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中文Research Highlights
- Publish Date：2025-09-15
Everyday Actions, Deep Brain Connections: NYCU Study Uncovers How Chewing and Swallowing Engage the Human Mind
Professor Chia-Shu Lin from the Department of Dentistry conducts a chewing test using commercially available gummy candy.
Edited by Chance Lai
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What if every bite of rice or sip of water was more than just a reflex? Researchers from the National Yang Ming Chiao Tung University (NYCU) have discovered that these seemingly mundane actions—chewing and swallowing—are intricately linked to the brain’s complex neural networks.
In two recently published studies in the Journal of Oral Rehabilitation, NYCU’s Department of Dentistry and Magnetic Resonance Imaging (MRI) Core Laboratory reveal that these everyday functions are not just mechanical—they reflect and rely on distinct neural pathways in the brain, particularly in relation to aging and cognitive adaptation.
In the gummy candy experiment, participants with better chewing ability were able to mix the two-colored gummy more evenly.
Mapping the Brain While Chewing and Swallowing
Over a span of two years, a research team led by Professor Chia-Shu Lin from the Department of Dentistry tested more than 100 healthy adults across various age groups. While participants performed chewing and swallowing tasks, their brain activity was recorded using MRI scans to identify patterns of neural connectivity.
Under low-effort chewing conditions, researchers observed functional connections between the cerebellum and the primary sensorimotor cortex—regions responsible for movement control. However, when chewing became more difficult (such as when the subject encountered a hard-to-crush object), those with stronger functional connections in the prefrontal cortex—an area tied to high-level cognition—showed better chewing performance.
This finding suggests that effective chewing is not merely a matter of dental health or the presence of teeth; it also involves the ability to chew correctly. It also requires active engagement of the brain’s cognitive systems, particularly among older adults who are adapting to new dentures or unfamiliar food textures. In these situations, learning and adaptation—functions controlled by the prefrontal cortex—play a critical role.
In two recently published studies in the Journal of Oral Rehabilitation, NYCU’s Department of Dentistry and Magnetic Resonance Imaging (MRI) Core Laboratory reveal that these everyday functions are not just mechanical—they reflect and rely on distinct neural pathways in the brain, particularly in relation to aging and cognitive adaptation.
In the gummy candy experiment, participants with better chewing ability were able to mix the two-colored gummy more evenly.Mapping the Brain While Chewing and Swallowing
Over a span of two years, a research team led by Professor Chia-Shu Lin from the Department of Dentistry tested more than 100 healthy adults across various age groups. While participants performed chewing and swallowing tasks, their brain activity was recorded using MRI scans to identify patterns of neural connectivity.
Under low-effort chewing conditions, researchers observed functional connections between the cerebellum and the primary sensorimotor cortex—regions responsible for movement control. However, when chewing became more difficult (such as when the subject encountered a hard-to-crush object), those with stronger functional connections in the prefrontal cortex—an area tied to high-level cognition—showed better chewing performance.
This finding suggests that effective chewing is not merely a matter of dental health or the presence of teeth; it also involves the ability to chew correctly. It also requires active engagement of the brain’s cognitive systems, particularly among older adults who are adapting to new dentures or unfamiliar food textures. In these situations, learning and adaptation—functions controlled by the prefrontal cortex—play a critical role.
Swallowing: A Separate Neural Circuit
Interestingly, the neural mechanisms for swallowing appear to follow an entirely different route. The team found that successful swallowing performance was associated with enhanced connectivity between the cerebellum and the basal ganglia—areas linked to rhythmic and coordinated movement.
Contrary to popular belief, strong chewing ability does not necessarily indicate strong swallowing ability. The brain uses distinct circuits to manage these two functions.
Brain, Body, and the True Markers of Health
The study also revealed a striking correlation between neuromuscular health and oral function. Participants who performed well in both chewing and swallowing tasks had noticeably larger upper arm and lower leg circumferences—suggesting better muscle condition. In other words, the ability to both bite and swallow effectively may be a comprehensive indicator of systemic health.
Implications for Elderly Care and Interdisciplinary Medicine
“These findings underscore the critical role of oral function in overall health,” said Professor Lin, who led the research. “They also highlight the need for separate assessments of chewing and swallowing abilities in dental clinics, especially for older adults.”
Most importantly, the studies show that overcoming chewing challenges isn’t just about dental mechanics—it’s a brain-dependent process. The structure and function of the neural network significantly influence how elderly individuals adapt to eating, especially in cases involving new prostheses or complex textures.
“These results demonstrate that oral health cannot be treated in isolation,” Prof. Lin emphasized. “It must be integrated with neuroscience and geriatric medicine. Healthy aging depends not only on what we eat, but also on how we chew and swallow it.”
Professor Chia-Shu Lin, Department of Dentistry at NYCURelated Image(s)：
