Neuro-respiratory Synchronization: Connecting Brainwaves and Breath for Cognitive Harmony - Narrative Review

The scientific community is actively exploring the effects of breath-related practices on the emotional, physiological, and cognitive functioning of human beings. It is no longer the singular realm of exploration of the spiritual communities. A thorough search of PubMed, Scopus, and Google Scholar was performed to locate pertinent articles on respiratory entrainment of hippocampal waveforms and its relationship with memory. The search utilized terms such as "hippocampal waveforms," "respiratory entrainment," and "phase-amplitude coupling (PAC)," which were combined using Boolean operators (AND, OR). There is no dearth of literature indicating consolidation, retrieval, and escalation of memory encoding with breath-related practices. However, the underlying mechanisms linking breath and brain cognition in human beings require further rigorous scientific exploration, which is still in a primitive stage. Nasal airflow during inhalation stimulates various structures in the brain and interferes with hippocampal waves. These hippocampal waves are modified by the nature of respiratory rhythm through hierarchically organized PAC. In addition, research proposes that nasal breathing organizes neuronal activity across the brain and accomplishes intricate behaviors, including memory. Apparently, as hippocampal respiration-induced rhythm tracks breathing, controlled breathing practices can be framed as an active interference mechanism to secure hold over one's mind and cognition. Hence, in this article, we discuss an overview of the emerging literature on how the physiological regulation of nasal breathing is linked with the neural and cognitive processes.