Neuroscience Links Subjective Time Acceleration to Aging Brain Processing Changes

The common subjective experience of time accelerating with advancing age is increasingly being attributed to specific neurobiological phenomena rather than purely chronological measures. This temporal distortion, where years appear to compress, offers insights into the mechanics of human consciousness and the aging process. Scientists have focused on the underlying brain mechanisms that explain why the duration of days feels markedly shorter in adulthood compared to childhood.

Adrian Bejan, the J.A. Jones Distinguished Professor of Mechanical Engineering at Duke University, advanced a theory detailed in a 2019 publication in the European Review. Bejan posits that this sensation of temporal acceleration is tied to the maturation and subsequent degradation of the brain's neural pathways. As the brain develops, these information processing channels lengthen; with age, this increased path length introduces greater resistance, slowing electrical signal transmission. Bejan stated that the mind senses time changing when perceived images change, suggesting that younger brains process a greater quantity of novel mental images within a fixed objective time interval, which subjectively stretches perceived duration.

Conversely, older adults register fewer novel visual inputs during the same objective interval, leading to the perception of time moving faster. This rapid-fire processing in youth results in a greater cumulative store of visual impressions, making those periods feel more extended, analogous to a film strip with more frames. Complementary factors were explored by mathematical biologist Brian Yates of the University of Bath in 2016, focusing on biological metabolism and the impact of routine. Yates suggested that a natural decline in metabolic rate slows the body's internal biological clock, and a life dominated by routine minimizes the frequency of novel experiences recorded by the brain.

Empirical validation for the neural processing theory emerged from a 2025 study published in Communications Biology, which investigated 'neural states'—specific patterns of brain activity. This research demonstrated that these neural states become both longer in duration and less frequent as individuals age, particularly in sensory processing regions like the visual cortex. The study, involving 577 participants aged 18 to 88 within the Cambridge Center for Aging and Neuroscience (Cam-CAN) project, used fMRI scans while subjects viewed an eight-minute film clip. Findings indicated that younger brains transitioned between states more frequently, directly correlating with the subjective perception that time passes more quickly in older age due to fewer recorded 'cuts' in the mental experience of life.

This body of research explains a near-universal human experience through measurable neurobiological changes, linking time perception to the rate of new memory formation. Introducing novelty into daily life is suggested as a potential strategy to enrich memory encoding, which could retrospectively extend the perceived duration of time.