Chen Siyuan, Epps Julien, Chen Fang
Annu Int Conf IEEE Eng Med Biol Soc. 2013;2013:3202-5. doi: 10.1109/EMBC.2013.6610222.
Using the task-evoked pupillary response (TEPR) to index cognitive load can contribute significantly to the assessment of memory function and cognitive skills in patients. However, the measurement of pupillary response is currently limited to a well-controlled lab environment due to light reflex and also relies heavily on expensive video-based eye trackers. Furthermore, commercial eye trackers are usually dedicated to gaze direction measurement, and their calibration procedure and computing resource are largely redundant for pupil-based cognitive load measurement (PCLM). In this study, we investigate the validity of cognitive load measurement with (i) pupil light reflex in a less controlled luminance background; (ii) a low-cost infrared (IR) webcam for the TEPR in a controlled luminance background. ANOVA results show that with an appropriate baseline selection and subtraction, the light reflex is significantly reduced, suggesting the possibility of less constrained practical applications of PCLM. Compared with the TEPR from a commercial remote eye tracker, a low-cost IR webcam achieved a similar TEPR pattern and no significant difference was found between the two devices in terms of cognitive load measurement across five induced load levels.
使用任务诱发瞳孔反应（TEPR）来索引认知负荷，对于评估患者的记忆功能和认知技能有显著帮助。然而，由于光反射，目前瞳孔反应的测量仅限于控制良好的实验室环境，并且还严重依赖昂贵的基于视频的眼动仪。此外，商业眼动仪通常专注于注视方向测量，其校准程序和计算资源对于基于瞳孔的认知负荷测量（PCLM）在很大程度上是冗余的。在本研究中，我们调查了在（i）较不受控制的亮度背景下使用瞳孔光反射进行认知负荷测量的有效性；（ii）在受控亮度背景下使用低成本红外（IR）网络摄像头进行TEPR测量的有效性。方差分析结果表明，通过适当的基线选择和减法，光反射显著降低，这表明PCLM在实际应用中受较少限制的可能性。与商业远程眼动仪的TEPR相比，低成本IR网络摄像头获得了相似的TEPR模式，并且在五个诱发负荷水平的认知负荷测量方面，两种设备之间未发现显著差异。
