Healy Graham, Smeaton Alan F
CLARITY, Centre for Sensor Web Technologies, School of Computing, Dublin City University, Glasnevin, Dublin 9, Ireland.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:4203-6. doi: 10.1109/IEMBS.2011.6091043.
Typically BCI (Brain Computer Interfaces) are found in rehabilitative or restorative applications, often allowing users a medium of communication that is otherwise unavailable through conventional means. Recently, however, there is growing interest in using BCI to assist users in searching for images. A class of neural signals often leveraged in common BCI paradigms are ERPs (Event Related Potentials), which are present in the EEG (Electroencephalograph) signals from users in response to various sensory events. One such ERP is the P300, and is typically elicited in an oddball experiment where a subject's attention is orientated towards a deviant stimulus among a stream of presented images. It has been shown that these types of neural responses can be used to drive an image search or labeling task, where we can rank images by examining the presence of such ERP signals in response to the display of images. To date, systems like these have been demonstrated when presenting sequences of images containing targets at up to 10 Hz, however, the target images in these tasks do not necessitate any kind of eye movement for their detection because the targets in the images are quite salient. In this paper we analyse the presence of discriminating EEG signals when they are offset to the time of eye fixations in a visual search task where detection of target images does require eye fixations.
通常，脑机接口（Brain Computer Interfaces，BCI）用于康复或恢复性应用，常常为用户提供一种通过传统方式无法实现的交流媒介。然而，最近人们对使用BCI协助用户搜索图像的兴趣与日俱增。在常见的BCI范式中经常利用的一类神经信号是事件相关电位（Event Related Potentials，ERPs），它们存在于用户的脑电图（Electroencephalograph，EEG）信号中，作为对各种感官事件的响应。其中一种ERP是P300，通常在一个oddball实验中诱发，在该实验中，受试者的注意力被导向一系列呈现图像中的一个异常刺激。已经表明，这些类型的神经反应可用于驱动图像搜索或标注任务，在这个任务中，我们可以通过检查响应图像显示时此类ERP信号的存在来对图像进行排序。迄今为止，当以高达10Hz的频率呈现包含目标的图像序列时，这样的系统已得到验证，然而，在这些任务中的目标图像检测并不需要任何类型的眼动，因为图像中的目标非常显著。在本文中，我们分析了在视觉搜索任务中，当脑电图信号偏移到眼注视时刻时鉴别性脑电图信号的存在情况，在该任务中，目标图像的检测确实需要眼注视。
