It is a truism that time seems to expand or contract depending on our circumstances: when we are afraid, seconds can stretch. If we spend a day alone, it can go slow. When we want to deliver something on time, the hours pass quickly.
A study published this month in the journal Psychophysiology by Cornell University psychologists found that, when observed at the microsecond level, some of these distortions could be generated by heartbeats, the duration of which varies from moment to moment.
Psychologists gave college students EKGs to accurately measure the duration of each beat, and then asked them to estimate the duration of short audio tones. Desired wishes that after a longer beat interval, subjects tended to perceive the tone to be longer; shorter intervals led participants to rate the pitch as shorter. After each tone, the subjects’ heartbeat intervals lengthened.
Saeedeh Sadeghi, a doctoral student at Cornell University and lead author of the study, noted that a lower heart rate seemed to help perception.
“When we need to perceive things from the outside world, the heartbeat is noise for the cerebral cortex,” he explains. “You can take in the world more—it’s easier to process things—when your heart is silent.”
Sadeghi says the study provides further evidence, after an era of brain-focused research, that “it’s not just one part of the brain or body that keeps track of time, but a whole network.” And he added: “The brain controls the heart and the heart, in turn, impacts the brain.”
Interest in the perception of time has boomed since the onset of the COVID-19 pandemic, when activities outside the home came to a screeching halt for many and people around the world were faced with stretches of time they could not differentiate
A study of time perception carried out during the first year of lockdown in the UK found that 80 per cent of participants reported perceiving distortions in time, in different directions. On average, people who were older and more isolated from social contexts reported that time slowed down; while younger, more active people reported it accelerating.
“Our experience of time is affected in ways that are, in general, similar to our well-being,” explained Ruth S. Ogden, Professor of Psychology at Liverpool John Moores University and author of the study during confinement: “People with depression experience a slowdown in time and that slowdown is perceived as a factor that worsens depression.
The new Cornell study addresses something different: how we perceive the passage of microseconds. Odgen said that understanding these mechanisms could help us manage trauma, in which instantaneous experiences are recorded as prolonged.
She said that when trying to assess the significance of an experience, “our brains just look back and say, ‘Well, how many memories did we make?’
He added: “When you have a very vivid memory, more vivid than you normally would of a 15-minute period of your life, your mind can make you believe it was very long.”
Hugo Critchley, a Professor of Psychiatry at Brighton and Sussex Medical School who has studied how heartbeats belong to how we remember words and fear responderHe stated that, until recently, research on time perception had focused on different areas of the brain.
Critchley, who was not involved in the Cornell heartbeat study, said: “I think it is now much more appreciated that cognitive functions are intimately linked, perhaps even grounded, in control of the body, whereas most of psychology studies until the 1990s ignored the body from the brain stem.
The professor opined that previous research has explored how physical arousal is connected to stress processing and emotional states such as anxiety and panic. The new study delves into that by digging into the heart’s role in a non-emotional function, time perception, which may be linked to larger distortions in thinking.
“Cognitive function cannot be examined in isolation,” he added. “Even by understanding how the brain develops and begins to represent internal mental states, people see the primacy of essential internal information that must be controlled to survive.”
Adam K. Anderson, a professor of psychology at Cornell and co-author of the new study, said that one reason the body might be intimately involved in the perception of time is that time is closely related to metabolic needs.
“Time is a resource,” Anderson concluded. “If the body were a battery or a gas tank, it would try to find out in real time: ‘How much energy do we have?’ We perceive that time runs slower or faster depending on how we have bodily energy”.
Ellen Barry covers mental health. She has served as Boston bureau chief for The Times, chief international correspondent in London, and bureau chief in Moscow and New Delhi. She was part of a team that won the Pulitzer for International Reporting in 2011. @EllenBarryNYT