What has a greater influence on time perception: the heart or emotions?

Time often seems to speed up or slow down depending on how we feel. Almost everyone has experienced situations in which a tense moment appeared to pass in an instant or, conversely, seemed to drag on. But does this experience depend mainly on what we see and feel, or can it also be influenced by signals coming from our own bodies, such as our heartbeat? To address this question, a team of researchers led by Manos Tsakiris investigated how emotions and cardiac activity affect the perception of duration.

Across two separate experiments involving 80 healthy adults, participants completed time-estimation tasks while their brain activity was recorded using electroencephalography (EEG). Stimuli were presented at specific moments of the cardiac cycle: either during systole, when the heart contracts and pumps blood through the body, or during diastole, when it relaxes between beats. In the first experiment, participants estimated the duration of simple visual patterns. In the second, they performed the same task with faces displaying either neutral or fearful expressions, allowing the researchers to compare the influence of cardiac signals and emotions on time perception.

The results showed that heartbeats alone had little impact on time perception. Contrary to what some previous studies had suggested, the researchers did not find a consistent effect across participants indicating that stimuli presented during a particular phase of the cardiac cycle were systematically perceived as shorter or longer. However, brain recordings revealed an interesting pattern: when stimuli were presented during systole, participants were more likely to underestimate their duration when the brain responded less strongly to those stimuli. In these cases, the interval appeared shorter than it actually was.

The strongest influence, however, came from emotions. Participants perceived fearful faces as remaining on the screen for a shorter time than neutral faces, even though they were presented for exactly the same duration. At the same time, fearful faces elicited stronger brain responses in regions involved in facial processing. The more emotionally arousing a face was perceived to be, the greater the tendency to underestimate its duration. This effect occurred regardless of the phase of the cardiac cycle during which the face was presented.

The authors conclude that the emotional content of a stimulus has a stronger influence on time perception than momentary fluctuations associated with the heartbeat. Nevertheless, the findings suggest that signals originating from the heart may subtly influence how the brain processes temporal information under certain circumstances. Understanding these interactions between emotion, bodily signals, and perception could contribute to a deeper understanding of the mechanisms through which the brain constructs the subjective experience of time.

This study forms part of project 126/22, In Search of Experienced Time: How Does the Heart-Brain Coupling Support the Perception of Time? supported by the Bial Foundation. The findings were published in the journal Neuropsychologia in the article Dissecting Emotional and Cardiac Contributions to Duration Perception: Evidence from Two EEG Experiments.

ABSTRACT

Time perception is inherently malleable, influenced by both emotional and bodily states. Past research suggests that transient heartbeat-linked interoceptive signals can modulate time perception, with some studies reporting that brief stimuli presented during cardiac systole are perceived as shorter than those during diastole. Here, we used electroencephalography (EEG) across two experiments to examine how such cardiac-phase effects are neurally instantiated, and how they interact with emotional content of the stimuli. In Experiment 1, participants judged the duration of brief neutral visual stimuli (Gabor patches) presented during systole or diastole. We did not observe a reliable group-level behavioural cardiac-phase effect. Despite that, EEG revealed systolic modulation of late visual activity. Crucially, exploratory analyses showed that more negative late cortical activity predicted temporal underestimation only during systole, not diastole. In Experiment 2, we extended this design to emotionally salient stimuli (neutral vs fearful faces). Fearful faces were perceived as shorter in duration and accompanied by enhanced N170-like negativity compared to neutral faces. But this effect was not modulated by cardiac phase, suggesting that emotional salience is a much more powerful driver of duration perception than subtle cardiac fluctuations. Yet, even for faces, enhanced EEG negativity predicted temporal contraction only during systole. Together, these findings reveal that while group-level behavioural cardiac-phase effects are variable, the systole-specific neural mechanism, whereby reduced cortical activity predicts temporal contraction, replicated across both experiments. This suggests that cardiac signals can shape duration perception through transient modulation of cortical processing.