Primary somatosensory cortical processing in tactile communication.

Touch is an essential form of non-verbal communication. While language and its neural basis are widely studied, tactile communication is less well understood. We used fMRI and multivariate pattern analyses in pairs of emotionally close adults to examine the neural basis of human-to-human tactile communication. In each pair, a participant was designated either as sender or as receiver. The sender was instructed to communicate specific messages by touching only the arm of the receiver, who was inside the scanner. The receiver then identified the message based on the touch expression alone. We designed two multivariate decoder algorithms-one based on the sender's intent (sender-decoder), and another based on the receiver's response (receiver-decoder). We identified several brain areas that significantly predicted behavioural accuracy of the receiver. Regarding our a priori region of interest, the receiver's primary somatosensory cortex (S1), both decoders were able to accurately differentiate the messages based on neural activity patterns here. The receiver-decoder, which relied on the receivers' interpretations of the touch expressions, outperformed the sender-decoder, which relied on the sender's intent. Our results identified a network of brain areas involved in human-to-human tactile communication and supported the notion of non-sensory factors being represented in S1. This article is part of the theme issue 'Sensing and feeling: an integrative approach to sensory processing and emotional experience'.

New Strategies in the Treatment of Plasmodium berghei Based on Nanoparticles: A Systematic Review.

BACKGROUND: Drug resistance is a current issue affecting parasites caused by Plasmodium. Therefore, researchers have expanded their studies on nanoparticles to find new and effective drugs that can treat drug-resistant strains. The present study systematically investigates the effect of different nanoparticles, including metal, polymer, and lipid nanoparticles, on Plasmodium berghei. METHODS: In this study, English-language online literature was obtained from the databases Science Direct, PubMed, Scopus, Ovid, and Cochrane to conduct a systematic review. In the search, we used the keywords: (Plasmodium Berghei) AND (Malaria) AND (Parasitemia) AND (antimalarial activity) AND (nanoparticles) AND (Solid lipid NPS) AND (Nano lipid carriers) AND (Artemether) AND (Chloroquine) AND (intraperitoneal) AND (in vivo). Initially, a total of 160 studies were retrieved from the search. After removing duplicates, 80 studies remained. After reviewing the title and abstract of each study, 45 unrelated studies were eliminated. RESULTS: The remaining 35 studies were thoroughly reviewed using the full texts. The final result was 21 studies that met the inclusion/exclusion criteria. CONCLUSION: Using these findings, we can conclude that various nanoparticles possess antiparasitic effects that may be applied to emerging and drug-resistant parasites. Together, these findings suggest that nanostructures may be used to design antiparasitic drugs that are effective against Plasmodium berghei.

The Language of Social Touch Is Intuitive and Quantifiable.

Touch is a powerful communication tool, but we have a limited understanding of the role played by particular physical features of interpersonal touch communication. In this study, adults living in Sweden performed a task in which messages (attention, love, happiness, calming, sadness, and gratitude) were conveyed by a sender touching the forearm of a receiver, who interpreted the messages. Two experiments (N = 32, N = 20) showed that within close relationships, receivers could identify the intuitive touch expressions of the senders, and we characterized the physical features of the touches associated with successful communication. Facial expressions measured with electromyography varied by message but were uncorrelated with communication performance. We developed standardized touch expressions and quantified the physical features with 3D hand tracking. In two further experiments (N = 20, N = 16), these standardized expressions were conveyed by trained senders and were readily understood by strangers unacquainted with the senders. Thus, the possibility emerges of a standardized, intuitively understood language of social touch.

A Wearable Textile-Embedded Dielectric Elastomer Actuator Haptic Display.

With advances in mobile computing and virtual/augmented reality technologies, communicating through touch using wearable haptic devices is poised to enrich and augment current information delivery channels that typically rely on sight and hearing. To realize a wearable haptic device capable of effective data communication, both ergonomics and haptic performance (i.e., array size, bandwidth, and perception accuracy) are essential considerations. However, these goals often involve challenging and conflicting requirements. We present an integrated approach to address these conflicts, which includes incorporating multilayered dielectric elastomer actuators, a lumped-parameter model of the skin, and a wearable frame in the design loop. An antagonistic arrangement-consisting of an actuator deforming the skin-was used to achieve effective force transmission while maintaining a low profile, and the effect of the wearable frame and structure was investigated through lumped-model analysis and human perception studies.

An Online Survey on the Perception of Mediated Social Touch Interaction and Device Design.

Social touch is essential for our social interactions, communication, and well-being. It has been shown to reduce anxiety and loneliness; and is a key channel to transmit emotions for which words are not sufficient, such as love, sympathy, reassurance. However, direct physical contact is not always possible due to being remotely located, interacting in a virtual environment, or as a result of a health issue. Mediated social touch enables physical interactions, despite the distance, by transmitting the haptic cues that constitute social touch through devices. As this technology is fairly new, the users' needs and their expectations on a device design and its features are unclear, as well as who would use this technology, and in which conditions. To better understand these aspects of mediated interaction, we conducted an online survey on 258 respondents located in the USA. Results give insights on the type of interactions and device features that the US population would like to use.

Data-Driven Sparse Skin Stimulation Can Convey Social Touch Information to Humans.

During social interactions, people use auditory, visual, and haptic cues to convey their thoughts, emotions, and intentions. Due to weight, energy, and other hardware constraints, it is difficult to create devices that completely capture the complexity of human touch. Here we explore whether a sparse representation of human touch is sufficient to convey social touch signals. To test this we collected a dataset of social touch interactions using a soft wearable pressure sensor array, developed an algorithm to map recorded data to an array of actuators, then applied our algorithm to create signals that drive an array of normal indentation actuators placed on the arm. Using this wearable, low-resolution, low-force device, we find that users are able to distinguish the intended social meaning, and compare performance to results based on direct human touch. As online communication becomes more prevalent, such systems to convey haptic signals could allow for improved distant socializing and empathetic remote human-human interaction.

A Wearable Soft Haptic Communicator Based on Dielectric Elastomer Actuators.

Dielectric elastomer actuators exhibit an unusual combination of large displacements, moderate bandwidth, low power consumption, and mechanical impedance comparable with human skin, making them attractive for haptic devices. In this article, we propose a wearable haptic communication device based on a two-by-two array of dielectric elastomer linear actuators. We briefly describe the architecture of the actuators and their mechanical and electrical integration into a wearable armband. We then characterize the actuators' force, displacement, and thermal properties in a bench-top configuration. We also report on the power and drive circuit design. Finally, we perform a set of preliminary perception evaluations on participants using our haptic device, including detection threshold tests and identification tests for locations and directions on the forearm. Human testing with individual actuators demonstrates that the broadband actuation can be easily perceived on the forearm, providing the basis for both the development of a wearable actuator array and its use in more extensive perception evaluation as described herein.

Multi-Sensory Stimuli Improve Distinguishability of Cutaneous Haptic Cues.

Wearable haptic systems offer portable, private tactile communication to a human user. To date, advances in wearable haptic devices have typically focused on the optimization of haptic cue transmission using a single modality, or have combined two types of cutaneous feedbacks, each mapped to a particular parameter of the task. Alternatively, researchers have employed arrays of haptic tactile actuators to maximize information throughput to a user. However, when large cue sets are to be transmitted, such as those required to communicate language, perceptual interference between transmitted cues can decrease the efficacy of single-sensory systems, or require large footprints to ensure salient spatiotemporal cues are rendered to the user. In this paper, we present a wearable, multi-sensory haptic feedback system, MISSIVE (Multi-sensory Interface of Stretch, Squeeze, and Integrated Vibration Elements), that conveys multi-sensory haptic cues to the user's upper arm. We present experimental results that demonstrate that rendering haptic cues with multi-sensory components-specifically, lateral skin stretch, radial squeeze, and vibrotactile stimuli-improved perceptual distinguishability in comparison to similar cues with all-vibrotactile components. These results support the incorporation of diverse stimuli, both vibrotactile and nonvibrotactile, for applications requiring large haptic cue sets.

A Phonemic-Based Tactile Display for Speech Communication.

Despite a long history of research, the development of synthetic tactual aids to support the communication of speech has proven to be a difficult task. The current paper describes a new tactile speech device based on the presentation of phonemic-based tactile codes. The device consists of 24 tactors under independent control for stimulation at the forearm. Using properties that include frequency and waveform of stimulation, amplitude, spatial location, and movement characteristics, unique tactile codes were designed for 39 consonant and vowel phonemes of the English language. The strategy for mapping the phonemes to tactile symbols is described, and properties of the individual phonemic codes are provided. Results are reported for an exploratory study of the ability of 10 young adults to identify the tactile symbols. The participants were trained to identify sets of consonants and vowels, before being tested on the full set of 39 tactile codes. The results indicate a mean recognition rate of 86 percent correct within one to four hours of training across participants. Thus, these results support the viability of a phonemic-based approach for conveying speech information through the tactile sense.

Uncovering Human-to-Human Physical Interactions that Underlie Emotional and Affective Touch Communication.

Couples often communicate their emotions, e.g., love or sadness, through physical expressions of touch. Prior efforts have used visual observation to distinguish emotional touch communications by certain gestures tied to one's hand contact, velocity and position. The work herein describes an automated approach to eliciting the essential features of these gestures. First, a tracking system records the timing and location of contact interactions in 3-D between a toucher's hand and a receiver's forearm. Second, data post-processing algorithms extract dependent measures, derived from prior visual observation, tied to the intensity and velocity of the toucher's hand, as well as areas, durations and parts of the hand in contact. Third, behavioral data were obtained from five couples who sought to convey a variety of emotional word cues. We found that certain combinations of six dependent measures well distinguish the touch communications. For example, a typical sadness expression invokes more contact, evolves more slowly, and impresses less deeply into the forearm than a typical attention expression. Furthermore, cluster analysis indicates 2-5 distinct expression strategies are common per word being communicated. Specifying the essential features of touch communications can guide haptic devices in reproducing naturalistic interactions.

Intermanual Apparent Tactile Motion and Its Extension to 3D Interactions.

Information provided by sensory systems is inherently ambiguous as to its source in the physical world. To arrive at a coherent representation, perception deploys heuristic rules and multimodal input, which potentially produce errors such as illusions. The current work uses these effects to create apparent tactile motion and illusory depth motion using sparse vibrotactile stimulation across the hands. Experiment 1 showed the effects of vibrotactile duration and temporal separation between the hands on the quality of perceived illusory linear motion. Experiment 2 indicated a compressed linear relation between the visual and tactile speeds, and established a linear function relating visual size to perceived tactile intensity at three durations. Experiment 3 introduced an "M-filter" algorithm that varies tactile stimulus amplitude by a parabolic function based on visual looming and receding. It demonstrated that the M-filters, accompanied by visual depth cues, can induce tactile motion in depth. Experiment 4 showed the M-filter algorithm is necessary to create tactile perception in depth, as opposed to apparent tactile motion. The current research has value for a basic understanding of haptic perception, as well as haptic applications that digitally generate perceptual representations of the distal world on small-sized devices in the space between the hands.

Influence of an enforcement campaign on seat-belt and helmet wearing, karachi-hala highway, pakistan.

This study assessed to what extent an enforcement campaign influenced seat-belt and helmet wearing on a Pakistani highway. The study setting was the Karachi-Hala highway where a traffic enforcement campaign was conducted from Dec 2009 to Feb 2010. Seat-belt and helmet wearing were observed in Nov 2009 and Apr 2010 at Karachi toll plaza. Differences in wearing rates as a function of occupants' age, sex, and vehicle type were compared between the two periods. On average, 9 119 (Standard deviation=1 896) traffic citations were issued per month from Aug 2009 to Feb 2010; 4.2% of which were for not wearing helmet. A 22.5% increase in citations was observed for Dec 2009 to Feb 2010 periods compared with Aug 2009 to Oct 2009 periods. Nearly six thousand four-wheeled and four hundred two-wheeled motorized vehicle occupants were observed in Nov 2009 and Apr 2010. Overall, two of the five drivers and one of the five front seat occupants wore seat belts. This proportion was significantly higher in drivers and front-seat occupants of cars than those of heavier vehicles. Similarly, one of two motorcyclists used a helmet but this proportion was 5.8% for pillion riders in Nov 2009. The increased enforcement had a limited influence on belt wearing in drivers (+4.0%; 95% Confidence Interval [95%CI]=1.8-6.1) and occupants (+6.2%; 95%CI=4.2-8.2). A higher increase was observed for motorcyclists (+9.8%; 95%CI=2.6-16.8) and pillion riders (+12.8%; 95%CI=5.4, 20.5). These results suggested that serious efforts are required to increase seat-belt and helmet use on Pakistani highways. Improving enforcement resources, increased fines, not allowing such vehicles on roads, and awareness campaigns targeting drivers of heavy vehicles might increase wearing rates in Pakistan.

Controller design and consonantal contrast coding using a multi-finger tactual display.

This paper presents the design and evaluation of a new controller for a multi-finger tactual display in speech communication. A two-degree-of-freedom controller consisting of a feedback controller and a prefilter and its application in a consonant contrasting experiment are presented. The feedback controller provides stable, fast, and robust response of the fingerpad interface and the prefilter shapes the frequency-response of the closed-loop system to match with the human detection-threshold function. The controller is subsequently used in a speech communication system that extracts spectral features from recorded speech signals and presents them as vibrational-motional waveforms to three digits on a receiver's left hand. Performance from a consonantal contrast test suggests that participants are able to identify tactual cues necessary for discriminating consonants in the initial position of consonant-vowel-consonant (CVC) segments. The average sensitivity indices for contrasting voicing, place, and manner features are 3.5, 2.7, and 3.4, respectively. The results show that the consonantal features can be successfully transmitted by utilizing a broad range of the kinesthetic-cutaneous sensory system. The present study also demonstrates the validity of designing controllers that take into account not only the electromechanical properties of the hardware, but the sensory characteristics of the human user.

Frequency and amplitude discrimination along the kinestheticcutaneous continuum in the presence of masking stimuli.

Frequency and amplitude discrimination thresholds along the kinesthetic to cutaneous continuum were evaluated on the left index fingerpad using a multifinger tactual display. Target stimuli were presented either in isolation (no-masker condition) or in the presence of masking stimuli (one- or two-masker conditions). Six reference target signals in the frequency range 2-300 Hz (two each from low-, medium-, and high-frequency regions) and at an amplitude of either 20 or 35 dB sensation levels (SL) were used. In the no-masker condition, the range of frequency Weber fraction was 0.13-0.38 and 0.14-0.28, and the range of amplitude discrimination threshold was 1.82-2.98 dB and 1.65-2.71 dB, at 20 and 35 dB SL, respectively. In the masking conditions, average frequency Weber fractions rose to 0.60 and 0.46, and average amplitude thresholds rose to 3.63 and 3.72 dB, at 20 and 35 dB SL, respectively. In general, thresholds were largest in the two-masker condition and lowest in the no-masker condition. Although the frequency and amplitude thresholds generally increased in the presence of masking stimuli, there was some indication of channel independence for low- and high-frequency target stimuli. The implications of the results for tactual communication of speech are discussed.