Sighs act as a reset button for breathing and arousal during monotonous tasks

A Psychophysiology study reported by PsyPost shows spontaneous sighs help reset breathing variability and are linked to pupil-dilation changes that reflect arousal, suggesting sighing supports physiological balance and alertness during long, dull tasks. In two experiments, sighs reduced later breathing variability after deep breaths, and increased pupil dilation aligned with arousal cycles; however, there was no immediate improvement in reaction times or self-reported focus. When participants breathed slowly on purpose, sighing declined, implying deliberate breathing can override the natural urge to sigh. Limitations include potential yawning confounding sigh detection and the tasks being relatively easy; more research is needed to see if sighing can tangibly boost performance in demanding environments.