Inclusion Criteria:  all participants were eligible to participate if they were over 20 years of age, with no known medical history of dysphagia, had an SDQ score of less than 11, indicating no suspicion for dysphagia, were able to give a written informed consent, and could follow simple verbal instructions. In addition, all participants indicated that they do not avoid eating crackers due to swallowing disorders or allergies.  Exclusion Criteria:  SDQ over 11 or medically reported dysphagia not eating crackers due to swallowing difficulty allergy to gluten