Compared to cardiac parameters and skin conductivities, the photoplethysmogram (PPG) recorded at fingertips and other parts near to peripheral nerve ends have been recently revealed to be yet another sensitive measure for cognitive load assessment. However, there is so far no research on measuring adolescents’ cognitive load using physiological signals. A comprehensive study on the effects of PPG morphometrics over a cohort covering both adolescent and adult students is also absent. In this study, we analyze the morphological features of PPG on cognitive load assessment and compare them between adolescent and adult students. Experiments on two-level arithmetic tasks show that the PPG morphometrics reached the same level of significance on the effect of task difficulty/period as heart rate, and different morphological behaviors were also shown between adolescent and adult students during the cognitive task effects, which may imply their physiological differences across age. Physiological signals recorded by wearable devices are also found to be effective in measuring cognitive load.

与心脏参数和皮肤电导率相比，在指尖和周围神经末梢附近其他部位记录的光电容积图 (PPG) 最近被发现是另一种认知负荷评估的敏感指标。然而，目前还没有关于利用生理信号测量青少年认知负荷的研究。对 PPG 形态测量学对涵盖青少年和成人学生的队列影响的综合研究也没有进行。在这项研究中，我们分析了 PPG 在认知负荷评估中的形态特征，并在青少年和成人学生之间进行了比较。两级算术任务的实验表明，PPG 形态计量学对任务难度/周期的影响达到与心率相同的显着水平，青少年和成年学生在认知任务效应期间也表现出不同的形态行为，这可能暗示他们在不同年龄段的生理差异。还发现可穿戴设备记录的生理信号可有效测量认知负荷。