Summary: Momentary perceptions of time can stretch or contract with each heartbeat and are not continuous, as previously thought.
Source: Cornell University
How long is the present? The answer, Cornell researchers suggest in a new study, depends on your heart.
They discovered that our momentary perception of time is not continuous but can stretch or shrink with each heartbeat.
Research shows that the heart is one of the brain’s important timekeepers and plays a vital role in our sense of passing time, an idea that has been contemplated since ancient times, said Adam K. Anderson, a professor in the Department of Psychology and at the College of Human Ecology (CHE).
“Time is a dimension of the universe and a fundamental basis for our experience of self,” Anderson said. “Our research shows that moment-to-moment experience of time is synchronized and changes with the duration of a heartbeat.”
Saeedeh Sadeghi, a doctoral student in the field of psychology, is the lead author of “Wrinkles in Subsecond Time Perception are Synchronized to the Heart,” published March 2 in the journal Psychophysiology. Anderson co-authored with Eve De Rosa, Mibs Martin Follett Professor in Human Ecology (CHE) and dean of faculty at Cornell, and Marc Wittmann, senior research scientist at the Institute for Frontier Areas of Psychology and Mental Health in Germany.
Time perception has typically been tested over longer ranges, when research has shown that thoughts and emotions can distort our sense of time, perhaps causing it to fly or crawl. Sadeghi and Anderson recently reported, for example, that crowding made a simulated train ride seem to pass more slowly.
Such findings, Anderson said, tend to reflect how we think about or estimate time, rather than our direct experience of it in the present moment.
To investigate that more direct experience, the researchers asked whether our perception of time is related to physiological rhythms, focusing on natural heart rate variability. The heart pacemaker “ticks” constantly on average, but each interval between beats is slightly longer or shorter than the previous one, like a second hand ticking at different intervals.
The team exploited this variability in a new experiment. Forty-five study participants, ages 18 to 21, with no history of heart problems, were monitored with electrocardiography, or ECG, measuring the heart’s electrical activity to millisecond resolution. The ECG was connected to a computer, which made it possible to activate short tones lasting 80-180 milliseconds from heartbeats. Study participants reported whether the tones were longer or shorter than the others.
The results revealed what the researchers called “time lines.” When the heartbeat preceding a tone was shorter, the tone was perceived as longer. When the previous heartbeat was longer, the duration of the sound seemed shorter.
“These observations systematically demonstrate that cardiac dynamics, even within a few heartbeats, are related to temporal decision making,” the authors wrote.
The study also showed that the brain influences the heart. After hearing the tones, the study participants focused their attention on the sounds. That “orientation response” changed their heart rate, affecting their experience of time.
“The heartbeat is a rhythm that our brain uses to give us a sense of time passing,” Anderson said, “and it’s not linear, it’s constantly contracting and expanding.”
Scholars said the connection between time perception and the heart suggests that our momentary perception of time is rooted in bioenergetics, helping the brain manage effort and resources based on changing bodily states, including heart rate. .
Research shows, Anderson said, that in sub-second intervals too brief for conscious thoughts or feelings, the heart regulates our experience of the present.
“Even at these moment-to-moment intervals, our sense of time is fluctuating,” he said. “A sheer influence of the heart, from beat to beat, helps create a sense of timing.”
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Author: James Dean
Source: Cornell University
Contact: James Dean-Cornell University
Image: Image is public domain
Original research: Access closed.
“Wrinkles in sub-second time perception are synchronized with the heart” by Saeedeh Sadeghi et al. Psychophysiology
Wrinkles in sub-second perception of time are synchronized with the heart
The role of the heart in the experience of time has long been theorized but empirical evidence is scarce. Here, we examined the interplay between fine-grained cardiac dynamics and the momentary experience of sub-second intervals.
Participants performed a temporal bisection task for short tones (80-188 ms) synchronized with the heart. We developed a cardiac drift-diffusion model (cDDM) that incorporated the dynamics of the concurrent heart rate into the temporal decision model.
The results revealed the existence of temporal wrinkles – dilation or contraction of short intervals – in synchrony with cardiac dynamics. A lower prestimulus heart rate was associated with an initial bias in coding the millisecond-level stimulus duration as longer, consistent with facilitation of sensory intake.
At the same time, a higher prestimulus heart rate aided in more consistent and quicker temporal judgments through more efficient evidence accumulation. Furthermore, higher post-stimulus cardiac deceleration rate, a bodily marker of attention, was associated with higher accumulation of sensory temporal evidence in the cDDM.
These results suggest a unique role of cardiac dynamics in the momentary experience of time. Our cDDM framework opens a new methodological avenue to investigate the role of the heart in time perception and perceptual judgment.