||Takuya Jodai, Masahiko Terao, Lynette A. Jones, Hsin-Ni Ho, Determination of the Thermal-tactile Simultaneity Window for Multisensory Cutaneous Displays, World Haptics 2023, 2023.07.
||Yusuke Ujitoko, Takumi Yokosaka, Yuki Ban, Hsin-Ni Ho, Tracking changes in touch desire and touch avoidance before and after the COVID-19 outbreak, Frontiers in Psychology, 10.3389/fpsyg.2022.1016909, 13, 1016909-1016909, 2022.12, Touch is essential for survival, social bonding, and overall health. However, the COVID-19 pandemic calls for an abrupt withdrawal from physical contact, and the prolonged lockdown has left many people in solitude without touch for months. This unprecedented dissociation from touch has cast a shadow on people's mental and physical well-being. Here we approached the issue by examining COVID-19's impact on people's touch attitudes. We analyzed people's desire and avoidance for animate and inanimate targets based on large-scale Japanese Twitter posts over an 8-year span. We analyzed the impact of the COVID-19 outbreak with the difference-in-differences estimation method, which can estimate the impact while accounting for other changes over time such as seasonality or long-term effects. As a result, we found that people's desire for touching the human body and pet animals increased significantly after the COVID-19 outbreak and remained high afterward. In contrast, the avoidance of touching everyday objects (e.g., doorknobs and money) increased immediately after the outbreak but gradually returned to the pre-COVID-19 levels. Our findings manifest the impact of COVID-19 on human touch behavior. Most importantly, they highlight the sign of “skin hunger,” a public health crisis due to social distancing, and call attention to the trend that people are becoming less aware of infection control as COVID-19 persists..
||Material recognition based on thermal cues: Mechanisms and applications..
||Hsin-Ni Ho, Katsunari Sato, Scinob Kuroki, Junji Watanabe, Takashi Maeno, Shin'ya Nishida, Physical-Perceptual Correspondence for Dynamic Thermal Stimulation, IEEE TRANSACTIONS ON HAPTICS, 10.1109/TOH.2016.2583424, 10, 1, 84-93, 2017.01, Thermal displays have been applied in various haptic applications, from material simulation to interpersonal communication; however, there is insufficient knowledge about the temporal processing in human thermal sense to provide a knowledge basis for thermal display design. In this study, we investigated the physical-perceptual correspondence for dynamic thermal stimulation to shed a light on the temporal processing of human thermal sense. In the experiments, participants reported subjective timings of the temperature onset and temperature peak of continuous temperature changes applied to the thenar eminence. We found that the physical-perceptual correspondence was not consistent for warm and cold stimulations. For warm stimulation, the subjective experience always came after the corresponding physical event. On the other hand, for cold stimulation, while the subjective onset always lagged the physical onset, the subjective temperature peak preceded the physical temperature peak. We analyzed these results in the framework of linear systems theory. The results suggest that the senses of warmth and cold have distinct temporal filtering properties, with the sense of cold being more transient than the sense of warmth. These findings advance our knowledge regarding temporal processing in human thermal sense and serve as a basis for thermal display design..
||Penny Bergman, Hsin-Ni Ho, Ai Koizumi, Ana Tajadura-Jimenez, Norimichi Kitagawa, The pleasant heat? Evidence for thermal-emotional implicit associations occurring with semantic and physical thermal stimulation, COGNITIVE NEUROSCIENCE, 10.1080/17588928.2014.988132, 6, 1, 24-30, 2015.01, The association between thermal and emotional experiences in interpersonal relations is intuitively apparent and has been confirmed by previous studies. However, research has not yet elucidated whether such an association is grounded in mental processes occurring at an intrapersonal (internal) level. In two experiments we examined whether the thermal-emotional associations can be observed at an intrapersonal level. We looked at the speed and accuracy of stimuli categorization. Experiment 1 examined the implicit semantic association between temperature (warm versus cold) and emotional valence (positive versus negative). Experiment 2 examined the association between experience of physical temperature and emotional valence. In both experiments warm-positive/cold-negative associations were demonstrated. These results suggest a conceptual and perceptual mapping in the mental representation of emotion and temperature, which occurs at an intrapersonal level, and which might serve as the ground to the interpersonal thermal-emotional interactions..
||Hsin-Ni Ho, Daisuke Iwai, Yuki Yoshikawa, Junji Watanabe, Shin'ya Nishida, Combining colour and temperature: A blue object is more likely to be judged as warm than a red object, SCIENTIFIC REPORTS, 10.1038/srep05527, 4, 5527, 2014.07, It is commonly believed that reddish colour induces warm feelings while bluish colour induces cold feelings. We, however, demonstrate an opposite effect when the temperature information is acquired by direct touch. Experiment 1 found that a red object, relative to a blue object, raises the lowest temperature required for an object to feel warm, indicating that a blue object is more likely to be judged as warm than a red object of the same physical temperature. Experiment 2 showed that hand colour also affects temperature judgment, with the direction of the effect opposite to object colours. This study provides the first demonstration that colour can modulate temperature judgments when the temperature information is acquired by direct touch. The effects apparently oppose the common conception of red-hot/blue-cold association. We interpret this phenomenon in terms of ''Anti-Bayesian'' integration, which suggests that the brain integrates direct temperature input with prior expectations about temperature relationship between object and hand in a way that emphasizes the contrast between the two..
||Hsin-Ni Ho, Junji Watanabe, Hideyuki Ando, Makio Kashino, Mechanisms Underlying Referral of Thermal Sensations to Sites of Tactile Stimulation, JOURNAL OF NEUROSCIENCE, 10.1523/JNEUROSCI.2640-10.2011, 31, 1, 208-213, 2011.01, When three stimulators are simultaneously touched with the middle three fingers of one hand but only the outer two stimulators are cooled or heated, the central (neutral) stimulator is also perceived to be cold or warm. This phenomenon is known as thermal referral and it shares phenomenological similarities with filling-in, in which the discontinuity in the signals of interest can be compensated perceptually on the basis of the spatially adjacent context. Although the mechanisms underlying filling-in have been well substantiated, those underlying thermal referral are still poorly understood. In the present study, we examined the intensity perception of the sensation resulting from thermal referral with human participants. We found that the sensation was uniform among the three fingers, but its apparent intensity was always lower than the physical intensity applied to the outer two fingers. These results indicate that the thermal uniformity perceived under thermal referral is not created by the brain's interpolating the thermal changes applied to the outer two fingers, as one would expect for those induced by typical filling-in. Instead, the thermal changes applied to the outer two fingers are summated and redistributed to all the fingers in contact. Our findings suggest that thermal referral is mediated by two separate processes. One determines the apparent intensity from the physical intensity and the areal extent of the thermal stimulation; the other determines the localization of the resulting sensation from the apparent sites of tactile stimulation..