Pupil-linked arousal with very light exercise: pattern of pupil dilation during graded exercise

Abstract

Although it has been hypothesized that moderate to vigorous exercise immediately modulates cognition via ascending arousal system activation, such activation during very-light to light exercise has remained uncertain. Here, we aimed to uncover the exact exercise intensity necessary for ascending arousal system activation using pupillometry. The pupil diameter, psychological arousal, and ventilation during graded exercise of 26 young males were analyzed based on %$${\dot{V}}_{{\text{O}}_{\text{2peak}}}$$ V ˙ O 2peak . Pupils dilated with very-light exercise compared to rest, stabilized, and then drastically increased again with moderate exercise and above. Pupil dilation with very-light exercise was positively correlated with increases in psychological arousal. Thus, we have shown that there are two phases of pupil dilation during graded exercise: one with very-light exercise coinciding with psychological arousal response, and the other with moderate exercise or above similar to the ventilation increase pattern. This unique pupil dilation pattern provides physiological evidence of ascending arousal system activation with very-light exercise.

Light-exercise-induced dopaminergic and noradrenergic stimulation in the dorsal hippocampus: using a rat physiological exercise model

“…Classically, it is known that exercise can promote arousal, 35–37 which is thought to originate from the activation of the ascending arousal system (AAS). 38,39 This is supported by our recent studies showing that arousal promotion can occur by exercise even at very light-intensity accompanied by pupil dilation, 34,40–43 which reflects the activity of AAS. 44–48 The AAS sends out widespread projections in order to increase global brain activity, including the dorsal hippocampus, which largely overlaps the monoaminergic neuromodulatory system.…”

A randomized cross‐over trial investigating the neurocognitive effects of acute exercise on face recognition in children with autism spectrum disorder

“…In addition to the flexible modulation of attentional resources, a single aerobic exercise session also expands these resources by increasing arousal. This is indicated by a greater dilation of pupils during aerobic exercise with increasing intensity (Hayashi et al, 2010; Kuwamizu et al, 2022). Previous findings further indicated that pupil size remains increased during cognitive load, when the task is preceded by moderately‐intense aerobic exercise (Shigeta et al, 2021).…”

Cholinergic‐related pupil activity reflects level of emotionality during motor performance

“…The intensity of physical exercise in the absence of visual cues has been previously associated with an increased baseline pupil diameter (Hayashi et al, 2010;Zénon et al, 2014), which, when performed with moderate intensity, was comparable with when participants performed mental arithmetic tasks (Hayashi et al, 2010). Subsequent studies have corroborated these findings using measures of peak oxygen consumption ( _ V O 2 ) and minute ventilation ( _ V E ), further demonstrating that exercise-intensitydependent pupil dilation was exponentially correlated to these physiological measures (Kuwamizu et al, 2022). Other studies have tested the effects of single bouts of exercise on cognitive inhibitory control as measured by pupillometry following the physical activity, suggesting that task enhancement was, to some degree, independent of LC-related pupil activity (McGowan et al, 2019;Shigeta et al, 2021).…”