Heart-brain interactions shape somatosensory perception and evoked potentials.

Area of Science:

• Neuroscience
• Cognitive Science
• Psychology

Background:

• Conscious perception is influenced by internal bodily signals, such as heartbeats.
• The precise mechanisms and timing of these heartbeat-related effects on perception remain unclear.
• It is debated whether these effects stem from early sensory processing or later decision-making stages.

Purpose of the Study:

• To investigate distinct heartbeat-related influences on conscious perception.
• To differentiate between early sensory and late decisional processes in heartbeat perception.
• To establish a framework for understanding the integration of internal signals into conscious awareness.

Main Methods:

• Combined electroencephalography (EEG) and electrocardiography (ECG).
• Utilized signal detection theory (SDT) for perceptual analysis.
• Analyzed heartbeat-evoked potentials (HEP) and somatosensory-evoked potentials (SEP).

Main Results:

• Heartbeat-evoked potentials (HEP) correlated with a more conservative detection bias and reduced early/late somatosensory-evoked potential (SEP) amplitudes.
• Stimulus timing during cardiac systole decreased detection and localization accuracy, linked to reduced late SEP components.
• These cardiac cycle effects were more pronounced in individuals with stable heart rates and were independent of alpha oscillations.

Conclusions:

• Identified two distinct heartbeat-related influences on perception: one related to cardiac interoception (HEP) and another to cardiac cycle timing.
• HEP effects appear linked to early sensory processing and decision bias, while timing effects relate to perceptual sensitivity.
• Proposed a predictive coding framework integrating internal signals, like heartbeats, into conscious perception.