Oregon Hearing Research Center, Oregon Health and Science University, Portland, United States.
Neuroscience Graduate Program, Oregon Health and Science University, Portland, United States.
Elife. 2021 Feb 11;10:e60153. doi: 10.7554/eLife.60153.
Both generalized arousal and engagement in a specific task influence sensory neural processing. To isolate effects of these state variables in the auditory system, we recorded single-unit activity from primary auditory cortex (A1) and inferior colliculus (IC) of ferrets during a tone detection task, while monitoring arousal via changes in pupil size. We used a generalized linear model to assess the influence of task engagement and pupil size on sound-evoked activity. In both areas, these two variables affected independent neural populations. Pupil size effects were more prominent in IC, while pupil and task engagement effects were equally likely in A1. Task engagement was correlated with larger pupil; thus, some apparent effects of task engagement should in fact be attributed to fluctuations in pupil size. These results indicate a hierarchy of auditory processing, where generalized arousal enhances activity in midbrain, and effects specific to task engagement become more prominent in cortex.
总的觉醒状态和参与特定任务都会影响感觉神经处理。为了在听觉系统中分离这些状态变量的影响，我们在雪貂进行音调检测任务时记录了初级听觉皮层（A1）和下丘（IC）的单个神经元活动，同时通过瞳孔大小的变化监测觉醒状态。我们使用广义线性模型评估任务参与度和瞳孔大小对声音诱发活动的影响。在这两个区域中，这两个变量影响了独立的神经元群体。瞳孔大小的影响在 IC 中更为明显，而在 A1 中，瞳孔和任务参与的影响同样可能。任务参与度与较大的瞳孔相关；因此，一些明显的任务参与度的影响实际上应该归因于瞳孔大小的波动。这些结果表明听觉处理存在一个层次结构，其中总的觉醒状态增强了中脑的活动，而特定于任务参与的影响在皮层中变得更为突出。
