刺激类型对听觉稳态响应的影响

摘要

听觉稳态响应 (ASSR) 是一种由周期性声音信号诱发的稳态脑电响应, 能够用于听觉脑-机接口 (BCI) 的研究.为构建高速的基于ASSR的BCI系统, 需要寻求诱发较强ASSR的刺激类型.为此, 通过典型相关分析 (CCA), 比较14名健康受试者中短声 (click) 、正弦调幅音 (SAM) 和白噪声 (white noise) 3种刺激声所诱发的ASSR响应.实验结果表明, 3种刺激声均能诱发出稳定的ASSR, 而且ASSR响应最大的区域主要集中在额中央区.ASSR响应的强度依赖于刺激类型, click声诱发的ASSR最强, 白噪声次之, SAM声最弱.利用CCA分别对3种刺激声进行左右耳分类, 发现click声获得的信息传输率 (ITR) 最高, 达到6.69 bits/min;白噪声次之, 为1.65 bits/min;SAM声最弱, 为0.76 bits/min.这些结果提示, click声适合于构建高速的BCI系统.%Auditory steady state response (ASSR) is an electroencephalography (EEG) potential elicited by the periodic auditory stimuli, which can be used for building auditory brain-computer interface (BCI). In order to build efficient ASSR-based BCIs, it is necessary to seek a stimulation type to evoke stronger ASSR. In this work the canonical correlation analysis (CCA) was used to compare the ASSRs from 14 healthy subjects evoked by click, sinusoidal amplitude modulation (SAM), and white noise. Results indicated that the three stimulation types could evoke stable ASSR, and the strongest ASSR was mainly concentrated in frontal-central area. The strength of ASSR was depended on stimulation type. The strongest ASSR was obtained by the click stimuli. The second one and the weakest ASSR were corresponding to the white noise stimuli and SAM stimuli respectively. Using CCA to classify the left and right ears for the three stimulation types, we found out that the click stimuli induced the highest information transfer rate (ITR), which was 6.69 bits/min; the second one and the weakest ITR were corresponding to the white noise stimuli and SAM stimuli, which was 1.65 bits/min and 0.76 bits/min respectively. These results indicated that click stimuli was suitable for building high-speed BCI systems.