University of Toulouse, CNRS (UMR5263), 5 allées Antonio Machado, 31058 Toulouse Cedex 9, France.
University of Toulouse, CNRS (UMR5263), 5 allées Antonio Machado, 31058 Toulouse Cedex 9, France; ENAC École Nationale d'Aviation Civile, 7 Avenue Édouard Belin, 31055 Toulouse, France.
Int J Psychophysiol. 2018 Jan;123:111-120. doi: 10.1016/j.ijpsycho.2017.10.004. Epub 2017 Oct 7.
Cognitive workload is of central importance in the fields of human factors and ergonomics. A reliable measurement of cognitive workload could allow for improvements in human machine interface designs and increase safety in several domains. At present, numerous studies have used electroencephalography (EEG) to assess cognitive workload, reporting the rise in cognitive workload to be associated with increases in theta band power and decreases in alpha band power. However, results have been inconsistent with some failing to reach the required level of significance. We hypothesized that the lack of consistency could be related to individual differences in task performance and/or to the small sample sizes in most EEG studies. In the present study we used EEG to assess the increase in cognitive workload occurring in a multitasking environment while taking into account differences in performance. Twenty participants completed a task commonly used in airline pilot recruitment, which included an increasing number of concurrent sub-tasks to be processed from one to four. Subjective ratings, performances scores, pupil size and EEG signals were recorded. Results showed that increases in EEG alpha and theta band power reflected increases in the involvement of cognitive resources for the completion of one to three subtasks in a multitasking environment. These values reached a ceiling when performances dropped. Consistent differences in levels of alpha and theta band power were associated to levels of task performance: highest performance was related to lowest band power.
认知负荷在人因工程学和工效学领域中至关重要。可靠的认知负荷测量方法可以改进人机界面设计，并在多个领域提高安全性。目前，许多研究都使用脑电图（EEG）来评估认知负荷，报告称认知负荷的增加与 theta 波段功率的增加和 alpha 波段功率的降低有关。然而，结果并不一致，有些研究未能达到所需的显著性水平。我们假设这种不一致可能与任务表现的个体差异或大多数 EEG 研究中的小样本量有关。在本研究中，我们使用脑电图来评估在多任务环境中认知负荷的增加，同时考虑到表现的差异。二十名参与者完成了一项常用于航空公司飞行员招聘的任务，该任务包括从一个到四个同时处理的子任务。记录了主观评分、表现得分、瞳孔大小和脑电图信号。结果表明，在多任务环境中，完成一到三个子任务时，脑电图 alpha 和 theta 波段功率的增加反映了认知资源的增加。当表现下降时，这些值达到了上限。alpha 和 theta 波段功率的一致差异与任务表现水平相关：表现最高与波段功率最低相关。
