2. Heart-brain interactions
To optimally adapt to constantly changing environments, our internal and external milieus are coupled: bodily signals (e.g., proprioceptive or interoceptive / viscerosensory) are continuously integrated with exteroceptive sensory input (e.g., visual or auditory).
The bidirectional communication between the heart and the brain constitutes a major body-brain axis. In collaboration with other groups in the department (Somatosensory, NID), we study brain-heart coupling and its link to mental phenomena, particularly emotions or stress.
The heartbeat also influences how we perceive our environment and how we interact with it. We investigate such cardiac cycle time effects in the visual, somatosensory, and motor domain. The cardiac cycle can be divided into systole, when the heart muscle contracts to eject blood into the arteries, and diastole, when the heart (re-)fills with blood.
We found that people are more likely to prompt a briefly presented photo they’re asked to memorize during systole compared to diastole. The functional relevance of this bias is still unclear as this preference did not influence how well they remembered it (Kunzendorf et al., 2019).
In several independent studies, we also observed that near-threshold somatosensory stimuli are more likely to be detected when they are presented at later phases of the cardiac cycle (diastole)
Key publications:Motyka, P., Grund, M., Forschack, N., Al, E., Villringer, A., & Gaebler, M. (2019). Interactions between cardiac activity and conscious somatosensory perception. Psychophysiology, 56(10), e13424.Al, E., Iliopoulos, F., Forschack, N., Nierhaus, T., Grund, M., Motyka, P., Gaebler, M., Nikulin, V. V., & Villringer, A. (2020). Heart–brain interactions shape somatosensory perception and evoked potentials. PNAS, 201915629.