It is known that mastication increases cerebral blood flow and neuronal activities in various regions of the human brain. One hundred and eleven subjects (aged 23-84 years) were divided into a control group and two testing groups, and were examined for the effect of 10 minutes of mastication on short-term memory by using two different memory tests (A and B). Subjects were told that each test consisted of 64 pictures to memorize and 64 pictures to recall. However, they were not informed that half of the pictures to recall were the same as the pictures to memorize. First, each subject was asked to memorize 64 pictures presented one by one. Then, for testing the effect of mastication on short-term memory, subjects were asked to identify those they had previously memorized from 64 pictures to recall. When these memory tests were done before (A) and after (B) mastication, the difference between the mean (±SD) test score of A (76.8±10.1) and B (82.2±8.7) was statistically significant (Paired Rest, p<0.05). In the control group without mastication, the mean test scores for A (75.7±8.0) and B (77.7±6.2) were not statisti cally different. These results indicate that mastication significantly improves short-term memory, particularly in subjects older than 60 years old.
