Understanding the Dynamics of Physiological Systems Based on Biological Signals Triggered by Internal and External Stimuli: From Analysis to Application

Human physiological systems play an important role to maintain internal stability according to environmental changes. Physiological systems are known to regulate their functions by interactions between one another which may be associated with physiological homeostasis, rather than by their independent activities. Various methods have been introduced to identify different types of interactions between physiological systems using biological signals such as electroencephalogram (EEG), electromyogram (EMG), electrocardiogram (ECG) and respiratory activity. Experimental studies have found that the interactions between physiological systems occur both intra- and inter-individually. Recent findings reported that biological rhythms of physiological systems could be modulated by coupling with external (e.g. visual, auditory, vibrational) rhythmic stimuli.

Previous findings provide experimental evidence for interactions between physiological systems based on biological signals under different physiological conditions and states. However, a better understanding is necessary on how the interaction and cooperation contribute to physiological functioning and are related to activities of nervous systems. These activities are important to understand because they are directly associated not only with the functioning of physiological systems but also with our overall health. Abnormal nervous activities are related with dysfunctions in physiological systems, chronic diseases and daytime performance. Thus, further investigation is necessary on how changes in biological rhythms during interactions between physiological systems relate to the activities of nervous systems in different physiological conditions and states. The findings can be applied as a non-pharmaceutical and non-surgical solution to improve physical and mental disorders (e.g. sleep-related disorders, depression) and certain nervous system functions (e.g. memory). Further research could be extended to understand how concordance in physiological state (e.g. sleep pattern) under sharing behaviors between individuals is related with the interactions of physiological systems.

This Research Topic addresses current knowledge on dynamics of physiological systems particularly focused on the situations of internal and external stimuli. The internal stimuli could encompass changes in physiological conditions (e.g. age, disorders) and states (e.g. wake/sleep, different sleep stages) derived from natural human physiologic process or specific experimental conditions, and the external stimuli could contain physical stimuli such as visual, auditory, vibrational and electrical stimuli. We welcome submissions related to but not limited to the following sub-topics:

• Analysis on the interaction among physiological systems using biological signals under physiological conditions and states, and external stimuli;
• Methods to modulate biological rhythms with external stimuli;
• Analysis on the coupling characteristics between biological rhythms of physiological systems and external stimuli;
• Applications to improve physical and mental disorders, and functions related to physiological systems based on the modulation of biological rhythms by induced coupling with external stimuli;
• Investigation on the relation between concordance in physiological state under sharing behaviors of independent individuals and the interactions of physiological systems;
• New interpretation methods to understand physiological interaction