The demand for the customization of tactile sensations in rotary encoders is increasing to align with individual user preferences. In light of this objective, this study aimed to construct a tactile inference model that considers individuality with the goal of regulating targeted factor perceptions. An experimental evaluation was performed involving 17 participants to assess the tactile sensations of rotary encoders across 50 parameter settings, utilizing 30 adjective pairs. A comprehensive factor analysis of the experimental data revealed the extraction of four key factors. Subsequently, an inference model tailored to each participant was developed using neural networks and transfer-learning techniques. Furthermore, through the application of personalized tactile inference models adjusted for individual participants, we showcase the potential of selectively influencing impressions of specific factors by manipulating various physical parameters.

Kikumoto et al., 2021 investigated the impact of car seat lever-grip positions on Kansei evaluation ratings, specifically “Can be manipulated with one hand,” and found notable gender differences. Females preferred a narrower range of lever-grip positions compared to males, though their preferences overlapped. This study explored the use of electromyography (EMG) to explain Kansei rating differences related to lever-grip position and gender. EMG was measured from four muscles. Random forest regression identified that the EMG integral (iEMG) was able to predict Kansei ratings with gender-specific patterns. Multilevel modeling showed that lever-grip position, but not participant body-height, had a significant impact on iEMG, with low-Kansei-rated lever-grip positions corresponding to higher muscle loads. The findings suggest that iEMG are a valuable predictor for designing car seat levers, particularly under strict design constraints, offering insights for more ergonomically sound and Kansei-oriented vehicle design.

Conflicting evidence exists regarding the analgesic effects of massage therapy - a non-pharmacological intervention. This single-masked, randomized controlled trial, performed using a crossover design, aimed to examine the effects of local effleurage massage on pain sensitivity and emotions. Cold pain stimulus was used to evaluate stimuli to the hands of 35 healthy women. Massage effects were evaluated using pain threshold, pain tolerance, pain intensity, salivary α-amylase values, and the psychological scale Profile of Mood States (POMS). Pain tolerance was significantly longer under massage than control conditions (p < 0.05). Moreover, pain intensity exhibited a possible trend toward significance under massage conditions compared to the control conditions (p = 0.054). Psychological evaluation using the POMS also revealed a significant difference between the pre-experimental values and massage conditions values in the depression-dejection subscale (p < 0.05). These findings indicate that effleurage massage could serve as a temporary and useful anti-nociceptive strategy for patients with pain.

In the present study, two perceptual experiments were conducted with semantic differential method to clarify the affective properties of motorcycle riders and non-riders for acceleration sounds of sports-type motorcycles. In Experiment 1, the impressions of the sounds recorded under rapid and slow acceleration conditions were rated by university students. In Experiment 2, the impressions of the acceleration sounds were rated by motorcycle riders and non-riders. The results showed that the impression space for the engine sounds were illustrated by the principal components of roughness and activity. The rapid acceleration sounds were perceived more active than slow acceleration sounds and the riders were more sensitive for the activity than the non-riders. The roughness was almost consistent for the same motorcycles. Two psychophysical models of roughness and dissonance were tested to estimate the perceptual roughness of riders. The results showed that the dissonance matched to the impressions, rather than the psychophysical roughness.

Facial expression recognition influences approach-avoidance behaviors, but can these behaviors affect facial expression recognition? We conducted psychophysical experiments using virtual reality to investigate this reverse causal relationship. Participants responded to static 3D face stimuli generated by morphing expressions between happy and angry in Experiments 1 and 3. For Experiment 2, happy-fearful morphed stimuli were employed. Participants either approached, avoided, or were approached or avoided by the face. The results showed that participants recognized the face as angrier when they avoided it rather than when it avoided them (Experiment 1); as happy when approaching and fearful when avoiding, irrespective of who acted (Experiment 2); and as angrier when the face approached them rather than when they approached it if both parties were physically close (Experiment 3). These findings suggest that approach-avoidance behavior influences facial expression recognition. We posit that unconscious learning rooted in biological instincts creates this connection.

Tonality, specifically the difference between major and minor keys, plays a crucial role in emotional expression in music. Major keys typically evoke bright, optimistic feelings, while minor keys tend to elicit darker, more melancholic emotions. This study aimed to isolate the effect of tonality by utilizing “sister pieces,” in which the same musical piece is transposed from a major key to a minor key or vice versa. Six well-known classical pieces were selected, three originally in a major key and three in a minor key. Using music editing software, we transposed these tracks, resulting in six pairs of sister pieces. We then quantitatively compared emotional impressions and preferences across eight items with 20 healthy adult participants. The results demonstrated that most impressions and preferences were significantly influenced by the key changes, supporting the utility of sister pieces as an effective method for examining tonality’s impact.

This study examined the multidimensional effects of the physical, psychological, and behavioral conditions of sitting on the Wellness Nordic Relax^® Chair (WNRC) on older individuals with dementia. This study was conducted with a randomized crossover design (N = 14). Outcomes included sitting time, salivary alpha-amylase (sAMY), immunoglobulin A (IgA), visual analog scale (VAS) for comfort, and the Dementia Happy Check scale score. As a result, sitting time on the activated WNRC was significantly longer (p = 0.01) than on the non-activated WNRC. Additionally, VAS comfort score on the activated WNRC was significantly higher than on the non-activated WNRC (p = 0.03). A moderate positive correlation between sitting time and VAS comfort was found only under the activated WNRC (r = 0.563, p = 0.03). No specific trend could be found for sAMY, IgA, or the Dementia Happy Check scale score. These findings suggest that sitting on this activated WNRC induces comfort and temporary calm for older individuals with dementia.

This study aimed to examine the effects of primary and secondary market price offers on the formation of internal reference price levels and price ranges in the price decisions of sellers and buyers. The experimental results suggest that the price level is less sensitive to price information. In contrast, the price range fluctuates flexibly in response to the price level and the presented price information. Although no differences in anchoring effects based on price information were found between sellers and buyers, we identified price differentials indicating that the seller’s selling price consistently exceeded the buyer’s purchase price.

This study presents a method for quantifying the aesthetic preference of diamond videos using image features. First, we introduce an evaluation method for three types of sparkle (brilliance, scintillation, and dispersion) based on the two-dimensional discrete Fourier transform. Next, we verified the effectiveness of the proposed method by analyzing videos of 12 types of diamonds with varying refractive indices and dispersion values. As a result, the adjusted coefficient of determination R² values from the multiple regression analyses of the three types of sparkle were 0.931, 0.920, and 0.888, respectively, indicating the applicability of the proposed method. Furthermore, the adjusted R² value regarding aesthetic preference was 0.935. The refractive index and dispersion values increased the sensory evaluation values of brilliance/scintillation and dispersion, respectively, and the closer these values were to the actual diamond values, the more that of aesthetic preference became. These findings highlight the potential for quantifying the aesthetic preference of diamond videos.

Bathing has various beneficial effects, including immune function strengthening, muscle fatigue recovery, and sweating function recovery. Furthermore, full-body bathing exerts a particularly significant thermal effect. In recent years, bathtubs equipped with a circulating bath water system have been developed as a means of increasing this thermal effect. However, few studies have investigated the thermal effect of bathing while running hot water over the neck and shoulders using a circulating bath water system. Thus, this study examined the thermal effect of circulating bath water running onto the neck and shoulders, and compared the effects with those of plain hot water bathing. Core body temperature and sweat rate were significantly increased using the circulating bath water system compared with bathing in plain hot water. Our findings suggest that circulating bath water on the neck and shoulders provides a strong thermal effect.