Abstract:
In this study, we attempted to improve brain-computer interface (BCI) systems by means of auditory stream segregation in which alternately presented tones are perceived as sequences of various different tones (streams). A 3-class BCI using three tone sequences, which were perceived as three different tone streams, was investigated and evaluated. Each presented musical tone was generated by a software synthesizer. Eleven subjects took part in the experiment. Stimuli were presented to each user\'s right ear. Subjects were requested to attend to one of three streams and to count the number of target stimuli in the attended stream. In addition, 64-channel electroencephalogram (EEG) and two-channel electrooculogram (EOG) signals were recorded from participants with a sampling frequency of 1000 Hz. The measured EEG data were classified based on Riemannian geometry to detect the object of the subject\'s selective attention. P300 activity was elicited by the target stimuli in the segregated tone streams. In five out of eleven subjects, P300 activity was elicited only by the target stimuli included in the attended stream. In a 10-fold cross validation test, a classification accuracy over 80% for five subjects and over 75% for nine subjects was achieved. For subjects whose accuracy was lower than 75%, either the P300 was also elicited for nonattended streams or the amplitude of P300 was small. It was concluded that the number of selected BCI systems based on auditory stream segregation can be increased to three classes, and these classes can be detected by a single ear without the aid of any visual modality.
摘要:
在这项研究中,我们试图通过听觉流分离来改善脑机接口(BCI)系统,其中交替呈现的音调被感知为各种不同音调(流)的序列。使用三个音调序列的3类BCI,它们被认为是三种不同的音调流,进行了调查和评估。每个呈现的音乐音调由软件合成器生成。11名受试者参加了实验。刺激被呈现给每个用户的右耳。要求受试者参加三个流之一,并计算参加流中的目标刺激的数量。此外,以1000Hz的采样频率记录了参与者的64通道脑电图(EEG)和两通道眼电图(EOG)信号。根据黎曼几何对测量的EEG数据进行分类,以检测受试者的选择性注意的对象。P300活性是由分离的音调流中的目标刺激引起的。在11个科目中有5个,P300活动仅由参与流中包含的目标刺激引起。在10倍交叉验证测试中,5名受试者的分类准确率超过80%,9名受试者的分类准确率超过75%.对于准确率低于75%的受试者,对于无人值守的流也引起了P300,或者P300的幅度很小。结论是,基于听觉流隔离的选定BCI系统的数量可以增加到三类,这些类别可以在没有任何视觉模态的帮助下被单耳检测到。