Methods: The brain activity of six healthy adults (three males, three females; mean age = 31.5 ± 7.3 years)was determined by multi-channel NIRS instrument (Spectratech OEG-16, Spectratech Inc., Tokyo, Japan) measuring cerebral blood flow (CBF). The twelve arrays were aligned at two lines and 6 rows on the head module at 3 cm interval. Every two array was mounted by incident or detection fibers. The probes were placed to the subject’s forehead during experiments. To get the subject’s cognitive brain function, the protocols for eating behaviors were determined. A: Before and during eating the subjects kept opening the eyes, and then ate jelly after an examiner gave the verbal instruction to open the mouth for eating. B: Before and during eating the subjects kept closing the eyes, and then ate jelly after the instruction mentioned above. C: Before and during eating the subjects kept closing the eyes, and then jelly was served with a spoon but not instruction was given. Each task session was carried out 5 times for each subject.
Results: By each channel composed of a pair of incident and detect ion fibers, we have measured a time till reaching CBF peak value since starting to eat. There was no significant difference of the duration among task protocol A, B and C in averages of the subjects. However, in intrapersonal data, the time until reaching peak, in task protocol A was shorter than in B (p<0.05) in two subject. In one subject, the time as mentioned above in task protocol B was shorter than in A (p<0.05)
Conclusions: Both sight and verbal information improved the cognition in two subjects. Moreover one subject showed the importance of only caregiver’s verbal instruction rather than prediction by sight.