Multi-Pathway Olfactory Rehabilitation: A Hypothesis Integrating Trigeminal, Respiratory, Predictive, and Interoceptive Mechanisms

Olfactory rehabilitation has largely been treated as a single-pathway problem. Standard training protocols stimulate olfactory receptor neuron regeneration through repeated exposure to odorants. The approach works, within limits. It does not engage the trigeminal chemosensory system, does not use nasal airflow as a priming mechanism despite its effect on limbic oscillations, does not account for predictive processing and familiarity in olfactory perception, and measures outcome only through smell identification — often the most compromised pathway. This paper proposes a hypothesis that addresses these gaps by integrating four mechanisms: paced nasal inhalation as a priming variable, trigeminal co-activation through TRP-active volatile compounds, use of familiar botanical scent memory to engage predictive olfactory networks, and a somatic awareness assessment that reads and amplifies residual biological activity across intact pathways.