Section Computational Cognitive Neuroscience, Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Cognitive and Systems Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
Sci Rep. 2024 Nov 17;14(1):28380. doi: 10.1038/s41598-024-78791-8.
The arousal systems of the brainstem, specifically the locus coeruleus-noradrenaline system, respond "phasically" during decisions. These central arousal transients are accompanied by dilations of the pupil. Mechanistic attempts to understand the impact of phasic arousal on cognition would benefit from temporally precise experimental manipulations. Here, we evaluated a non-invasive candidate approach to manipulate arousal in humans: presenting task-irrelevant auditory stimuli at different latencies during the execution of a challenging task. Task-irrelevant auditory stimuli drive responses of brainstem nuclei involved in the control of pupil size, but it is unknown whether such sound-evoked responses mimic the central arousal transients evoked during cognitive computations. A large body of evidence has implicated central arousal transients in reducing bias during challenging perceptual decisions. We thus used challenging visual decisions as a testbed, combining them with task-irrelevant sounds of varying onset latency or duration. Across three experiments, the sounds consistently elicited well-controlled pupil responses that superimposed onto task-evoked responses. While we replicated a negative correlation between task-evoked pupil responses and bias, the task-irrelevant sounds had no behavioral effect. This dissociation suggests that cognitive task engagement and task-irrelevant sounds may recruit distinct neural systems contributing to the control of pupil size.
大脑脑干的觉醒系统，特别是蓝斑-去甲肾上腺素系统，在决策过程中会“相位性”地反应。这些中枢觉醒瞬变伴随着瞳孔的扩张。为了从时间上精确地理解相位性觉醒对认知的影响，机制性的尝试需要依赖于实验操控。在这里，我们评估了一种非侵入性的候选方法来操纵人类的觉醒：在执行具有挑战性的任务时，以不同的延迟呈现与任务无关的听觉刺激。与任务无关的听觉刺激会驱动控制瞳孔大小的脑干核的反应，但尚不清楚这种声音诱发的反应是否模拟了在认知计算过程中产生的中枢觉醒瞬变。大量证据表明，中枢觉醒瞬变有助于减少在具有挑战性的感知决策中的偏差。因此，我们使用具有挑战性的视觉决策作为测试平台，将它们与具有不同起始潜伏期或持续时间的与任务无关的声音结合起来。在三个实验中，声音一致地引起了很好控制的瞳孔反应，这些反应叠加在任务诱发的反应上。虽然我们复制了任务诱发的瞳孔反应与偏差之间的负相关，但与任务无关的声音没有行为影响。这种分离表明，认知任务的参与和与任务无关的声音可能会招募到不同的神经系统来控制瞳孔大小。
