Chew on this: Mouth-and-Mind training may boost brain and bite

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Adults aged 50 years or above; 2. Cantonese speaking; 3. Having oral frailty, which is defined as having at least two of the following components by Oral Frailty Five-item Checklist (OF-5): (i) Natural teeth fewer than 20, (ii) Have any difficulties eating tough foods now compared with 6 months ago; (iii) Have choked on tea or soup recently; (iv) Often experience having a dry mouth, and (v) Oral diadochokinetic /ta/ sound \<6.0 times/second; 4. Having subjective cognitive decline (SCD), which refers to self-reported experience of worsening or more frequent confusion or memory loss in the past 12 month, or having been diagnosed with mild or moderate cognitive impairment; defined as a score of 0.5, 1, or 2 on Clinical Dementia Rating (C.D.R) scale; 5. Living independently or with partial assistance, defined as a score of Modified Barthel Index score greater than 60 out of 100; 6. Right-handed person to minimize variability in cortical activation patterns during fNIRS measurement; 7. Can understand the purpose and contents of this project and could give written consent. Exclusion Criteria: 1. Have attended the dental clinics for dental treatment or received orofacial myofunctional therapy (OMT), involving doing certain oral exercises with cheeks, tongue, or lips in previous 6 months; 2. Have received other cognitive training in previous 6 month; 3. Have impaired vision or hearing capacity that cannot understand the training instructions; 4. Have a diagnosis of a neurological or psychiatric condition that could affect cognitive function; 5. Have terminal illness, Temporomandibular joint dysfunction (TMJ) disorders; Sjogren's (SHOW-grins) syndrome; 6. Have undergone glossectomy surgery; 7. have been taking drugs that affect cognitive function (e.g. Benzodiazepines, antidepressants, central nervous drugs).