The effects of temperature and physical properties of pasty food on the swallowing characteristics and tongue surface movements of human subjects were evaluated in this study．Two kinds of pasty food were used as samples： sweet potato containing butter and carrot with an added commercial thickening agent．Physical properties (hardness and yield stress)，swallowing characteristics， and tongue surface movements were investigated at 10℃，25℃ and 50℃．Swallowing characteristics were evaluated by Scheffe's paired comparison．Swallowing frequencies were also evaluated．In ultrasound analysis of tongue movement during swallowing，the grooving depth，grooving duration and grooving width of the tongue during swallowing of samples were evaluated．The following results were obtained．

The hardness and yield stress of both samples became lower with increase in temperature．ln particular，sweet potato containing butter had signficant temperature dependence．ln sweet potato samples，the smoothness and ease of swallowing of 50℃ samples were better than those of 10℃ or 25℃ samples．ln carrot samples，the palatability of 10℃ samples was better than that of 25℃ or 50℃ samples；however，in sweet potato samples， the palatability of 50℃ samples was better than that of 10℃ or 25℃ samples． With increase in temperature， the swallowing frequencies became higher for carrot，but lower for sweet potato． The mean value of grooving depth of tongue surface movements during swallowing of sweet potato at 50℃ significantly increased compared to the value at 10℃．

Purpose： Velopharyngeal closure is essential not only for speech but also for swallowing．lt is attained to prevent air emission during speech and bolus from entering the nasal cavity during swallowing．lt has been demonstrated that the levator veli palatini muscle， the primary muscle of velopharyngeal closure for speech，is regulated to maintain tight closure in the velopharynx in accordance with strength of task loaded．However，it has not been examined how levator veli palatini muscle activity could be changed in relation to stimulus during swallowing．The purpose of this study is to exarnine whether levator muscle activity during swallowing can be changed in accordance with volume of swallowed water．

Methods： Three normal adults were used as subjects in this study．Each subject was instructed to perform five-time command swallowing of 3ml，5ml，and 10ml of water and to blow at maximum intensity．Measurement of smoothed EMG activity was made at the peak of the EMG curve for swallowing tasks and at 0.2 sec intervals for blowing tasks．

Results： The amplitude of levator activity for swallowing in each subject was variable in comparison with the activity during blowing．However，for each subject，there were no significant changes in levator muscle activity in relation to swallowed water volume．

Conclusion： Levator veli palatini muscle activity for swallowing might not change with swallowed water having a volume less than 10ml．The relationship between levator activity for swallowing and that for blowing at maximum intensity was variable across subjects．

An important aspect of swallowing disorder research is the matching of food contents with corresponding oral functions． Basic research into food texture helps clarify the relationship between food and oral function． There are many videofluorographic studies concerning food transport in the oral stage of swallowing；however，there has been little research in this area using ultrasound analysis．Ultrasound Duplex-Doppler analysis is based on the Doppler shift of the Doppler effect，which can be used to measure blood flow．This study examined depiction conditions and analysis methodology during the oral stage of swallow using the ultrasound Duplex-Doppler method．The following

results were obtained：

1． The scanning head position was standardized with certainty using an apparatus having a small fixed transducer and a holder with an angle mater．

2． Simultaneous display images were recorded in D and B modes，enabling measurement of the waveform and frequency shift produced by food transport．

3． The angle compensation line was set at 60 degrees， which made reference to the angle of inclination of the front part of palate．This provided a picture set up taking into consideration the equipment conditions．

4． The transducer angle， which was 10 degrees from the sagittal plane and convenient for front neck movement，easily provided a compensation line in agreement with the direction of food transport．

5． The position on the palate where food transport was evaluated，and the relation with the arrow of teeth，became clearer using the improved position marker．

6． This evaluation method provided the means to analyze food transport from the oral cavity to the pharynx，with regard to top velocity，inflow time， top velocity attainment time，and mean acceleration．The individual coefficient of variation for each value was small．

Based on these results， the observation and analysis of food transport using ultrasound Duplex-Doppler analysis may serve as a good model for future research．