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The present study examined the ability of physiological parameters of chewing to discriminate between six foods of differing shapes and textural properties. Parameters were measured from masseter electromyograms, which were recorded from healthy and young subjects while they chewed the test foods. Analysis of conventional parameters showed that the number of chewing cycles dropped by 8.8 cycles upon a 100- kPa increase in food fracturability and by 6.6 cycles upon a 5.0-k J/m3 increase in food adhesiveness. Analysis of the newly developed parameters showed that a 100- kPa increase in food hardness increased the T25, T50 and T75 values by 0.015, 0.020 and 0.021 points, respectively, whereas a 100- kPa increase in the food fracturability decreased the T25 and T50 values by 0.061 and 0.070 points, respectively. The results suggest that combining several physiological parameters will enhance discrimination between foods because individual parameters are sensitive to different food properties. Practical Applications Together with other measures, analyzing the activity of the masseter, a muscle responsible for closing the jaw, can provide objective information about food texture. The present study used electromyography to examine the quantitative relationships between various physiological parameters associated with masseter activity during chewing and the textural properties of food. The study focused on everyday foods rather than the model foods that are usually tested in laboratory studies. In addition to analyzing the textural properties (such as hardness and adhesiveness) using conventional physiological parameters, we also developed new parameters, TP values, to assess the masseter activity patterns specifically. The combined use of these physiological parameters is expected to aid clinicians and the food industry in their interactions with individuals who, owing to their age and sequelae of cerebrovascular diseases, have particular difficulty verbalizing their experience of chewing foods. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine (i) whether or not textural properties of foods and body positions affect the durations of anterior tongue and suprahyoid muscle activities during swallowing, and (ii) if such changes occur, is the 'pre-peak' or the 'post-peak' duration of integrated muscle activity responsible. We used two test foods with different proprieties of hardness and adhesiveness. We recorded electromyograms (EMGs) from the anterior tongue and suprahyoid muscles as well as the laryngeal movement associated with swallowing in normal subjects (six men and three women; 21-30-years old). The subjects swallowed the test foods in four randomly set postures: upright, two inclined (60 ° and 30 ° to horizontal), and supine. None of the measured durations for the anterior tongue and suprahyoid EMGs were different among the four positions during swallowing of either food. The 'total' duration, from the start to the end of the integrated EMG, of anterior tongue activity was significantly ( P < 0·001,anova) longer during the swallowing of the tougher and more adhesive food than during swallowing of the other food, but the 'total' duration of suprahyoid activity was unchanged. The 'post-peak' duration of anterior tongue activity, which stretched from the peak to the end of the integrated EMG, was also significantly longer ( P < 0·001,anova) during swallowing of the tougher and more adhesive food. The results indicate that tougher and more adhesive foods prolong the duration, especially the 'post-peak' duration, of anterior tongue activity during swallowing in the upright, inclined and supine positions. [ABSTRACT FROM AUTHOR]

The present study examined two questions concerning the cognitive processing of Japanese loanwords borrowed from English and written in katakana. The first question was whether “interlexical activation” occurs between Japanese and English. Results from a lexical decision task showed that loanwords phonetically similar to the original English words were judged with the same speed and accuracy as those being phonetically dissimilar to their original English words. The study further examined the cognitive processing of unadopted loanwords (i.e., words unlisted in a Japanese loanword dictionary). Reaction times displayed the shortest mean for non–words, followed by pseudo–loanwords, and finally unadopted loanwords. Thus, the only time the lexical representation of an original English word was possibly activated was when native Japanese speakers had seldom seen the word in katakana. The second question was what creates the “lexical mental boundary” between adopted and unadopted loanwords. A questionnaire showed that native Japanese speakers are likely to use decision–making strategies for determining lexicality of loanwords in Japanese based on their daily experience of exposure to katakana words in print. [ABSTRACT FROM AUTHOR]

The neural control mechanism of pharyngeal constrictor (PC) activity of rabbits was examined in relation to vagal afferents. The average firing rate of single PC units of unilaterally vagotomized animals increased from 0.52 to 8.83 spikes/sec by cooling of the intact vagus nerve at 5 degrees C. Time courses of increases in PC and diaphragmatic (Dia) activities were examined during the period from the start of vagal cooling to the time when the PC reached the maximum firing rate. Although Dia activity linearly increased along with the respiratory cycles, PC activity slowly increased during the first three-quarters of the period and rapidly increased during the last quarter. The result suggests that more impulses in the vagus nerve are required to be blocked by cooling at a lower temperature for eliciting an increase in PC activity compared with that in Dia activity. The increase in PC activity evoked by bilateral vagotomy (from 0.30 to 10.07 spikes/sec) was not different from that by vagal cooling. The presumable afferent nerve fibers responsible for the increase in PC activity were discussed. [ABSTRACT FROM AUTHOR]