Takanobu Morinushi

Effect on electroencephalogram of chewing flavored gum.

Abstract The objective of the present study was to evaluate the effect on the electroencephalogram (EEG) of a chewing gum with and without our prepared new flavor. Electroencephalograms were obtained after the following three tests: chewing pure gumbase with sucrose (standard gumbase), chewing flavored standard gum and the inhalation of flavored aromatic oil. As the control, we used the pre‐stimulus control EEG record without a stimulus. We examined the relationship between the pre‐stimulus control record and the post‐stimulus record using the changes of power in four bands. Chewing the standard gumbase led to an increase in the alpha wave and a decrease in the beta wave. Chewing the flavored standard gum and inhaling the flavored aromatic oil each increased the alpha and beta waves. In addition, chewing the flavored standard gum led to a change in the ratio of theta wave in the frontal area. The difference in the theta, alpha and beta bands in chewing gum with and without the added flavor suggested that the flavor as well as chewing could induce concentration with a harmonious high arousal state in brain function.

Effects of three principal constituents in chewing gum on electroencephalographic activity

The effects of three principal constituents (sugar, spearmint, and gumbase) in chewing gum on EEG findings in 20 normal subjects were investigated. After they chewed the gumbase, theta activity decreased significantly at Fp2, O1, T3, T4, F4, P3, and Pz; alpha activity increased significantly at O1 and decreased significantly at Fp1, and beta activity increased significantly at Fp1, Fp2, O1, T3, T4, P3 and Pz. After they inhaled the spearmint, alpha activity decreased significantly at 02, F3, P4, and Fz, and beta increased significantly at 02, F3, P4, and Fz. The mean frequency of the alpha band was significantly higher than after 1 min at rest without inhalation. After the subjects chewed the gumbase with sucrose, theta activity increased at Fp2 and Fz; alpha activity increased significantly at T3; and beta activity decreased significantly at Fpl, Fp2, F4, P3, P4, Fz, and Pz. The mean frequency of the alpha band was significantly lower than after 1 min at rest without it at almost all the positions. These results suggest that the gumbase with sucrose induced relaxed concentration effects while inhalation of spearmint induced arousal effects. The chewing of gumbase showed arousal tendency.

Spectral analysis of changes in electroencephalographic activity after the chewing of gum

Abstract  The present study aimed to examine the psychosomatic effect in the chewing of marketed gum using eletroencephalogram (EEG) as an index. The EEG were taken in two sets: (i) a resting period before chewing (control recording) and a resting record (post‐resting recording) for examining reproducibility; and (ii) a control recording and resting period after gum‐chewing for 3 min (post‐chewing recording). The ratio of each frequency band to the total frequency power, the mean frequency of the alpha band and laterality of the frequency power was calculated. In the examination of the reproducibility, no statistically significant differences were observed between control recording and post‐resting recording in all indices. In the reflection of EEG after gum‐chewing, there were no significant differences between control recording and the post‐chewing recording. However, a significant interaction was observed among these indices by analysis of variance. In addition, the alpha power in the post‐chewing recording was significantly higher than that in the control recording at almost all the positions. In conclusion, the intra‐individual reproducibility of EEG was confirmed in the recording method. Furthermore, it was suggested that a significant interaction and a rising trend of the mean frequency of the alpha band after gum‐chewing reflected ‘arousal’ psychosomatic responses by the chewing of marketed gum.

Nonlinear dynamical analysis of the effect by six stimuli on electroencephalogram.

The present study investigated the search by correlation dimension (D2) for the effect of six stimuli (sucrose, spearmint, gum-base chewing as a voluntary movement, and three combinations of these stimuli) on EEG findings. Twenty normal adult subjects received sucrose, spearmint oil, gum-base alone, and three combinations of these stimuli. EEG recordings were obtained while the subjects rested quietly with their eyes closed, as the following procedure: section I, 1 minute at rest; section II, first 5-minute recording (control record); session III, each stimulus affecting for 3 minutes; session IV, 1 minute at rest; session V, 5-minute recording (poststimulus record). The EEG activity was filtered with a 0.5 Hz high pass and a 30 Hz low pass filter. The final data (epoch) for analysis were selected from all data by our epoch inducing system, and D2 was calculated using a novel analytical program. D2 was found to increase after subjects inhaled spearmint. In contrast, D2 decreased after subjects chewed gum-base and after the combination stimuli with chewing. Furthermore, the D2 change observed after each stimulus was similar to the observed D2 changes in the theta band. These findings suggest that D2 expressed the change in EEG as a brain response after each stimulus. It was also demonstrated that the change of EEG complexity as a brain response to stimulation is related to theta rhythm that might be able to produce at the cortical limbic area. We confirmed that the change observed in the complexity in response to which the chewing stimulus relates in our present study is the model that best fits that theory of the change on complexity suggested by Stam CJ.

Metal Film Sputtering Technique to Coat Teeth for Preventing Dental Caries. A Preliminary Study

Dental caries starts locally on a tooth surface; thus, the selective protection by metal films on pits and fissures is simple and effective. The method and apparatus for forming preventive coatings by sputtering are described wherein metal atoms originate in a Penning discharge space and are then guided through a duct in order to reach a tooth and then to form a spot coating on the surface. A compact-size sputtering apparatus for the coating of a gold film on a surface of extracted teeth or glass substrates has been designed and the film-deposition characteristics examined. The typical deposition rate is 1 nm/s for a 6-mm film on a glass substrate. After gold films are coated on extracted teeth, the teeth are immersed in an 0.1 mol lactic acid solution (pH=4.0). The obtained results indicate that a thickness of about 200 nm is necessary and satisfactory for protecting against dental caries in vitro.

108. Nonlinear dynamical analysis by Kaplan–Yorke Dimension of the effect by six stimuli on electroencephalograph

Two short empty time intervals (t1 & t2) between three successive auditory stimuli can be perceived as equal in 80 t1 t2 50 ms. This illusory time perception is called ‘‘temporal assimilation (TA)’’. We studied whether TA is present in the visual modality. Low contrast (20%) achromatic (black/white) and isoluminant chromatic (red/ green) sinusoidal gratings were used. t1 was changed at 240–400 ms in 40 ms step, while t2 was fixed at 400 ms. The duration of visual stimulus was set at 30 ms. t1 and t2 using black/white stimulus was perceived as equal in 80 t1 t2 40 ms, whereas in 40 t1 t2 40 ms with red/green stimulus. These results suggest that visual TA depends on the attributes of the visual stimulus. Preliminary results of ERPs during TA judgement were also reported.

Chaos analysis on brain functional change by chewing gum

Purpose: We had found out possibilities that cases with spondylotic myelopathy at middle-low cervical level (SM) could cause to intermittent dyspnea (ID). The ID was uncommon symptom of the disease without detecting any abnormalities in routine spirometry. Decompression procedure for spinal cord improved the symptom. The current purpose is that mechanisms of the symptom are examined. Subjects and method: Examinations were made of two normal subjects and four patients with SM. All the patients had complained ID and had been diagnosed by cervical MRI. Respiratory movements of thorax (RMT) and that of abdominal wall (RMA) were recorded simultaneously through two strain-gage belts rolled at nipple and navie. Subjects were laid and kept natural respiration under making their neck flat (NF) or retro flexion (NR). Results: In normal subjects, both RMT and RMA were so synchronized as to keep under the different conditions. In two patients, NR decreased velocity of only RMT. In another patient, hyperventilation was caused from NR. The other patient showed normal pattern. Conclusion: We thought that etiology of ID in SM could be two candidates; one is the dissociation between RMT and RMA and the other is hyperventilation. Both candidates could be caused on cervical cord compression.

A preliminary study on equilibrium function in the subjects with temporomandibular joint dysfunction syndrome, and anterior open bite using a stabilometer.

顎関節症発症の初発期である思春期を対象に, 顎関節症症状と平衡機能の調査を行い, 両者の関係を検討するとともに, 開咬を認める者の平衡機能についての検討も行った結果, 以下のような結論を得た.1. 対照群と比較して疼痛群では, 外周面積が5%の危険率で有意に大きく, 単位面積軌跡長が1%の危険率で有意に小さい値を示したが, いずれも時田の示した健常者の標準偏差内の値だった.2. 対照群と比較して雑音群では, 単位面積軌跡長が1%の危険率で有意に小さい値を示したが, 疼痛群と同様, 時田の示した健常者の標準偏差の範囲内の値だった.3. 対照群と比較して開咬群では, 全ての検査項目で有意差はないものの, 外周面積は大きく, 単位面積軌跡長は小さい傾向が認められた.このように, 顎関節症ならびに開咬は, 平衡機能と何らかの関係をもっている可能性が示唆された.