Investigating the relationship between aperiodic components of electroencephalographic and heartbeat dynamics

The quantification of functional brain-heart interplay (BHI) has traditionally been performed in the time domain or by analyzing periodic oscillatory dynamics within canonical frequency bands of electroencephalogram (EEG) and heartbeat dynamics. However, both signals also exhibit aperiodic characteristics, such as self-similarity and 1/f-like behavior. Recently, a novel model has been proposed to account for both the periodic and aperiodic components of biosignals. In this preliminary study, we investigate the functional coupling between the aperiodic components of EEG and heart period (HP) time series, hypothesizing a link between specific generators of functional aperiodic activity. Experimental results were obtained from the analysis of multimodal data collected from 20 healthy volunteers in a resting supine position. Our findings suggest the presence of significant functional coupling between the exponents of the 1/f components derived separately from EEG and HP time series. We conclude that a functional relationship exists between brain- and heartbeat- related aperiodic components in specific brain regions. Further studies are needed to investigate the physiological mechanisms and implications of this newly defined BHI dimension.