Respiration, Heartbeat, and Conscious Tactile Perception

Area of Science:

• Neuroscience
• Psychology
• Physiology

Background:

• Sensory perception is influenced by the cardiac cycle.
• Respiration and cardiac activity are naturally coupled.
• The joint influence of respiration and cardiac activity on tactile perception requires investigation.

Purpose of the Study:

• To investigate the combined effects of respiration and cardiac activity on tactile perception.
• To determine how participants adapt their respiratory cycle to optimize tactile detection.
• To explore the relationship between respiratory-cardiac coupling and tactile performance.

Main Methods:

• Recruited 41 healthy participants for a tactile detection task.
• Recorded electrocardiography, respiratory activity, and finger photoplethysmography.
• Analyzed tactile detection rates, decision confidence, and physiological signals in relation to respiratory and cardiac cycles.

Main Results:

• Participants synchronized respiration to expected stimulus onsets, coinciding with peak heart rate and likely heightened cortical excitability.
• Tactile detection was highest in the early expiratory phase and during cardiac diastole.
• Detection rates correlated positively with respiratory phase-locking and cardiac cycle modulations.
• A minimum detection rate was observed approximately 250-300 ms after the R-peak, correlating with pulse wave arrival.

Conclusions:

• Respiration and cardiac signals are integrated to optimize tactile detection performance.
• Respiratory phase-locking to expected stimuli enhances performance, suggesting cognitive modulation.
• Tactile perception varies across the cardiac cycle, with effects likely stemming from cognitive processes rather than peripheral artifacts.