We investigated the effect of chewing on maintaining memory acquisition during working
memory (WM) task using Magnetoencephalography. Eleven young-adult subjects performed
continuous two sessions of visual Sternburg tasks, each of which contains sixty trials of WM task.
Between the two sessions, subjects were instructed to perform any one of the following tasks of: (1)
stay still (STAY), (2) chew a gum without any odor and taste (GUM), (3) perform repetitive hand
exercise (HAND) for three minutes. All of the subjects showed memory load-related strong alpha
wave oscillation in the occipital area, originating from the calcarine sulcus or the parietooccipital
sulcus, during memory maintenance. The occipital alpha wave intensities were comparable between
the two sessions with GUM task, while they were significantly increased in the second session after
STAY and HAND tasks. The increases of alpha wave activity in STAY and HAND tasks were
associated with significant decreases of the concentration level in the second session. Furthermore,
accuracy rate of retrieval questions tended to increase after GUM task, while it tended to decrease and
was significantly decreased after HAND and STAY tasks, respectively. These results suggest that
chewing might be a good strategy to maintain efficient WM acquisition.