Abstract:
Motivation plays a role when a listener needs to understand speech under acoustically demanding conditions. Previous work has demonstrated pupil-linked arousal being sensitive to both listening demands and motivational state during listening. It is less clear how motivational state affects the temporal evolution of the pupil size and its relation to subsequent behavior. We used an auditory gap detection task (N = 33) to study the joint impact of listening demand and motivational state on the pupil size response and examine its temporal evolution. Task difficulty and a listener\'s motivational state were orthogonally manipulated through changes in gap duration and monetary reward prospect. We show that participants\' performance decreased with task difficulty, but that reward prospect enhanced performance under hard listening conditions. Pupil size increased with both increased task difficulty and higher reward prospect, and this reward prospect effect was largest under difficult listening conditions. Moreover, pupil size time courses differed between detected and missed gaps, suggesting that the pupil response indicates upcoming behavior. Larger pre-gap pupil size was further associated with faster response times on a trial-by-trial within-participant level. Our results reiterate the utility of pupil size as an objective and temporally sensitive measure in audiology. However, such assessments of cognitive resource recruitment need to consider the individual\'s motivational state.
摘要:
当听众需要在声学要求苛刻的条件下理解语音时,动机起着作用。先前的工作表明,与瞳孔相关的唤醒对听力要求和听力时的动机状态都很敏感。动机状态如何影响瞳孔大小的时间演变及其与后续行为的关系尚不清楚。我们使用听觉间隙检测任务(N=33)来研究听力需求和动机状态对瞳孔大小反应的联合影响,并检查其时间演变。任务难度和听众的动机状态是通过间隙持续时间和金钱奖励前景的变化而正交操纵的。我们表明,参与者的表现随着任务难度而下降,但是这种奖励前景在认真倾听的条件下提高了表现。瞳孔大小随着任务难度和奖励前景的增加而增加,在困难的聆听条件下,这种奖励前景效应最大。此外,瞳孔大小的时间课程在检测到的和错过的间隙之间有所不同,表明瞳孔反应表明即将发生的行为。更大的间隙前瞳孔大小与更快的响应时间在逐个试验的参与者水平上进一步相关。我们的结果重申了瞳孔大小作为听力学中客观和时间敏感指标的实用性。然而,这种对认知资源招募的评估需要考虑个人的动机状态。重要性陈述文献没有定论,认为瞳孔大小可以代表听力任务需求和个人动机状态之间的相互作用。使用听觉间隙检测任务,我们操纵了倾听需求的程度和一个人的动机状态,并研究了瞳孔大小响应的时间演变及其与行为的关系。我们发现,瞳孔大小代表了需求和动机状态的相互作用。这些结果突出了在使用瞳孔大小作为临床测量时考虑一个人的动机状态的重要性。在评估动机状态对认知资源招募的影响时,瞳孔大小似乎是一个关键工具。