Dissecting emotional and cardiac contributions to duration perception: Evidence from two EEG experiments

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysics

Background:

• Time perception is dynamic, affected by emotional and bodily states.
• Previous research indicates heartbeat timing (cardiac phase) can alter duration judgments.
• Specifically, stimuli during cardiac systole may seem shorter than during diastole.

Purpose of the Study:

• To investigate the neural basis of cardiac-phase effects on time perception using electroencephalography (EEG).
• To examine how cardiac-phase effects interact with the emotional content of stimuli.
• To determine if cardiac signals modulate cortical processing related to time perception.

Main Methods:

• Two experiments using EEG to record brain activity.
• Participants judged the duration of neutral visual stimuli (Experiment 1) and neutral vs. fearful faces (Experiment 2).
• Stimuli were presented during either cardiac systole or diastole.

Main Results:

• No consistent group-level behavioral cardiac-phase effect was observed.
• EEG data revealed cardiac-phase modulation of late visual activity, specifically during systole.
• Increased cortical negativity during systole predicted temporal underestimation across both experiments, even with emotional stimuli.
• Fearful faces were perceived as shorter and elicited enhanced N170-like negativity, but this was independent of cardiac phase.

Conclusions:

• A systole-specific neural mechanism, where reduced cortical activity predicts temporal contraction, is consistently observed.
• This mechanism suggests cardiac signals shape duration perception via transient cortical modulation.
• Emotional salience appears to be a stronger driver of duration perception than cardiac phase, though the systole-specific neural effect persists.