential based BCI (SSVEP-BCI) has received increasing attention due to its high information transfer rate, which is accomplished by individual calibration for frequency recognition. Task-related component ana...
Article
Full-text available
Objective.Low-frequency steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) systems with high performance are prone to cause visual discomfort and fatigue. High-frequency SSVEP-based BCI systems can alleviate the discomfort, but always obtain lower performance. This study optimized the spatial properties of a proposed...
Article
Objective: Electroencephalogram (EEG) is an objective reflection of the brain activities, which provides potential possibilities for brain state estimation based on EEG characteristics. However, how to mine the effective EEG characteristics is still a distressing problem in brain state monitoring. Approach: The phase-scrambled method was used to...
Article
Full-text available
The miniscope system is one of the calcium (Ca ²⁺ ) imaging tools with small size and lightweight and can realize the deep-brain Ca ²⁺ imaging not confined to the cerebral cortex. Combining Ca ²⁺ imaging and electrophysiology recording has been an efficient method for extracting high temporal-spatial resolution signals in the brain. In this study,...
Article
Full-text available
Elevated intraocular pressure (IOP) is the leading cause of glaucoma. As glaucoma is an irreversible neurological eye disease, it is urgent to realize timely and accurate IOP detection for diagnostic and therapeutic purposes. Here, a contact lens sensor for continuous IOP monitoring using self‐assembly graphene (SAG), is developed. The combination...
Article
Objective.Asynchronous brain-computer interfaces (BCIs) show significant advantages in many practical application scenarios. Compared with the rapid development of synchronous BCIs technology, the progress of asynchronous BCI research, in terms of containing multiple targets and training-free detection, is still relatively slow. In order to improve...
Article
Objective.Steady-state visual evoked potential (SSVEP) is an essential paradigm of electroencephalogram based brain-computer interface (BCI). Previous studies in the BCI research field mostly focused on enhancing classification accuracy and reducing stimuli duration. This study, however, concentrated on increasing the number of available targets in...
Article
Abstract- Objective: The speed of visual brain-computer interfaces (v-BCIs) has been greatly improved in recent years. However, the traditional v-BCI paradigms require users to directly gaze at the intensive flickering items, which would cause severe problems such as visual fatigue and excessive visual resource consumption in practical applications...
Article
A brain–computer interface (BCI) establishes a direct communication channel between a brain and an external device. With recent advances in neurotechnology and artificial intelligence (AI), the brain signals in BCI communication have been advanced from sensation and perception to higher-level cognition activities. While the field of BCI has grown r...
Article
Calcium (Ca²⁺) fluorescence is widely used to monitor the activity of neurons in vivo. We propose a method of detection the Ca²⁺ fluorescence intensity by integrating a μLED linear array and an optical fiber. Due to the different positions of each μLED, the range of excitation of each μLED cannot overlap that of another by controlling the luminous...
Article
Objective: Achieving high precision rapid serial visual presentation (RSVP) task often requires many electrode channels to obtain more information. However, the more channels may contain more redundant informations and also lead to its limited practical applications. Therefore, it is necessary to reduce the number of channels to enhance the classi...
Article
Full-text available
Conventional visual BCIs, in which control channels are tagged with stimulation patterns to elicit distinguishable brain patterns, has made impressive progress in terms of the information transfer rates (ITRs). However, less development has been seen with respect to user experience and complexity of the technical setup. The requirement to tag each...
Article
Full-text available
The present study recorded event-related potentials (ERPs) in a visual object-recognition task under the attentional blink paradigm to explore the temporal dynamics of the cross-modal boost on attentional blink and whether this auditory benefit would be modulated by semantic congruency between T2 and the simultaneous sound. Behaviorally, the presen...
Article
Electroencephalogram (EEG)-based biometrics have attracted increasing attention in recent years. A few studies have used visual evoked potentials (VEPs) in EEG biometrics due to their high signal-to-noise ratio (SNR) and good stability. However, a systematic comparison of different types of VEPs is still lacking. Therefore, this study proposes a sy...
Article
Full-text available
Brain-computer interfaces (BCIs) provide humans a new communication channel by encoding and decoding brain activities. Steady-state visual evoked potential (SSVEP)-based BCI stands out among many BCI paradigms because of its non-invasiveness, little user training, and high information transfer rate (ITR). However, the use of conductive gel and bulk...
Article
Full-text available
Intraocular pressure (IOP) is an essential indicator of the diagnosis and treatment of glaucoma. IOP has an apparent physiological rhythm, and it often reaches its peak value at night. To avoid missing the peak value at night and sample the entire rhythm cycle, the continuous monitoring of IOP is urgently needed. A wearable contact lens IOP sensor...
Article
Recent advances in robotics, neuroscience, and signal processing make it possible to operate a robot through electroencephalography (EEG)-based brain-computer interface (BCI). Although some successful attempts have been made in recent years, the practicality of the entire system still has much room for improvement. The present study designed and re...
Chapter
In this study, we developed a high-speed steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) system to address two long-standing challenges in BCIs: tedious user training and low applicability for target users. We designed a training-free method with low computational complexity called the spatio-temporal equalization...
Article
Full-text available
This paper reports on a benchmark dataset acquired with a brain–computer interface (BCI) system based on the rapid serial visual presentation (RSVP) paradigm. The dataset consists of 64-channel electroencephalogram (EEG) data from 64 healthy subjects (sub1,…, sub64) while they performed a target image detection task. For each subject, the data cont...
Article
Full-text available
Brain-computer interfaces (BCIs) based on rapid serial visual presentation (RSVP) have been widely used to categorize target and non-target images. However, it is still a challenge to detect single-trial event related potentials (ERPs) from electroencephalography (EEG) signals. Besides, the variability of EEG signal over time may cause difficulties...
Article
As the second leading cause of blindness in the world, glaucoma is mainly caused by persistent high intraocular pressure (IOP) that compresses the optic nerve and causes permanent damage. Noninvasive continuous monitoring of IOP is an essential method for the diagnosis and treatment of glaucoma. In this paper, we propose a new strain gauge material...
Article
Objective: The design of the stimulation paradigm plays an important role in steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) studies. Among various stimulation designs, the dual-frequency paradigm in which two frequencies are used to encode one target is of importance and interest. However, because the number of p...
Conference Paper
Full-text available
Visual brain-computer interface (BCI) systems have made tremendous process in recent years. It has been demonstrated to perform well in spelling words. However, different from spelling English words in one-dimension sequences, Chinese characters are often written in a two-dimensional structure. Previous studies had never investigated how to use BCI...
Conference Paper
Steady State Visual Evoked Potentials (SSVEPs) have been widely used in Brain-Computer Interfaces (BCIs). SSVEP-BCIs have advantages of high classification accuracy, high information transfer rate, and strong anti-interference ability. Traditional studies mostly used low/medium frequency SSVEPs as system control signals. However, visual flickers wi...
Conference Paper
Steady-State Visual Evoked Potentials (SSVEPs) have become one of the most used neural signals for brain- computer interfaces (BCIs) due to their stability and high signal- to-noise rate. However, the performance of SSVEP-based BCIs would degrade with a few training samples. This study was proposed to enhance the detection of SSVEP by combining the...
Conference Paper
The mapping of visual space onto human striate cortex allows the location of stimuli to affect the scalp distributions of electroencephalogram (EEG). To clarify the relationship between the characteristics of elicited high-frequency steady-state visual evoked potentials (SSVEPs) and the polar angle of stimulus, this study divided the annulus into e...
Conference Paper
Full-text available
Brain-computer interfaces (BCIs) allow for translating electroencephalogram (EEG) into control commands, e.g., to control a quadcopter. This study, we developed a practical BCI based on steady-state visually evoked potential (SSVEP) for continuous control of a quadcopter from the first-person perspective. Users watched with the video stream from a...
Conference Paper
In order to explore the effect of low frequency stimulation on pupil size and electroencephalogram (EEG), we presented subjects with 1-6Hz black-and-white-alternating flickering stimulus, and compared the differences of signal-to-noise ratio (SNR) and classification performance between pupil size and visual evoked potentials (VEPs). The results sho...
Article
Full-text available
The brain-computer interface (BCI) provides an alternative means to communicate and it has sparked growing interest in the past two decades. Specifically, for Steady-State Visual Evoked Potential (SSVEP) based BCI, marked improvement has been made in the frequency recognition method and data sharing. However, the number of pubic databases is still...
Article
Objective: Filter bank canonical correlation analysis (FBCCA) is a widely-used classification approach implemented in steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs). However, conventional detection algorithms for SSVEP recognition problems, including the FBCCA, were usually based on 'fixed window' strategy. Tha...
Preprint
There has become of increasing interest in transcranial alternating current stimulation (tACS) since its inception nearly a decade ago. tACS in modulating brain state is an active area of research and has been demonstrated effective in various neuropsychological and clinical domains. In the visual domain, much effort has been dedicated to brain rhy...
Article
Full-text available
Optogenetics transforms specific types of neurons through genetic engineering to achieve the cell membrane expression of photosensitive channel protein. When a specific wavelength of light irradiates the photosensitive channel protein, the cell is either excited or inhibited. Optogenetics provides a precise and fast method to control the activity o...
Article
Full-text available
Objective: Recently, electroencephalography (EEG)- based brain-computer interfaces (BCIs) have made tremendous progress in increasing communication speed. However, current BCI systems could only implement a small number of command codes, which hampers their applicability. Methods: This study developed a high-speed hybrid BCI system containing as...
Article
Digit symbol substitution test (DSST), which is a valid and sensitive tool to assess human cognitive dysfunction, has been widely used in clinical neuropsychology. Although several versions of DSST are currently available, most of the existing DSST versions rely on examinees' intact motor function. This limits their utility in severely motor-impair...
Article
Canonical correlation analysis (CCA) is an effective spatial filtering algorithm widely used in steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs). In existing CCA methods, training data are used for constructing templates of stimulus targets and the spatial filters are created between the template signals and a sin...
Article
This commentary presents a replication study to verify the effectiveness of a sum of squared correlations (SSCOR)-based steady-state visual evoked potentials (SSVEPs) decoding method proposed by Kumar et al.. We implemented the SSCOR-based method in accordance with their descriptions and estimated its classification accuracy using a benchmark SSVEP...
Article
Full-text available
The feasibility of a steady-state visual evoked potential (SSVEP) brain-computer interface (BCI) with a single-flicker stimulus for multiple-target decoding has been demonstrated in a number of recent studies. The single-flicker BCIs have mainly employed the direction information for encoding the targets, i.e., different targets are placed at diffe...
Article
Full-text available
Event-related potentials (ERPs) are one of the most popular control signals for brain-computer interfaces (BCIs). However, they are very weak and sensitive to the experimental settings including paradigms, stimulation parameters and even surrounding environments, resulting in a diversity of ERP patterns across different BCI experiments. It'