Hand posture affects brain-function measures associated with listening to speech.

A major difficulty in studies of the brain, from the molecular to large-scale network level, is ensuring the accuracy and reliability of results, since repeatability has been a problem in studies utilizing functional magnetic resonance imaging (f-MRI) near-infrared spectroscopy (NIRS), and positron-emission tomography (PET). More generally, an effort to replicate psychological studies has shown that the original results were unambiguously reobtained only 39% of the time. It has been suggested that researchers must undertake studies to identify factors that reduce reliability and conduct more carefully controlled studies to improve reliability. In our previous work, we examined whether changes in hand/arm posture can have a confounding effect on task-related brain activity. Here we show a solution to enhance reproducibility in a NIRS study in a hearing task. The results showed that crossed posture can lead to different results than parallel posture with respect to asymmetric functional connectivity, especially during non-resting state. Even when the only task is listening to speech stimuli, participants should be asked to place their hands on a surface and feet on the floor and keep the same stable posture to increase reproducibility of results. To achieve accurate reliability and reproductively of results, stable hand posture through the experiment is important.

Vocal Hygiene Education Program Reduces Surgical Interventions for Benign Vocal Fold Lesions: A Randomized Controlled Trial.

OBJECTIVES/HYPOTHESIS: Vocal fold polyps and nodules are common benign laryngeal lesions. Currently, the Japanese health insurance system covers surgical interventions. However, the establishment of more cost-effective conservative methods is required, because healthcare costs are viewed as a major concern, and the government and taxpayers are demanding more economical, effective treatments. In this situation, more suitable vocal hygiene education may be important for the success of cost-effective conservative treatment. In this study, we developed a novel reinforced vocal hygiene education program and compared the results of this program with those of previous methods of teaching vocal hygiene. STUDY DESIGN: Multicenter randomized controlled trial. METHODS: Patients who visited a National Hospital Organization (NHO) hospital for the surgical indication of hoarseness were included in the study. Before undergoing surgery, 200 patients with benign vocal fold lesions (vocal fold polyps/nodules) were enrolled and randomly allocated to the NHO-style vocal hygiene educational program (intervention group) or control education program (control group). Two months after enrollment, the patients in both groups underwent laryngeal fiberscopic examinations to determine whether the benign lesions had resolved or whether surgery was indicated for the vocal fold polyps/nodules. RESULTS: After 2 months, in the intervention group, the proportion of lesion resolution (61.3%) was significantly greater than that in the control group (26.3%) (P < .001, Fisher exact test). CONCLUSIONS: Our results clearly indicate that the quality and features of the education program could affect the outcome of the intervention. We found that a reinforced vocal hygiene education program increased the rate of the resolution of benign vocal fold polyps and nodules in a multicenter randomized clinical trial. LEVEL OF EVIDENCE: 1b Laryngoscope, 2593-2599, 2018.

Independent exercise for glottal incompetence to improve vocal problems and prevent aspiration pneumonia in the elderly: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of a self-controlled vocal exercise in elderly people with glottal closure insufficiency. DESIGN: Parallel-arm, individual randomized controlled trial. METHODS: Patients who visited one of 10 medical centers under the National Hospital Organization group in Japan for the first time, aged 60 years or older, complaining of aspiration or hoarseness, and endoscopically confirmed to have glottal closure insufficiency owing to vocal cord atrophy, were enrolled in this study. They were randomly assigned to an intervention or a control group. The patients of the intervention group were given guidance and a DVD about a self-controlled vocal exercise. The maximum phonation time which is a measure of glottal closure was evaluated, and the number of patients who developed pneumonia during the six months was compared between the two groups. RESULTS: Of the 543 patients enrolled in this trial, 259 were allocated into the intervention group and 284 into the control; 60 of the intervention group and 75 of the control were not able to continue the trial. A total of 199 patients (age 73.9 ±7.25 years) in the intervention group and 209 (73.3 ±6.68 years) in the control completed the six-month trial. Intervention of the self-controlled vocal exercise extended the maximum phonation time significantly ( p < 0.001). There were two hospitalizations for pneumonia in the intervention group and 18 in the control group, representing a significant difference ( p < 0.001). CONCLUSION: The self-controlled vocal exercise allowed patients to achieve vocal cord adduction and improve glottal closure insufficiency, which reduced the rate of hospitalization for pneumonia significantly. CLINICAL TRIAL: gov Identifier-UMIN000015567.

Near-infrared-spectroscopic study on processing of sounds in the brain; a comparison between native and non-native speakers of Japanese.

Conclusions The result suggested that mother tongue Japanese and non- mother tongue Japanese differ in their pattern of brain dominance when listening to sounds from the natural world-in particular, insect sounds. These results reveal significant support for previous findings from Tsunoda (in 1970). Objectives This study concentrates on listeners who show clear evidence of a 'speech' brain vs a 'music' brain and determines which side is most active in the processing of insect sounds, using with near-infrared spectroscopy. Methods The present study uses 2-channel Near Infrared Spectroscopy (NIRS) to provide a more direct measure of left- and right-brain activity while participants listen to each of three types of sounds: Japanese speech, Western violin music, or insect sounds. Data were obtained from 33 participants who showed laterality on opposite sides for Japanese speech and Western music. Results Results showed that a majority (80%) of the MJ participants exhibited dominance for insect sounds on the side that was dominant for language, while a majority (62%) of the non-MJ participants exhibited dominance for insect sounds on the side that was dominant for music.

Brain activity in aphonia after a coughing episode: different brain activity in healthy whispering and pathological aphonic conditions.

A 48-year-old woman visited the authors' clinic because of aphonia. Laryngeal fiberscopic examination indicated laryngitis and bronchitis, and the authors recognized glottal incompetence when she tried to phonate. The authors performed a functional magnetic resonance imaging (f-MRI) study on the patient's first visit to their clinic and a second study 35 days after the first visit (30 days after the bronchitis and coughing had completely resolved). The brain activity shown on f-MRI differed markedly in the ordinary speaking and whispering phonation modes at the second visit. This suggests that whispering and pathological aphonia result from completely different brain activity, at least in this specific patient.

An fMRI study of whispering: the role of human evolution in psychological dysphonia.

Humans are the only species known to use whispering for communication, and humans are also the only species known to suffer from functional (psychological) aphonia, a condition in which only whispered and not vocalized speech can be produced. Thus, whispering is uniquely a human function and psychological aphonia is uniquely a human dysfunction; both can be considered to result from human evolution. We hypothesize that the human brain has developed one or more identifiable switching mechanisms that overlay whispering onto the mechanisms of normal speech production. Thus, for whispering the speech production system operates as for normal speech production, but the switch to whispering activates the laryngeal abductor muscle (and possibly the inferior pharyngeal constrictor) so that the larynx does not completely adduct and turbulence noise is produced at the larynx. We hypothesize that psychological aphonia results from involuntary or subconscious activation of this switching mechanism. Preliminary research leads us to hypothesize that there are two switching mechanisms. This research used functional magnetic-resonance imaging to contrast brain activity for both normal speech and whispering (versus silence) for normally phonic subjects in an imagined social situation. One pattern of results involved a decrease of overall activity for whispering, with possible activation of the corpus callosum, and possible crossover of the main locus of activation from the dominant to the nondominant side. The other involved increased overall activity for whispering versus normal voice, accompanied by an increase of activity in the frontal cortex. More participants exhibited the former pattern than the latter one. These results may be related to the fact that there are actually two types of psychological aphonia, one that occurs after bouts of severe coughing associated with lower-respiratory disorders and the other due to purely psychological factors. We hypothesize that these are associated with the two different switching mechanisms, an upper one associated with the conscious brain and a lower one associated with more basic functions such as protecting the vocal folds. Understanding brain mechanisms for voluntary whispering and relating them to the occurrence of dysphonia has obvious implications for improving clinical assessment and treatment of aphonia, and would also contribute to improved understanding of human function in general.

Novel diagnostic device for oral and pharyngeal examinations of children: folding-scope for the oral and pharyngeal cavities.

Although children may dislike and/or resist oral and pharyngeal examination with a tongue depressor, they enjoy lollipops on sticks, eating with spoons, forks, and chopsticks, and brushing their teeth. Many reports have noted this apparent contradiction, since paediatric patients are often treated after toothbrushes or chopsticks penetrate the pharyngeal wall. We therefore developed a novel device to observe the inside of the mouth without using a flashlight, tongue depressor or head mirror. We previously developed the AWS for tracheal intubation through the mouth for anaesthesia and emergency situations, along with a new device to observe the inside of the oral cavity simultaneously. We have developed a new attachment to the AWS for observations inside the oral cavity and pharynx. Our newly developed oral and pharyngeal examination system is a useful tool for diagnostic examinations and may also enable treatment without causing discomfort or distress to patients and their families.

Commercially available high-speed system for recording and monitoring vocal fold vibrations.

We have developed a special purpose adaptor making it possible to use a commercially available high-speed camera to observe vocal fold vibrations during phonation. The camera can capture dynamic digital images at speeds of 600 or 1200 frames per second. The adaptor is equipped with a universal-type attachment and can be used with most endoscopes sold by various manufacturers. Satisfactory images can be obtained with a rigid laryngoscope even with the standard light source. The total weight of the adaptor and camera (including battery) is only 1010 g. The new system comprising the high-speed camera and the new adaptor can be purchased for about $3000 (US), while the least expensive stroboscope costs about 10 times that price, and a high-performance high-speed imaging system may cost 100 times as much. Therefore the system is both cost-effective and useful in the outpatient clinic or casualty setting, on house calls, and for the purpose of student or patient education.

A magnetoencephalographic study of Japanese vowel processing.

Magnetic brain responses were recorded to clarify the cortical representation of vowel processing in Japanese. We investigated the peak latencies and equivalent current dipoles of the auditory N1m responses to the Japanese vowels [a], [i], [o], and [u]. In intraindividual analyses for a single participant, well-replicated results for the dipole parameters supported the existence of phoneme-specific cortical maps for vowels. In the interindividual analyses for the eight participants, [a] and [i] elicited significantly earlier N1m responses than [u], and the dipole for [i] was more posteriorly oriented than [a] in the left hemisphere. The results of the current study suggest left hemispheric predominance in vowel processing and that factors associated with a different language system may modify the cortical map.

Neuromagnetic responses to binaural beat in human cerebral cortex.

The dichotic presentation of two sinusoids with a slight difference in frequency elicits subjective fluctuations called binaural beat (BB). BBs provide a classic example of binaural interaction considered to result from neural interaction in the central auditory pathway that receives input from both ears. To explore the cortical representation of the fluctuation of BB, we recorded magnetic fields evoked by slow BB of 4.00 or 6.66 Hz in nine normal subjects. The fields showed small amplitudes; however, they were strong enough to be distinguished from the noise accompanying the recordings. Spectral analyses of the magnetic fields recorded on single channels revealed that the responses evoked by BBs contained a specific spectral component of BB frequency, and the magnetic fields were confirmed to represent an auditory steady-state response (ASSR) to BB. The analyses of spatial distribution of BB-synchronized responses and minimum-norm current estimates revealed multiple BB ASSR sources in the parietal and frontal cortices in addition to the temporal areas, including auditory cortices. The phase of synchronized waveforms showed great variability, suggesting that BB ASSR does not represent changing interaural phase differences (IPD) per se, but instead it reflects a higher-order cognitive process corresponding to subjective fluctuations of BB. Our findings confirm that the activity of the human cerebral cortex can be synchronized with slow BB by using information on the IPD.