Norepinephrine and acetylcholine regulate brain activity during changes in arousal and attention that are also reflected in fluctuations of the pupil. New research suggests that during goal-directed behavior, serotonin is also associated with pupil dilation.

中文翻译：

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眼睑测量：唤醒状态还是心灵状态？

去甲肾上腺素和乙酰胆碱调节觉醒和注意力变化期间的大脑活动，这也反映在瞳孔的波动中。新的研究表明，在目标导向的行为中，血清素也与瞳孔扩张有关。