Published papers

Background Postoperative delirium is common in older adults following spinal surgery, yet current EEG-based detection methods rely on broad conventional frequency bands that may obscure clinically meaningful oscillatory changes. More granular spectral approaches may reveal candidate frequency-specific features that could improve diagnostic performance. Methods We recorded single-electrode frontal EEG (Fp1) from 47 patients at four perioperative timepoints and compared traditional band-level power with high-resolution 1-Hz spectral analysis (1–45 Hz). Group differences were evaluated using non-parametric statistics with FDR correction, and diagnostic accuracy was assessed using AUROC and threshold-optimized metrics. All diagnostics thresholds were derived and evaluated in the same dataset. Results Seven patients (14.9%) developed delirium. Conventional band analysis detected only reduced theta power during active delirium (|r| = 0.31; AUROC = 0.53). In contrast, 1-Hz analysis revealed a richer pattern: elevated 1-Hz power (|r| = 0.27), reduced 3–7 Hz power (|r| = 0.25–0.27), and increased 14–15 Hz power (|r| = 0.22–0.26). The 23-Hz narrow-band feature achieved the best discrimination (AUROC = 0.74), despite showing no significant effect within the traditional beta band (12–30 Hz). Several frequencies remained altered even after clinical resolution of delirium. Conclusions In this exploratory analysis, high-resolution spectral analysis identified candidate frequency-specific EEG features that distinguished delirium cases more accurately than conventional frequency bands in this cohort. Broadband averaging may not detect frequency-specific oscillatory patterns; adopting finer spectral resolution could enhance the utility of single-channel EEG for routine clinical monitoring.

In today’s fast-paced and demanding working society, promoting wellbeing has become increasingly important. While sleep quality is widely recognized as a critical determinant of wellbeing, the specific pathways linking the two remain underexplored, particularly in high-stress occupational settings. Understanding these associations may enable the development of more effective strategies for promoting wellbeing in this population. Recently, work performance (presenteeism) has garnered attention for its potential intermediary role, as it may play a pivotal role in supporting employees’ wellbeing. At the same time, work performance itself is known to be closely related to sleep disturbances. However, the mediating effect has not been thoroughly examined. This study aimed to investigate whether presenteeism serves as a link in the association between sleep quality and wellbeing in a working population. A total of 129 high-stress office workers in Japan participated in this observational study. Sleep quality, presenteeism, and wellbeing were assessed using validated measures, and mediation analysis was conducted using the PROCESS macro with bootstrap samples to estimate indirect associations. Results revealed associations between sleep quality and presenteeism (r = − 0.306, p < 0.01), as well as between sleep quality and wellbeing (r = − 0.213, p < 0.01), indicating that poorer sleep (i.e., higher PSQI scores) was linked to both higher presenteeism (lower performance) and reduced wellbeing. Furthermore, presenteeism was found to statistically mediate the association between sleep quality and wellbeing. Even after adjusting for multiple covariates (age, sex, years of service, weekly working hours, occupational position, smoking status, and alcohol consumption), a significant indirect association was observed (Estimate = −0.446, 95% CI [−0.919, −0.072]). These findings suggest that the importance of work performance as a potential intermediary factor between sleep and wellbeing among high-stress workers. This study provides novel insights into the occupational mechanisms associated with sleep quality and wellbeing and highlights the importance of addressing presenteeism as a critical intervention target in occupational health.

Audio-visual combinations in multimedia contents give us more exciting experiences than only audio or visual information. To support audio-visual video creators, affective impressions of audio-visual contents have been explored to date. However, little research has analyzed in terms of structures or features of audio-visual contents. Revealing relationships between audio-visual impressions and their structures or features can be helpful for video creators. The current study aims to analyze effects of music on image impression in terms of musical features. Specifically, we asked participants to rate impressions for image stimuli at two conditions in which image-only stimuli or music-image combination stimuli were presented. Three factors representing image impressions were extracted by factor analysis, and differences of factor scores between two conditions were calculated to describe impression changes by music. We confirmed relationships between impression changes and musical features (e.g. volume, pitch, and timbre) by ridge regression analysis. As a result, regression analysis accounted for high variances in amount of impression changes and revealed that some musical features influenced on image impressions. This study provides a feasibility of estimating image impressions by musical features.

In recent years, flying cars have been actively researched both in Japan and abroad. However, little research has been carried out on the social acceptance of flying vehicles. Social problems often arise when neglecting the social acceptance. It is expected that problems will arise in the future when “Aerial Industrial Revolution” occurs due to industrial use of drones and commercialization of flying cars. In this study, the social acceptance is evaluated by two approaches. One is real-time evaluation by Kansei-analyzer and the other is social psychological evaluation by questionnaire. But the applicability of Kansei-analyzer to the evaluation has not been fully addressed yet. Then this study conducts two kinds of experiments to clarify the applicability of Kansei-analyzer. This paper describes the results and consideration about the experiments to evaluate stress on noise.