Published papers

It is important to prevent hypertension, which is a risk factor for cardiovascular disease and severe COVID-19. In addition, as more people work from home, it is desirable to improve intellectual productivity at home. Therefore, in this study, we clarify the effects of the thermal insulation performance of houses on physiological responses and productivity in remote workers. We obtained the following findings. (1) When insulation performance was higher, systolic blood pressure was lower, and the skin temperature and the blood flow rate of the feet were higher; (2) As insulation performance increased, productivity increased.

This study aimed to analyze how differences in piano techniques affect the KANSEI of music listeners. A prior timbre analysis of piano techniques was conducted using frequency analysis to investigate the effects of differences in performance techniques on music listeners; however, it was not possible to clearly capture the nuanced differences in performance techniques. It was found that even though the differences in the expressions and textures of sound could not be analyzed by frequency analyses, they did provide different psychological impressions to music listeners. To evaluate the impressions formed based on performance methods, we conducted KANSEI measurements using a simple electroencephalograph and an impression evaluation experiment using the semantic differential (SD) method. Our findings suggest that music listeners’ KANSEI, resulting from differences in performance methods, is related to changes in the tune of music.

It is important to prevent hypertension, which is a risk factor for cardiovascular disease and severe COVID-19. In addition, as more people work from home, it is desirable to improve intellectual productivity at home. Therefore, in this study, we clarify the effects of the thermal insulation performance of houses on physiological responses and productivity in remote workers. We obtained the following findings. (1) When insulation performance was higher, systolic blood pressure was lower, and the skin temperature and the blood flow rate of the feet were higher; (2) As insulation performance increased, productivity increased.

The autonomic nervous system plays a crucial role in the maintenance of homeostasis. Neurogenic inflammation due to decreased stability of tear film may induce changes in autonomic nerve activity, which could be associated with symptom expression.This study aimed to measure biological parameters that represent autonomic nerve activity in dry eye (DE)s caused by tear film dysfunction and investigate their relationship with symptom intensity. This prospective, cross-sectional, comparative study evaluated 34 eyes of 34 participants (mean age: 52.5 ± 13.4 years; range: 20–81 years) without keratoconjunctival damage. Nineteen eyes in the DE group showed DE symptoms and tear break-up time (TBUT) of ≤5 seconds (short TBUT DE); the 15 eyes in the non-DE group showed no DE symptoms. Autonomic nerve activity was measured for 10 minutes—starting and ending 5 minutes before and after instilling ophthalmic solution—and evaluated using the low-frequency component (LF) to the high-frequency component (HF) ratio of heart rate variability (autonomic balance). The pre-ophthalmic solution administration LF/HF ratio was not significantly different (P = 0.59) between the two groups, however, the standard deviation of the LF/HF ratio (LF/HF-SD) tended to be higher in the DE group than that in the non-DE group (P = 0.086). The DE symptom intensity was significantly related to LF/HF-SD (P = 0.005), which significantly decreased after ophthalmic solution administration in the DE group (P = 0.04). The large fluctuations in autonomic balance may be key for the understanding of the mechanism underlying DE symptoms.

Introduction The complex nature of neurocognitive impairment in schizophrenia has been discussed in light of the mixed effects of antipsychotic drugs, psychotic symptoms, dopamine D2 receptor blockade, and intelligence quotient (IQ). These factors have not been thoroughly examined before. Methods This study conducted a comprehensive re-analysis of the CATIE data using machine learning techniques, in particular Conditional Inference Tree (CTREE) analysis, to investigate associations between neurocognitive functions and moderating factors such as estimated trough dopamine D2 receptor blockade with risperidone, olanzapine, or ziprasidone, Positive and Negative Syndrome Scale (PANSS), and baseline IQ in 573 patients with schizophrenia. Results The study reveals that IQ, age, and education consistently emerge as significant predictors across all neurocognitive domains. Furthermore, higher severity of PANSS-negative symptoms was associated with lower cognitive performance scores in several domains. CTREE analysis, in combination with a genetic algorithm approach, has been identified as particularly insightful for illustrating complex interactions between variables. Lower neurocognitive function was associated with factors such as age>52 years, IQ<94/95,<12/13 education years, and more pronounced negative symptoms (score<26). Conclusions These findings emphasize the multifaceted nature of neurocognitive functioning in patients with schizophrenia, with the PANSS-negative score being an important predictor. This gives rise to a role in addressing negative symptoms as a therapeutic objective for enhancing cognitive impairments in these patients. Further research must examine nonlinear relationships among various moderating factors identified in this work, especially the role of D2 occupancy.

Purpose : Violet light (VL) is a part of natural sunlight with shorter wavelength than blue light and recently found to be beneficial for various parts of human health. However, the connection between VL and sleep is yet to be explored. This pilot study aims to elucidate the connection between VL and sleep quality with the hope to verify the potential effectiveness of VL therapy on sleep disorders. Methods : Two experiments with similar protocol were conducted. The participant was instructed to arrive before 9AM with minimal exposure to sunlight. Then, they were instructed to perform a regular deskwork for three hours, from 09:10 until 12:10. During the night, their sleep was measured using apple watch. For the first experiment, the participants were 6 university students (M/F ratio 1:1) with experiment duration of 5 days (3 Intervention, 2 Control). For the second experiment, a university student (female) performed the experiment for 2x28 days, one as control period and the other 28 days as intervention period. The main measures of this study are body temperature (only for experiment 1) and sleep stages. Results : For experiment 1, the body temperature differences show that the body temperature is higher before sleep compared to the sleep during the intervention periods as opposed to increasing temperature during control period. REM/NREM stages are also closer to ideal during the intervention periods, although there was no statistical significance. Statistical significance between sleep stages was found in the experiment 2, with higher N1, N3 and lower WK, REM ratio during intervention periods. Conclusions : In this study, the relation between VL therapy and sleep quality was analyzed. Although potential improvement to sleep quality can be seen from both short-term and long-term experiment, there is also a concern of significantly lower REM percentage during long-term experiment.

The autonomic nervous system plays a crucial role in the maintenance of homeostasis. Neurogenic inflammation due to decreased stability of tear film may induce changes in autonomic nerve activity, which could be associated with symptom expression. This study aimed to measure biological parameters that represent autonomic nerve activity in dry eye (DE)s caused by tear film dysfunction and investigate their relationship with symptom intensity. This prospective, cross-sectional, comparative study evaluated 34 eyes of 34 participants (mean age: 52.5 ± 13.4 years; range: 20–81 years) without keratoconjunctival damage. Nineteen eyes in the DE group showed DE symptoms and tear break-up time (TBUT) of ≤5 seconds (short TBUT DE); the 15 eyes in the non-DE group showed no DE symptoms. Autonomic nerve activity was measured for 10 minutes—starting and ending 5 minutes before and after instilling ophthalmic solution—and evaluated using the low-frequency component (LF) to the high-frequency component (HF) ratio of heart rate variability (autonomic balance). The pre-ophthalmic solution administration LF/HF ratio was not significantly different (P = 0.59) between the two groups, however, the standard deviation of the LF/HF ratio (LF/HF-SD) tended to be higher in the DE group than that in the non-DE group (P = 0.086). The DE symptom intensity was significantly related to LF/HF-SD (P = 0.005), which significantly decreased after ophthalmic solution administration in the DE group (P = 0.04). The large fluctuations in autonomic balance may be key for the understanding of the mechanism underlying DE symptoms.

Dorsal raphe (DR) 5-HT neurons regulate sleep–wake transitions. Previous studies demonstrated that single-unit activity of DR 5-HT neurons is high during wakefulness, decreases during non-rapid eye movement (NREM) sleep, and ceases during rapid eye movement (REM) sleep. However, characteristics of the population-level activity of DR 5-HT neurons, which influence the entire brain, are largely unknown. Here, we measured population activities of 5-HT neurons in the male and female mouse DR across the sleep–wake cycle by ratiometric fiber photometry. We found a slow oscillatory activity of compound intracellular Ca2+ signals during NREM sleep. The trough of the concave 5-HT activity increased across sleep progression, but 5-HT activity always returned to that seen during the wake period. When the trough reached a minimum and remained there, REM sleep was initiated. We also found a unique coupling of the oscillatory 5-HT activity and wideband EEG power fluctuation. Furthermore, optogenetic activation of 5-HT neurons during NREM sleep triggered a high EMG power and induced wakefulness, demonstrating a causal role of 5-HT neuron activation. Optogenetic inhibition induced REM sleep or sustained NREM, with an EEG power increase and EEG fluctuation, and pharmacological silencing of 5-HT activity using a selective serotonin reuptake inhibitor led to sustained NREM, with an EEG power decrease and EEG fluctuation. These inhibitory manipulations supported the association between oscillatory 5-HT activity and EEG fluctuation. We propose that NREM sleep is not a monotonous state, but rather it contains dynamic changes that coincide with the oscillatory population-level activity of DR 5-HT neurons.

In recent years, flying car (Urban Air Mobility, UAM) technologies have been actively studied in Japan and other countries. However, the social acceptability of flying vehicles such as UAM and drones (Unmanned Aircraft Systems, UAS) has not been extensively investigated. Social issues often arise when social acceptance is neglected. Thus, novel issues are expected to arise upon the advent of the so-called Aerial Industrial Revolution because of the industrial use of drones and the commercialization of flying cars. To overcome these issues, herein, the social acceptability of this revolution may be evaluated by two different approaches: real-time evaluation by electroencephalograph (EEG) measurement using a Kansei analyzer and social-psychological evaluation by using a questionnaire. However, at this stage, the applicability of the Kansei analyzer for the evaluation has not yet been fully addressed. Thus, in this study, an experiment was conducted to verify the applicability of the Kansei analyzer. In this experiment, subjects answered a questionnaire after hearing some noises. The effects of four types of sounds and three levels of volume on the noise-induced stress levels were investigated. This study described the results and consideration about the experiment to evaluate noise-induced stress among participants and confirmed that the Kansei analyzer is applicable for such stress detection. Moreover, the differences of results in both approaches were revealed.

In recent years, attempts have been made to quantify human emotions and sensibilities. We have proposed a technique for acquiring emotions and sensibilities from EEG in real time, and have made various applications. In particular, a wide variety of measurement methods and evaluation methods that is important in handling the brain or its activity. We are studying emotional analysis using mice from studies such as differences due to gender and national differences. In particular, emotions and sensibilities are one of the higher-order functions of human beings, and sensibility is a research area that should continue to be important in the future because research has begun in Japan. This paper describes the background and method of doing this, and mentions future prospects.

本論文の目的は、空気環境が脳波に与える影響を明らかにした上で、更に日常生活にどのような影響を及ぼすかを明らかにすることである。我々は空気環境の違いが脳に与える影響、感情や感性に与える影響、そさらには日常生活に与える影響を明らかにすべく、一般に空気の浄化を行うことができると言われるイオン発生機に着目し、イオンのある空気と脳波の関係を明らかにする。更に屋外の自然環境と室内環境間での脳波の比較も行いその変化を確認することで、より広範囲における空気環境の脳波に与える影響を明らかにする。