Touch Behavior Research Articles

Haptics in social interaction with agents and avatars in virtual reality: a systematic review

Incorporating the sense of touch through haptics in virtual spaces enables people to communicate emotions and engage in more naturalistic and meaningful social interactions. Advances in haptics and virtual reality technologies and applications have been essential to support researchers in the exploration of mediated social touch in virtual environments. The aim of this work is to review the last decade of research on haptics and virtual reality technologies investigating social touch behavior between human avatars as well as between humans and non-human virtual agents. Our systematic review organizes the variety of the conducted research in three dimensions: the context against which mediated social touch is studied, the types of haptics and virtual reality technology used, and empirical studies including data collected and outcome measures. We discuss the results of the analysis of the three dimensions and present implications for future research. We pinpoint the importance of considering in-the-wild studies and emerging issues on social virtual reality; understanding human touch perception for people with different physical and cognitive abilities, and; creating development tools to broaden the exploration of advanced technological setups.

Stroking and Leaning: The Give and Take of Social Touch Between Humans and Their Pets

ABSTRACT Affectionate interpersonal touch serves important social and affective functions. In this study, we asked whether the same holds for the physical contact between pet owners and their pets. An international sample of pet owners (n = 443) rated the typicality of different human and pet touch behaviors. They then provided body contact maps for typical behaviors and reported the duration of behaviors, probability across different situations, and associated affect. Human–pet touch was characterized by a range of tactile behaviors, especially stroking by owners and leaning by pets. Touching took substantial time (∼42 min/day) and occurred most often when owners were resting, after separation, and during joint activities with the pet. Some forms of touch entailed physically intimate contact and were followed by positive affect. Although the touch behaviors showed some differences, overall, owner touching and pet touching were similar and reciprocal. Together, our data identify parallels between interpersonal and human–pet touch and establish human–pet interactions as an important source of affectionate touch experiences.

Measuring differences in social touch: Development and validation of the short Touch Experiences and Attitudes Questionnaire (TEAQ-s)

Interpersonal touch is an essential part of human social life, impacting emotional and physical well-being. Variations in touch behavior and perception can be assessed by the Touch Experiences and Attitudes Questionnaire (TEAQ). Although comprehensive, the TEAQ appears lengthy with 57 items, limiting its usability for large surveys. Therefore, we developed a refined and shortened version of 16 items, tested in Germany and France. This manuscript presents three studies. In the first, we created the TEAQ-s (n = 313). In the second and third, we validated the TEAQ-s in German (n = 383) and French (n = 327), respectively. The resulting TEAQ-s showed strong reliability (Cronbach's alpha: 0.86 to 0.87; test-retest correlation: r = 0.85) and validity consistent with the original version. Analyses also revealed that being in a relationship, relationship satisfaction, mental health, and body appreciation were positively related to touch experiences and attitudes. A four-factor structure (4 items per scale) was confirmed through factor analysis. Final subscales are attitude to friendly touch, current intimate touch, childhood touch, and attitude to intimate touch. We hope that the TEAQ-s serves as a valuable tool for researchers in the field of touch and beyond, offering well-founded items in an efficient format.

In-vivo toxicological study of cysteamine modified carbon dots derived from Ruellia simplex on fruit fly for potential bioimaging

Modern medicine must shift its paradigm from conventional treatment strategies to theranostics to meet individuals' needs. Carbon dots, as a class of fluorescent materials, provide biocompatible and multifunctional solutions for a wide range of applications including clinical sensing, imaging, and drug delivery. Various studies have focused on their synthesis, photophysical properties, and innoxious nature but their potential biomedical applications for the in-vivo toxicity are yet limited. In this work, previously synthesized C-Dots (CDs) were utilized to determine their effect on the development of Drosophila melanogaster. Simultaneously, the genotoxic potential of CDs was evaluated on specific larval cell types that play important roles in immunological defence as well as growth and development. The gut organ toxicity of both CDs was studied using DAPI and DCFH-DA dyes wherein RS-CDs didn't show significant toxicity to the concentration 500 μg/mL whereas RS-Cys-CDs showed nuclear fragmentation and modest ROS (reactive oxygen species) production. Subsequently, trypan-blue assay, larvae crawling assay, touch sensitivity, adult phenotype, and survivability assay were performed. The trypan-blue assay shows the non-toxic nature of both CDs even at the concentration of 500 μg/mL. The high concentrations of RS-Cys-CD (500 μg/mL) were further associated with the alteration in touch behaviour and decrease in pupa hatching. In-vivo and ex-vivo fluorescence assessment of both the CDs exhibit bright fluorescence in green and red channels upon excitation at 485 and 577 nm respectively. The prominent imaging results from RS-Cys-CDs highlight the positive impact of surface modification.

Phthalates on indoor surfaces and associated exposure via surface touch behavior: Observation in university dormitories and its implications

Phthalates are typical emerging indoor pollutants and ubiquitously distributed in the indoor air, settled dust and on surfaces. Phthalates have the potential to be transported by human hands through surface touch behaviors. Although the contribution of subsequent exposure via hand-to-mouth contact in real indoor environments has not been thoroughly characterized, it is an important factor to consider. In this study, six commonly-used phthalates (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), butyl benzyl phthalate (BBzP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DOP)) were measured in surface wipes, air and dust samples collected from university dormitories. Video-cameras were used to monitor occupants’ real surface touch behaviors. Primary surfaces being touched included desks, cellphones, keyboards and computer mice, with averaged touch frequencies ranging from 10.4 h−1 to 25.4 h−1. Phthalate levels on computer mice were the highest, with DEHP being present as the most predominant compound (mean: 2621 μg/m2). Exposures via inhalation, dust ingestion, dermal absorption and hand-to-mouth contact were further estimated using Monte-Carlo simulations. The results suggest that the exposure resulting from surface touching and subsequent hand-mouthing could contribute 35 %–55 % to total exposure for targeted phthalates, which were generally higher than intakes via dust ingestion. This study provides a better understanding of phthalate transfer through surface touch behavior, and highlights the significance of hand-to-mouth contact exposure in indoor environments.

Affective Touch in Adult Relationships in the Light of Psychological Research. Excerpts

Touch is one of our love languages. In addition to the fact that we use touch to express love, I explore its role and significance in our lives. In the present work, drawing on the growing literature, I focus on affective touch, including received touch, in the context of adult romantic relationships. After defining affective touch, I discuss its beneficial effects. Based on research results, I show that affective touch in the context of relationships is related to physical, mental, and relational health and well-being. But not always and not for everyone. Thus, I cover some of the factors affecting touch behaviour and attitude. I discuss separately the phenomenon where, still within the couple relationship and remaining in the field of affective touch, the touch itself becomes a source of stress. We have all experienced the effects of measures taken to control the epidemic, such as social distancing and avoidance of touch. In this context, I present some of the results of our research on COVID. All of these are excerpts. I hope they will inspire others to further research. Keywords: affective touch, adult partnership, well-being

Exploration of a method for insight into accessibility design flaws based on touch dynamics

The widespread use of smartphones implies that intelligent systems must address the negative emotions experienced by a diverse user group when encountering usability difficulties. Therefore, exploring the relationship between users’ emotions and operational behaviors is crucial for further enhancing the accessibility of intelligent systems. Touch dynamics, as a method of dynamic touch data monitoring, has already provided many models for emotion recognition, which are beneficial in gaining insight into users’ accessibility needs for smartphones and exploring intelligent solutions to design issues. This paper validates this aspect through interviews and experimental studies. The study first conducted an open-ended interview, and then used a touch behavior experiment with emotional labels and a questionnaire to validate the association between accessibility design flaws in intelligent systems and user emotions. The interview results show that middle-aged and older smartphone users have difficulty activating accessibility tools independently. Consequently, this paper establishes a dataset for emotion classification based on touch gesture data, which is used to gain insight into implicit difficulties in the interaction process through negative emotions. From a touch experiment and questionnaire survey of 57 sample users, there is approximately a 78.57% match between the accessibility needs of intelligent systems and users’ negative emotions, with interaction fluency and interface cognition being the main reasons for this phenomenon. Therefore, touch dynamics, as a non-invasive method of emotion recognition, can use negative emotional feedback to gain insights into user needs that are difficult to detect by other methods. This has application value for enhancing users’ emotional experience and promoting a transformation in interaction design thinking.

ONE3A: one-against-all authentication model for smartphone using GAN network and optimization techniques.

This study focuses on addressing computational limits in smartphones by proposing an efficient authentication model that enables implicit authentication without requiring additional hardware and incurring less computational cost. The research explores various wrapper feature selection strategies and classifiers to enhance authentication accuracy while considering smartphone limitations such as hardware constraints, battery life, and memory size. However, the available dataset is small; thus, it cannot support a general conclusion. In this article, a novel implicit authentication model for smartphone users is proposed to address the one-against-all classification problem in smartphone authentication. This model depends on the integration of the conditional tabular generative adversarial network (CTGAN) to generate synthetic data to address the imbalanced dataset and a new proposed feature selection technique based on the Whale Optimization Algorithm (WOA). The model was evaluated using a public dataset (RHU touch mobile keystroke dataset), and the results showed that the WOA with the random forest (RF) classifier achieved the best reduction rate compared to the Harris Hawks Optimization (HHO) algorithm. Additionally, its classification accuracy was found to be the best in mobile user authentication from their touch behavior data. WOA-RF achieved an average accuracy of 99.62±0.40% with a reduction rate averaging 87.85% across ten users, demonstrating its effectiveness in smartphone authentication.

Face reality - consider face touching behaviour on subsequent DNA analysis

ABSTRACT Face touching is a common habit that can have implications on the outcome of criminal investigations. When conducting activity level assessments, it is important to be aware of any factors that may impact the type of profile obtained from the sample of interest. This may include the number, duration, location, and manner of contacts that a person makes with themselves. In this study we have recorded the contacts made by different individuals, of their hands with their face, over a 1 hr period, while working within an office. All participants were observed to regularly touch their face. Swabs of the face of some participants were subsequently collected for DNA profiling. The individuals sampled were found to be the sole or majority contributor to the profiles generated.

Where and how often do people touch train interiors? An investigation during the pandemic

The coronavirus disease-2019 pandemic highlighted infection and hygiene as risks in dense public spaces, including public transport vehicles. This study investigated passenger touching behaviour within metro vehicles to understand the fomite exposure of passengers. Using in-vehicle CCTV on three lines of the London Underground, this paper investigated the number of touches on different types of train interiors and investigated their relationship with passenger density and movement. In total, 1818 station sections and 16 891 passengers were observed cumulatively from May to December 2021. The results showed that on average for each type of interiors on Victoria and Jubilee lines, there were between 0.07 and 0.57 touches per passenger movement (i.e. boarding or alighting) for deep tube lines, whereas District line that uses larger carriages showed a different tendency. The results also suggested that for deep tube lines, the number of touches per person increased beyond a density of ∼1.5 standing passengers/m2 possibly because passengers may touch interiors more in order not to bump into other passengers. These findings can be used in infection risk modelling and can inform mitigation of infection risk of future pandemics.

Perceptions and behavioral traits of mask usage during covid-19 pandemic–a cross sectional study from Kerala

Background: The first reported case of COVID in all of India was in Thrissur, Kerala. Kerala was one among the states which had high recovery rate, low death rate and slow progression which was recognized internationally in managing and controlling the COVID-19 pandemic. For efficient control of transmission of COVID 19, mask wearing was considered as primary and popular measure. Wearing mask everytime can cause discomfort and prolonged mask usage can lead to many health impacts. Mask wearing can be made comfortable and convenient, if the discomforts and health impacts of wearing mask are worked on in future. Objective: To study perceptions and behavioural traits related to mask usage in general population of Kerala, India. Methods: An online cross sectional study was conducted in Kerala among 291 adults aged 20 to 60 years with a validated questionnaire. Data was analysed with Pearson’s Chi square and Odds ratio. Results: Majority of the participants were self-motivated, though 90% of participants reported mild discomforts, yet more than 80% were inclined to proper mask wearing practice. Among the participants, 77% washed and reused masks, more than 49% changed their face touching behavior, 67 % were inspired by family and friends in wearing mask. Older participants (greater than 40 years) had higher knowledge level of mask use (98%) and wearing masks outdoors (92.8%), lesser preference for N95 mask and double mask compared to younger participants. Conclusion: Study reinforces hypothesis of mask use efficacy in controlling and reducing pandemic spread. Community perceptions and behavioural traits study can enhance planning and implementation of public health programs.

COVID-19 and Social Distancing: A Cross-Cultural Study of Interpersonal Distance Preferences and Touch Behaviors Before and During the Pandemic

The COVID-19 pandemic has led to the introduction of unprecedented safety measures, one of them being physical distancing recommendations. Here, we assessed whether the pandemic has led to long-term effects on two important physical distancing aspects, namely interpersonal distance preferences and interpersonal touch behaviors. We analyzed nearly 14,000 individual cases from two large, cross-cultural surveys – the first conducted 2 years prior to the pandemic and the second during a relatively stable period of a decreased infection rate in May-June 2021. Preferred interpersonal distances increased by 54% globally during the COVID-19 pandemic. This increase was observable across all types of relationships, all countries, and was more pronounced in individuals with higher self-reported vulnerability to diseases. Unexpectedly, participants reported a higher incidence of interpersonal touch behaviors during than before the pandemic. We discuss our results in the context of prosocial and self-protection motivations that potentially promote different social behaviors.

Examining the Relationship Between Touch and Visual Perception: Pareidolia Perception in the Social Brain

Purpose: Human perception is a complex system based on the interaction of different modalities. However, it is unclear how adults’ perception of social touch influences their social dimension of visual perception. The aim of this study is to investigate the relationship between social touch perception and visual perception in the social brain. 
 Materials and methods: The survey study recruited 802 healthy participants. Thus, a self-report survey that included the Social Touch Questionnaire consisting of three factors and the pareidolia test were used. Pearson’s Correlation and one- way ANOVA was performed for analysis. 
 Result: We display a statistically significant negative correlation between face reaction time, personal social touch factor, and liking personal social touch factor. An adverse important relationship emerged between pareidolia reaction time, liking of personal social touch, and social touch behavior factors. 
 Conclusion: According to our results, multimodal perception necessitates the simultaneous activation of multiple heteromodal associations in the social brain. Our findings can be interpreted as an interaction between the Dorsal and Ventral Attention Networks and the Social Brain Network.

Fomite Transmission in Airports Based on Real Human Touch Behaviors

The public areas of airports are often bustling, raising the risk of infectious diseases spreading through fomites. We recorded 21.3 h of video at three airports, focusing on nine common areas (e.g., boarding and check-in areas) where people touch surfaces. We analyzed 25,925 touches to create a model for how microbes spread from surfaces to humans through touch. The airport mask-wearing rate is high (96.1% in non-restaurant areas), but it is lower (22%) in restaurants. Passengers touch their mucous membranes more often (10.3 times/hour) in restaurants compared to other areas (1.6 times/hour on average). Wearing a mask can significantly reduce the risk of obtaining a virus through direct contact with hands and mucous membranes. If everyone in non-restaurant areas wore masks, the viral intake fraction could be reduced by up to 97.4% compared to not wearing masks. People touch public surfaces the most in self-service check-in areas, at a rate of 473.5 times per hour. Disinfecting public surfaces or hands twice per hour could reduce the viral intake fraction in each area by 27.7% or 15.4%, respectively. The findings of this study provide valuable data support and a scientific foundation for implementing interventions aimed at mitigating fomite transmission within airport settings.

An Emotional-Aware Mobile Terminal Accessibility-Assisted Recommendation System for the Elderly Based on Haptic Recognition

For the purpose of improving the user experience of mobile smart terminals for the elderly, accessibility tools have become an indispensable component of intelligent system frameworks to meet the varying needs of senior citizens for assistance. Nonetheless, the complexity of accessibility assistive tools complicates the lives of some elderly with a lack of cognitive experience to use these tools independently. Our purpose is to study the relationship between the accessibility design elements of smartphones, the emotions, and touch behaviors of elderly users, and to optimize the accessibility design methods of mobile smart terminals. First, we obtained the four interface elements with the most influence on users through a Semantic Differential evaluation involving 50 participants. Second, in a touch event collection experiment, 20 participants’ touch data was collected, and an SVM-based correlation model between interface elements, user emotions, and touch behaviors was established. Third, the prototype of the assistive recommender was iterated employing the combination of the correlation model and Genetic Algorithms. Ultimately, the effectiveness of the six touch media recommendations was compared through usability testing. The experimental results indicates that: (1) Emotion-aware accessibility assistive recommendation systems based on haptic recognition can enhance the elderly’s ability to access information through mobile terminals. (2) Middle-aged and elderly users have a more robust negative emotion reflection for dragging and swiping on touch screens. (3) Negative emotions of elderly users can assist identify design defects of accessibility tools. Our research work distilled a set of design suggestions for digital accessibility improvement, thereby enhancing the usability and inclusiveness of assistive tools in diverse contexts, and reducing the psychological pressure caused by unfamiliar interfaces. This study supplies a reference for improving the emotional experience of elderly people employing mobile terminals and extending the approach to accessible design.

VibPath

Technical advances in the smart device market have fixated smartphones at the heart of our lives, warranting an ever more secure means of authentication. Although most smartphones have adopted biometrics-based authentication, after a couple of failed attempts, most users are given the option to quickly bypass the system with passcodes. To add a layer of security, two-factor authentication (2FA) has been implemented but has proven to be vulnerable to various attacks. In this paper, we introduce VibPath, a simultaneous 2FA scheme that can understand the user's hand neuromuscular system through touch behavior. VibPath captures the individual's vibration path responses between the hand and the wrist with the attention-based encoder-decoder network, authenticating the genuine users from the imposters unobtrusively. In a user study with 30 participants, VibPath achieved an average performance of 0.98 accuracy, 0.99 precision, 0.98 recall, 0.98 f1-score for user verification, and 94.3% accuracy for user identification across five passcodes. Furthermore, we also conducted several extensive studies, including in-the-wile, permanence, vulnerability, usability, and system overhead studies, to assess the practicability and viability of the VibPath from multiple aspects.

Pursuing Safety in Social Connection: A Flexibly Fluid Perspective on Risk Regulation in Relationships.

People are fundamentally motivated to be included in social connections that feel safe, connections where they are consistently cared for and protected, not hurt or exploited. Romantic relationships have long played a crucial role in satisfying this fundamental need. This article reconceptualizes the risk-regulation model to argue that people draw on experiences from inside and outside their romantic relationships to satisfy their fundamental need to feel safe depending on others. We first review the direct relational cues (i.e., a partner's affectionate touch, responsive versus unresponsive behavior, and relative power) and indirect cues (i.e., bodily sensations, collective value in the eyes of others, and living conditions) that signal the current safety of social connection and motivate people to connect to others or protect themselves against them. We then review how people's chronic capacity to trust in others controls their sensitivity and reactivity to the safety cues. The article concludes with future research directions.

An intensive longitudinal investigation of maternal and infant touching patterns across context and throughout the first 9-months of life.

Touch is a central component of mothers' and infants' everyday interactions and the formation of a healthy mother-infant relationship. Twelve mothers and their full-term infants from the Midwest, USA participated in the present study, which examined the quality and quantity of their touching behaviors longitudinally at 1-, 3-, 5-, 7-, and 9-months postpartum and within two normative interaction contexts (face-to-face, floor play). Findings revealed that mothers' and infants' individual touch patterns, varied according to context, infant age (time), and the specific type of touch examined. At 1-month postpartum, dyads coordinated their touch via behavioral matching and were especially reliant on rudimentary types of touch with soothing and regulatory properties (static/motionless touch, stroking). As infants aged to 9-months, dyads transitioned to a more complex form of tactile synchrony characterized by the parallel use of complementary types of touch (grasp, poke, pull). This evolution of tactile synchrony may reflect infants' growing behavioral repertoire and increased capacity to use more refined forms of touch. To our knowledge, this study was the first of its kind, uniquely contributing to the scant knowledge about the development of mother-infant touch and synchrony and offering direct implications for early care practices and infant health and well-being.

Aβ-CT Affective Touch: Touch Pleasantness Ratings for Gentle Stroking and Deep Pressure Exhibit Dependence on A-Fibers.

Gentle stroking of the skin is a common social touch behavior with positive affective consequences. A preference for slow versus fast stroking of hairy skin has been closely linked to the firing of unmyelinated C-tactile (CT) somatosensory afferents. Because the firing of CT afferents strongly correlates with touch pleasantness, the CT pathway has been considered a social-affective sensory pathway. Recently, ablation of the spinothalamic pathway- thought to convey all C-fiber sensations- in patients with cancer pain impaired pain, temperature, and itch, but not ratings of pleasant touch. This suggested integration of afferent A and CT fiber input in the spinal cord, or mechanoreceptive A-fiber contributions to computations of touch pleasantness in the brain. However, contribution of mechanoreceptive A-fibers to touch pleasantness, in humans without pain, remains unknown. In the current, single-blinded study, we performed two types of peripheral nerve blocks in healthy adults to temporarily eliminate the contribution of A-fibers to touch perception. Our findings show that when mechanoreceptive A-fiber function is greatly diminished, the perceived intensity and pleasantness of both gentle stroking and deep pressure are nearly abolished. These findings demonstrate that explicit perception of the pleasantness of CT-targeted brushing and pressure both critically depend on afferent A-fibers.

Love and affectionate touch toward romantic partners all over the world

Touch is the primary way people communicate intimacy in romantic relationships, and affectionate touch behaviors such as stroking, hugging and kissing are universally observed in partnerships all over the world. Here, we explored the association of love and affectionate touch behaviors in romantic partnerships in two studies comprising 7880 participants. In the first study, we used a cross-cultural survey conducted in 37 countries to test whether love was universally associated with affectionate touch behaviors. In the second study, using a more fine-tuned touch behavior scale, we tested whether the frequency of affectionate touch behaviors was related to love in romantic partnerships. As hypothesized, love was significantly and positively associated with affectionate touch behaviors in both studies and this result was replicated regardless of the inclusion of potentially relevant factors as controls. Altogether, our data strongly suggest that affectionate touch is a relatively stable characteristic of human romantic relationships that is robustly and reliably related to the degree of reported love between partners.