|Jas Brooks, Alireza Bahremand, Pedro Lopes, Christy Spackman, Judith Amores Fernandez, Hsin-Ni Ho, Masahiko Inami, Simon Niedenthal, Sharing and Experiencing Hardware and Methods to Advance Smell, Taste, and Temperature Interfaces, 2023 CHI Conference on Human Factors in Computing Systems, 10.1145/3544549.3573828, 2023.04.
|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..
|Zheng Yee Tan, Cameron Mavericks Choo, Youneng Lin, Hsin-Ni Ho, Ryo Kitada, The Effect of Temperature on Tactile Softness Perception, IEEE Transactions on Haptics, 10.1109/toh.2022.3198115, 1-8, 2022.08.
|Jones, L.A, Ho, H.-N, Incorporating Thermal Feedback in Cutaneous Displays: Reconciling Temporal and Spatial Disparities, Proceedings of the 11th International Workshop on Haptic & Audio Interaction Design, 2022.08.
|Referral of Wetness Sensation among Fingers.
|Thermal-tactile Integration in Object Temperature Perception..
|Material recognition based on thermal cues: Mechanisms and applications..
|Yizhen Zhou, Hsin-Ni Ho, Junji Watanabe, Perceptual-Semantic Congruency Facilitates Semantic Discrimination of Thermal Qualities, FRONTIERS IN PSYCHOLOGY, 10.3389/fpsyg.2017.02113, 8, 2113, 2017.12, The ability to sense temperature is vital to our life. It signals the environmental condition, reflects the physiological conditions of our own body, and generates feelings of pleasantness or unpleasantness. Moreover, recent studies have demonstrated implicit associations between physical temperature and social/emotional concepts, suggesting the processing of temperature may even influence cognition. In this work, we examined the effect of physical warmth and coldness on semantic cognition. Participants performed speeded target categorization for thermal descriptors in the form of semantic words or illustrative figures representing the thermal qualities "warm" or "cold" while physical thermal stimulation was presented. We compared the average reaction time (RT) for the congruent and incongruent conditions managed by response key assignments. In the congruent condition, the response key for the symbol associated with warmth (coldness) was assigned to the hand with warm (cold) thermal stimulation, and in the incongruent condition the key assignment was reversed. Our results demonstrate that the average RT in the congruent condition was faster than in the incongruent one for both forms of thermal descriptors, suggesting that the experience of physical temperature facilitates the internal processing of the meaning of thermal quality..
|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..
|Hsin-Ni Ho, Influence of Object Material Properties and Geometry on Skin Temperature Responses During Contact, HAPTICS: PERCEPTION, DEVICES, CONTROL, AND APPLICATIONS, EUROHAPTICS 2016, PT I, 10.1007/978-3-319-42321-0_26, 9774, 281-290, 2016.09, When the hand makes contact with an object, the changes in skin temperature provide information about not only the object's material composition but also its geometry. Consider, for example, the temperature difference felt when touching an aluminum block and a piece of aluminum foil. To study the thermal cues associated with material properties and object thickness, we measured the changes in skin temperature elicited when touching objects with varying material properties and geometries, and compared them to the theoretical predictions obtained from two thermal models, of which one assumes the object having an infinite thickness and the other takes into consideration the actual object thickness. The comparison results indicate that the former model is effective in capturing the rapid temperature changes at the moment of contact and the latter model is better at predicting the total change in skin temperature at the end of contact. These findings provide a knowledge basis for the development of thermal displays for material simulation and automatic object identification systems that identify an object's material composition and thickness based on thermal feedback..
|Ho HN, Iwai D, Yoshikawa Y, Watanabe J, Nishida S, Impact of hand and object colors on object temperature perception., Temperature (Austin, Tex.), 10.1080/23328940.2015.1078926, 2, 3, 344-345, 2015.07.
|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, George H. Van Doorn, Takahiro Kawabe, Junji Watanabe, Charles Spence, Colour-Temperature Correspondences: When Reactions to Thermal Stimuli Are Influenced by Colour, PLOS ONE, 10.1371/journal.pone.0091854, 9, 3, e91854, 2014.03, In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented..
|Hsin-Ni Ho, Daisuke Iwai, Yuki Yoshikawa, Junji Watanabe, Shin'ya Nishida, Effects of color on perceived temperature, Perception, 2013.08.
|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..
|Thermal referral: A filling-in phenomenon that involves cross-modal processing of thermal and tactile stimuli.
|Hsin-Ni Ho, Junji Watanabe, Hideyuki Ando, Makio Kashino, Somatotopic or spatiotopic? Frame of reference for localizing thermal sensations under thermo-tactile interactions, ATTENTION PERCEPTION & PSYCHOPHYSICS, 10.3758/APP.72.6.1666, 72, 6, 1666-1675, 2010.08, The thermal sense is diffuse and incapable of providing precise spatial information. From a phenomenon known as thermal referral, we know that touch influences the localization of cold or warmth, leading to our perceiving illusory thermal sensations at a thermally neutral site. This study investigated the frame of reference for localizing thermal sensations under thermal referral in order to shed light on how thermal and tactile modalities coordinate to process localization information. One thermally neutral tactile stimulator and two cold (warm) stimulators were presented to different sets of three fingers of both hands. The location of the neutral tactile stimulator varied, and the strength of the referral was estimated from participants' performance in localizing the neutral tactile stimulator. By manipulating the somatotopic and spatiotopic distances between the stimulated sites, we found that the somatotopic distance-more specifically, the distance between and among the sites being defined in cortical topography-determines the strength of thermal referral. Our findings suggest that localization of thermal sensations under thermo-tactile interactions is processed with respect to the somatotopic frame of reference and that this cross-modal processing resides in early cortical areas whose organization conserves topographic information..
|Jessica Galie, Hsin-Ni Ho, Lynette A. Jones, Influence of Contact Conditions on Thermal Responses of the Hand, WORLD HAPTICS 2009: THIRD JOINT EUROHAPTICS CONFERENCE AND SYMPOSIUM ON HAPTIC INTERFACES FOR VIRTUAL ENVIRONMENT AND TELEOPERATOR SYSTEMS, PROCEEDINGS, 10.1109/WHC.2009.4810902, 587-+, 2009.10, A series of experiments was conducted to evaluate how contact pressure and surface roughness influence the heat flux conducted out of the skin or object during contact. Changes in skin temperature assist in identifying objects held in the hand. In the first experiment an infrared thermal imaging system was used to measure skin temperature and contact area as participants generated forces ranging from 0.1 to 6 N with their index finger. The results showed that skin temperature decreased by an average of 5.5 degrees C across the range of forces studied and that the changes were greatest between 0.25-0.35 N and from 4-6 N. The second and third experiments examined the effect of the surface roughness of an object on skin temperature and on the perceived coldness of the object. A set of six copper blocks was machined to create a range of surface profiles. There was a slight decrease in skin temperature as the surface roughness of the object increased, contrary to theoretical predictions. Although small, these changes were perceptible as participants consistently chose the rougher of two stimuli when asked to select the cooler stimulus. These results indicate that contact pressure and surface roughness influence the change in skin temperature during contact and that they can have a perceptible influence on the perceived properties of objects held in the hand. Thermal models need to account for these effects if realistic feedback is to be presented in a thermal display..
|Hsin-Ni Ho, Lynette A. Jones, Modeling the thermal responses of the skin surface during hand-object interactions, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, 10.1115/1.2899574, 130, 2, 021005, 2008.04, The objective of this research is to. analyze and model the decreases in skin temperature when the hand makes contact with an object at room temperature so that thermal feedback can be incorporated into haptic displays. A thermal model is proposed that predicts the thermal responses of the skin and object surface as well as the heat flux exchanged during hand-object surface as well as the heat flux exchanged predictions of temperature changes to those experimentally measured using an infrared thermal measurement system. The thermal measurement system was designed to overcome the limitations imposed by contact thermal sensors, and was able to measure skin temperature during contact, together with the contact area and contact force. The experimental results indicated that over the pressure range of 0.73-10.98 kPa, changes in skin temperature were well localized to the contact area and were affected by contact pressure. The pressure in turn influenced both thermal contact resistance and blood flow. Over the range of contact forces typically used in manual exploration, blood perfusion and metabolic heat generation do not appear to have a significant effect on the skin's thermal responses. The theoretical predictions and the measured data were consistent in characterizing the time course and amplitude of the skin temperature change during contact with differences typically being less than 1 degrees C between the two for pressures greater than 4 kPa. These findings indicate that the proposed thermal model is able to characterize and predict the skin temperature responses during hand-object interactions and could be used in a thermal display that simulates the properties of different materials..
|Lynette A. Jones, Hsin-Ni Ho, Warm or Cool, Large or Small? The Challenge of Thermal Displays, IEEE TRANSACTIONS ON HAPTICS, 10.1109/ToH.2008.2, 1, 1, 53-70, 2008.01, Thermal displays have been developed to present thermal cues to the hand to facilitate object recognition in virtual environments or in teleoperated robotic systems. This review focuses on this application domain of thermal displays and considers the models developed to simulate the thermal interaction between an object and the hand as they make contact. An overview of thermal perception and the mechanisms underlying the processing of thermal information is provided to give a framework for analyzing the design of thermal displays. The models developed to simulate thermal feedback are examined together with a description of the implementation of these models in thermal displays. The domains in which thermal displays have been used are described; this includes the simulation of material properties, the recreation of large-scale thermal effects in virtual environments, the encoding of abstract concepts, and the use of thermal feedback in interactive art. The review concludes by considering the advantages and challenges associated with using thermal displays in these diverse areas..
|Hsin-Ni Ho, Lynette A. Jones, Development and Evaluation of a Thermal Display for Material Identification and Discrimination, ACM TRANSACTIONS ON APPLIED PERCEPTION, 10.1145/1265957.1265962, 4, 2, 13, 2007.07, The objective of this study was to develop and evaluate a thermal display that assists in object identification in virtual environments by simulating the thermal cues associated with making contact with materials with different thermal properties. The thermal display was developed based on a semi-infinite body model. Three experiments were conducted to evaluate the performance of the display. The first experiment compared the ability of subjects' to identify various materials, which were presented physically or simulated with the thermal display. The second experiment examined the capacity of subjects to discriminate between a real and simulated material based on thermal cues. In the third experiment, the changes in skin temperature that occurred when making contact with real and simulated materials were measured to evaluate how these compare to theoretical predictions. The results indicated that there was no significant difference in material identification and discrimination when subjects were presented with real or simulated materials. The changes in skin temperature were comparable for real and simulated materials and were related to the contact coefficient of the material palpated, consistent with the semi-infinite body model. These findings suggest that a thermal display is capable of facilitating object recognition when visual cues are limited..
|Hsin-Ni Ho, Lynette A. Jones, Infrared thermal measurement system for evaluating model-based thermal displays, WORLD HAPTICS 2007: SECOND JOINT EUROHAPTICS CONFERENCE AND SYMPOSIUM ON HAPTIC INTERFACES FOR VIRTUAL ENVIRONMENT AND TELEOPERATOR SYSTEMS, PROCEEDINGS, 10.1109/WHC.2007.76, 157-+, 2007.04, A thermal measurement system was designed and fabricated to assist in the validation of a thermal model in characterizing skin temperature during hand-object interactions. An infrared measurement system was used to overcome the limitations imposed by contact thermal sensors. It is able to measure the temperature distribution across the fingerpad during contact, together with contact area and contact force. The performance of this system was evaluated with calibration tests and the results indicated that this system is capable of providing accurate temperature measurements. With this system,. analyses of the changes in skin temperature as a function of contact pressure were conducted These analyses permitted the validation of a thermal model proposed in a previous study and the results indicate that the thermal model is able to predict skin temperature during contact. The model can simulate the properties of different materials in a thermal display..
|Hsin-Ni Ho, Lynette A. Jones, Thermal model for hand-object interactions, SYMPOSIUM ON HAPTICS INTERFACES FOR VIRTUAL ENVIRONMENT AND TELEOPERATOR SYSTEMS 2006, PROCEEDINGS, 10.1109/VR.2006.132, 461-467, 2006.06, A thermal model is proposed that predicts the temperature responses of the skin and material surface during hand-object interactions as well as the heat flux exchanged when the fingerpad makes contact with an object. The surface features of the fingerpad were measured in order to estimate the thermal contact resistance which is included in the model. A simulation based on the model was performed to calculate the thermal responses of the fingerpad as it made contact with a range of materials with varying thermal properties. A thermal measurement system based on an infrared camera has been designed and fabricated to overcome the limitations imposed by the contact thermal sensors. This system will be used to evaluate the validity of the model in predicting the changes in skin temperature during contact..
|HN Ho, LA Jones, Contribution of thermal cues to material discrimination and localization, PERCEPTION & PSYCHOPHYSICS, 68, 1, 118-128, 2006.01, The objective of these two experiments was to determine the role of thermal cues in material discrimination and localization, using materials that spanned a range of thermal properties. In the first experiment, the subjects were required to select the cooler of two materials presented to the index fingers. In the second, the finger that was in contact with a material that was different from that presented to the other two fingers on the same hand had to be identified. The results indicated that the subjects were able to discriminate between materials, using thermal cues, when the differences in their thermal properties were large. The changes in skin temperature when the fingers were touching the materials were, however, smaller than those predicted by the theoretical model. The ability to localize the thermal changes when three fingers on the same hand were stimulated was poor and depended on both the thermal properties of the target and the distractor materials..