Dahal Nabaraj, Nandagopal D Nanda, Cocks Bernadine, Vijayalakshmi Ramasamy, Dasari Naga, Gaertner Paul
Cognitive Neuro-Engineering Laboratory, Division of IT, Engineering and Environment, University of South Australia, Adelaide, Australia.
J Neural Eng. 2014 Jun;11(3):036012. doi: 10.1088/1741-2560/11/3/036012. Epub 2014 May 8.
The objective of our current study was to look for the EEG correlates that can reveal the engaged state of the brain while undertaking cognitive tasks. Specifically, we aimed to identify EEG features that could detect audio distraction during simulated driving.
Time varying autoregressive (TVAR) analysis using Kalman smoother was carried out on short time epochs of EEG data collected from participants as they undertook two simulated driving tasks. TVAR coefficients were then used to construct all pole model enabling the identification of EEG features that could differentiate normal driving from audio distracted driving.
Pole analysis of the TVAR model led to the visualization of event related synchronization/desynchronization (ERS/ERD) patterns in the form of pole displacements in pole plots of the temporal EEG channels in the z plane enabling the differentiation of the two driving conditions. ERS in the EEG data has been demonstrated during audio distraction as an associated phenomenon.
Visualizing the ERD/ERS phenomenon in terms of pole displacement is a novel approach. Although ERS/ERD has previously been demonstrated as reliable when applied to motor related tasks, it is believed to be the first time that it has been applied to investigate human cognitive phenomena such as attention and distraction. Results confirmed that distracted/non-distracted driving states can be identified using this approach supporting its applicability to cognition research.
我们当前研究的目的是寻找能揭示大脑在进行认知任务时所处状态的脑电图(EEG)相关指标。具体而言,我们旨在识别能够在模拟驾驶过程中检测到音频干扰的EEG特征。
对参与者在进行两项模拟驾驶任务时收集的EEG数据的短时间段进行使用卡尔曼平滑器的时变自回归(TVAR)分析。然后使用TVAR系数构建全极点模型,以识别能够区分正常驾驶和音频干扰驾驶的EEG特征。
TVAR模型的极点分析导致以z平面中颞叶EEG通道的极点图中的极点位移形式可视化事件相关同步/去同步(ERS/ERD)模式,从而能够区分两种驾驶状态。EEG数据中的ERS已在音频干扰期间作为一种相关现象得到证实。
从极点位移的角度可视化ERD/ERS现象是一种新颖的方法。尽管ERS/ERD先前已被证明在应用于运动相关任务时是可靠的,但据信这是它首次被应用于研究诸如注意力和干扰等人类认知现象。结果证实,使用这种方法可以识别分心/未分心的驾驶状态,支持其在认知研究中的适用性。