Chewing modulates theta oscillation and functional connectivity of the frontocentral cortex in attention and working...

There is evidence that tooth loss and reduced masticatory function are correlated with cognitive decline. We investigated cortical dynamics during attention and working memory tasks before and after self-paced chewing. Thirty healthy adults performed a visuospatial two-back task (2-Back) and visual oddball task (VO) under a 2x2 factorial design: chewing (one minute prior to the tasks) vs. no-chewing and with vs. without local anesthesia. Chewing improved behavioral measures in the 2-Back and the VO tasks. Frontocentral theta power and coherence increased post-chewing in both tasks, indicating enhanced neural synchronization. Theta frequency correlated with chewing frequency in the 2-Back test only, and early sensory P1-N1 complex of the ERP was increased post-chewing, indicating that chewing entrains and modulates task-specific theta activity and functional connectivity, possibly via a Locus Coeruleus - Thalamic - Cortical loop, tuning cognitive processing. These findings underscore the potential of masticatory activity in supporting cognitive health and suggest implications for populations with compromised oral function.