Psychobiological and Metabolic Correlates of Time Perception in Humans: An Exploratory Study.

Time perception-the subjective sense of how quickly or consistently time passes-shows striking variability across individuals, yet its physiological basis remains poorly understood. We hypothesized that internal clock speed and trial-to-trial variability in time perception would be linked to physiological and behavioral states. In a cohort of healthy adults (n = 59) and individuals carrying rare mitochondrial DNA mutations affecting mitochondrial energy transformation (n = 36), we explored the associations between time perception (time estimation and production) with measures of immune mitochondrial bioenergetics, blood catecholamines, working memory, and structural and functional neuroimaging. We found weak evidence suggesting that internal clock speed and time perception variability correlated with age and physiological metrics including resting energy expenditure, serum and urine norepinephrine levels, mood and fatigue, working memory performance, and neuroimaging measures of brain structure and function. Individuals with mitochondrial disorders and those with healthy mitochondria exhibited no main difference in time perception. However, they exhibited differential relations with physiological and neural variables, suggesting that mitochondria may moderate how specific processes influence time perception. These results provide a foundation for future studies to examine how cellular bioenergetics relate to time perception in humans.