Differentiation of suprahyoid activity patterns during swallowing of umami-tasting foods

In the preceding study, the present authors differentiated the activity patterns of the suprahyoid (SH) muscles during pharyngeal swallowing of tasty and tasteless foods by using "T-P" values that assigned activity of electromyograms (EMG) to a standardized time scale. In the present study, we calculated not only the T-P values but also the In-P values (by subtracting the preceding TP-10 values from T-P) to analyze activity patterns of the SH EMG during pharyngeal swallowing of foods dissolved in unitary (monosodium glutamate [MSG] and disodium inosine-5'-monophosphate [IMP]) and binary (MSG + IMP) "umami-" tasting solutions of low and high concentration. We found that SH activity patterns differed slightly between low and high concentration of unitary and binary umami-tasting foods, but that SH activity patterns measured while swallowing umami-tasting foods did not differ from those measured while swallowing sweet- or salty-tasting foods, or tasteless food.