认知需求被认为是调节两种常用的,但很少结合在一起,措施:瞳孔大小和神经α(8-12Hz)振荡功率。然而,目前尚不清楚这两种方法在复杂的视听任务条件下是否以类似的方式捕获认知需求。在这里,我们记录了瞳孔大小和神经α功率(使用脑电图),而两性的人类参与者同时执行视觉多目标跟踪任务和听觉间隙检测任务。两个任务的困难是相互独立的。随着认知需求的增加,参与者的表现在准确性和速度上都有所下降。瞳孔大小随着听觉和视觉任务难度的增加而增加。相比之下,α功率显示出不同的神经动力学:顶叶α功率随着视觉任务难度的增加而降低,但在听觉任务中难度越来越大。此外,独立于任务难度,在参与者内部,每个试验的瞳孔大小波动与α功率呈负相关.困难引起的瞳孔大小和α功率的变化,然而,不相关,这与他们不同的认知需求敏感性是一致的。总的来说,当前的研究表明,在复杂的视听任务条件下,认知需求和相关努力的神经生理指标的动力学是多方面的,并且可能取决于模态。显著性陈述瞳孔大小和振荡α功率与认知需求和努力有关,但是它们在复杂的视听任务条件下的相对敏感性尚不清楚,以及它们共享潜在机制的程度。使用视听双重任务范式,我们表明,瞳孔大小随着听觉和视觉认知需求的增加而增加。相比之下,振荡α功率的变化取决于各自的任务需求:顶叶α功率随视觉需求而降低,但不随听觉任务需求而降低。因此,瞳孔大小和α功率对认知需求表现出不同的敏感性,也许暗示了部分不同的潜在神经机制。
Cognitive demand is thought to modulate two often used, but rarely combined, measures: pupil size and neural α (8-12 Hz) oscillatory power. However, it is unclear whether these two measures capture cognitive demand in a similar way under complex audiovisual-task conditions. Here we recorded pupil size and neural α power (using electroencephalography), while human participants of both sexes concurrently performed a visual multiple object-tracking task and an auditory gap detection task. Difficulties of the two tasks were manipulated independent of each other. Participants\' performance decreased in accuracy and speed with increasing cognitive demand. Pupil size increased with increasing difficulty for both the auditory and the visual task. In contrast, α power showed diverging neural dynamics: parietal α power decreased with increasing difficulty in the visual task, but not with increasing difficulty in the auditory task. Furthermore, independent of task difficulty, within-participant trial-by-trial fluctuations in pupil size were negatively correlated with α power. Difficulty-induced changes in pupil size and α power, however, did not correlate, which is consistent with their different cognitive-demand sensitivities. Overall, the current study demonstrates that the dynamics of the neurophysiological indices of cognitive demand and associated effort are multifaceted and potentially modality-dependent under complex audiovisual-task conditions.SIGNIFICANCE STATEMENT Pupil size and oscillatory α power are associated with cognitive demand and effort, but their relative sensitivity under complex audiovisual-task conditions is unclear, as is the extent to which they share underlying mechanisms. Using an audiovisual dual-task paradigm, we show that pupil size increases with increasing cognitive demands for both audition and vision. In contrast, changes in oscillatory α power depend on the respective task demands: parietal α power decreases with visual demand but not with auditory task demand. Hence, pupil size and α power show different sensitivity to cognitive demands, perhaps suggesting partly different underlying neural mechanisms.