يعرض 1 - 4 نتائج من 4 نتيجة بحث عن '"Motor Imagery"', وقت الاستعلام: 0.86s تنقيح النتائج
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    المصدر: EEG Signal Processing: Feature extraction, selection and classification methods ISBN: 9781785613708

    الوصف: The presented analysis scenario shows how source reconstruction can be embedded in the EEG classification system and highlights its benefits for brain-computer interfaces (BCI) performance. Results of the analysis, trained classifiers, and selected feature indices can be directly used in BCI feedback training sessions. Linear inverse operators, such as WMNE, and sparse regions-of-interest are computationally simple enough to be applied in real-time settings.

  2. 2

    المؤلفون: A. P. Vinod, Kavitha P. Thomas

    المصدر: Signal Processing and Machine Learning for Brain-Machine Interfaces ISBN: 9781785613982

    الوصف: Brain-computer interface (BCI) is relatively a new approach to communication between man and machine, which translates brain activity into commands for communication and control. As BCI is capable of detecting human intentions, it is a promising communication tool for paralyzed patients for communicating with external world. Many of the current BCI systems employ electroencephalogram (EEG) which is the most widely used noninvasive brain activity recording technique. EEG signal carries potential features to identify and decode human intentions and mental tasks. Recently, many researchers have started exploiting the possibilities of BCI in entertainment and cognitive skill enhancement. BCI-based games have been identified as a unique entertainment mechanism nowadays, “controlling a 2-D, 3-D or virtual computer game solely by player's brain waves.” BCI games work based on a neurofeedback paradigm which allows an individual to self-regulate his brain signal in response to the real-time visual or auditory feedback of his brain waves/features. This neurofeedback in a gaming environment motivates and trains the players to control his brain features toward the desired stage (self-regulation). This chapter explores the state-of-the-art BCI technology in neurofeedback games, employing EEG signal. It also provides a survey of the existing EEG-based neurofeedback games and evaluates their success rates, challenging factors and influence on players. In neurofeedback games, a number of features extracted from EEG accompanied with sustained attention, selective attention, visuospatial attention, motor imagery, eye movements, etc. have been employed as distinct control signals. We will briefly review and compare various signal processing methodologies and machine-learning techniques employed in those studies to extract and decode the brain features. Besides the structure and algorithms used in neurofeedback games, the therapeutic effects of neurofeedback training and its capabilities for the enhancement of cognitive skills will also be briefly discussed in this chapter. Neurofeedback training helps to rewire brain's underlying neural circuits and to improve brain functions. Therefore, it is considered as an effective tool for boosting cognitive skills of both healthy and the disabled. Specifically, neurofeedback has been considered as an efficient treatment modality for individuals with attention-deficit hyperactive disorder (ADHD). ADHD is characterized by three behavioral symptoms: inattention, hyperactivity and impulsivity. Along with the conventional intervention strategies such as medication, behavioral treatments, etc., neurofeedback in BCI games has also been emerging as a promising modality for treating the attention deficit. We will also discuss portable and economical EEG recording devices currently employed in BCI-based brain training modules/games. Finally, the chapter will be concluded with a brief overview of the neurofeedback developments in the context of BCI-based games until now, their potential impact on the healthy as well as on people with neurological disorders, challenges in transferring the successful protocols from laboratories into the market and hurdles in real-time BCI system design and development.

  3. 3

    المؤلفون: Xinyang Li, Huijuan Yang, Cuntai Guan

    المصدر: Signal Processing and Machine Learning for Brain-Machine Interfaces ISBN: 9781785613982

    الوصف: Different mental states result in different synchronizations or desynchronizations between multiple brain regions, and subsequently, electroencephalogram (EEG) connectivity analysis gains increasing attention in brain computer interfaces (BCIs). Conventional connectivity analysis is usually conducted at the scalp-level and in an unsupervised manner. However, due to the volume conduction effect, EEG data suffer from low signal-to-noise ratio and poor spatial resolution. Thus, it is hard to effectively identify the task-related connectivity pattern at the scalp-level using unsupervised method. There exist extensive discriminative spatial filtering methods for different BCI paradigms. However, in conventional spatial filter optimization methods, signal correlations or connectivities are not taken into consideration in the objective functions. To address the issue, in this work, we propose a discriminative connectivity pattern-learning method. In the proposed framework, EEG correlations are used as the features, with which Fisher's ratio objective function is adopted to optimize spatial filters. The proposed method is evaluated with a binary motor imagery EEG dataset. Experimental results show that more connectivity information are maintained with the proposed method, and classification accuracies yielded by the proposed method are comparable to conventional discriminative spatial filtering method.

  4. 4

    المصدر: Scopus-Elsevier

    الوصف: Motor imagery on EEG signals are widely used in brain computer interface (BCI) system with many interesting applications. However, it is not easy to interpret motor imagery EEG signal due to non-stationary and noisy features of the signal. In this paper, we investigate three different techniques of energy calculation as a part of energy extraction methods including L2-norm, leverage score, and absolute Z-score. This BCI framework use CSP as motor imagery signal feature extraction method and extreme learning machine (ELM) to classify the features of motor imagery signal. In general, the investigated framework has proved that the energy extraction methods can improve the performance of CSP. Also, an effective EEG channel selection provides better performance in terms of classification accuracy. In general, the proposed energy extraction methods can offer up to 21% performance improvement in accuracy and 86% reduction number of channels as compared to the original CSP.