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Sample records for based tongue-placed tactile

  1. Touch sensitive electrorheological fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-12-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5 × 5 tactile display array including electrorheological (ER) fluid has been developed and investigated. Force responses of the tactile display array have been measured while a probe was moved across the upper surface. The purpose of this was to simulate the action of touch performed by human finger. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. The performance of the tactile display is durable and repeatable. The touch sensitivity of this ER fluid based tactile display array has also been investigated in this research. The results show that it is possible to sense the touching force normal to the display's surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  2. Nanowire FET Based Neural Element for Robotic Tactile Sensing Skin

    Directory of Open Access Journals (Sweden)

    William Taube Navaraj

    2017-09-01

    Full Text Available This paper presents novel Neural Nanowire Field Effect Transistors (υ-NWFETs based hardware-implementable neural network (HNN approach for tactile data processing in electronic skin (e-skin. The viability of Si nanowires (NWs as the active material for υ-NWFETs in HNN is explored through modeling and demonstrated by fabricating the first device. Using υ-NWFETs to realize HNNs is an interesting approach as by printing NWs on large area flexible substrates it will be possible to develop a bendable tactile skin with distributed neural elements (for local data processing, as in biological skin in the backplane. The modeling and simulation of υ-NWFET based devices show that the overlapping areas between individual gates and the floating gate determines the initial synaptic weights of the neural network - thus validating the working of υ-NWFETs as the building block for HNN. The simulation has been further extended to υ-NWFET based circuits and neuronal computation system and this has been validated by interfacing it with a transparent tactile skin prototype (comprising of 6 × 6 ITO based capacitive tactile sensors array integrated on the palm of a 3D printed robotic hand. In this regard, a tactile data coding system is presented to detect touch gesture and the direction of touch. Following these simulation studies, a four-gated υ-NWFET is fabricated with Pt/Ti metal stack for gates, source and drain, Ni floating gate, and Al2O3 high-k dielectric layer. The current-voltage characteristics of fabricated υ-NWFET devices confirm the dependence of turn-off voltages on the (synaptic weight of each gate. The presented υ-NWFET approach is promising for a neuro-robotic tactile sensory system with distributed computing as well as numerous futuristic applications such as prosthetics, and electroceuticals.

  3. Nanowire FET Based Neural Element for Robotic Tactile Sensing Skin.

    Science.gov (United States)

    Taube Navaraj, William; García Núñez, Carlos; Shakthivel, Dhayalan; Vinciguerra, Vincenzo; Labeau, Fabrice; Gregory, Duncan H; Dahiya, Ravinder

    2017-01-01

    This paper presents novel Neural Nanowire Field Effect Transistors (υ-NWFETs) based hardware-implementable neural network (HNN) approach for tactile data processing in electronic skin (e-skin). The viability of Si nanowires (NWs) as the active material for υ-NWFETs in HNN is explored through modeling and demonstrated by fabricating the first device. Using υ-NWFETs to realize HNNs is an interesting approach as by printing NWs on large area flexible substrates it will be possible to develop a bendable tactile skin with distributed neural elements (for local data processing, as in biological skin) in the backplane. The modeling and simulation of υ-NWFET based devices show that the overlapping areas between individual gates and the floating gate determines the initial synaptic weights of the neural network - thus validating the working of υ-NWFETs as the building block for HNN. The simulation has been further extended to υ-NWFET based circuits and neuronal computation system and this has been validated by interfacing it with a transparent tactile skin prototype (comprising of 6 × 6 ITO based capacitive tactile sensors array) integrated on the palm of a 3D printed robotic hand. In this regard, a tactile data coding system is presented to detect touch gesture and the direction of touch. Following these simulation studies, a four-gated υ-NWFET is fabricated with Pt/Ti metal stack for gates, source and drain, Ni floating gate, and Al 2 O 3 high-k dielectric layer. The current-voltage characteristics of fabricated υ-NWFET devices confirm the dependence of turn-off voltages on the (synaptic) weight of each gate. The presented υ-NWFET approach is promising for a neuro-robotic tactile sensory system with distributed computing as well as numerous futuristic applications such as prosthetics, and electroceuticals.

  4. Fluid-structure interaction-based biomechanical perception model for tactile sensing.

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    Full Text Available The reproduced tactile sensation of haptic interfaces usually selectively reproduces a certain object attribute, such as the object's material reflected by vibration and its surface shape by a pneumatic nozzle array. Tactile biomechanics investigates the relation between responses to an external load stimulus and tactile perception and guides the design of haptic interface devices via a tactile mechanism. Focusing on the pneumatic haptic interface, we established a fluid-structure interaction-based biomechanical model of responses to static and dynamic loads and conducted numerical simulation and experiments. This model provides a theoretical basis for designing haptic interfaces and reproducing tactile textures.

  5. Performance of Brain-computer Interfacing based on tactile selective sensation and motor imagery

    DEFF Research Database (Denmark)

    Yao, Lin; Sheng, Xinjun; Mrachacz-Kersting, Natalie

    2018-01-01

    We proposed a multi-class tactile brain-computer interface that utilizes stimulus-induced oscillatory dynamics. It was hypothesized that somatosensory attention can modulate tactile induced oscillation changes, which can decode different sensation attention tasks. Subjects performed four tactile......-S). The classification accuracy between SS-L and SS-R (79.9±8.7%) was comparable with that of a previous tactile BCI system based on selective sensation. Moreover, the accuracy could be improved to an average of 90.3±4.9% by optimal class-pair and frequency-band selection. Three-class discrimination had accuracy of 75...

  6. Tactile sensor of hardness recognition based on magnetic anomaly detection

    Science.gov (United States)

    Xue, Lingyun; Zhang, Dongfang; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    Hardness, as one kind of tactile sensing, plays an important role in the field of intelligent robot application such as gripping, agricultural harvesting, prosthetic hand and so on. Recently, with the rapid development of magnetic field sensing technology with high performance, a number of magnetic sensors have been developed for intelligent application. The tunnel Magnetoresistance(TMR) based on magnetoresistance principal works as the sensitive element to detect the magnetic field and it has proven its excellent ability of weak magnetic detection. In the paper, a new method based on magnetic anomaly detection was proposed to detect the hardness in the tactile way. The sensor is composed of elastic body, ferrous probe, TMR element, permanent magnet. When the elastic body embedded with ferrous probe touches the object under the certain size of force, deformation of elastic body will produce. Correspondingly, the ferrous probe will be forced to displace and the background magnetic field will be distorted. The distorted magnetic field was detected by TMR elements and the output signal at different time can be sampled. The slope of magnetic signal with the sampling time is different for object with different hardness. The result indicated that the magnetic anomaly sensor can recognize the hardness rapidly within 150ms after the tactile moment. The hardness sensor based on magnetic anomaly detection principal proposed in the paper has the advantages of simple structure, low cost, rapid response and it has shown great application potential in the field of intelligent robot.

  7. A ferrofluid based artificial tactile sensor with magnetic field control

    International Nuclear Information System (INIS)

    Volkova, T.I.; Böhm, V.; Naletova, V.A.; Kaufhold, T.; Becker, F.; Zeidis, I.; Zimmermann, K.

    2017-01-01

    The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of periodically altering direction. - Highlights: • A design approach of a tactile sensor inspired by special mammalian hairs is presented. • The working principle is based on magnetic properties of a ferrofluid in magnetic fields. • The magnetic force acting on a body submerged into a ferrofluid volume is evaluated. • External mechanical stimuli may be identified by the distortion of the magnetic field. • The controlled whisking-like oscillations of the sensor's rod are realised experimentally.

  8. A ferrofluid based artificial tactile sensor with magnetic field control

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, T.I., E-mail: tatiana.volkova@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Böhm, V., E-mail: valter.boehm@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Naletova, V.A., E-mail: naletova@imec.msu.ru [Faculty of Mechanics and Mathematics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Kaufhold, T., E-mail: tobias.kaufhold@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Becker, F., E-mail: felix.becker@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Zeidis, I., E-mail: igor.zeidis@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany); Zimmermann, K., E-mail: klaus.zimmermann@tu-ilmenau.de [Technical Mechanics Group, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau D-98684 (Germany)

    2017-06-01

    The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of periodically altering direction. - Highlights: • A design approach of a tactile sensor inspired by special mammalian hairs is presented. • The working principle is based on magnetic properties of a ferrofluid in magnetic fields. • The magnetic force acting on a body submerged into a ferrofluid volume is evaluated. • External mechanical stimuli may be identified by the distortion of the magnetic field. • The controlled whisking-like oscillations of the sensor's rod are realised experimentally.

  9. A ferrofluid based artificial tactile sensor with magnetic field control

    Science.gov (United States)

    Volkova, T. I.; Böhm, V.; Naletova, V. A.; Kaufhold, T.; Becker, F.; Zeidis, I.; Zimmermann, K.

    2017-06-01

    The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of periodically altering direction.

  10. Fabrication of strain gauge based sensors for tactile skins

    Science.gov (United States)

    Baptist, Joshua R.; Zhang, Ruoshi; Wei, Danming; Saadatzi, Mohammad Nasser; Popa, Dan O.

    2017-05-01

    Fabricating cost effective, reliable and functional sensors for electronic skins has been a challenging undertaking for the last several decades. Application of such skins include haptic interfaces, robotic manipulation, and physical human-robot interaction. Much of our recent work has focused on producing compliant sensors that can be easily formed around objects to sense normal, tension, or shear forces. Our past designs have involved the use of flexible sensors and interconnects fabricated on Kapton substrates, and piezoresistive inks that are 3D printed using Electro Hydro Dynamic (EHD) jetting onto interdigitated electrode (IDE) structures. However, EHD print heads require a specialized nozzle and the application of a high-voltage electric field; for which, tuning process parameters can be difficult based on the choice of inks and substrates. Therefore, in this paper we explore sensor fabrication techniques using a novel wet lift-off photolithographic technique for patterning the base polymer piezoresistive material, specifically Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) or PEDOT:PSS. Fabricated sensors are electrically and thermally characterized, and temperaturecompensated designs are proposed and validated. Packaging techniques for sensors in polymer encapsulants are proposed and demonstrated to produce a tactile interface device for a robot.

  11. Optical based tactile shear and normal load sensor

    Energy Technology Data Exchange (ETDEWEB)

    Salisbury, Curt Michael

    2015-06-09

    Various technologies described herein pertain to a tactile sensor that senses normal load and/or shear load. The tactile sensor includes a first layer and an optically transparent layer bonded together. At least a portion of the first layer is made of optically reflective material. The optically transparent layer is made of resilient material (e.g., clear silicone rubber). The tactile sensor includes light emitter/light detector pair(s), which respectively detect either normal load or shear load. Light emitter(s) emit light that traverses through the optically transparent layer and reflects off optically reflective material of the first layer, and light detector(s) detect and measure intensity of reflected light. When a normal load is applied, the optically transparent layer compresses, causing a change in reflected light intensity. When shear load is applied, a boundary between optically reflective material and optically absorptive material is laterally displaced, causing a change in reflected light intensity.

  12. The Design of a Novel Flexible Tactile Sensor Based on Pressure-conductive Rubber

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2011-01-01

    Full Text Available A novel flexible tactile sensor using conductive rubber with electrical-wires knitted method is presented. The sensor’s design is based on rubber’s pressure-sensitive property. It is flexible and can be mounted on any object to measure tactile information. The mathematic piezoresistivity model of the rubber is described, and we also discuss the sensor’s structure and scanning method. The simulation results show that the sensor can detect pressure accurately.

  13. A novel flexible tactile sensor based on Ce-doped BaTiO3 nanofibers

    Science.gov (United States)

    Zhuang, Yongyong; Xu, Zhuo; Fu, Xiaotian; Li, Fei; Li, Jinglei; Liao, Zhipeng; Liu, Weihua

    2017-07-01

    The performance of a robotic hand is severely limited by the tactile feedback information similar to a human hand. Hence, a novel and robust tactile sensor has been developed to cope with the challenge of robotic hand technology. Piezoelectric material is proposed as a suitable candidate for a new efficient tactile sensor due to its excellent piezoelectric properties. In this paper, a novel flexible tactile sensor based on Ce-doped BTO nanofibers was developed. The doping mechanism of cerium ions and the working process of the sensor were analysed. The results showed that sheer stress had no contribution to the sensor, this indicated that the sensor was easy to control according to the individual’s wish. The output voltage of the sensor could reach up to 0.078 V which showed great potential for the future of intelligent robot skin application.

  14. Flexible Tactile Sensing Based on Piezoresistive Composites: A Review

    Directory of Open Access Journals (Sweden)

    Stefano Stassi

    2014-03-01

    Full Text Available The large expansion of the robotic field in the last decades has created a growing interest in the research and development of tactile sensing solutions for robot hand and body integration. Piezoresistive composites are one of the most widely employed materials for this purpose, combining simple and low cost preparation with high flexibility and conformability to surfaces, low power consumption, and the use of simple read-out electronics. This work provides a review on the different type of composite materials, classified according to the conduction mechanism and analyzing the physics behind it. In particular piezoresistors, strain gauges, percolative and quantum tunnelling devices are reviewed here, with a perspective overview on the most used filler types and polymeric matrices. A description of the state-of-the-art of the tactile sensor solutions from the point of view of the architecture, the design and the performance is also reviewed, with a perspective outlook on the main promising applications.

  15. Flexible Capacitive Tactile Sensor Based on Micropatterned Dielectric Layer.

    Science.gov (United States)

    Li, Tie; Luo, Hui; Qin, Lin; Wang, Xuewen; Xiong, Zuoping; Ding, Haiyan; Gu, Yang; Liu, Zheng; Zhang, Ting

    2016-09-01

    Flexible tactile sensors are considered as an effective way to realize the sense of touch, which can perform the synchronized interactions with surrounding environment. Here, the utilization of bionic microstructures on natural lotus leaves is demonstrated to design and fabricate new-type of high-performance flexible capacitive tactile sensors. Taking advantage of unique surface micropattern of lotus leave as the template for electrodes and using polystyrene microspheres as the dielectric layer, the proposed devices present stable and high sensing performance, such as high sensitivity (0.815 kPa -1 ), wide dynamic response range (from 0 to 50 N), and fast response time (≈38 ms). In addition, the flexible capacitive sensor is not only applicable to pressure (touch of a single hair), but also to bending and stretching forces. The results indicate that the proposed capacitive tactile sensor is a promising candidate for the future applications in electronic skins, wearable robotics, and biomedical devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. E-Pad: a comfortable electrocutaneous-based tactile feedback display

    Science.gov (United States)

    Wang, Jiabin; Zhao, Lu; Liu, Yue; Wang, Yongtian; Cai, Yi

    2018-01-01

    The devices with touchscreen are becoming more popular recently; however, most of them suffer from the crucial drawbacks of lacking accurate tactile feedback. A novel electrocutaneous-based tactile device with the name of E-pad is proposed to provide a dynamic and static low-voltage feedback for touchscreen. We optimize the key parameters of the output voltage and design custom-made hardwares to guarantee a comfortable user experience. Users could move their fingers freely across the touchscreen of the proposed device to really feel virtual objects. Two preliminary experiments are conducted to evaluate the interactive performance of the proposed device and the experimental results show that the proposed device can provide a comfortable and distinct tactile feedback.

  17. Investigation of the touch sensitivity of ER fluid based tactile display

    Science.gov (United States)

    Liu, Yanju; Davidson, Rob; Taylor, Paul

    2005-05-01

    A tactile display is programmable device whose controlled surface is intended to be investigated by human touch. It has a great number of potential applications in the field of virtual reality and elsewhere. In this research, a 5x5 touch sensitive tactile display array including electrorheological (ER) fluid has been developed and investigated. Experimental results show that the sensed surface information could be controlled effectively by adjusting the voltage activation pattern imposed on the tactels. In the meantime, it is possible to sense the touching force normal to the display"s surface by monitoring the change of current passing through the ER fluid. These encouraging results are helpful for constructing a new type of tactile display based on ER fluid which can act as both sensor and actuator at the same time.

  18. Tactile-Sensing Based on Flexible PVDF Nanofibers via Electrospinning: A Review.

    Science.gov (United States)

    Wang, Xiaomei; Sun, Fazhe; Yin, Guangchao; Wang, Yuting; Liu, Bo; Dong, Mingdong

    2018-01-24

    The flexible tactile sensor has attracted widespread attention because of its great flexibility, high sensitivity, and large workable range. It can be integrated into clothing, electronic skin, or mounted on to human skin. Various nanostructured materials and nanocomposites with high flexibility and electrical performance have been widely utilized as functional materials in flexible tactile sensors. Polymer nanomaterials, representing the most promising materials, especially polyvinylidene fluoride (PVDF), PVDF co-polymer and their nanocomposites with ultra-sensitivity, high deformability, outstanding chemical resistance, high thermal stability and low permittivity, can meet the flexibility requirements for dynamic tactile sensing in wearable electronics. Electrospinning has been recognized as an excellent straightforward and versatile technique for preparing nanofiber materials. This review will present a brief overview of the recent advances in PVDF nanofibers by electrospinning for flexible tactile sensor applications. PVDF, PVDF co-polymers and their nanocomposites have been successfully formed as ultrafine nanofibers, even as randomly oriented PVDF nanofibers by electrospinning. These nanofibers used as the functional layers in flexible tactile sensors have been reviewed briefly in this paper. The β-phase content, which is the strongest polar moment contributing to piezoelectric properties among all the crystalline phases of PVDF, can be improved by adjusting the technical parameters in electrospun PVDF process. The piezoelectric properties and the sensibility for the pressure sensor are improved greatly when the PVDF fibers become more oriented. The tactile performance of PVDF composite nanofibers can be further promoted by doping with nanofillers and nanoclay. Electrospun P(VDF-TrFE) nanofiber mats used for the 3D pressure sensor achieved excellent sensitivity, even at 0.1 Pa. The most significant enhancement is that the aligned electrospun core-shell P

  19. Tactile-Sensing Based on Flexible PVDF Nanofibers via Electrospinning: A Review

    Directory of Open Access Journals (Sweden)

    Xiaomei Wang

    2018-01-01

    Full Text Available The flexible tactile sensor has attracted widespread attention because of its great flexibility, high sensitivity, and large workable range. It can be integrated into clothing, electronic skin, or mounted on to human skin. Various nanostructured materials and nanocomposites with high flexibility and electrical performance have been widely utilized as functional materials in flexible tactile sensors. Polymer nanomaterials, representing the most promising materials, especially polyvinylidene fluoride (PVDF, PVDF co-polymer and their nanocomposites with ultra-sensitivity, high deformability, outstanding chemical resistance, high thermal stability and low permittivity, can meet the flexibility requirements for dynamic tactile sensing in wearable electronics. Electrospinning has been recognized as an excellent straightforward and versatile technique for preparing nanofiber materials. This review will present a brief overview of the recent advances in PVDF nanofibers by electrospinning for flexible tactile sensor applications. PVDF, PVDF co-polymers and their nanocomposites have been successfully formed as ultrafine nanofibers, even as randomly oriented PVDF nanofibers by electrospinning. These nanofibers used as the functional layers in flexible tactile sensors have been reviewed briefly in this paper. The β-phase content, which is the strongest polar moment contributing to piezoelectric properties among all the crystalline phases of PVDF, can be improved by adjusting the technical parameters in electrospun PVDF process. The piezoelectric properties and the sensibility for the pressure sensor are improved greatly when the PVDF fibers become more oriented. The tactile performance of PVDF composite nanofibers can be further promoted by doping with nanofillers and nanoclay. Electrospun P(VDF-TrFE nanofiber mats used for the 3D pressure sensor achieved excellent sensitivity, even at 0.1 Pa. The most significant enhancement is that the aligned

  20. A flexible tactile sensor calibration method based on an air-bearing six-dimensional force measurement platform

    Science.gov (United States)

    Huang, Bin

    2015-07-01

    A number of common issues related to the process of flexible tactile sensor calibration are discussed in this paper, and an estimate of the accuracy of classical calibration methods, as represented by a weight-pulley device, is presented. A flexible tactile sensor calibration method that is based on a six-dimensional force measurement is proposed on the basis of a theoretical analysis. A high-accuracy flexible tactile sensor calibration bench based on the air-bearing six-dimensional force measurement principle was developed to achieve a technically challenging measurement accuracy of 2% full scale (FS) for three-dimensional (3D) flexible tactile sensor calibration. The experimental results demonstrate that the accuracy of the air-bearing six-dimensional force measurement platform can reach 0.2% FS. Thus, the system satisfies the 3D flexible tactile sensor calibration requirement of 2% FS.

  1. Research of a Novel Three-dimensional Force Flexible Tactile Sensor Based on Conductive Rubber

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2010-09-01

    Full Text Available A novel three-dimensional force flexible tactile sensor using conductive rubber with "overall injection molding" technique is presented. The sensor is based on conductive rubber’s force-sensitive property. The sensor is flexible and can measure 3-D force. The rubber’s characteristics, the sensor’s structure and its principle are described. The results of simulation will be also presented.

  2. A sensory feedback system for prosthetic hand based on evoked tactile sensation.

    Science.gov (United States)

    Liu, X X; Chai, G H; Qu, H E; Lan, N

    2015-01-01

    The lack of reliable sensory feedback has been one of the barriers in prosthetic hand development. Restoring sensory function from prosthetic hand to amputee remains a great challenge to neural engineering. In this paper, we present the development of a sensory feedback system based on the phenomenon of evoked tactile sensation (ETS) at the stump skin of residual limb induced by transcutaneous electrical nerve stimulation (TENS). The system could map a dynamic pattern of stimuli to an electrode placed on the corresponding projected finger areas on the stump skin. A pressure transducer placed at the tip of prosthetic fingers was used to sense contact pressure, and a high performance DSP processor sampled pressure signals, and calculated the amplitude of feedback stimulation in real-time. Biphasic and charge-balanced current pulses with amplitude modulation generated by a multi-channel laboratory stimulator were delivered to activate sensory nerves beneath the skin. We tested this sensory feedback system in amputee subjects. Preliminary results showed that the subjects could perceive different levels of pressure at the tip of prosthetic finger through evoked tactile sensation (ETS) with distinct grades and modalities. We demonstrated the feasibility to restore the perceptual sensation from prosthetic fingers to amputee based on the phenomenon of evoked tactile sensation (ETS) with TENS.

  3. The potential for developing a tactile communication system based on Blissymbolics.

    Science.gov (United States)

    Isaacson, Mick D; Lloyd, Lyle L

    2015-02-01

    To be useful for tactile communication, tactile stimuli need to be discriminable from each other. The objective of this study was to determine whether raised-line renderings of Blissymbols have the capacity for being developed into a tactile communication system as measured by their tactile discriminability. Tactile discrimination of Blissymbols was measured by performance on a task in which participants were asked to feel a target raised-line Blissymbol and then to find the target within an array containing the target and raised-line Blissymbol foils. The vast majority of tactile Blissymbols had tactile discrimination scores of 90% accuracy or better. Most raised-line Blissymbols can be tactilely discriminated from each other, indicating that they have the potential for being developed into a tactile communication system.

  4. Design and simulation of a tactile display based on a CMUT array

    Science.gov (United States)

    Chouvardas, Vasilios G.; Hatalis, Miltiadis K.; Miliou, Amalia N.

    2012-10-01

    In this article, we present the design of a tactile display based on a CMUT-phased array. The array implements a 'pixel' of the display and is used to focus airborne ultrasound energy on the skin surface. The pressure field, generated by the focused ultrasound waves, is used to excite the mechanoreceptors under the skin and transmit tactile information. The results of Finite Element Analysis (FEA) of the Capacitive Micromachined Ultrasonic Transducer (CMUT) and the CMUT-phased array for ultrasound emission are presented. The 3D models of the device and the array were developed using a commercial FEA package. Modelling and simulations were performed using the parameters from the POLYMUMPS surface micromachining technology from MEMSCAP. During the analysis of the phased array, several parameters were studied in order to determine their importance in the design of the tactile display. The output of the array is compared with the acoustic intensity thresholds in order to prove the feasibility of the design. Taking into account the density of the mechanoreceptors in the skin, we conclude that there should be at least one receptor under the excitation area formed on the skin.

  5. A dielectric elastomer actuator-based tactile display for multiple fingertip interaction with virtual soft bodies

    Science.gov (United States)

    Boys, Hugh; Frediani, Gabriele; Poslad, Stefan; Busfield, James; Carpi, Federico

    2017-04-01

    This paper presents a novel wearable tactile haptic display for rendering soft body sensations to multiple fingertips with electroactive smart elastomers. The system uses newly developed multi-layered hydrostatically coupled dielectric elastomer actuators (DEAs), which have been designed to apply a localised tunable force to a user's fingertip via a soft electrically-deformable interface. The system is comprised of DEAs which are fingertip mounted and are driven individually by a wired connection to a control unit. The force applied to the user's fingertip is based on the user's fingertip position which is monitored by an optical three dimensional finger tracking system. This novel tactile display system is conceived to convey soft body interactions within virtual environments. To demonstrate this, a simulator capable of demonstrating virtual objects of varying tactile haptic properties has been developed. This paper presents preliminary results of ongoing testing, as well as data pertaining to the characterization of the device in terms of force response. The paper also outlines the current limitations of the proposed technology and challenges to be addressed for further developments.

  6. Evaluation of the MEMS based portable respiratory training system with a tactile sensor for respiratory-gated radiotherapy

    Science.gov (United States)

    Moon, Sun Young; Yoon, Myonggeun; Chung, Mijoo; Chung, Weon Kuu; Kim, Dong Wook

    2017-10-01

    In respiratory-gated radiotherapy, it is important to maintain the regular respiratory cycles of patients. If patients undergo respiration training, their regular breathing pattern is affected. Therefore, we developed a respiratory training system based on a micro electromechanical system (MEMS) and evaluated the feasibility of the MEMS in radiotherapy. By comparing the measured signal before and after radiation exposure, we confirmed the effects of radiation. By evaluating the period of the electric signal emitted by a tactile sensor and its constancy, the performance of the tactile sensor was confirmed. Moreover, by comparing the delay between the motion of the MEMS and the electric signal from the tactile sensor, we confirmed the reaction time of the tactile sensor. The results showed that a baseline shift occurred for an accumulated dose of 400 Gy in the sensor, and both the amplitude and period changed. The period of the signal released by the tactile sensor was 5.39 and its standard deviation was 0.06. Considering the errors from the motion phantom, a standard deviation of 0.06 was desirable. The delay time was within 0.5 s and not distinguishable by a patient. We confirmed the performance of the MEMS and concluded that MEMS could be applied to patients for respiratory-gated radiotherapy.

  7. Contact State Estimation by Vision-based Tactile Sensors for Dexterous Manipulation with Robot Hands Based on Shape-Sensing

    Directory of Open Access Journals (Sweden)

    Yuji Ito

    2011-09-01

    Full Text Available We propose a new method for estimating the contact state of objects with varying shapes on a vision‐ based fluid‐type tactile sensor, which touch pad is an elastic transparent membrane of silicon rubber with dotted pattern printed on its inner side. The membrane is filled with translucent red colored water. The proposed method leads to better understanding of the object

  8. Contact State Estimation by Vision-Based Tactile Sensors for Dexterous Manipulation with Robot Hands Based on Shape-Sensing

    Directory of Open Access Journals (Sweden)

    Yuji Ito

    2011-09-01

    Full Text Available We propose a new method for estimating the contact state of objects with varying shapes on a vision-based fluid-type tactile sensor, which touch pad is an elastic transparent membrane of silicon rubber with dotted pattern printed on its inner side. The membrane is filled with translucent red colored water. The proposed method leads to better understanding of the object's shape and movement, and can be applied for accomplishing reliable and dexterous handling tasks by robot hands.

  9. Driving Interface Based on Tactile Sensors for Electric Wheelchairs or Trolleys

    Directory of Open Access Journals (Sweden)

    Andrés Trujillo-León

    2014-02-01

    Full Text Available This paper introduces a novel device based on a tactile interface to replace the attendant joystick in electric wheelchairs. It can also be used in other vehicles such as shopping trolleys. Its use allows intuitive driving that requires little or no training, so its usability is high. This is achieved by a tactile sensor located on the handlebar of the chair or trolley and the processing of the information provided by it. When the user interacts with the handle of the chair or trolley, he or she exerts a pressure pattern that depends on the intention to accelerate, brake or turn to the left or right. The electronics within the device then perform the signal conditioning and processing of the information received, identifying the intention of the user on the basis of this pattern using an algorithm, and translating it into control signals for the control module of the wheelchair. These signals are equivalent to those provided by a joystick. This proposal aims to help disabled people and their attendees and prolong the personal autonomy in a context of aging populations.

  10. Nitride-Based Materials for Flexible MEMS Tactile and Flow Sensors in Robotics.

    Science.gov (United States)

    Abels, Claudio; Mastronardi, Vincenzo Mariano; Guido, Francesco; Dattoma, Tommaso; Qualtieri, Antonio; Megill, William M; De Vittorio, Massimo; Rizzi, Francesco

    2017-05-10

    The response to different force load ranges and actuation at low energies is of considerable interest for applications of compliant and flexible devices undergoing large deformations. We present a review of technological platforms based on nitride materials (aluminum nitride and silicon nitride) for the microfabrication of a class of flexible micro-electro-mechanical systems. The approach exploits the material stress differences among the constituent layers of nitride-based (AlN/Mo, Si x N y /Si and AlN/polyimide) mechanical elements in order to create microstructures, such as upwardly-bent cantilever beams and bowed circular membranes. Piezoresistive properties of nichrome strain gauges and direct piezoelectric properties of aluminum nitride can be exploited for mechanical strain/stress detection. Applications in flow and tactile sensing for robotics are described.

  11. Nitride-Based Materials for Flexible MEMS Tactile and Flow Sensors in Robotics

    Science.gov (United States)

    Abels, Claudio; Mastronardi, Vincenzo Mariano; Guido, Francesco; Dattoma, Tommaso; Qualtieri, Antonio; Megill, William M.; De Vittorio, Massimo; Rizzi, Francesco

    2017-01-01

    The response to different force load ranges and actuation at low energies is of considerable interest for applications of compliant and flexible devices undergoing large deformations. We present a review of technological platforms based on nitride materials (aluminum nitride and silicon nitride) for the microfabrication of a class of flexible micro-electro-mechanical systems. The approach exploits the material stress differences among the constituent layers of nitride-based (AlN/Mo, SixNy/Si and AlN/polyimide) mechanical elements in order to create microstructures, such as upwardly-bent cantilever beams and bowed circular membranes. Piezoresistive properties of nichrome strain gauges and direct piezoelectric properties of aluminum nitride can be exploited for mechanical strain/stress detection. Applications in flow and tactile sensing for robotics are described. PMID:28489040

  12. The output characteristic of cantilever-like tactile sensor based on the inverse magnetostrictive effect

    Directory of Open Access Journals (Sweden)

    Lili Wan

    2017-05-01

    Full Text Available The output characteristic model of a magnetostrictive cantilever-like tactile sensor has been founded based on the inverse-magnetostrictive effect, the flexure mode, and the Jiles-Atherton model. The magnetostrictive sensor has been designed and an output voltage is analyzed under the conditions of bias magnetic field, contact pressure and deflection of cantilever beam. The experiment has been performed to determine the relation among the induced output voltage, bias magnetic field, and pressure. It is found that the peak of the induced output voltage increases with an increasing pressure under the bias magnetic field of 4.8kA/m. The experimental result agrees well with the theoretical one and it means that the model can describe the relation among the induced output voltage, bias magnetic field, and pressure. The sensor with a Galfenol sheet may hold potentials in sample characterization and deformation predication in artificial intelligence area.

  13. Bio-Inspired PVDF-Based, Mouse Whisker Mimicking, Tactile Sensor

    Directory of Open Access Journals (Sweden)

    Mohsin Islam Tiwana

    2016-10-01

    Full Text Available The design and fabrication of a Polyvinylidene fluoride (PVDF based, mouse (or rodent whisker mimicking, tactile sensor is presented. Unlike previous designs reported in the literature, this sensor mimics the mouse whisker not only mechanically, but it also makes macro movements just like a real mouse whisker in a natural environment. We have developed a mathematical model and performed finite element analysis using COMSOL, in order to optimise the whisker to have the same natural frequency as that of a biological whisker. Similarly, we have developed a control system that enables the whisker mimicking sensor to vibrate at variable frequencies and conducted practical experiments to validate the response of the sensor. The natural frequency of the whisker can be designed anywhere between 35 and 110 Hz, the same as a biological whisker, by choosing different materials and physical dimensions. The control system of this sensor enables the whisker to vibrate between 5 and 236 Hz.

  14. High Resolution Flexible Tactile Sensors

    DEFF Research Database (Denmark)

    Drimus, Alin; Bilberg, Arne

    2011-01-01

    This paper describes the development of a tactile sensor for robotics inspired by the human sense of touch. It consists of two parts: a static tactile array sensor based on piezoresistive rubber and a dynamic sensor based on piezoelectric PVDF film. The combination of these two layers addresses...

  15. Enhanced Motor Imagery-Based BCI Performance via Tactile Stimulation on Unilateral Hand

    Directory of Open Access Journals (Sweden)

    Xiaokang Shu

    2017-12-01

    Full Text Available Brain-computer interface (BCI has attracted great interests for its effectiveness in assisting disabled people. However, due to the poor BCI performance, this technique is still far from daily-life applications. One of critical issues confronting BCI research is how to enhance BCI performance. This study aimed at improving the motor imagery (MI based BCI accuracy by integrating MI tasks with unilateral tactile stimulation (Uni-TS. The effects were tested on both healthy subjects and stroke patients in a controlled study. Twenty-two healthy subjects and four stroke patients were recruited and randomly divided into a control-group and an enhanced-group. In the control-group, subjects performed two blocks of conventional MI tasks (left hand vs. right hand, with 80 trials in each block. In the enhanced-group, subjects also performed two blocks of MI tasks, but constant tactile stimulation was applied on the non-dominant/paretic hand during MI tasks in the second block. We found the Uni-TS significantly enhanced the contralateral cortical activations during MI of the stimulated hand, whereas it had no influence on activation patterns during MI of the non-stimulated hand. The two-class BCI decoding accuracy was significantly increased from 72.5% (MI without Uni-TS to 84.7% (MI with Uni-TS in the enhanced-group (p < 0.001, paired t-test. Moreover, stroke patients in the enhanced-group achieved an accuracy >80% during MI with Uni-TS. This novel approach complements the conventional methods for BCI enhancement without increasing source information or complexity of signal processing. This enhancement via Uni-TS may facilitate clinical applications of MI-BCI.

  16. A silicon-based flexible tactile sensor for ubiquitous robot companion applications

    International Nuclear Information System (INIS)

    Kim, Kunnyun; Lee, Kang Ryeol; Lee, Dae Sung; Cho, Nam-Kyu; Kim, Won Hyo; Park, Kwang-Bum; Park, Hyo-Derk; Kim, Yong Kook; Park, Yon-Kyu; Kim, Jong-Ho

    2006-01-01

    We present the fabrication process and characteristics of a 3-axes flexible tactile sensor available for normal and shear mode fabricated using Si micromachining and packaging technologies. The fabrication processes for the 3 axes flexible tactile sensor were classified in the fabrication of sensor chips and their packaging on the flexible PCB. The variation rate of resistance was about 2.1%/N and 0.5%/N in applying normal and shear force, respectively. Because this tactile sensor can measure the variations of resistance of the semiconductor strain gauge for normal and shear force, it can be used to sense touch, pressure, hardness, and slip

  17. New Magnetic Microactuator Design Based on PDMS Elastomer and MEMS Technologies for Tactile Display.

    Science.gov (United States)

    Streque, Jeremy; Talbi, Abdelkrim; Pernod, Philippe; Preobrazhensky, Vladimir

    2010-01-01

    Highly efficient tactile display devices must fulfill technical requirements for tactile stimulation, all the while preserving the lightness and compactness needed for handheld operation. This paper focuses on the elaboration of highly integrated magnetic microactuators for tactile display devices. FEM simulation, conception, fabrication, and characterization of these microactuators are presented in this paper. The current demonstrator offers a 4 × 4 flexible microactuator array with a resolution of 2 mm. Each actuator is composed of a Poly (Dimethyl-Siloxane) (PDMS) elastomeric membrane, magnetically actuated by coil-magnet interaction. It represents a proof of concept for fully integrated MEMS tactile devices, with fair actuation forces provided for a power consumption up to 100 mW per microactuator. The prototypes are destined to provide both static and dynamic tactile sensations, with an optimized membrane geometry for actuation frequencies between DC and 350 Hz. On the basis of preliminary experiments, this display device can offer skin stimulations for various tactile stimuli for applications in the fields of Virtual Reality or Human-Computer Interaction (HCI). Moreover, the elastomeric material used in this device and its global compactness offer great advantages in matter of comfort of use and capabilities of integration in haptic devices.

  18. Slip Prediction through Tactile Sensing

    Directory of Open Access Journals (Sweden)

    Somrak PETCHARTEE

    2008-04-01

    Full Text Available This paper introduces a new way to predict contact slip using a resistive tactile sensor. The prototype sensor can be used to provide intrinsic information relating to geometrical features situated on the surface of grasped objects. Information along the gripper finger surface is obtained with a measurement resolution dependant on the number of discrete tactile elements. The tactile sensor predicts the partial slip of a tactile surface by sensing micro vibrations in tangential forces which are caused by an expansion of the slip regions within the contact area. The location of the local slip is not specified but its occurrence can be predicted immediately following micro vibration detection. Predictive models have been used to develop a set of rules which predict the slip based on fluctuations in tactile signal data.

  19. A droplet-based passive force sensor for remote tactile sensing applications

    Science.gov (United States)

    Nie, Baoqing; Yao, Ting; Zhang, Yiqiu; Liu, Jian; Chen, Xinjian

    2018-01-01

    A droplet-based flexible wireless force sensor has been developed for remote tactile-sensing applications. By integration of a droplet-based capacitive sensing unit and two circular planar coils, this inductor-capacitor (LC) passive sensor offers a platform for the mechanical force detection in a wireless transmitting mode. Under external loads, the membrane surface of the sensor deforms the underlying elastic droplet uniformly, introducing a capacitance response in tens of picofarads. The LC circuit transduces the applied force into corresponding variations of its resonance frequency, which is detected by an external electromagnetic coupling coil. Specifically, the liquid droplet features a mechanosensitive plasticity, which results in an increased device sensitivity as high as 2.72 MHz N-1. The high dielectric property of the droplet endows our sensor with high tolerance for noise and large capacitance values (20-40 pF), the highest value in the literature for the LC passive devices in comparable dimensions. It achieves excellent reproducibility under periodical loads ranging from 0 to 1.56 N and temperature fluctuations ranging from 10 °C to 55 °C. As an interesting conceptual demonstration, the flexible device has been configured into a fingertip-amounted setting in a highly compact package (of 11 mm × 11 mm × 0.25 mm) for remote contact force sensing in the table tennis game.

  20. Tactile Aids

    Directory of Open Access Journals (Sweden)

    Mohtaramossadat Homayuni

    1996-04-01

    Full Text Available Tactile aids, which translate sound waves into vibrations that can be felt by the skin, have been used for decades by people with severe/profound hearing loss to enhance speech/language development and improve speechreading.The development of tactile aids dates from the efforts of Goults and his co-workers in the 1920s; Although The power supply was too voluminous and it was difficult to carry specially by children, it was too huge and heavy to be carried outside the laboratories and its application was restricted to the experimental usage. Nowadays great advances have been performed in producing this instrument and its numerous models is available in markets around the world.

  1. Tactile-Sight: A Sensory Substitution Device Based on Distance-Related Vibrotactile Flow

    Directory of Open Access Journals (Sweden)

    Leandro Cancar

    2013-06-01

    Full Text Available Sensory substitution is a research field of increasing interest with regard to technical, applied and theoretical issues. Among the latter, it is of central interest to understand the form in which humans perceive the environment. Ecological psychology, among other approaches, proposes that we can detect higher-order informational variables (in the sense that they are defined over substantial spatial and temporal intervals that specify our interaction with the environment. When using a vibrotactile sensory substitution device, it is reasonable to ask if stimulation on the skin may be exploitable to detect higher-order variables. Motivated by this question, a portable vibrotactile sensory substitution device was built, using distance-based information as a source and driving a large number of vibrotactile actuators (72 in the reported version, 120 max. The portable device was designed to explore real environments, allowing natural unrestricted movement for the user while providing contingent real-time vibrotactile information. Two preliminary experiments were performed. In the first one, participants were asked to detect the time to contact of an approaching ball in a simulated (desktop environment. Reasonable performance was observed in all experimental conditions, including the one with only tactile stimulation. In the second experiment, a portable version of the device was used in a real environment, where participants were asked to hit an approaching ball. Participants were able to coordinate their arm movements with vibrotactile stimulation in appropriate timing. We conclude that vibrotactile flow can be generated by distance-based activation of the actuators and that this stimulation on the skin allows users to perceive time-to-contact related environmental properties.

  2. Stereo camera based virtual cane system with identifiable distance tactile feedback for the blind.

    Science.gov (United States)

    Kim, Donghun; Kim, Kwangtaek; Lee, Sangyoun

    2014-06-13

    In this paper, we propose a new haptic-assisted virtual cane system operated by a simple finger pointing gesture. The system is developed by two stages: development of visual information delivery assistant (VIDA) with a stereo camera and adding a tactile feedback interface with dual actuators for guidance and distance feedbacks. In the first stage, user's pointing finger is automatically detected using color and disparity data from stereo images and then a 3D pointing direction of the finger is estimated with its geometric and textural features. Finally, any object within the estimated pointing trajectory in 3D space is detected and the distance is then estimated in real time. For the second stage, identifiable tactile signals are designed through a series of identification experiments, and an identifiable tactile feedback interface is developed and integrated into the VIDA system. Our approach differs in that navigation guidance is provided by a simple finger pointing gesture and tactile distance feedbacks are perfectly identifiable to the blind.

  3. Stereo Camera Based Virtual Cane System with Identifiable Distance Tactile Feedback for the Blind

    Directory of Open Access Journals (Sweden)

    Donghun Kim

    2014-06-01

    Full Text Available In this paper, we propose a new haptic-assisted virtual cane system operated by a simple finger pointing gesture. The system is developed by two stages: development of visual information delivery assistant (VIDA with a stereo camera and adding a tactile feedback interface with dual actuators for guidance and distance feedbacks. In the first stage, user’s pointing finger is automatically detected using color and disparity data from stereo images and then a 3D pointing direction of the finger is estimated with its geometric and textural features. Finally, any object within the estimated pointing trajectory in 3D space is detected and the distance is then estimated in real time. For the second stage, identifiable tactile signals are designed through a series of identification experiments, and an identifiable tactile feedback interface is developed and integrated into the VIDA system. Our approach differs in that navigation guidance is provided by a simple finger pointing gesture and tactile distance feedbacks are perfectly identifiable to the blind.

  4. Gestural Communication With Accelerometer-Based Input Devices and Tactile Displays

    Science.gov (United States)

    2008-12-01

    belt assemblies The tactors are operated using a Tactor Control Unit ( TCU ) which is a computer-controlled driver/amplifier system that switches...each tactor on and off as required. This device is shown on the left side of the tactile display belts in Figure 3. The TCU weighs 1.2lbs independent

  5. Artificial Roughness Encoding with a Bio-inspired MEMS- based Tactile Sensor Array

    Science.gov (United States)

    Oddo, Calogero Maria; Beccai, Lucia; Felder, Martin; Giovacchini, Francesco; Carrozza, Maria Chiara

    2009-01-01

    A compliant 2×2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad. PMID:22412304

  6. Artificial Roughness Encoding with a Bio-inspired MEMS-based Tactile Sensor Array

    Directory of Open Access Journals (Sweden)

    Calogero Maria Oddo

    2009-04-01

    Full Text Available A compliant 2x2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad.

  7. A MEMS-based tactile sensor to study human digital touch: mechanical transduction of the tactile information and role of fingerprints

    Directory of Open Access Journals (Sweden)

    Scheibert J.

    2010-06-01

    Full Text Available We present recent results showing that human epidermal ridges (fingerprints could play a central role in fine texture discrimination tasks by spatially modulating the contact stress field between the fingertip and the substrate. Using an original biomimetic finger whose surface is patterned with parallel ridges, we demonstrate that the subsurface stress signals elicited by continuous rubbing of randomly textured substrates is dominated by fluctuations at a frequency defined by the inter-ridge distance divided by the rubbing velocity. In natural exploratory conditions, this frequency matches the best frequency of one type of mechanoreceptors, namely the Pacinian corpuscles, which are specifically involved in the tactile coding of fine textures. The use of white-noise patterned stimuli has alloowed us to extract, using a reverse-correlation analysis, the stimulus-signal response function associated with roughness modality. Its shape could provides spectral, spatial and directional selectivity to the digital tactile system. It offers a physiological basis for the recently proposed hypothesis of a dual-coding (spatio-temporal and vibratory of tactile information.

  8. Self-powered, ultra-sensitive, flexible tactile sensors based on contact electrification

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhong Lin; Zhu, Guang

    2018-03-20

    A tactile sensor for sensing touch from a human finger includes a triboelectric layer and includes a material that becomes electrically charged after being in contact with the finger. The first side of a first conductive layer is in contact with the second side of triboelectric layer. The first side of a dielectric layer is in contact with the first conductive layer and the second side of the dielectric layer is in contact with a second conductive layer. When the triboelectric layer becomes electrically charged after being in contact with the finger, the first conductive layer and the second conductive layer are subjected to an electric field, which has a first field strength at the first conductive layer and a second field strength, different from the first field strength, at the second conductive layer. A plurality of tactile sensors can be arranged as a keyboard.

  9. Perception-Based Tactile Soft Keyboard for the Touchscreen of Tablets

    Directory of Open Access Journals (Sweden)

    Kwangtaek Kim

    2018-01-01

    Full Text Available Most mobile devices equipped with touchscreens provide on-screen soft keyboard as an input method. However, many users are experiencing discomfort due to lack of physical feedback that causes slow typing speed and error-prone typing, as compared to the physical keyboard. To solve the problem, a platform-independent haptic soft keyboard suitable for tablet-sized touchscreens was proposed and developed. The platform-independent haptic soft keyboard was verified on both Android and Windows. In addition, a psychophysical experiment has been conducted to find an optimal strength of key click feedback on touchscreens, and the perception result was applied for making uniform tactile forces on touchscreens. The developed haptic soft keyboard can be easily integrated with existing tablets by putting the least amount of effort. The evaluation results confirm platform independency, fast tactile key click feedback, and uniform tactile force distribution on touchscreen with using only two piezoelectric actuators. The proposed system was developed on a commercial tablet (Mu Pad that has dual platforms (Android and Windows.

  10. Depth Camera-Based 3D Hand Gesture Controls with Immersive Tactile Feedback for Natural Mid-Air Gesture Interactions

    Directory of Open Access Journals (Sweden)

    Kwangtaek Kim

    2015-01-01

    Full Text Available Vision-based hand gesture interactions are natural and intuitive when interacting with computers, since we naturally exploit gestures to communicate with other people. However, it is agreed that users suffer from discomfort and fatigue when using gesture-controlled interfaces, due to the lack of physical feedback. To solve the problem, we propose a novel complete solution of a hand gesture control system employing immersive tactile feedback to the user’s hand. For this goal, we first developed a fast and accurate hand-tracking algorithm with a Kinect sensor using the proposed MLBP (modified local binary pattern that can efficiently analyze 3D shapes in depth images. The superiority of our tracking method was verified in terms of tracking accuracy and speed by comparing with existing methods, Natural Interaction Technology for End-user (NITE, 3D Hand Tracker and CamShift. As the second step, a new tactile feedback technology with a piezoelectric actuator has been developed and integrated into the developed hand tracking algorithm, including the DTW (dynamic time warping gesture recognition algorithm for a complete solution of an immersive gesture control system. The quantitative and qualitative evaluations of the integrated system were conducted with human subjects, and the results demonstrate that our gesture control with tactile feedback is a promising technology compared to a vision-based gesture control system that has typically no feedback for the user’s gesture inputs. Our study provides researchers and designers with informative guidelines to develop more natural gesture control systems or immersive user interfaces with haptic feedback.

  11. Whisking Kinematics Enables Object Localization in Head-Centered Coordinates Based on Tactile Information from a Single Vibrissa.

    Science.gov (United States)

    Yang, Anne E T; Hartmann, Mitra J Z

    2016-01-01

    During active tactile exploration with their whiskers (vibrissae), rodents can rapidly orient to an object even though there are very few proprioceptors in the whisker muscles. Thus a long-standing question in the study of the vibrissal system is how the rat can localize an object in head-centered coordinates without muscle-based proprioception. We used a three-dimensional model of whisker bending to simulate whisking motions against a peg to investigate the possibility that the 3D mechanics of contact from a single whisker are sufficient for localization in head-centered coordinates. Results show that for nearly all whiskers in the array, purely tactile signals at the whisker base - as would be measured by mechanoreceptors, in whisker-centered coordinates - could be used to determine the location of a vertical peg in head-centered coordinates. Both the "roll" and the "elevation" components of whisking kinematics contribute to the uniqueness and resolution of the localization. These results offer an explanation for a behavioral study showing that rats can more accurately determine the horizontal angle of an object if one column, rather than one row, of whiskers is spared.

  12. Whisking kinematics enables object localization in head-centered coordinates based on tactile information from a single vibrissa

    Directory of Open Access Journals (Sweden)

    Anne En-Tzu Yang

    2016-07-01

    Full Text Available During active tactile exploration with their whiskers (vibrissae, rodents can rapidly orient to an object even though there are very few proprioceptors in the whisker muscles. Thus a long-standing question in the study of the vibrissal system is how the rat can localize an object in head-centered coordinates without muscle-based proprioception. We used a three-dimensional model of whisker bending to simulate whisking motions against a peg to investigate the possibility that the 3D mechanics of contact from a single whisker are sufficient for localization in head-centered coordinates. Results show that, for nearly all whiskers in the array, purely tactile signals at the whisker base – as would be measured by mechanoreceptors, in whisker-centered coordinates – could be used to determine the location of a vertical peg in head-centered coordinates. Both the roll and the elevation components of whisking kinematics contribute to the uniqueness and resolution of the localization. These results offer an explanation for a behavioral study showing that rats can more accurately determine the horizontal angle of an object if one column, rather than one row, of whiskers is spared.

  13. Neural correlates of tactile detection: a combined magnetoencephalography and biophysically based computational modeling study.

    Science.gov (United States)

    Jones, Stephanie R; Pritchett, Dominique L; Stufflebeam, Steven M; Hämäläinen, Matti; Moore, Christopher I

    2007-10-03

    Previous reports conflict as to the role of primary somatosensory neocortex (SI) in tactile detection. We addressed this question in normal human subjects using whole-head magnetoencephalography (MEG) recording. We found that the evoked signal (0-175 ms) showed a prominent equivalent current dipole that localized to the anterior bank of the postcentral gyrus, area 3b of SI. The magnitude and timing of peaks in the SI waveform were stimulus amplitude dependent and predicted perception beginning at approximately 70 ms after stimulus. To make a direct and principled connection between the SI waveform and underlying neural dynamics, we developed a biophysically realistic computational SI model that contained excitatory and inhibitory neurons in supragranular and infragranular layers. The SI evoked response was successfully reproduced from the intracellular currents in pyramidal neurons driven by a sequence of lamina-specific excitatory input, consisting of output from the granular layer (approximately 25 ms), exogenous input to the supragranular layers (approximately 70 ms), and a second wave of granular output (approximately 135 ms). The model also predicted that SI correlates of perception reflect stronger and shorter-latency supragranular and late granular drive during perceived trials. These findings strongly support the view that signatures of tactile detection are present in human SI and are mediated by local neural dynamics induced by lamina-specific synaptic drive. Furthermore, our model provides a biophysically realistic solution to the MEG signal and can predict the electrophysiological correlates of human perception.

  14. Novel Tactile Sensor Technology and Smart Tactile Sensing Systems: A Review.

    Science.gov (United States)

    Zou, Liang; Ge, Chang; Wang, Z Jane; Cretu, Edmond; Li, Xiaoou

    2017-11-17

    During the last decades, smart tactile sensing systems based on different sensing techniques have been developed due to their high potential in industry and biomedical engineering. However, smart tactile sensing technologies and systems are still in their infancy, as many technological and system issues remain unresolved and require strong interdisciplinary efforts to address them. This paper provides an overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities. The tactile sensing transduction and principles, fabrication and structures are also discussed with their merits and demerits. Finally, the challenges that tactile sensing technology needs to overcome are highlighted.

  15. Novel Tactile Sensor Technology and Smart Tactile Sensing Systems: A Review

    Directory of Open Access Journals (Sweden)

    Liang Zou

    2017-11-01

    Full Text Available During the last decades, smart tactile sensing systems based on different sensing techniques have been developed due to their high potential in industry and biomedical engineering. However, smart tactile sensing technologies and systems are still in their infancy, as many technological and system issues remain unresolved and require strong interdisciplinary efforts to address them. This paper provides an overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities. The tactile sensing transduction and principles, fabrication and structures are also discussed with their merits and demerits. Finally, the challenges that tactile sensing technology needs to overcome are highlighted.

  16. A Two-Ply Polymer-Based Flexible Tactile Sensor Sheet Using Electric Capacitance

    Directory of Open Access Journals (Sweden)

    Shijie Guo

    2014-01-01

    Full Text Available Traditional capacitive tactile sensor sheets usually have a three-layered structure, with a dielectric layer sandwiched by two electrode layers. Each electrode layer has a number of parallel ribbon-like electrodes. The electrodes on the two electrode layers are oriented orthogonally and each crossing point of the two perpendicular electrode arrays makes up a capacitive sensor cell on the sheet. It is well known that compatibility between measuring precision and resolution is difficult, since decreasing the width of the electrodes is required to obtain a high resolution, however, this may lead to reduction of the area of the sensor cells, and as a result, lead to a low Signal/Noise (S/N ratio. To overcome this problem, a new multilayered structure and related calculation procedure are proposed. This new structure stacks two or more sensor sheets with shifts in position. Both a high precision and a high resolution can be obtained by combining the signals of the stacked sensor sheets. Trial production was made and the effect was confirmed.

  17. Smartphone-based tactile cueing improves motor performance in Parkinson's disease.

    Science.gov (United States)

    Ivkovic, Vladimir; Fisher, Stanley; Paloski, William H

    2016-01-01

    Visual and auditory cueing improve functional performance in Parkinson's disease (PD) patients. However, audiovisual processing shares many cognitive resources used for attention-dependent tasks such as communication, spatial orientation, and balance. Conversely, tactile cues (TC) may be processed faster, with minimal attentional demand, and may be more efficient means for modulating motor-cognitive performance. In this study we aimed to investigate the efficacy and limitations of TC for modulating simple (heel tapping) and more complex (walking) motor tasks (1) over a range of cueing intervals, (2) with/without a secondary motor task (holding tray with cups of water). Ten PD patients (71 ± 9 years) and 10 healthy controls (69 ± 7 years) participated in the study. TCs was delivered through a smart phone attached to subjects' dominant arm and were controlled by a custom-developed Android application. PD patients and healthy controls were able to use TC to modulate heel tapping (F(3.8,1866.1) = 1008.1, p usage for movement modulation and motor-cognitive integration in PD patients. The smartphone TC application was validated as a user-friendly movement modulation aid. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. A three-axis high-resolution capacitive tactile imager system based on floating comb electrodes

    International Nuclear Information System (INIS)

    Surapaneni, R; Guo, Q; Xie, Y; Young, D J; Mastrangelo, C H

    2013-01-01

    We present the design, fabrication and testing of a high-resolution 169-sensing cell capacitive flexible tactile imager (FTI) for normal and shear stress measurement as an auxiliary sensor for robotic grippers and gait analysis. The FTI consists of a flexible high-density array of normal stress and two-dimensional shear stress sensors fabricated using microelectromechanical systems (MEMS) and flexible printed circuit board (FPCB) techniques. The drive/sense lines of the FTI are realized using FPCB whereas the floating electrodes (Au) are patterned on a compressible PDMS layer spin coated on the FPCB layer. The use of unconnected floating electrodes significantly improves the reliability of traditional quad-electrode contact sensing devices by eliminating the need for patterning electrical wiring on PDMS. When placed at the heel of a boot, this FTI senses the position and motion of the line of contact with the ground. Normal stress readouts are obtained from the net capacitance of the cell and the shear-sense direction is determined by the amount of asymmetric overlap of the floating combs with respect to the bottom electrodes. The FTI is characterized using a high-speed switched-capacitor circuit with a 12-bit resolution at full frame rates of 100 Hz (∼0.8 Mb s −1 ) capable of resolving a displacement as low as 60 µm. The FTI and the readout circuitry contribute to a noise/interference level of 5 mV and the sensitivity of normal and shear stress for the FTI is 0.38 MPa −1 and 79.5 GPa −1 respectively. (paper)

  19. Age-related loss in attention-based modulation of tactile stimuli at early stages of somatosensory processing.

    Science.gov (United States)

    Bolton, David A E; Staines, W Richard

    2012-06-01

    Normal aging has been linked to impairments in gating of irrelevant sensory information and neural markers of diminished cognitive processing. Whilst much of the research in this area has focussed on visual and auditory modalities it is unclear to what degree these findings apply to somatosensation. Therefore we investigated how age impacts early event-related potentials (ERPs) arising from relevant or irrelevant vibrotactile stimuli to the fingertips. Specifically, we hypothesised that older adults would demonstrate reduced attention-based modulation of tactile ERPs generated at early stages of cortical somatosensory processing. In accord with previous research we also expected to observe diminished P300 responses to attended targets and behavioural deficits. Participants received vibrotactile stimulation to the second and fifth digit on the left hand and reported target stimuli on one digit only (as instructed) with comparisons between two age groups: (1) Young adults (age range 20-39) and (2) Older adults (age range 62-89). ERP amplitudes for the P50, N70, P100, N140 and long latency positivity (LLP) were quantified for attended and non-attended trials at several electrodes (C4, CP4, CP3 and FC4). The P300 in response to attended target stimuli was measured at CPZ. There was no effect of attention on the P50 and N70 however the P100, N140 and LLP were modulated with attention. In both age groups the P100 and LLP were more positive during trials where the stimuli were attended to, whilst the N140 was enhanced for non-attended stimuli. Comparisons between groups revealed a reduction in P100 attention-based modulation for the older adults versus the young adults. This effect was due to a loss of suppression of the non-attended stimuli in older subjects. Moreover, the P300 was both slower and reduced in peak amplitude for older subjects in response to attended targets. Finally, older adults demonstrated impaired performance in terms of both reduced target detection

  20. Parameter estimation of brain tumors using intraoperative thermal imaging based on artificial tactile sensing in conjunction with artificial neural network

    Science.gov (United States)

    Sadeghi-Goughari, M.; Mojra, A.; Sadeghi, S.

    2016-02-01

    Intraoperative Thermal Imaging (ITI) is a new minimally invasive diagnosis technique that can potentially locate margins of brain tumor in order to achieve maximum tumor resection with least morbidity. This study introduces a new approach to ITI based on artificial tactile sensing (ATS) technology in conjunction with artificial neural networks (ANN) and feasibility and applicability of this method in diagnosis and localization of brain tumors is investigated. In order to analyze validity and reliability of the proposed method, two simulations were performed. (i) An in vitro experimental setup was designed and fabricated using a resistance heater embedded in agar tissue phantom in order to simulate heat generation by a tumor in the brain tissue; and (ii) A case report patient with parafalcine meningioma was presented to simulate ITI in the neurosurgical procedure. In the case report, both brain and tumor geometries were constructed from MRI data and tumor temperature and depth of location were estimated. For experimental tests, a novel assisted surgery robot was developed to palpate the tissue phantom surface to measure temperature variations and ANN was trained to estimate the simulated tumor’s power and depth. Results affirm that ITI based ATS is a non-invasive method which can be useful to detect, localize and characterize brain tumors.

  1. Parameter estimation of brain tumors using intraoperative thermal imaging based on artificial tactile sensing in conjunction with artificial neural network

    International Nuclear Information System (INIS)

    Sadeghi-Goughari, M; Mojra, A; Sadeghi, S

    2016-01-01

    Intraoperative Thermal Imaging (ITI) is a new minimally invasive diagnosis technique that can potentially locate margins of brain tumor in order to achieve maximum tumor resection with least morbidity. This study introduces a new approach to ITI based on artificial tactile sensing (ATS) technology in conjunction with artificial neural networks (ANN) and feasibility and applicability of this method in diagnosis and localization of brain tumors is investigated. In order to analyze validity and reliability of the proposed method, two simulations were performed. (i) An in vitro experimental setup was designed and fabricated using a resistance heater embedded in agar tissue phantom in order to simulate heat generation by a tumor in the brain tissue; and (ii) A case report patient with parafalcine meningioma was presented to simulate ITI in the neurosurgical procedure. In the case report, both brain and tumor geometries were constructed from MRI data and tumor temperature and depth of location were estimated. For experimental tests, a novel assisted surgery robot was developed to palpate the tissue phantom surface to measure temperature variations and ANN was trained to estimate the simulated tumor’s power and depth. Results affirm that ITI based ATS is a non-invasive method which can be useful to detect, localize and characterize brain tumors. (paper)

  2. Development of flexible array tactile sensors

    DEFF Research Database (Denmark)

    Drimus, Alin; Marian, Nicolae; Bilberg, Arne

    2010-01-01

    In this paper we describe the development of an array tactile sensor for use in robotic grippers based on a flexible piezoresistive material. We start by comparing different cell structures in terms of output characteristics and we construct an array of cells in a row and columns layout. A real...... time data acquisition system scans all the cells and converts electrical resistance to tactile pressure maps. We validate that this information can be used to improve grasping and perform object recognition. Key words: piezoresistivity, tactile, sensor, pressure, robotics...

  3. Feedforward Neural Network for Force Coding of an MRI-Compatible Tactile Sensor Array Based on Fiber Bragg Grating

    Directory of Open Access Journals (Sweden)

    Paola Saccomandi

    2015-01-01

    Full Text Available This work shows the development and characterization of a fiber optic tactile sensor based on Fiber Bragg Grating (FBG technology. The sensor is a 3 × 3 array of FBGs encapsulated in a PDMS compliant polymer. The strain experienced by each FBG is transduced into a Bragg wavelength shift and the inverse characteristics of the sensor were computed by means of a feedforward neural network. A 21 mN RMSE error was achieved in estimating the force over the 8 N experimented load range while including all probing sites in the neural network training procedure, whereas the median force RMSE was 199 mN across the 200 instances of a Monte Carlo randomized selection of experimental sessions to evaluate the calibration under generalized probing conditions. The static metrological properties and the possibility to fabricate sensors with relatively high spatial resolution make the proposed design attractive for the sensorization of robotic hands. Furthermore, the proved MRI-compatibility of the sensor opens other application scenarios, such as the possibility to employ the array for force measurement during functional MRI-measured brain activation.

  4. An overview of tactile sensing

    Science.gov (United States)

    Agrawal, Rajeev; Jain, Ramesh

    1986-01-01

    Existing or proposed tactile sensors are reviewed. General considerations involved in tactile sensing and various performance criteria are discussed. Typical specifications to be expected from the sensors are also described. A representative set of present day tactile sensors is studied. Finally, some of the proposed recognition systems using tactile sensing are described.

  5. Condition Assessment of Foundation Piles and Utility Poles Based on Guided Wave Propagation Using a Network of Tactile Transducers and Support Vector Machines.

    Science.gov (United States)

    Dackermann, Ulrike; Yu, Yang; Niederleithinger, Ernst; Li, Jianchun; Wiggenhauser, Herbert

    2017-12-18

    This paper presents a novel non-destructive testing and health monitoring system using a network of tactile transducers and accelerometers for the condition assessment and damage classification of foundation piles and utility poles. While in traditional pile integrity testing an impact hammer with broadband frequency excitation is typically used, the proposed testing system utilizes an innovative excitation system based on a network of tactile transducers to induce controlled narrow-band frequency stress waves. Thereby, the simultaneous excitation of multiple stress wave types and modes is avoided (or at least reduced), and targeted wave forms can be generated. The new testing system enables the testing and monitoring of foundation piles and utility poles where the top is inaccessible, making the new testing system suitable, for example, for the condition assessment of pile structures with obstructed heads and of poles with live wires. For system validation, the new system was experimentally tested on nine timber and concrete poles that were inflicted with several types of damage. The tactile transducers were excited with continuous sine wave signals of 1 kHz frequency. Support vector machines were employed together with advanced signal processing algorithms to distinguish recorded stress wave signals from pole structures with different types of damage. The results show that using fast Fourier transform signals, combined with principal component analysis as the input feature vector for support vector machine (SVM) classifiers with different kernel functions, can achieve damage classification with accuracies of 92.5% ± 7.5%.

  6. Condition Assessment of Foundation Piles and Utility Poles Based on Guided Wave Propagation Using a Network of Tactile Transducers and Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Ulrike Dackermann

    2017-12-01

    Full Text Available This paper presents a novel non-destructive testing and health monitoring system using a network of tactile transducers and accelerometers for the condition assessment and damage classification of foundation piles and utility poles. While in traditional pile integrity testing an impact hammer with broadband frequency excitation is typically used, the proposed testing system utilizes an innovative excitation system based on a network of tactile transducers to induce controlled narrow-band frequency stress waves. Thereby, the simultaneous excitation of multiple stress wave types and modes is avoided (or at least reduced, and targeted wave forms can be generated. The new testing system enables the testing and monitoring of foundation piles and utility poles where the top is inaccessible, making the new testing system suitable, for example, for the condition assessment of pile structures with obstructed heads and of poles with live wires. For system validation, the new system was experimentally tested on nine timber and concrete poles that were inflicted with several types of damage. The tactile transducers were excited with continuous sine wave signals of 1 kHz frequency. Support vector machines were employed together with advanced signal processing algorithms to distinguish recorded stress wave signals from pole structures with different types of damage. The results show that using fast Fourier transform signals, combined with principal component analysis as the input feature vector for support vector machine (SVM classifiers with different kernel functions, can achieve damage classification with accuracies of 92.5% ± 7.5%.

  7. Instrumental tactile diagnostics in robot-assisted surgery

    Directory of Open Access Journals (Sweden)

    Solodova RF

    2016-10-01

    boundaries were not visually detectable, instrumental tactile diagnostics performed using MTEC provided valid identification and localization of lesions. The results of instrumental tactile diagnostics were concordant with the results of intraoperative ultrasound examination. However, in certain cases, for example, thoracoscopy, ultrasound examination is inapplicable, while MTEC-based tactile diagnostics can be efficiently utilized. Conclusion: The study proved that MTEC can be efficiently used in robot-assisted surgery allowing correct localization of visually undetectable lesions and visually undetectable boundaries of pathological changes of tissues. Keywords: tactile feedback, instrumental palpation, Medical Tactile Endosurgical Complex, tactile lesion localization

  8. Piezoresistive Tactile Sensor Discriminating Multidirectional Forces

    Directory of Open Access Journals (Sweden)

    Youngdo Jung

    2015-10-01

    Full Text Available Flexible tactile sensors capable of detecting the magnitude and direction of the applied force together are of great interest for application in human-interactive robots, prosthetics, and bionic arms/feet. Human skin contains excellent tactile sensing elements, mechanoreceptors, which detect their assigned tactile stimuli and transduce them into electrical signals. The transduced signals are transmitted through separated nerve fibers to the central nerve system without complicated signal processing. Inspired by the function and organization of human skin, we present a piezoresistive type tactile sensor capable of discriminating the direction and magnitude of stimulations without further signal processing. Our tactile sensor is based on a flexible core and four sidewall structures of elastomer, where highly sensitive interlocking piezoresistive type sensing elements are embedded. We demonstrate the discriminating normal pressure and shear force simultaneously without interference between the applied forces. The developed sensor can detect down to 128 Pa in normal pressure and 0.08 N in shear force, respectively. The developed sensor can be applied in the prosthetic arms requiring the restoration of tactile sensation to discriminate the feeling of normal and shear force like human skin.

  9. Bioinspired electronic white cane implementation based on a LIDAR, a tri-axial accelerometer and a tactile belt.

    Science.gov (United States)

    Pallejà, Tomàs; Tresanchez, Marcel; Teixidó, Mercè; Palacin, Jordi

    2010-01-01

    This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user's forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment.

  10. Bioinspired Electronic White Cane Implementation Based on a LIDAR, a Tri-Axial Accelerometer and a Tactile Belt

    Directory of Open Access Journals (Sweden)

    Jordi Palacin

    2010-12-01

    Full Text Available This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user’s forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment.

  11. Tactile mental body parts representation in obesity.

    Science.gov (United States)

    Scarpina, Federica; Castelnuovo, Gianluca; Molinari, Enrico

    2014-12-30

    Obese people׳s distortions in visually-based mental body-parts representations have been reported in previous studies, but other sensory modalities have largely been neglected. In the present study, we investigated possible differences in tactilely-based body-parts representation between an obese and a healthy-weight group; additionally we explore the possible relationship between the tactile- and the visually-based body representation. Participants were asked to estimate the distance between two tactile stimuli that were simultaneously administered on the arm or on the abdomen, in the absence of visual input. The visually-based body-parts representation was investigated by a visual imagery method in which subjects were instructed to compare the horizontal extension of body part pairs. According to the results, the obese participants overestimated the size of the tactilely-perceived distances more than the healthy-weight group when the arm, and not the abdomen, was stimulated. Moreover, they reported a lower level of accuracy than did the healthy-weight group when estimating horizontal distances relative to their bodies, confirming an inappropriate visually-based mental body representation. Our results imply that body representation disturbance in obese people is not limited to the visual mental domain, but it spreads to the tactilely perceived distances. The inaccuracy was not a generalized tendency but was body-part related. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Towards the Tactile Internet

    DEFF Research Database (Denmark)

    Szabó, Dávid; Gulyás, András; Fitzek, Frank

    2015-01-01

    5G communication networks enable the steering and control of Internet of Things and therefore require extreme low latency communication referred to as the tactile Internet. In this paper we show that the massive use of network coding throughout the network significantly improves latency and reduce...... the frequency of packet re-transmission, so an architecture built around network coding may be a feasible road towards realizing the tactile internet vision. Our contribution is threefold: (i) we show how network coding improves latency and reduces packet re-transmission with respect to other coding schemes...

  13. A Case Study of Tactile Language and its Possible Structure

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup; Nielsen, Anja; Strøm, Emilie

    2015-01-01

    of a five year old congenital deafblind child communicating with his mother about a slide experience tactile linguistic features of phonology, morphology, semantics and syntax were explored. The linguistic features of tactile language were found to involve a potential unique and complex structure based...

  14. Capacitive wearable tactile sensor based on smart textile substrate with carbon black /silicone rubber composite dielectric

    Science.gov (United States)

    Guo, Xiaohui; Huang, Ying; Cai, Xia; Liu, Caixia; Liu, Ping

    2016-04-01

    To achieve the wearable comfort of electronic skin (e-skin), a capacitive sensor printed on a flexible textile substrate with a carbon black (CB)/silicone rubber (SR) composite dielectric was demonstrated in this paper. Organo-silicone conductive silver adhesive serves as a flexible electrodes/shielding layer. The structure design, sensing mechanism and the influence of the conductive filler content and temperature variations on the sensor performance were investigated. The proposed device can effectively enhance the flexibility and comfort of wearing the device asthe sensing element has achieved a sensitivity of 0.02536%/KPa, a hysteresis error of 5.6%, and a dynamic response time of ~89 ms at the range of 0-700 KPa. The drift induced by temperature variations has been calibrated by presenting the temperature compensation model. The research on the time-space distribution of plantar pressure information and the experiment of the manipulator soft-grasping were implemented with the introduced device, and the experimental results indicate that the capacitive flexible textile tactile sensor has good stability and tactile perception capacity. This study provides a good candidate for wearable artificial skin.

  15. Novel high resolution tactile robotic fingertips

    DEFF Research Database (Denmark)

    Drimus, Alin; Jankovics, Vince; Gorsic, Matija

    2014-01-01

    This paper describes a novel robotic fingertip based on piezoresistive rubber that can sense pressure tactile stimuli with a high spatial resolution over curved surfaces. The working principle is based on a three-layer sandwich structure (conductive electrodes on top and bottom and piezoresistive...

  16. A Case Study of Tactile Language and its Possible Structure

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup; Nielsen, Anja; Strøm, Emilie

    2015-01-01

    Few published research papers concern the study of communication and language development among children with congenital deafblindness. The aim of this study is to explore and discuss linguistic features of what may be considered as tactile languages. By analysing one pilot video observation...... of a five year old congenital deafblind child communicating with his mother about a slide experience tactile linguistic features of phonology, morphology, semantics and syntax were explored. The linguistic features of tactile language were found to involve a potential unique and complex structure based...... on direction, speed and acceleration of movements, pressure, and body position. It is discussed how tactile languages, if they exist, can be studied from its unique bodily-tactile nature and not as a modification of visual sign languages....

  17. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  18. Cooperative processing in primary somatosensory cortex and posterior parietal cortex during tactile working memory.

    Science.gov (United States)

    Ku, Yixuan; Zhao, Di; Bodner, Mark; Zhou, Yong-Di

    2015-08-01

    In the present study, causal roles of both the primary somatosensory cortex (SI) and the posterior parietal cortex (PPC) were investigated in a tactile unimodal working memory (WM) task. Individual magnetic resonance imaging-based single-pulse transcranial magnetic stimulation (spTMS) was applied, respectively, to the left SI (ipsilateral to tactile stimuli), right SI (contralateral to tactile stimuli) and right PPC (contralateral to tactile stimuli), while human participants were performing a tactile-tactile unimodal delayed matching-to-sample task. The time points of spTMS were 300, 600 and 900 ms after the onset of the tactile sample stimulus (duration: 200 ms). Compared with ipsilateral SI, application of spTMS over either contralateral SI or contralateral PPC at those time points significantly impaired the accuracy of task performance. Meanwhile, the deterioration in accuracy did not vary with the stimulating time points. Together, these results indicate that the tactile information is processed cooperatively by SI and PPC in the same hemisphere, starting from the early delay of the tactile unimodal WM task. This pattern of processing of tactile information is different from the pattern in tactile-visual cross-modal WM. In a tactile-visual cross-modal WM task, SI and PPC contribute to the processing sequentially, suggesting a process of sensory information transfer during the early delay between modalities. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  19. Footwear discrimination using dynamic tactile information

    DEFF Research Database (Denmark)

    Drimus, Alin; Mikov, Vedran

    2017-01-01

    Abstract: This paper shows that it is possible to differentiate among various type of footwear solely by using highly dimensional pressure information provided by a sensorised insole. In order to achieve this, a person equipped with two sensorised insoles streaming real-time tactile data to a com......Abstract: This paper shows that it is possible to differentiate among various type of footwear solely by using highly dimensional pressure information provided by a sensorised insole. In order to achieve this, a person equipped with two sensorised insoles streaming real-time tactile data...... to a computer performs normal walking patterns. The sampled data is further transformed and reduced to sets of time series which are used for the classification of footwear. The pressure sensor is formed as a footwear inlay and is based on piezoresistive rubber having 1024 tactile cells providing normal...... pressure information in the form of a tactile image. The data is transmitted in realtime wirelessly at 30 fps from two such sensors. The online classification is using the dynamic time warping distances for different extracted features to assess the most similar type of footwear based on time series...

  20. Development of flexible tactile sensors for hexapod robots

    DEFF Research Database (Denmark)

    Drimus, Alin; Børlum-Petersen, Mikkel; Jouffroy, Jerome

    2013-01-01

    This paper describes the development of flexible based tactile array sensors based on piezoresistive rubber for use in the leg tips of hexapod robotics. The sensors are composed of a sandwich similar structure, with a piezoresistive rubber used as the middle layer and flexPCB electrodes on the up......This paper describes the development of flexible based tactile array sensors based on piezoresistive rubber for use in the leg tips of hexapod robotics. The sensors are composed of a sandwich similar structure, with a piezoresistive rubber used as the middle layer and flexPCB electrodes...... on the upper and lower part of the rubber. To address a wider range of tactile stimuli, namely the dynamic tactile stimuli, a piezoelectric thin film sensor based on polyvinylidene fluoride(PVDF) is embedded into the leg tip mould. Both piezoresistive array and piezoelectric types of sensors are investigated...

  1. Tactile Astronomy - a Portuguese case study

    Science.gov (United States)

    Canas, L.; Alves, F.; Correia, A.

    2012-09-01

    Although astronomy plays an important role in the most various outreach initiatives, as well as school science curricula, due to its strong visual component in knowledge acquisition, astronomy subjects are not entirely well addressed and accessed by visually impaired students and/or general public. This stresses the need of more tactile material production, still very scarce in an educational context whether formal or informal. This is a case study activity developed based on different schematic tactile images of several objects present in our solar system. These images in relief, highlight, through touch, several relevant features present in the different astronomical objects studied. The scientific knowledge is apprehended through the use of a tactile key, complemented with additional information. Through proper hands-on activities implementation and careful analysis of the outcome, the adapted images associated with an explanatory key prove to be a valuable resource in tactile astronomy domain. Here we describe the process of implementing such initiative near visually impaired students. The struggles and challenges perceived by all involved and the enrichment experience of engaging astronomy with visually impaired audiences, broadening horizons in an overall experience accessible to all.

  2. Mechanisms of tactile sensory deterioration amongst the elderly.

    Science.gov (United States)

    Skedung, Lisa; El Rawadi, Charles; Arvidsson, Martin; Farcet, Céline; Luengo, Gustavo S; Breton, Lionel; Rutland, Mark W

    2018-04-19

    It is known that roughness-smoothness, hardness-softness, stickiness-slipperiness and warm-cold are predominant perceptual dimensions in macro-, micro- and nano- texture perception. However, it is not clear to what extent active tactile texture discrimination remains intact with age. The general decrease in tactile ability induces physical and emotional dysfunction in elderly, and has increasing significance for an aging population. We report a method to quantify tactile acuity based on blinded active exploration of systematically varying micro-textured surfaces and a same-different paradigm. It reveals that elderly participants show significantly reduced fine texture discrimination ability. The elderly group also displays statistically lower finger friction coefficient, moisture and elasticity, suggesting a link. However, a subpopulation of the elderly retains discrimination ability irrespective of cutaneous condition and this can be related to a higher density of somatosensory receptors on the finger pads. Skin tribology is thus not the primary reason for decline of tactile discrimination with age. The remediation of cutaneous properties through rehydration, however leads to a significantly improved tactile acuity. This indicates unambiguously that neurological tactile loss can be temporarily compensated by restoring the cutaneous contact mechanics. Such mechanical restoration of tactile ability has the potential to increase the quality of life in elderly.

  3. Bodily illusions disrupt tactile sensations.

    Science.gov (United States)

    D'Amour, Sarah; Pritchett, Lisa M; Harris, Laurence R

    2015-02-01

    To accurately interpret tactile information, the brain needs to have an accurate representation of the body to which to refer the sensations. Despite this, body representation has only recently been incorporated into the study of tactile perception. Here, we investigate whether distortions of body representation affect tactile sensations. We perceptually altered the length of the arm and the width of the waist using a tendon vibration illusion and measured spatial acuity and sensitivity. Surprisingly, we found reduction in both tactile acuity and sensitivity thresholds when the arm or waist was perceptually altered, which indicates a general disruption of low-level tactile processing. We postulate that the disruptive changes correspond to the preliminary stage as the body representation starts to change and may give new insights into sensory processing in people with long-term or sudden abnormal body representation such as are found in eating disorders or following amputation.

  4. Bayesian Alternation During Tactile Augmentation

    Directory of Open Access Journals (Sweden)

    Caspar Mathias Goeke

    2016-10-01

    Full Text Available A large number of studies suggest that the integration of multisensory signals by humans is well described by Bayesian principles. However, there are very few reports about cue combination between a native and an augmented sense. In particular, we asked the question whether adult participants are able to integrate an augmented sensory cue with existing native sensory information. Hence for the purpose of this study we build a tactile augmentation device. Consequently, we compared different hypotheses of how untrained adult participants combine information from a native and an augmented sense. In a two-interval forced choice (2 IFC task, while subjects were blindfolded and seated on a rotating platform, our sensory augmentation device translated information on whole body yaw rotation to tactile stimulation. Three conditions were realized: tactile stimulation only (augmented condition, rotation only (native condition, and both augmented and native information (bimodal condition. Participants had to choose one out of two consecutive rotations with higher angular rotation. For the analysis, we fitted the participants’ responses with a probit model and calculated the just notable difference (JND. Then we compared several models for predicting bimodal from unimodal responses. An objective Bayesian alternation model yielded a better prediction (χred2 = 1.67 than the Bayesian integration model (χred2= 4.34. Slightly higher accuracy showed a non-Bayesian winner takes all model (χred2= 1.64, which either used only native or only augmented values per subject for prediction. However the performance of the Bayesian alternation model could be substantially improved (χred2= 1.09 utilizing subjective weights obtained by a questionnaire. As a result, the subjective Bayesian alternation model predicted bimodal performance most accurately among all tested models. These results suggest that information from augmented and existing sensory modalities in

  5. Tactile score a knowledge media for tactile sense

    CERN Document Server

    Suzuki, Yasuhiro

    2014-01-01

    This book deals with one of the most novel advances in natural computing, namely, in the field of tactile sense analysis. Massage, which provides relaxation and stimulation for human beings, is analyzed in this book for the first time by encoding the motions and tactile senses involved. The target audience is not limited to researchers who are interested in natural computing but also includes those working in ergonomic design, biomedical engineering, Kansei engineering, and cognitive science.

  6. Differential effects of synchronous and asynchronous multifinger coactivation on human tactile performance

    Directory of Open Access Journals (Sweden)

    Dinse Hubert R

    2007-07-01

    Full Text Available Abstract Background Repeated execution of a tactile task enhances task performance. In the present study we sought to improve tactile performance with unattended activation-based learning processes (i.e., focused stimulation of dermal receptors evoking neural coactivation (CA. Previous studies show that the application of CA to a single finger reduced the stationary two-point discrimination threshold and significantly increased tactile acuity. These changes were accompanied by an expansion of the cortical finger representation in primary somatosensory cortex (SI. Here we investigated the effect of different types of multifinger CA on the tactile performance of each finger of the right hand. Results Synchronous and asynchronous CA was applied to all fingers of a subject's dominant hand. We evaluated changes in absolute touch thresholds, static two-point discrimination thresholds, and mislocalization of tactile stimuli to the fingertips. After synchronous CA, tactile acuity improved (i.e., discrimination thresholds decreased and the frequency of mislocalization of tactile stimuli changed from directly neighboring fingers to more distant fingers. On the other hand, asynchronous CA did not significant improve tactile acuity. In fact, there was evidence of impaired tactile acuity. Multifinger CA with synchronous or asynchronous stimulation did not significantly alter absolute touch thresholds. Conclusion Our results demonstrate that it is possible to extend tactile CA to all fingers of a hand. The observed changes in mislocalization of tactile stimuli after synchronous CA indicate changes in the topography of the cortical hand representation. Although single-finger CA has been shown to improve tactile acuity, asynchronous CA of all fingers of the hand had the opposite effect, suggesting the need for synchrony in multifinger CA for improving tactile acuity.

  7. Osseoperception: active tactile sensibility of osseointegrated dental implants.

    Science.gov (United States)

    Enkling, Norbert; Utz, Karl Heinz; Bayer, Stefan; Stern, Regina Mericske

    2010-01-01

    The phenomenon of developing a certain tactile sensibility through osseointegrated dental implants is called osseoperception. Active tactile sensibility can be tested by having the subject bite on test bodies. The aim of the study was to describe the active tactile sensibility of single-tooth implants based on the 50% value and the slope of the sensibility curve at the 50% value. Sixty-two subjects with single-tooth implants with natural opposing teeth were included in the study. In a computer-assisted and randomized way, copper foils of varying thickness (0 to 200 Μm) were placed inter?occlusally between the single-tooth implant and the natural opposing tooth, and the active tactile perception was studied according to the psychophysical method of constant stimuli and statistically evaluated by logistic regression. Tactile perception of the implants at the 50% value estimated by logistic regression was 20.2 ± 10.9 Μm on average, and the slope was 29 ± 15. Regarding implant surface structure, significant differences were observed. The sandblasted and acid-etched surface was significantly more sensitive than the titanium plasma-sprayed surface, and the machined surface was similar to the titanium plasma-sprayed surface. Active tactile sensibility of implants with natural antagonistic teeth is very similar to that of teeth, but the slope of the tactile sensibility curve is flatter. Significant differences in tactile sensibility as a function of different implant surfaces may indicate that receptors near the implant form the basis of osseoperception.

  8. Computational Intelligence Techniques for Tactile Sensing Systems

    Science.gov (United States)

    Gastaldo, Paolo; Pinna, Luigi; Seminara, Lucia; Valle, Maurizio; Zunino, Rodolfo

    2014-01-01

    Tactile sensing helps robots interact with humans and objects effectively in real environments. Piezoelectric polymer sensors provide the functional building blocks of the robotic electronic skin, mainly thanks to their flexibility and suitability for detecting dynamic contact events and for recognizing the touch modality. The paper focuses on the ability of tactile sensing systems to support the challenging recognition of certain qualities/modalities of touch. The research applies novel computational intelligence techniques and a tensor-based approach for the classification of touch modalities; its main results consist in providing a procedure to enhance system generalization ability and architecture for multi-class recognition applications. An experimental campaign involving 70 participants using three different modalities in touching the upper surface of the sensor array was conducted, and confirmed the validity of the approach. PMID:24949646

  9. Computational intelligence techniques for tactile sensing systems.

    Science.gov (United States)

    Gastaldo, Paolo; Pinna, Luigi; Seminara, Lucia; Valle, Maurizio; Zunino, Rodolfo

    2014-06-19

    Tactile sensing helps robots interact with humans and objects effectively in real environments. Piezoelectric polymer sensors provide the functional building blocks of the robotic electronic skin, mainly thanks to their flexibility and suitability for detecting dynamic contact events and for recognizing the touch modality. The paper focuses on the ability of tactile sensing systems to support the challenging recognition of certain qualities/modalities of touch. The research applies novel computational intelligence techniques and a tensor-based approach for the classification of touch modalities; its main results consist in providing a procedure to enhance system generalization ability and architecture for multi-class recognition applications. An experimental campaign involving 70 participants using three different modalities in touching the upper surface of the sensor array was conducted, and confirmed the validity of the approach.

  10. Computational Intelligence Techniques for Tactile Sensing Systems

    Directory of Open Access Journals (Sweden)

    Paolo Gastaldo

    2014-06-01

    Full Text Available Tactile sensing helps robots interact with humans and objects effectively in real environments. Piezoelectric polymer sensors provide the functional building blocks of the robotic electronic skin, mainly thanks to their flexibility and suitability for detecting dynamic contact events and for recognizing the touch modality. The paper focuses on the ability of tactile sensing systems to support the challenging recognition of certain qualities/modalities of touch. The research applies novel computational intelligence techniques and a tensor-based approach for the classification of touch modalities; its main results consist in providing a procedure to enhance system generalization ability and architecture for multi-class recognition applications. An experimental campaign involving 70 participants using three different modalities in touching the upper surface of the sensor array was conducted, and confirmed the validity of the approach.

  11. Intuitive tactile algorithms to guide blind runners by means of a belt with vibrators.

    Science.gov (United States)

    Durá-Gil, Juan V; Bazuelo-Ruiz, Bruno; Mollà, Fernando; Barberà-Guillem, Ricard; Jakab, Àgnes; Csielka, Tamás

    2015-01-01

    Visually impaired people do not have equal possibilities to practice sports. In the case of running they need a sighted guide. This paper compare different possibilities for indicating direction to blind people by means of a belt that transmits tactile messages, and defines design requirements based on anthropometric analysis. The results shows that intuitive tactile messages are achieved with tactile stimuli applied in the ventral section, from the iliac crests to the navel.

  12. Tactile device utilizing a single magnetorheological sponge: experimental investigation

    Science.gov (United States)

    Kim, Soomin; Kim, Pyunghwa; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.

  13. Contralateral tactile masking between forearms.

    Science.gov (United States)

    D'Amour, Sarah; Harris, Laurence R

    2014-03-01

    Masking effects have been demonstrated in which tactile sensitivity is affected when one touch is close to another on the body surface. Such effects are likely a result of local lateral inhibitory circuits that sharpen the spatial tuning of a given tactile receptor. Mutually inhibitory pathways have also been demonstrated between cortical tactile maps of the two halves of the body. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at contralateral locations. Here, we measure the spatial tuning and effect of posture on this contralateral masking effect. Tactile sensitivity was measured on one forearm, while vibrotactile masking stimulation was applied to the opposite arm. Results were compared to sensitivity while vibrotactile stimulation was applied to a control site on the right shoulder. Sensitivity on the forearm was reduced by over 3 dB when the arms were touching and by 0.52 dB when they were held parallel. The masking effect depended on the position of the masking stimulus. Its effectiveness fell off by 1 STD when the stimulus was 29 % of arm length from the corresponding contralateral point. This long-range inhibitory effect in the tactile system suggests a surprisingly intimate relationship between the two sides of the body.

  14. Virtual environment tactile system

    Science.gov (United States)

    Renzi, Ronald

    1996-01-01

    A method for providing a realistic sense of touch in virtual reality by means of programmable actuator assemblies is disclosed. Each tactile actuator assembly consists of a number of individual actuators whose movement is controlled by a computer and associated drive electronics. When an actuator is energized, the rare earth magnet and the associated contactor, incorporated within the actuator, are set in motion by the opposing electromagnetic field of a surrounding coil. The magnet pushes the contactor forward to contact the skin resulting in the sensation of touch. When the electromagnetic field is turned off, the rare earth magnet and the contactor return to their neutral positions due to the magnetic equilibrium caused by the interaction with the ferrous outer sleeve. The small size and flexible nature of the actuator assemblies permit incorporation into a glove, boot or body suit. The actuator has additional applications, such as, for example, as an accelerometer, an actuator for precisely controlled actuations or to simulate the sensation of braille letters.

  15. Tactile Modulation of Emotional Speech Samples

    Directory of Open Access Journals (Sweden)

    Katri Salminen

    2012-01-01

    Full Text Available Traditionally only speech communicates emotions via mobile phone. However, in daily communication the sense of touch mediates emotional information during conversation. The present aim was to study if tactile stimulation affects emotional ratings of speech when measured with scales of pleasantness, arousal, approachability, and dominance. In the Experiment 1 participants rated speech-only and speech-tactile stimuli. The tactile signal mimicked the amplitude changes of the speech. In the Experiment 2 the aim was to study whether the way the tactile signal was produced affected the ratings. The tactile signal either mimicked the amplitude changes of the speech sample in question, or the amplitude changes of another speech sample. Also, concurrent static vibration was included. The results showed that the speech-tactile stimuli were rated as more arousing and dominant than the speech-only stimuli. The speech-only stimuli were rated as more approachable than the speech-tactile stimuli, but only in the Experiment 1. Variations in tactile stimulation also affected the ratings. When the tactile stimulation was static vibration the speech-tactile stimuli were rated as more arousing than when the concurrent tactile stimulation was mimicking speech samples. The results suggest that tactile stimulation offers new ways of modulating and enriching the interpretation of speech.

  16. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    the user’s perspective. Here we present the process of selecting the most adequate tactile stimulation delivered by a tactile vest while users were engaged in an absorbing activity, namely playing a video-game. A total of 20 participants (mean age 24.78; SD= 1.57) were involved. Among the eight tactile...

  17. Exploration of the Effectiveness of Tactile Methods

    Science.gov (United States)

    Aldajani, Neda F.

    2016-01-01

    This paper introduces the tactile method and aims to explore the effectiveness of using tactile methods with students who are blind and visually impaired. Although there was limited research about using this strategy, all of the research agrees that using tactile is one of the best ways for students who are blind and visually impaired to be…

  18. TACTILE SENSING FOR OBJECT IDENTIFICATION

    DEFF Research Database (Denmark)

    Drimus, Alin; Marian, Nicolae; Bilberg, Arne

    2009-01-01

    in unstructured environments, tactile sensing can provide more than valuable to complementary vision information about mechanical properties such as recognition and characterization, force, pressure, torque, compliance, friction, and mass as well as object shape, texture, position and pose. In this paper, we...... described the working principles of a few types of tactile sensing cells, focusing on the piezoresistive materials. Starting from a set of requirements for developing a high resolution flexible array sensor we have investigated if CSA pressure sensitive conductive rubber could be a proper candidate and can...

  19. A Comparison of Tactile Sensors for In-Hand Object Location

    Directory of Open Access Journals (Sweden)

    Raul Fernandez

    2016-01-01

    Full Text Available This work presents an extensive analysis of the usefulness of tactile sensors for in-hand object localization. Our analysis is based on a previous work where we proposed a method for the evaluation of tactile data using two algorithms: a Particle Filter algorithm and an Iterative Closest Point algorithm. In particular, we present a comparison of six different sensors, including two pairs of sensors based on similar technology, showing how the design and distribution of tactile sensors can affect the performance. Also, together with previous results where we demonstrated the importance of the synergy between tactile data and hand geometry, we corroborate that it is possible to obtain more similar performance with a simple fingertip sensor, than with more complex and expensive tactile sensors.

  20. A Prototype Tactile Sensor Array.

    Science.gov (United States)

    1982-09-15

    Active Touch Sensing. Technical Report, MIT Artificial Inteligence Laboratory, 1981. (9] Larcombe, M. Carbon Fibre Tactile Sensors. Technical Report...thesis, Carnegie-Mellon University, 1981. [13] Purbrick, John A. A Force Transducer Employing Conductive Silicone Rubber. Technical Report, MIT Artificial

  1. Magnetic Nanocomposite Cilia Tactile Sensor

    KAUST Repository

    Alfadhel, Ahmed

    2015-10-21

    A multifunctional biomimetic nanocomposite tactile sensor is developed that can detect shear and vertical forces, feel texture, and measure flow with extremely low power consumption. The sensor\\'s high performance is maintained within a wide operating range that can be easily adjusted. The concept works on rigid and flexible substrates and the sensors can be used in air or water without any modifications.

  2. Tactile thresholds in healthy subjects

    Directory of Open Access Journals (Sweden)

    Metka Moharić

    2014-10-01

    Full Text Available Background: The assessment of sensory thresholds provides a method of examining the function of peripheral nerve fibers and their central connections. Quantitative sensory testing is a variant of conventional sensory testing wherein the goal is the quantification of the level of stimulation needed to produce a particular sensation. While thermal and vibratory testing are established methods in assessment of sensory thresholds, assessment of tactile thresholds with monofilaments is not used routinely. The purpose of this study was to assess the tactile thresholds in normal healthy population.Methods: In 39 healthy volunteers (19 men aged 21 to 71 years, tactile thresholds were assessed with von Frey’s hair in 7 parts of the body bilaterally.Results: We found touch sensitivity not to be dependent on age or gender. The right side was significantly more sensitive in the lateral part of the leg (p=0.011 and the left side in the medial part of the arm (p=0.022. There were also significant differences between sites (p<0.001, whereby distal parts of the body were more sensitive.Conclusions: Von Frey filaments allow the estimation of tactile thresholds without the need for complicated instrumentation.

  3. Tactile friction of topical formulations.

    Science.gov (United States)

    Skedung, L; Buraczewska-Norin, I; Dawood, N; Rutland, M W; Ringstad, L

    2016-02-01

    The tactile perception is essential for all types of topical formulations (cosmetic, pharmaceutical, medical device) and the possibility to predict the sensorial response by using instrumental methods instead of sensory testing would save time and cost at an early stage product development. Here, we report on an instrumental evaluation method using tactile friction measurements to estimate perceptual attributes of topical formulations. Friction was measured between an index finger and an artificial skin substrate after application of formulations using a force sensor. Both model formulations of liquid crystalline phase structures with significantly different tactile properties, as well as commercial pharmaceutical moisturizing creams being more tactile-similar, were investigated. Friction coefficients were calculated as the ratio of the friction force to the applied load. The structures of the model formulations and phase transitions as a result of water evaporation were identified using optical microscopy. The friction device could distinguish friction coefficients between the phase structures, as well as the commercial creams after spreading and absorption into the substrate. In addition, phase transitions resulting in alterations in the feel of the formulations could be detected. A correlation was established between skin hydration and friction coefficient, where hydrated skin gave rise to higher friction. Also a link between skin smoothening and finger friction was established for the commercial moisturizing creams, although further investigations are needed to analyse this and correlations with other sensorial attributes in more detail. The present investigation shows that tactile friction measurements have potential as an alternative or complement in the evaluation of perception of topical formulations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Object texture recognition by dynamic tactile sensing using active exploration

    DEFF Research Database (Denmark)

    Drimus, Alin; Børlum Petersen, Mikkel; Bilberg, Arne

    For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a method for determining object texture by active exploration with a robotic fingertip equipped with a d......For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a method for determining object texture by active exploration with a robotic fingertip equipped...... with a dynamic tactile transducer based on polyvinylidene fluoride (PVDF) piezoelectric film. Different test surfaces are actively explored and the signal from the sensor is used for feature extraction, which is subsequently used for classification. A comparison between the significance of different extracted...

  5. Effect of Electrostatic Tactile Feedback on Accuracy and Efficiency of Pan Gestures on Touch Screens.

    Science.gov (United States)

    Liu, Guohong; Sun, Xiaoying; Wang, Dangxiao; Liu, Yue; Zhang, Yuru

    2018-01-01

    Recently, many studies examined electrostatic tactile feedback on touch screens to enrich interaction experience. However, it is unclear as to whether added tactile feedback during a sliding process increases the accuracy of pan gestures with velocity constraints. In this study, a custom-designed electrostatic tactile display was considered. Initially, the accuracy and efficiency of pan gestures were compared under two conditions, namely with and without electrostatic tactile feedback. This was followed by exploring the evolution of completion time (CT) with different indices of difficulties (ID). Experimental results with 12 participants indicated that the accuracy and completion time of pan gestures with added tactile feedback significantly exceeded those without tactile feedback. Furthermore, the relationship between CT and ID satisfied Fitts' Law with a correlation coefficient exceeding 0.9. Based on the findings, a "Tactile Fruit Sorting" game was designed, and subjective and objective evaluations were conducted. The results confirmed that the added tactile feedback enhanced both user performance and interest with respect to the game.

  6. Remotely deployable aerial inspection using tactile sensors

    Science.gov (United States)

    MacLeod, C. N.; Cao, J.; Pierce, S. G.; Sullivan, J. C.; Pipe, A. G.; Dobie, G.; Summan, R.

    2014-02-01

    For structural monitoring applications, the use of remotely deployable Non-Destructive Evaluation (NDE) inspection platforms offer many advantages, including improved accessibility, greater safety and reduced cost, when compared to traditional manual inspection techniques. The use of such platforms, previously reported by researchers at the University Strathclyde facilitates the potential for rapid scanning of large areas and volumes in hazardous locations. A common problem for both manual and remote deployment approaches lies in the intrinsic stand-off and surface coupling issues of typical NDE probes. The associated complications of these requirements are obviously significantly exacerbated when considering aerial based remote inspection and deployment, resulting in simple visual techniques being the preferred sensor payload. Researchers at Bristol Robotics Laboratory have developed biomimetic tactile sensors modelled on the facial whiskers (vibrissae) of animals such as rats and mice, with the latest sensors actively sweeping their tips across the surface in a back and forth motion. The current work reports on the design and performance of an aerial inspection platform and the suitability of tactile whisking sensors to aerial based surface monitoring applications.

  7. Tactile shoe inlays for high speed pressure monitoring

    DEFF Research Database (Denmark)

    Drimus, Alin; Mátéfi-Tempfli, Stefan

    2015-01-01

    This work describes the development of flexible tactile sensor shoe inlays for humanoid robots. Their design is based on a sandwich structure of flexible layers with a thin sheet of piezoresistive rubber as main transducer element. The layout and patterning of top and bottom electrodes give 1024...

  8. Force control in the absence of visual and tactile feedback

    NARCIS (Netherlands)

    Mugge, W.; Abbink, D.A.; Schouten, Alfred Christiaan; van der Helm, F.C.T.; Arendzen, J.H.; Meskers, C.G.M.

    2013-01-01

    Motor control tasks like stance or object handling require sensory feedback from proprioception, vision and touch. The distinction between tactile and proprioceptive sensors is not frequently made in dynamic motor control tasks, and if so, mostly based on signal latency. We previously found that

  9. Market study: Tactile paging system

    Science.gov (United States)

    1977-01-01

    A market survey was conducted regarding the commercialization potential and key market factors relevant to a tactile paging system for deaf-blind people. The purpose of the tactile paging system is to communicate to the deaf-blind people in an institutional environment. The system consists of a main console and individual satellite wrist units. The console emits three signals by telemetry to the wrist com (receiving unit) which will measure approximately 2 x 4 x 3/4 inches and will be fastened to the wrist by a strap. The three vibration signals are fire alarm, time period indication, and a third signal which will alert the wearer of the wrist com to the fact that the pin on the top of the wrist is emitting a morse coded message. The Morse code message can be felt and recognized with the finger.

  10. City Walks and Tactile Experience

    Directory of Open Access Journals (Sweden)

    Mădălina Diaconu

    2011-01-01

    Full Text Available This paper is an attempt to develop categories of the pedestrian’s tactile and kinaesthetic experience of the city. The beginning emphasizes the haptic qualities of surfaces and textures, which can be “palpated” visually or experienced by walking. Also the lived city is three-dimensional; its corporeal depth is discussed here in relation to the invisible sewers, protuberant profiles, and the formal diversity of roofscapes. A central role is ascribed in the present analysis to the formal similarities between the representation of the city by walking through it and the representation of the tactile form of objects. Additional aspects of the “tactile” experience of the city in a broad sense concern the feeling of their rhythms and the exposure to weather conditions. Finally, several aspects of contingency converge in the visible age of architectural works, which record traces of individual and collective histories.

  11. Can tactile sensory processing differentiate between children with autistic disorder and asperger's disorder?

    Science.gov (United States)

    Ghanizadeh, Ahmad

    2011-05-01

    There are debates whether autistic disorder (autism) and Asperger's disorder are two distinct disorders. Moreover, interventional sensory occupational therapy should consider the clinical characteristics of patients. Already, commonalities and differences between Asperger's disorder and autistic disorder are not well studied. The aim of this study is to compare tactile sensory function of children with autistic disorder and children with Asperger's disorder. Tactile sensory function was compared between 36 children with autism and 19 children with Asperger's disorder. The two disorders were diagnosed based on Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision. The parent-reported Tactile Dysfunction Checklist was used to assess the three aspects of hypersensitivity, hyposensitivity, and poor tactile perception and discrimination. Developmental coordination was also assessed. Developmental coordination problems total score was not associated with group. The mean (standard deviation) score of tactile hyper-responsivity was not different between the groups. Tactile hyporesponsivity and poor tactile perception and discrimination scores were statistically higher in autistic disorder than Asperger's disorder group. These results for the first time indicated that at least some aspects of tactile perception can differentiate these two disorders. Children with autistic disorder have more tactile sensory seeking behaviors than children with Asperger's disorder. Moreover, the ability of children with autistic disorder for tactile discrimination and sensory perception is less than those with Asperger's disorder. Interventional sensory therapy in children with autistic disorder should have some characteristics that can be different and specific for children with Asperger's disorder. Formal intelligence quotient testing was not performed on all of the children evaluated, which is a limitation to this study. In some cases, a clinical estimation of

  12. Can Tactile Sensory Processing Differentiate Between Children with Autistic Disorder and Asperger's Disorder?

    Science.gov (United States)

    2011-01-01

    Objective There are debates whether autistic disorder (autism) and Asperger's disorder are two distinct disorders. Moreover, interventional sensory occupational therapy should consider the clinical characteristics of patients. Already, commonalities and differences between Asperger's disorder and autistic disorder are not well studied. The aim of this study is to compare tactile sensory function of children with autistic disorder and children with Asperger's disorder. Methods Tactile sensory function was compared between 36 children with autism and 19 children with Asperger's disorder. The two disorders were diagnosed based on Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision. The parent-reported Tactile Dysfunction Checklist was used to assess the three aspects of hypersensitivity, hyposensitivity, and poor tactile perception and discrimination. Developmental coordination was also assessed. Results Developmental coordination problems total score was not associated with group. The mean (standard deviation) score of tactile hyper-responsivity was not different between the groups. Tactile hyporesponsivity and poor tactile perception and discrimination scores were statistically higher in autistic disorder than Asperger's disorder group. Conclusion These results for the first time indicated that at least some aspects of tactile perception can differentiate these two disorders. Children with autistic disorder have more tactile sensory seeking behaviors than children with Asperger's disorder. Moreover, the ability of children with autistic disorder for tactile discrimination and sensory perception is less than those with Asperger's disorder. Interventional sensory therapy in children with autistic disorder should have some characteristics that can be different and specific for children with Asperger's disorder. Formal intelligence quotient testing was not performed on all of the children evaluated, which is a limitation to this study. In

  13. Bilateral tactile agnosia: a case report.

    Science.gov (United States)

    Nakamura, J; Endo, K; Sumida, T; Hasegawa, T

    1998-06-01

    This study reports a 64-year-old right-handed male who manifested bilateral tactile recognition deficits. They were diagnosed as bilateral tactile agnosia, since the patient showed difficulty in semantic association of objects despite preserved hylognosis and morphognosis. The patient had a bilateral lesion in the subcortical region of the angular gyrus. The case reported by Endo et al. (1992) had a right hand tactile agnosia due to a subcortical lesion in the left angular gyrus. Our findings support Endo's hypothesis that tactile agnosia occurs when the somatosensory association cortex is disconnected from the semantic memory store located in the inferior temporal lobe by a subcortical lesion of the angular gyrus. We suggest that the extent of the lesion in the tactual-semantic pathway is related to the severity of tactile agnosia and the types of the tactile naming errors.

  14. The Perceived Urgency of Tactile Patterns

    Science.gov (United States)

    2011-06-01

    belt developed by Engineering Acoustics Inc. ( EAI ) was used to provide tactile stimuli. This adjustable belt, which consists of eight EAI C2 tactors...Acoustics Inc. ( EAI ) C2 tactile system was used, which consists of an adjustable tactile belt display (figure 1) worn around the waist and a receiver...unit. The adjustable belt display consists of eight EAI C2 tactors (acoustic transducers) that are approximately 1.2 inches in diameter. A belt

  15. Implicit body representations and tactile spatial remapping.

    Science.gov (United States)

    Longo, Matthew R; Mancini, Flavia; Haggard, Patrick

    2015-09-01

    To perceive the location of a tactile stimulus in external space (external tactile localisation), information about the location of the stimulus on the skin surface (tactile localisation on the skin) must be combined with proprioceptive information about the spatial location of body parts (position sense)--a process often referred to as 'tactile spatial remapping'. Recent research has revealed that both of these component processes rely on highly distorted implicit body representations. For example, on the dorsal hand surface position sense relies on a squat, wide hand representation. In contrast, tactile localisation on the same skin surface shows large biases towards the knuckles. These distortions can be seen as behavioural 'signatures' of these respective perceptual processes. Here, we investigated the role of implicit body representation in tactile spatial remapping by investigating whether the distortions of each of the two component processes (tactile localisation and position sense) also appear when participants localise the external spatial location of touch. Our study reveals strong distortions characteristic of position sense (i.e., overestimation of distances across vs along the hand) in tactile spatial remapping. In contrast, distortions characteristic of tactile localisation on the skin (i.e., biases towards the knuckles) were not apparent in tactile spatial remapping. These results demonstrate that a common implicit hand representation underlies position sense and external tactile localisation. Furthermore, the present findings imply that tactile spatial remapping does not require mapping the same signals in a frame of reference centred on a specific body part. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Design of a Large-scale Three-dimensional Flexible Arrayed Tactile Sensor

    Directory of Open Access Journals (Sweden)

    Junxiang Ding

    2011-01-01

    Full Text Available This paper proposes a new type of large-scale three-dimensional flexible arrayed tactile sensor based on conductive rubber. It can be used to detect three-dimensional force information on the continuous surface of the sensor, which realizes a true skin type tactile sensor. The widely used method of liquid rubber injection molding (LIMS method is used for "the overall injection molding" sample preparation. The structure details of staggered nodes and a new decoupling algorithm of force analysis are given. Simulation results show that the sensor based on this structure can achieve flexible measurement of large-scale 3-D tactile sensor arrays.

  17. Investigating Tactile Stimulation in Symbiotic Systems

    DEFF Research Database (Denmark)

    Orso, Valeria; Mazza, Renato; Gamberini, Luciano

    2017-01-01

    The core characteristics of tactile stimuli, i.e., recognition reliability and tolerance to ambient interference, make them an ideal candidate to be integrated into a symbiotic system. The selection of the appropriate stimulation is indeed important in order not to hinder the interaction from...... the user’s perspective. Here we present the process of selecting the most adequate tactile stimulation delivered by a tactile vest while users were engaged in an absorbing activity, namely playing a video-game. A total of 20 participants (mean age 24.78; SD= 1.57) were involved. Among the eight tactile...

  18. Flexible PZT Thin Film Tactile Sensor for Biomedical Monitoring

    Directory of Open Access Journals (Sweden)

    Wen-Jong Wu

    2013-04-01

    Full Text Available This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 μm on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g.

  19. The Perceived Urgency of Tactile Patterns During Dismounted Soldier Movements

    Science.gov (United States)

    2012-05-01

    tactile system including an adjustable belt developed by Engineering Acoustics, Inc. ( EAI ), provided the tactile stimuli. This adjustable belt...which consists of eight EAI C2 tactors positioned at 45° intervals, was worn around each participant’s waist. Participants received tactile patterns...Tactile System An Engineering Acoustics, Inc. ( EAI ) C2 tactile system was used, which consisted of an adjustable tactile belt display (figure 1) worn

  20. Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults

    OpenAIRE

    Heed, Tobias; Roeder, Brigitte; Badde, Stephanie; Schubert, Jonathan

    2017-01-01

    Task demands modulate tactile localization in sighted humans, presumably through weight adjustments in the spatial integration of anatomical, skin-based, and external, posture-based information. In contrast, previous studies have suggested that congenitally blind humans, by default, refrain from automatic spatial integration and localize touch using only skin-based information. Here, sighted and congenitally blind participants localized tactile targets on the palm or back of one hand, while i...

  1. Tactile roughness discrimination threshold is unrelated to tactile spatial acuity.

    Science.gov (United States)

    Libouton, Xavier; Barbier, Olivier; Plaghki, Leon; Thonnard, Jean-Louis

    2010-04-02

    The present study examined the relationship between the tactile roughness discrimination threshold (TRDT) and the tactile spatial resolution threshold (TSRT) at the index fingertip in humans. A new device was built for measuring TRDT, allowing pair-wise presentations of two sets of six different sandpaper grits. The smoothest grits ranged from 18 to 40 microm and the roughest grits ranged from 50 to 195 microm particle size. The reference sandpaper had a 46 microm particle size. A two-alternative forced choice paradigm and a double interlaced adaptive staircase procedure yielding a 75% just noticeable difference (75%jnd) was used according to Zwislocki and Relkin. Contact force and scanning velocity were measured at the fingertip with a built-in sensor. The TSRT was assessed with an extended set of grating domes. Fifty-three male and female subjects, spanning a wide age range participated in this study. The JND75% or TRDT was lower for the smoothest sandpapers (15+/-8.5 microm) compared to the roughest sandpapers (44+/-32.5 microm). TRDT performance was unrelated to age or gender. Additionally, grit size had no effect on the mean forces (normal and tangential) exerted at the fingertip or the mean scan velocities. In contrast, there was a significant degradation of TSRT performance with age. Lastly, there was no significant correlation between TRDT and TRST performance. Results of this study support the theory that the neural mechanisms underlying the perception of tactile roughness discrimination for fine textures differ from those involved in spatial resolution acuity often associated with the SA1 afferents. Copyright 2009 Elsevier B.V. All rights reserved.

  2. A flexible tactile sensitive sheet using a hetero-core fiber optic sensor

    Science.gov (United States)

    Fujino, S.; Yamazaki, H.; Hosoki, A.; Watanabe, K.

    2014-05-01

    In this report, we have designed a tactile sensitive sheet based on a hetero-core fiber-optic sensor, which realize an areal sensing by using single sensor potion in one optical fiber line. Recently, flexible and wide-area tactile sensing technology is expected to applied to acquired biological information in living space and robot achieve long-term care services such as welfare and nursing-care and humanoid technology. A hetero-core fiber-optic sensor has several advantages such as thin and flexible transmission line, immunity to EMI. Additionally this sensor is sensitive to moderate bending actions with optical loss changes and is independent of temperature fluctuation. Thus, the hetero-core fiber-optic sensor can be suitable for areal tactile sensing. We measure pressure characteristic of the proposed sensitive sheet by changing the pressure position and pinching characteristic on the surface. The proposed tactile sensitive sheet shows monotonic responses on the whole sensitive sheet surface although different sensitivity by the position is observed at the sensitive sheet surface. Moreover, the tactile sensitive sheet could sufficiently detect the pinching motion. In addition, in order to realize the discrimination between pressure and pinch, we fabricated a doubled-over sensor using a set of tactile sensitive sheets, which has different kinds of silicon robbers as a sensitive sheet surface. In conclusion, the flexible material could be given to the tactile sensation which is attached under proposed sensitive sheet.

  3. Movement Induces the Use of External Spatial Coordinates for Tactile Localization in Congenitally Blind Humans.

    Science.gov (United States)

    Heed, Tobias; Möller, Johanna; Röder, Brigitte

    2015-01-01

    To localize touch, the brain integrates spatial information coded in anatomically based and external spatial reference frames. Sighted humans, by default, use both reference frames in tactile localization. In contrast, congenitally blind individuals have been reported to rely exclusively on anatomical coordinates, suggesting a crucial role of the visual system for tactile spatial processing. We tested whether the use of external spatial information in touch can, alternatively, be induced by a movement context. Sighted and congenitally blind humans performed a tactile temporal order judgment task that indexes the use of external coordinates for tactile localization, while they executed bimanual arm movements with uncrossed and crossed start and end postures. In the sighted, start posture and planned end posture of the arm movement modulated tactile localization for stimuli presented before and during movement, indicating automatic, external recoding of touch. Contrary to previous findings, tactile localization of congenitally blind participants, too, was affected by external coordinates, though only for stimuli presented before movement start. Furthermore, only the movement's start posture, but not the planned end posture affected blind individuals' tactile performance. Thus, integration of external coordinates in touch is established without vision, though more selectively than when vision has developed normally, and possibly restricted to movement contexts. The lack of modulation by the planned posture in congenitally blind participants suggests that external coordinates in this group are not mediated by motor efference copy. Instead the task-related frequent posture changes, that is, movement consequences rather than planning, appear to have induced their use of external coordinates.

  4. Tactile sensibility on the fingernail.

    Science.gov (United States)

    Seah, Benjamin Zhi Qiang; Wu, Clement Chun Ho; Sebastin, Sandeep Jacob; Lahiri, Amitabha

    2013-11-01

    To measure tactile discrimination (static and moving 2-point discrimination) and threshold levels (Weinstein enhanced sensory test) over the nail plate in normal subjects and compare these values with those at the corresponding finger pulps. Tactile discrimination and threshold values over the nail plates and finger pulps were measured on 300 digits in 30 healthy subjects with a mean age of 23 years. Subjects with cosmetic nail modifications, injuries, neurological deficits, dermatological conditions, or history of upper limb surgery were excluded. Equivalence testing was conducted to look for clinical equivalence between values obtained at both sites. The mean static 2-point discrimination, moving 2-point discrimination, and threshold value over the human nail were 6.7 mm, 2.4 mm, and 0.06 g, respectively. The corresponding values for the finger pulp were 2.4 mm, 2.2 mm, and 0.01 g, respectively. The static 2-point discrimination and threshold values were superior for the finger pulp, whereas moving 2-point discrimination values at both sites were clinically equivalent. Our study suggests that tactile discrimination and threshold levels can be measured over the nail plate and that moving 2-point discrimination values are clinically equivalent to those obtained on the corresponding pulp. This highlights the importance of the nail plate in the sensory function of the fingertip. The normative data from this study may be useful in establishing the impact of nail injury and the contribution of the nail to the overall function of the hand. Diagnostic II. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  5. The Design of Tactile Thematic Symbols

    Science.gov (United States)

    Lawrence, Megan M.; Lobben, Amy K.

    2011-01-01

    The study reported here investigated the design and legibility of tactile thematic maps, focusing on symbolization and the comprehension of spatial patterns on the maps. The results indicate that discriminable and effective tactile thematic maps can be produced using classed data with a microcapsule paper production method. The participants…

  6. Automatic Transcription of Tactile Maps. Practice Report

    Science.gov (United States)

    Papadopoulos, Konstantinos

    2005-01-01

    Tactile maps are an important means for the education and mobility of people who are visually impaired (that is, are blind or have low vision). Because of the importance of tactile maps, it is essential that they are accessible to people who are visually impaired and correctly interpreted. There has been considerable research on the design of…

  7. Vibrobelt: Tactile Navigation Support for Cyclists

    NARCIS (Netherlands)

    Steltenpohl, H.; Bouwer, A.

    2013-01-01

    Tactile displays can be used without demanding the attention from the human visual system, which makes them attractive for use in wayfinding contexts, where visual attention should be directed at traffic and other information in the environment. To investigate the potential of tactile navigation for

  8. Autism: tactile perception and emotion.

    Science.gov (United States)

    Pernon, E; Pry, R; Baghdadli, A

    2007-08-01

    For many years, and especially since Waynbaum and Wallon, psychology and psychopathology have dealt with cognitive perception, but have had little to do with the affective qualities of perception. Our aim was to study the influence of the sensory environment on people with autism. Several experiments were carried out using different forms of tactile stimulation (passive and active subjects). Our data showed specific responses in children with autism and intellectual disability. These children displayed a strong (positive) valence to the stimulation provided. They were very attracted to the stimulation and were excited by it.

  9. Concurrent emotional pictures modulate temporal order judgments of spatially separated audio-tactile stimuli.

    Science.gov (United States)

    Jia, Lina; Shi, Zhuanghua; Zang, Xuelian; Müller, Hermann J

    2013-11-06

    Although attention can be captured toward high-arousal stimuli, little is known about how perceiving emotion in one modality influences the temporal processing of non-emotional stimuli in other modalities. We addressed this issue by presenting observers spatially uninformative emotional pictures while they performed an audio-tactile temporal-order judgment (TOJ) task. In Experiment 1, audio-tactile stimuli were presented at the same location straight ahead of the participants, who had to judge "which modality came first?". In Experiments 2 and 3, the audio-tactile stimuli were delivered one to the left and the other to the right side, and participants had to judge "which side came first?". We found both negative and positive high-arousal pictures to significantly bias TOJs towards the tactile and away from the auditory event when the audio-tactile stimuli were spatially separated; by contrast, there was no such bias when the audio-tactile stimuli originated from the same location. To further examine whether this bias is attributable to the emotional meanings conveyed by the pictures or to their high arousal effect, we compared and contrasted the influences of near-body threat vs. remote threat (emotional) pictures on audio-tactile TOJs in Experiment 3. The bias manifested only in the near-body threat condition. Taken together, the findings indicate that visual stimuli conveying meanings of near-body interaction activate a sensorimotor functional link prioritizing the processing of tactile over auditory signals when these signals are spatially separated. In contrast, audio-tactile signals from the same location engender strong crossmodal integration, thus counteracting modality-based attentional shifts induced by the emotional pictures. © 2013 Published by Elsevier B.V.

  10. The role of the sliding direction against a grooved channel texture on tool steel: An experimental study on tactile friction

    NARCIS (Netherlands)

    Zhang, S.; Rodriguez Urribarri, A.; Morales Hurtado, M.; Zeng, X.; Heide, E. van der

    2015-01-01

    To control tactile friction, that is the friction between fingertip and counter-body, the role of surface texture is required to be unveiled and defined. In this research, an experimental approach is used based on measuring tactile friction for directional texture (grooved channel) with varying

  11. The Development of Tactile Perception.

    Science.gov (United States)

    Bremner, A J; Spence, C

    2017-01-01

    Touch is the first of our senses to develop, providing us with the sensory scaffold on which we come to perceive our own bodies and our sense of self. Touch also provides us with direct access to the external world of physical objects, via haptic exploration. Furthermore, a recent area of interest in tactile research across studies of developing children and adults is its social function, mediating interpersonal bonding. Although there are a range of demonstrations of early competence with touch, particularly in the domain of haptics, the review presented here indicates that many of the tactile perceptual skills that we take for granted as adults (e.g., perceiving touches in the external world as well as on the body) take some time to develop in the first months of postnatal life, likely as a result of an extended process of connection with other sense modalities which provide new kinds of information from birth (e.g., vision and audition). Here, we argue that because touch is of such fundamental importance across a wide range of social and cognitive domains, it should be placed much more centrally in the study of early perceptual development than it currently is. © 2017 Elsevier Inc. All rights reserved.

  12. Design of a flexible tactile sensor for classification of rigid and deformable objects

    DEFF Research Database (Denmark)

    Drimus, Alin; Kootstra, Gert; Bilberg, Arne

    2014-01-01

    For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a novel tactile-array sensor based on flexible piezoresistive rubber.We describe the design of the sensor...... of the sensor in an active object-classification system. A robotic gripper with two sensors mounted on its fingers performs a palpation procedure on a set of objects. By squeezing an object, the robot actively explores the material properties, and the system acquires tactile information corresponding...... to the resulting pressure. Based on a k-nearest neighbor classifier and using dynamic time warping to calculate the distance between different time series, the system is able to successfully classify objects. Our sensor demonstrates similar classification performance to the Weiss Robotics tactile sensor, while...

  13. Effects of fusion between tactile and proprioceptive inputs on tactile perception.

    Directory of Open Access Journals (Sweden)

    Jay P Warren

    2011-03-01

    Full Text Available Tactile perception is typically considered the result of cortical interpretation of afferent signals from a network of mechanical sensors underneath the skin. Yet, tactile illusion studies suggest that tactile perception can be elicited without afferent signals from mechanoceptors. Therefore, the extent that tactile perception arises from isomorphic mapping of tactile afferents onto the somatosensory cortex remains controversial. We tested whether isomorphic mapping of tactile afferent fibers onto the cortex leads directly to tactile perception by examining whether it is independent from proprioceptive input by evaluating the impact of different hand postures on the perception of a tactile illusion across fingertips. Using the Cutaneous Rabbit Effect, a well studied illusion evoking the perception that a stimulus occurs at a location where none has been delivered, we found that hand posture has a significant effect on the perception of the illusion across the fingertips. This finding emphasizes that tactile perception arises from integration of perceived mechanical and proprioceptive input and not purely from tactile interaction with the external environment.

  14. Micro-needle electro-tactile display.

    Science.gov (United States)

    Tezuka, Mayuko; Kitamura, Norihide; Miki, Norihisa

    2015-08-01

    Haptic feedback is strongly demanded for high-precision robot-assisted surgery and teleoperation. The haptic feedback consists of force and tactile feedback, however tactile feedback has been little studied and the size and weight of the system poses challenges for practical applications. In this paper we propose a sheet-type wearable electro-tactile display which provides tactile sensations to the user as the feedback at a low voltage and power consumption. The display possesses needle-shaped electrodes, which can penetrate through the high-impedance stratum corneum. We developed the fabrication process and, as the first step, we investigated the tactile sensation that can be created to the fingertip by the display. Rough and smooth surfaces were successfully presented to the user. Then, we characterized the tactile display when used on the forearm, in particular, with respect to the spatial resolution. These tactile displays can be used to inform the user of the surface property of the parts of interest, such as tumor tissues, and to guide him in the manipulation of surgery robots.

  15. A Light Harvesting, Self-Powered Monolith Tactile Sensor Based on Electric Field Induced Effects in MAPbI3 Perovskite.

    Science.gov (United States)

    Saraf, Rohit; Pu, Long; Maheshwari, Vivek

    2018-03-01

    Organolead trihalide perovskite MAPbI 3 shows a distinctive combination of properties such as being ferroelectric and semiconducting, with ion migration effects under poling by electric fields. The combination of its ferroelectric and semiconducting nature is used to make a light harvesting, self-powered tactile sensor. This sensor interfaces ZnO nanosheets as a pressure-sensitive drain on the MAPbI 3 film and once poled is operational for at least 72 h with just light illumination. The sensor is monolithic in structure, has linear response till 76 kPa, and is able to operate continuously as the energy harvesting mechanism is decoupled from its pressure sensing mechanism. It has a sensitivity of 0.57 kPa -1 , which can be modulated by the strength of the poling field. The understanding of these effects in perovskite materials and their application in power source free devices are of significance to a wide array of fields where these materials are being researched and applied. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Tactile feedback improves auditory spatial localization.

    Science.gov (United States)

    Gori, Monica; Vercillo, Tiziana; Sandini, Giulio; Burr, David

    2014-01-01

    Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

  17. Tactile feedback improves auditory spatial localization

    Directory of Open Access Journals (Sweden)

    Monica eGori

    2014-10-01

    Full Text Available Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial-bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014. To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile-feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject’s forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal-feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no-feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially coherent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

  18. Classification of rigid and deformable objects using a novel tactile sensor

    DEFF Research Database (Denmark)

    Drimus, Alin; Kootstra, Gert; Bilberg, Arne

    2011-01-01

    In this paper, we present a novel array tactile sensor for use in robotic grippers based on a flexible piezoresistive rubber. We start by describing the physical principles of piezoresistive materials and continue by outlining how to build a flexible array tactile sensor using stitch electrodes...... various rigid and deformable objects. We represent the array of tactile images for each grasped object to a time series of features and use this as the input for a KNN classifier. Dynamic time warping is used for calculating distances between different time series of features. In the end, we compare...... the results with the ones obtained from an experimental setup that uses a Weiss Robotics tactile sensor with similar characteristics and we conclude by exemplifying how the results of the classification can be used in different industrial applications....

  19. Making sense. What can we learn from experts of tactile knowledge?

    Directory of Open Access Journals (Sweden)

    Camilla Groth

    2013-09-01

    Full Text Available This article describes an embodied way of making sense through making with the hands. We examine the potential o ftactile experience in the making process and analyse what tactile experiences mean. The study takes place in the context of an era marked by audio-visual dominance.The article presents a case study that observed and interviewed deafblind makers while they worked with clay. The findings reveal that modelling in clay resembles the visualisation process of sketching. As such, it may contribute to thinking through the hands. Language is not a self-evident communication tool for transferring tactile skills. Based on our case study, we propose the use of tactile communication in the process of transferring tactile knowledge through making with another person’s hands.

  20. Tactile object exploration using cursor navigation sensors

    DEFF Research Database (Denmark)

    Kraft, Dirk; Bierbaum, Alexander; Kjaergaard, Morten

    2009-01-01

    In robotic applications tactile sensor systems serve the purpose of localizing a contact point and measuring contact forces. We have investigated the applicability of a sensorial device commonly used in cursor navigation technology for tactile sensing in robotics. We show the potential...... aspect of this sensor is that beside a localization of contact points and measurement of the contact normal force also shear forces can be measured. This is relevant for many applications such as surface normal estimation and weight measurements. Scalable tactile sensor arrays have been developed...

  1. Development of a Tactile Sensor Array

    DEFF Research Database (Denmark)

    Marian, Nicolae; Drimus, Alin; Bilberg, Arne

    2010-01-01

    . The paper describes the related research work we have developed for sensor design, exploration and control for a robot gripping system, in order to analyze normal forces applied on the tactile pixels for gripping force control and generate tactile images for gripping positioning and object recognition....... Section 1 gives an introduction of principles and technologies in tactile sensing for robot grippers. Section 2 presents the sensor cell (taxel) and array design and characterization. Section 3 introduces object recognition and shape analysis ideas showing a few preliminary examples, where geometrical...

  2. TACTILE SENSING FOR OBJECT IDENTIFICATION

    DEFF Research Database (Denmark)

    Drimus, Alin; Marian, Nicolae; Bilberg, Arne

    2009-01-01

    The artificial sense of touch is a research area that can be considered still in demand, compared with the human dexterity of grasping a wide variety of shapes and sizes, perform complex tasks, and switch between grasps in response to changing task requirements. For handling unknown objects...... described the working principles of a few types of tactile sensing cells, focusing on the piezoresistive materials. Starting from a set of requirements for developing a high resolution flexible array sensor we have investigated if CSA pressure sensitive conductive rubber could be a proper candidate and can...... be used for building an array sensor prototype. Comparing different sensing cell structures in terms of output characteristics, we propose a simple, cheap, yet robust prototype, and we validate that it can be used for object recognition and shape analysis showing a few preliminary examples, where...

  3. Design and experimental evaluation of a tactile display featuring magnetorheological fluids

    Science.gov (United States)

    Han, Young-Min; Oh, Jong-Seok; Kim, Jin-Kuy; Choi, Seung-Bok

    2014-07-01

    This paper proposes a novel type of tactile display utilizing magnetorheological (Mr) fluid which can be applied to a robotic system in minimally invasive surgery to provide a surgeon with tactile information on remote biological tissues or organs. As a first step, an actuation mechanism for tactile function is devised utilizing the Mr fluid with a pin array mechanism. Based on the force responses of a human body, the tactile display is appropriately designed and a magnetic analysis is carried out to determine the design parameters using the finite element method. After evaluating the field-dependent force characteristics of the manufactured tactile display, a feed-forward control algorithm based on fuzzy logic is formulated to obtain the desired palpation force. Control performance is demonstrated via palpation force evaluation and psychophysical evaluation. In the results, the actual repulsive forces agreed well with the desired forces and the averaged relative error was less than 1.3%. In addition, the volunteers successfully recognized tactility with a favorable rating value of 3.36 on a five-point scale.

  4. Flow of cortical activity underlying a tactile decision in mice

    OpenAIRE

    Guo, Zengcai V.; Li, Nuo; Huber, Daniel; Ophir, Eran; Gutnisky, Diego; Ting, Jonathan T.; Feng, Guoping; Svoboda, Karel

    2013-01-01

    Perceptual decisions involve distributed cortical activity. Does information flow sequentially from one cortical area to another, or do networks of interconnected areas contribute at the same time? Here we delineate when and how activity in specific areas drives a whisker-based decision in mice. A short-term memory component temporally separated tactile “sensation” and “action” (licking). Using optogenetic inhibition (spatial resolution, 2 mm; temporal resolution, 100 ms), we surveyed the neo...

  5. Tactile Data Entry System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Building on our successful Phase I Tactile Data Entry program, Barron Associates proposes development of a Glove-Enabled Computer Operations (GECO) system to permit...

  6. Object texture recognition by dynamic tactile sensing using active exploration

    DEFF Research Database (Denmark)

    Drimus, Alin; Børlum Petersen, Mikkel; Bilberg, Arne

    For both humans and robots, tactile sensing is important for interaction with the environment: it is the core sensing used for exploration and manipulation of objects. In this paper, we present a method for determining object texture by active exploration with a robotic fingertip equipped...... with a dynamic tactile transducer based on polyvinylidene fluoride (PVDF) piezoelectric film. Different test surfaces are actively explored and the signal from the sensor is used for feature extraction, which is subsequently used for classification. A comparison between the significance of different extracted...... features and performance of learning algorithms is done and the best method is further used to classify objects by their surface textures with recognition results higher than 90 percent....

  7. Tactile-Foot Stimulation Can Assist the Navigation of People with Visual Impairment

    Directory of Open Access Journals (Sweden)

    Ramiro Velázquez

    2015-01-01

    Full Text Available Background. Tactile interfaces that stimulate the plantar surface with vibrations could represent a step forward toward the development of wearable, inconspicuous, unobtrusive, and inexpensive assistive devices for people with visual impairments. Objective. To study how people understand information through their feet and to maximize the capabilities of tactile-foot perception for assisting human navigation. Methods. Based on the physiology of the plantar surface, three prototypes of electronic tactile interfaces for the foot have been developed. With important technological improvements between them, all three prototypes essentially consist of a set of vibrating actuators embedded in a foam shoe-insole. Perceptual experiments involving direction recognition and real-time navigation in space were conducted with a total of 60 voluntary subjects. Results. The developed prototypes demonstrated that they are capable of transmitting tactile information that is easy and fast to understand. Average direction recognition rates were 76%, 88.3%, and 94.2% for subjects wearing the first, second, and third prototype, respectively. Exhibiting significant advances in tactile-foot stimulation, the third prototype was evaluated in navigation tasks. Results show that subjects were capable of following directional instructions useful for navigating spaces. Conclusion. Footwear providing tactile stimulation can be considered for assisting the navigation of people with visual impairments.

  8. Endoscopic vs. tactile evaluation of subgingival calculus.

    Science.gov (United States)

    Osborn, Joy B; Lenton, Patricia A; Lunos, Scott A; Blue, Christine M

    2014-08-01

    Endoscopic technology has been developed to facilitate imagery for use during diagnostic and therapeutic phases of periodontal care. The purpose of this study was to compare the level of subgingival calculus detection using a periodontal endoscope with that of conventional tactile explorer in periodontitis subjects. A convenience sample of 26 subjects with moderate periodontitis in at least 2 quadrants was recruited from the University of Minnesota School of Dentistry to undergo quadrant scaling and root planing. One quadrant from each subject was randomized for tactile calculus detection alone and the other quadrant for tactile detection plus the Perioscope ™ (Perioscopy Inc., Oakland, Cali). A calculus index on a 0 to 3 score was performed at baseline and at 2 post-scaling and root planing visits. Sites where calculus was detected at visit 1 were retreated. T-tests were used to determine within-subject differences between Perioscope™ and tactile measures, and changes in measures between visits. Significantly more calculus was detected using the Perioscope™ vs. tactile explorer for all 3 subject visits (pcalculus detection from baseline to visit 1 were statistically significant for both the Perioscope™ and tactile quadrants (pcalculus detection from visit 1 to visit 2 was only significant for the Perioscope™ quadrant (pcalculus at this visit. It was concluded that the addition of a visual component to calculus detection via the Perioscope™ was most helpful in the re-evaluation phase of periodontal therapy. Copyright © 2014 The American Dental Hygienists’ Association.

  9. Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

    Directory of Open Access Journals (Sweden)

    Shuzhi Sam Ge

    2011-09-01

    Full Text Available One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects’ shapes and, more specifically, the objects’ surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB, Artificial Neural Networks (ANN, and Support Vector Machines (SVM were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination.

  10. Ambiguity in Tactile Apparent Motion Perception.

    Directory of Open Access Journals (Sweden)

    Emanuela Liaci

    Full Text Available In von Schiller's Stroboscopic Alternative Motion (SAM stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio ("AR", i.e. the relation between vertical and horizontal dot distances. Further, with equal horizontal and vertical dot distances (AR = 1 perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion.We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants' forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames.Increasing the tactile SAM's AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias.Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual strategy of the individual

  11. Freezing in Touch: Sound Enhances Tactile Perception

    Directory of Open Access Journals (Sweden)

    Ya-Yeh Tsai

    2011-10-01

    Full Text Available Perceptual segregation in rapidly changing visual displays can be facilitated by a synchronized salient sound that segregates itself from other sounds in the sequence (Vroomen & de Gelder, 2000. We examined whether this “freezing” phenomenon can also be found in tactile perception. Three vibrators were placed on the participant's palm to produce four different tactile patterns. Four sounds were presented separately and simultaneously with each of the four tactile patterns. Among the three same-pitch tones, an abrupt high-pitch tone was presented simultaneously with the designated temporal position of the target pattern in the sequence of tactual stimuli that was presented rapidly and repeatedly. The task was to identify the tactile pattern of the target. Results showed that participants responded faster and more accurately with the high-pitch tone, compared to the condition when all the tones were of the same pitch. However, the result reversed when an extra tactile cue was presented on the wrist. This suggests that a salient auditory signal can improve perceptual segregation not only in vision but also in touch. That is, it is a cross-modal facilitation, not an alerting or attentional cueing effect.

  12. Generation of tactile maps for artificial skin.

    Directory of Open Access Journals (Sweden)

    Simon McGregor

    Full Text Available Prior research has shown that representations of retinal surfaces can be learned from the intrinsic structure of visual sensory data in neural simulations, in robots, as well as by animals. Furthermore, representations of cochlear (frequency surfaces can be learned from auditory data in neural simulations. Advances in hardware technology have allowed the development of artificial skin for robots, realising a new sensory modality which differs in important respects from vision and audition in its sensorimotor characteristics. This provides an opportunity to further investigate ordered sensory map formation using computational tools. We show that it is possible to learn representations of non-trivial tactile surfaces, which require topologically and geometrically involved three-dimensional embeddings. Our method automatically constructs a somatotopic map corresponding to the configuration of tactile sensors on a rigid body, using only intrinsic properties of the tactile data. The additional complexities involved in processing the tactile modality require the development of a novel multi-dimensional scaling algorithm. This algorithm, ANISOMAP, extends previous methods and outperforms them, producing high-quality reconstructions of tactile surfaces in both simulation and hardware tests. In addition, the reconstruction turns out to be robust to unanticipated hardware failure.

  13. Tactile Stimulation Reduces Fear in Fish

    Directory of Open Access Journals (Sweden)

    Annett eSchirmer

    2013-11-01

    Full Text Available Being groomed or touched can counter stress and negative affect in mammals. In two experiments we explored whether a similar phenomenon exists in non-mammals like zebrafish. In Experiment 1, we exposed zebrafish to a natural stressor, a chemical alarm signal released by injured conspecifics. Before moving them into an observation tank, one group of fish was washed and then subjected to a water current that served as the tactile stimulus. The other group was simply washed. Fish with tactile treatment demonstrated fewer fear behaviors (e.g., bottom dwelling and lower cortisol levels than fish without. In Experiment 2, we ascertained a role of somatosensation in these effects. Using a similar paradigm as in Experiment 1, we recorded fear behaviors of intact fish and fish with damaged lateral line hair cells. Relative to the former, the latter benefited less from the tactile stimulus during fear recovery. Together these findings show that tactile stimulation can calm fish and that tactile receptors, evolutionarily older than those present in mammals, contribute to this phenomenon.

  14. Robotic Tactile Sensing Technologies and System

    CERN Document Server

    Dahiya, Ravinder S

    2013-01-01

    Future robots are expected to work closely and interact safely with real-world objects and humans alike. Sense of touch is important in this context, as it helps estimate properties such as shape, texture, hardness, material type and many more; provides action related information, such as slip detection; and helps carrying out actions such as rolling an object between fingers without dropping it. This book presents an in-depth description of the solutions available for gathering tactile data, obtaining aforementioned tactile information from the data and effectively using the same in various robotic tasks. Better integration of tactile sensors on a robot’s body is prerequisite for the effective utilization of tactile data. For this reason, the hardware, software and application related issues (and resulting trade-offs) that must be considered to make tactile sensing an effective component of robotic platforms are discussed in-depth.To this end, human touch sensing has also been explored. The design hints co...

  15. Tactile Perception for Stroke Induce Changes in Electroencephalography

    Directory of Open Access Journals (Sweden)

    Si-Nae Ahn

    2016-12-01

    Conclusion: The results of this study provided a neurophysiological evidence on tactile perception in individuals with chronic stroke. Occupational therapists should consider an active tactile exploration as a useful modality on occupational performance in rehabilitation training.

  16. A critical experimental study of the classical tactile threshold theory

    Directory of Open Access Journals (Sweden)

    Medina Leonel E

    2010-06-01

    level. Nevertheless, our experimental results are above that chance level. Therefore, if detection exists below the classical threshold level, then the model to explain the SR phenomenon or any other tactile perception phenomena based on the psychophysical classical threshold is not valid. We conclude that a more suitable model of the tactile sensory system is needed.

  17. Bouba/Kiki in Touch: Associations Between Tactile Perceptual Qualities and Japanese Phonemes

    Directory of Open Access Journals (Sweden)

    Maki Sakamoto

    2018-03-01

    Full Text Available Several studies have shown cross-modal associations between sounds and vision or gustation by asking participants to match pre-defined sound-symbolic words (SSWs, such as “bouba” or “kiki,” with visual or gustatory materials. Here, we conducted an explorative study on cross-modal associations of tactile sensations using spontaneous production of Japanese SSWs and semantic ratings. The Japanese language was selected, because it has a large number of SSWs that can represent a wide range of tactile perceptual spaces with fine resolution, and it shows strong associations between sound and touch. In the experiment, we used 120 everyday materials to cover basic material categories that could be associated with fundamental dimensions of tactile perception. Upon contact with these materials, participants expressed their tactile sensations by using Japanese SSWs, and at the same time, evaluated the tactile sensations by semantic differential scales using adjective pairs. Thanks to the variety of testing materials, we were able to demonstrate the existence of systematic associations between sounds and tactile fundamental perceptual dimensions in a more detailed and comprehensive way than ever done so before. In particular, we found that for vowels, positive tactile ratings were associated with the back vowel (/u/, while negative ratings were associated with the front vowels (/i/ and /e/. The central vowels (/o/ and /a/ were mainly associated with rough, hard, and dry feelings. Consonants were categorized based on vocal features and articulation. The category of the voiced consonants (e.g., /dz/ and /g/ corresponded to feelings of roughness, while that of voiceless consonants (e.g., /ʦ/, and /s/ corresponded to feelings of smoothness. The categories of the bilabial plosive (/p/ and /b/ and voiced alveolar nasal (/n/ consonants were mainly related to soft, sticky and wet feelings, while that of voiceless alveolar affricate (/ʦ/ and voiceless velar

  18. Magnetic Tactile Sensor for Braille Reading

    KAUST Repository

    Alfadhel, Ahmed

    2016-04-27

    We report a biomimetic magnetic tactile sensor for Braille characters reading. The sensor consists of magnetic nanocomposite artificial cilia implemented on magnetic micro sensors. The nanocomposite is produced from the highly elastic polydimethylsiloxane and iron nanowires that exhibit a permanent magnetic behavior. This design enables remote operation and does not require an additional magnetic field to magnetize the nanowires. The highly elastic nanocomposite is easy to pattern, corrosion resistant and thermally stable. The tactile sensors can detect vertical and shear forces, which allows recognizing small changes in surface texture, as in the case of Braille dots. The 6 dots of a braille cell are read from top to bottom with a tactile sensor array consisting of 4 elements and 1 mm long nanocomposite cilia.

  19. Representation of Simple Graphs in Virtual Tactile Space.

    Science.gov (United States)

    Wyatt, Harry J.; Hall, Elaine C.; Engber, Kimberly

    2000-01-01

    A project developed and evaluated an intermediate form of presentation that provides a virtual dynamic tactile display for use with computers that could complement static tactile displays of graphical material. The device is a two-dimensional extension of the tactile mouse and provides contour and slope information to the user. (Contains nine…

  20. Tactile sensing means for prosthetic limbs

    Science.gov (United States)

    Scott, W. L. (Inventor)

    1973-01-01

    An improved prosthetic device characterized by a frame and a socket for mounting on the stump of a truncated human appendage is described. Flexible digits extend from the distal end and transducers located within the digits act as sensing devices for detecting tactile stimuli. The transducers are connected through a power circuit with a slave unit supported by a strap and fixed to the stump. The tactile stimuli detected at the sensing devices are reproduced and applied to the skin of the appendage in order to stimulate the sensory organs located therein.

  1. Vibration-enhanced posture stabilization achieved by tactile supplementation: may blind individuals get extra benefits?

    Science.gov (United States)

    Magalhães, Fernando Henrique; Kohn, André Fabio

    2011-08-01

    Diminished balance ability poses a serious health risk due to the increased likelihood of falling, and impaired postural stability is significantly associated with blindness and poor vision. Noise stimulation (by improving the detection of sub-threshold somatosensory information) and tactile supplementation (i.e., additional haptic information provided by an external contact surface) have been shown to improve the performance of the postural control system. Moreover, vibratory noise added to the source of tactile supplementation (e.g., applied to a surface that the fingertip touches) has been shown to enhance balance stability more effectively than tactile supplementation alone. In view of the above findings, in addition to the well established consensus that blind subjects show superior abilities in the use of tactile information, we hypothesized that blind subjects may take extra benefits from the vibratory noise added to the tactile supplementation and hence show greater improvements in postural stability than those observed for sighted subjects. If confirmed, this hypothesis may lay the foundation for the development of noise-based assistive devices (e.g., canes, walking sticks) for improving somatosensation and hence prevent falls in blind individuals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Biologically inspired multi-layered synthetic skin for tactile feedback in prosthetic limbs.

    Science.gov (United States)

    Osborn, Luke; Nguyen, Harrison; Betthauser, Joseph; Kaliki, Rahul; Thakor, Nitish

    2016-08-01

    The human body offers a template for many state-of-the-art prosthetic devices and sensors. In this work, we present a novel, sensorized synthetic skin that mimics the natural multi-layered nature of mechanoreceptors found in healthy glabrous skin to provide tactile information. The multi-layered sensor is made up of flexible piezoresistive textiles that act as force sensitive resistors (FSRs) to convey tactile information, which are embedded within a silicone rubber to resemble the compliant nature of human skin. The top layer of the synthetic skin is capable of detecting small loads less than 5 N whereas the bottom sensing layer responds reliably to loads over 7 N. Finite element analysis (FEA) of a simplified human fingertip and the synthetic skin was performed. Results suggest similarities in behavior during loading. A natural tactile event is simulated by loading the synthetic skin on a prosthetic limb. Results show the sensors' ability to detect applied loads as well as the ability to simulate neural spiking activity based on the derivative and temporal differences of the sensor response. During the tactile loading, the top sensing layer responded 0.24 s faster than the bottom sensing layer. A synthetic biologically-inspired skin such as this will be useful for enhancing the functionality of prosthetic limbs through tactile feedback.

  3. Effects of hand posture on preparatory control processes and sensory modulations in tactile-spatial attention.

    Science.gov (United States)

    Eimer, Martin; Forster, Bettina; Fieger, Anne; Harbich, Stefanie

    2004-03-01

    Event-related brain potentials (ERPs) were measured to investigate spatial coordinate systems involved in the control of preparatory tactile-spatial orienting, and in subsequent attentional modulations of somatosensory processing. On each trial, a visual precue directed attention to the left or right hand, where infrequent tactile targets had to be detected. Hands were positioned either close together or wide apart. ERPs were recorded in the cue-target interval and in response to attended and unattended tactile non-targets. A frontal anterior directing attention negativity (ADAN) and a posterior late directing attention positivity (LDAP) were elicited in the cue-target interval contralateral to the direction of an attentional shift. The ADAN was unaffected by hand posture, but the LDAP was attenuated when hands were close together. N140 amplitudes were enhanced in response to tactile stimuli presented to the attended hand, and this effect was more pronounced when hands were wide apart. ADAN and LDAP are linked to separable anterior and posterior attentional control systems, which use coordinate systems based on somatotopic and external space, respectively. Effects of spatial attention on somatosensory stimulus processing are affected by variations in body posture. Our results demonstrate that representations of body locations in external space play a central role in the control of tactile attention.

  4. Testing Tactile Masking between the Forearms.

    Science.gov (United States)

    D'Amour, Sarah; Harris, Laurence R

    2016-02-10

    Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, usually using stimuli that are close together to reveal local interactions. Masking effects have also been demonstrated in which a tactile stimulus alters the perception of a touch at a distant location. Such effects can provide insight into how components of the body's representations in the brain may be linked. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at corresponding contralateral locations. To explore the matching of corresponding points across the body, we can measure the spatial tuning and effect of posture on contralateral masking. Careful controls are required to rule out direct effects of the remote stimulus, for example by mechanical transmission, and also attention effects in which thresholds may be altered by the participant's attention being drawn away from the stimulus of interest. The use of this technique is beneficial as a behavioural measure for exploring which parts of the body are functionally connected and whether the two sides of the body interact in a somatotopic representation. This manuscript describes a behavioural protocol that can be used for studying contralateral tactile masking.

  5. Tactile Sensory Dysfunction in Children with ADHD

    Directory of Open Access Journals (Sweden)

    Ahmad Ghanizadeh

    2008-01-01

    Full Text Available Objectives: While a group of children with ADHD may have normal behavioral responses to sensory stimuli, another group may be hyperreactive. The aim of this survey was studying association of tactile sensory responsivity with co-morbidity of oppositional defiant disorder (ODD symptoms, subtypes of ADHD, and gender in children with ADHD.

  6. Tactile maze solving in congenitally blind individuals

    DEFF Research Database (Denmark)

    Gagnon, Léa; Kupers, Ron; Schneider, Fabien C

    2010-01-01

    and environmental cues such as temperature and echolocation. We hypothesize that by limiting these cues, blind individuals will lose their advantage compared with controls in spatial navigation tasks. We therefore evaluated the performance of blind and sighted individuals in small-scale, tactile multiple T mazes...

  7. The topography of tactile learning in humans.

    Science.gov (United States)

    Harris, J A; Harris, I M; Diamond, M E

    2001-02-01

    The spatial distribution of learned information within a sensory system can shed light on the brain mechanisms of sensory-perceptual learning. It has been argued that tactile memories are stored within a somatotopic framework in monkeys and rats but within a widely distributed network in humans. We have performed experiments to reexamine the spread of tactile learning across the fingertips. In all experiments, subjects were trained to use one fingertip to discriminate between two stimuli. Experiment 1 required identification of vibration frequency, experiment 2 punctate pressure, and experiment 3 surface roughness. After learning to identify the stimuli reliably, subjects were tested with the trained fingertip, its first and second neighbors on the same hand, and the three corresponding fingertips on the opposite hand. As expected, for all stimulus types, subjects showed retention of learning with the trained fingertip. However, the transfer beyond the trained fingertip varied according to the stimulus type. For vibration, learning did not transfer to other fingertips. For both pressure and roughness stimuli, there was limited transfer, dictated by topographic distance; subjects performed well with the first neighbor of the trained finger and with the finger symmetrically opposite the trained one. These results indicate that tactile learning is organized within a somatotopic framework, reconciling the findings in humans with those in other species. The differential distribution of tactile memory according to stimulus type suggests that the information is stored in stimulus-specific somatosensory cortical fields, each characterized by a unique receptive field organization, feature selectivity, and callosal connectivity.

  8. Unmyelinated Tactile Cutaneous Nerves Signal Erotic Sensations

    NARCIS (Netherlands)

    Jönsson, Emma H; Backlund Wasling, Helena; Wagnbeck, Vicktoria; Dimitriadis, Menelaos; Georgiadis, Janniko R; Olausson, Håkan; Croy, Ilona

    IntroductionIntrapersonal touch is a powerful tool for communicating emotions and can among many things evoke feelings of eroticism and sexual arousal. The peripheral neural mechanisms of erotic touch signaling have been less studied. C tactile afferents (unmyelinated low-threshold

  9. Whisker encoding of mechanical events during active tactile exploration

    Directory of Open Access Journals (Sweden)

    Yves eBoubenec

    2012-11-01

    Full Text Available Rats use their whiskers to extract a wealth of information about their immediate environment, such as the shape, position or texture of an object. The information is conveyed to mechanoreceptors located within the whisker follicle in the form of a sequence of whisker deflections induced by the whisker/object contact interaction. How the whiskers filter and shape the mechanical information and effectively participate in the coding of tactile features remains an open question to date. In the present article, a biomechanical model was developed that provides predictions of the whisker dynamics during active tactile exploration, amenable to quantitative experimental comparison. This model is based on a decomposition of the whisker profile into a slow, quasi-static sequence and rapid resonant small-scale vibrations. It was applied to the typical situation of a rat whisking across an object. Having derived the quasi-static sequence of whisker deformation, the resonant properties of the whisker were analyzed, taking into account the boundary conditions imposed by the whisker/surface contact. We then focused on two elementary mechanical events that are expected to trigger neural responses, namely (i the whisker/object first contact and (ii the whisker detachment from the object. Both events were found to trigger a deflection wave propagating upward to the mystacial pad at constant velocity of 3-5m/s. This yielded a characteristic mechanical signature at the whisker base, in the form of a large peak of negative curvature occurring 4ms after the event was triggered. The dependence in amplitude and lag of this mechanical signal with the main contextual parameters (such as radial or angular distance was investigated. The model was validated experimentally by comparing its predictions to high-speed video recordings of shock-induced whisker deflections performed on anesthetized rats. The consequences of these results on possible tactile encoding schemes are

  10. Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults.

    Directory of Open Access Journals (Sweden)

    Jonathan T W Schubert

    Full Text Available Task demands modulate tactile localization in sighted humans, presumably through weight adjustments in the spatial integration of anatomical, skin-based, and external, posture-based information. In contrast, previous studies have suggested that congenitally blind humans, by default, refrain from automatic spatial integration and localize touch using only skin-based information. Here, sighted and congenitally blind participants localized tactile targets on the palm or back of one hand, while ignoring simultaneous tactile distractors at congruent or incongruent locations on the other hand. We probed the interplay of anatomical and external location codes for spatial congruency effects by varying hand posture: the palms either both faced down, or one faced down and one up. In the latter posture, externally congruent target and distractor locations were anatomically incongruent and vice versa. Target locations had to be reported either anatomically ("palm" or "back" of the hand, or externally ("up" or "down" in space. Under anatomical instructions, performance was more accurate for anatomically congruent than incongruent target-distractor pairs. In contrast, under external instructions, performance was more accurate for externally congruent than incongruent pairs. These modulations were evident in sighted and blind individuals. Notably, distractor effects were overall far smaller in blind than in sighted participants, despite comparable target-distractor identification performance. Thus, the absence of developmental vision seems to be associated with an increased ability to focus tactile attention towards a non-spatially defined target. Nevertheless, that blind individuals exhibited effects of hand posture and task instructions in their congruency effects suggests that, like the sighted, they automatically integrate anatomical and external information during tactile localization. Moreover, spatial integration in tactile processing is, thus, flexibly

  11. Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults.

    Science.gov (United States)

    Schubert, Jonathan T W; Badde, Stephanie; Röder, Brigitte; Heed, Tobias

    2017-01-01

    Task demands modulate tactile localization in sighted humans, presumably through weight adjustments in the spatial integration of anatomical, skin-based, and external, posture-based information. In contrast, previous studies have suggested that congenitally blind humans, by default, refrain from automatic spatial integration and localize touch using only skin-based information. Here, sighted and congenitally blind participants localized tactile targets on the palm or back of one hand, while ignoring simultaneous tactile distractors at congruent or incongruent locations on the other hand. We probed the interplay of anatomical and external location codes for spatial congruency effects by varying hand posture: the palms either both faced down, or one faced down and one up. In the latter posture, externally congruent target and distractor locations were anatomically incongruent and vice versa. Target locations had to be reported either anatomically ("palm" or "back" of the hand), or externally ("up" or "down" in space). Under anatomical instructions, performance was more accurate for anatomically congruent than incongruent target-distractor pairs. In contrast, under external instructions, performance was more accurate for externally congruent than incongruent pairs. These modulations were evident in sighted and blind individuals. Notably, distractor effects were overall far smaller in blind than in sighted participants, despite comparable target-distractor identification performance. Thus, the absence of developmental vision seems to be associated with an increased ability to focus tactile attention towards a non-spatially defined target. Nevertheless, that blind individuals exhibited effects of hand posture and task instructions in their congruency effects suggests that, like the sighted, they automatically integrate anatomical and external information during tactile localization. Moreover, spatial integration in tactile processing is, thus, flexibly adapted by top

  12. The Design and Characterization of a Flexible Tactile Sensing Array for Robot Skin.

    Science.gov (United States)

    Ji, Zhangping; Zhu, Hui; Liu, Huicong; Liu, Nan; Chen, Tao; Yang, Zhan; Sun, Lining

    2016-11-25

    In this study, a flexible tactile sensing array based on a capacitive mechanism was designed, fabricated, and characterized for sensitive robot skin. A device with 8 × 8 sensing units was composed of top and bottom flexible polyethyleneterephthalate (PET) substrates with copper (Cu) electrodes, a polydimethylsiloxane (PDMS) dielectric layer, and a bump contact layer. Four types of microstructures (i.e., pyramids and V-shape grooves) atop a PDMS dielectric layer were well-designed and fabricated to enhance tactile sensitivity. The optimal sensing unit achieved a high sensitivity of 35.9%/N in a force range of 0-1 N. By incorporating a tactile feedback control system, the flexible sensing array as the sensitive skin of a robotic manipulator demonstrated a potential capability of robotic obstacle avoidance.

  13. Fundamental study on formulation design of skin care products by modeling of tactile sensation.

    Science.gov (United States)

    Akiyama, Yoko; Mishima, Fumihito; Nishijima, Shigehiro

    2013-01-01

    The objective of this study is to construct a method to quantify and formulate the human tactile sensation. We have tried to indicate the sensory scores of tactile sensation as a combination of the physical values of skin care products. Consequently, the extracted principle factors of the sensory properties could be related to the physical values by multiple regression analysis. For the next step, we investigated the physical mechanism of tactile sensation, and proposed a method to formulate the sensory properties. A method to formulate the sensory properties of skin care products was constructed based on the relation between sensory values, principal factors, physical values and composition. The method was verified by sensory evaluation.

  14. Research on the Application of Tactile Materials to Design and Printing of Books

    Directory of Open Access Journals (Sweden)

    Wang Yuanyuan

    2016-01-01

    Full Text Available China is a country with the most abundant forms of traditional books, and the evolution of book forms has special material characteristics. The Paper meets the demands of people on multi-sensory stimulation and spiritual experience not only through sense of touch taken as one of human body’s multiple senses, but also through analyzing and researching the tactile materials generated based on the sense of touch and discussing how the tactile materials change the single visual experience of traditional paper media. Unique emotional experience and interactive experience brought by the tactile materials are the future book development direction. Through discussing application to contemporary culture and design thinking and introspection and more profoundly understanding the cultural connotation and the artistic value of the books, a newer way of development is provided for future development of paper books.

  15. Risk prediction and impaired tactile sensory perception among cancer patients during chemotherapy

    Directory of Open Access Journals (Sweden)

    Ana Carolina Lima Ramos Cardoso

    2018-01-01

    Full Text Available ABSTRACT Objectives: to estimate the prevalence of impaired tactile sensory perception, identify risk factors, and establish a risk prediction model among adult patients receiving antineoplastic chemotherapy. Method: historical cohort study based on information obtained from the medical files of 127 patients cared for in the cancer unit of a private hospital in a city in Minas Gerais, Brazil. Data were analyzed using descriptive and bivariate statistics, with survival and multivariate analysis by Cox regression. Results: 57% of the 127 patients included in the study developed impaired tactile sensory perception. The independent variables that caused significant impact, together with time elapsed from the beginning of treatment up to the onset of the condition, were: bone, hepatic and regional lymph node metastases; alcoholism; palliative chemotherapy; and discomfort in lower limbs. Conclusion: impaired tactile sensory perception was common among adult patients during chemotherapy, indicating the need to implement interventions designed for early identification and treatment of this condition.

  16. Design and realization of a tactile switches module with capacitive sensing method implemented with a microcontroller

    Directory of Open Access Journals (Sweden)

    Lorenzo Capineri

    2016-08-01

    Full Text Available The aim of this research project is the architecture and the design of an electronic system for controlling domestic tactile switches to be integrated into a home automation system based on the KNX standard. All the steps that led to the fulfillment of the finished prototype are reported, from the study and design of the capacitive tactile sensors and the electronic control board according to the specifications imposed by KNX standard. The touch event detection is reached as a trade-off with the footprint requirements of the switch. Experimental results of the fabricated prototype are presented to demonstrate the feasibility of this device.

  17. Integration of anatomical and external response mappings explains crossing effects in tactile localization: A probabilistic modeling approach.

    Science.gov (United States)

    Badde, Stephanie; Heed, Tobias; Röder, Brigitte

    2016-04-01

    To act upon a tactile stimulus its original skin-based, anatomical spatial code has to be transformed into an external, posture-dependent reference frame, a process known as tactile remapping. When the limbs are crossed, anatomical and external location codes are in conflict, leading to a decline in tactile localization accuracy. It is unknown whether this impairment originates from the integration of the resulting external localization response with the original, anatomical one or from a failure of tactile remapping in crossed postures. We fitted probabilistic models based on these diverging accounts to the data from three tactile localization experiments. Hand crossing disturbed tactile left-right location choices in all experiments. Furthermore, the size of these crossing effects was modulated by stimulus configuration and task instructions. The best model accounted for these results by integration of the external response mapping with the original, anatomical one, while applying identical integration weights for uncrossed and crossed postures. Thus, the model explained the data without assuming failures of remapping. Moreover, performance differences across tasks were accounted for by non-individual parameter adjustments, indicating that individual participants' task adaptation results from one common functional mechanism. These results suggest that remapping is an automatic and accurate process, and that the observed localization impairments in touch result from a cognitively controlled integration process that combines anatomically and externally coded responses.

  18. Dopaminergic influences on changes in human tactile acuity induced by tactile coactivation.

    Science.gov (United States)

    Bliem, Barbara; Frombach, Elke; Ragert, Patrick; Knossalla, Frauke; Woitalla, Dirk; Tegenthoff, Martin; Dinse, Hubert R

    2007-07-01

    As shown in animal experiments, dopaminergic mechanisms participate in N-methyl-D-aspartate (NMDA) receptor-dependent neuroplasticity. Dopamine is thought to play a similar role in humans, where it influences learning and memory. Here, we tested the dopaminergic action on learning in the tactile domain. To induce tactile non-associative learning, we applied a tactile coactivation protocol, which is known to improve tactile two-point discrimination of the stimulated finger. We studied the influence of a single oral dose of levodopa (25, 50, 100, 250 or 350 mg) administered preceding the coactivation protocol on changes in tactile performance in different groups of subjects. In addition, 3 x 100 mg levodopa was administered over a time period of 3 h in another group. Under placebo conditions, tactile two-point discrimination was improved on the coactivated index finger. Similar improvement was found when 25, 50 and 250 mg levodopa was applied. On the contrary, tactile improvement was completely eliminated by 1 x 100 and 3 x 100 mg levodopa. No drug effects were found on the left index finger indicating that the drug had no effect on performance per se. In contrast to previous findings in the motor and speech domain, we found that the administration of levodopa exerts either no or even negative effects on non-associative learning in the human somatosensory system. Whenever levodopa is used in neurorehabilitative context, it has to be kept in mind that beneficial effects in the motor or speech domain cannot be easily generalized to other systems.

  19. GelSight: High-Resolution Robot Tactile Sensors for Estimating Geometry and Force

    Directory of Open Access Journals (Sweden)

    Wenzhen Yuan

    2017-11-01

    Full Text Available Tactile sensing is an important perception mode for robots, but the existing tactile technologies have multiple limitations. What kind of tactile information robots need, and how to use the information, remain open questions. We believe a soft sensor surface and high-resolution sensing of geometry should be important components of a competent tactile sensor. In this paper, we discuss the development of a vision-based optical tactile sensor, GelSight. Unlike the traditional tactile sensors which measure contact force, GelSight basically measures geometry, with very high spatial resolution. The sensor has a contact surface of soft elastomer, and it directly measures its deformation, both vertical and lateral, which corresponds to the exact object shape and the tension on the contact surface. The contact force, and slip can be inferred from the sensor’s deformation as well. Particularly, we focus on the hardware and software that support GelSight’s application on robot hands. This paper reviews the development of GelSight, with the emphasis in the sensing principle and sensor design. We introduce the design of the sensor’s optical system, the algorithm for shape, force and slip measurement, and the hardware designs and fabrication of different sensor versions. We also show the experimental evaluation on the GelSight’s performance on geometry and force measurement. With the high-resolution measurement of shape and contact force, the sensor has successfully assisted multiple robotic tasks, including material perception or recognition and in-hand localization for robot manipulation.

  20. A New Dynamic Tactile Display for Reconfigurable Braille: Implementation and Tests

    Directory of Open Access Journals (Sweden)

    Paolo eMotto Ros

    2014-04-01

    Full Text Available Different tactile interfaces have been proposed to represent either text (braille or, in a few cases, tactile large-area screens as replacements for visual displays. None of the implementations so far can be customized to match users preferences, perceptual differences and skills. Optimal choices in these respects are still debated; we approach a solution by designing a flexible device allowing the user to choose key parameters of tactile transduction.We present here a new dynamic tactile display, a 8×8 matrix of plastic pins based on well-established and reliable piezoelectric technology to offer high resolution (pin gap 0.7 mm as well as tunable strength of the pins displacement, and refresh rate up to 50 s-1. It can reproduce arbitrary patterns, allowing it to serve the dual purpose of providing, depending on contingent user needs, tactile rendering of non-character information, and reconfigurable braille rendering. Given the relevance of the latter functionality for the expected average user, we considered testing braille encoding by volunteers a benchmark of primary importance. Tests were performed to assess the acceptance and usability with minimal training, and to check whether the offered flexibility was indeed perceived by the subject as an added value compared to conventional braille devices. Different mappings between braille dots and actual tactile pins were implemented to match user needs.Performances of eight experienced braille readers were defined as the fraction of correct identifications of rendered content. Different information contents were tested (median performance on random strings, words, sentences identification was about 75%, 85%, 98%, respectively, with a significant increase, p< 0.01, obtaining statistically significant improvements in performance during the tests (p< 0.05. Experimental results, together with qualitative ratings provided by the subjects, show a good acceptance and the effectiveness of the proposed

  1. Development of CMOS MEMS inductive type tactile sensor with the integration of chrome steel ball force interface

    Science.gov (United States)

    Yeh, Sheng-Kai; Chang, Heng-Chung; Fang, Weileun

    2018-04-01

    This study presents an inductive tactile sensor with a chrome steel ball sensing interface based on the commercially available standard complementary metal–oxide–semiconductor (CMOS) process (the TSMC 0.18 µm 1P6M CMOS process). The tactile senor has a deformable polymer layer as the spring of the device and no fragile suspended thin film structures are required. As a tactile force is applied on the chrome steel ball, the polymer would deform. The distance between the chrome steel ball and the sensing coil would changed. Thus, the tactile force can be detected by the inductance change of the sensing coil. In short, the chrome steel ball acts as a tactile bump as well as the sensing interface. Experimental results show that the proposed inductive tactile sensor has a sensing range of 0–1.4 N with a sensitivity of 9.22(%/N) and nonlinearity of 2%. Preliminary wireless sensing test is also demonstrated. Moreover, the influence of the process and material issues on the sensor performances have also been investigated.

  2. Effects of Tactile Sensations during Finger Painting on Mindfulness, Emotions, and Scope of Attention

    Science.gov (United States)

    Stanko-Kaczmarek, Maja; Kaczmarek, Lukasz D.

    2016-01-01

    Research has shown that creative performance, such as painting, influences affective and cognitive processes. Yet little is known about how tactile sensations experienced during painting determine what individuals feel and how they think while they create. Based on prior research, finger painting (compared to brush painting) was expected to…

  3. Sensor chip and apparatus for tactile and/or flow sensing

    Science.gov (United States)

    Liu, Chang (Inventor); Chen, Jack (Inventor); Engel, Jonathan (Inventor)

    2009-01-01

    A sensor chip, comprising a flexible, polymer-based substrate, and at least one microfabricated sensor disposed on the substrate and including a conductive element. The at least one sensor comprises at least one of a tactile sensor and a flow sensor. Other embodiments of the present invention include sensors and/or multi-modal sensor nodes.

  4. AWARENESS: Tactility and Experience as Transformational Strategy

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Bang, Anne Louise; Locher, Laura

    2015-01-01

    with users. By employing participatory methods in the field of fashion and textiles, we seek to develop an alternative transformational strategy that may further the design of products and services for a more sustainable future. In the initial theoretical section, we define tactile sensibility, which...... discussion on two experiments conducted as part of the Awareness Project. The outcome of the study shows new ways of establishing dialogue between users and designers, as well as furthering reflection and verbalization of areas within the perception of textile and fashion products that are often considered......The Awareness Project investigates the following question: Can dialogue tools that challenge tactile competencies support the development of fashion and textile design in a sustainable direction? In this article, we pay special attention to user engagement and design education and discuss...

  5. Remote Tactile Displays for Future Soldiers

    Science.gov (United States)

    2007-05-01

    organization of the body that may be related to the amount of sensory cortex sub-serving the loci in question. 6 Later work by Craig (1985...side, Braille readers learn to rapidly perceive and process what they touch quite differently than most, showing unique activity in the visual cortex ...weapons ( M4 ). After a short training session with the tactile systems, each Soldier completed the static and dynamic tests three times, once with each

  6. Enhanced tactile encoding and memory recognition in congenital blindness.

    Science.gov (United States)

    D'Angiulli, Amedeo; Waraich, Paul

    2002-06-01

    Several behavioural studies have shown that early-blind persons possess superior tactile skills. Since neurophysiological data show that early-blind persons recruit visual as well as somatosensory cortex to carry out tactile processing (cross-modal plasticity), blind persons' sharper tactile skills may be related to cortical re-organisation resulting from loss of vision early in their life. To examine the nature of blind individuals' tactile superiority and its implications for cross-modal plasticity, we compared the tactile performance of congenitally totally blind, low-vision and sighted children on raised-line picture identification test and re-test, assessing effects of task familiarity, exploratory strategy and memory recognition. What distinguished the blind from the other children was higher memory recognition and higher tactile encoding associated with efficient exploration. These results suggest that enhanced perceptual encoding and recognition memory may be two cognitive correlates of cross-modal plasticity in congenital blindness.

  7. Tactile display on the remaining hand for unilateral hand amputees

    Directory of Open Access Journals (Sweden)

    Li Tao

    2016-09-01

    Full Text Available Human rely profoundly on tactile feedback from fingertips to interact with the environment, whereas most hand prostheses used in clinics provide no tactile feedback. In this study we demonstrate the feasibility to use a tactile display glove that can be worn by a unilateral hand amputee on the remaining healthy hand to display tactile feedback from a hand prosthesis. The main benefit is that users could easily distinguish the feedback for each finger, even without training. The claimed advantage is supported by preliminary tests with healthy subjects. This approach may lead to the development of effective and affordable tactile display devices that provide tactile feedback for individual fingertip of hand prostheses.

  8. Research for improved flexible tactile sensor sensitivity

    International Nuclear Information System (INIS)

    Yun, Hae Yong; Kim, Ho Chan; Lee, In Hwan

    2015-01-01

    With the development of robotic technologies, in recent years these technologies have been applied to multidisciplinary fields of study. To operate similarly to a human being, many robot technologies require devices that can receive exterior stimulus, temperature, visual data, and the sense of smell, etc. The robot's hand needs sensor devices that can receive exterior stimuli in order to operate similarly to human skin. The flexible tactile sensor for the robot has to be manufactured to have a shape similar to the shape of human skin. The research studied the development of a system and materials that will enable exterior stimuli to be received effectively. This research used carbon nano tube as a material. Carbon nano tube is used because it has a high electrical conductivity and outstanding mechanical characteristics. In addition, the two composite Materials are used to improve the stimulation sensitivity at different rates, the flexible tactile sensor to measure the sensitivity. Using 3D printing technology, the fabrication of a flexible tactile sensor system is introduced.

  9. Research for improved flexible tactile sensor sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hae Yong; Kim, Ho Chan [Andong National University, Andong (Korea, Republic of); Lee, In Hwan [Chungbuk National University, Chungju (Korea, Republic of)

    2015-11-15

    With the development of robotic technologies, in recent years these technologies have been applied to multidisciplinary fields of study. To operate similarly to a human being, many robot technologies require devices that can receive exterior stimulus, temperature, visual data, and the sense of smell, etc. The robot's hand needs sensor devices that can receive exterior stimuli in order to operate similarly to human skin. The flexible tactile sensor for the robot has to be manufactured to have a shape similar to the shape of human skin. The research studied the development of a system and materials that will enable exterior stimuli to be received effectively. This research used carbon nano tube as a material. Carbon nano tube is used because it has a high electrical conductivity and outstanding mechanical characteristics. In addition, the two composite Materials are used to improve the stimulation sensitivity at different rates, the flexible tactile sensor to measure the sensitivity. Using 3D printing technology, the fabrication of a flexible tactile sensor system is introduced.

  10. Feasibility study of patient motion monitoring using tactile array sensor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Ho; Kang, Seong Hee; Kim, Dong Su; Cho, Min Seok; Kim, Kyeong Hyeon; Suh, Tae Suk [Dept. of Biomedical Engineering, Research Institute of Biomedical Engineering, the Catholic University of Korea, Seoul (Korea, Republic of); Kim, Si Yong [Dept. of Radiation Oncology, Virginia Commonwealth University, Richmond (United States)

    2014-11-15

    The aim of this study is to evaluate patient pretreatment set-up error and intra-fraction motion using the tactile array sensors (Pressure Profile Systems Inc, Los Angeles, CA) which could measure distributed pressure profiles along the contacting surface and to check a feasibility of the sensor (tactile array sensor) in the patient motion monitoring. Laser alignment and optical camera based monitoring system are very useful for reduce patient set-up error but these systems could not monitor the blind area like patient's back position. Actually after patient alignment using laser or optical monitoring system, it was assumed that there is no error in the patient's back position (pressure profile distribution). But if an error occurs in the patient's back position, it will affect the radiation therapy accuracy. In spite of optical motion monitoring or using the immobilization tool, distributed pressure profiles of patient's back position was changed during inter and intra-fraction. For more accurate patient set-up, blind area (patient's back) monitoring was necessary. We expect that the proposed method will be very useful for make up for the weakness of optical monitoring method.

  11. Tactile Studio, artigianato digitale al servizio dell’accessibilità

    OpenAIRE

    Riccardo Leone; Philippe Moreau

    2017-01-01

    Tactile Studio is a design agency for universal design in arts and culture. Tactile experiences are essential for people with visual impairm ents and gr eatly assist many people with cognitive disabilities. Tactile experiences should be included in every exhibition. Children, older adults, people with language diff iculties or fr om diff erent cultural backgr ounds..To name an audience who will not benefit fr om these designs is impossible. Pioneers in France, the nation's top museums have en...

  12. Tactile Roughness Perception in the Presence of Olfactory and Trigeminal Stimulants.

    NARCIS (Netherlands)

    Koijck, Lara A.; Toet, Alexander; van Erp, Johannes Bernardus Fransiscus

    2015-01-01

    Previous research has shown that odorants consistently evoke associations with textures and their tactile properties like smoothness and roughness. Also, it has been observed that olfaction can modulate tactile perception. We therefore hypothesized that tactile roughness perception may be biased

  13. Tactile roughness perception in the presence of olfactory and trigeminal stimulants

    NARCIS (Netherlands)

    Koijck, L.A.; Toet, A.; Erp, J.B.F. van

    2015-01-01

    Previous research has shown that odorants consistently evoke associations with textures and their tactile properties like smoothness and roughness. Also, it has been observed that olfaction can modulate tactile perception. We therefore hypothesized that tactile roughness perception may be biased

  14. A Modified Tactile Brush Algorithm for Complex Touch Gestures

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, Eric [Texas A& M University

    2015-01-01

    Several researchers have investigated phantom tactile sensation (i.e., the perception of a nonexistent actuator between two real actuators) and apparent tactile motion (i.e., the perception of a moving actuator due to time delays between onsets of multiple actuations). Prior work has focused primarily on determining appropriate Durations of Stimulation (DOS) and Stimulus Onset Asynchronies (SOA) for simple touch gestures, such as a single finger stroke. To expand upon this knowledge, we investigated complex touch gestures involving multiple, simultaneous points of contact, such as a whole hand touching the arm. To implement complex touch gestures, we modified the Tactile Brush algorithm to support rectangular areas of tactile stimulation.

  15. Acquisition of a bodily-tactile language as first language

    DEFF Research Database (Denmark)

    Ask Larsen, Flemming

    2013-01-01

    Language acquisition in the bodily-tactile modality is difficult to understand, describe, and support. This chapter advocates a reinterpretation of the gestural and idiosyncratic bodily-tactile communication of people with congenital deafblindness (CDB) in terms of early language acquisition...... towards Tactile Sign Language (TSL). The access to participation in complex TSL culture is crucial for language acquisition. We already know how to transfer the patterns of social interaction into the bodily-tactile modality. This is the fundation on which to build actual linguistic participation. TSL...

  16. Autism spectrum disorder in the scope of tactile processing

    Directory of Open Access Journals (Sweden)

    Mark Mikkelsen

    2018-01-01

    Full Text Available Sensory processing abnormalities are among the most common behavioral phenotypes seen in autism spectrum disorder (ASD, typically characterized by either over- or under-responsiveness to stimulation. In this review, we focus on tactile processing dysfunction in ASD. We firstly review clinical studies wherein sensitivity to tactile stimuli has traditionally been assessed by self-, parent- and experimenter-reports. We also discuss recent investigations using psychophysical paradigms that gauge individual tactile thresholds. These more experimentally rigorous studies allow for more objective assessments of tactile abnormalities in ASD. However, little is understood about the neurobiological mechanisms underlying these abnormalities, or the link between tactile abnormalities and ASD symptoms. Neurobiological research that has been conducted has pointed toward dysfunction in the excitation/inhibition balance of the central nervous system of those with ASD. This review covers recent efforts that have investigated tactile dysfunction in ASD from clinical and behavioral perspectives, and some of the efforts to link these to neurobiology. On the whole, findings are inconsistent, which can be ascribed to the subjectivity of clinical assessments, the heterogeneity of ASD cohorts, and the diversity of tactile sensitivity measures. Future endeavors into understanding tactile processing differences in ASD will greatly benefit from controlled experiments driven by neurobiological hypotheses. Keywords: Autism spectrum disorder, Psychophysics, Review, Touch, Somatosensory, Tactile processing

  17. A Novel Tactile Sensor with Electromagnetic Induction and Its Application on Stick-Slip Interaction Detection

    Directory of Open Access Journals (Sweden)

    Yanjie Liu

    2016-03-01

    Full Text Available Real-time detection of contact states, such as stick-slip interaction between a robot and an object on its end effector, is crucial for the robot to grasp and manipulate the object steadily. This paper presents a novel tactile sensor based on electromagnetic induction and its application on stick-slip interaction. An equivalent cantilever-beam model of the tactile sensor was built and capable of constructing the relationship between the sensor output and the friction applied on the sensor. With the tactile sensor, a new method to detect stick-slip interaction on the contact surface between the object and the sensor is proposed based on the characteristics of friction change. Furthermore, a prototype was developed for a typical application, stable wafer transferring on a wafer transfer robot, by considering the spatial magnetic field distribution and the sensor size according to the requirements of wafer transfer. The experimental results validate the sensing mechanism of the tactile sensor and verify its feasibility of detecting stick-slip on the contact surface between the wafer and the sensor. The sensing mechanism also provides a new approach to detect the contact state on the soft-rigid surface in other robot-environment interaction systems.

  18. A Review of Smart Materials in Tactile Actuators for Information Delivery

    Directory of Open Access Journals (Sweden)

    Xin Xie

    2017-12-01

    Full Text Available As the largest organ in the human body, the skin provides the important sensory channel for humans to receive external stimulations based on touch. By the information perceived through touch, people can feel and guess the properties of objects, like weight, temperature, textures, and motion, etc. In fact, those properties are nerve stimuli to our brain received by different kinds of receptors in the skin. Mechanical, electrical, and thermal stimuli can stimulate these receptors and cause different information to be conveyed through the nerves. Technologies for actuators to provide mechanical, electrical or thermal stimuli have been developed. These include static or vibrational actuation, electrostatic stimulation, focused ultrasound, and more. Smart materials, such as piezoelectric materials, carbon nanotubes, and shape memory alloys, play important roles in providing actuation for tactile sensation. This paper aims to review the background biological knowledge of human tactile sensing, to give an understanding of how we sense and interact with the world through the sense of touch, as well as the conventional and state-of-the-art technologies of tactile actuators for tactile feedback delivery.

  19. Decoding covert somatosensory attention by a BCI system calibrated with tactile sensation.

    Science.gov (United States)

    Yao, Lin; Sheng, Xinjun; Mrachacz-Kersting, Natalie; Zhu, Xiangyang; Farina, Dario; Jiang, Ning

    2017-10-12

    We propose a novel calibration strategy to facilitate the decoding of covert somatosensory attention by exploring the oscillatory dynamics induced by tactile sensation. It was hypothesized that the similarity of the oscillatory pattern between stimulation sensation (SS, real sensation) and somatosensory attentional orientation (SAO) provides a way to decode covert somatic attention. Subjects were instructed to sense the tactile stimulation, which was applied to the left (SS-L) or the right (SS-R) wrist. The BCI system was calibrated with the sensation data and then applied for online SAO decoding. Both SS and SAO showed oscillatory activation concentrated on the contralateral somatosensory hemisphere. Offline analysis showed that the proposed calibration method led to greater accuracy than the traditional calibration method based on SAO only. This is confirmed by online experiments, where the online accuracy on 15 subjects was %, with 12 subjects >70% and 4 subject >90%. By integrating the stimulus-induced oscillatory dynamics from sensory cortex, covert somatosensory attention can be reliably decoded by a BCI system calibrated with tactile sensation. Indeed, real tactile sensation is more consistent during calibration than SAO. This brain-computer interfacing approach may find application for stroke and completely locked-in patients with preserved somatic sensation.

  20. Modeling and optimal design of an optical MEMS tactile sensor for use in robotically assisted surgery

    Science.gov (United States)

    Ahmadi, Roozbeh; Kalantari, Masoud; Packirisamy, Muthukumaran; Dargahi, Javad

    2010-06-01

    Currently, Minimally Invasive Surgery (MIS) performs through keyhole incisions using commercially available robotic surgery systems. One of the most famous examples of these robotic surgery systems is the da Vinci surgical system. In the current robotic surgery systems like the da Vinci, surgeons are faced with problems such as lack of tactile feedback during the surgery. Therefore, providing a real-time tactile feedback from interaction between surgical instruments and tissue can help the surgeons to perform MIS more reliably. The present paper proposes an optical tactile sensor to measure the contact force between the bio-tissue and the surgical instrument. A model is proposed for simulating the interaction between a flexible membrane and bio-tissue based on the finite element methods. The tissue is considered as a hyperelastic material with the material properties similar to the heart tissue. The flexible membrane is assumed as a thin layer of silicon which can be microfabricated using the technology of Micro Electro Mechanical Systems (MEMS). The simulation results are used to optimize the geometric design parameters of a proposed MEMS tactile sensor for use in robotic surgical systems to perform MIS.

  1. A Finger-Shaped Tactile Sensor for Fabric Surfaces Evaluation by 2-Dimensional Active Sliding Touch

    Directory of Open Access Journals (Sweden)

    Haihua Hu

    2014-03-01

    Full Text Available Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM. The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures.

  2. Supramodal theta, gamma, and sustained fields predict modality-specific modulations of alpha and beta oscillations during visual and tactile working memory

    NARCIS (Netherlands)

    Ede, F.L. van; Jensen, O.; Maris, E.G.G.

    2017-01-01

    Flexible control over currently relevant sensory representations is an essential feature of primate cognition. We investigated the neurophysiological bases of such flexible control in humans during an intermodal working memory task in which participants retained visual or tactile sequences. Using

  3. Tactile perception and working memory in rats and humans.

    Science.gov (United States)

    Fassihi, Arash; Akrami, Athena; Esmaeili, Vahid; Diamond, Mathew E

    2014-02-11

    Primates can store sensory stimulus parameters in working memory for subsequent manipulation, but until now, there has been no demonstration of this capacity in rodents. Here we report tactile working memory in rats. Each stimulus is a vibration, generated as a series of velocity values sampled from a normal distribution. To perform the task, the rat positions its whiskers to receive two such stimuli, "base" and "comparison," separated by a variable delay. It then judges which stimulus had greater velocity SD. In analogous experiments, humans compare two vibratory stimuli on the fingertip. We demonstrate that the ability of rats to hold base stimulus information (for up to 8 s) and their acuity in assessing stimulus differences overlap the performance demonstrated by humans. This experiment highlights the ability of rats to perceive the statistical structure of vibrations and reveals their previously unknown capacity to store sensory information in working memory.

  4. Acoustic Tactile Representation of Visual Information

    Science.gov (United States)

    Silva, Pubudu Madhawa

    Our goal is to explore the use of hearing and touch to convey graphical and pictorial information to visually impaired people. Our focus is on dynamic, interactive display of visual information using existing, widely available devices, such as smart phones and tablets with touch sensitive screens. We propose a new approach for acoustic-tactile representation of visual signals that can be implemented on a touch screen and allows the user to actively explore a two-dimensional layout consisting of one or more objects with a finger or a stylus while listening to auditory feedback via stereo headphones. The proposed approach is acoustic-tactile because sound is used as the primary source of information for object localization and identification, while touch is used for pointing and kinesthetic feedback. A static overlay of raised-dot tactile patterns can also be added. A key distinguishing feature of the proposed approach is the use of spatial sound (directional and distance cues) to facilitate the active exploration of the layout. We consider a variety of configurations for acoustic-tactile rendering of object size, shape, identity, and location, as well as for the overall perception of simple layouts and scenes. While our primary goal is to explore the fundamental capabilities and limitations of representing visual information in acoustic-tactile form, we also consider a number of relatively simple configurations that can be tied to specific applications. In particular, we consider a simple scene layout consisting of objects in a linear arrangement, each with a distinct tapping sound, which we compare to a ''virtual cane.'' We will also present a configuration that can convey a ''Venn diagram.'' We present systematic subjective experiments to evaluate the effectiveness of the proposed display for shape perception, object identification and localization, and 2-D layout perception, as well as the applications. Our experiments were conducted with visually blocked

  5. Tactile multisensing on flexible aluminum nitride.

    Science.gov (United States)

    Petroni, Simona; Guido, Francesco; Torre, Bruno; Falqui, Andrea; Todaro, Maria Teresa; Cingolani, Roberto; De Vittorio, Massimo

    2012-11-21

    The integration of a polycrystalline material such as aluminum nitride (AlN) on a flexible substrate allows the realization of elastic tactile sensors showing both piezoelectricity and significant capacitive variation under normal stress. The application of a normal stress on AlN generates deformation of the flexible substrate on which AlN is grown, which results in strain gradient of the polycrystalline layer. The strain gradient is responsible for an additional polarization described in the literature as the flexoelectric effect, leading to an enhancement of the transduction properties of the material. The flexible AlN is synthesized by sputtering deposition on kapton HN (poly 4,4'-oxydiphenyl pyromellitimide) in a highly oriented crystal structure. High orientation is demonstrated by X-ray diffraction spectra (FWHM = 0.55° of AlN (0002)) and HRTEM. The piezoelectric coefficient d(33) and stress sensitive capacitance are 4.7 ± 0.5 pm V(-1) and 4 × 10(-3) pF kPa(-1), respectively. The parallel plate capacitors realized for tactile sensing present a typical dome shape, very elastic under applied stress and sensitive in the pressure range of interest for robotic applications (10 kPa to 1 MPa). The flexibility of the device finalized for tactile applications is assessed by measuring the sensor capacitance before and after shaping the sensing foil on curved surfaces for 1 hour. Bending does not affect sensor's operation, which exhibits an electrical Q factor as high as 210, regardless of the bending, and a maximum capacitance shift of 0.02%.

  6. Tactile Perception in Adults with Autism: A Multidimensional Psychophysical Study

    Science.gov (United States)

    Cascio, Carissa; McGlone, Francis; Folger, Stephen; Tannan, Vinay; Baranek, Grace; Pelphrey, Kevin A.; Essick, Gregory

    2008-01-01

    Although sensory problems, including unusual tactile sensitivity, are heavily associated with autism, there is a dearth of rigorous psychophysical research. We compared tactile sensation in adults with autism to controls on the palm and forearm, the latter innervated by low-threshold unmyelinated afferents subserving a social/affiliative…

  7. CURRENT STATUS AND DEVELOPMENT PROSPECTS OF TACTILE CARTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Y. G. Poshivailo

    2014-01-01

    Full Text Available The article gives a brief survey of the current state and prospects of tactile cartography development. Some types of adaptive cognitive aids for blind people are considered. The authors share their experience in developing innovative form of cartographic products – tactile audiovisual device.

  8. Beneficial Effects of Tactile Stimulation on Early Development.

    Science.gov (United States)

    Caulfield, Rick

    2000-01-01

    Reviews selected research on the beneficial effects of tactile stimulation on infants. Examines the results of studies with animals, preterm infants, cocaine- and HIV-exposed preterm infants, and normal full-term infants. Briefly discusses caregiving implications and offers suggestions on how caregivers can incorporate tactile stimulation in…

  9. Tactile learning in rodents: Neurobiology and neuropharmacology.

    Science.gov (United States)

    Roohbakhsh, Ali; Shamsizadeh, Ali; Arababadi, Mohammad Kazemi; Ayoobi, Fateme; Fatemi, Iman; Allahtavakoli, Mohammad; Mohammad-Zadeh, Mohammad

    2016-02-15

    Animal models of learning and memory have been the subject of considerable research. Rodents such as mice and rats are nocturnal animals with poor vision, and their survival depends on their sense of touch. Recent reports have shown that whisker somatosensation is the main channel through which rodents collect and process environmental information. This review describes tactile learning in rodents from a neurobiological and neuropharmacological perspective, and how this is involved in memory-related processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Comparative Evaluation of Tactile Sensation by Electrical and Mechanical Stimulation.

    Science.gov (United States)

    Yem, Vibol; Kajimoto, Hiroyuki

    2017-01-01

    An electrotactile display is a tactile interface that provides tactile perception by passing electrical current through the surface of the skin. It is actively used instead of mechanical tactile displays for tactile feedback because of several advantages such as its small and thin size, light weight, and high responsiveness. However, the similarities and differences between these sensations is still not clear. This study directly compares the intensity sensation of electrotactile stimulation to that of mechanical stimulation, and investigates the characteristic sensation of anodic and cathodic stimulation. In the experiment, participants underwent a 30 pps electrotactile stimulus every one second to their middle finger, and were asked to match this intensity by adjusting the intensity of a mechanical tactile stimulus to an index finger. The results showed that anodic stimulation mainly produced vibration sensation, whereas cathodic sensation produced both vibration and pressure sensations. Relatively low pressure sensation was also observed for anodic stimulation but it remains low, regardless of the increasing of electrical intensity.

  11. Sustained maintenance of somatotopic information in brain regions recruited by tactile working memory.

    Science.gov (United States)

    Katus, Tobias; Müller, Matthias M; Eimer, Martin

    2015-01-28

    To adaptively guide ongoing behavior, representations in working memory (WM) often have to be modified in line with changing task demands. We used event-related potentials (ERPs) to demonstrate that tactile WM representations are stored in modality-specific cortical regions, that the goal-directed modulation of these representations is mediated through hemispheric-specific activation of somatosensory areas, and that the rehearsal of somatotopic coordinates in memory is accomplished by modality-specific spatial attention mechanisms. Participants encoded two tactile sample stimuli presented simultaneously to the left and right hands, before visual retro-cues indicated which of these stimuli had to be retained to be matched with a subsequent test stimulus on the same hand. Retro-cues triggered a sustained tactile contralateral delay activity component with a scalp topography over somatosensory cortex contralateral to the cued hand. Early somatosensory ERP components to task-irrelevant probe stimuli (that were presented after the retro-cues) and to subsequent test stimuli were enhanced when these stimuli appeared at the currently memorized location relative to other locations on the cued hand, demonstrating that a precise focus of spatial attention was established during the selective maintenance of tactile events in WM. These effects were observed regardless of whether participants performed the matching task with uncrossed or crossed hands, indicating that WM representations in this task were based on somatotopic rather than allocentric spatial coordinates. In conclusion, spatial rehearsal in tactile WM operates within somatotopically organized sensory brain areas that have been recruited for information storage. Copyright © 2015 Katus et al.

  12. Cognitive and tactile factors affecting human haptic performance in later life.

    Directory of Open Access Journals (Sweden)

    Tobias Kalisch

    Full Text Available BACKGROUND: Vision and haptics are the key modalities by which humans perceive objects and interact with their environment in a target-oriented manner. Both modalities share higher-order neural resources and the mechanisms required for object exploration. Compared to vision, the understanding of haptic information processing is still rudimentary. Although it is known that haptic performance, similar to many other skills, decreases in old age, the underlying mechanisms are not clear. It is yet to be determined to what extent this decrease is related to the age-related loss of tactile acuity or cognitive capacity. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the haptic performance of 81 older adults by means of a cross-modal object recognition test. Additionally, we assessed the subjects' tactile acuity with an apparatus-based two-point discrimination paradigm, and their cognitive performance by means of the non-verbal Raven-Standard-Progressive matrices test. As expected, there was a significant age-related decline in performance on all 3 tests. With the exception of tactile acuity, this decline was found to be more distinct in female subjects. Correlation analyses revealed a strong relationship between haptic and cognitive performance for all subjects. Tactile performance, on the contrary, was only significantly correlated with male subjects' haptic performance. CONCLUSIONS: Haptic object recognition is a demanding task in old age, especially when it comes to the exploration of complex, unfamiliar objects. Our data support a disproportionately higher impact of cognition on haptic performance as compared to the impact of tactile acuity. Our findings are in agreement with studies reporting an increase in co-variation between individual sensory performance and general cognitive functioning in old age.

  13. A Portable Piezoelectric Tactile Terminal for Braille Readers

    Directory of Open Access Journals (Sweden)

    Ramiro Velázquez

    2012-01-01

    Full Text Available This paper introduces a novel concept on reading assistive technologies for the blind: the TactoBook, a system that is able to translate entire electronic books (eBooks to Braille code and to reproduce them in portable electronic Braille terminals. The TactoBook consists of a computer-based translator that converts fast and automatically any eBook into Braille. The Braille version of the eBook is then encrypted as a file and stored in a USB memory drive which is later inserted and reproduced in a compact, lightweight, and highly-portable tactile terminal. In particular, this paper presents a piezoelectric ultrasonic actuation approach to design and implement such portable Braille terminal. Actuating mechanism, design concept, first prototype, and performance results are presented and discussed.

  14. Tactile Digital Video Globes: a New Way to Outreach Oceanography.

    Science.gov (United States)

    Poteau, A.; Claustre, H.; Scheurle, C.; Jessin, T.; Fontana, C.

    2016-02-01

    One objective of the "Ocean Autonomous Observation" team of the Laboratory of Oceanography of Villefranche-sur-mer is to develop new means to outreach our science activities to various audiences. Besides the scientific community, this includes students and targets the general public, school pupils, and stakeholders. In this context, we have acquired a digital video globe with tactile capabilities and we will present here the various applications that we have been developing. A first type of products concerns the visualization of oceanic properties (SST, salinity, density, Chla, O2, NO3, irradiance) by diving from the surface (generally from satellite data) into the Ocean interior (through the use of global data bases, Argo, WOA). In second place, specific applications deal with surface animations allowing highlighting the seasonality of some properties (Chla, SST, ice cover, currents; based on satellite as well as modeling outputs). Finally, we show a variety of applications developed using the tactile functionality of the spherical display. In particular real-time vertical profiles acquired by Bio-Argo floats become directly accessible for the entire open ocean. Such a new tool plus its novel applications has been presented to school children, and to the wider public (at the so-called "fête de la science") as well as to potential sponsors of our science-outreach activities. Their feedback has always been highly positive and encouraging in terms of impact. From the scientists point of view, the use of this new support can easily compete with the classical PowerPoint, is much more attractive and fun and undeniably helps to outreach the various aspects of our pluridisciplinary science.

  15. Neural pathways in tactile object recognition.

    Science.gov (United States)

    Deibert, E; Kraut, M; Kremen, S; Hart, J

    1999-04-22

    To define further the brain regions involved in tactile object recognition using functional MRI (fMRI) techniques. The neural substrates involved in tactile object recognition (TOR) have not been elucidated. Studies of nonhuman primates and humans suggest that basic motor and somatosensory mechanisms are involved at a peripheral level; however, the mechanisms of higher order object recognition have not been determined. The authors investigated 11 normal volunteers utilizing fMRI techniques in an attempt to determine the neural pathways involved in TOR. Each individual performed a behavioral paradigm with the activated condition involving identification of objects by touch, with identification of rough/smooth as the control. Data suggest that in a majority of individuals, TOR involves the calcarine and extrastriatal cortex, inferior parietal lobule, inferior frontal gyrus, and superior frontal gyrus-polar region. TOR may utilize visual systems to access an internal object representation. The parietal cortices and inferior frontal regions may be involved in a concomitant lexical strategy of naming the object being examined. Frontal polar activation likely serves a role in visuospatial working memory or in recognizing unusual representations of objects. Overall, these findings suggest that TOR could involve a network of cortical regions subserving somatosensory, motor, visual, and, at times, lexical processing. The primary finding suggests that in this normal study population, the visual cortices may be involved in the topographic spatial processing of TOR.

  16. The topography of tactile working memory.

    Science.gov (United States)

    Harris, J A; Harris, I M; Diamond, M E

    2001-10-15

    To investigate the contribution of topographically organized brain areas to tactile working memory, we asked human subjects to compare the frequency of two vibrations presented to the same fingertip or to different fingertips. The vibrations ranged from 14 to 24 Hz and were separated by a retention interval of variable length. For intervals memory resides within a topographic framework. As a further test, we performed an experiment in which the two comparison vibrations were presented to the same fingertip but an interference vibration was presented during the retention interval. The interpolated vibration disrupted accuracy most when delivered to the same finger as the comparison vibrations and had progressively less effect when delivered to more distant fingers. We conclude that topographically organized regions of somatosensory cortex contribute to tactile working memory, possibly by holding the memory trace across the retention interval. One stimulus can be accurately compared with the memory of a previous stimulus if they engage overlapping representations, but activation of the common cortical territory by an interpolated stimulus can disrupt the memory trace.

  17. Metacognition of attention during tactile discrimination.

    Science.gov (United States)

    Whitmarsh, Stephen; Oostenveld, Robert; Almeida, Rita; Lundqvist, Daniel

    2017-02-15

    The ability to monitor the success of cognitive processing is referred to as metacognition. Studies of metacognition typically probe post-decision judgments of confidence, showing that we can report on the success of wide range of cognitive processes. Much less is known about our ability to monitor and report on the degree of top-down attention, an ability of paramount importance in tasks requiring sustained attention. However, it has been repeatedly shown that the degree and locus of top-down attention modulates alpha (8-14Hz) power in sensory cortices. In this study we investigated whether self-reported ratings of attention are reflected by sensory alpha power, independent from confidence and task difficulty. Subjects performed a stair-cased tactile discrimination task requiring sustained somatosensory attention. Each discrimination response was followed by a rating of their attention at the moment of stimulation, or their confidence in the discrimination response. MEG was used to estimate trial-by-trial alpha power preceding stimulation. Staircasing of task-difficulty successfully equalized performance between conditions. Both attention and confidence ratings reflected subsequent discrimination performance. Task difficulty specifically influenced confidence ratings. As expected, specifically attention ratings, but not confidence ratings, correlated negatively with contralateral somatosensory alpha power preceding tactile stimuli. Taken together, these results demonstrate that the degree of attention can be subjectively experienced and reported accurately, independent from task difficulty and knowledge about task performance. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Creating and Using Tactile Experience Books for Young Children with Visual Impairments.

    Science.gov (United States)

    Lewis, Sandra; Tolla, Joan

    2003-01-01

    This article explores how tactile experience books can be used to ensure that young children with visual impairments learn to read. It discusses making tactile experience books by collecting artifacts and gluing them to cardboard pages, and the benefits of tactile books. Descriptions of two tactile books are provided. (Contains references.) (CR)

  19. Tactile Experience Shapes Prey-Capture Behavior in Etruscan Shrews

    Directory of Open Access Journals (Sweden)

    Michael eBrecht

    2012-06-01

    Full Text Available A crucial role of tactile experience for the maturation of neural response properties in the somatosensory system is well established, but little is known about the role of tactile experience in the development of tactile behaviors. Here we study how tactile experience affects prey capture behavior in Etruscan shrews, Suncus etruscus. Prey capture in adult shrews is a high-speed behavior that relies on precise attacks guided by tactile Gestalt cues. We studied the role of tactile experience by three different approaches. First, we analyzed the hunting skills of young shrews right after weaning. We found that prey capture in young animals is most but not all aspects similar to that of adults. Second we performed whisker trimming for three to four weeks after birth. Such deprivation resulted in a lasting disruption of prey capture even after whisker re-growth: attacks lacked precise targeting and had a lower success rate. Third, we presented adult shrews with an entirely novel prey species, the giant cockroach. The shape of this roach is very different from the shrew’s normal (cricket prey and the thorax – the preferred point of attack in crickets – is protected a heavy cuticle. Initially shrews attacked giant roaches the same way they attack crickets and targeted the thoracic region. With progressive experience, however, shrews adopted a new attack strategy targeting legs and underside of the roaches while avoiding other body parts. Speed and efficiency of attacks improved. These data suggest that tactile experience shapes prey capture behavior.

  20. Salience of Tactile Cues: An Examination of Tactor Actuator and Tactile Cue Characteristics

    Science.gov (United States)

    2015-08-01

    frequency, intensity, force, location, and duration of the signal. However, these definitions and their associated thresholds, in isolation, are of little...tactile salience composed of 3 core constructs (individual differences, technology, and context) and their interactions. This definition provides an...attention to surrounding landmarks or threat (e.g., flora , fauna) and have hands free for other tasks (e.g., making one’s way, drinking water). When

  1. Audio-Visual, Visuo-Tactile and Audio-Tactile Correspondences in Preschoolers.

    Science.gov (United States)

    Nava, Elena; Grassi, Massimo; Turati, Chiara

    2016-01-01

    Interest in crossmodal correspondences has recently seen a renaissance thanks to numerous studies in human adults. Yet, still very little is known about crossmodal correspondences in children, particularly in sensory pairings other than audition and vision. In the current study, we investigated whether 4-5-year-old children match auditory pitch to the spatial motion of visual objects (audio-visual condition). In addition, we investigated whether this correspondence extends to touch, i.e., whether children also match auditory pitch to the spatial motion of touch (audio-tactile condition) and the spatial motion of visual objects to touch (visuo-tactile condition). In two experiments, two different groups of children were asked to indicate which of two stimuli fitted best with a centrally located third stimulus (Experiment 1), or to report whether two presented stimuli fitted together well (Experiment 2). We found sensitivity to the congruency of all of the sensory pairings only in Experiment 2, suggesting that only under specific circumstances can these correspondences be observed. Our results suggest that pitch-height correspondences for audio-visual and audio-tactile combinations may still be weak in preschool children, and speculate that this could be due to immature linguistic and auditory cues that are still developing at age five.

  2. Preliminary study on piezoresistive and piezoelectric properties of a double-layer soft material for tactile sensing

    Directory of Open Access Journals (Sweden)

    Dan He

    2015-06-01

    Full Text Available This paper describes a double-layer simplified sensor unit based on the interesting electromechanical properties of MWNT mixed by polymer composite and PVDF films, which is envisaged to imitate the distributed tactile receptors of human hands so as to help the disabled to recover the basic tactile perception. This paper shows the fabrication and performance research of such a new piezoelectric-piezoresistive composite material which indicates a promising .application in prosthtic hand.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6454

  3. Distributed neural networks of tactile working memory.

    Science.gov (United States)

    Wang, Liping; Bodner, Mark; Zhou, Yong-Di

    2013-12-01

    Microelectrode recordings of cortical activity in primates performing working memory tasks reveal some cortical neurons exhibiting sustained or graded persistent elevations in firing rate during the period in which sensory information is actively maintained in short-term memory. These neurons are called "memory cells". Imaging and transcranial magnetic stimulation studies indicate that memory cells may arise from distributed cortical networks. Depending on the sensory modality of the memorandum in working memory tasks, neurons exhibiting memory-correlated patterns of firing have been detected in different association cortices including prefrontal cortex, and primary sensory cortices as well. Here we elaborate on neurophysiological experiments that lead to our understanding of the neuromechanisms of working memory, and mainly discuss findings on widely distributed cortical networks involved in tactile working memory. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Review of Recent Inkjet-Printed Capacitive Tactile Sensors

    Directory of Open Access Journals (Sweden)

    Ahmed Salim

    2017-11-01

    Full Text Available Inkjet printing is an advanced printing technology that has been used to develop conducting layers, interconnects and other features on a variety of substrates. It is an additive manufacturing process that offers cost-effective, lightweight designs and simplifies the fabrication process with little effort. There is hardly sufficient research on tactile sensors and inkjet printing. Advancements in materials science and inkjet printing greatly facilitate the realization of sophisticated tactile sensors. Starting from the concept of capacitive sensing, a brief comparison of printing techniques, the essential requirements of inkjet-printing and the attractive features of state-of-the art inkjet-printed tactile sensors developed on diverse substrates (paper, polymer, glass and textile are presented in this comprehensive review. Recent trends in inkjet-printed wearable/flexible and foldable tactile sensors are evaluated, paving the way for future research.

  5. Review of Recent Inkjet-Printed Capacitive Tactile Sensors.

    Science.gov (United States)

    Salim, Ahmed; Lim, Sungjoon

    2017-11-10

    Inkjet printing is an advanced printing technology that has been used to develop conducting layers, interconnects and other features on a variety of substrates. It is an additive manufacturing process that offers cost-effective, lightweight designs and simplifies the fabrication process with little effort. There is hardly sufficient research on tactile sensors and inkjet printing. Advancements in materials science and inkjet printing greatly facilitate the realization of sophisticated tactile sensors. Starting from the concept of capacitive sensing, a brief comparison of printing techniques, the essential requirements of inkjet-printing and the attractive features of state-of-the art inkjet-printed tactile sensors developed on diverse substrates (paper, polymer, glass and textile) are presented in this comprehensive review. Recent trends in inkjet-printed wearable/flexible and foldable tactile sensors are evaluated, paving the way for future research.

  6. The role of working memory in tactile selective attention.

    Science.gov (United States)

    Dalton, Polly; Lavie, Nilli; Spence, Charles

    2009-04-01

    Load theory suggests that working memory controls the extent to which irrelevant distractors are processed (e.g., Lavie, Hirst, De Fockert, & Viding, 2004). However, so far this proposal has only been tested in vision. Here, we examine the extent to which tactile selective attention also depends on working memory. In Experiment 1, participants focused their attention on continuous target vibrations while attempting to ignore pulsed distractor vibrations. In Experiment 2, targets were always presented to a particular hand, with distractors being presented to the other hand. In both experiments, a high (vs. low) load in a concurrent working memory task led to greater interference by the tactile distractors. These results establish the role of working memory in the control of tactile selective attention, demonstrating for the first time that the principles of load theory also apply to the tactile modality.

  7. Control Framework for Dexterous Manipulation Using Dynamic Visual Servoing and Tactile Sensors’ Feedback

    Directory of Open Access Journals (Sweden)

    Carlos A. Jara

    2014-01-01

    Full Text Available Tactile sensors play an important role in robotics manipulation to perform dexterous and complex tasks. This paper presents a novel control framework to perform dexterous manipulation with multi-fingered robotic hands using feedback data from tactile and visual sensors. This control framework permits the definition of new visual controllers which allow the path tracking of the object motion taking into account both the dynamics model of the robot hand and the grasping force of the fingertips under a hybrid control scheme. In addition, the proposed general method employs optimal control to obtain the desired behaviour in the joint space of the fingers based on an indicated cost function which determines how the control effort is distributed over the joints of the robotic hand. Finally, authors show experimental verifications on a real robotic manipulation system for some of the controllers derived from the control framework.

  8. Perceptual learning with tactile stimuli in rodents: Shaping the somatosensory system.

    Science.gov (United States)

    Pacchiarini, Nicole; Fox, Kevin; Honey, R C

    2017-06-01

    The animal kingdom contains species with a wide variety of sensory systems that have been selected to function in different environmental niches, but that are also subject to modification by experience during an organism's lifetime. The modification of such systems by experience is often called perceptual learning. In rodents, the classic example of perceptual learning is the observation that simple preexposure to two visual stimuli facilitates a subsequent (reinforced) discrimination between them. However, until recently very little behavioral research had investigated perceptual learning with tactile stimuli in rodents, in marked contrast to the wealth of information about plasticity in the rodent somatosensory system. Here we present a selective review of behavioral analyses of perceptual learning with tactile stimuli, alongside evidence concerning the potential bases of such effects within the somatosensory system.

  9. RETENTION OF HIGH TACTILE ACUITY THROUGHOUT THE LIFESPAN IN BLINDNESS

    OpenAIRE

    Legge, Gordon E.; Madison, Cindee; Vaughn, Brenna N.; Cheong, Allen M.Y.; Miller, Joseph C.

    2008-01-01

    Previous studies of tactile acuity on the fingertip using passive touch have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have re-examined this age dependence with two newly designed tactile-acuity charts requiring active exploration of the test symbols. One chart used dot patterns similar to Braille and the other used embossed Landolt rings. Groups of blind Braille readers and sighted subjects, ranging in age from 12 to 85 years, were test...

  10. To what extent do Gestalt grouping principles influence tactile perception?

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2011-07-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli. Although, to date, only a few studies have explicitly investigated the existence of Gestalt grouping principles in the tactile modality, we argue that many more studies have indirectly provided evidence relevant to this topic. Reviewing this body of research, we argue that similar principles to those reported previously in visual and auditory studies also govern the perceptual grouping of tactile stimuli. In particular, we highlight evidence showing that the principles of proximity, similarity, common fate, good continuation, and closure affect tactile perception in both unimodal and crossmodal settings. We also highlight that the grouping of tactile stimuli is often affected by visual and auditory information that happen to be presented simultaneously. Finally, we discuss the theoretical and applied benefits that might pertain to the further study of Gestalt principles operating in both unisensory and multisensory tactile perception.

  11. Audio-Tactile Integration and the Influence of Musical Training

    Science.gov (United States)

    Kuchenbuch, Anja; Paraskevopoulos, Evangelos; Herholz, Sibylle C.; Pantev, Christo

    2014-01-01

    Perception of our environment is a multisensory experience; information from different sensory systems like the auditory, visual and tactile is constantly integrated. Complex tasks that require high temporal and spatial precision of multisensory integration put strong demands on the underlying networks but it is largely unknown how task experience shapes multisensory processing. Long-term musical training is an excellent model for brain plasticity because it shapes the human brain at functional and structural levels, affecting a network of brain areas. In the present study we used magnetoencephalography (MEG) to investigate how audio-tactile perception is integrated in the human brain and if musicians show enhancement of the corresponding activation compared to non-musicians. Using a paradigm that allowed the investigation of combined and separate auditory and tactile processing, we found a multisensory incongruency response, generated in frontal, cingulate and cerebellar regions, an auditory mismatch response generated mainly in the auditory cortex and a tactile mismatch response generated in frontal and cerebellar regions. The influence of musical training was seen in the audio-tactile as well as in the auditory condition, indicating enhanced higher-order processing in musicians, while the sources of the tactile MMN were not influenced by long-term musical training. Consistent with the predictive coding model, more basic, bottom-up sensory processing was relatively stable and less affected by expertise, whereas areas for top-down models of multisensory expectancies were modulated by training. PMID:24465675

  12. Neural Substrate for Metacognitive Accuracy of Tactile Working Memory.

    Science.gov (United States)

    Gogulski, Juha; Zetter, Rasmus; Nyrhinen, Mikko; Pertovaara, Antti; Carlson, Synnöve

    2017-11-01

    The human prefrontal cortex (PFC) has been shown to be important for metacognition, the capacity to monitor and control one's own cognitive processes. Here we dissected the neural architecture of somatosensory metacognition using navigated single-pulse transcranial magnetic stimulation (TMS) to modulate tactile working memory (WM) processing. We asked subjects to perform tactile WM tasks and to give a confidence rating for their performance after each trial. We circumvented the challenge of interindividual variability in functional brain anatomy by applying TMS to two PFC areas that, according to tractography, were neurally connected with the primary somatosensory cortex (S1): one area in the superior frontal gyrus (SFG), another in the middle frontal gyrus (MFG). These two PFC locations and a control cortical area were stimulated during both spatial and temporal tactile WM tasks. We found that tractography-guided TMS of the SFG area selectively enhanced metacognitive accuracy of tactile temporal, but not spatial WM. Stimulation of the MFG area that was also neurally connected with the S1 had no such effect on metacognitive accuracy of either the temporal or spatial tactile WM. Our findings provide causal evidence that the PFC contains distinct neuroanatomical substrates for introspective accuracy of tactile WM. © The Author 2017. Published by Oxford University Press.

  13. Rapid temporal recalibration to visuo-tactile stimuli.

    Science.gov (United States)

    Lange, Joachim; Kapala, Katharina; Krause, Holger; Baumgarten, Thomas J; Schnitzler, Alfons

    2018-02-01

    For a comprehensive understanding of the environment, the brain must constantly decide whether the incoming information originates from the same source and needs to be integrated into a coherent percept. This integration process is believed to be mediated by temporal integration windows. If presented with temporally asynchronous stimuli for a few minutes, the brain adapts to this new temporal relation by recalibrating the temporal integration windows. Such recalibration can occur even more rapidly after exposure to just a single trial of asynchronous stimulation. While rapid recalibration has been demonstrated for audio-visual stimuli, evidence for rapid recalibration of visuo-tactile stimuli is lacking. Here, we investigated rapid recalibration in the visuo-tactile domain. Subjects received visual and tactile stimuli with different stimulus onset asynchronies (SOA) and were asked to report whether the visuo-tactile stimuli were presented simultaneously. Our results demonstrate visuo-tactile rapid recalibration by revealing that subjects' simultaneity reports were modulated by the temporal order of stimulation in the preceding trial. This rapid recalibration effect, however, was only significant if the SOA in the preceding trial was smaller than 100 ms, while rapid recalibration could not be demonstrated for SOAs larger than 100 ms. Since rapid recalibration in the audio-visual domain has been demonstrated for SOAs larger than 100 ms, we propose that visuo-tactile recalibration works at shorter SOAs, and thus faster time scales than audio-visual rapid recalibration.

  14. Audio-tactile integration and the influence of musical training.

    Directory of Open Access Journals (Sweden)

    Anja Kuchenbuch

    Full Text Available Perception of our environment is a multisensory experience; information from different sensory systems like the auditory, visual and tactile is constantly integrated. Complex tasks that require high temporal and spatial precision of multisensory integration put strong demands on the underlying networks but it is largely unknown how task experience shapes multisensory processing. Long-term musical training is an excellent model for brain plasticity because it shapes the human brain at functional and structural levels, affecting a network of brain areas. In the present study we used magnetoencephalography (MEG to investigate how audio-tactile perception is integrated in the human brain and if musicians show enhancement of the corresponding activation compared to non-musicians. Using a paradigm that allowed the investigation of combined and separate auditory and tactile processing, we found a multisensory incongruency response, generated in frontal, cingulate and cerebellar regions, an auditory mismatch response generated mainly in the auditory cortex and a tactile mismatch response generated in frontal and cerebellar regions. The influence of musical training was seen in the audio-tactile as well as in the auditory condition, indicating enhanced higher-order processing in musicians, while the sources of the tactile MMN were not influenced by long-term musical training. Consistent with the predictive coding model, more basic, bottom-up sensory processing was relatively stable and less affected by expertise, whereas areas for top-down models of multisensory expectancies were modulated by training.

  15. Enhancing Perception with Tactile Object Recognition in Adaptive Grippers for Human-Robot Interaction.

    Science.gov (United States)

    Gandarias, Juan M; Gómez-de-Gabriel, Jesús M; García-Cerezo, Alfonso J

    2018-02-26

    The use of tactile perception can help first response robotic teams in disaster scenarios, where visibility conditions are often reduced due to the presence of dust, mud, or smoke, distinguishing human limbs from other objects with similar shapes. Here, the integration of the tactile sensor in adaptive grippers is evaluated, measuring the performance of an object recognition task based on deep convolutional neural networks (DCNNs) using a flexible sensor mounted in adaptive grippers. A total of 15 classes with 50 tactile images each were trained, including human body parts and common environment objects, in semi-rigid and flexible adaptive grippers based on the fin ray effect. The classifier was compared against the rigid configuration and a support vector machine classifier (SVM). Finally, a two-level output network has been proposed to provide both object-type recognition and human/non-human classification. Sensors in adaptive grippers have a higher number of non-null tactels (up to 37% more), with a lower mean of pressure values (up to 72% less) than when using a rigid sensor, with a softer grip, which is needed in physical human-robot interaction (pHRI). A semi-rigid implementation with 95.13% object recognition rate was chosen, even though the human/non-human classification had better results (98.78%) with a rigid sensor.

  16. Design and Evaluation of a Thermal Tactile Display for Colour Rendering

    Directory of Open Access Journals (Sweden)

    Zhen Jia

    2015-11-01

    Full Text Available This paper proposes a novel method of manipulating both thermal change rate and thermal intensity to convey colour information by using a thermal tactile display. The colour-space transformation from {red, green, blue} to {hue, saturation, intensity} is introduced, and the mapping between colour and temperature is established based on warm and cold colours. Considering the lower resolution of the tactile channel, six limited stimulation levels are generated to represent colours. Based on the semi-infinite body model, the thermal response within the skin for each stimulation form is investigated. The Peltier element of the display is designed to convey different thermal stimuli to the human finger. Two experiments are performed to evaluate the performance of the display: colour identification and discrimination. Experimental results indicate that there is a response bias among the perceived colours for the traditional method of only employing thermal intensity, but there is no response bias for the proposed method; subjects’ mean recognition accuracy with the proposed method is significantly higher than that gained using the traditional method. Furthermore, colour information of the captured images can be reliably discriminated by using this devised thermal tactile display.

  17. Enhancing Perception with Tactile Object Recognition in Adaptive Grippers for Human–Robot Interaction

    Directory of Open Access Journals (Sweden)

    Juan M. Gandarias

    2018-02-01

    Full Text Available The use of tactile perception can help first response robotic teams in disaster scenarios, where visibility conditions are often reduced due to the presence of dust, mud, or smoke, distinguishing human limbs from other objects with similar shapes. Here, the integration of the tactile sensor in adaptive grippers is evaluated, measuring the performance of an object recognition task based on deep convolutional neural networks (DCNNs using a flexible sensor mounted in adaptive grippers. A total of 15 classes with 50 tactile images each were trained, including human body parts and common environment objects, in semi-rigid and flexible adaptive grippers based on the fin ray effect. The classifier was compared against the rigid configuration and a support vector machine classifier (SVM. Finally, a two-level output network has been proposed to provide both object-type recognition and human/non-human classification. Sensors in adaptive grippers have a higher number of non-null tactels (up to 37% more, with a lower mean of pressure values (up to 72% less than when using a rigid sensor, with a softer grip, which is needed in physical human–robot interaction (pHRI. A semi-rigid implementation with 95.13% object recognition rate was chosen, even though the human/non-human classification had better results (98.78% with a rigid sensor.

  18. Observations on human tactile directional sensibility.

    Science.gov (United States)

    Olausson, H; Norrsell, U

    1993-01-01

    1. The ability to tell the direction of a motion across the skin deserve attention for being an easily observed function which provides a sensitive test for disturbances of the peripheral and central nervous systems. The mode of operation, on the other hand, of this tactile directional sensibility is still uncertain. 2. The dependence of directional sensibility on the contact load and distance of movement of a blunt metal tip, has now been determined for the skin of the forearm of normal subjects with the two-alternative forced-choice method. The testing was done under two conditions: elbow bent or straight. Straightening of the arm always reduced the accuracy of the directional sensibility. It also caused measurable changes of cutaneous mechanical properties, which presumably decreased the reliability of afferent information about lateral distension. 3. The average accuracy of the directional sensibility was found to be correlated linearly to the logarithm of the contact load, and straightening of the arm decreased the accuracy for each load by corresponding amounts. Similar relationships were found between the accuracy and the distance of movement. 4. Straightening of the arm did not cause any significant average reduction of the contact threshold for point stimulation of the same receptive field. A consistently lowered contact sensitivity, however, was observed for some of the subjects, which may have contributed to the reduction of the directional sensibility in these cases. 5. Correct directional estimations of the movement of the metal tip were obtained for a distance which was a fifth of the shortest distance for a corresponding estimation of the movement of a frictionless stimulus. The findings thus indicated that the friction between a moving object and the underlying skin, which can be mediated via stretch-sensitive cutaneous receptors, is critical for the determination of its direction of motion. 6. The present observations and previous observations by

  19. Flexible Piezoelectric Tactile Sensor Array for Dynamic Three-Axis Force Measurement.

    Science.gov (United States)

    Yu, Ping; Liu, Weiting; Gu, Chunxin; Cheng, Xiaoying; Fu, Xin

    2016-06-03

    A new flexible piezoelectric tactile sensor array based on polyvinylidene fluoride (PVDF) film is proposed for measuring three-axis dynamic contact force distribution. The array consists of six tactile units arranged as a 3 × 2 matrix with spacing 8 mm between neighbor units. In each unit, a PVDF film is sandwiched between four square-shaped upper electrodes and one square-shaped lower electrode, forming four piezoelectric capacitors. A truncated pyramid bump is located above the four piezoelectric capacitors to improve force transmission. A three-axis contact force transmitted from the top of the bump will lead to the four piezoelectric capacitors underneath undergoing different charge changes, from which the normal and shear components of the force can be calculated. A series of dynamic tests have been carried out by exerting sinusoidal forces with amplitudes ranging from 0 to 0.5 N in the x-axis, 0 to 0.5 N in the y-axis, and 0 to 1.5 N in the z-axis, separately. The tactile units show good sensitivities with 14.93, 14.92, and 6.62 pC/N in the x-, y-, and z-axes, respectively. They can work with good linearity, relatively low coupling effect, high repeatability, and acceptable frequency response in the range of 5-400 Hz to both normal and shear load. In addition, dynamic three-axis force measurement has been conducted for all of the tactile units. The average errors between the applied and calculated forces are 10.68% ± 6.84%. Furthermore, the sensor array can be easily integrated onto a curved surface, such as robotic and prosthetic hands, due to its excellent flexibility.

  20. Flexible Piezoelectric Tactile Sensor Array for Dynamic Three-Axis Force Measurement

    Directory of Open Access Journals (Sweden)

    Ping Yu

    2016-06-01

    Full Text Available A new flexible piezoelectric tactile sensor array based on polyvinylidene fluoride (PVDF film is proposed for measuring three-axis dynamic contact force distribution. The array consists of six tactile units arranged as a 3 × 2 matrix with spacing 8 mm between neighbor units. In each unit, a PVDF film is sandwiched between four square-shaped upper electrodes and one square-shaped lower electrode, forming four piezoelectric capacitors. A truncated pyramid bump is located above the four piezoelectric capacitors to improve force transmission. A three-axis contact force transmitted from the top of the bump will lead to the four piezoelectric capacitors underneath undergoing different charge changes, from which the normal and shear components of the force can be calculated. A series of dynamic tests have been carried out by exerting sinusoidal forces with amplitudes ranging from 0 to 0.5 N in the x-axis, 0 to 0.5 N in the y-axis, and 0 to 1.5 N in the z-axis, separately. The tactile units show good sensitivities with 14.93, 14.92, and 6.62 pC/N in the x-, y-, and z-axes, respectively. They can work with good linearity, relatively low coupling effect, high repeatability, and acceptable frequency response in the range of 5–400 Hz to both normal and shear load. In addition, dynamic three-axis force measurement has been conducted for all of the tactile units. The average errors between the applied and calculated forces are 10.68% ± 6.84%. Furthermore, the sensor array can be easily integrated onto a curved surface, such as robotic and prosthetic hands, due to its excellent flexibility.

  1. Tactile Models and Games as Learning Tools for Topics of Molecular and Cell Biology

    Directory of Open Access Journals (Sweden)

    Nelma Regina Segnini Bossolan

    2017-07-01

    Full Text Available The cell structure and the dynamics of its functioning are basic topics for the understanding of phenomena on a larger scale in living organisms and for which research in science teaching has suggested several strategies based on the use of images, games, computational simulations and tactile models, among other types of external representations. Our science education research group, over the last 17 years, has developed and evaluated educational materials for teaching these topics, aimed at all levels of school. Among these materials, we highlight the tactile models for the assembly of nucleic acid, amino acids and proteins molecules, as well as a board game that deals with the process of protein synthesis. These materials were evaluated with students from the final grades of elementary and high school, in the context of the Natural Sciences Curriculum of the State of São Paulo, as well as students from two higher level courses, one of them Licentiate’s program in Exact Sciences. Activities were planned with a problem-solving approach and carried out in small groups. Tactile models of nucleic acid aided elementary students in understanding the role of these molecules in the transmission of hereditary traits. The game of protein synthesis, which depicts this process in a schematic eukaryotic cell where the participants aim to synthesize a particular protein, promoted the development of skills such as “decision making” and “making anticipations” among high school students, in addition of expanding their knowledge about the biological functions of these molecules. The tactile models of amino acids and proteins used by students of higher education promoted their spatial perception of these molecules, allowing the prediction of intra- and intermolecular interactions. It is important to emphasize the importance of these educational resources in the construction of more functional mental models of cells and of intracellular processes.

  2. Higher Network Activity Induced by Tactile Compared to Electrical Stimulation of Leech Mechanoreceptors

    Directory of Open Access Journals (Sweden)

    Elham Fathiazar

    2018-03-01

    Full Text Available The tiny ensemble of neurons in the leech ganglion can discriminate the locations of touch stimuli on the skin as precisely as a human fingertip. The leech uses this ability to locally bend the body-wall away from the stimulus. It is assumed that a three-layered feedforward network of pressure mechanoreceptors, interneurons, and motor neurons controls this behavior. Most previous studies identified and characterized the local bend network based on electrical stimulation of a single pressure mechanoreceptor, which was sufficient to trigger the local bend response. Recent studies showed, however, that up to six mechanoreceptors of three types innervating the stimulated patch of skin carry information about both touch intensity and location simultaneously. Therefore, we hypothesized that interneurons involved in the local bend network might require the temporally concerted inputs from the population of mechanoreceptors representing tactile stimuli, to decode the tactile information and to provide appropriate synaptic inputs to the motor neurons. We examined the influence of current injection into a single mechanoreceptor on activity of postsynaptic interneurons in the network and compared it to responses of interneurons to skin stimulation with different pressure intensities. We used voltage-sensitive dye imaging to monitor the graded membrane potential changes of all visible cells on the ventral side of the ganglion. Our results showed that stimulation of a single mechanoreceptor activates several local bend interneurons, consistent with previous intracellular studies. Tactile skin stimulation, however, evoked a more pronounced, longer-lasting, stimulus intensity-dependent network dynamics involving more interneurons. We concluded that the underlying local bend network enables a non-linear processing of tactile information provided by population of mechanoreceptors. This task requires a more complex network structure than previously assumed

  3. Cross-sensory facilitation reveals neural interactions between visual and tactile motion in humans

    Directory of Open Access Journals (Sweden)

    Monica eGori

    2011-04-01

    Full Text Available Many recent studies show that the human brain integrates information across the different senses and that stimuli of one sensory modality can enhance the perception of other modalities. Here we study the processes that mediate cross-modal facilitation and summation between visual and tactile motion. We find that while summation produced a generic, non-specific improvement of thresholds, probably reflecting higher-order interaction of decision signals, facilitation reveals a strong, direction-specific interaction, which we believe reflects sensory interactions. We measured visual and tactile velocity discrimination thresholds over a wide range of base velocities and conditions. Thresholds for both visual and tactile stimuli showed the characteristic dipper function, with the minimum thresholds occurring at a given pedestal speed. When visual and tactile coherent stimuli were combined (summation condition the thresholds for these multi-sensory stimuli also showed a dipper function with the minimum thresholds occurring in a similar range to that for unisensory signals. However, the improvement of multisensory thresholds was weak and not directionally specific, well predicted by the maximum likelihood estimation model (agreeing with previous research. A different technique (facilitation did, however, reveal direction-specific enhancement. Adding a non-informative pedestal motion stimulus in one sensory modality (vision or touch selectively lowered thresholds in the other, by the same amount as pedestals in the same modality. Facilitation did not occur for neutral stimuli like sounds (that would also have reduced temporal uncertainty, nor for motion in opposite direction, even in blocked trials where the subjects knew that the motion was in the opposite direction showing that the facilitation was not under subject control. Cross-sensory facilitation is strong evidence for functionally relevant cross-sensory integration at early levels of sensory

  4. Parametric investigation of scalable tactile sensors

    Science.gov (United States)

    Saadatzi, Mohammad Nasser; Yang, Zhong; Baptist, Joshua R.; Sahasrabuddhe, Ritvij R.; Wijayasinghe, Indika B.; Popa, Dan O.

    2017-05-01

    In the near future, robots and humans will share the same environment and perform tasks cooperatively. For intuitive, safe, and reliable physical human-robot interaction (pHRI), sensorized robot skins for tactile measurements of contact are necessary. In a previous study, we presented skins consisting of strain gauge arrays encased in silicone encapsulants. Although these structures could measure normal forces applied directly onto the sensing elements, they also exhibited blind spots and response asymmetry to certain loading patterns. This study presents a parametric investigation of piezoresistive polymeric strain gauge that exhibits a symmetric omniaxial response thanks to its novel star-shaped structure. This strain gauge relies on the use of gold micro-patterned star-shaped structures with a thin layer of PEDOT:PSS which is a flexible polymer with piezoresistive properties. In this paper, the sensor is first modeled and comprehensively analyzed in the finite-element simulation environment COMSOL. Simulations include stress-strain loading for a variety of structure parameters such as gauge lengths, widths, and spacing, as well as multiple load locations relative to the gauge. Subsequently, sensors with optimized configurations obtained through simulations were fabricated using cleanroom photolithographic and spin-coating processes, and then experimentally tested. Results show a trend-wise agreement between experiments and simulations.

  5. Development of patterned carbon nanotubes on a 3D polymer substrate for the flexible tactile sensor application

    International Nuclear Information System (INIS)

    Hu, Chih-Fan; Fang, Weileun; Su, Wang-Shen

    2011-01-01

    This study reports an improved approach to implement a carbon nanotube (CNT)-based flexible tactile sensor, which is integrated with a flexible print circuit (FPC) connector and is capable of detecting normal and shear forces. The merits of the presented tactile sensor by the integration process are as follows: (1) 3D polymer tactile bump structures are naturally formed by the use of an anisotropically etched silicon mold; (2) planar and 3D distributed CNTs are adopted as piezoresistive sensing elements to enable the detection of shear and normal forces; (3) the processes of patterning CNTs and metal routing can be easily batch fabricated on rigid silicon instead of flexible polymer; (4) robust electrical routing is realized using parylene encapsulation to avoid delamination; (5) patterned CNTs, electrical routing and FPC connector are integrated and transferred to a polydimethylsiloxane (PDMS) substrate by a molding process. In application, the CNT-based flexible tactile sensor and its integration with the FPC connector are implemented. Preliminary tests show the feasibility of detecting both normal and shear forces using the presented flexible sensor.

  6. Braille in the Sighted: Teaching Tactile Reading to Sighted Adults.

    Science.gov (United States)

    Bola, Łukasz; Siuda-Krzywicka, Katarzyna; Paplińska, Małgorzata; Sumera, Ewa; Hańczur, Paweł; Szwed, Marcin

    2016-01-01

    Blind people are known to have superior perceptual abilities in their remaining senses. Several studies suggest that these enhancements are dependent on the specific experience of blind individuals, who use those remaining senses more than sighted subjects. In line with this view, sighted subjects, when trained, are able to significantly progress in relatively simple tactile tasks. However, the case of complex tactile tasks is less obvious, as some studies suggest that visual deprivation itself could confer large advantages in learning them. It remains unclear to what extent those complex skills, such as braille reading, can be learnt by sighted subjects. Here we enrolled twenty-nine sighted adults, mostly braille teachers and educators, in a 9-month braille reading course. At the beginning of the course, all subjects were naive in tactile braille reading. After the course, almost all were able to read whole braille words at a mean speed of 6 words-per-minute. Subjects with low tactile acuity did not differ significantly in braille reading speed from the rest of the group, indicating that low tactile acuity is not a limiting factor for learning braille, at least at this early stage of learning. Our study shows that most sighted adults can learn whole-word braille reading, given the right method and a considerable amount of motivation. The adult sensorimotor system can thus adapt, to some level, to very complex tactile tasks without visual deprivation. The pace of learning in our group was comparable to congenitally and early blind children learning braille in primary school, which suggests that the blind's mastery of complex tactile tasks can, to a large extent, be explained by experience-dependent mechanisms.

  7. Tactile Radar: experimenting a computer game with visually disabled.

    Science.gov (United States)

    Kastrup, Virgínia; Cassinelli, Alvaro; Quérette, Paulo; Bergstrom, Niklas; Sampaio, Eliana

    2017-09-18

    Visually disabled people increasingly use computers in everyday life, thanks to novel assistive technologies better tailored to their cognitive functioning. Like sighted people, many are interested in computer games - videogames and audio-games. Tactile-games are beginning to emerge. The Tactile Radar is a device through which a visually disabled person is able to detect distal obstacles. In this study, it is connected to a computer running a tactile-game. The game consists in finding and collecting randomly arranged coins in a virtual room. The study was conducted with nine congenital blind people including both sexes, aged 20-64 years old. Complementary methods of first and third person were used: the debriefing interview and the quasi-experimental design. The results indicate that the Tactile Radar is suitable for the creation of computer games specifically tailored for visually disabled people. Furthermore, the device seems capable of eliciting a powerful immersive experience. Methodologically speaking, this research contributes to the consolidation and development of first and third person complementary methods, particularly useful in disabled people research field, including the evaluation by users of the Tactile Radar effectiveness in a virtual reality context. Implications for rehabilitation Despite the growing interest in virtual games for visually disabled people, they still find barriers to access such games. Through the development of assistive technologies such as the Tactile Radar, applied in virtual games, we can create new opportunities for leisure, socialization and education for visually disabled people. The results of our study indicate that the Tactile Radar is adapted to the creation of video games for visually disabled people, providing a playful interaction with the players.

  8. Object recognition and localization: the role of tactile sensors.

    Science.gov (United States)

    Aggarwal, Achint; Kirchner, Frank

    2014-02-18

    Tactile sensors, because of their intrinsic insensitivity to lighting conditions and water turbidity, provide promising opportunities for augmenting the capabilities of vision sensors in applications involving object recognition and localization. This paper presents two approaches for haptic object recognition and localization for ground and underwater environments. The first approach called Batch Ransac and Iterative Closest Point augmented Particle Filter (BRICPPF) is based on an innovative combination of particle filters, Iterative-Closest-Point algorithm, and a feature-based Random Sampling and Consensus (RANSAC) algorithm for database matching. It can handle a large database of 3D-objects of complex shapes and performs a complete six-degree-of-freedom localization of static objects. The algorithms are validated by experimentation in ground and underwater environments using real hardware. To our knowledge this is the first instance of haptic object recognition and localization in underwater environments. The second approach is biologically inspired, and provides a close integration between exploration and recognition. An edge following exploration strategy is developed that receives feedback from the current state of recognition. A recognition by parts approach is developed which uses the BRICPPF for object sub-part recognition. Object exploration is either directed to explore a part until it is successfully recognized, or is directed towards new parts to endorse the current recognition belief. This approach is validated by simulation experiments.

  9. Object Recognition and Localization: The Role of Tactile Sensors

    Directory of Open Access Journals (Sweden)

    Achint Aggarwal

    2014-02-01

    Full Text Available Tactile sensors, because of their intrinsic insensitivity to lighting conditions and water turbidity, provide promising opportunities for augmenting the capabilities of vision sensors in applications involving object recognition and localization. This paper presents two approaches for haptic object recognition and localization for ground and underwater environments. The first approach called Batch Ransac and Iterative Closest Point augmented Particle Filter (BRICPPF is based on an innovative combination of particle filters, Iterative-Closest-Point algorithm, and a feature-based Random Sampling and Consensus (RANSAC algorithm for database matching. It can handle a large database of 3D-objects of complex shapes and performs a complete six-degree-of-freedom localization of static objects. The algorithms are validated by experimentation in ground and underwater environments using real hardware. To our knowledge this is the first instance of haptic object recognition and localization in underwater environments. The second approach is biologically inspired, and provides a close integration between exploration and recognition. An edge following exploration strategy is developed that receives feedback from the current state of recognition. A recognition by parts approach is developed which uses the BRICPPF for object sub-part recognition. Object exploration is either directed to explore a part until it is successfully recognized, or is directed towards new parts to endorse the current recognition belief. This approach is validated by simulation experiments.

  10. Stimulus-dependent effects on tactile spatial acuity

    Directory of Open Access Journals (Sweden)

    Tommerdahl M

    2005-10-01

    Full Text Available Abstract Background Previous studies have shown that spatio-tactile acuity is influenced by the clarity of the cortical response in primary somatosensory cortex (SI. Stimulus characteristics such as frequency, amplitude, and location of tactile stimuli presented to the skin have been shown to have a significant effect on the response in SI. The present study observes the effect of changing stimulus parameters of 25 Hz sinusoidal vertical skin displacement stimulation ("flutter" on a human subject's ability to discriminate between two adjacent or near-adjacent skin sites. Based on results obtained from recent neurophysiological studies of the SI response to different conditions of vibrotactile stimulation, we predicted that the addition of 200 Hz vibration to the same site that a two-point flutter stimulus was delivered on the skin would improve a subject's spatio-tactile acuity over that measured with flutter alone. Additionally, similar neurophysiological studies predict that the presence of either a 25 Hz flutter or 200 Hz vibration stimulus on the unattended hand (on the opposite side of the body from the site of two-point limen testing – the condition of bilateral stimulation – which has been shown to evoke less SI cortical activity than the contralateral-only stimulus condition would decrease a subject's ability to discriminate between two points on the skin. Results A Bekesy tracking method was employed to track a subject's ability to discriminate between two-point stimuli delivered to the skin. The distance between the two points of stimulation was varied on a trial-by-trial basis, and several different stimulus conditions were examined: (1 The "control" condition, in which 25 Hz flutter stimuli were delivered simultaneously to the two points on the skin of the attended hand, (2 the "complex" condition, in which a combination of 25 Hz flutter and 200 Hz vibration stimuli were delivered to the two points on the attended hand, and (3 a

  11. Tactile mouse generating velvet hand illusion on human palm

    Directory of Open Access Journals (Sweden)

    Nadar Rajaei

    2016-09-01

    Full Text Available To enhance virtual reality (VR generated by tactile displays, we have focused on a novel tactile illusion, called the Velvet Hand Illusion (VHI. In VHI, moving two parallel wires back and forth between the two hands leads humans to perceive a velvet-like surface between their hands. In earlier studies, we revealed that the intensity of VHI could be controlled by a ratio (r/D, where r and D are the wire stroke and wire distance, respectively. According to these findings, we investigate in this study whether a common tactile display is able to produce VHI, and whether the ratio can also control VHI intensity. We prepare a dot-matrix display as a tactile display in which moving one line of the display’s pins is considered as a wire pattern. We investigate the VHI intensity with regard to changing the stroke r and the line distance D using paired comparison. Experimental results show that the VHI intensity is increased or decreased by changing r and D. We conclude that VHI can be created by the tactile display, and the intensity of VHI is controlled by changing the ratio of r/D.

  12. Nitrogen narcosis and tactile shape memory in low visibility.

    Science.gov (United States)

    van Wijk, Charles H; Meintjes, W A J

    2014-01-01

    Commercial diving often occurs in low visibility, where divers are reliant on their tactile senses. This study examined the effect of nitrogen narcosis on tactile memory for shapes as well as the influence of psychological and biographical factors on this relationship. This crossover study tested 139 commercial divers in a dry hyperbaric chamber at 101.325 and 607.95 kPa (1 and 6 atmospheres absolute/atm abs). Divers memorized shapes while blindfolded, using their tactile senses only. Delayed recall was measured at the surface after each dive. Psychological and biographical data were also collected. A significant effect of hyperbaric pressure on tactile memory was demonstrated, and a further effect of sequence of testing found. Thus, divers' delayed shape recall deteriorated by 8% after learning material at depth, compared to learning on the surface. There were also significant but small effects of psychological and biographical markers on tactile memory performance, with lower trait anxiety associated with better recall, and lower education associated with poorer recall. The findings emphasize the importance of utilizing other forms of recording of events or objects at depth, particularly in conditions of low visibility during deeper diving, to aid memory encoding and subsequent recall at the surface.

  13. Tactile sensory system: encoding from the periphery to the cortex.

    Science.gov (United States)

    Jones, Lynette A; Smith, Allan M

    2014-01-01

    Specialized mechanoreceptors in the skin respond to mechanical deformation and provide the primary input to the tactile sensory system. Although the morphology of these receptors has been documented, there is still considerable uncertainty as to the relation between cutaneous receptor morphology and the associated physiological responses to stimulation. Labelled-line models of somatosensory processes in which specific mechanoreceptors are associated with particular sensory qualities fail to account for the evidence showing that all types of tactile afferent units respond to a varying extent to most types of natural stimuli. Neurophysiological and psychophysical experiments have provided the framework for determining the relation between peripheral afferent or cortical activity and tactile perception. Neural codes derived from these afferent signals are evaluated in terms of their capacity to predict human perceptual performance. One particular challenge in developing models of the tactile sensory system is the dual use of sensory signals from the skin. In addition to their perceptual function they serve as inputs to the sensorimotor control system involved in manipulation. Perceptions generated through active touch differ from those resulting from passive stimulation of the skin because they are the product of self-generated exploratory processes. Recent research in this area has highlighted the importance of shear forces in these exploratory movements and has shown that fingertip skin is particularly sensitive to shear generated during both object manipulation and tactile exploration. © 2014 Wiley Periodicals, Inc.

  14. Visual detail about the body modulates tactile localisation biases.

    Science.gov (United States)

    Margolis, Aaron N; Longo, Matthew R

    2015-02-01

    The localisation of tactile stimuli requires the integration of visual and somatosensory inputs within an internal representation of the body surface and is prone to consistent bias. Joints may play a role in segmenting such internal body representations, and may therefore influence tactile localisation biases, although the nature of this influence remains unclear. Here, we investigate the relationship between conceptual knowledge of joint locations and tactile localisation biases on the hand. In one task, participants localised tactile stimuli applied to the dorsum of their hand. A distal localisation bias was observed in all participants, consistent with previous results. We also manipulated the availability of visual information during this task, to determine whether the absence of this information could account for the distal bias observed here and by Mancini et al. (Neuropsychologia 49:1194-1201, 2011). The observed distal bias increased in magnitude when visual information was restricted, without a corresponding decrease in precision. In a separate task, the same participants indicated, from memory, knuckle locations on a silhouette image of their hand. Analogous distal biases were also seen in the knuckle localisation task. The accuracy of conceptual joint knowledge was not correlated with tactile localisation bias magnitude, although a similarity in observed bias direction suggests that both tasks may rely on a common, higher-order body representation. These results also suggest that distortions of conceptual body representation may be more common in healthy individuals than previously thought.

  15. Synthetic and Bio-Artificial Tactile Sensing: A Review

    Directory of Open Access Journals (Sweden)

    Maria Chiara Carrozza

    2013-01-01

    Full Text Available This paper reviews the state of the art of artificial tactile sensing, with a particular focus on bio-hybrid and fully-biological approaches. To this aim, the study of physiology of the human sense of touch and of the coding mechanisms of tactile information is a significant starting point, which is briefly explored in this review. Then, the progress towards the development of an artificial sense of touch are investigated. Artificial tactile sensing is analysed with respect to the possible approaches to fabricate the outer interface layer: synthetic skin versus bio-artificial skin. With particular respect to the synthetic skin approach, a brief overview is provided on various technologies and transduction principles that can be integrated beneath the skin layer. Then, the main focus moves to approaches characterized by the use of bio-artificial skin as an outer layer of the artificial sensory system. Within this design solution for the skin, bio-hybrid and fully-biological tactile sensing systems are thoroughly presented: while significant results have been reported for the development of tissue engineered skins, the development of mechanotransduction units and their integration is a recent trend that is still lagging behind, therefore requiring research efforts and investments. In the last part of the paper, application domains and perspectives of the reviewed tactile sensing technologies are discussed.

  16. EAP application to artificial tactile feel display of virtual reality

    Science.gov (United States)

    Konyo, Masashi; Tadokoro, Satoshi; Takamori, Toshi; Oguro, Keisuke

    2001-07-01

    A tactile feel display device for virtual reality was developed using Nafion-Platinum composite type EAP actuator (known as IPMC or ICPF). Conventional tactile displays can hardly express tactile human feeling of the fine touch of the surface of a cloth, because their mechanisms cannot excite minute distributed stimuli on human skin. We propose a new ciliary device using ICPF actuators. The ICPF has sufficient softness, utilizing the passive material property, that complex control is not required. The low drive voltage is safe enough for the touch of fingers. Its simple operation mechanism allows miniaturization for practical equipments. The developed device was designed with a number of cilia consisting of ICPF actuators, where a cilium is 2 mm wide and 5 mm long. An ICPF membrane is cut into pectination, and only the cilium part is plated and has a function of an actuator. An inclined configuration of the cilia produces variety of stimuli to human skin controlling frequencies. We tried to display both pressure and vibration at the same time using modulated low and high frequencies. The result clearly shows that over 80% of the subjects sensed some special tactile feeling. A comparison with real material samples shows that this display can present a subtle distinction of tactile feeling of cloth, especially like a towel and denim.

  17. A Tactile Sensor Network System Using a Multiple Sensor Platform with a Dedicated CMOS-LSI for Robot Applications †

    Science.gov (United States)

    Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Bartley, Travis; Muroyama, Masanori

    2017-01-01

    Robot tactile sensation can enhance human–robot communication in terms of safety, reliability and accuracy. The final goal of our project is to widely cover a robot body with a large number of tactile sensors, which has significant advantages such as accurate object recognition, high sensitivity and high redundancy. In this study, we developed a multi-sensor system with dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) circuit chips (referred to as “sensor platform LSI”) as a framework of a serial bus-based tactile sensor network system. The sensor platform LSI supports three types of sensors: an on-chip temperature sensor, off-chip capacitive and resistive tactile sensors, and communicates with a relay node via a bus line. The multi-sensor system was first constructed on a printed circuit board to evaluate basic functions of the sensor platform LSI, such as capacitance-to-digital and resistance-to-digital conversion. Then, two kinds of external sensors, nine sensors in total, were connected to two sensor platform LSIs, and temperature, capacitive and resistive sensing data were acquired simultaneously. Moreover, we fabricated flexible printed circuit cables to demonstrate the multi-sensor system with 15 sensor platform LSIs operating simultaneously, which showed a more realistic implementation in robots. In conclusion, the multi-sensor system with up to 15 sensor platform LSIs on a bus line supporting temperature, capacitive and resistive sensing was successfully demonstrated. PMID:29061954

  18. Advances in Bio-Tactile Sensors for Minimally Invasive Surgery Using the Fibre Bragg Grating Force Sensor Technique: A Survey

    Directory of Open Access Journals (Sweden)

    Abdulfatah A.G. Abushagur

    2014-04-01

    Full Text Available The large interest in utilising fibre Bragg grating (FBG strain sensors for minimally invasive surgery (MIS applications to replace conventional electrical tactile sensors has grown in the past few years. FBG strain sensors offer the advantages of optical fibre sensors, such as high sensitivity, immunity to electromagnetic noise, electrical passivity and chemical inertness, but are not limited by phase discontinuity or intensity fluctuations. FBG sensors feature a wavelength-encoding sensing signal that enables distributed sensing that utilises fewer connections. In addition, their flexibility and lightness allow easy insertion into needles and catheters, thus enabling localised measurements inside tissues and blood. Two types of FBG tactile sensors have been emphasised in the literature: single-point and array FBG tactile sensors. This paper describes the current design, development and research of the optical fibre tactile techniques that are based on FBGs to enhance the performance of MIS procedures in general. Providing MIS or microsurgery surgeons with accurate and precise measurements and control of the contact forces during tissues manipulation will benefit both surgeons and patients.

  19. Advances in bio-tactile sensors for minimally invasive surgery using the fibre Bragg grating force sensor technique: a survey.

    Science.gov (United States)

    Abushagur, Abdulfatah A G; Arsad, Norhana; Reaz, Mamun Ibne; Bakar, A Ashrif A

    2014-04-09

    The large interest in utilising fibre Bragg grating (FBG) strain sensors for minimally invasive surgery (MIS) applications to replace conventional electrical tactile sensors has grown in the past few years. FBG strain sensors offer the advantages of optical fibre sensors, such as high sensitivity, immunity to electromagnetic noise, electrical passivity and chemical inertness, but are not limited by phase discontinuity or intensity fluctuations. FBG sensors feature a wavelength-encoding sensing signal that enables distributed sensing that utilises fewer connections. In addition, their flexibility and lightness allow easy insertion into needles and catheters, thus enabling localised measurements inside tissues and blood. Two types of FBG tactile sensors have been emphasised in the literature: single-point and array FBG tactile sensors. This paper describes the current design, development and research of the optical fibre tactile techniques that are based on FBGs to enhance the performance of MIS procedures in general. Providing MIS or microsurgery surgeons with accurate and precise measurements and control of the contact forces during tissues manipulation will benefit both surgeons and patients.

  20. A Tactile Sensor Network System Using a Multiple Sensor Platform with a Dedicated CMOS-LSI for Robot Applications.

    Science.gov (United States)

    Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Bartley, Travis; Nonomura, Yutaka; Muroyama, Masanori

    2017-08-28

    Robot tactile sensation can enhance human-robot communication in terms of safety, reliability and accuracy. The final goal of our project is to widely cover a robot body with a large number of tactile sensors, which has significant advantages such as accurate object recognition, high sensitivity and high redundancy. In this study, we developed a multi-sensor system with dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) circuit chips (referred to as "sensor platform LSI") as a framework of a serial bus-based tactile sensor network system. The sensor platform LSI supports three types of sensors: an on-chip temperature sensor, off-chip capacitive and resistive tactile sensors, and communicates with a relay node via a bus line. The multi-sensor system was first constructed on a printed circuit board to evaluate basic functions of the sensor platform LSI, such as capacitance-to-digital and resistance-to-digital conversion. Then, two kinds of external sensors, nine sensors in total, were connected to two sensor platform LSIs, and temperature, capacitive and resistive sensing data were acquired simultaneously. Moreover, we fabricated flexible printed circuit cables to demonstrate the multi-sensor system with 15 sensor platform LSIs operating simultaneously, which showed a more realistic implementation in robots. In conclusion, the multi-sensor system with up to 15 sensor platform LSIs on a bus line supporting temperature, capacitive and resistive sensing was successfully demonstrated.

  1. Direct tactile manipulation of the flight plan in a modern aircraft cockpit

    DEFF Research Database (Denmark)

    Alapetite, Alexandre; Fogh, Rune; Zammit-Mangion, David

    2012-01-01

    An original experimental approach has been chosen, with an incremental progression from a traditional physical cockpit, to a tactile flight simulator reproducing traditional controls, to a prototype navigation display with direct tactile functionality, first located in the traditional low positio...

  2. Flexible Electronics Sensors for Tactile Multi-Touching

    Directory of Open Access Journals (Sweden)

    Shao-Hsing Yeh

    2009-02-01

    Full Text Available Flexible electronics sensors for tactile applications in multi-touch sensing and large scale manufacturing were designed and fabricated. The sensors are based on polyimide substrates, with thixotropy materials used to print organic resistances and a bump on the top polyimide layer. The gap between the bottom electrode layer and the resistance layer provides a buffer distance to reduce erroneous contact during large bending. Experimental results show that the top membrane with a bump protrusion and a resistance layer had a large deflection and a quick sensitive response. The bump and resistance layer provided a concentrated von Mises stress force and inertial force on the top membrane center. When the top membrane had no bump, it had a transient response delay time and took longer to reach steady-state. For printing thick structures of flexible electronics sensors, diffusion effects and dimensional shrinkages can be improved by using a paste material with a high viscosity. Linear algorithm matrixes with Gaussian elimination and control system scanning were used for multi-touch detection. Flexible electronics sensors were printed with a resistance thickness of about 32 µm and a bump thickness of about 0.2 mm. Feasibility studies show that printing technology is appropriate for large scale manufacturing, producing sensors at a low cost.

  3. Tactile Sensing for Dexterous Robotic Hands

    Science.gov (United States)

    Martin, Toby B.

    2000-01-01

    Robotic systems will be used as precursors to human exploration to explore the solar system and expand our knowledge of planetary surfaces. Robotic systems will also be used to build habitats and infrastructure required for human presence in space and on other planetary surfaces . Such robots will require a high level of intelligence and automation. The ability to flexibly manipulate their physical environment is one characteristic that makes humans so effective at these building and exploring tasks . The development of a generic autonomous grasp ing capability will greatly enhance the efficiency and ability of robotics to build, maintain and explore. To tele-operate a robot over vast distances of space, with long communication delays, has proven to be troublesome. Having an autonomous grasping capability that can react in real-time to disturbances or adapt to generic objects, without operator intervention, will reduce the probability of mishandled tools and samples and reduce the number of re-grasp attempts due to dropping. One aspect that separates humans from machines is a rich sensor set. We have the ability to feel objects and respond to forces and textures. The development of touch or tactile sensors for use on a robot that emulates human skin and nerves is the basis for this discussion. We will discuss the use of new piezo-electric and resistive materials that have emerged on the market with the intention of developing a touch sensitive sensor. With viable tacti le sensors we will be one step closer to developing an autonomous grasping capability.

  4. Tactile and proprioceptive temporal discrimination are impaired in functional tremor.

    Directory of Open Access Journals (Sweden)

    Michele Tinazzi

    Full Text Available In order to obtain further information on the pathophysiology of functional tremor, we assessed tactile discrimination threshold and proprioceptive temporal discrimination motor threshold values in 11 patients with functional tremor, 11 age- and sex-matched patients with essential tremor and 13 healthy controls.Tactile discrimination threshold in both the right and left side was significantly higher in patients with functional tremor than in the other groups. Proprioceptive temporal discrimination threshold for both right and left side was significantly higher in patients with functional and essential tremor than in healthy controls. No significant correlation between discrimination thresholds and duration or severity of tremor was found.Temporal processing of tactile and proprioceptive stimuli is impaired in patients with functional tremor. The mechanisms underlying this impaired somatosensory processing and possible ways to apply these findings clinically merit further research.

  5. Tactile display for virtual 3D shape rendering

    CERN Document Server

    Mansutti, Alessandro; Bordegoni, Monica; Cugini, Umberto

    2017-01-01

    This book describes a novel system for the simultaneous visual and tactile rendering of product shapes which allows designers to simultaneously touch and see new product shapes during the conceptual phase of product development. This system offers important advantages, including potential cost and time savings, compared with the standard product design process in which digital 3D models and physical prototypes are often repeatedly modified until an optimal design is achieved. The system consists of a tactile display that is able to represent, within a real environment, the shape of a product. Designers can explore the rendered surface by touching curves lying on the product shape, selecting those curves that can be considered style features and evaluating their aesthetic quality. In order to physically represent these selected curves, a flexible surface is modeled by means of servo-actuated modules controlling a physical deforming strip. The tactile display is designed so as to be portable, low cost, modular,...

  6. Tactile Acuity Charts: A Reliable Measure of Spatial Acuity

    Science.gov (United States)

    Bruns, Patrick; Camargo, Carlos J.; Campanella, Humberto; Esteve, Jaume; Dinse, Hubert R.; Röder, Brigitte

    2014-01-01

    For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds. PMID:24504346

  7. Tactile acuity charts: a reliable measure of spatial acuity.

    Directory of Open Access Journals (Sweden)

    Patrick Bruns

    Full Text Available For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds.

  8. Tactile acuity charts: a reliable measure of spatial acuity.

    Science.gov (United States)

    Bruns, Patrick; Camargo, Carlos J; Campanella, Humberto; Esteve, Jaume; Dinse, Hubert R; Röder, Brigitte

    2014-01-01

    For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds.

  9. Establishing Auditory-Tactile-Visual Equivalence Classes in Children with Autism and Developmental Delays

    Science.gov (United States)

    Mullen, Stuart; Dixon, Mark R.; Belisle, Jordan; Stanley, Caleb

    2017-01-01

    The current study sought to evaluate the efficacy of a stimulus equivalence training procedure in establishing auditory-tactile-visual stimulus classes with 2 children with autism and developmental delays. Participants were exposed to vocal-tactile (A-B) and tactile-picture (B-C) conditional discrimination training and were tested for the…

  10. An insect-inspired bionic sensor for tactile localization and material classification with state-dependent modulation.

    Science.gov (United States)

    Patanè, Luca; Hellbach, Sven; Krause, André F; Arena, Paolo; Dürr, Volker

    2012-01-01

    INSECTS CARRY A PAIR OF ANTENNAE ON THEIR HEAD: multimodal sensory organs that serve a wide range of sensory-guided behaviors. During locomotion, antennae are involved in near-range orientation, for example in detecting, localizing, probing, and negotiating obstacles. Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe and basal angular encoders allow tactile localization in a polar coordinate system. Finally, the damping behavior of the registered signal is exploited to determine the most likely material. The tactile sensor is tested in four approaches with increasing neural plausibility: first, we show that peak extraction from the Fourier spectrum is sufficient for tactile localization with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network (ANN) which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorization. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the input signals.

  11. An insect-inspired bionic sensor for tactile localisation and material classification with state-dependent modulation

    Directory of Open Access Journals (Sweden)

    Luca ePatanè

    2012-08-01

    Full Text Available Insects carry a pair of antennae on their head: multimodal sensory organs that serve a wide range of sensory-guided behaviours. During locomotion, antennae are involved in near-range orientation, for example in detecting, localising, probing and negotiating obstacles.Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe, and basal angular encoders allow tactile localisation in a polar coordinate system. Finally, the damping behaviour of the registered signal is exploited to determine the most likely material.The tactile sensor is tested in four approaches with increasing neural plausibility: First, we show that peak extraction from the Fourier spectrum is sufficient for tactile localisation with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorisation. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the

  12. Use of Pain Neuroscience Education, Tactile Discrimination, and Graded Motor Imagery in an Individual With Frozen Shoulder.

    Science.gov (United States)

    Sawyer, Eric E; McDevitt, Amy W; Louw, Adriaan; Puentedura, Emilio J; Mintken, Paul E

    2018-03-01

    Study Design Case report. Background Aggressive physical therapy in the freezing stage of frozen shoulder may prolong the course of recovery. Central sensitization may play a role in the early stages of frozen shoulder. Pain neuroscience education, tactile discrimination, and graded motor imagery have been used in a number of conditions with central sensitization. The purpose of this case report was to describe the examination and treatment of a patient in the freezing stage of frozen shoulder using pain neuroscience education, tactile discrimination, and graded motor imagery. Case Description A 54-year-old woman with a diagnosis of frozen shoulder was referred by an orthopaedic surgeon following lack of progress after 4 weeks of intensive daily physical therapy. Pain at rest was 7/10, and her Shoulder Pain and Disability Index score was 64%. She had painful and limited active range of motion and elevated fear-avoidance beliefs. Tactile discrimination and limb laterality were impaired, with signs of central sensitization. A "top-down" approach using pain neuroscience education, tactile discrimination, and graded motor imagery was used for the first 6 weeks, followed by a "bottom-up" impairment-based approach. Outcomes The patient was seen for 20 sessions over 12 weeks. At discharge, her Shoulder Pain and Disability Index score was 22%, resting pain was 0/10, and fear-avoidance beliefs improved. Improvements in active range of motion, laterality, and tactile discrimination were also noted. Discussion Intensive physical therapy in the freezing stage of frozen shoulder may be detrimental to long-term outcomes. This case report suggests that a top-down approach may allow a quicker transition through the freezing stage of frozen shoulder. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2018;48(3):174-184. Epub 19 Dec 2017. doi:10.2519/jospt.2018.7716.

  13. Accuracy of Tactile Assessment of Fever in Children by Caregivers: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Li, Yan-Wei; Zhou, Le-Shan; Li, Xing

    2017-03-15

    Fever is the most common complaint in the pediatric and emergency departments. Caregivers prefer to detect fever in their children by tactile assessment. To summarize the evidence on the accuracy of caregivers' tactile assessment for detecting fever in children. We performed a literature search of Cochrane Library, PubMed, Web of Knowledge, EMBASE (ovid), EBSCO and Google Scholar, without restriction of publication date, to identify English articles assessing caregivers' ability of detecting fever in children by tactile assessment. Quality assessment was based on the 2011 Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. Pooled estimates of sensitivity and specificity were calculated with use of bivariate model and summary receiver operation characteristics plots for meta-analysis. 11 articles were included in our analysis. The summary estimates for tactile assessment as a diagnostic tool revealed a sensitivity of 87.5% (95% CI 79.3% to 92.8%) and specificity of 54.6% (95% CI 38.5% to 69.9%). The pooled positive likelihood ratio was 1.93 (95% CI 1.39 to 2.67) and negative likelihood ratio was 0.23 (95% CI 0.15 to 0.36). Area under curve was 0.82 (95% CI 0.7 to 0.85). The pooled diagnostic odds ratio was 8.46 (95% CI 4.54 to 15.76). Tactile assessment of fever in children by palpation has moderate diagnostic value. Caregivers' assessment as "no fever" by touch is quite accurate in ruling out fever, while assessment as "fever" can be considered but needs confirmation.

  14. Tactile and non-tactile sensory paradigms for fMRI and neurophysiologic studies in rodents.

    Science.gov (United States)

    Sanganahalli, Basavaraju G; Bailey, Christopher J; Herman, Peter; Hyder, Fahmeed

    2009-01-01

    Functional magnetic resonance imaging (fMRI) has become a popular functional imaging tool for human studies. Future diagnostic use of fMRI depends, however, on a suitable neurophysiologic interpretation of the blood oxygenation level dependent (BOLD) signal change. This particular goal is best achieved in animal models primarily due to the invasive nature of other methods used and/or pharmacological agents applied to probe different nuances of neuronal (and glial) activity coupled to the BOLD signal change. In the last decade, we have directed our efforts towards the development of stimulation protocols for a variety of modalities in rodents with fMRI. Cortical perception of the natural world relies on the formation of multi-dimensional representation of stimuli impinging on the different sensory systems, leading to the hypothesis that a sensory stimulus may have very different neurophysiologic outcome(s) when paired with a near simultaneous event in another modality. Before approaching this level of complexity, reliable measures must be obtained of the relatively small changes in the BOLD signal and other neurophysiologic markers (electrical activity, blood flow) induced by different peripheral stimuli. Here we describe different tactile (i.e., forepaw, whisker) and non-tactile (i.e., olfactory, visual) sensory paradigms applied to the anesthetized rat. The main focus is on development and validation of methods for reproducible stimulation of each sensory modality applied independently or in conjunction with one another, both inside and outside the magnet. We discuss similarities and/or differences across the sensory systems as well as advantages they may have for studying essential neuroscientific questions. We envisage that the different sensory paradigms described here may be applied directly to studies of multi-sensory interactions in anesthetized rats, en route to a rudimentary understanding of the awake functioning brain where various sensory cues presumably

  15. Inducing circular vection with tactile stimulation encircling the waist

    NARCIS (Netherlands)

    Tinga, A.M.; Jansen, C.; Smagt, M.J. van der; Nijboer, T.C.W.; Erp, J.B.F. van

    2018-01-01

    In general, moving sensory stimuli (visual and auditory) can induce illusory sensations of self-motion (i.e. vection) in the direction opposite of the sensory stimulation. The aim of the current study was to examine whether tactile stimulation encircling the waist could induce circular vection

  16. Tribotronic Transistor Array as an Active Tactile Sensing System.

    Science.gov (United States)

    Yang, Zhi Wei; Pang, Yaokun; Zhang, Limin; Lu, Cunxin; Chen, Jian; Zhou, Tao; Zhang, Chi; Wang, Zhong Lin

    2016-12-27

    Large-scale tactile sensor arrays are of great importance in flexible electronics, human-robot interaction, and medical monitoring. In this paper, a flexible 10 × 10 tribotronic transistor array (TTA) is developed as an active tactile sensing system by incorporating field-effect transistor units and triboelectric nanogenerators into a polyimide substrate. The drain-source current of each tribotronic transistor can be individually modulated by the corresponding external contact, which has induced a local electrostatic potential to act as the conventional gate voltage. By scaling down the pixel size from 5 × 5 to 0.5 × 0.5 mm 2 , the sensitivities of single pixels are systematically investigated. The pixels of the TTA show excellent durability, independence, and synchronicity, which are suitable for applications in real-time tactile sensing, motion monitoring, and spatial mapping. The integrated tribotronics provides an unconventional route to realize an active tactile sensing system, with prospective applications in wearable electronics, human-machine interfaces, fingerprint identification, and so on.

  17. The TaSST: Tactile sleeve for social touch

    NARCIS (Netherlands)

    Huisman, Gijs; Darriba Frederiks, Aduén; van Dijk, Elisabeth M.A.G.; Heylen, Dirk K.J.; Krose, Ben

    In this paper we outline the design process of the TaSST (Tactile Sleeve for Social Touch), a touch-sensitive vibrotactile arm sleeve. The TaSST was designed to enable two people to communicate different types of touch over a distance. The touch-sensitive surface of the sleeve consists of a grid of

  18. Early vision impairs tactile perception in the blind.

    Science.gov (United States)

    Röder, Brigitte; Rösler, Frank; Spence, Charles

    2004-01-20

    Researchers have known for more than a century that crossing the hands can impair both tactile perception and the execution of appropriate finger movements. Sighted people find it more difficult to judge the temporal order when two tactile stimuli, one applied to either hand, are presented and their hands are crossed over the midline as compared to when they adopt a more typical uncrossed-hands posture. It has been argued that because of the dominant role of vision in motor planning and execution, tactile stimuli are remapped into externally defined coordinates (predominantly determined by visual inputs) that takes longer to achieve when external and body-centered codes (determined primarily by somatosensory/proprioceptive inputs) are in conflict and that involves both multisensory parietal and visual cortex. Here, we show that the performance of late, but not of congenitally, blind people was impaired by crossing the hands. Moreover, we provide the first empirical evidence for superior temporal order judgments (TOJs) for tactile stimuli in the congenitally blind. These findings suggest a critical role of childhood vision in modulating the perception of touch that may arise from the emergence of specific crossmodal links during development.

  19. Tactile short-term memory in sensory-deprived individuals.

    Science.gov (United States)

    Papagno, Costanza; Minniti, Giovanna; Mattavelli, Giulia C; Mantovan, Lara; Cecchetto, Carlo

    2017-02-01

    To verify whether loosing a sense or two has consequences on a spared sensory modality, namely touch, and whether these consequences depend on practice or are biologically determined, we investigated 13 deafblind participants, 16 deaf participants, 15 blind participants, and 13 matched normally sighted and hearing controls on a tactile short-term memory task, using checkerboard matrices of increasing length in which half of the squares were made up of a rough texture and half of a smooth one. Time of execution of a fixed matrix, number of correctly reproduced matrices, largest matrix correctly reproduced and tactile span were recorded. The three groups of sensory-deprived individuals did not differ in any measure, while blind and deaf participants outscored controls in all parameters except time of execution; the difference approached significance for deafblind people compared to controls only in one measure, namely correctly reproduced matrices. In blind and deafblind participants, performance negatively correlated with age of Braille acquisition, the older being the subject when acquiring Braille, the lower the performance, suggesting that practice plays a role. However, the fact that deaf participants, who did not share tactile experience, performed similarly to blind participants and significantly better than controls highlights that practice cannot be the only contribution to better tactile memory.

  20. Bilateral Symmetry of Distortions of Tactile Size Perception.

    Science.gov (United States)

    Longo, Matthew R; Ghosh, Arko; Yahya, Tasneem

    2015-01-01

    The perceived distance between touches on the limbs is generally bigger for distances oriented across the width of the limb than for distances oriented along the length of the limb. The present study aimed to investigate the coherence of such distortions of tactile size perception across different skin surfaces. We investigated distortions of tactile size perception on the dorsal and palmar surfaces of both the left and right hands as well as the forehead. Participants judged which of two tactile distances felt larger. One distance was aligned with the proximodistal axis (along the body), the other with the mediolateral axis (across the body). Clear distortions were found on all five skin surfaces, with stimuli oriented across the width of the body being perceived as farther apart than those oriented along the length of the body. Consistent with previous results, distortions were smaller on the palmar than on the dorsal hand surface. Distortion on the forehead was intermediate between the dorsal and palmar surfaces. There were clear correlations between distortion on the left and right hands, for both the dorsal and palmar skin surfaces. In contrast, within each hand, there was no significant correlation between the two skin surfaces. Distortion on the forehead was not significantly correlated with that on any of the other skin surfaces. These results provide evidence for bilaterally symmetric representations underlying tactile size perception. © The Author(s) 2015.

  1. High Resolution Tactile Sensors for Curved Robotic Fingertips

    DEFF Research Database (Denmark)

    Drimus, Alin; Jankovics, Vince; Gorsic, Matija

    2014-01-01

    Tactile sensing is a key element for various animals that interact with the environment and surrounding objects. Touch provides information about contact forces, torques and pressure distribution and by the means of exploration it provides object properties such as geometry, stiffness and texture[5...

  2. Hybrid-Actuated Finger Prosthesis with Tactile Sensing

    Directory of Open Access Journals (Sweden)

    Cheng Yee Low

    2013-10-01

    Full Text Available Finger prostheses are devices developed to emulate the functionality of natural human fingers. On top of their aesthetic appearance in terms of shape, size and colour, such biomimetic devices require a high level of dexterity. They must be capable of gripping an object, and even manipulating it in the hand. This paper presents a biomimetic robotic finger actuated by a hybrid mechanism and integrated with a tactile sensor. The hybrid actuation mechanism comprises a DC micromotor and a Shape Memory Alloy (SMA wire. A customized test rig has been developed to measure the force and stroke produced by the SMA wire. In parallel with the actuator development, experimental investigations have been conducted on Quantum Tunnelling Composite (QTC and Pressure Conductive Rubber (PCR towards the development of a tactile sensor for the finger. The viability of using these materials for tactile sensing has been determined. Such a hybrid actuation approach aided with tactile sensing capability enables a finger design as an integral part of a prosthetic hand for applications up to the transradial amputation level.

  3. Gender difference in premotor activity during active tactile discrimination.

    Science.gov (United States)

    Sadato, N; Ibañez, V; Deiber, M P; Hallett, M

    2000-05-01

    To investigate possible gender differences in tactile discrimination tasks, we measured cerebral blood flow of seven men and seven women using positron emission tomography and (15)O water during tactile tasks performed with the right index finger. A nondiscrimination, somatosensory control task activated the left primary sensorimotor cortex and the left parietal operculum extending to the posterior insula without any gender difference. Compared with the control task, discrimination tasks activated the superior and inferior parietal lobules bilaterally, right dorsal premotor cortex, and dorsolateral prefrontal cortex in both genders, consistent with the notion of right hemisphere involvement during exploratory attentional movements. In both genders, symmetric activation of the superior and inferior parietal lobules and asymmetric activation of the right dorsolateral prefrontal cortex were confirmed. The former is consistent with the spatial representation of the tactile input and the latter with the spatial working memory. However, activation of the dorsal premotor cortex was asymmetric in men, whereas it was symmetric in women, the gender difference being statistically significant. This may suggest gender differences in motor programs for exploration in manipulospatial tasks such as tactile discrimination with active touch, possibly by greater interhemispheric interaction through the dorsal premotor cortices in women than in men. Copyright 2000 Academic Press.

  4. Crossmodal Congruency Benefits for Tactile and Visual Signaling

    Science.gov (United States)

    2008-10-01

    above along with their controller box. The tactors are operated using a Tactor Control Unit ( TCU ) which is a computer-controlled driver/amplifier...system that switches each tactor on and off as required. This device is shown on the left side of the tactile displays belts in Figure 1. The TCU

  5. Remote tactile sensing system integrated with magnetic synapse.

    Science.gov (United States)

    Oh, Sunjong; Jung, Youngdo; Kim, Seonggi; Kim, SungJoon; Hu, Xinghao; Lim, Hyuneui; Kim, CheolGi

    2017-12-05

    Mechanoreceptors in a fingertip convert external tactile stimulations into electrical signals, which are transmitted by the nervous system through synaptic transmitters and then perceived by the brain with high accuracy and reliability. Inspired by the human synapse system, this paper reports a robust tactile sensing system consisting of a remote touch tip and a magnetic synapse. External pressure on the remote touch tip is transferred in the form of air pressure to the magnetic synapse, where its variation is converted into electrical signals. The developed system has high sensitivity and a wide dynamic range. The remote sensing system demonstrated tactile capabilities over wide pressure range with a minimum detectable pressure of 6 Pa. In addition, it could measure tactile stimulation up to 1,000 Hz without distortion and hysteresis, owing to the separation of the touching and sensing parts. The excellent performance of the system in terms of surface texture discrimination, heartbeat measurement from the human wrist, and satisfactory detection quality in water indicates that it has considerable potential for various mechanosensory applications in different environments.

  6. Tactile Assessment in Children with Cerebral Palsy: A Clinimetric Review

    Science.gov (United States)

    Auld, Megan Louise; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2011-01-01

    This review evaluates the clinimetric properties of tactile assessments for children with cerebral palsy. Assessment of registration was reported using Semmes Weinstein Monofilaments (SWMs) or exteroception. Assessment of two-point discrimination was reported using the Disk-Criminator[R] or paperclip methods; Single point localization and double…

  7. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    Science.gov (United States)

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  8. To What Extent Do Gestalt Grouping Principles Influence Tactile Perception?

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2011-01-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli.…

  9. Small-scale tactile graphics for virtual reality systems

    Science.gov (United States)

    Roberts, John W.; Slattery, Oliver T.; Swope, Brett; Min, Volker; Comstock, Tracy

    2002-05-01

    As virtual reality technology moves forward, there is a need to provide the user with options for greater realism for closer engagement to the human senses. Haptic systems use force feedback to create a large-scale sensation of physical interaction in a virtual environment. Further refinement can be created by using tactile graphics to reproduce a detailed sense of touch. For example, a haptic system might create the sensation of the weight of a virtual orange that the user picks up, and the sensation of pressure on the fingers as the user squeezes the orange. A tactile graphic system could create the texture of the orange on the user's fingertips. IN the real wold, a detailed sense of touch plays a large part in picking up and manipulating small objects. Our team is working to develop technology that can drive a high density fingertip array of tactile simulators at a rapid refresh rate, sufficient to produce a realistic sense of touch. To meet the project criteria, the mechanism must be much lower cost than existing technologies, and must be sufficiently lightweight and compact to permit portable use and to enable installation of the stimulator array in the fingertip of a tactile glove. The primary intended applications for this technology are accessibility for the blind and visually impaired, teleoperation, and virtual reality systems.

  10. The TaSST: Tactile Sleeve for Social Touch

    NARCIS (Netherlands)

    Huisman, G.; Darriba Frederiks, A.; van Dijk, B.; Heylen, D.; Kröse, B.

    2013-01-01

    In this paper we outline the design process of the TaSST (Tactile Sleeve for Social Touch), a touch-sensitive vibrotactile arm sleeve. The TaSST was designed to enable two people to communicate different types of touch over a distance. The touch-sensitive surface of the sleeve consists of a grid of

  11. The TaSST - Tactile Sleeve for Social Touch

    NARCIS (Netherlands)

    Huisman, Gijs; Darriba Frederiks, Aduén; Van Dijk, Betsy; Heylen, Dirk

    2013-01-01

    In this paper we outline the design process of TaSST (Tactile Sleeve for Social Touch), a touch-sensitive vibrotactile arm sleeve. The TaSST was designed to enable two people to communicate different types of touches over a distance. The touch-sensitive surface of the sleeve consists of a grid of

  12. About Face: Evaluating and Managing Tactile Impairment at the Time of Autism Diagnosis

    Directory of Open Access Journals (Sweden)

    Louisa M. T. Silva

    2015-01-01

    Full Text Available Evaluation for sensory impairment is a routine part of autism diagnosis. Sensory impairment of hearing, vision, or touch results in developmental delay and must be addressed before delay can resolve. Recent studies confirm that tactile impairment is present in autism and can be effectively treated with a tactile stimulation protocol. The research suggests a change in management at the time of autism diagnosis to include evaluation and treatment of tactile impairment. Here we validate screening and management tool for tactile impairment, the Autism Touch and Self-Regulation Checklist, in 404 typical and autistic preschool children. The tool assesses tactile impairment by location and severity. Autistic children were distinguished by mixed pain and numbness on multiple areas including the face and mouth (F=412.1 (1,402;p<.000. Oral-facial tactile impairment interferes with the tactile stimulus to orienting. We hypothesized that oral-facial tactile impairment and difficulty orienting are predictive of ASD and that severity of tactile impairment is predictive of severity of ASD. Questions evaluating oral-facial and orienting responses correctly predicted 91% of the autism group. Severity of tactile impairment correctly predicted 81% of mild versus severe ASD. Results underscore the importance of evaluating and treating tactile impairment at the time of autism diagnosis.

  13. Tactile sensibility of single-tooth implants and natural teeth.

    Science.gov (United States)

    Enkling, Norbert; Nicolay, Claudia; Utz, Karl-Heinz; Jöhren, Peter; Wahl, Gerhard; Mericske-Stern, Regina

    2007-04-01

    The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between single-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison). The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 microm) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution. The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7+/-11.3 microm (0.6-53.1 microm); natural tooth/natural tooth: 14.3+/-10.6 microm (0.5-68.2 microm)]. The intraindividual differences only amounted to a mean value of 2.4+/-9.4 microm (-15.1 to 27.5 microm). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/-8 microm, P80%). Hence, the implants could be integrated in the stomatognathic control circuit.

  14. Integration of Fiber-Optic Sensor Arrays into a Multi-Modal Tactile Sensor Processing System for Robotic End-Effectors

    Science.gov (United States)

    Kampmann, Peter; Kirchner, Frank

    2014-01-01

    With the increasing complexity of robotic missions and the development towards long-term autonomous systems, the need for multi-modal sensing of the environment increases. Until now, the use of tactile sensor systems has been mostly based on sensing one modality of forces in the robotic end-effector. The use of a multi-modal tactile sensory system is motivated, which combines static and dynamic force sensor arrays together with an absolute force measurement system. This publication is focused on the development of a compact sensor interface for a fiber-optic sensor array, as optic measurement principles tend to have a bulky interface. Mechanical, electrical and software approaches are combined to realize an integrated structure that provides decentralized data pre-processing of the tactile measurements. Local behaviors are implemented using this setup to show the effectiveness of this approach. PMID:24743158

  15. Integration of fiber-optic sensor arrays into a multi-modal tactile sensor processing system for robotic end-effectors.

    Science.gov (United States)

    Kampmann, Peter; Kirchner, Frank

    2014-04-16

    With the increasing complexity of robotic missions and the development towards long-term autonomous systems, the need for multi-modal sensing of the environment increases. Until now, the use of tactile sensor systems has been mostly based on sensing one modality of forces in the robotic end-effector. The use of a multi-modal tactile sensory system is motivated, which combines static and dynamic force sensor arrays together with an absolute force measurement system. This publication is focused on the development of a compact sensor interface for a fiber-optic sensor array, as optic measurement principles tend to have a bulky interface. Mechanical, electrical and software approaches are combined to realize an integrated structure that provides decentralized data pre-processing of the tactile measurements. Local behaviors are implemented using this setup to show the effectiveness of this approach.

  16. Integration of Fiber-Optic Sensor Arrays into a Multi-Modal Tactile Sensor Processing System for Robotic End-Effectors

    Directory of Open Access Journals (Sweden)

    Peter Kampmann

    2014-04-01

    Full Text Available With the increasing complexity of robotic missions and the development towards long-term autonomous systems, the need for multi-modal sensing of the environment increases. Until now, the use of tactile sensor systems has been mostly based on sensing one modality of forces in the robotic end-effector. The use of a multi-modal tactile sensory system is motivated, which combines static and dynamic force sensor arrays together with an absolute force measurement system. This publication is focused on the development of a compact sensor interface for a fiber-optic sensor array, as optic measurement principles tend to have a bulky interface. Mechanical, electrical and software approaches are combined to realize an integrated structure that provides decentralized data pre-processing of the tactile measurements. Local behaviors are implemented using this setup to show the effectiveness of this approach.

  17. An insect-inspired bionic sensor for tactile localization and material classification with state-dependent modulation

    OpenAIRE

    Patanè, Luca; Hellbach, Sven; Krause, André F.; Arena, Paolo; Dürr, Volker

    2012-01-01

    Insects carry a pair of antennae on their head: multimodal sensory organs that serve a wide range of sensory-guided behaviors. During locomotion, antennae are involved in near-range orientation, for example in detecting, localizing, probing, and negotiating obstacles. Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped...

  18. Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring.

    Science.gov (United States)

    Gao, Yuji; Ota, Hiroki; Schaler, Ethan W; Chen, Kevin; Zhao, Allan; Gao, Wei; Fahad, Hossain M; Leng, Yonggang; Zheng, Anzong; Xiong, Furui; Zhang, Chuchu; Tai, Li-Chia; Zhao, Peida; Fearing, Ronald S; Javey, Ali

    2017-10-01

    Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for applications such as heart-rate monitoring, which require a much lower pressure detection resolution. In this paper, a microfluidic tactile diaphragm pressure sensor based on embedded Galinstan microchannels (70 µm width × 70 µm height) capable of resolving sub-50 Pa changes in pressure with sub-100 Pa detection limits and a response time of 90 ms is demonstrated. An embedded equivalent Wheatstone bridge circuit makes the most of tangential and radial strain fields, leading to high sensitivities of a 0.0835 kPa -1 change in output voltage. The Wheatstone bridge also provides temperature self-compensation, allowing for operation in the range of 20-50 °C. As examples of potential applications, a polydimethylsiloxane (PDMS) wristband with an embedded microfluidic diaphragm pressure sensor capable of real-time pulse monitoring and a PDMS glove with multiple embedded sensors to provide comprehensive tactile feedback of a human hand when touching or holding objects are demonstrated. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. White matter microstructure is associated with auditory and tactile processing in children with and without sensory processing disorder

    Directory of Open Access Journals (Sweden)

    Yi Shin Chang

    2016-01-01

    Full Text Available Sensory processing disorders (SPD affect up to 16% of school-aged children, and contribute to cognitive and behavioral deficits impacting affected individuals and their families. While sensory processing differences are now widely recognized in children with autism, children with sensory-based dysfunction who do not meet autism criteria based on social communication deficits remain virtually unstudied. In a previous pilot diffusion tensor imaging (DTI study, we demonstrated that boys with SPD have altered white matter microstructure primarily affecting the posterior cerebral tracts, which subserve sensory processing and integration. This disrupted microstructural integrity, measured as reduced white matter fractional anisotropy (FA, correlated with parent report measures of atypical sensory behavior. In this present study, we investigate white matter microstructure as it relates to tactile and auditory function in depth with a larger, mixed-gender cohort of children 8 to 12 years of age. We continue to find robust alterations of posterior white matter microstructure in children with SPD relative to typically developing children, along with more spatially distributed alterations. We find strong correlations of FA with both parent report and direct measures of tactile and auditory processing across children, with the direct assessment measures of tactile and auditory processing showing a stronger and more continuous mapping to the underlying white matter integrity than the corresponding parent report measures. Based on these findings of microstructure as a neural correlate of sensory processing ability, diffusion MRI merits further investigation as a tool to find biomarkers for diagnosis, prognosis and treatment response in children with SPD. To our knowledge, this work is the first to demonstrate associations of directly measured tactile and non-linguistic auditory function with white matter microstructural integrity -- not just in children with

  20. White Matter Microstructure is Associated with Auditory and Tactile Processing in Children with and without Sensory Processing Disorder.

    Science.gov (United States)

    Chang, Yi-Shin; Gratiot, Mathilde; Owen, Julia P; Brandes-Aitken, Anne; Desai, Shivani S; Hill, Susanna S; Arnett, Anne B; Harris, Julia; Marco, Elysa J; Mukherjee, Pratik

    2015-01-01

    Sensory processing disorders (SPDs) affect up to 16% of school-aged children, and contribute to cognitive and behavioral deficits impacting affected individuals and their families. While sensory processing differences are now widely recognized in children with autism, children with sensory-based dysfunction who do not meet autism criteria based on social communication deficits remain virtually unstudied. In a previous pilot diffusion tensor imaging (DTI) study, we demonstrated that boys with SPD have altered white matter microstructure primarily affecting the posterior cerebral tracts, which subserve sensory processing and integration. This disrupted microstructural integrity, measured as reduced white matter fractional anisotropy (FA), correlated with parent report measures of atypical sensory behavior. In this present study, we investigate white matter microstructure as it relates to tactile and auditory function in depth with a larger, mixed-gender cohort of children 8-12 years of age. We continue to find robust alterations of posterior white matter microstructure in children with SPD relative to typically developing children (TDC), along with more spatially distributed alterations. We find strong correlations of FA with both parent report and direct measures of tactile and auditory processing across children, with the direct assessment measures of tactile and auditory processing showing a stronger and more continuous mapping to the underlying white matter integrity than the corresponding parent report measures. Based on these findings of microstructure as a neural correlate of sensory processing ability, diffusion MRI merits further investigation as a tool to find biomarkers for diagnosis, prognosis and treatment response in children with SPD. To our knowledge, this work is the first to demonstrate associations of directly measured tactile and non-linguistic auditory function with white matter microstructural integrity - not just in children with SPD, but also

  1. [Short-term memory characteristics of vibration intensity tactile perception on human wrist].

    Science.gov (United States)

    Hao, Fei; Chen, Li-Juan; Lu, Wei; Song, Ai-Guo

    2014-12-25

    In this study, a recall experiment and a recognition experiment were designed to assess the human wrist's short-term memory characteristics of tactile perception on vibration intensity, by using a novel homemade vibrotactile display device based on the spatiotemporal combination vibration of multiple micro vibration motors as a test device. Based on the obtained experimental data, the short-term memory span, recognition accuracy and reaction time of vibration intensity were analyzed. From the experimental results, some important conclusions can be made: (1) The average short-term memory span of tactile perception on vibration intensity is 3 ± 1 items; (2) The greater difference between two adjacent discrete intensities of vibrotactile stimulation is defined, the better average short-term memory span human wrist gets; (3) There is an obvious difference of the average short-term memory span on vibration intensity between the male and female; (4) The mechanism of information extraction in short-term memory of vibrotactile display is to traverse the scanning process by comparison; (5) The recognition accuracy and reaction time performance of vibrotactile display compares unfavourably with that of visual and auditory. The results from this study are important for designing vibrotactile display coding scheme.

  2. Tactile Sensor Array with Fiber Bragg Gratings in Quasi-Distributed Sensing

    Directory of Open Access Journals (Sweden)

    Marcelo A. Pedroso

    2018-01-01

    Full Text Available This work describes the development of a quasi-distributed real-time tactile sensing system with a reduced number of fiber Bragg grating-based sensors and reports its use with a reconstruction method based on differential evolution. The sensing system is comprised of six fiber Bragg gratings encapsulated in silicone elastomer to form a tactile sensor array with total dimensions of 60 × 80 mm, divided into eight sensing cells with dimensions of 20 × 30 mm. Forces applied at the central position of the sensor array resulted in linear response curves for the gratings, highlighting their coupled responses and allowing the application of compressive sensing. The reduced number of sensors regarding the number of sensing cells results in an undetermined inverse problem, solved with a compressive sensing algorithm with the aid of differential evolution method. The system is capable of identifying and quantifying up to four different loads at four different cells with relative errors lower than 10.5% and signal-to-noise ratio better than 12 dB.

  3. A Magnetoresistive Tactile Sensor for Harsh Environment Applications

    Directory of Open Access Journals (Sweden)

    Ahmed Alfadhel

    2016-05-01

    Full Text Available A magnetoresistive tactile sensor is reported, which is capable of working in high temperatures up to 140 °C. Hair-like bioinspired structures, known as cilia, made out of permanent magnetic nanocomposite material on top of spin-valve giant magnetoresistive (GMR sensors are used for tactile sensing at high temperatures. The magnetic nanocomposite, consisting of iron nanowires incorporated into the polymer polydimethylsiloxane (PDMS, is very flexible, biocompatible, has high remanence, and is also resilient to antagonistic sensing ambient. When the cilia come in contact with a surface, they deflect in compliance with the surface topology. This yields a change of the GMR sensor signal, enabling the detection of extremely fine features. The spin-valve is covered with a passivation layer, which enables adequate performance in spite of harsh environmental conditions, as demonstrated in this paper for high temperature.

  4. A Magnetoresistive Tactile Sensor for Harsh Environment Applications

    KAUST Repository

    Alfadhel, Ahmed

    2016-05-07

    A magnetoresistive tactile sensor is reported, which is capable of working in high temperatures up to 140 °C. Hair-like bioinspired structures, known as cilia, made out of permanent magnetic nanocomposite material on top of spin-valve giant magnetoresistive (GMR) sensors are used for tactile sensing at high temperatures. The magnetic nanocomposite, consisting of iron nanowires incorporated into the polymer polydimethylsiloxane (PDMS), is very flexible, biocompatible, has high remanence, and is also resilient to antagonistic sensing ambient. When the cilia come in contact with a surface, they deflect in compliance with the surface topology. This yields a change of the GMR sensor signal, enabling the detection of extremely fine features. The spin-valve is covered with a passivation layer, which enables adequate performance in spite of harsh environmental conditions, as demonstrated in this paper for high temperature.

  5. Mid-Air Tactile Stimulation Using Indirect Laser Radiation.

    Science.gov (United States)

    Lee, Hojin; Kim, Ji-Sun; Kim, Jae-Young; Choi, Seungmoon; Jun, Jae-Hoon; Park, Jong-Rak; Kim, A-Hee; Oh, Han-Byeol; Baek, Jun-Hyeok; Yang, Seung-Jin; Kim, Hyung-Sik; Chung, Soon-Cheol

    2016-01-01

    In this paper, we demonstrate that a laser irradiated on a thin light-absorbing elastic medium attached on the skin can elicit a tactile sensation of mechanical tap. First, we present simulation results that show laser irradiation to the elastic medium creates inner elastic waves on the basis of thermoelastic effects and these elastic waves trigger the bending deformation of the medium, which then stimulates the skin. Second, we analyze the physical properties of the associated stimulus by measuring its force profile. Third, we identify the perceptual characteristics of the stimulus in comparison to those of mechanical and electrical stimuli by means of a perceptual experiment employing dissimilarity rating. All the evidence indicates that indirect laser radiation provides a sensation of short mechanical tap. Furthermore, little individual difference was observed in the results of the perceptual experiment. To the best of our knowledge, this study is the first in reporting the feasibility of indirect laser radiation for mid-air tactile rendering.

  6. Vision merges with touch in a purely tactile discrimination.

    Science.gov (United States)

    Arabzadeh, Ehsan; Clifford, Colin W G; Harris, Justin A

    2008-07-01

    To construct a coherent percept of the world, the brain continuously combines information across multiple sensory modalities. Simple stimuli from different modalities are usually assumed to be processed in distinct brain areas. However, there is growing evidence that simultaneous stimulation of multiple modalities can influence the activity in unimodal sensory areas and improve or impair performance in unimodal tasks. Do these effects reflect a genuine cross-modal integration of sensory signals, or are they due to changes in the perceiver's ability to locate the stimulus in time and space? We used a behavioral measure to differentiate between these explanations. Our results demonstrate that, under certain circumstances, a noninformative flash of light can have facilitative or detrimental effects on a simple tactile discrimination. The effect of the visual flash mimics that produced by a constant tactile pedestal stimulus. These findings reveal that sensory signals from different modalities can be integrated, even for perceptual judgments within a single modality.

  7. Manual command component with tactile and/or kinesthetic feedback

    International Nuclear Information System (INIS)

    Foumier, R.

    1995-01-01

    The invention concerns a manual command component designed to be use by a human hand in order to control a slave system, with a tactile and/or kinesthetic feedback. It is composed by a handle and by piece(s) for the feedback. The handle contains a captor to signalize the move and the speed. The signals are transmitted to the slave system. The later send feedbacks which are transformed in a couple for the handle. (TEC)

  8. Muscle: The Tactile Texture Designed for the Blind

    OpenAIRE

    Chantana Insra

    2014-01-01

    The research objective focuses on creating a prototype media of the tactile texture of muscles for educational institutes to help visually impaired students learn massage extra learning materials further than the ordinary curriculum. This media is designed as an extra learning material. The population in this study was 30 blinded students between 4th - 6th grades who were able to read Braille language. The research was conducted during the second semester in 2012 at The B...

  9. Audio-Tactile Integration and the Influence of Musical Training

    OpenAIRE

    Kuchenbuch, Anja; Paraskevopoulos, Evangelos; Herholz, Sibylle C.; Pantev, Christo

    2014-01-01

    Perception of our environment is a multisensory experience; information from different sensory systems like the auditory, visual and tactile is constantly integrated. Complex tasks that require high temporal and spatial precision of multisensory integration put strong demands on the underlying networks but it is largely unknown how task experience shapes multisensory processing. Long-term musical training is an excellent model for brain plasticity because it shapes the human brain at function...

  10. Active tactile exploration using a brain-machine-brain interface.

    Science.gov (United States)

    O'Doherty, Joseph E; Lebedev, Mikhail A; Ifft, Peter J; Zhuang, Katie Z; Shokur, Solaiman; Bleuler, Hannes; Nicolelis, Miguel A L

    2011-10-05

    Brain-machine interfaces use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. It is hoped that brain-machine interfaces can be used to restore the normal sensorimotor functions of the limbs, but so far they have lacked tactile sensation. Here we report the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and allows signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex. Monkeys performed an active exploration task in which an actuator (a computer cursor or a virtual-reality arm) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in the primary motor cortex. ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search for and distinguish one of three visually identical objects, using the virtual-reality arm to identify the unique artificial texture associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic or even virtual prostheses.

  11. Illusory touch and tactile perception in somatoform dissociators.

    Science.gov (United States)

    Brown, Richard J; Brunt, Natalie; Poliakoff, Ellen; Lloyd, Donna M

    2010-09-01

    The psychological mechanisms of somatoform dissociation (i.e., pseudoneurological symptoms) are poorly understood. This study evaluated recent theoretical predictions regarding the role of tactile perception in the development of somatoform dissociative symptoms. Eighty nonclinical participants scoring either high or low on the Somatoform Dissociation Questionnaire (SDQ-20) completed the Somatic Signal Detection Task (SSDT), a novel perceptual paradigm designed to simulate the occurrence of somatoform symptoms in the laboratory. Prior to the SSDT, participants completed a memory task designed to produce either minimal or maximal activation of tactile representations in memory. The high SDQ-20 group exhibited a more liberal response criterion (c) on the SSDT than the low SDQ-20 group after controlling for negative affectivity, somatosensory amplification and depression. This effect was mainly attributable to an increased number of false alarms (i.e., illusory experiences of touch) in the high SDQ-20 group rather than an increased hit rate. General perceptual ability (i.e., tactile sensitivity) was comparable between the two groups. The memory manipulation had no effect on SSDT performance. Somatoform dissociators appear more likely to experience illusory perceptual events under conditions of sensory ambiguity than nondissociators, despite comparable perceptual abilities more generally. These findings support theories that identify distorted perceptual processing as a feature of somatoform dissociation. The SSDT has potential as a tool for further research in this area. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  12. Arborealities: The Tactile Ecology of Hardy’s Woodlanders

    Directory of Open Access Journals (Sweden)

    William A. Cohen

    2014-10-01

    Full Text Available This article asks what consequences two recent movements in scholarship - affect theory and environmental studies - might have for understanding the Victorian tactile imagination. Thomas Hardy's 1887 novel 'The Woodlanders' provides a means of addressing this question, for it shares with posthumanist critics a view that people are material things in a world of things, and that the world is itself a collection of vital agencies and networked actors. Hardy shows how a tactile modality provides a point of entry into discussions of both affect and ecology, situating the human in a proximate, contiguous relation to both bodily and environmental materialities. 'The Woodlanders' offers a world in which trees, in particular, work on - and are in turn worked on by - human objects; a world in which, one might say, the trees are people and the people are trees. This arboreality is far from a sentimental oneness with nature, nor is it an exercise in anthropomorphization. Instead, it provides a recognition of the inhuman, material, and sensate aspects of the human; or, perhaps better, of the human as rooted, budding, leafy, and abloom. Like some recent theoretical accounts, 'The Woodlanders' disperses agency among human and non-human elements alike, employing a tactile mode of representation to break down distinctions between them. Normal 0 false false false EN-US X-NONE X-NONE

  13. Spine Posture Influences Tactile Perceptual Sensitivity of the Trunk Dorsum.

    Science.gov (United States)

    Beaudette, Shawn M; Smith, Simone G V S; Bent, Leah R; Brown, Stephen H M

    2017-12-01

    The purpose of the current work was to quantify the influence of posture-mediated skin deformation on trunk dorsum tactile perceptual sensitivity. Twelve young and healthy individuals were assessed while adopting three different spine postures (extension, neutral and flexion). Tactile sensitivity threshold tests (T10 and L4 vertebral levels) included measures of touch sensitivity, spatial acuity and stretch sensitivity. The results demonstrate that tactile sensitivity can differ due to changes in body posture. The skin of the trunk dorsum had increased thresholds for touch sensitivity, longitudinal spatial acuity and transverse stretch sensitivity in spine flexion. Furthermore, spine flexion also resulted in a reduced sensory threshold to stretching stimuli in the longitudinal direction. The opposite trends occurred when participants adopted spine extension. It is suggested that posture-mediated skin deformation generates changes in the amount of strain experienced by individual skin mechanoreceptors, and the relative spacing between mechanoreceptors. Furthermore, it is suggested that "pre-stretch" of the skin brings mechanoreceptors closer to their stretch activation thresholds, thereby increasing an individual's sensitivity to skin stretch when in spine flexion.

  14. Improved tactile resonance sensor for robotic assisted surgery

    Science.gov (United States)

    Oliva Uribe, David; Schoukens, Johan; Stroop, Ralf

    2018-01-01

    This paper presents an improved tactile sensor using a piezoelectric bimorph able to differentiate soft materials with similar mechanical characteristics. The final aim is to develop intelligent surgical tools for brain tumour resection using integrated sensors in order to improve tissue tumour delineation and tissue differentiation. The bimorph sensor is driven using a random phase multisine and the properties of contact between the sensor's tip and a certain load are evaluated by means of the evaluation of the nonparametric FRF. An analysis of the nonlinear contributions is presented to show that the use of a linear model is feasible for the measurement conditions. A series of gelatine phantoms were tested. The tactile sensor is able to identify minimal differences in the consistency of the measured samples considering viscoelastic behaviour. A variance analysis was performed to evaluate the reliability of the sensors and to identify possible error sources due to inconsistencies in the preparation method of the phantoms. The results of the variance analysis are discussed showing that ability of the proposed tactile sensor to perform high quality measurements.

  15. Shared and Divergent Auditory and Tactile Processing in Children with Autism and Children with Sensory Processing Dysfunction Relative to Typically Developing Peers.

    Science.gov (United States)

    Demopoulos, Carly; Brandes-Aitken, Annie N; Desai, Shivani S; Hill, Susanna S; Antovich, Ashley D; Harris, Julia; Marco, Elysa J

    2015-07-01

    The aim of this study was to compare sensory processing in typically developing children (TDC), children with Autism Spectrum Disorder (ASD), and those with sensory processing dysfunction (SPD) in the absence of an ASD. Performance-based measures of auditory and tactile processing were compared between male children ages 8-12 years assigned to an ASD (N=20), SPD (N=15), or TDC group (N=19). Both the SPD and ASD groups were impaired relative to the TDC group on a performance-based measure of tactile processing (right-handed graphesthesia). In contrast, only the ASD group showed significant impairment on an auditory processing index assessing dichotic listening, temporal patterning, and auditory discrimination. Furthermore, this impaired auditory processing was associated with parent-rated communication skills for both the ASD group and the combined study sample. No significant group differences were detected on measures of left-handed graphesthesia, tactile sensitivity, or form discrimination; however, more participants in the SPD group demonstrated a higher tactile detection threshold (60%) compared to the TDC (26.7%) and ASD groups (35%). This study provides support for use of performance-based measures in the assessment of children with ASD and SPD and highlights the need to better understand how sensory processing affects the higher order cognitive abilities associated with ASD, such as verbal and non-verbal communication, regardless of diagnostic classification.

  16. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study.

    Science.gov (United States)

    Kwon, Hyeok Gyu; Jang, Sung Ho; Lee, Mi Young

    2017-07-01

    Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation) were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1) and secondary somatosensory cortex (S2). In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  17. Recruitment of the middle temporal area by tactile motion in congenital blindness

    DEFF Research Database (Denmark)

    Ptito, Maurice; Matteau, Isabelle; Gjedde, Albert

    2009-01-01

    We used positron emission tomography to investigate whether tactile motion discrimination activates the dorsal visual stream in congenitally blind (CB) participants compared with sighted controls. The tactile stimuli consisted of either static dots, dots moving coherently in one of two possible...... indicate that the dorsal visual pathway is activated by tactile motion stimuli in CB, therefore providing additional support for the cross-modal plasticity hypothesis....

  18. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study

    Directory of Open Access Journals (Sweden)

    Hyeok Gyu Kwon

    2017-01-01

    Full Text Available Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1 and secondary somatosensory cortex (S2. In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  19. The effect of chronic low back pain on tactile suppression during back movements.

    Science.gov (United States)

    Van Damme, Stefaan; Van Hulle, Lore; Danneels, Lieven; Spence, Charles; Crombez, Geert

    2014-10-01

    The aim of the present study was to examine whether tactile suppression, the phenomenon whereby tactile perception is suppressed during movement, would occur in the context of back movements. Of particular interest, it was investigated if tactile suppression in the back would be attenuated in those suffering from chronic low back pain. Individuals with chronic low back pain (N = 30) and a matched control group (N = 24) detected tactile stimuli on three possible locations (back, arm, chest) while performing a back or arm movement, or no movement. We hypothesized that the movements would induce tactile suppression, and that this effect would be largest for low-intense stimuli on the moving body part. We further hypothesized that, during back movements, tactile suppression on the back would be less pronounced in the chronic low back pain group than in the control group. The results showed the expected general tactile suppression effects. The hypothesis of back-specific attenuation of tactile suppression in the chronic low back pain group was not supported. However, back-specific tactile suppression in the chronic low back pain group was less pronounced in those who performed the back movements more slowly. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Tactile roughness perception in the presence of olfactory and trigeminal stimulants

    Directory of Open Access Journals (Sweden)

    Lara A. Koijck

    2015-05-01

    Full Text Available Previous research has shown that odorants consistently evoke associations with textures and their tactile properties like smoothness and roughness. Also, it has been observed that olfaction can modulate tactile perception. We therefore hypothesized that tactile roughness perception may be biased towards the somatosensory connotation of an ambient odorant. We performed two experiments to test this hypothesis. In the first experiment, we investigated the influence of ambient chemosensory stimuli with different roughness connotations on tactile roughness perception. In addition to a pleasant odor with a connotation of softness (PEA, we also included a trigeminal stimulant with a rough, sharp or prickly connotation (Ethanol. We expected that—compared to a No-odorant control condition—tactile texture perception would be biased towards smoothness in the presence of PEA and towards roughness in the presence of Ethanol. However, our results show no significant interaction between chemosensory stimulation and perceived tactile surface roughness. It could be argued that ambient odors may be less effective in stimulating crossmodal associations, since they are by definition extraneous to the tactile stimuli. In an attempt to optimize the conditions for sensory integration, we therefore performed a second experiment in which the olfactory and tactile stimuli were presented in synchrony and in close spatial proximity. In addition, we included pleasant (Lemon and unpleasant (Indole odorants that are known to have the ability to affect tactile perception. We expected that tactile stimuli would be perceived as less rough when simultaneously presented with Lemon or PEA (both associated with softness than when presented with Ethanol or Indole (odors that can be associated with roughness. Again, we found no significant main effect of chemosensory condition on perceived tactile roughness. We discuss the limitations of this study and we present suggestions for

  1. Feasibility study of patient motion monitoring by using tactile array sensors

    Science.gov (United States)

    Kim, Tae-Ho; Kang, Seong-Hee; Kim, Dong-Su; Cho, Min-Seok; Kim, Kyeong-Hyeon; Suh, Tae-Suk; Kim, Siyong

    2015-07-01

    An ideal alignment method based on the external anatomical surface of the patient should consider the entire region of interest. However, optical-camera-based systems cannot blindly monitor such areas as the patient's back, for example. Furthermore, collecting enough information to correct the associated deformation error is impossible. The study aim is to propose a new patient alignment method using tactile array sensors that can measure the distributed pressure profiles along the contact surface. The TactArray system includes one sensor, a signal-conditioning device (USB drive/interface electronics, power supply, and cables), and a PC. The tactile array sensor was placed between the patient's back and the treatment couch, and the deformations at different location on the patient's back were evaluated. Three healthy male volunteers were enrolled in this study, and pressure profile distributions (PPDs) were obtained with and without immobilization. After the initial pretreatment setup using the laser alignment system, the PPD of the patient's back was acquired. The results were obtained at four different times and included a reference PPD dataset. The contact area and the center-of-pressure value were also acquired based on the PPD data for a more elaborate quantitative data analysis. To evaluate the clinical feasibility of using the proposed alignment method for reducing the deformation error, we implemented a real-time self-correction procedure. Despite the initial alignment, we confirmed that PPD variations existed in both cases of the volunteer studies (with and without the use of the immobilization tool). Additionally, we confirmed that the contact area and the center of pressure varied in both cases, and those variations were observed in all three volunteers. With the proposed alignment method and the real-time selfcorrection procedure, the deformation error was significantly reduced. The proposed alignment method can be used to account for the limitation of

  2. Robot Physical Interaction through the combination of Vision, Tactile and Force Feedback Applications to Assistive Robotics

    CERN Document Server

    Prats, Mario; Sanz, Pedro J

    2013-01-01

    Robot manipulation is a great challenge; it encompasses versatility -adaptation to different situations-, autonomy -independent robot operation-, and dependability -for success under modeling or sensing errors. A complete manipulation task involves, first, a suitable grasp or contact configuration, and the subsequent motion required by the task. This monograph presents a unified framework by introducing task-related aspects into the knowledge-based grasp concept, leading to task-oriented grasps. Similarly, grasp-related issues are also considered during the execution of a task, leading to grasp-oriented tasks which is called framework for physical interaction (FPI). The book presents the theoretical framework for the versatile specification of physical interaction tasks, as well as the problem of autonomous planning of these tasks. A further focus is on sensor-based dependable execution combining three different types of sensors: force, vision and tactile. The FPI approach allows to perform a wide range of ro...

  3. The neural substrate for working memory of tactile surface texture.

    Science.gov (United States)

    Kaas, Amanda L; van Mier, Hanneke; Visser, Maya; Goebel, Rainer

    2013-05-01

    Fine surface texture is best discriminated by touch, in contrast to macro geometric features like shape. We used functional magnetic resonance imaging and a delayed match-to-sample task to investigate the neural substrate for working memory of tactile surface texture. Blindfolded right-handed males encoded the texture or location of up to four sandpaper stimuli using the dominant or non-dominant hand. They maintained the information for 10-12 s and then answered whether a probe stimulus matched the memory array. Analyses of variance with the factors Hand, Task, and Load were performed on the estimated percent signal change for the encoding and delay phase. During encoding, contralateral effects of Hand were found in sensorimotor regions, whereas Load effects were observed in bilateral postcentral sulcus (BA2), secondary somatosensory cortex (S2), pre-SMA, dorsolateral prefrontal cortex (dlPFC), and superior parietal lobule (SPL). During encoding and delay, Task effects (texture > location) were found in central sulcus, S2, pre-SMA, dlPFC, and SPL. The Task and Load effects found in hand- and modality-specific regions BA2 and S2 indicate involvement of these regions in the tactile encoding and maintenance of fine surface textures. Similar effects in hand- and modality-unspecific areas dlPFC, pre-SMA and SPL suggest that these regions contribute to the cognitive monitoring required to encode and maintain multiple items. Our findings stress both the particular importance of S2 for the encoding and maintenance of tactile surface texture, as well as the supramodal nature of parieto-frontal networks involved in cognitive control. Copyright © 2012 Wiley Periodicals, Inc.

  4. Kinesthetic information facilitates saccades towards proprioceptive-tactile targets.

    Science.gov (United States)

    Voudouris, Dimitris; Goettker, Alexander; Mueller, Stefanie; Fiehler, Katja

    2016-05-01

    Saccades to somatosensory targets have longer latencies and are less accurate and precise than saccades to visual targets. Here we examined how different somatosensory information influences the planning and control of saccadic eye movements. Participants fixated a central cross and initiated a saccade as fast as possible in response to a tactile stimulus that was presented to either the index or the middle fingertip of their unseen left hand. In a static condition, the hand remained at a target location for the entire block of trials and the stimulus was presented at a fixed time after an auditory tone. Therefore, the target location was derived only from proprioceptive and tactile information. In a moving condition, the hand was first actively moved to the same target location and the stimulus was then presented immediately. Thus, in the moving condition additional kinesthetic information about the target location was available. We found shorter saccade latencies in the moving compared to the static condition, but no differences in accuracy or precision of saccadic endpoints. In a second experiment, we introduced variable delays after the auditory tone (static condition) or after the end of the hand movement (moving condition) in order to reduce the predictability of the moment of the stimulation and to allow more time to process the kinesthetic information. Again, we found shorter latencies in the moving compared to the static condition but no improvement in saccade accuracy or precision. In a third experiment, we showed that the shorter saccade latencies in the moving condition cannot be explained by the temporal proximity between the relevant event (auditory tone or end of hand movement) and the moment of the stimulation. Our findings suggest that kinesthetic information facilitates planning, but not control, of saccadic eye movements to proprioceptive-tactile targets. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Tactile allodynia in patients with lumbar radicular pain (sciatica).

    Science.gov (United States)

    Defrin, Ruth; Devor, Marshall; Brill, Silviu

    2014-12-01

    We report a novel symptom in many patients with low back pain (LBP) that sheds new light on the underlying pain mechanism. By means of quantitative sensory testing, we compared patients with radicular LBP (sciatica), axial LBP (LBP without radiation into the leg), and healthy controls, searching for cutaneous allodynia in response to weak tactile and cooling stimuli on the leg and low back. Most patients with radicular pain (~60%) reported static and dynamic tactile allodynia, as well as cooling allodynia, on the leg, often extending into the foot. Some also reported allodynia on the low back. In axial LBP, allodynia was almost exclusively on the back. The degree of dynamic tactile allodynia correlated with the degree of background pain. The presence of allodynia suggests that the peripheral nerve generators of background leg and back pain have also induced central sensitization. The distal (foot) location of the allodynia in patients who have it indicates that the nociceptive drive that maintains the central sensitization arises paraspinally (ectopically) in injured ventral ramus afferents; this is not an instance of somatic referred pain. The presence of central sensitization also provides the first cogent account of shooting pain in sciatica as a wave of activity sweeping vectorially across the width of the sensitized dorsal horn. Finally, the results endorse leg allodynia as a pain biomarker in animal research on LBP, which is commonly used but has not been previously validated. In addition to informing the underlying mechanism of LBP, bedside mapping of allodynia might have practical implications for prognosis and treatment. How can you tell whether pain radiating into the leg in a patient with sciatica is neuropathic, ie, due to nerve injury? Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  6. A Best-Evidence Synthesis of Research on Orientation and Mobility Involving Tactile Maps and Models

    Science.gov (United States)

    Wright, Tessa; Harris, Beth; Sticken, Eric

    2010-01-01

    A review of the literature from 1965 to 2008 on tactile maps and models in orientation and mobility yielded four pre-experimental and three experimental articles. The articles were analyzed via best-evidence synthesis--a combined narrative and statistical approach--allowing for recommendations for the most effective use of tactile maps and models.…

  7. Vestibulo-tactile interactions regarding motion perception and eye movements in yaw

    NARCIS (Netherlands)

    Bos, J.E.; Erp, J.B.F. van; Groen, E.L.; Veen, H.J. van

    2005-01-01

    This paper shows that tactile stimulation can override vestibular information regarding spinning sensations and eye movements. However, we conclude that the current data do not support the hypothesis that tactile stimulation controls eye movements directly. To this end, twenty-four subjects were

  8. appraisal of the efficacy of tactile subjective test for anaesthesia of ...

    African Journals Online (AJOL)

    Dr Olaleye

    Tactile, verbal subjective, and objective tests were done on 300 patients after inferior dental, lingual, and buccal nerve anaesthetic block injections were given. Of the 78 patients who indicated that there was a change in the middle-third of the lower lip during tactile subjective test, 12 (15.4%) had pain while 66 (84.6%) had ...

  9. Application of tactile displays in sports : where to, how and when to move

    NARCIS (Netherlands)

    Erp, J.B.F. van; Saturday, I.; Jansen, C.

    2006-01-01

    In this paper we explore the possibilities of tactile displays in sports applications, and report an experiment that shows that a tactile feedback systems improves rowing efficiency compared to traditional feedback systems. Earlier papers have shown that localized vibrations provide intuitive cues

  10. Presentation of Various Tactile Sensations Using Micro-Needle Electrotactile Display.

    Directory of Open Access Journals (Sweden)

    Mayuko Tezuka

    Full Text Available Tactile displays provoke tactile sensations by artificially stimulating tactile receptors. While many types of tactile displays have been developed, electrotactile displays that exploit electric stimulation can be designed to be thin, light, flexible and thus, wearable. However, the high voltages required to stimulate tactile receptors and limited varieties of possible sensations pose problems. In our previous work, we developed an electrotactile display using a micro-needle electrode array that can drastically reduce the required voltage by penetrating through the high-impedance stratum corneum painlessly, but displaying various tactile sensations was still a challenge. In this work, we demonstrate presentation of tactile sensation of different roughness to the subjects, which is enabled by the arrangement of the electrodes; the needle electrodes are on the fingertip and the ground electrode is on the fingernail. With this arrangement, the display can stimulate the tactile receptors that are located not only in the shallow regions of the finger but also those in the deep regions. It was experimentally revealed that the required voltage was further reduced compared to previous devices and that the roughness presented by the display was controlled by the pulse frequency and the switching time, or the stimulation flow rate. The proposed electrotactile display is readily applicable as a new wearable haptic device for advanced information communication technology.

  11. Evidence for embodied predictive coding: the anterior insula coordinates cortical processing of tactile deviancy

    DEFF Research Database (Denmark)

    Allen, Micah; Fardo, Francesca; Dietz, Martin

    2015-01-01

    this possibility in the somatosensory domain, we measured brain activity using functional magnetic resonance imaging while healthy participants discriminated tactile stimuli in a roving oddball design. Dynamic Causal Modelling revealed that unexpected stimuli increased the strength of forward connections...... processing of tactile changes to support body awareness....

  12. Audio-tactile stimulation: A tool to improve health and well-being?

    NARCIS (Netherlands)

    Dijk, E.O.; Nijholt, A.; Erp, J.B.F. van; Wolferen, G. van; Kuyper, E.

    2013-01-01

    Stimulation of the tactile sense or the hearing sense can be used to improve a person's health and well-being. For example, to make someone relax, feel better or sleep better. In this position paper, we present the concept of auditory-tactile stimulation for health and well-being. Through carefully

  13. Beats, Flesh, and Grain : Sonic Tactility and Affect in Electronic Dance Music

    NARCIS (Netherlands)

    Garcia, Luis-Manuel

    2015-01-01

    This essay sets out to explore the tactilization of sound in electronic dance music (EDM), which offers an important sensory-affective bridge between touch, sonic experience, and an expansive sense of connection in dancing crowds. EDM events tend to engender spaces of heightened tactility and

  14. Sensory Responsiveness and the Effects of Equal Subjective Rewards on Tactile Learning and Memory of Honeybees

    Science.gov (United States)

    Scheiner, Ricarda; Kuritz-Kaiser, Anthea; Menzel, Randolf; Erber, Joachim

    2005-01-01

    In tactile learning, sucrose is the unconditioned stimulus and reward, which is usually applied to the antenna to elicit proboscis extension and which the bee can drink when it is subsequently applied to the extended proboscis. The conditioned stimulus is a tactile object that the bee can scan with its antennae. In this paper we describe the…

  15. Participation of Parents in the Early Exploration of Tactile Graphics by Children Who Are Visually Impaired

    Science.gov (United States)

    Ryles, Ruby; Bell, Edward

    2009-01-01

    Seventy-three children with visual impairments aged 2-10 and their parents participated in a project that examined the children's interest in and exploration of tactile graphics. The parents reported that the children's interest in and conceptual understanding of the project's tactile workbook were high and that the children explored the…

  16. Weber's Illusion and Body Shape: Anisotropy of Tactile Size Perception on the Hand

    Science.gov (United States)

    Longo, Matthew R.; Haggard, Patrick

    2011-01-01

    The perceived distance between touches on a single skin surface is larger on regions of high tactile sensitivity than those with lower acuity, an effect known as "Weber's illusion". This illusion suggests that tactile size perception involves a representation of the perceived size of body parts preserving characteristics of the somatosensory…

  17. Tactile acuity is disrupted in osteoarthritis but is unrelated to disruptions in motor imagery performance.

    NARCIS (Netherlands)

    Stanton, T.R.; Lin, C.W.; Bray, H.; Smeets, R.J.P.; Taylor, D.; Law, R.Y.; Moseley, G.L.

    2013-01-01

    OBJECTIVE: To determine whether tactile acuity is disrupted in people with knee OA and to determine whether tactile acuity, a clinical signature of primary sensory cortex representation, is related to motor imagery performance (MIP; evaluates working body schema) and pain. METHODS: Experiment 1:

  18. How Do Batters Use Visual, Auditory, and Tactile Information about the Success of a Baseball Swing?

    Science.gov (United States)

    Gray, Rob

    2009-01-01

    Bat/ball contact produces visual (the ball leaving the bat), auditory (the "crack" of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation…

  19. Perceived duration of visual and tactile stimuli depends on perceived speed

    Directory of Open Access Journals (Sweden)

    Alice eTomassini

    2011-09-01

    Full Text Available It is known that the perceived duration of visual stimuli is strongly influenced by speed: faster moving stimuli appear to last longer. To test whether this is a general property of sensory systems we asked participants to reproduce the duration of visual and tactile gratings, and visuo-tactile gratings moving at a variable speed (3.5 – 15 cm/s for three different durations (400, 600 and 800 ms. For both modalities, the apparent duration of the stimulus increased strongly with stimulus speed, more so for tactile than for visual stimuli. In addition, visual stimuli were perceived to last approximately 200 ms longer than tactile stimuli. The apparent duration of visuo-tactile stimuli lay between the unimodal estimates, as the Bayesian account predicts, but the bimodal precision of the reproduction did not show the theoretical improvement. A cross-modal speed-matching task revealed that visual stimuli were perceived to move faster than tactile stimuli. To test whether the large difference in the perceived duration of visual and tactile stimuli resulted from the difference in their perceived speed, we repeated the time reproduction task with visual and tactile stimuli matched in apparent speed. This reduced, but did not completely eliminate the difference in apparent duration. These results show that for both vision and touch, perceived duration depends on speed, pointing to common strategies of time perception.

  20. Tactile Sensing From Laser-Ablated Metallized PET Films

    KAUST Repository

    Nag, Anindya

    2016-10-17

    This paper reports the design, fabrication, and implementation of a novel sensor patch developed from commercial polyethylene terephthalate films metallized with aluminum on one side. The aluminum was ablated with laser to form interdigitated electrodes to make sensor prototypes. The interdigitated electrodes were patterned on the substrate with a laser cutter. Characterization of the prototypes was done to determine their operating frequency followed by experimentation. The prototypes have been used as a tactile sensor showing promising results for using these patches in applications with contact pressures considerably lesser than normal human contact pressure.

  1. Cassini Scientist for a Day: a tactile experience

    Science.gov (United States)

    Canas, L.; Altobelli, N.

    2012-09-01

    In September 2011, the Cassini spacecraft took images of three targets and a challenge was launched to all students: to choose the one target they thought would provide the best science and to write an essay explaining their reasons (more information on the "Cassini Scientist for a Day" essay contest official webpage in: http://saturn.jpl.nasa.gov/education/scientistforaday10thedition/, run by NASA/JPL) The three targets presented were: Hyperion, Rhea and Titan, and Saturn. The idea behind "Cassini Scientist for a Day: a tactile experience" was to transform each of these images into schematic tactile images, highlighting relevant features apprehended through a tactile key, accompanied by a small text in Braille with some additional information. This initial approach would allow reach a broader community of students, more specifically those with visual impairment disabilities. Through proper implementation and careful study cases the adapted images associated with an explanatory key provide more resources in tactile astronomy. As the 2012 edition approaches a new set of targeted objet images will be once again transformed and adapted to visually impaired students and will aim to reach more students into participate in this international competition and to engage them in a quest to expand their knowledge in the amazing Cassini discoveries and the wonders of Saturn and its moons. As the winning essays will be published on the Cassini website and contest winners invited to participate in a dedicated teleconference with Cassini scientists from NASA's Jet Propulsion Laboratory, this initiative presents a great chance to all visually impaired students and teachers to participate in an exciting experience. These initiatives must be complemented with further information to strengthen the learning experience. However they stand as a good starting point to tackle further astronomical concepts in the classroom, especially this field that sometimes lacks the resources. Although

  2. Development and Analysis of New 3D Tactile Materials for the Enhancement of STEM Education for the Blind and Visually Impaired

    Science.gov (United States)

    Gonzales, Ashleigh

    Blind and visually impaired individuals have historically demonstrated a low participation in the fields of science, engineering, mathematics, and technology (STEM). This low participation is reflected in both their education and career choices. Despite the establishment of the Americans with Disabilities Act (ADA) and the Individuals with Disabilities Education Act (IDEA), blind and visually impaired (BVI) students continue to academically fall below the level of their sighted peers in the areas of science and math. Although this deficit is created by many factors, this study focuses on the lack of adequate accessible image based materials. Traditional methods for creating accessible image materials for the vision impaired have included detailed verbal descriptions accompanying an image or conversion into a simplified tactile graphic. It is very common that no substitute materials will be provided to students within STEM courses because they are image rich disciplines and often include a large number images, diagrams and charts. Additionally, images that are translated into text or simplified into basic line drawings are frequently inadequate because they rely on the interpretations of resource personnel who do not have expertise in STEM. Within this study, a method to create a new type of tactile 3D image was developed using High Density Polyethylene (HDPE) and Computer Numeric Control (CNC) milling. These tactile image boards preserve high levels of detail when compared to the original print image. To determine the discernibility and effectiveness of tactile images, these customizable boards were tested in various university classrooms as well as in participation studies which included BVI and sighted students. Results from these studies indicate that tactile images are discernable and were found to improve performance in lab exercises as much as 60% for those with visual impairment. Incorporating tactile HDPE 3D images into a classroom setting was shown to

  3. The Effect of Tactile Cues on Auditory Stream Segregation Ability of Musicians and Nonmusicians

    DEFF Research Database (Denmark)

    Slater, Kyle D.; Marozeau, Jeremy

    2016-01-01

    , we test whether tactile cues can be used to segregate 2 interleaved melodies. Twelve musicians and 12 nonmusicians were asked to detect changes in a 4-note repeated melody interleaved with a random melody. In order to perform this task, the listener must be able to segregate the target melody from...... the random melody. Tactile cues were applied to the listener’s fingers on half of the blocks. Results showed that tactile cues can significantly improve the melodic segregation ability in both musician and nonmusician groups in challenging listening conditions. Overall, the musician group performance...... was always better; however, the magnitude of improvement with the introduction of tactile cues was similar in both groups. This study suggests that hearing-impaired listeners could potentially benefit from a system transmitting such information via a tactile modality...

  4. Independent Attention Mechanisms Control the Activation of Tactile and Visual Working Memory Representations.

    Science.gov (United States)

    Katus, Tobias; Eimer, Martin

    2018-05-01

    Working memory (WM) is limited in capacity, but it is controversial whether these capacity limitations are domain-general or are generated independently within separate modality-specific memory systems. These alternative accounts were tested in bimodal visual/tactile WM tasks. In Experiment 1, participants memorized the locations of simultaneously presented task-relevant visual and tactile stimuli. Visual and tactile WM load was manipulated independently (one, two, or three items per modality), and one modality was unpredictably tested after each trial. To track the activation of visual and tactile WM representations during the retention interval, the visual contralateral delay activity (CDA) and tactile CDA (tCDA) were measured over visual and somatosensory cortex, respectively. CDA and tCDA amplitudes were selectively affected by WM load in the corresponding (tactile or visual) modality. The CDA parametrically increased when visual load increased from one to two and to three items. The tCDA was enhanced when tactile load increased from one to two items and showed no further enhancement for three tactile items. Critically, these load effects were strictly modality-specific, as substantiated by Bayesian statistics. Increasing tactile load did not affect the visual CDA, and increasing visual load did not modulate the tCDA. Task performance at memory test was also unaffected by WM load in the other (untested) modality. This was confirmed in a second behavioral experiment where tactile and visual loads were either two or four items, unimodal baseline conditions were included, and participants performed a color change detection task in the visual modality. These results show that WM capacity is not limited by a domain-general mechanism that operates across sensory modalities. They suggest instead that WM storage is mediated by distributed modality-specific control mechanisms that are activated independently and in parallel during multisensory WM.

  5. Tactile communication, cooperation, and performance: an ethological study of the NBA.

    Science.gov (United States)

    Kraus, Michael W; Huang, Cassey; Keltner, Dacher

    2010-10-01

    Tactile communication, or physical touch, promotes cooperation between people, communicates distinct emotions, soothes in times of stress, and is used to make inferences of warmth and trust. Based on this conceptual analysis, we predicted that in group competition, physical touch would predict increases in both individual and group performance. In an ethological study, we coded the touch behavior of players from the National Basketball Association (NBA) during the 2008-2009 regular season. Consistent with hypotheses, early season touch predicted greater performance for individuals as well as teams later in the season. Additional analyses confirmed that touch predicted improved performance even after accounting for player status, preseason expectations, and early season performance. Moreover, coded cooperative behaviors between teammates explained the association between touch and team performance. Discussion focused on the contributions touch makes to cooperative groups and the potential implications for other group settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  6. [Affective behavioural responses by dogs to tactile human-dog interactions].

    Science.gov (United States)

    Kuhne, Franziska; Hössler, Johanna C; Struwe, Rainer

    2012-01-01

    The communication of dogs is based on complex, subtle body postures and facial expressions. Some social interaction between dogs includes physical contact. Humans generally use both verbal and tactile signals to communicate with dogs. Hence, interaction between humans and dogs might lead to conflicts because the behavioural responses of dogs to human-dog interaction may be misinterpreted and wrongly assessed. The behavioural responses of dogs to tactile human-dog interactions and human gestures are the focus of this study. The participating dogs (n = 47) were privately owned pets.They were of varying breed and gender.The test consisted of nine randomised test sequences (e. g. petting the dog's head or chest). A test sequence was performed for a period of 30 seconds. The inter-trial interval was set at 60 seconds and the test-retest interval was set at 10 minutes. The frequency and duration of the dogs'behavioural responses were recorded using INTERACT. To examine the behavioural responses of the dogs, a two-way analysis of variance within the linear mixed models procedure of IBM SPSS Statistics 19 was conducted. A significant influence of the test-sequenc order on the dogs' behaviour could be analysed for appeasement gestures (F8,137 = 2.42; p = 0.018), redirected behaviour (F8,161 = 6.31; p = 0.012) and socio-positive behaviour (F8,148 = 6.28; p = 0.012). The behavioural responses of the dogs, which were considered as displacement activities (F8,109 = 2.5; p = 0.014) differed significantly among the test sequences. The response of the dogs, measured as gestures of appeasement, redirected behaviours, and displacement activities, was most obvious during petting around the head and near the paws.The results of this study conspicuously indicate that dogs respond to tactile human-dog interactions with gestures of appeasement and displacement activities. Redirected behaviours, socio-positive behaviours as well displacement activities are behavioural responses which dogs

  7. Visual Sensory Signals Dominate Tactile Cues during Docked Feeding in Hummingbirds

    Directory of Open Access Journals (Sweden)

    Benjamin Goller

    2017-11-01

    Full Text Available Animals living in and interacting with natural environments must monitor and respond to changing conditions and unpredictable situations. Using information from multiple sensory systems allows them to modify their behavior in response to their dynamic environment but also creates the challenge of integrating different, and potentially contradictory, sources of information for behavior control. Understanding how multiple information streams are integrated to produce flexible and reliable behavior is key to understanding how behavior is controlled in natural settings. Natural settings are rarely still, which challenges animals that require precise body position control, like hummingbirds, which hover while feeding from flowers. Tactile feedback, available only once the hummingbird is docked at the flower, could provide additional information to help maintain its position at the flower. To investigate the role of tactile information for hovering control during feeding, we first asked whether hummingbirds physically interact with a feeder once docked. We quantified physical interactions between docked hummingbirds and a feeder placed in front of a stationary background pattern. Force sensors on the feeder measured a complex time course of loading that reflects the wingbeat frequency and bill movement of feeding hummingbirds, and suggests that they sometimes push against the feeder with their bill. Next, we asked whether the measured tactile interactions were used by feeding hummingbirds to maintain position relative to the feeder. We created two experimental scenarios—one in which the feeder was stationary and the visual background moved and the other where the feeder moved laterally in front of a white background. When the visual background pattern moved, docked hummingbirds pushed significantly harder in the direction of horizontal visual motion. When the feeder moved, and the background was stationary, hummingbirds generated aerodynamic force

  8. Visual Sensory Signals Dominate Tactile Cues during Docked Feeding in Hummingbirds.

    Science.gov (United States)

    Goller, Benjamin; Segre, Paolo S; Middleton, Kevin M; Dickinson, Michael H; Altshuler, Douglas L

    2017-01-01

    Animals living in and interacting with natural environments must monitor and respond to changing conditions and unpredictable situations. Using information from multiple sensory systems allows them to modify their behavior in response to their dynamic environment but also creates the challenge of integrating different, and potentially contradictory, sources of information for behavior control. Understanding how multiple information streams are integrated to produce flexible and reliable behavior is key to understanding how behavior is controlled in natural settings. Natural settings are rarely still, which challenges animals that require precise body position control, like hummingbirds, which hover while feeding from flowers. Tactile feedback, available only once the hummingbird is docked at the flower, could provide additional information to help maintain its position at the flower. To investigate the role of tactile information for hovering control during feeding, we first asked whether hummingbirds physically interact with a feeder once docked. We quantified physical interactions between docked hummingbirds and a feeder placed in front of a stationary background pattern. Force sensors on the feeder measured a complex time course of loading that reflects the wingbeat frequency and bill movement of feeding hummingbirds, and suggests that they sometimes push against the feeder with their bill. Next, we asked whether the measured tactile interactions were used by feeding hummingbirds to maintain position relative to the feeder. We created two experimental scenarios-one in which the feeder was stationary and the visual background moved and the other where the feeder moved laterally in front of a white background. When the visual background pattern moved, docked hummingbirds pushed significantly harder in the direction of horizontal visual motion. When the feeder moved, and the background was stationary, hummingbirds generated aerodynamic force in the opposite

  9. Neuronal activity in somatosensory cortex related to tactile exploration

    Science.gov (United States)

    Fortier-Poisson, Pascal

    2015-01-01

    The very light contact forces (∼0.60 N) applied by the fingertips during tactile exploration reveal a clearly optimized sensorimotor strategy. To investigate the cortical mechanisms involved with this behavior, we recorded 230 neurons in the somatosensory cortex (S1), as two monkeys scanned different surfaces with the fingertips in search of a tactile target without visual feedback. During the exploration, the monkeys, like humans, carefully controlled the finger forces. High-friction surfaces offering greater tangential shear force resistance to the skin were associated with decreased normal contact forces. The activity of one group of neurons was modulated with either the normal or tangential force, with little or no influence from the orthogonal force component. A second group responded to kinetic friction or the ratio of tangential to normal forces rather than responding to a specific parameter, such as force magnitude or direction. A third group of S1 neurons appeared to respond to particular vectors of normal and tangential force on the skin. Although 45 neurons correlated with scanning speed, 32 were also modulated by finger forces, suggesting that forces on the finger should be considered as the primary parameter encoding the skin compliance and that finger speed is a secondary parameter that co-varies with finger forces. Neurons (102) were also tested with different textures, and the activity of 62 of these increased or decreased in relation to the surface friction. PMID:26467519

  10. Using tactile features to help functionally blind individuals denominate banknotes.

    Science.gov (United States)

    Lederman, Susan J; Hamilton, Cheryl

    2002-01-01

    This study, which was conducted for the Bank of Canada, assessed the feasibility of presenting a raised texture feature together with a tactile denomination code on the next Canadian banknote series ($5, $10, $20, $50, and $100). Adding information accessible by hand would permit functionally blind individuals to independently denominate banknotes. In Experiment 1, 20 blindfolded, sighted university students denominated a set of 8 alternate tactile feature designs. Across the 8 design series, the proportion of correct responses never fell below .97; the mean response time per banknote ranged from 11.4 to 13.1 s. In Experiment 2, 27 functionally blind participants denominated 4 of the previous 8 candidate sets of banknotes. The proportion of correct responses never fell below .92; the corresponding mean response time per banknote ranged from 11.7 to 13.0 s. The Bank of Canada selected one of the four raised-texture designs for inclusion on its new banknote series. Other potential applications include designing haptic displays for teleoperation and virtual environment systems.

  11. Design and fabrication of a novel tactile sensory system applicable in artificial palpation.

    Science.gov (United States)

    Afshari, Elnaz; Najarian, Siamak; Simforoosh, Nasser; Hajizade Farkoush, Siamak

    2011-01-01

    Force and position feedback are the two important parameters that are employed in different medical diagnoses and more specifically surgical operations. Furthermore, during different minimally invasive procedures, the ability of touch and force and position feedback are absent. In this regard, artificial palpation is a new technology that is employed to obtain tactile data in situations where physicians/surgeons cannot use their tactile sense. One of the most valuable achievements of artificial palpation are tactile sensory systems that have various applications in the detection of hard objects inside the soft tissue. Considering the present problems and limitations of kidney stone removal laparoscopy, the aim of this research is to design and fabricate a novel tactile sensory system capable of determining the exact location of stones during laparoscopy. This new tactile sensory system consists of four main parts: The sensory part, the mechanical part, the electrical part, and the display part. In this new system, due to the use of both displacement and force sensors, the usage limitations of previous tactile sensory systems are eliminated. The new tactile sensory system is well capable of finding the stone in the laboratory models through physical contact with the model's surface.

  12. Effectiveness of auditory and tactile crossmodal cues in a dual-task visual and auditory scenario.

    Science.gov (United States)

    Hopkins, Kevin; Kass, Steven J; Blalock, Lisa Durrance; Brill, J Christopher

    2017-05-01

    In this study, we examined how spatially informative auditory and tactile cues affected participants' performance on a visual search task while they simultaneously performed a secondary auditory task. Visual search task performance was assessed via reaction time and accuracy. Tactile and auditory cues provided the approximate location of the visual target within the search display. The inclusion of tactile and auditory cues improved performance in comparison to the no-cue baseline conditions. In comparison to the no-cue conditions, both tactile and auditory cues resulted in faster response times in the visual search only (single task) and visual-auditory (dual-task) conditions. However, the effectiveness of auditory and tactile cueing for visual task accuracy was shown to be dependent on task-type condition. Crossmodal cueing remains a viable strategy for improving task performance without increasing attentional load within a singular sensory modality. Practitioner Summary: Crossmodal cueing with dual-task performance has not been widely explored, yet has practical applications. We examined the effects of auditory and tactile crossmodal cues on visual search performance, with and without a secondary auditory task. Tactile cues aided visual search accuracy when also engaged in a secondary auditory task, whereas auditory cues did not.

  13. Spatial Asynchronous Visuo-Tactile Stimuli influence Ownership of Virtual Wings

    DEFF Research Database (Denmark)

    Andreasen, Anastassia; Nilsson, Niels Chr.; Serafin, Stefania

    2018-01-01

    This poster describes a within-subject study of the virtual body ownership (VBO) illusion using anatomically similar but morphologically different body of a virtual bat. Participants experienced visuo-tactile stimulation of their arms while seeing an object touching the wing of the bat. The mapping...... between the real and the virtual touch points varied across three conditions: no spatial deviation between visual and tactile input, 50% deviation, and 70% deviation. The results suggest that the degree of experienced VBO varies across the conditions. The illusion was broken in the absence of visuo-tactile...

  14. Activation of the hippocampal complex during tactile maze solving in congenitally blind subjects

    DEFF Research Database (Denmark)

    Gagnon, Léa; Schneider, Fabien C; Siebner, Hartwig R

    2012-01-01

    imaging (fMRI) in congenitally blind and blindfolded sighted participants while they navigated through a tactile multiple T-maze. Both groups learned the maze task at a similar pace. In blind participants, tactile maze navigation was associated with increased BOLD responses in the right hippocampus...... and parahippocampus, occipital cortex and fusiform gyrus. Blindfolded sighted controls did not show increased BOLD responses in these areas; instead they activated the caudate nucleus and thalamus. Both groups activated the precuneus during tactile maze navigation. We conclude that cross-modal plastic processes allow...

  15. Use of early tactile stimulation in rehabilitation of digital nerve injuries.

    Science.gov (United States)

    Cheng, A S

    2000-01-01

    Digital nerves are the most frequently injured peripheral nerve. To improve the recovery of functional sensibility of digital nerve injuries, a prospective randomized controlled study was conducted to see the effect of using early tactile stimulation in rehabilitation of digital nerve injuries. Two specific tactile stimulators were made and prescribed for patients with digital nerve-injury. Twenty-four participants with 32 digital nerve injuries received the prescribed tactile stimulators (experimental group), and another 25 participants with 33 digital nerve injuries received only routine conventional therapy (control group). A significant difference (p sensibility in digital nerve injuries without combined nerve, tendon, and bone injuries.

  16. Tactile and visual perception of injection moulded plastic parts

    DEFF Research Database (Denmark)

    Jensen, Jacob Tobias; Akbas, Erkan; Madsen, Mads

    in today’s products and are very important competition factors. This is also the case for light switches which have been chosen as the object that this assignment with revolve around to exemplify the different plastic materials in use in our daily lives. In the light switch marked for traditional light...... switches the technology is almost the same for all manufactures and therefore the visual appeal is very important as a competition factor. Traditional light switches have the button made from plastic material. It is this button that is imagined to be examined to find a plastic surface with a good visual...... appeal (aesthetics) and tactile perception (ergonomics). From this the following thesis has been created: What plastic material and surface texture gives the best combination of aesthetics and ergonomics in the use for buttons on light switches? Throughout the report this thesis will be examined...

  17. Tactile Architectural Models as Universal ‘Urban Furniture’

    Science.gov (United States)

    Kłopotowska, Agnieszka

    2017-10-01

    Tactile architectural models and maquettes have been built in the external public spaces of Polish cities since the latter half of the 00s of the 21st century. These objects are designed for the blind, but also other people - tourists, children, and those who arrive in wheelchairs. This collection has got currently more than 70 implements, which places Poland in the group of European leaders. Unfortunately, this “furniture”, is not always “convenient” and safe for all recipients. Studies, which have been conducted together with Maciej Kłopotowski since 2016 across the country, show a number of serious design and executive mistakes or examples of misuse. The purpose of this article is drawing attention to these issues and pointing out ways how they can be avoided. These objects may become completely valuable, universal tool for learning and a great way of studying architecture in an alternative way.

  18. A Touchy Subject: The Tactile Metaphor Of Touch

    Directory of Open Access Journals (Sweden)

    Mirt Komel

    2016-09-01

    Full Text Available The article proposes an interpretation of metaphors and metaphoric discourse through the perspective of touch. The article first deals with metaphors of touch in the history of western philosophy (especially traditional metaphysics from Plato to Hegel in order to produce an operative category of touch that will allow, in the second step, to grasp the tactile quality of the metaphors. If metaphors are usually (rhetorics, politics, literature regarded as a specific form of language able to not only touch the subject matter in the most suitable way but also touch on the target subject (listener/reader, then it is precisely because there is a certain haptic quality involved in language itself, discernible especially in the discourse of those who know how to best exploit metaphors in their endeavours.

  19. Tactile Feedback Display with Spatial and Temporal Resolutions

    Science.gov (United States)

    Vishniakou, Siarhei; Lewis, Brian W.; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

    2013-08-01

    We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications.

  20. Improving tactile sensation in laparoscopic surgery by overcoming size restrictions

    Directory of Open Access Journals (Sweden)

    Wiederer C.

    2015-09-01

    Full Text Available Hepatic tumors appear as stiff inclusions within the surrounding soft, healthy tissue. In open surgery they are searched for by manual palpation with the gloved fingertip. However, to exploit the benefits of MIS it is mandatory to implement a substitution for the human sense of touch. Therefore, a tactile instrument has been developed with the aim of enlarging the sensing area at the tool tip once it enters the abdominal cavity through the trocar. The provision of a large sensitive surface enables the detection of nearly all sizes of tumors and decreases the time needed for the performance of this task. A prototype was manufactured by laser sintering in PA serving as a carrier for an existing flexible silicone sensor. Automated as well as manual subject palpation tests have shown that a prototypical instrument with a laterally opening lid would be a suitable device for tumor detection in laparoscopic liver surgery.

  1. Attention modulates visual-tactile interaction in spatial pattern matching.

    Directory of Open Access Journals (Sweden)

    Florian Göschl

    Full Text Available Factors influencing crossmodal interactions are manifold and operate in a stimulus-driven, bottom-up fashion, as well as via top-down control. Here, we evaluate the interplay of stimulus congruence and attention in a visual-tactile task. To this end, we used a matching paradigm requiring the identification of spatial patterns that were concurrently presented visually on a computer screen and haptically to the fingertips by means of a Braille stimulator. Stimulation in our paradigm was always bimodal with only the allocation of attention being manipulated between conditions. In separate blocks of the experiment, participants were instructed to (a focus on a single modality to detect a specific target pattern, (b pay attention to both modalities to detect a specific target pattern, or (c to explicitly evaluate if the patterns in both modalities were congruent or not. For visual as well as tactile targets, congruent stimulus pairs led to quicker and more accurate detection compared to incongruent stimulation. This congruence facilitation effect was more prominent under divided attention. Incongruent stimulation led to behavioral decrements under divided attention as compared to selectively attending a single sensory channel. Additionally, when participants were asked to evaluate congruence explicitly, congruent stimulation was associated with better performance than incongruent stimulation. Our results extend previous findings from audiovisual studies, showing that stimulus congruence also resulted in behavioral improvements in visuotactile pattern matching. The interplay of stimulus processing and attentional control seems to be organized in a highly flexible fashion, with the integration of signals depending on both bottom-up and top-down factors, rather than occurring in an 'all-or-nothing' manner.

  2. Spatiotemporal integration of tactile information in human somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Zumer Johanna M

    2007-03-01

    Full Text Available Abstract Background Our goal was to examine the spatiotemporal integration of tactile information in the hand representation of human primary somatosensory cortex (anterior parietal somatosensory areas 3b and 1, secondary somatosensory cortex (S2, and the parietal ventral area (PV, using high-resolution whole-head magnetoencephalography (MEG. To examine representational overlap and adaptation in bilateral somatosensory cortices, we used an oddball paradigm to characterize the representation of the index finger (D2; deviant stimulus as a function of the location of the standard stimulus in both right- and left-handed subjects. Results We found that responses to deviant stimuli presented in the context of standard stimuli with an interstimulus interval (ISI of 0.33s were significantly and bilaterally attenuated compared to deviant stimulation alone in S2/PV, but not in anterior parietal cortex. This attenuation was dependent upon the distance between the deviant and standard stimuli: greater attenuation was found when the standard was immediately adjacent to the deviant (D3 and D2 respectively, with attenuation decreasing for non-adjacent fingers (D4 and opposite D2. We also found that cutaneous mechanical stimulation consistently elicited not only a strong early contralateral cortical response but also a weak ipsilateral response in anterior parietal cortex. This ipsilateral response appeared an average of 10.7 ± 6.1 ms later than the early contralateral response. In addition, no hemispheric differences either in response amplitude, response latencies or oddball responses were found, independent of handedness. Conclusion Our findings are consistent with the large receptive fields and long neuronal recovery cycles that have been described in S2/PV, and suggest that this expression of spatiotemporal integration underlies the complex functions associated with this region. The early ipsilateral response suggests that anterior parietal fields also

  3. Upcoming tactile events and body ownership in schizophrenia.

    Science.gov (United States)

    Ferri, Francesca; Costantini, Marcello; Salone, Anatolia; Di Iorio, Giuseppe; Martinotti, Giovanni; Chiarelli, Antonio; Merla, Arcangelo; Di Giannantonio, Massimo; Gallese, Vittorio

    2014-01-01

    Schizophrenic patients may report unusual perception of their own body. Studies using the rubber hand illusion (RHI) proposed that they exhibit a distorted sense of body ownership. However, since the RHI is mostly achieved with the contribution of visuo-tactile integration, the stronger RHI observed in schizophrenic patients could reflect either a general increase of the response to multisensory stimuli or a larger influence of visual cues on the tactile sensory experience. The purpose of the present study is to investigate patients' perception of their own body by means of a behavioral paradigm that measures their proneness to the RHI without relying on multisensory integration occurring during actual experience of touch. In a previous study we demonstrated in healthy participants that expectation of touch experience arising at the sight of a human hand approaching a rubber hand is enough to induce a sense of ownership over the same hand. Here we take advantage of the same paradigm to investigate body ownership in schizophrenia. Patients observed the experimenter's hand while approaching--without touching--either a rubber hand or a piece of wood placed in front of them. The seen object could be either aligned to participant's hand or rotated by 180°. Phenomenology of the illusion revealed that schizophrenic patients exhibited sense of ownership over the rubber hand, but more weakly than healthy controls. The present study sheds new light on the experience of body ownership in schizophrenic patients, corroborating the notion that alterations of bodily self-awareness play an important role in schizophrenia. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment

    Directory of Open Access Journals (Sweden)

    Jonathan eTong

    2013-09-01

    Full Text Available Two-point discrimination is widely used to measure tactile spatial acuity. The validity of the two-point threshold as a spatial acuity measure rests on the assumption that two points can be distinguished from one only when the two points are sufficiently separated to evoke spatially distinguishable foci of neural activity. However, some previous research has challenged this view, suggesting instead that two-point task performance benefits from an unintended non-spatial cue, allowing spuriously good performance at small tip separations. We compared the traditional two-point task to an equally convenient alternative task in which participants attempt to discern the orientation (vertical or horizontal of two points of contact. We used precision digital readout calipers to administer two-interval forced-choice versions of both tasks to 24 neurologically healthy adults, on the fingertip, finger base, palm, and forearm. We used Bayesian adaptive testing to estimate the participants’ psychometric functions on the two tasks. Traditional two-point performance remained significantly above chance levels even at zero point separation. In contrast, two-point orientation discrimination approached chance as point separation approached zero, as expected for a valid measure of tactile spatial acuity. Traditional two-point performance was so inflated at small point separations that 75%-correct thresholds could be determined on all tested sites for fewer than half of participants. The 95%-correct thresholds on the two tasks were similar, and correlated with receptive field spacing. In keeping with previous critiques, we conclude that the traditional two-point task provides an unintended non-spatial cue, resulting in spuriously good performance at small spatial separations. Unlike two-point discrimination, two-point orientation discrimination rigorously measures tactile spatial acuity. We recommend the use of two-point orientation discrimination for neurological

  5. Ionic Polymer-Metal Composites (IPMCs) as dexterous manipulators and tactile sensors for minimally invasive robotic surgery

    Science.gov (United States)

    Bahramzadeh, Y.; Shahinpoor, M.

    2012-04-01

    Robot-assisted surgery provides the surgeons with new tools to perform sophisticated surgical operations in a minimally invasive manner. Small robotic end-effectors at the tip of the surgical forceps are the key advantage of robotic surgery over laparoscopic surgery and any improvement on the design of these small robots can significantly improve the overall functionality of the surgical robots. In this sense, novel bio-compatible electro-active polymeric actuators can improve the design and functionality of these robotic end-effectors particularly by introducing smaller and more flexible robotic tools. Here, we introduce the applications of IPMCs as flexible actuators with embedded tactile and force feedback sensors in minimally-invasive robotic surgery. A new design for the robotic manipulation of the organs is presented in which a two dimensional IPMC actuator is replaced with the rigid robotic distal tip. It is shown that with a customized design, IPMC actuators maintain the required dexterity for two-dimensional bending of robotic distal tip. The overall design of the robot could be considered as a hybrid robot with the combination of rigid robotic links and flexible IPMC actuator with two degrees of freedom. On the other hand with the current robotic distal tips, no tactile force feedback is available during surgery and the surgeons rely solely on vision feedback. With the proposed design of actuator, the IPMC based distal tip could be used to deliver force feedback data by using an embedded IPMC tactile sensor. Design considerations, kinematics and chemo-electro-mechanical model of the proposed actuator is presented.

  6. Tooteko: a Case Study of Augmented Reality for AN Accessible Cultural Heritage. Digitization, 3d Printing and Sensors for AN Audio-Tactile Experience

    Science.gov (United States)

    D'Agnano, F.; Balletti, C.; Guerra, F.; Vernier, P.

    2015-02-01

    Tooteko is a smart ring that allows to navigate any 3D surface with your finger tips and get in return an audio content that is relevant in relation to the part of the surface you are touching in that moment. Tooteko can be applied to any tactile surface, object or sheet. However, in a more specific domain, it wants to make traditional art venues accessible to the blind, while providing support to the reading of the work for all through the recovery of the tactile dimension in order to facilitate the experience of contact with art that is not only "under glass." The system is made of three elements: a high-tech ring, a tactile surface tagged with NFC sensors, and an app for tablet or smartphone. The ring detects and reads the NFC tags and, thanks to the Tooteko app, communicates in wireless mode with the smart device. During the tactile navigation of the surface, when the finger reaches a hotspot, the ring identifies the NFC tag and activates, through the app, the audio track that is related to that specific hotspot. Thus a relevant audio content relates to each hotspot. The production process of the tactile surfaces involves scanning, digitization of data and 3D printing. The first experiment was modelled on the facade of the church of San Michele in Isola, made by Mauro Codussi in the late fifteenth century, and which marks the beginning of the Renaissance in Venice. Due to the absence of recent documentation on the church, the Correr Museum asked the Laboratorio di Fotogrammetria to provide it with the aim of setting up an exhibition about the order of the Camaldolesi, owners of the San Michele island and church. The Laboratorio has made the survey of the facade through laser scanning and UAV photogrammetry. The point clouds were the starting point for prototypation and 3D printing on different supports. The idea of the integration between a 3D printed tactile surface and sensors was born as a final thesis project at the Postgraduate Mastercourse in Digital

  7. A Dexterity and Tactility Evaluation of the Australian Nuclear Biological Chemical (NBC) Glove

    National Research Council Canada - National Science Library

    Scanlan, S

    2004-01-01

    This report details the tactility and dexterity of four different glove types, including the Australian in-service NBC butyl rubber glove and Nomex flying glove for standardized (Purdue pegboard) and operational...

  8. Tactile search for change has less memory than visual search for change.

    Science.gov (United States)

    Yoshida, Takako; Yamaguchi, Ayumi; Tsutsui, Hideomi; Wake, Tenji

    2015-05-01

    Haptic perception of a 2D image is thought to make heavy demands on working memory. During active exploration, humans need to store the latest local sensory information and integrate it with kinesthetic information from hand and finger locations in order to generate a coherent perception. This tactile integration has not been studied as extensively as visual shape integration. In the current study, we compared working-memory capacity for tactile exploration to that of visual exploration as measured in change-detection tasks. We found smaller memory capacity during tactile exploration (approximately 1 item) compared with visual exploration (2-10 items). These differences generalized to position memory and could not be attributed to insufficient stimulus-exposure durations, acuity differences between modalities, or uncertainty over the position of items. This low capacity for tactile memory suggests that the haptic system is almost amnesic when outside the fingertips and that there is little or no cross-position integration.

  9. Increasing top-down suppression from prefrontal cortex facilitates tactile working memory.

    Science.gov (United States)

    Hannula, Henri; Neuvonen, Tuomas; Savolainen, Petri; Hiltunen, Jaana; Ma, Yuan-Ye; Antila, Hanne; Salonen, Oili; Carlson, Synnöve; Pertovaara, Antti

    2010-01-01

    Navigated transcranial magnetic stimulation (TMS) combined with diffusion-weighted magnetic resonance imaging (DW-MRI) and tractography allows investigating functional anatomy of the human brain with high precision. Here we demonstrate that working memory (WM) processing of tactile temporal information is facilitated by delivering a single TMS pulse to the middle frontal gyrus (MFG) during memory maintenance. Facilitation was obtained only with a TMS pulse applied to a location of the MFG with anatomical connectivity to the primary somatosensory cortex (S1). TMS improved tactile WM also when distractive tactile stimuli interfered with memory maintenance. Moreover, TMS to the same MFG site attenuated somatosensory evoked responses (SEPs). The results suggest that the TMS-induced memory improvement is explained by increased top-down suppression of interfering sensory processing in S1 via the MFG-S1 link. These results demonstrate an anatomical and functional network that is involved in maintenance of tactile temporal WM.

  10. Ventrolateral prefrontal cortex and tactile memory disambiguation in the human brain.

    Science.gov (United States)

    Kostopoulos, Penelope; Albanese, Marie-Claire; Petrides, Michael

    2007-06-12

    Tactile sensory information is first channeled from the primary somatosensory cortex on the postcentral gyrus to the parietal opercular region (i.e., the secondary somatosensory cortex) and the rostral inferior parietal lobule and, from there, to the prefrontal cortex, with which bidirectional connections exist. Although we know that tactile memory signals can be found in the prefrontal cortex, the contribution of the different prefrontal areas to tactile memory remains unclear. The present functional MRI study shows that a specific part of the prefrontal cortex in the human brain, namely the midventrolateral prefrontal region (cytoarchitectonic areas 47/12 and 45), is involved in active controlled retrieval processing necessary for the disambiguation of vibrotactile information in short-term memory. Furthermore, we demonstrate that this particular part of the prefrontal cortex interacts functionally with the secondary somatosensory areas in the parietal operculum and the rostral inferior parietal lobule during controlled processing for the retrieval of specific tactile information.

  11. Microfabrication of Three-Axis Tactile Feedback Actuator for Robot-Assisted Surgery

    Science.gov (United States)

    Doh, Eunhyup; Yoo, Jihyung; Lee, Hyungkew; Park, Joonah; Yun, Kwang-Seok

    2013-01-01

    In this paper, we propose and demonstrate a three-axis tactile feedback actuator using pneumatic balloons for human perception applications such as robot-assisted surgery systems. A tactile actuator is composed of a center structure having four balloons, sidewalls with one lateral balloon on each sidewall, and a bottom structure supporting the center structure. We fabricated the proposed device using flexible poly(dimethylsiloxane) and hard polyurethane with final dimensions of 18 ×18 ×18 mm3. The four balloons on the center structure produce normal tactile display during pneumatic-pressure-assisted inflation. The lateral movement of the center structure driven by sidewall balloons generates a shear tactile display on fingertips. The center deflections of the circular and rectangular balloons were calculated and measured experimentally.

  12. THE BLIND STUDENT AND HIS BODY FEELINGS: WAYS OF BEING AND PERCEIVING THE SCHOOL THROUGH TACTILE MAPS DURING PHYSICAL EDUCATION CLASSES

    Directory of Open Access Journals (Sweden)

    Ruy Antônio Wanderley Rodrigues de Miranda

    2016-03-01

    Full Text Available Historically, physical education in Brazil has been coming through a long process for achieving its position in regular schools. Conquering this place is owed to a large set of debates about the most varied pedagogical concepts.  This study aims at analyzing the body feelings of a blind student and phenomenologically describing this student’s perceptions of school spaces when influenced by the use of tactile maps. The study adopted a qualitative approach from a theoretical-methodological perspective of the case study with phenomenological-existential inspiration.  Based on the dialogues in this study, the authors understood that tactile maps, mediated by the student’s body feelings, represented significant importance to boost memorization of school spaces. This allowed more reliable guidance and safer mobility to that blind student and his own challenges of overcoming physical and attitudinal barriers when he needed to move around daily at school and during physical education classes.

  13. Vagus nerve stimulation paired with tactile training improved sensory function in a chronic stroke patient.

    Science.gov (United States)

    Kilgard, Michael P; Rennaker, Robert L; Alexander, Jen; Dawson, Jesse

    2018-01-01

    Recent studies indicate that vagus nerve stimulation (VNS) paired with rehabilitation can enhance neural plasticity in the primary sensory and motor cortices, improve forelimb function after stroke in animal models and improve motor function in patients with arm weakness after stroke. To gain "first-in-man" experience of VNS paired with tactile training in a patient with severe sensory impairment after stroke. During the long-term follow-up phase of a clinical trial of VNS paired with motor rehabilitation, a 71-year-old man who had made good motor recovery had ongoing severe sensory loss in his left hand and arm. He received VNS paired with tactile therapy in an attempt to improve his sensory function. During twenty 2-hour sessions, each passive and active tactile event was paired with a 0.5 second burst of 0.8 mA VNS. Sensory function was measured before, halfway through, and after this therapy. The patient did not report any side effects during or following VNS+Tactile therapy. Quantitative measures revealed lasting and clinically meaningful improvements in tactile threshold, proprioception, and stereognosis. After VNS+Tactile therapy, the patient was able to detect tactile stimulation to his affected hand that was eight times less intense, identify the joint position of his fingers in the affected hand three times more often, and identify everyday objects using his affected hand seven times more often, compared to baseline. Sensory function significantly improved in this man following VNS paired with tactile stimulation. This approach merits further study in controlled clinical trials.

  14. SOA thresholds for the perception of discrete/continuous tactile stimulation

    DEFF Research Database (Denmark)

    Eid, Mohamad; Korres, Georgios; Jensen, Camilla Birgitte Falk

    In this paper we present an experiment to measure the upper and lower thresholds of the Stimulus Onset Asynchrony (SOA) for continuous/discrete apparent haptic motion. We focus on three stimulation parameters: the burst duration, the SOA time, and the inter-actuator distance (between successive a...... speeds”. The results are discussed in reference to designing a tactile interface for providing continuous haptic motion with a desired speed of continuous tactile stimulation....

  15. Vision affects tactile target and distractor processing even when space is task-irrelevant

    Directory of Open Access Journals (Sweden)

    Ann-Katrin eWesslein

    2014-02-01

    Full Text Available The human brain is adapted to integrate the information from multiple sensory modalities into coherent, robust representations of the objects and events in the external world. A large body of empirical research has demonstrated the ubiquitous nature of the interactions that take place between vision and touch, with the former typically dominating over the latter. Many studies have investigated the influence of visual stimuli on the processing of tactile stimuli (and vice versa. Other studies, meanwhile, have investigated the effect of directing a participant’s gaze either toward or else away from the body-part receiving the target tactile stimulation. Other studies, by contrast, have compared performance in those conditions in which the participant’s eyes have been open versus closed. We start by reviewing the research that has been published to date demonstrating the influence of vision on the processing of tactile targets, that is, on those stimuli that have to be attended or responded to. We outline that many – but not all – of the visuotactile interactions that have been observed to date may be attributable to the direction of spatial attention. We then move on to focus on the crossmodal influence of vision, as well as of the direction of gaze, on the processing of tactile distractors. We highlight the results of those studies demonstrating the influence of vision, rather than gaze direction (i.e., the direction of overt spatial attention, on tactile distractor processing (e.g., tactile variants of the negative-priming or flanker task. The conclusion is that no matter how vision of a tactile distractor is engaged, the result would appear to be the same, namely that tactile distractors are processed more thoroughly.

  16. Glove Type of Wearable Tactile Sensor Produced by Artificial Hollow Fiber

    OpenAIRE

    Hasegawa, Y.; Shikida, M.; Ogura, D.; Sato, K.

    2007-01-01

    We previously proposed an artificial hollow fiber, as a new MEMS material, for thedevelopment of a fabric tactile sensor. The artificial hollow fiber is fabricated by uniformly laminatingmetal and insulation layers onto the surface of an elastic hollow fiber. The fabric tactile sensor is madeby weaving the modified hollow fibers into a cloth. The sensor can detect the contact force bymeasuring changes in capacitance at the points where the warp and weft fibers intersect, and can detect2D cont...

  17. Tactile input and empathy modulate the perception of ambiguous biological motion.

    Science.gov (United States)

    Yiltiz, Hörmetjan; Chen, Lihan

    2015-01-01

    Evidence has shown that task-irrelevant auditory cues can bias perceptual decisions regarding directional information associated with biological motion, as indicated in perceptual tasks using point-light walkers (PLWs) (Brooks et al., 2007). In the current study, we extended the investigation of cross-modal influences to the tactile domain by asking how tactile input resolves perceptual ambiguity in visual apparent motion, and how empathy plays a role in this cross-modal interaction. In Experiment 1, we simulated the tactile feedback on the observers' fingertips when the (upright or inverted) PLWs (comprised of either all red or all green dots) were walking (leftwards or rightwards). The temporal periods between tactile events and critical visual events (the PLW's feet hitting the ground) were manipulated so that the tap could lead, synchronize, or lag the visual foot-hitting-ground event. We found that the temporal structures between tactile (feedback) and visual (hitting) events systematically biases the directional perception for upright PLWs, making either leftwards or rightwards more dominant. However, this effect was absent for inverted PLWs. In Experiment 2, we examined how empathy modulates cross-modal capture. Instead of giving tactile feedback on participants' fingertips, we gave taps on their ankles and presented the PLWs with motion directions of approaching (facing toward observer)/receding (facing away from observer) to resemble normal walking postures. With the same temporal structure, we found that individuals with higher empathy were more subject to perceptual bias in the presence of tactile feedback. Taken together, our findings showed that task-irrelevant tactile input can resolve the otherwise ambiguous perception of the direction of biological motion, and this cross-modal bias was mediated by higher level social-cognitive factors, including empathy.

  18. Tactile input and empathy ability modulate the perception of ambiguous biological motion

    Directory of Open Access Journals (Sweden)

    Hörmetjan eYiltiz

    2015-02-01

    Full Text Available Evidence has shown that task-irrelevant auditory cues can bias perceptual decisions regarding directional information associated with biological motion, as indicated in perceptual tasks using point-light walkers (PLWs (Brooks et al., 2007. In the current study, we extended the investigation of cross-modal influences to the tactile domain by asking how tactile input resolves perceptual ambiguity in visual apparent motion, and how empathy ability plays a role in this cross-modal interaction. In Experiment 1, we simulated the tactile feedback on the observers’ fingertips when the (upright or inverted PLWs (comprised of either all red or all green dots were walking (leftwards or rightwards. The temporal periods between tactile events and critical visual events (the PLW’s feet hitting the ground were manipulated so that the tap could lead, synchronize, or lag with the visual foot-hitting-ground event. We found that the temporal structures between tactile (feedback and visual (hitting events systematically modulate the directional perception for upright PLWs, making either leftwards or rightwards more dominant. However, this temporal modulation effect was absent for inverted PLWs. In Experiment 2, we examined how empathy ability modulates cross-modal capture. Instead of generating tactile feedback on participant’s fingertips, we gave taps on their ankles and presented the PLWs with motion directions of approaching (facing towards observer/receding (facing away from observer to resemble normal walking postures. With the same temporal structure, we found that individuals with higher empathic ability were more subject to perceptual bias in the presence of tactile feedback. Taken together, our findings showed that task-irrelevant tactile input can resolve the otherwise ambiguous perception of the directional information of biological motion, whereas cross-modal modulation was mediated by higher level social-cognitive factors, including empathic

  19. Assessment of Dementia in Individuals with Dual Sensory Loss: Application of a Tactile Test Battery

    Directory of Open Access Journals (Sweden)

    Peter Bruhn

    2018-01-01

    Full Text Available Background/Aims: Individuals with dual sensory loss (DSL are more likely to experience cognitive decline with age than individuals without sensory loss. Other studies have pointed to the challenges in assessing cognitive abilities in individuals with DSL, as most existing instruments rely on use of vision and hearing. The aim of this study was to develop and evaluate a Tactile Test Battery (TTB for cognitive assessment in individuals with DSL. Method: Twenty elderly individuals with DSL, 20 with diagnosed dementia, and 20 without dementia or DSL (controls completed the following tactile tests developed for the present study: Spatial learning, Spatial recall, Tactile form board, Clock reading, and Naming. The participants with dementia and controls also completed the Mini-Mental State Examination (MMSE. Results: Overall, participants with dementia performed significantly worse on the tactile tests than participants with DSL and control participants. No significant differences on the tactile tests were found between participants with DSL and controls. The TTB and MMSE scores correlated significantly. Conclusion: The findings from this study of applying tactile tests for cognitive examination in individuals with DSL are promising. They indicate that symptoms of dementia can be differentiated from symptoms related to DSL.

  20. Tactile learning by a whip spider, Phrynus marginemaculatus C.L. Koch (Arachnida, Amblypygi).

    Science.gov (United States)

    Santer, Roger D; Hebets, Eileen A

    2009-04-01

    The ability of animals to learn and remember underpins many behavioural actions and can be crucial for survival in certain contexts, for example in finding and recognising a habitual refuge. The sensory cues that an animal learns in such situations are to an extent determined by its own sensory specialisations. Whip spiders (Arachnida, Amblypygi) are nocturnal and possess uniquely specialised sensory systems that include elongated 'antenniform' forelegs specialised for use as chemo- and mechanosensory feelers. We tested the tactile learning abilities of the whip spider Phrynus marginemaculatus in a maze learning task with two tactile cues of different texture--one associated with an accessible refuge, and the other with an inaccessible refuge. Over ten training trials, whip spiders got faster and more accurate at finding the accessible refuge. During a subsequent test trial where both refuges were inaccessible, whip spiders searched for significantly longer at the tactile cue previously associated with the accessible refuge. Using high-speed cinematography, we describe three distinct antenniform leg movements used by whip spiders during tactile examination. We discuss the potential importance of tactile learning in whip spider behaviour and a possible role for their unique giant sensory neurons in accessing tactile information.

  1. Complex tactile performance in low visibility: the effect of nitrogen narcosis.

    Science.gov (United States)

    van Wijk, Charles H; Meintjes, Willem A J

    2014-06-01

    In a task-environment where visibility has deteriorated, individuals rely heavily on tactile performance (perception and manipulation) to complete complex tasks. When this happens under hyperbaric conditions, factors like nitrogen narcosis could influence a person's ability to successfully complete such tasks. To examine the effect of nitrogen narcosis on a complex neuropsychological task measuring tactile performance at a pressure of 608 kPa (6 atm abs), in the absence of visual access to the task. In a prospective cross-over study, 139 commercial divers were tested in a dry chamber at 101.3 kPa and 608 kPa. They completed the Tupperware Neuropsychological Task (TNT) of tactile performance without visual access to the task, and completed questionnaires to provide psychological and biographical data, which included trait anxiety and transient mood states, as well as formal qualifications and technical proficiency. A significant decrement (9.5%, P < 0.001) in performance on the TNT at depth was found, irrespective of the sequence of testing. Generally, neither the psychological nor biographical variables showed any significant effect on tactile performance. Tactile performance on the surface was a good indicator of performance at depth. These findings have practical implications for professional diving where conditions of low visibility during deeper diving occur. Recommendations are made towards managing potential impairments in tactile performance, such as pre-dive practical learning ('rehearsal') as an aid to successful completion of tasks.

  2. Retention of high tactile acuity throughout the life span in blindness.

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    Legge, Gordon E; Madison, Cindee; Vaughn, Brenna N; Cheong, Allen M Y; Miller, Joseph C

    2008-11-01

    Previous studies of tactile acuity on the fingertip, using passive touch, have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have reexamined this age dependence with two newly designed tactile-acuity charts that require active exploration of the test symbols. One chart used dot patterns similar to braille, and the other used embossed Landolt rings. Groups of blind braille readers and sighted subjects ranging from 12 to 85 years old were tested in two experiments. We replicated previous findings for sighted subjects by showing an age-related decrease in tactile acuity by nearly 1% per year. Surprisingly, the blind subjects retained high acuity into old age, showing no age-related decline. For the blind subjects, tactile acuity did not correlate with braille reading speed, the amount of daily reading, or the age at which braille was learned. We conclude that when measured with active touch, blind subjects retain high tactile acuity into old age, unlike their aging sighted peers. We propose that blind people's use of active touch in daily activities, not specifically braille reading, results in preservation of tactile acuity across the life span.

  3. Tactile spatial acuity in childhood: effects of age and fingertip size.

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    Ryan M Peters

    Full Text Available Tactile acuity is known to decline with age in adults, possibly as the result of receptor loss, but less is understood about how tactile acuity changes during childhood. Previous research from our laboratory has shown that fingertip size influences tactile spatial acuity in young adults: those with larger fingers tend to have poorer acuity, possibly because mechanoreceptors are more sparsely distributed in larger fingers. We hypothesized that a similar relationship would hold among children. If so, children's tactile spatial acuity might be expected to worsen as their fingertips grow. However, concomitant CNS maturation might result in more efficient perceptual processing, counteracting the effect of fingertip growth on tactile acuity. To investigate, we conducted a cross-sectional study, testing 116 participants ranging in age from 6 to 16 years on a precision-controlled tactile grating orientation task. We measured each participant's grating orientation threshold on the dominant index finger, along with physical properties of the fingertip: surface area, volume, sweat pore spacing, and temperature. We found that, as in adults, children with larger fingertips (at a given age had significantly poorer acuity, yet paradoxically acuity did not worsen significantly with age. We propose that finger growth during development results in a gradual decline in innervation density as receptive fields reposition to cover an expanding skin surface. At the same time, central maturation presumably enhances perceptual processing.

  4. The Effect of Programmable Tactile Displays on Spatial Learning Skills in Children and Adolescents of Different Visual Disability.

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    Leo, Fabrizio; Cocchi, Elena; Brayda, Luca

    2017-07-01

    Vision loss has severe impacts on physical, social and emotional well-being. The education of blind children poses issues as many scholar disciplines (e.g., geometry, mathematics) are normally taught by heavily relying on vision. Touch-based assistive technologies are potential tools to provide graphical contents to blind users, improving learning possibilities and social inclusion. Raised-lines drawings are still the golden standard, but stimuli cannot be reconfigured or adapted and the blind person constantly requires assistance. Although much research concerns technological development, little work concerned the assessment of programmable tactile graphics, in educative and rehabilitative contexts. Here we designed, on programmable tactile displays, tests aimed at assessing spatial memory skills and shapes recognition abilities. Tests involved a group of blind and a group of low vision children and adolescents in a four-week longitudinal schedule. After establishing subject-specific difficulty levels, we observed a significant enhancement of performance across sessions and for both groups. Learning effects were comparable to raised paper control tests: however, our setup required minimal external assistance. Overall, our results demonstrate that programmable maps are an effective way to display graphical contents in educative/rehabilitative contexts. They can be at least as effective as traditional paper tests yet providing superior flexibility and versatility.

  5. Vibro-tactile and auditory balance biofeedback changes muscle activity patterns: Possible implications for vestibular implants.

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    Allum, John H J; Honegger, Flurin

    2017-01-01

    The two different types of balance prostheses being developed, implants and vibro-tactile/auditory feedback prostheses, rely on different measures to prove efficacy (those based on vestibular ocular reflexes versus balance control, respectively). Here we provide evidence that examining muscle activity might provide a useful alternative for both. The muscle activity of 6 bilateral vestibular loss (BVL) and 7 age-matched healthy controls (HC) was examined while standing eyes closed on a foam support surface. Pelvis and upper trunk angular movements were recorded in the roll and pitch planes. Surface EMG was recorded from the lower leg, trunk and upper arm muscles. BVL subjects were first assessed without feedback of pelvis sway, then received training with combined vibro-tactile and auditory feedback, before being re-assessed with feedback. Feedback reduced the amplitudes of pelvis and shoulder sway to values of HC without feedback. Both the level of background EMG activity and the EMG area amplitudes changed when feedback was provided in a manner consistent with the reduced amplitude modulation of muscle synergies of HC. The results of this study indicate that changed muscle synergy amplitudes underlie improvements in sway achieved by BVL subjects. The concept of this investigation may provide a means to prove efficacy for different types of balance prostheses, including implants.

  6. Are We Ready to Build a System for Assisting Blind People in Tactile Exploration of Bas-Reliefs?

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    Francesco Buonamici

    2016-08-01

    Full Text Available Nowadays, the creation of methodologies and tools for facilitating the 3D reproduction of artworks and, contextually, to make their exploration possible and more meaningful for blind users is becoming increasingly relevant in society. Accordingly, the creation of integrated systems including both tactile media (e.g., bas-reliefs and interfaces capable of providing the users with an experience cognitively comparable to the one originally envisioned by the artist, may be considered the next step for enhancing artworks exploration. In light of this, the present work provides a description of a first-attempt system designed to aid blind people (BP in the tactile exploration of bas-reliefs. In detail, consistent hardware layout, comprising a hand-tracking system based on Kinect® sensor and an audio device, together with a number of methodologies, algorithms and information related to physical design are proposed. Moreover, according to experimental test on the developed system related to the device position, some design alternatives are suggested so as to discuss pros and cons.

  7. Development of tactile floor plan for the blind and the visually impaired by 3D printing technique

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    Raša Urbas

    2016-07-01

    Full Text Available The aim of the research was to produce tactile floor plans for blind and visually impaired people for the use in the museum. For the production of tactile floor plans 3D printing technique was selected among three different techniques. 3D prints were made of white and colored ABS polymer materials. Development of different elements of tactile floor plans, as well as the problems and the solutions during 3D printing, are described in the paper.

  8. Robotic and Virtual Reality BCIs Using Spatial Tactile and Auditory Oddball Paradigms.

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    Rutkowski, Tomasz M

    2016-01-01

    The paper reviews nine robotic and virtual reality (VR) brain-computer interface (BCI) projects developed by the author, in collaboration with his graduate students, within the BCI-lab research group during its association with University of Tsukuba, Japan. The nine novel approaches are discussed in applications to direct brain-robot and brain-virtual-reality-agent control interfaces using tactile and auditory BCI technologies. The BCI user intentions are decoded from the brainwaves in realtime using a non-invasive electroencephalography (EEG) and they are translated to a symbiotic robot or virtual reality agent thought-based only control. A communication protocol between the BCI output and the robot or the virtual environment is realized in a symbiotic communication scenario using an user datagram protocol (UDP), which constitutes an internet of things (IoT) control scenario. Results obtained from healthy users reproducing simple brain-robot and brain-virtual-agent control tasks in online experiments support the research goal of a possibility to interact with robotic devices and virtual reality agents using symbiotic thought-based BCI technologies. An offline BCI classification accuracy boosting method, using a previously proposed information geometry derived approach, is also discussed in order to further support the reviewed robotic and virtual reality thought-based control paradigms.

  9. Robotic and Virtual Reality BCIs Using Spatial Tactile and Auditory Oddball Paradigms

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    Tomasz Maciej Rutkowski

    2016-12-01

    Full Text Available The paper reviews nine robotic and virtual reality (VR brain-computer interface (BCI projects developed by the author, in collaboration with his graduate students, within the BCI-lab research group during its association with University of Tsukuba, Japan. The nine novel approaches are discussed in applications to direct brain-robot and brain-virtual-reality-agent control interfaces using tactile and auditory BCI technologies. The BCI user intentions are decoded from the brainwaves in realtime using a non-invasive electroencephalography (EEG and they are translated to a symbiotic robot or virtual reality agent thought-based only control. A communication protocol between the BCI output and the robot or the virtual environment is realized in a symbiotic communication scenario using an user datagram protocol (UDP, which constitutes an internet of things (IoT control scenario. Results obtained from healthy users reproducing simple brain-robot and brain-virtual-agent control tasks in online experiments support the research goal of a possibility to interact with robotic devices and virtual reality agents using symbiotic thought-based BCI technologies. An offline BCI classification accuracy boosting method, using a previously proposed information geometry derived approach, is also discussed in order to further support the reviewed robotic and virtual reality thought-based control paradigms.

  10. Stable phase-shift despite quasi-rhythmic movements: a CPG-driven dynamic model of active tactile exploration in an insect

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    Nalin eHarischandra

    2015-08-01

    Full Text Available An essential component of autonomous and flexible behaviour in animals is active exploration of the environment, allowing for perception-guided planning and control of actions. An important sensory system involved is active touch. Here, we introduce a general modelling framework of Central Pattern Generators (CPGs for movement generation in active tactile exploration behaviour. The CPG consists of two network levels: (i phase-coupled Hopf oscillators for rhythm generation, and (ii pattern formation networks for capturing the frequency and phase characteristics of individual joint oscillations. The model captured the natural, quasi-rhythmic joint kinematics as observed in coordinated antennal movements of walking stick insects. Moreover, it successfully produced tactile exploration behaviour on a three-dimensional skeletal model of the insect antennal system with physically realistic parameters. The effect of proprioceptor ablations could be simulated by changing the amplitude and offset parameters of the joint oscillators, only. As in the animal, the movement of both antennal joints was coupled with a stable phase difference, despite the quasi-rhythmicity of the joint angle time courses. We found that the phase-lead of the distal scape-pedicel joint relative to the proximal head-scape joint was essential for producing the natural tactile exploration behaviour and, thus, for tactile efficiency. For realistic movement patterns, the phase-lead could vary within a limited range of 10 to 30 degrees only. Tests with artificial movement patterns strongly suggest that this phase sensitivity is not a matter of the frequency composition of the natural movement pattern. Based on our modelling results, we propose that a constant phase difference is coded into the CPG of the antennal motor system and that proprioceptors are acting locally to regulate the joint movement amplitude.

  11. State of the Art of Tactile Micro Coordinate Metrology

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    Rudolf Thalmann

    2016-05-01

    Full Text Available Micro parts are increasingly found in a number of industrial products. They often have complex geometrical features in the millimeter to micrometer range which are not accessible or difficult to measure by conventional coordinate measuring machines or by optical microscopy techniques. In the last years, several concepts of tactile micro coordinate measuring machines have been developed in research laboratories and were partly commercialized by industry. The major challenges were related to the development of innovative micro probes, to the requirements for traceability and to the performance assessment at reduced measurement uncertainty. This paper presents a review on state of the art developments of micro coordinate measuring machines and 3D micro probes in the last 20 years, as far as these were qualified in a comparable way, with a special emphasis on research conducted by the Federal Institute of Metrology METAS in this field. It outlines the accuracy limitations for the probe head including the probing element and for the geometrical errors of the machine axes. Finally, the achieved performances are summarized and the challenges for further research are addressed.

  12. Nestmate recognition in ants is possible without tactile interaction

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    Brandstaetter, Andreas Simon; Endler, Annett; Kleineidam, Christoph Johannes

    2008-07-01

    Ants of the genus Camponotus are able to discriminate recognition cues of colony members (nestmates) from recognition cues of workers of a different colony (non-nestmates) from a distance of 1 cm. Free moving, individual Camponotus floridanus workers encountered differently treated dummies on a T-bar and their behavior was recorded. Aggressive behavior was scored as mandibular threat towards dummies. Dummies were treated with hexane extracts of postpharyngeal glands (PPGs) from nestmates or non-nestmates which contain long-chain hydrocarbons in ratios comparable to what is found on the cuticle. The cuticular hydrocarbon profile bears cues which are essential for nestmate recognition. Although workers were prevented from antennating the dummies, they showed significantly less aggressive behavior towards dummies treated with nestmate PPG extracts than towards dummies treated with non-nestmate PPG extracts. In an additional experiment, we show that cis-9-tricosene, an alkene naturally not found in C. floridanus’ cuticular profile, is behaviorally active and can interfere with nestmate recognition when presented together with a nestmate PPG extract. Our study demonstrates for the first time that the complex multi-component recognition cues can be perceived and discriminated by ants at close range. We conclude that contact chemosensilla are not crucial for nestmate recognition since tactile interaction is not necessary.

  13. Microfluidic tactile sensors for three-dimensional contact force measurements.

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    Nie, Baoqing; Li, Ruya; Brandt, James D; Pan, Tingrui

    2014-11-21

    A microfluidic tactile sensing device has been first reported for three-dimensional contact force measurement utilizing the microfluidic interfacial capacitive sensing (MICS) principle. Consisting of common and differential microfluidic sensing elements and topologically micro-textured surfaces, the microfluidic sensing devices are intended not only to resolve normal mechanical loads but also to measure forces tangent to the surface upon contact. In response to normal or shear loads, the membrane surface deforms the underlying sensing elements uniformly or differentially. The corresponding variation in interfacial capacitance can be detected from each sensing unit, from which the direction and magnitude of the original load can be determined. Benefiting from the highly sensitive and adaptive MICS principle, the microfluidic sensor is capable of detecting normal forces with a device sensitivity of 29.8 nF N(-1) in a 7 mm × 7 mm × 0.52 mm package, which is at least a thousand times higher than its solid-state counterparts to our best knowledge. In addition, the microfluidic sensing elements enable facilitated relaxation response/time in the millisecond range (up to 12 ms). To demonstrate the utility and flexibility of the three-dimensional microfluidic sensor, it has been successfully configured into a fingertip-amounted setting for continuous tracing of the fingertip movement and contact force measurement.

  14. Inert gas narcosis has no influence on thermo-tactile sensation.

    Science.gov (United States)

    Jakovljević, Miroljub; Vidmar, Gaj; Mekjavic, Igor B

    2012-05-01

    Contribution of skin thermal sensors under inert gas narcosis to the raising hypothermia is not known. Such information is vital for understanding the impact of narcosis on behavioural thermoregulation, diver safety and judgment of thermal (dis)comfort in the hyperbaric environment. So this study aimed at establishing the effects of normoxic concentration of 30% nitrous oxide (N(2)O) on thermo-tactile threshold sensation by studying 16 subjects [eight females and eight males; eight sensitive (S) and eight non-sensitive (NS) to N(2)O]. Their mean (SD) age was 22.1 (1.8) years, weight 72.8 (15.3) kg, height 1.75 (0.10) m and body mass index 23.8 (3.8) kg m(-2). Quantitative thermo-tactile sensory testing was performed on forearm, upper arm and thigh under two experimental conditions: breathing air (air trial) and breathing normoxic mixture of 30% N(2)O (N(2)O trial) in the mixed sequence. Difference in thermo-tactile sensitivity thresholds between two groups of subjects in two experimental conditions was analysed by 3-way mixed-model analysis of covariance. There were no statistically significant differences in thermo-tactile thresholds either between the Air and N(2)O trials, or between S and NS groups, or between females and males, or with respect to body mass index. Some clinically insignificant lowering of thermo-tactile thresholds occurred only for warm thermo-tactile thresholds on upper arm and thigh. The results indicated that normoxic mixture of 30% N(2)O had no influence on thermo-tactile sensation in normothermia.

  15. Detection of fever in children emergency care: comparisons of tactile and rectal temperatures in Nigerian children

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    Okafor Olubukola O

    2010-04-01

    Full Text Available Abstract Background Clinical thermometry is the objective method for temperature measurements but tactile assessment of fever at home is usually the basis for seeking medical attention especially where the cost and level of literacy preclude the use of thermometers. This study was carried out to determine the reliability of tactile perception of fever by caregivers, nurses and house physicians in comparison to rectal thermometry and also the use of commonly practiced surface of the hand in the care of ill children. All caregivers of children aged 6 to 59 months who presented to the emergency department were approached consecutively at the triage stage but 182 children participated. Each child had tactile assessment of fever using palmar and dorsal surfaces of the hand by the caregivers, House Physicians and Nursing Officers. Rectal temperature was also measured and read independently by nurses and house physicians. Comparisons were made between tactile assessments and thermometer readings using a cut-off for fever, 38.0°C and above. Findings The caregivers' perception of fever had a sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of 95%, 23%, 66% and 73%, respectively compared with 93%, 26%, 67% and 69%, respectively for nursing officers. Irrespective of the groups studied, 77.1% of 336 assessors opined that the dorsal surface of the hand was more sensitive in tactile assessment of temperature and the frequently used site for assessment of fever were the head (35.6% and neck (33.3%. Tactile assessment of temperature over-detected fever in ≥ 24% of cases among the three groups of assessors. Conclusions The present study suggests that tactile assessment of temperature may over estimate the prevalence of fever, it does not detect some cases and the need for objective measurement of temperature is emphasised in paediatric emergency care.

  16. Maintenance of tactile short-term memory for locations is mediated by spatial attention.

    Science.gov (United States)

    Katus, Tobias; Andersen, Søren K; Müller, Matthias M

    2012-01-01

    According to the attention-based rehearsal hypothesis, maintenance of spatial information is mediated by covert orienting towards memorized locations. In a somatosensory memory task, participants simultaneously received bilateral pairs of mechanical sample pulses. For each hand, sample stimuli were randomly assigned to one of three locations (fingers). A subsequent visual retro-cue determined whether the left or right hand sample was to be memorized. The retro-cue elicited lateralized activity reflecting the location of the relevant sample stimulus. Sensory processing during the retention period was probed by task-irrelevant pulses randomized to locations at the cued and uncued hand. The somatosensory N140 was enhanced for probes delivered to the cued hand, relative to uncued. Probes presented shortly after the retro-cue showed greatest attentional modulations. This suggests that transient contributions from retrospective selection overlapped with the sustained effect of attention-based rehearsal. In conclusion, focal attention shifts within tactile mnemonic content occurred after retro-cues and guided sensory processing during retention. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Sensitivity evaluation of the visual, tactile, and auditory detection response task method while driving.

    Science.gov (United States)

    Stojmenova, Kristina; Jakus, Grega; Sodnik, Jaka

    2017-05-19

    In this article, we evaluate the sensitivity to cognitive load of 3 versions of the Detection Response Task method (DRT), proposed in ISO Draft Standard DIS-17488. We present a user study with 30 participants in which we compared the sensitivity to cognitive load of visual, audio, and tactile DRT in a simulated driving environment. The amount of cognitive load was manipulated with secondary n-back tasks at 2 levels of difficulty (0-back and 1-back). We also explored whether the DRT method is least sensitive to cognitive load when the stimuli and secondary task are of the same modality. For this purpose, we used 3 forms to present the n-back task stimuli: visual, audio, and tactile. Responses to the task were always vocal. The experiment was based on a between-subject design (the DRT modalities) with 2 levels of within-subject design study (modalities and difficulty of the secondary n-back tasks). The participants' primary task in the study was to drive safely, and a second priority was to answer to DRT stimuli and perform secondary tasks. The results indicate that all 3 versions of the DRT tested were sensitive to detecting the difference in cognitive load between the reference driving period and driving and engaging in the secondary tasks. Only the visual DRT discriminated between the 0-back and 1-back conditions on mean response time. Contrary to expectations, no interaction was observed between DRT modality and the stimuli modality used for presentation of the secondary tasks. None of the 3 methods of presenting DRT stimuli showed a consistent advantage in sensitivity in differentiating multiple levels of cognitive load if all response times, hit rates, and secondary task performance are considered. If only response time is considered, the visual presentation of the DRT stimulus used in this study showed some advantages. In interpreting these data, it should be noted that the methods of DRT stimulus presentation varied somewhat from the currently proposed draft

  18. Integrated trimodal SSEP experimental setup for visual, auditory and tactile stimulation

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    Kuś, Rafał; Spustek, Tomasz; Zieleniewska, Magdalena; Duszyk, Anna; Rogowski, Piotr; Suffczyński, Piotr

    2017-12-01

    Objective. Steady-state evoked potentials (SSEPs), the brain responses to repetitive stimulation, are commonly used in both clinical practice and scientific research. Particular brain mechanisms underlying SSEPs in different modalities (i.e. visual, auditory and tactile) are very complex and still not completely understood. Each response has distinct resonant frequencies and exhibits a particular brain topography. Moreover, the topography can be frequency-dependent, as in case of auditory potentials. However, to study each modality separately and also to investigate multisensory interactions through multimodal experiments, a proper experimental setup appears to be of critical importance. The aim of this study was to design and evaluate a novel SSEP experimental setup providing a repetitive stimulation in three different modalities (visual, tactile and auditory) with a precise control of stimuli parameters. Results from a pilot study with a stimulation in a particular modality and in two modalities simultaneously prove the feasibility of the device to study SSEP phenomenon. Approach. We developed a setup of three separate stimulators that allows for a precise generation of repetitive stimuli. Besides sequential stimulation in a particular modality, parallel stimulation in up to three different modalities can be delivered. Stimulus in each modality is characterized by a stimulation frequency and a waveform (sine or square wave). We also present a novel methodology for the analysis of SSEPs. Main results. Apart from constructing the experimental setup, we conducted a pilot study with both sequential and simultaneous stimulation paradigms. EEG signals recorded during this study were analyzed with advanced methodology based on spatial filtering and adaptive approximation, followed by statistical evaluation. Significance. We developed a novel experimental setup for performing SSEP experiments. In this sense our study continues the ongoing research in this field. On the

  19. Variation in the autism candidate gene GABRB3 modulates tactile sensitivity in typically developing children

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    Tavassoli Teresa

    2012-07-01

    Full Text Available Abstract Background Autism spectrum conditions have a strong genetic component. Atypical sensory sensitivities are one of the core but neglected features of autism spectrum conditions. GABRB3 is a well-characterised candidate gene for autism spectrum conditions. In mice, heterozygous Gabrb3 deletion is associated with increased tactile sensitivity. However, no study has examined if tactile sensitivity is associated with GABRB3 genetic variation in humans. To test this, we conducted two pilot genetic association studies in the general population, analysing two phenotypic measures of tactile sensitivity (a parent-report and a behavioural measure for association with 43 SNPs in GABRB3. Findings Across both tactile sensitivity measures, three SNPs (rs11636966, rs8023959 and rs2162241 were nominally associated with both phenotypes, providing a measure of internal validation. Parent-report scores were nominally associated with six SNPs (P Conclusions This is the first human study to show an association between GABRB3 variation and tactile sensitivity. This provides support for the evidence from animal models implicating the role of GABRB3 variation in the atypical sensory sensitivity in autism spectrum conditions. Future research is underway to directly test this association in cases of autism spectrum conditions.

  20. Application of artificial tactile sensing approach in kidney-stone-removal laparoscopy.

    Science.gov (United States)

    Afshari, Elnaz; Najarian, Siamak; Simforoosh, Nasser

    2010-01-01

    Artificial tactile sensing is a novel method for obtaining different characteristics of a hard object embedded in a soft tissue. In this regard, artificial palpation is one of the most valuable achievements of artificial tactile sensing that can be used in various fields of medicine and more specifically in surgery. In this study, considering the present problems and limitations in kidney-stone-removal laparoscopy, a new application will be presented for artificial tactile sensing approach. Having imitated surgeon's palpation during open surgery and modeled it conceptually, indications of stone existence that appear on the surface of kidney (due to exerting mechanical load) were determined. A number of different cases were created and solved by the software. Using stress distribution contours and stress graphs, it is illustrated that the created stress patterns on the surface of kidney not only show the existence of stone inside, but also its exact location. In fact, the reliability and accuracy of artificial tactile sensing method in detection of kidney stone during laparoscopy is demonstrated by means of finite element analysis. Also, in this paper, the functional principles of tactile system capable of determining the exact location of stone during laparoscopy will be presented.

  1. VARIATIONS IN TACTILE SIGNING – THE CASE OF ONE-HANDED SIGNING

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    Johanna Mesch

    2011-01-01

    Full Text Available Tactile sign language is a variety of a national sign language. Tactile signing among persons with deafblindness also includes some minor variations. Early analyses of tactile Swedish Sign Language (e.g. Mesch 1998, 2001 show how interactants use both their hands in tactile communication in two different positions: dialogue position and monologue position. This paper examines the signing variations that partially or functionally blind signers encounter when using one hand to communicate with each other in a conversation dyad in what is one of the most advanced types of sign language communication. In tactile one-handed signing, the signer uses her right hand both for producing and receiving signs, while the addressee uses her left hand not only for receiving but also for producing signs after turn-taking, even though it is the non-dominant hand and, therefore, is not normally used to produce one-handed signs. In this study, conversation analysis was conducted on the discourse of four groups. The results show that some variations depend on the linguistic background of individuals and their everyday communication. A comparative study of a two-handed and a one-handed system is then presented, focusing on issues of simplicity, flexibility, turn-taking, and feedback. Some results showing changes in the sign structures of both communication types are also presented.

  2. Tactile graphic: the possible form of information and inclusion of the visually impaired

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    Leia de Andrade

    2011-07-01

    Full Text Available Although the graphics are present in the textbooks, these are not so accessible to the blind. In this case you need to generate them in high relief to be allowed to read through the tactile sense. For research in the development of tactile graphics with students in 5th grade the urban perimeter of Maringá (PR, drew on the Piaget’s theory, who directed the evaluation of the cognitive development of students in the tasks, and also semiology graphics proposed by Bertin, who helped design treatment information for this production. In order to show the importance of tactile graphics for visually impaired students, which are inserted into the regular classroom, it was evaluated the techniques of construction and production of tactile graphic, and the steps of reading material. The results show that the graphs constructed instigate exploration, as much as it was a favor to tactile perception. It is necessary to respect the "living space" of the chart, in the case indicated by the distance between the hands. Regarding reading, the difficulties encountered were the identification of form, the notion of scale and coordinate system.

  3. Peripheral Mechanosensory Neuron Dysfunction Underlies Tactile and Behavioral Deficits in Mouse Models of ASDs.

    Science.gov (United States)

    Orefice, Lauren L; Zimmerman, Amanda L; Chirila, Anda M; Sleboda, Steven J; Head, Joshua P; Ginty, David D

    2016-07-14

    Patients with autism spectrum disorders (ASDs) commonly experience aberrant tactile sensitivity, yet the neural alterations underlying somatosensory dysfunction and the extent to which tactile deficits contribute to ASD characteristics are unknown. We report that mice harboring mutations in Mecp2, Gabrb3, Shank3, and Fmr1 genes associated with ASDs in humans exhibit altered tactile discrimination and hypersensitivity to gentle touch. Deletion of Mecp2 or Gabrb3 in peripheral somatosensory neurons causes mechanosensory dysfunction through loss of GABAA receptor-mediated presynaptic inhibition of inputs to the CNS. Remarkably, tactile defects resulting from Mecp2 or Gabrb3 deletion in somatosensory neurons during development, but not in adulthood, cause social interaction deficits and anxiety-like behavior. Restoring Mecp2 expression exclusively in the somatosensory neurons of Mecp2-null mice rescues tactile sensitivity, anxiety-like behavior, and social interaction deficits, but not lethality, memory, or motor deficits. Thus, mechanosensory processing defects contribute to anxiety-like behavior and social interaction deficits in ASD mouse models. PAPERCLIP. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Investigating interocclusal perception in tactile teeth sensibility using symmetric and asymmetric analysis.

    Science.gov (United States)

    Enkling, Norbert; Nicolay, Claudia; Bayer, Stefan; Mericske-Stern, Regina; Utz, Karl-Heinz

    2010-12-01

    The purpose of this clinical trial was to determine the active tactile sensibility of natural teeth and to obtain a statistical analysis method fitting a psychometric function through the observed data points. On 68 complete dentulous test persons (34 males, 34 females, mean age 45.9 ± 16.1 years), one pair of healthy natural teeth each was tested: n = 24 anterior teeth and n = 44 posterior teeth. The computer-assisted, randomized measurement was done by having the subjects bite on thin copper foils of different thickness (5-200 µm) inserted between the teeth. The threshold of active tactile sensibility was defined by the 50% value of correct answers. Additionally, the gradient of the sensibility curve and the support area (90-10% value) as a description of the shape of the sensibility curve were calculated. For modeling the sensibility curve, symmetric and asymmetric functions were used. The mean sensibility threshold was 14.2 ± 12.1 µm. The older the subject, the higher the tactile threshold (r = 0.42, p = 0.0006). The support area was 41.8 ± 43.3 µm. The higher the 50% threshold, the smaller the gradient of the curve and the larger the support area. The curves showing the active tactile sensibility of natural teeth demonstrate a tendency towards asymmetry, so that the active tactile sensibility of natural teeth can mathematically best be described by using the asymmetric Weibull function.

  5. The TacTip Family: Soft Optical Tactile Sensors with 3D-Printed Biomimetic Morphologies.

    Science.gov (United States)

    Ward-Cherrier, Benjamin; Pestell, Nicholas; Cramphorn, Luke; Winstone, Benjamin; Giannaccini, Maria Elena; Rossiter, Jonathan; Lepora, Nathan F

    2018-04-01

    Tactile sensing is an essential component in human-robot interaction and object manipulation. Soft sensors allow for safe interaction and improved gripping performance. Here we present the TacTip family of sensors: a range of soft optical tactile sensors with various morphologies fabricated through dual-material 3D printing. All of these sensors are inspired by the same biomimetic design principle: transducing deformation of the sensing surface via movement of pins analogous to the function of intermediate ridges within the human fingertip. The performance of the TacTip, TacTip-GR2, TacTip-M2, and TacCylinder sensors is here evaluated and shown to attain submillimeter accuracy on a rolling cylinder task, representing greater than 10-fold super-resolved acuity. A version of the TacTip sensor has also been open-sourced, enabling other laboratories to adopt it as a platform for tactile sensing and manipulation research. These sensors are suitable for real-world applications in tactile perception, exploration, and manipulation, and will enable further research and innovation in the field of soft tactile sensing.

  6. Symbol recognition produced by points of tactile stimulation: the illusion of linear continuity.

    Science.gov (United States)

    Gonzales, G R

    1996-11-01

    To determine whether tactile receptive communication is possible through the use of a mechanical device that produces the phi phenomenon on the body surface. Twenty-six subjects (11 blind and 15 sighted participants) were tested with use of a tactile communication device (TCD) that produces an illusion of linear continuity forming numbers on the dorsal aspect of the wrist. Recognition of a number or number set was the goal. A TCD with protruding and vibrating solenoids produced sequentially delivered points of cutaneous stimulation along a pattern resembling numbers and created the illusion of dragging a vibrating stylet to form numbers, similar to what might be felt by testing for graphesthesia. Blind subjects recognized numbers with fewer trials than did sighted subjects, although all subjects were able to recognize all the numbers produced by the TCD. Subjects who had been blind since birth and had no prior tactile exposure to numbers were able to draw the numbers after experiencing them delivered by the TCD even though they did not recognize their meaning. The phi phenomenon is probably responsible for the illusion of continuous lines in the shape of numbers as produced by the TCD. This tactile illusion could potentially be used for more complex tactile communications such as letters and words.

  7. Tactile force perception depends on the visual speed of the collision object.

    Science.gov (United States)

    Arai, Kan; Okajima, Katsunori

    2009-10-22

    Previous research on the interaction between vision and touch has employed static visual and continuous tactile stimuli, and has shown that two kinds of multimodal interaction effect exist: the averaging effect and the contrast effect. The averaging effect has been used to explain several kinds of stimuli interaction while the contrast effect is associated only with the size-weight illusion (A. Charpentier, 1891). Here, we describe a novel visuotactile interaction using visual motion information that can be explained with the contrast effect. We show that the magnitude of tactile force perception (MTFP) from an impact on the palm is significantly modified by the visual motion information of a virtual collision event. Our collision simulator generates visual stimuli independently from the corresponding tactile stimuli. The results show that visual speed modified MTFP even though the actual contact force remained constant: higher visual pre- and post-collision speeds induced lower tactile force perception. Finally, we propose a quantitative model of MTFP in which MTFP is expressed as a function of the visual velocity difference, suggesting that the gain of the tactile perception in the human brain is altered via MTFP modulation.

  8. Artificial muscle actuators for haptic displays: system design to match the dynamics and tactile sensitivity of the human fingerpad

    Science.gov (United States)

    Biggs, S. James; Hitchcock, Roger N.

    2010-04-01

    Electroactive Polymer Artificial Muscles (EPAMTM) based on dielectric elastomers have the bandwidth and the energy density required to make haptic displays that are both responsive and compact. Recent work at Artificial Muscle Inc. has been directed toward the development of thin, high-fidelity haptic modules for mobile handsets. The modules provide the brief tactile "click" that confirms key press, and the steady state "bass" effects that enhance gaming and music. To design for these capabilities we developed a model of the physical system comprised of the actuator, handset, and user. Output of the physical system was passed through a transfer function to covert vibration into an estimate of the intensity of the user's haptic sensation. A model of fingertip impedance versus button press force is calibrated to data, as is impedance of the palm holding a handset. An energy-based model of actuator performance is derived and calibrated, and the actuator geometry is tuned for good haptic performance.

  9. Prenatal tactile stimulation attenuates drug-induced behavioral sensitization, modifies behavior, and alters brain architecture.

    Science.gov (United States)

    Muhammad, Arif; Kolb, Bryan

    2011-07-11

    Based on the findings of postnatal tactile stimulation (TS), a favorable experience in rats, the present study examined the influence of prenatal TS on juvenile behavior, adult amphetamine (AMPH) sensitization, and structural alteration in the prefrontal cortex (PFC) and the striatum. Female rats received TS through a baby hair brush throughout pregnancy, and the pups born were tested for open field locomotion, elevated plus maze (EPM), novel object recognition (NOR), and play fighting behaviors. Development and persistence of drug-induced behavioral sensitization in adults were tested by repeated AMPH administration and a challenge, respectively. Structural plasticity in the brain was assessed from the prefrontal cortical thickness and striatum size from serial coronal sections. The results indicate that TS females showed enhanced exploration in the open field. TS decreased the frequency of playful attacks whereas the response to face or evade an attack was not affected. Anxiety-like behavior and cognitive performance were not influenced by TS. AMPH administration resulted in gradual increase in locomotor activity (i.e., behavioral sensitization) that persisted at least for 2 weeks. However, both male and female TS rats exhibited attenuated AMPH sensitization compared to sex-matched controls. Furthermore, the drug-associated alteration in the prefrontal cortical thickness and striatum size observed in controls were prevented by TS experience. In summary, TS during prenatal development modified juvenile behavior, attenuated drug-induced behavioral sensitization in adulthood, and reorganized brain regions implicated in drug addiction. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Real-Time Gesture-Controlled Physical Modelling Music Synthesis with Tactile Feedback

    Directory of Open Access Journals (Sweden)

    David M. Howard

    2004-06-01

    Full Text Available Electronic sound synthesis continues to offer huge potential possibilities for the creation of new musical instruments. The traditional approach is, however, seriously limited in that it incorporates only auditory feedback and it will typically make use of a sound synthesis model (e.g., additive, subtractive, wavetable, and sampling that is inherently limited and very often nonintuitive to the musician. In a direct attempt to challenge these issues, this paper describes a system that provides tactile as well as acoustic feedback, with real-time synthesis that invokes a more intuitive response from players since it is based upon mass-spring physical modelling. Virtual instruments are set up via a graphical user interface in terms of the physical properties of basic well-understood sounding objects such as strings, membranes, and solids. These can be interconnected to form complex integrated structures. Acoustic excitation can be applied at any point mass via virtual bowing, plucking, striking, specified waveform, or from any external sound source. Virtual microphones can be placed at any point masses to deliver the acoustic output. These aspects of the instrument are described along with the nature of the resulting acoustic output.

  11. A Meta-Analytic Review of Tactile-Cued Self-Monitoring Interventions Used by Students in Educational Settings

    Science.gov (United States)

    McDougall, Dennis; Ornelles, Cecily; Mersberg, Kawika; Amona, Kekama

    2015-01-01

    In this meta-analytic review, we critically evaluate procedures and outcomes from nine intervention studies in which students used tactile-cued self-monitoring in educational settings. Findings suggest that most tactile-cued self-monitoring interventions have moderate to strong effects, have emerged only recently, and have not yet achieved the…

  12. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

    Directory of Open Access Journals (Sweden)

    Honda Manabu

    2006-12-01

    Full Text Available Abstract Background It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1, is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D shapes on Mah-Jong tiles (Mah-Jong experts. Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. Results When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. Conclusion The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  13. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex.

    Science.gov (United States)

    Saito, Daisuke N; Okada, Tomohisa; Honda, Manabu; Yonekura, Yoshiharu; Sadato, Norihiro

    2006-12-05

    It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1), is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D) shapes on Mah-Jong tiles (Mah-Jong experts). Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO) and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.

  14. Teacher-Made Tactile Science Materials with Critical and Creative Thinking Activities for Learners Including Those with Visual Impairments

    Science.gov (United States)

    Teske, Jolene K.; Gray, Phyllis; Kuhn, Mason A.; Clausen, Courtney K.; Smith, Latisha L.; Alsubia, Sukainah A.; Ghayoorad, Maryam; Rule, Audrey C.; Schneider, Jean Suchsland

    2014-01-01

    Gifted students with visual impairments are twice exceptional learners and may not evidence their advanced science aptitudes without appropriate accommodations for learning science. However, effective tactile science teaching materials may be easily made. Recent research has shown that when tactile materials are used with "all" students…

  15. Finger pad friction and tactile perception of laser treated, stamped and cold rolled micro-structured stainless steel sheet surfaces

    NARCIS (Netherlands)

    Zhang, Sheng; Zeng, X.; Matthews, D.T.A.; Igartua, A.; Rodriguez Vidal, E.; Contreras Fortes, J.; Van Der Heide, E.

    2017-01-01

    Tactile perception is a complex system, which depends on frictional interactions between skin and counter-body. The contact mechanics of tactile friction is governed by many factors such as the state and properties of skin and counter-body. In order to discover the connection between perception and

  16. Finger pad friction and tactile perception of laser treated, stamped and cold rolled micro-structured stainless steel sheet surfaces

    NARCIS (Netherlands)

    Zhang, S.; Zeng, X.; Matthews, D. T A; Igartua, A.; Rodriguez-Vidal, E.; Contreras Fortes, J.; van der Heide, E.

    2017-01-01

    Tactile perception is a complex system, which depends on frictional interactions between skin and counter-body. The contact mechanics of tactile friction is governed by many factors such as the state and properties of skin and counter-body. In order to discover the connection between perception

  17. Evaluation of Circle Diameter by Distributed Tactile Information in Active Tracing

    Directory of Open Access Journals (Sweden)

    Hiroyuki Nakamoto

    2013-01-01

    Full Text Available Active touch with voluntary movement on the surface of an object is important for human to obtain the local and detailed features on it. In addition, the active touch is considered to enhance the human spatial resolution. In order to improve dexterity performance of multifinger robotic hands, it is necessary to study an active touch method for robotic hands. In this paper, first, we define four requirements of a tactile sensor for active touch and design a distributed tactile sensor model, which can measure a distribution of compressive deformation. Second, we suggest a measurement process with the sensor model, a synthesis method of distributed deformations. In the experiments, a five-finger robotic hand with tactile sensors traces on the surface of cylindrical objects and evaluates the diameters. We confirm that the hand can obtain more information of the diameters by tracing the finger.

  18. Combining Electromyography and Tactile Myography to Improve Hand and Wrist Activity Detection in Prostheses

    Directory of Open Access Journals (Sweden)

    Noémie Jaquier

    2017-10-01

    Full Text Available Despite recent advances in prosthetics and assistive robotics in general, robust simultaneous and proportional control of dexterous prosthetic devices remains an unsolved problem, mainly because of inadequate sensorization. In this paper, we study the application of regression to muscle activity, detected using a flexible tactile sensor recording muscle bulging in the forearm (tactile myography—TMG. The sensor is made of 320 highly sensitive cells organized in an array forming a bracelet. We propose the use of Gaussian process regression to improve the prediction of wrist, hand and single-finger activation, using TMG, surface electromyography (sEMG; the traditional approach in the field, and a combination of the two. We prove the effectiveness of the approach for different levels of activations in a real-time goal-reaching experiment using tactile data. Furthermore, we performed a batch comparison between the different forms of sensorization, using a Gaussian process with different kernel distances.

  19. The Tactile Ethics of Soft Robotics: Designing Wisely for Human-Robot Interaction.

    Science.gov (United States)

    Arnold, Thomas; Scheutz, Matthias

    2017-06-01

    Soft robots promise an exciting design trajectory in the field of robotics and human-robot interaction (HRI), promising more adaptive, resilient movement within environments as well as a safer, more sensitive interface for the objects or agents the robot encounters. In particular, tactile HRI is a critical dimension for designers to consider, especially given the onrush of assistive and companion robots into our society. In this article, we propose to surface an important set of ethical challenges for the field of soft robotics to meet. Tactile HRI strongly suggests that soft-bodied robots balance tactile engagement against emotional manipulation, model intimacy on the bonding with a tool not with a person, and deflect users from personally and socially destructive behavior the soft bodies and surfaces could normally entice.

  20. The immediate effects of lidocaine iontophoresis using interferential current on pressure sense threshold and tactile sensation.

    Science.gov (United States)

    Yoosefinejad, Amin Kordi; Motealleh, Alireza; Abbasnia, Keramatollah

    2016-01-01

    Iontophoresis is the noninvasive delivery of ions using direct current. The direct current has some disadvantages such as skin burning. Interferential current is a kind of alternating current without limitations of direct current; so the purpose of this study is to investigate and compare the effects of lidocaine, interferential current and lidocaine iontophoresis using interferential current. 30 healthy women aged 20-24 years participated in this randomized clinical trial study. Pressure, tactile and pain thresholds were evaluated before and after the application of treatment methods. Pressure, tactile and pain sensitivity increased significantly after the application of lidocaine alone (p interferential current (p interferential current can increase perception threshold of pain, tactile stimulus and pressure sense more significantly than lidocaine and interferential current alone.

  1. The influence of tactile cognitive maps on auditory space perception in sighted persons.

    Directory of Open Access Journals (Sweden)

    Alessia Tonelli

    2016-11-01

    Full Text Available We have recently shown that vision is important to improve spatial auditory cognition. In this study we investigate whether touch is as effective as vision to create a cognitive map of a soundscape. In particular we tested whether the creation of a mental representation of a room, obtained through tactile exploration of a 3D model, can influence the perception of a complex auditory task in sighted people. We tested two groups of blindfolded sighted people – one experimental and one control group – in an auditory space bisection task. In the first group the bisection task was performed three times: specifically, the participants explored with their hands the 3D tactile model of the room and were led along the perimeter of the room between the first and the second execution of the space bisection. Then, they were allowed to remove the blindfold for a few minutes and look at the room between the second and third execution of the space bisection. Instead, the control group repeated for two consecutive times the space bisection task without performing any environmental exploration in between. Considering the first execution as a baseline, we found an improvement in the precision after the tactile exploration of the 3D model. Interestingly, no additional gain was obtained when room observation followed the tactile exploration, suggesting that no additional gain was obtained by vision cues after spatial tactile cues were internalized. No improvement was found between the first and the second execution of the space bisection without environmental exploration in the control group, suggesting that the improvement was not due to task learning. Our results show that tactile information modulates the precision of an ongoing space auditory task as well as visual information. This suggests that cognitive maps elicited by touch may participate in cross-modal calibration and supra-modal representations of space that increase implicit knowledge about sound

  2. Short-term visual deprivation does not enhance passive tactile spatial acuity.

    Directory of Open Access Journals (Sweden)

    Michael Wong

    Full Text Available An important unresolved question in sensory neuroscience is whether, and if so with what time course, tactile perception is enhanced by visual deprivation. In three experiments involving 158 normally sighted human participants, we assessed whether tactile spatial acuity improves with short-term visual deprivation over periods ranging from under 10 to over 110 minutes. We used an automated, precisely controlled two-interval forced-choice grating orientation task to assess each participant's ability to discern the orientation of square-wave gratings pressed against the stationary index finger pad of the dominant hand. A two-down one-up staircase (Experiment 1 or a Bayesian adaptive procedure (Experiments 2 and 3 was used to determine the groove width of the grating whose orientation each participant could reliably discriminate. The experiments consistently showed that tactile grating orientation discrimination does not improve with short-term visual deprivation. In fact, we found that tactile performance degraded slightly but significantly upon a brief period of visual deprivation (Experiment 1 and did not improve over periods of up to 110 minutes of deprivation (Experiments 2 and 3. The results additionally showed that grating orientation discrimination tends to improve upon repeated testing, and confirmed that women significantly outperform men on the grating orientation task. We conclude that, contrary to two recent reports but consistent with an earlier literature, passive tactile spatial acuity is not enhanced by short-term visual deprivation. Our findings have important theoretical and practical implications. On the theoretical side, the findings set limits on the time course over which neural mechanisms such as crossmodal plasticity may operate to drive sensory changes; on the practical side, the findings suggest that researchers who compare tactile acuity of blind and sighted participants should not blindfold the sighted participants.

  3. Fiber-optic Sensor of Tactile Force for Anthropomorphic Robot Grips

    Science.gov (United States)

    Matyunin, SA; Babaev, O. G.

    2018-01-01

    This paper examines an operating principle of a Fiber-Optic Tactile Force Sensor (FOTFS), describes a linearization method and temperature compensation on transfer characteristics (TC) of the FOTFS. The high linearity of the FOTFS TC (the nonlinearity of the TC does not exceed 0.01% within the range of tactile forces from 0 to 1.4 N) and the high temperature stability of the FOTFS (the temperature coefficient does not exceed 0.0025%/°C within the temperature range from 0 to + 50 °C) are experimentally-confirmed.

  4. TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

    DEFF Research Database (Denmark)

    Ptito, M; Fumal, A; de Noordhout, A Martens

    2008-01-01

    stimulation (TMS) in early blind subjects and in blindfolded seeing controls. Whereas blindfolded seeing controls reported only phosphenes following occipital cortex stimulation, some of the blind subjects reported tactile sensations in the fingers that were somatotopically organized onto the visual cortex....... The number of cortical sites inducing tactile sensations appeared to be related to the number of hours of Braille reading per day, Braille reading speed and dexterity. These data, taken in conjunction with previous anatomical, behavioural and functional imaging results, suggest the presence of a polysynaptic...

  5. Tactile Reflex Development Through Wing Tsun’s “Sticking Hands” Practice, by Jeff Webb

    Directory of Open Access Journals (Sweden)

    Jeff Webb

    2012-07-01

    Full Text Available It was the late Bruce Lee who first demonstrated Wing Tsun gongfu’s “sticking hands” (chi-sau exercise in the US, during the 1964 Long Beach International Karate Championships. Forty-four years later, very few outside of the art truly understand the purpose of chi-sau let alone how it develops tactile reflexes. This article will describe both the fundamental and complex methods of chi-sau training in detail. It will also explain the rationale and theories behind this method as well as discuss a variety of factors that can either improve or retard the acquisition of tactile reflexes.

  6. Pure associative tactile agnosia for the left hand: clinical and anatomo-functional correlations.

    Science.gov (United States)

    Veronelli, Laura; Ginex, Valeria; Dinacci, Daria; Cappa, Stefano F; Corbo, Massimo

    2014-09-01

    Associative tactile agnosia (TA) is defined as the inability to associate information about object sensory properties derived through tactile modality with previously acquired knowledge about object identity. The impairment is often described after a lesion involving the parietal cortex (Caselli, 1997; Platz, 1996). We report the case of SA, a right-handed 61-year-old man affected by first ever right hemispheric hemorrhagic stroke. The neurological examination was normal, excluding major somaesthetic and motor impairment; a brain magnetic resonance imaging (MRI) confirmed the presence of a right subacute hemorrhagic lesion limited to the post-central and supra-marginal gyri. A comprehensive neuropsychological evaluation detected a selective inability to name objects when handled with the left hand in the absence of other cognitive deficits. A series of experiments were conducted in order to assess each stage of tactile recognition processing using the same stimulus sets: materials, 3D geometrical shapes, real objects and letters. SA and seven matched controls underwent the same experimental tasks during four sessions in consecutive days. Tactile discrimination, recognition, pantomime, drawing after haptic exploration out of vision and tactile-visual matching abilities were assessed. In addition, we looked for the presence of a supra-modal impairment of spatial perception and of specific difficulties in programming exploratory movements during recognition. Tactile discrimination was intact for all the stimuli tested. In contrast, SA was able neither to recognize nor to pantomime real objects manipulated with the left hand out of vision, while he identified them with the right hand without hesitations. Tactile-visual matching was intact. Furthermore, SA was able to grossly reproduce the global shape in drawings but failed to extract details of objects after left-hand manipulation, and he could not identify objects after looking at his own drawings. This case

  7. A Bio-Hybrid Tactile Sensor Incorporating Living Artificial Skin and an Impedance Sensing Array

    Directory of Open Access Journals (Sweden)

    David Cheneler

    2014-12-01

    Full Text Available The development of a bio-hybrid tactile sensor array that incorporates a skin analogue comprised of alginate encapsulated fibroblasts is described. The electrical properties are modulated by mechanical stress induced during contact, and changes are detected by a ten-channel dual-electrode impedance sensing array. By continuously monitoring the impedance of the sensor array at a fixed frequency, whilst normal and tangential loads are applied to the skin surface, transient mechanotransduction has been observed. The results demonstrate the effectiveness and feasibility of the preliminary prototype bio-hybrid tactile sensor.

  8. Sensory prediction on a whiskered robot: A tactile analogy to "optic flow"

    Directory of Open Access Journals (Sweden)

    Christopher L Schroeder

    2012-10-01

    Full Text Available When an animal moves an array of sensors (e.g., the hand, the eye through the environment, spatial and temporal gradients of sensory data are related by the velocity of the moving sensory array. In vision, the relationship between spatial and temporal brightness gradients is quantified in the optical flow equation. In the present work, we suggest an analog to optical flow for the rodent vibrissal (whisker array, in which the perceptual intensity that flows over the array is bending moment. Changes in bending moment are directly related to radial object distance, defined as the distance between the base of a whisker and the point of contact with the object. Using both simulations and a 1x5 array (row of artificial whiskers, we demonstrate that local object curvature can be estimated based on differences in radial distance across the array. We then develop two algorithms, both based on tactile flow, to predict the future contact points that will be obtained as the whisker array translates along the object. The translation of the robotic whisker array represents the rat's head velocity. The first algorithm uses a calculation of the local object slope, while the second uses a calculation of the local object curvature. Both algorithms successfully predict future contact points for simple surfaces. The algorithm based on curvature was found to more accurately predict future contact points as surfaces became more irregular. We quantify the inter-related effects of whisker spacing and the object’s spatial frequencies, and examine the issues that arise in the presence of real-world noise, friction, and slip.

  9. Now you feel both: Galvanic vestibular stimulation induces lasting improvements in the rehabilitation of chronic tactile extinction

    Directory of Open Access Journals (Sweden)

    Lena eSchmidt

    2013-03-01

    Full Text Available Tactile extinction is frequent, debilitating and often persistent after brain damage. Currently, there is no treatment available for this disorder. In two previous case studies we showed an influence of galvanic vestibular stimulation (GVS on tactile extinction. Here, we evaluated in further patients the immediate and lasting effects of GVS on tactile extinction. GVS is known to induce polarity-specific changes in cerebral excitability in the vestibular cortices and adjacent cortical areas. Tactile extinction was examined with the Quality Extinction Test (QET where subjects have to discriminate six different tactile fabrics in bilateral, double simultaneous stimulations (DSS on their dorsum of hands with identical or different tactile fabrics. Twelve patients with stable left-sided tactile extinction after unilateral right-hemisphere lesions were divided into two groups. The GVS group (N=6 performed the QET under six different experimental conditions (two Baselines, Sham-GVS, left-cathodal/right-anodal GVS, right-cathodal/left-anodal GVS, and a follow-up test. The second group of patients with left-sided extinction (N=6 performed the QET six times repetitively, but without receiving GVS (control group. Both right-cathodal/left-anodal as well as left-cathodal/right-anodal GVS (mean: 0.67 mA improved tactile identification of identical and different stimuli in the experimental group. These results show a generic effect of GVS on tactile extinction, but not in a polarity-specific way. These observed effects persisted at Follow-up. Sham-GVS had no significant effect on extinction. In the control group, no significant improvements were seen in the QET after the six measurements of the QET, thus ruling out test repetition effects. In conclusion, GVS improved bodily awareness permanently for the contralesional body side in patients with tactile extinction and thus offers a novel treatment option for these patients.

  10. I Show You How I Like You: Emotional Human-Robot Interaction through Facial Expression and Tactile Stimulation

    DEFF Research Database (Denmark)

    Fredslund, Jakob; Cañamero, Lola D.

    2001-01-01

    We report work on a LEGO robot capable of displaying several emo- tional expressions in response to physical contact. Our motivation has been to explore believable emotional exchanges to achieve plausible interaction with a simple robot. We have worked toward this goal in two ways. First......, emotional states need to be clearly conveyed. We have drawn inspira- tion from theories of human basic emotions with associated universal facial expressions, which we have implemented in a caricaturized face. We have conducted experiments on both children and adults to assess the recogniz- ability......, acknowledging the importance of physical manipulation in children's inter- actions, interaction with the robot is through tactile stimulation; the various kinds of stimulation that can elicit the robot's emotions are grounded in a model of emotion activation based on different stimulation patterns. Sec- ond...

  11. Assessment of cognitive workload of in-vehicle systems using a visual peripheral and tactile detection task setting.

    Science.gov (United States)

    Bengler, Klaus; Kohlmann, Martin; Lange, Christian

    2012-01-01

    The increase of driver information and infotainment systems includes also interaction technologies like speech interaction that minimize visual-manual demand and put the focus to cognitive demand. The question is whether this could lead to distraction effects and decreased traffic safety. This study presents an evaluation method for cognitive demand based on different detection paradigms in a dual task setting. A listening and a backward counting task are realized on three difficulty levels as simulations of cognitively loading secondary tasks and investigated using a visual versus a tactile detection paradigm. The results show that both detection paradigms are able to discriminate the task levels and that subjects successfully apply compensation strategies in the dual task setting especially during the listening task.

  12. Blind Students' Learning of Probability through the Use of a Tactile Model

    Science.gov (United States)

    Vita, Aida Carvalho; Kataoka, Verônica Yumi

    2014-01-01

    The objective of this paper is to discuss how blind students learn basic concepts of probability using the tactile model proposed by Vita (2012). Among the activities were part of the teaching sequence "Jefferson's Random Walk", in which students built a tree diagram (using plastic trays, foam cards, and toys), and pictograms in 3D…

  13. Using Captioned Tactile Jigsaw Flashcards in Teaching Vocabulary to Children with Special Educational Needs

    Science.gov (United States)

    Król-Gierat, Werona

    2014-01-01

    The aim of the present paper is to show how captioned tactile jigsaw flashcards (CTJF) can be used in teaching English vocabulary to children with special educational needs. The idea of the following technique, inspired by Montessori's Three Period Lesson (1964, 1967a, 1967b), was presented by this author and colleague Dorota Beltkiewicz in March…

  14. Investigating Visual-Tactile Interactions over Time and Space in Adults with Autism

    Science.gov (United States)

    Poole, Daniel; Gowen, Emma; Warren, Paul A.; Poliakoff, Ellen

    2015-01-01

    It has been suggested that the sensory symptoms which affect many people with autism spectrum conditions (ASC) may be related to alterations in multisensory processing. Typically, the likelihood of interactions between the senses increases when information is temporally and spatially coincident. We explored visual-tactile interactions in adults…

  15. Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

    Directory of Open Access Journals (Sweden)

    Yixuan Ku

    2007-08-01

    Full Text Available Our previous studies on scalp-recorded event-related potentials (ERPs showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA to the ERP data, we found independent components (ICs located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC and the primary somatosensory cortex (SI. The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex that are involved in sensation and perception of various stimuli.

  16. Social facilitation of insect reproduction with motor-driven tactile stimuli.

    Science.gov (United States)

    Uzsák, Adrienn; Dieffenderfer, James; Bozkurt, Alper; Schal, Coby

    2014-05-22

    Tactile stimuli provide animals with important information about the environment, including physical features such as obstacles, and biologically relevant cues related to food, mates, hosts and predators. The antennae, the principal sensory organs of insects, house an array of sensory receptors for olfaction, gustation, audition, nociception, balance, stability, graviception, static electric fields, and thermo-, hygro- and mechanoreception. The antennae, being the anteriormost sensory appendages, play a prominent role in social interactions with conspecifics that involve primarily chemosensory and tactile stimuli. In the German cockroach (Blattella germanica) antennal contact during social interactions modulates brain-regulated juvenile hormone production, ultimately accelerating the reproductive rate in females. The primary sensory modality mediating this social facilitation of reproduction is antennal mechanoreception. We investigated the key elements, or stimulus features, of antennal contact that socially facilitate reproduction in B. germanica females. Using motor-driven antenna mimics, we assessed the physiological responses of females to artificial tactile stimulation. Our results indicate that tactile stimulation with artificial materials, some deviating significantly from the native antennal morphology, can facilitate female reproduction. However, none of the artificial stimuli matched the effects of social interactions with a conspecific female.

  17. Tactile acuity and lumbopelvic motor control in patients with back pain and healthy controls.

    Science.gov (United States)

    Luomajoki, H; Moseley, G L

    2011-04-01

    Voluntary lumbopelvic control is compromised in patients with back pain. Loss of proprioceptive acuity is one contributor to decreased control. Several reasons for decreased proprioceptive acuity have been proposed, but the integrity of cortical body maps has been overlooked. We investigated whether tactile acuity, a clear clinical signature of primary sensory cortex organisation, relates to lumbopelvic control in people with back pain. Forty-five patients with back pain and 45 age- and sex-matched healthy controls participated in this cross-sectional study. Tactile acuity at the back was assessed using two-point discrimination (TPD) threshold in vertical and horizontal directions. Voluntary motor control was assessed using an established battery of clinical tests. Patients performed worse on the voluntary lumbopelvic tasks than healthy controls did (p<0.001). TPD threshold was larger in patients (mean (SD)=61 (13) mm) than in healthy controls (44 (10) mm). Moreover, larger TPD threshold was positively related to worse performance on the voluntary lumbopelvic tasks (Pearson's r=0.49; p<0.001). Tactile acuity, a clear clinical signature of primary sensory cortex organisation, relates to voluntary lumbopelvic control. This relationship raises the possibility that the former contributes to the latter, in which case training tactile acuity may aid recovery and assist in achieving normal motor performance after back injury.

  18. Perceptual grouping over time within and across auditory and tactile modalities.

    Directory of Open Access Journals (Sweden)

    I-Fan Lin

    Full Text Available In auditory scene analysis, population separation and temporal coherence have been proposed to explain how auditory features are grouped together and streamed over time. The present study investigated whether these two theories can be applied to tactile streaming and whether temporal coherence theory can be applied to crossmodal streaming. The results show that synchrony detection between two tones/taps at different frequencies/locations became difficult when one of the tones/taps was embedded in a perceptual stream. While the taps applied to the same location were streamed over time, the taps applied to different locations were not. This observation suggests that tactile stream formation can be explained by population-separation theory. On the other hand, temporally coherent auditory stimuli at different frequencies were streamed over time, but temporally coherent tactile stimuli applied to different locations were not. When there was within-modality streaming, temporally coherent auditory stimuli and tactile stimuli were not streamed over time, either. This observation suggests the limitation of temporal coherence theory when it is applied to perceptual grouping over time.

  19. Demonstrating the application of dielectric polymer actuators for tactile feedback in a mobile consumer device.

    NARCIS (Netherlands)

    Moessinger, H.M.; Brokken, D.

    2010-01-01

    User interfaces of mobile consumer devices are becoming increasingly complex. To address this complexity touch-screen interfaces are used. They allow flexible design of the user interfaces but lack the tactile feedback mechanical buttons provide, limiting ease of use. Dielectric Elastomer Actuator

  20. [The effect of passive tactile stimulation in the brain activity of children with attention deficit].

    Science.gov (United States)

    Soria-Claros, M; Serrano-Marugan, I; Quintero, J; Ortiz, T

    2016-01-01

    The N200 and P300 evoked potentials have proved a useful tool in monitoring children with attention deficit disorder (ADD). To assess brain information processing by the N200 and P300 in touch modality in children with ADD. The P300 and N200 components to oddball tactile stimulation paradigm were recorded in an experimental group of 17 children with ADD at the beginning and the end of the daily training tactile stimulation, another 12 children with ADD and 21 control children without ADD who no received tactile stimulation. Three groups aged between 7 and 11 years. Results show a significant decrease in latency of N200 and P300 waves in the experimental group at the study end. N200 significant differences in the experimental group temporal parietal and occipital areas were found, while the differences in the P300 are located in postcentral and parietal areas. Systematic, orderly and organized tactile stimulation in children with ADD can be effective to improve N200-P300 latencies providing greater parietal brain plasticity, associated to perceptive attention.

  1. Self Touch to Touch Others: Designing the Tactile Sleeve for Social Touch

    NARCIS (Netherlands)

    Huisman, G.; Darriba Frederiks, A.; van Dijk, B.; Kröse, B.; Heylen, D.

    2013-01-01

    In this paper we present the concept and initial design stages of the TaSST (Tactile Sleeve for Social Touch). The TaSST consists of a soft pressure-sensitive input layer, and an output layer containing vibration motors. A touch to ones own sleeve is felt as a vibration on the sleeve of another

  2. Self touch to touch others : designing the tactile sleeve for social touch

    NARCIS (Netherlands)

    Huisman, Gijs; Darriba Frederiks, Aduén; Heylen, Dirk; Van Dijk, Betsy; Kröse, Ben

    2013-01-01

    In this paper we present the concept and initial design stages of the TaSST (Tactile Sleeve for Social Touch). The TaSST consists of a soft pressure-sensitive input layer, and an output layer containing vibration motors. A touch to ones own sleeve is felt as a vibration on the sleeve of another

  3. A flexible tactile-feedback touch screen using transparent ferroelectric polymer film vibrators

    International Nuclear Information System (INIS)

    Ju, Woo-Eon; Moon, Yong-Ju; Park, Cheon-Ho; Choi, Seung Tae

    2014-01-01

    To provide tactile feedback on flexible touch screens, transparent relaxor ferroelectric polymer film vibrators were designed and fabricated in this study. The film vibrator can be integrated underneath a transparent cover film or glass, and can also produce acoustic waves that cause a tactile sensation on human fingertips. Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] polymer was used as the relaxor ferroelectric polymer because it produces a large strain under applied electric fields, shows a fast response, and has excellent optical transparency. The natural frequency of this tactile-feedback touch screen was designed to be around 200–240 Hz, at which the haptic perception of human fingertips is the most sensitive; therefore, the resonance of the touch screen at its natural frequency provides maximum haptic sensation. A multilayered relaxor ferroelectric polymer film vibrator was also demonstrated to provide the same vibration power at reduced voltage. The flexible P(VDF-TrFE-CTFE) film vibrators developed in this study are expected to provide tactile sensation not only in large-area flat panel displays, but also in flexible displays and touch screens. (papers)

  4. Creative and Tactile Astronomy: Exploring the Universe Using All the Senses

    Science.gov (United States)

    Borges, Isabel; Canas, Lina; Alexander, Alison; Wiltsher, Ruth

    2015-01-01

    Creative and Tactile Astronomy is an educational project developed by English and Portuguese teachers. Isabel Borges and Lina Canas from Portugal and Alison Alexander and Ruth Wiltsher from the United Kingdom met for the first time at the 2013 Science on Stage Festival in Slubice-Oder, on the border between Germany and Poland. As a consequence of…

  5. Tactile pavement for guiding walking direction: An assessment of heading direction and gait stability.

    NARCIS (Netherlands)

    Pluyter, N.; de Wit, L.P.; Bruijn, S.M.; Plaisier, M.A.

    2015-01-01

    For maintaining heading direction while walking we heavily rely on vision. Therefore, walking in the absence of vision or with visual attention directed elsewhere potentially leads to dangerous situations. Here we investigated whether tactile information from the feet can be used as a (partial)

  6. The Advantage of Encoding Tactile Information for a Woman with Congenital Deaf-Blindness

    NARCIS (Netherlands)

    Janssen, M.J.; Nota, S.J.; Eling, P.A.T.M.; Ruijssenaars, A.J.J.M.

    2007-01-01

    Parents, caregivers and teachers feel a strong need to learn more about tactile information processing of deaf-blind persons, primarily in order to be able to offer adequate intervention strategies in their daily interactions and activities. The present study investigates perception and memory of

  7. Short-term memory for spatial configurations in the tactile modality: a comparison with vision.

    Science.gov (United States)

    Picard, Delphine; Monnier, Catherine

    2009-11-01

    This study investigates the role of acquisition constraints on the short-term retention of spatial configurations in the tactile modality in comparison with vision. It tests whether the sequential processing of information inherent to the tactile modality could account for limitation in short-term memory span for tactual-spatial information. In addition, this study investigates developmental aspects of short-term memory for tactual- and visual-spatial configurations. A total of 144 child and adult participants were assessed for their memory span in three different conditions: tactual, visual, and visual with a limited field of view. The results showed lower tactual-spatial memory span than visual-spatial, regardless of age. However, differences in memory span observed between the tactile and visual modalities vanished when the visual processing of information occurred within a limited field. These results provide evidence for an impact of acquisition constraints on the retention of spatial information in the tactile modality in both childhood and adulthood.

  8. Teaching a Student with Autism To Make Verbal Initiations: Effects of a Tactile Prompt.

    Science.gov (United States)

    Taylor, Bridget A.; Levin, Len

    1998-01-01

    A study examined effects of a tactile prompting device (the Gentle Reminder) as a prompt for a 9-year-old student with autism to make verbal initiations about play activities. Results indicate that the device serves as an effective, unobtrusive prompt for verbal initiations during play contexts and during cooperative learning activities.…

  9. Tactile sensory abilities in cerebral palsy: deficits in roughness and object discrimination

    Science.gov (United States)

    Wingert, Jason R; Burton, Harold; Sinclair, Robert J; Brunstrom, Janice E; Damiano, Diane L

    2008-01-01

    Motor deficits in cerebral palsy (CP) have been well documented; however, associated sensory impairment in CP remains poorly understood. We examined tactile object recognition in the hands using geometric shapes, common objects, and capital letters. Discrimination of tactile roughness was tested using paired horizontal gratings of varied groove widths passively translated across the index finger. We tested 17 individuals with hemiplegia (mean 13y 9mo [SD 5y 2mo]; 6 males, 11 females), 21 with diplegia (mean 14y 10mo [SD 7y]; 10 males, 11 females), and 21 without disabilities (mean 14y 10mo [SD 5y 1mo]; 11 males, 10 females). All participants with CP fell within level I or II of the Gross Motor Function Classification System and level I or II of the Manual Abilities Classification System. Individuals with CP were significantly less accurate compared with those without disabilities on all tactile object-recognition tasks using their non-dominant hand. Both groups of patients also had significantly higher thresholds for groove-width differences with both hands compared with those without disabilities. Within the group with diplegia, only roughness discrimination differed between hands, whereas within the group with hemiplegia, significant between-limb differences were present for all tasks. Despite mild motor deficits compared with the entire population of individuals with CP, this sample demonstrated ubiquitous tactile deficits. PMID:18811710

  10. Measurement of micro moulded parts by Computed Tomography and comparison to optical and tactile techniques

    DEFF Research Database (Denmark)

    Yagüe, J.A.; Tosello, Guido; Carmignato, S

    2011-01-01

    This paper focuses on dimensional verification of two micro-injection moulded components, selected from actual industrial productions, using CT metrological tools. In addition to CT scanning, also a tactile Coordinate Measuring Machine (CMM) with sub-micrometer uncertainty and an Optical Coordinate...

  11. Feeling Critically: A Report on ‘The Victorian Tactile Imagination’ Conference

    Directory of Open Access Journals (Sweden)

    Claire Wood

    2014-10-01

    Full Text Available This short piece reflects upon the way in which the themes of ‘The Victorian Tactile Imagination’ conference impacted upon participants and suggested a more ‘feeling’ direction for scholarship: an approach that cultivates respect for emotional intuition in critical practice while remaining sensitive to the challenges and limitations of such interpretations.

  12. Impact of Tactile Stimulation on Neurobehavioral Development of Premature Infants in Assiut City

    Science.gov (United States)

    Sayed, Atyat Mohammed Hassan; Youssef, Magda Mohamed E.; Hassanein, Farouk El-Sayed; Mobarak, Amal Ahmed

    2015-01-01

    Objective: To assess impact of tactile stimulation on neurobehavioral development of premature infants in Assiut City. Design: Quasi-experimental research design. Setting: The study was conducted in the Neonatal Intensive Care Unit at Assiut University Children Hospital, Assiut General Hospital, Health Insurance Hospital (ElMabarah Hospital) and…

  13. Flexible tactile sensing arrays for robotics: Architectural robustness and yield considerations

    Science.gov (United States)

    Barth, Phillip W.; Zdeblick, Mark J.; Kuc, Zenon; Beck, Patricia A.

    1986-01-01

    No tactile sensor array developed to date fills all, nor even most, of the requirements of: (1) many sensor elements to minimize tactile imaging time, (2) close spacing of small sensing elements for fine spatial discrimination, (3) ability to be molded to a convex fingertip surface for taction on concave surfaces, (4) ability to sense both force and temperature in order to fully mimic biological touch, (5) tolerance to overscale forces without damage, and (6) graceful failure in use, i.e., functional survival of most of the array when part of it is damaged, well. Several investigators have recently developed tactile sensing arrays suitable for imaging shapes on hard flat surfaces, but not well suited for taction on curved surfaces. Others have developed single tactile sensors suitable for incorporation into arrays, which will probably prove uneconomical when large numbers of sensors are needed. Still others have developed flexible capacitive arrays suitable for use on curved surfaces but incapable of obtaining temperature or proximity data. A technology is being developed herein suitable to the achievement of all of the above goals, and to incrementally demonstrate useful steps toward those goals.

  14. Effects of tactile and electrical stimuli upon release of vasoactive intestinal polypeptide in the mammalian penis.

    Science.gov (United States)

    Dixson, A F; Kendrick, K M; Blank, M A; Bloom, S R

    1984-02-01

    Plasma levels of vasoactive intestinal polypeptide (VIP) in the corpora cavernosa penis and dorsal penile veins greatly exceeded those measured in the limb or caudal veins during anaesthesia in various mammals (Bennett's wallaby, Barbary sheep, cheetah, puma, sooty mangabey, pigtail macaque and chimpanzee). Tactile stimulation of the penis immediately before or during collection of blood samples resulted in an increase. In the wallaby, VIP levels (mean +/- S.E.M.) in blood samples collected from the flaccid penis in the absence of tactile stimulation were very low (0.6 +/- 0.5 pmol/l). A 36-fold increase in VIP occurred after manual extension of the flaccid penis (24.8 +/- 3.2 pmol/l) or during manually stimulated erections (25.1 +/- 1.7 pmol/l). Electrical stimulation of erection produced no significant increase in VIP levels (2.3 +/- 0.9 pmol/l) unless accompanied by tactile stimulation (17.5 +/- 1.4 pmol/l). These studies provide the first demonstration that sensory feedback from the penis plays an important role in regulating vasoactive intestinal polypeptidergic activity. Since VIP is a potent vasodilator its release due to tactile stimuli during copulation may play a role in the maintenance of penile erection.

  15. Audio-tactile stimuli to improve health and well-being

    NARCIS (Netherlands)

    Dijk, Esko O.; van Erp, Johannes Bernardus Fransiscus; Kuyper, Ewoud; van Wolferen, Gerard; Nijholt, Antinus; Dijk, Esko O.; Lemmens, Paul M.C.

    2010-01-01

    From literature and through common experience it is known that stimulation of the tactile (touch) sense or auditory (hearing) sense can be used to improve people's health and well-being. For example, to make people relax, feel better, sleep better or feel comforted. In this position paper we propose

  16. Sex differences in tactile defensiveness in children with ADHD and their siblings

    NARCIS (Netherlands)

    Broring, T.; Rommelse, N.N.J.; Sergeant, J.A.; Scherder, E.J.A.

    2008-01-01

    Tactile defensiveness (TD) is a disturbance in sensory processing and is observed in some children with attention-deficit-hyperactivity disorder (ADHD). TD has been examined in male children with ADHD and in children with ADHD without differentiating by sex. As males and females with ADHD may differ

  17. Sex differences in tactile defensiveness in children with ADHD and their siblings.

    NARCIS (Netherlands)

    Broring, T.; Lambregts-Rommelse, N.N.J.; Sergeant, J.A.; Scherder, E.J.A.

    2008-01-01

    Tactile defensiveness (TD) is a disturbance in sensory processing and is observed in some children with attention-deficit-hyperactivity disorder (ADHD). TD has been examined in male children with ADHD and in children with ADHD without differentiating by sex. As males and females with ADHD may differ

  18. Gender differences in tactile defensiveness in school-aged children with ADHD and their siblings

    NARCIS (Netherlands)

    Bröring, T.; Rommelse, N.N.J.; Sergeant, J.A.; Scherder, E.J.A.

    2007-01-01

    Tactile defensiveness (TD) is a disturbance in sensory processing and is observed in some children with attention-deficit-hyperactivity disorder (ADHD). TD has been examined in male children with ADHD and in children with ADHD without differentiating by sex. As males and females with ADHD may differ

  19. Anticipation increases tactile stimulus processing in the ipsilateral primary somatosensory cortex.

    Science.gov (United States)

    van Ede, Freek; de Lange, Floris P; Maris, Eric

    2014-10-01

    Stimulus anticipation improves perception. To account for this improvement, we investigated how stimulus processing is altered by anticipation. In contrast to a large body of previous work, we employed a demanding perceptual task and investigated sensory responses that occur beyond early evoked activity in contralateral primary sensory areas: Stimulus-induced modulations of neural oscillations. For this, we recorded magnetoencephalography in 19 humans while they performed a cued tactile identification task involving the identification of either a proximal or a distal stimulation on the fingertips. We varied the cue-target interval between 0 and 1000 ms such that tactile targets occurred at various degrees of anticipation. This allowed us to investigate the influence of anticipation on stimulus processing in a parametric fashion. We observed that anticipation increases the stimulus-induced response (suppression of beta-band oscillations) originating from the ipsilateral primary somatosensory cortex. This occurs in the period in which the tactile memory trace is analyzed and is correlated with the anticipation-induced improvement in tactile perception. We propose that this ipsilateral response indicates distributed processing across bilateral primary sensory cortices, of which the extent increases with anticipation. This constitutes a new and potentially important mechanism contributing to perception and its improvement following anticipation. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

    Science.gov (United States)

    Ku, Yixuan; Ohara, Shinji; Wang, Liping; Lenz, Fred A; Hsiao, Steven S; Bodner, Mark; Hong, Bo; Zhou, Yong-Di

    2007-08-22

    Our previous studies on scalp-recorded event-related potentials (ERPs) showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA) to the ERP data, we found independent components (ICs) located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC) and the primary somatosensory cortex (SI). The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex) that are involved in sensation and perception of various stimuli.

  1. Restoring tactile awareness through the rubber hand illusion in cervical spinal cord injury.

    Science.gov (United States)

    Lenggenhager, Bigna; Scivoletto, Giorgio; Molinari, Marco; Pazzaglia, Mariella

    2013-10-01

    Bodily sensations are an important component of corporeal awareness. Spinal cord injury can leave affected body parts insentient and unmoving, leading to specific disturbances in the mental representation of one's own body and the sense of self. Here, we explored how illusions induced by multisensory stimulation influence immediate sensory signals and tactile awareness in patients with spinal cord injuries. The rubber hand illusion paradigm was applied to 2 patients with chronic and complete spinal cord injury of the sixth cervical spine, with severe somatosensory impairments in 2 of 5 fingers. Both patients experienced a strong illusion of ownership of the rubber hand during synchronous, but not asynchronous, stroking. They also, spontaneously reported basic tactile sensations in their previously numb fingers. Tactile awareness from seeing the rubber hand was enhanced by progressively increasing the stimulation duration. Multisensory illusions directly and specifically modulate the reemergence of sensory memories and enhance tactile sensation, despite (or as a result of) prior deafferentation. When sensory inputs are lost, and are later illusorily regained, the brain updates a coherent body image even several years after the body has become permanently unable to feel. This particular example of neural plasticity represents a significant opportunity to strengthen the sense of the self and the feelings of embodiment in patients with spinal cord injury.

  2. If I Remember Rightly--Tactile Illustrations Enable Greater Access to Books

    Science.gov (United States)

    Norman, Jackie

    2004-01-01

    A follow-up account of a mother's attempts to provide her blind daughter, now aged six, with knowledge of the physical world through the manipulation of three-dimensional objects and two-dimensional tactile representations. The case is made for the value of pictures to the development of children's understanding in general; and for the child who…

  3. Chills in Different Sensory Domains: Frisson Elicited by Acoustical, Visual, Tactile and Gustatory Stimuli

    Science.gov (United States)

    Grewe, Oliver; Katzur, Bjorn; Kopiez, Reinhard; Altenmuller, Eckart

    2011-01-01

    "Chills" (frisson manifested as goose bumps or shivers) have been used in an increasing number of studies as indicators of emotions in response to music (e.g., Craig, 2005; Guhn, Hamm, & Zentner, 2007; McCrae, 2007; Panksepp, 1995; Sloboda, 1991). In this study we present evidence that chills can be induced through aural, visual, tactile, and…

  4. Gestalt grouping effects on tactile information processing: when touching hands override spatial proximity.

    Science.gov (United States)

    Frings, Christian; Spence, Charles

    2013-04-01

    Using a tactile variant of the negative-priming paradigm, we analyzed the influence of Gestalt grouping on the ability of participants to ignore distracting tactile information. The distance between participants' hands, to which the target and distractor stimuli were simultaneously delivered, was varied (near/touching hands vs. hands far apart). In addition, the influence of touching hands was controlled, as participants wore gloves and their hands were blocked from vision by a cover. The magnitude of the tactile negative-priming effect was modulated by the interaction between hand separation and whether or not gloves were worn. When the hands were touching, negative priming emerged only while wearing gloves that prevented direct skin-to-skin contact. In contrast, when the separation between the participants' hands was larger, negative priming emerged only when gloves were not worn. This pattern of results is interpreted in terms of the competing influences of two interacting Gestalt principles--namely, connectedness and proximity--on the processing of tactile distractors.

  5. The Acquisition and Extinction of Fear of Painful Touch: a Novel Tactile Fear Conditioning Paradigm

    NARCIS (Netherlands)

    Biggs, Emma E; Meulders, Ann; Kaas, Amanda L; Goebel, R.; Vlaeyen, Johan W S

    2017-01-01

    Fear of touch, due to allodynia and spontaneous pain, is not well-understood. Experimental methods to advance this topic are lacking, and therefore we propose a novel tactile conditioning paradigm. Seventy-six pain-free participants underwent acquisition in both a predictable and unpredictable pain

  6. Functional connectivity in tactile object discrimination: a principal component analysis of an event related fMRI-Study.

    Science.gov (United States)

    Hartmann, Susanne; Missimer, John H; Stoeckel, Cornelia; Abela, Eugenio; Shah, Jon; Seitz, Rüdiger J; Weder, Bruno J

    2008-01-01

    Tactile object discrimination is an essential human skill that relies on functional connectivity between the neural substrates of motor, somatosensory and supramodal areas. From a theoretical point of view, such distributed networks elude categorical analysis because subtraction methods are univariate. Thus, the aim of this study was to identify the neural networks involved in somatosensory object discrimination using a voxel-based principal component analysis (PCA) of event-related functional magnetic resonance images. Seven healthy, right-handed subjects aged between 22 and 44 years were required to discriminate with their dominant hand the length differences between otherwise identical parallelepipeds in a two-alternative forced-choice paradigm. Of the 34 principal components retained for analysis according to the 'bootstrapped' Kaiser-Guttman criterion, t-tests applied to the subject-condition expression coefficients showed significant mean differences between the object presentation and inter-stimulus phases in PC 1, 3, 26 and 32. Specifically, PC 1 reflected object exploration or manipulation, PC 3 somatosensory and short-term memory processes. PC 26 evinced the perception that certain parallelepipeds could not be distinguished, while PC 32 emerged in those choices when they could be. Among the cerebral regions evident in the PCs are the left posterior parietal lobe and premotor cortex in PC 1, the left superior parietal lobule (SPL) and the right cuneus in PC 3, the medial frontal and orbitofrontal cortex bilaterally in PC 26, and the right intraparietal sulcus, anterior SPL and dorsolateral prefrontal cortex in PC 32. The analysis provides evidence for the concerted action of large-scale cortico-subcortical networks mediating tactile object discrimination. Parallel to activity in nodes processing object-related impulses we found activity in key cerebral regions responsible for subjective assessment and validation.

  7. The attentional-relevance and temporal dynamics of visual-tactile crossmodal interactions differentially influence early stages of somatosensory processing.

    Science.gov (United States)

    Popovich, Christina; Staines, W Richard

    2014-03-01

    Crossmodal interactions between relevant visual and tactile inputs can enhance attentional modulation at early stages in somatosensory cortices to achieve goal-oriented behaviors. However, the specific contribution of each sensory system during attentional processing remains unclear. We used EEG to investigate the effects of visual priming and attentional relevance in modulating somatosensory cortical responses. Healthy adults performed a sensory integration task that required scaled motor responses dependent on the amplitudes of tactile and visual stimuli. Participants completed an attentional paradigm comprised of 5 conditions that presented sequential or concurrent pairs of discrete stimuli with random amplitude variations: 1) tactile-tactile (TT), 2) visual-visual (VV), 3) visual-tactile simultaneous (SIM), 4) tactile-visual delay (TVd), and 5) visual-tactile delay (VTd), each with a 100 ms temporal delay between stimulus onsets. Attention was directed to crossmodal conditions and graded motor responses representing the summation of the 2 stimulus amplitudes were made. Results of somatosensory ERPs showed that the modality-specific components (P50, P100) were sensitive to i) the temporal dynamics of crossmodal interactions, and ii) the relevance of these sensory signals for behaviour. Notably, the P50 amplitude was greatest in the VTd condition, suggesting that presentation of relevant visual information for upcoming movement modulates somatosensory processing in modality-specific cortical regions, as early as the primary somatosensory cortex (SI).

  8. Can you see what you feel? Color and folding properties affect visual-tactile material discrimination of fabrics.

    Science.gov (United States)

    Xiao, Bei; Bi, Wenyan; Jia, Xiaodan; Wei, Hanhan; Adelson, Edward H

    2016-01-01

    Humans can often estimate tactile properties of objects from vision alone. For example, during online shopping, we can often infer material properties of clothing from images and judge how the material would feel against our skin. What visual information is important for tactile perception? Previous studies in material perception have focused on measuring surface appearance, such as gloss and roughness, and using verbal reports of material attributes and categories. However, in real life, predicting tactile properties of an object might not require accurate verbal descriptions of its surface attributes or categories. In this paper, we use tactile perception as ground truth to measure visual material perception. Using fabrics as our stimuli, we measure how observers match what they see (photographs of fabric samples) with what they feel (physical fabric samples). The data shows that color has a significant main effect in that removing color significantly reduces accuracy, especially when the images contain 3-D folds. We also find that images of draped fabrics, which revealed 3-D shape information, achieved better matching accuracy than images with flattened fabrics. The data shows a strong interaction between color and folding conditions on matching accuracy, suggesting that, in 3-D folding conditions, the visual system takes advantage of chromatic gradients to infer tactile properties but not in flattened conditions. Together, using a visual-tactile matching task, we show that humans use folding and color information in matching the visual and tactile properties of fabrics.

  9. Tactile-dependant corticomotor facilitation is influenced by discrimination performance in seniors

    Directory of Open Access Journals (Sweden)

    Tremblay François

    2010-03-01

    Full Text Available Abstract Background Active contraction leads to facilitation of motor responses evoked by transcranial magnetic stimulation (TMS. In small hand muscles, motor facilitation is known to be also influenced by the nature of the task. Recently, we showed that corticomotor facilitation was selectively enhanced when young participants actively discriminated tactile symbols with the tip of their index or little finger. This tactile-dependant motor facilitation reflected, for the large part, attentional influences associated with performing tactile discrimination, since execution of a concomitant distraction task abolished facilitation. In the present report, we extend these observations to examine the influence of age on the ability to produce extra motor facilitation when the hand is used for sensory exploration. Methods Corticomotor excitability was tested in 16 healthy seniors (58-83 years while they actively moved their right index finger over a surface under two task conditions. In the tactile discrimination (TD condition, participants attended to the spatial location of two tactile symbols on the explored surface, while in the non discrimination (ND condition, participants simply moved their finger over a blank surface. Changes in amplitude, in latency and in the silent period (SP duration were measured from recordings of motor evoked potentials (MEP in the right first dorsal interosseous muscle in response to TMS of the left motor cortex. Results Healthy seniors exhibited widely varying levels of performance with the TD task, older age being associated with lower accuracy and vice-versa. Large inter-individual variations were also observed in terms of tactile-specific corticomotor facilitation. Regrouping seniors into higher (n = 6 and lower performance groups (n = 10 revealed a significant task by performance interaction. This latter interaction reflected differences between higher and lower performance groups; tactile-related facilitation being

  10. Memory delay and haptic feedback influence the dissociation of tactile cues for perception and action.

    Science.gov (United States)

    Davarpanah Jazi, Shirin; Hosang, Stephanie; Heath, Matthew

    2015-05-01

    The somatosensory processing model (SPM) asserts that dissociable cortical processing streams mediate tactile perceptions and actions via relative and absolute cues, respectively (Dijkerman and de Haan, 2007). Accordingly, we sought to determine whether the introduction of a memory delay and/or physically touching a target object (i.e., haptic feedback) differentially influences the cues supporting tactile perceptions and actions. Participants used their right hand to manually estimate (i.e., perceptual task) or grasp (i.e., action task) differently sized objects placed on the palm of their left limb in conditions wherein the target object was available for the duration of the response (i.e., closed-loop condition), or was removed prior to response cuing (i.e., memory-guided condition). As well, trials were performed in conditions wherein the physical object was available (i.e., haptic feedback) or unavailable (i.e., no haptic feedback) to touch. Notably, we computed just-noticeable-difference (JND) scores to determine whether the aforementioned tasks and conditions adhered to - or violated - the relative properties of Weber's law. JNDs for manual estimations adhered to Weber's law across each condition - a finding supporting the SPM's contention that an immutable and relative percept supports tactile perceptions. In turn, JNDs for grasping violated Weber's law only when haptic feedback was available. Such a finding indicates that haptic feedback supports the absolute calibration between a tactile defined object and the required motor output. What is more, our study highlights that multiple somatosensory cues (i.e., tactile and haptic) support goal-directed grasping. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing.

    Directory of Open Access Journals (Sweden)

    Jan M Ache

    2015-07-01

    Full Text Available Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs. First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs 'coding-space' because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This

  12. Bilateral tactile hypersensitivity and neuroimmune responses after spared nerve injury in mice lacking vasoactive intestinal peptide.

    Science.gov (United States)

    Gallo, Alessandro; Leerink, Marjolein; Michot, Benoît; Ahmed, Eman; Forget, Patrice; Mouraux, André; Hermans, Emmanuel; Deumens, Ronald

    2017-07-01

    Vasoactive intestinal peptide (VIP) is one of the neuropeptides showing the strongest up-regulation in the nociceptive pathway after peripheral nerve injury and has been proposed to support neuropathic pain. Nevertheless, the story may be more complicated considering the known suppressive effects of the peptide on the immune reactivity of microglial cells, which have been heavily implicated in the onset and maintenance of pain after nerve injury. We here used mice deficient in VIP and the model of spared nerve injury, characterized by persistent tactile hypersensitivity. While tactile hypersensitivity developed similarly to wild type mice for the ipsilateral hindpaw, only transgenic mice showed a mirror-image tactile hypersensitivity in the contralateral hindpaw. This exacerbated neuropathic pain phenotype appeared to be mediated through a local mechanism acting at the level of the lumbar spinal cord as a distant nerve lesion in the front limb did not lead to hindpaw hypersensitivity in VIP-deficient mice. Innocuous tactile hindpaw stimulation was found to increase a neuronal activation marker in the bilateral superficial laminae of the lumbar dorsal horn of VIP-deficient, but not wild type mice, after SNI. A deeper study into the immune responsiveness to the nerve lesion also proved that VIP-deficient mice had a stronger early pro-inflammatory cytokine response and a more pronounced microglial reactivity compared to wild type controls. The latter was also observed at four weeks after spared nerve injury, a time at which bilateral tactile hypersensitivity persisted in VIP-deficient mice. These data suggest an action of VIP in neuropathic states that is more complicated than previously assumed. Future research is now needed for a deeper understanding of the relative contribution of receptors and fiber populations involved in the VIP-neuropathic pain link. Copyright © 2017. Published by Elsevier Inc.

  13. Evaluation of the possibility and response characteristics of laser-induced tactile sensation.

    Science.gov (United States)

    Kim, Hyung-Sik; Kim, Ji-Sun; Jung, Gu-In; Jun, Jae-Hoon; Park, Jong-Rak; Kim, Sung-Phil; Choi, Seungmoon; Park, Sung-Jun; Choi, Mi-Hyun; Chung, Soon-Cheol

    2015-08-18

    In this study, we examined the possibility and perceptual response characteristics of tactile sense induced by laser stimulation to the finger with different laser energy densities through human response experiments. 15 healthy adult males and 4 healthy adult females with an age of 22.6±2.2 years were tested. A frequency-doubled Q-switched laser was used with a wavelength of 532 nm and a 5 ns pulse width. The experimental trial spanned a total of 30 s and included a rest phase (19 s), a stimulation phase (7 s), and a response phase (4 s). During the rest phase, subjects kept their fingers comfortable. During the stimulation phase, one of three types of laser energy density (13.5, 16.6, 19.8 mJ/cm(2)) or a sham stimulation was used to irradiate the distal phalanx on the right index finger. During the response phase, the cognitive response to the laser stimulation was recorded by a PC by pressing the response button. The confusion matrix was configured to evaluate the possibility that the tactile sense was caused by the laser. In addition, changes in the response characteristics were observed according to three types of laser energy densities. From the analysis of the confusion matrix, the accuracy and sensitivity were not high. In contrast, precision and specificity were found to be high. Furthermore, there was a strong positive correlation between the laser irradiation and tactile perception, indicating that tactile sense can be induced using a laser in a mid-air manner. In addition, it was found that as the laser energy density increased, the tactile perception possibility also increased. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Facilitation of tactile working memory by top-down suppression from prefrontal to primary somatosensory cortex during sensory interference.

    Science.gov (United States)

    Savolainen, Petri; Carlson, Synnöve; Boldt, Robert; Neuvonen, Tuomas; Hannula, Henri; Hiltunen, Jaana; Salonen, Oili; Ma, Yuan-Ye; Pertovaara, Antti

    2011-06-01

    Tactile working memory (WM) is improved by increasing top-down suppression of interfering sensory processing in S1 via a link from the middle frontal gyrus (MFG) to S1. Here we studied in healthy subjects whether the efficacy of top-down suppression varies with submodality of sensory interference. Navigated stimulation of the MFG-S1 link significantly improved tactile WM performance when accompanied by tactile but not visual interference of memory maintenance. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Pre-stimulus alpha oscillations over somatosensory cortex predict tactile misperceptions.

    Science.gov (United States)

    Craddock, Matt; Poliakoff, Ellen; El-Deredy, Wael; Klepousniotou, Ekaterini; Lloyd, Donna M

    2017-02-01

    Fluctuations of pre-stimulus oscillatory activity in the somatosensory alpha band (8-14Hz) observed using human EEG and MEG have been shown to influence the detection of supra- and peri-threshold somatosensory stimuli. However, some reports of touch occur even without a stimulus. We investigated the possibility that pre-stimulus alpha oscillations might also influence these false reports of touch - known as tactile misperceptions. We recorded EEG while participants performed the Somatic Signal Detection Task (SSDT), in which participants must detect brief, peri-threshold somatosensory targets. We found that pre-stimulus oscillatory power in the somatosensory alpha range exhibited a negative linear relationship with reporting of touch at electrode clusters over both contralateral and ipsilateral somatosensory regions. As pre-stimulus alpha power increased, the probability of reporting a touch declined; as it decreased, the probability of reporting a touch increased. This relationship was stronger on trials without a somatosensory stimulus than on trials with a somatosensory stimulus, although was present for both trial types. Spatio-temporal cluster-based permutation analysis also found that pre-stimulus alpha was lower on trials when touch was reported - irrespective of whether it was present - over contralateral and ipsilateral somatosensory cortices, as well as left frontocentral areas. We argue that alpha power may reflect changes in response criterion rather than sensitivity alone. Low alpha power relates to a low barrier to reporting a touch even when one is not present, while high alpha power is linked to less frequent reporting of touch overall. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Tactile Approaches for Teaching Blind and Visually-Impaired Students in the Geosciences

    Science.gov (United States)

    Permenter, J. L.; Runyon, C.

    2003-12-01

    Hearing and touch are perhaps the two most important senses for teaching visually-impaired students in any context. Classroom lectures obviously emphasize the auditory aspects of learning, while touch is often relegated to either Braille texts or raised--line drawings for illustrative figures. From the student's perspective, some lecture topics, especially in the sciences, can be a challenge to grasp without additional stimuli. Geosciences have a distinct visual component that can be lost when teaching blind or visually-impaired students, particularly in the study of geomorphology and landform change. As an example, the matters raised concerning volcanic hazards can be difficult to envision without due attention to the limitations of visually-impaired students. Here, we suggest an example of a tactile approach for introducing the study of volcanoes and the hazards associated with them. Large, visually-stimulating images of a volcanic, populated region in southern Peru are supplied for those students who have poor but extant visual acuity, while precise, clay-based models of the region complement the images for those students, as well as for students who have no visual ability whatsoever. We use a model of the terrestrial volcano El Misti and the nearby city of Arequipa, Peru, to directly reflect the volcanic morphology and hazardous aspects of the terrain. The use of computer-generated digital elevation models from remote sensing imaging systems allows accurate replication of the regional topography. Instructors are able to modify these clay models to illustrate spatial and temporal changes in the region, allowing students to better grasp potential geological and geographical transformations over time. The models spawn engaging class discussions and help with designing hazard mitigation protocols.

  17. Can an electro-tactile vestibular substitution system improve balance in patients with unilateral vestibular loss under altered somatosensory conditions from the foot and ankle?

    Science.gov (United States)

    Vuillerme, N; Hlavackova, P; Franco, C; Diot, B; Demongeot, J; Payan, Y

    2011-01-01

    This pilot study aimed at assessing the feasibility and the effectiveness of an electro Electro-tactile Vestibular Substitution System (EVSS) in patients with unilateral vestibular loss under normal and altered somatosensory conditions from the foot and ankle. Four unilateral vestibular-defective patients voluntarily participated in the experiment. They were asked to stand upright as still as possible with their eyes closed in two Normal and Altered foot and ankle sensory conditions. In the Normal condition, the postural task was executed on a firm support surface constituted by the force platform. In the Altered condition, a 2-cm thick foam support surface was placed under the participants' feet. These two foot and ankle sensory conditions were executed under two No EVSS and EVSS experimental conditions. The No EVSS condition served as a control condition. In the EVSS condition, participants executed the postural task using a biofeedback system whose underlying principle consisted of supplying them with additional information about their head orientation/motion with respect to gravitational vertical through electro-tactile stimulation of their tongue. Centre of foot pressure displacements (CoP) were recorded using the force platform. Results showed that, relative to the No EVSS condition, the EVSS condition decreased CoP displacements in both the Normal and the Altered foot and ankle sensory conditions. Interestingly, the stabilizing effect was more pronounced in the Altered than in the Normal foot and ankle sensory condition. These preliminary results suggest that patients with unilateral vestibular loss were able to take advantage to a head position-based electro-tactile tongue biofeedback to mitigate the postural perturbation induced by alteration of somatosensory input from the foot and the ankle.

  18. Navigation with a passive brain based interface

    NARCIS (Netherlands)

    Erp, J.B.F. van; Werkhoven, P.J.; Thurlings, M.E.; Brouwer, A.-M.

    2009-01-01

    In this paper, we describe a Brain Computer Interface (BCI) for navigation. The system is based on detecting brain signals that are elicited by tactile stimulation on the torso indicating the desired direction.

  19. The effect of dual-hemisphere transcranial direct current stimulation over the parietal operculum on tactile orientation discrimination

    DEFF Research Database (Denmark)

    Fujimoto, Shuhei; Tanaka, Satoshi; Laakso, Ilkka

    2017-01-01

    The parietal operculum (PO) often shows ipsilateral activation during tactile object perception in neuroimaging experiments. However, the relative contribution of the PO to tactile judgment remains unclear. Here, we examined the effect of transcranial direct current stimulation (tDCS) over...... bilateral PO to test the relative contributions of the ipsilateral PO to tactile object processing. Ten healthy adults participated in this study, which had a double-blind, sham-controlled, cross-over design. Participants discriminated grating orientation during three tDCS and sham conditions. In the dual...... electrode. Importantly, dual-hemisphere tDCS with the anodal electrode over the left PO yielded a decreased threshold in the right finger compared with the uni-hemisphere tDCS condition. These results suggest that the ipsilateral PO inhibits tactile processing of grating orientation, indicating...

  20. Encoding of tactile stimuli by mechanoreceptors and interneurons of the medicinal leech

    Directory of Open Access Journals (Sweden)

    Jutta Kretzberg

    2016-10-01

    Full Text Available For many animals processing of tactile information is a crucial task in behavioral contexts like exploration, foraging and stimulus avoidance. The leech, having infrequent access to food, developed an energy efficient reaction to tactile stimuli, avoiding unnecessary muscle movements: The local bend behavior moves only a small part of the body wall away from an object touching the skin, while the rest of the animal remains stationary. Amazingly, the precision of this localized behavioral response is similar to the spatial discrimination threshold of the human fingertip, although the leech skin is innervated by an order of magnitude fewer mechanoreceptors and each midbody ganglion contains only 400 individually identified neurons in total. Prior studies suggested that this behavior is controlled by a three-layered feed-forward network, consisting of four mechanoreceptors (P cells, approximately 20 interneurons and 10 individually characterized motor neurons, all of which encode tactile stimulus location by overlapping, symmetrical tuning curves. Additionally, encoding of mechanical force was attributed to three types of mechanoreceptors reacting to distinct intensity ranges: T cells for touch, P cells for pressure and N cells for strong, noxious skin stimulation. In this study, we provide evidences that tactile stimulus encoding in the leech is more complex than previously thought. Combined electrophysiological, anatomical and voltage sensitive dye approaches indicate that P and T cells both play a major role in tactile information processing resulting in local bending. Our results indicate that tactile encoding neither relies on distinct force intensity ranges of different cell types, nor location encoding is restricted to spike count tuning. Instead, we propose that P and T cells form a mixed type population, which simultaneously employs temporal response features and spike counts for multiplexed encoding of touch location and force intensity

  1. Those are Your Legs: The Effect of Visuo-Spatial Viewpoint on Visuo-Tactile Integration and Body Ownership.

    Science.gov (United States)

    Pozeg, Polona; Galli, Giulia; Blanke, Olaf

    2015-01-01

    Experiencing a body part as one's own, i.e., body ownership, depends on the integration of multisensory bodily signals (including visual, tactile, and proprioceptive information) with the visual top-down signals from peripersonal space. Although it has been shown that the visuo-spatial viewpoint from where the body is seen is an important visual top-down factor for body ownership, different studies have reported diverging results. Furthermore, the role of visuo-spatial viewpoint (sometime also called first-person perspective) has only been studied for hands or the whole body, but not for the lower limbs. We thus investigated whether and how leg visuo-tactile integration and leg ownership depended on the visuo-spatial viewpoint from which the legs were seen and the anatomical similarity of the visual leg stimuli. Using a virtual leg illusion, we tested the strength of visuo-tactile integration of leg stimuli using the crossmodal congruency effect (CCE) as well as the subjective sense of leg ownership (assessed by a questionnaire). Fifteen participants viewed virtual legs or non-corporeal control objects, presented either from their habitual first-person viewpoint or from a viewpoint that was rotated by 90°(third-person viewpoint), while applying visuo-tactile stroking between the participants legs and the virtual legs shown on a head-mounted display. The data show that the first-person visuo-spatial viewpoint significantly boosts the visuo-tactile integration as well as the sense of leg ownership. Moreover, the viewpoint-dependent increment of the visuo-tactile integration was only found in the conditions when participants viewed the virtual legs (absent for control objects). These results confirm the importance of first person visuo-spatial viewpoint for the integration of visuo-tactile stimuli and extend findings from the upper extremity and the trunk to visuo-tactile integration and ownership for the legs.

  2. Sensorization of Robotic Hand Using Optical Three-Axis Tactile Sensor: Evaluation with Grasping and Twisting Motions

    OpenAIRE

    Hanafiah Yussof; Jiro Wada; Masahiro Ohka

    2010-01-01

    Problem statement: Sensitization of robot hand is still remaining as crucial issue since most of robot hand systems nowadays are only capable to grasp a predefined specific object. It is still difficult for robot hand system to realize human-like tactile sensation. Some common problems in robot hand system are low accuracy sensing device, sensors are not robust enough for long time work and heavy duties, inconsistence tactile sensing detection and difficulties in control of sensing fusion wit...

  3. Tactile massage and hypnosis as a health promotion for nurses in emergency care-a qualitative study

    OpenAIRE

    Airosa, Fanny; Andersson, Susanne K; Falkenberg, Torkel; Forsberg, Christina; Nordby-H?rnell, Elisabeth; ?hl?n, Gunnar; Sundberg, Tobias

    2011-01-01

    Abstract Background This study explores nursing personnel's experiences and perceptions of receiving tactile massage and hypnosis during a personnel health promotion project. Nursing in a short term emergency ward environment can be emotionally and physically exhausting due to the stressful work environment and the high dependency patient care. A health promotion project integrating tactile massage and hypnosis with conventional physical activities was therefore introduced for nursing personn...

  4. Efficacy of Directional Cues from a Tactile System for Target Orientation in Helicopter Extractions over Moving Targets

    Science.gov (United States)

    2013-01-01

    position. The results of this study have the potential to validate the use of sensor technology for navigation and spatial orientation when vision is...sufficiently robust to provide tactile cueing in the noisy helicopter environment. Recent technology developments in piezoelectric materials allow for...standard electric toothbrush . Altitude, position, velocity, and vector information is transmitted from the UH-60 flight simulator to the tactile system

  5. Brain Process for Perception of the “Out of the Body” Tactile Illusion for Virtual Object Interaction

    Directory of Open Access Journals (Sweden)

    Hye Jin Lee

    2015-04-01

    Full Text Available “Out of the body” tactile illusion refers to the phenomenon in which one can perceive tactility as if emanating from a location external to the body without any stimulator present there. Taking advantage of such a tactile illusion is one way to provide and realize richer interaction feedback without employing and placing actuators directly at all stimulation target points. However, to further explore its potential, it is important to better understand the underlying physiological and neural mechanism. As such, we measured the brain wave patterns during such tactile illusion and mapped out the corresponding brain activation areas. Participants were given stimulations at different levels with the intention to create veridical (i.e., non-illusory and phantom sensations at different locations along an external hand-held virtual ruler. The experimental data and analysis indicate that both veridical and illusory sensations involve, among others, the parietal lobe, one of the most important components in the tactile information pathway. In addition, we found that as for the illusory sensation, there is an additional processing resulting in the delay for the ERP (event-related potential and involvement by the limbic lobe. These point to regarding illusion as a memory and recognition task as a possible explanation. The present study demonstrated some basic understanding; how humans process “virtual” objects and the way associated tactile illusion is generated will be valuable for HCI (Human-Computer Interaction.

  6. Tactile stimulation interventions: influence of stimulation parameters on sensorimotor behavior and neurophysiological correlates in healthy and clinical samples.

    Science.gov (United States)

    Parianen Lesemann, Franca H; Reuter, Eva-Maria; Godde, Ben

    2015-04-01

    The pure exposure to extensive tactile stimulation, without the requirement of attention or active training, has been revealed to enhance sensorimotor functioning presumably due to an induction of plasticity in the somatosensory cortex. The induced effects, including increased tactile acuity and manual dexterity have repeatedly been observed in basic as well as clinical research. However, results vary greatly in respect to the strength and direction of the effects on the behavioral and on the brain level. Multiple evidences show that differences in the stimulation protocols (e.g., two vs. multiple stimulation sites) and parameters (e.g., duration, frequency, and amplitude) might contribute to this variability of effects. Nevertheless, stimulation protocols have not been comprehensively compared yet. Identifying favorable parameters for tactile stimulation interventions is especially important because of its possible application as a treatment option for patients suffering from sensory loss, maladaptive plasticity, or certain forms of motor impairment. This review aims to compare the effects of different tactile stimulation protocols and to assess possible implications for tactile interventions. Our goal is to identify ways of optimizing stimulation protocols to improve sensorimotor performance. To this end, we reviewed research on tactile stimulation in the healthy population, with a focus on the effectiveness of the applied parameters regarding psychophysiological measures. We discuss the association of stimulation-induced changes on the behavioral level with alterations in neural representations and response characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Tactile massage and hypnosis as a health promotion for nurses in emergency care-a qualitative study

    Science.gov (United States)

    2011-01-01

    Background This study explores nursing personnel's experiences and perceptions of receiving tactile massage and hypnosis during a personnel health promotion project. Nursing in a short term emergency ward environment can be emotionally and physically exhausting due to the stressful work environment and the high dependency patient care. A health promotion project integrating tactile massage and hypnosis with conventional physical activities was therefore introduced for nursing personnel working in this setting at a large university hospital in Sweden. Methods Four semi-structured focus group discussions were conducted with volunteer nursing personnel participants after the health promotion project had been completed. There were 16 participants in the focus groups and there were 57 in the health promotion intervention. The discussions were transcribed verbatim and analysed with qualitative content analysis. Results The findings indicated that tactile massage and hypnosis may contribute to reduced levels of stress and pain and increase work ability for some nursing personnel. The sense of well-being obtained in relation to health promotion intervention with tactile massage and hypnosis seemed to have positive implications for both work and leisure. Self-awareness, contentment and self-control may be contributing factors related to engaging in tactile massage and hypnosis that might help nursing personnel understand their patients and colleagues and helped them deal with difficult situations that occurred during their working hours. Conclusion The findings indicate that the integration of tactile massage and hypnosis in personnel health promotion may be valuable stress management options in addition to conventional physical activities. PMID:21961762

  8. Tactile massage and hypnosis as a health promotion for nurses in emergency care--a qualitative study.

    Science.gov (United States)

    Airosa, Fanny; Andersson, Susanne K; Falkenberg, Torkel; Forsberg, Christina; Nordby-Hörnell, Elisabeth; Ohlén, Gunnar; Sundberg, Tobias

    2011-10-01

    This study explores nursing personnel's experiences and perceptions of receiving tactile massage and hypnosis during a personnel health promotion project. Nursing in a short term emergency ward environment can be emotionally and physically exhausting due to the stressful work environment and the high dependency patient care. A health promotion project integrating tactile massage and hypnosis with conventional physical activities was therefore introduced for nursing personnel working in this setting at a large university hospital in Sweden. Four semi-structured focus group discussions were conducted with volunteer nursing personnel participants after the health promotion project had been completed. There were 16 participants in the focus groups and there were 57 in the health promotion intervention. The discussions were transcribed verbatim and analysed with qualitative content analysis. The findings indicated that tactile massage and hypnosis may contribute to reduced levels of stress and pain and increase work ability for some nursing personnel. The sense of well-being obtained in relation to health promotion intervention with tactile massage and hypnosis seemed to have positive implications for both work and leisure. Self-awareness, contentment and self-control may be contributing factors related to engaging in tactile massage and hypnosis that might help nursing personnel understand their patients and colleagues and helped them deal with difficult situations that occurred during their working hours. The findings indicate that the integration of tactile massage and hypnosis in personnel health promotion may be valuable stress management options in addition to conventional physical activities.

  9. 3D Printed Stretchable Capacitive Sensors for Highly Sensitive Tactile and Electrochemical Sensing.

    Science.gov (United States)

    Li, Kai; Wei, Hong; Liu, Wenguang; Meng, Hong; Zhang, Peixin; Yan, Chaoyi

    2018-02-15

    Developments of innovative strategies for the fabrication of stretchable sensors are of crucial importance for their applications in wearable electronic systems. In this work, we report the successful fabrication of stretchable capacitive sensors using a novel 3D printing method for highly sensitive tactile and electrochemical sensing applications. Unlike conventional lithographic or templated methods, the programmable 3D printing technique can fabricate complex device structures in a cost-effective and facile manner. We designed and fabricated stretchable capacitive sensors with interdigital and double-vortex designs and demonstrated their successful applications as tactile and electrochemical sensors. Especially, our stretchable sensors exhibited a detection limit as low as 1×10-6 M for NaCl aqueous solution, which could have significant potential applications when integrated in electronics skins. © 2018 IOP Publishing Ltd.

  10. Slip detection with accelerometer and tactile sensors in a robotic hand model

    Science.gov (United States)

    Al-Shanoon, Abdulrahman Abdulkareem S.; Anom Ahmad, Siti; Hassan, Mohd. Khair b.

    2015-11-01

    Grasp planning is an interesting issue in studies that dedicated efforts to investigate tactile sensors. This study investigated the physical force interaction between a tactile pressure sensor and a particular object. It also characterized object slipping during gripping operations and presented secure regripping of an object. Acceleration force was analyzed using an accelerometer sensor to establish a completely autonomous robotic hand model. An automatic feedback control system was applied to regrip the particular object when it commences to slip. Empirical findings were presented in consideration of the detection and subsequent control of the slippage situation. These findings revealed the correlation between the distance of the object slipping and the required force to regrip the object safely. This approach is similar to Hooke's law formula.

  11. Effect of DSP-4 induced central noradrenergic depletion on tactile learning in rat.

    Science.gov (United States)

    Rajabi, Soodeh; Shamsizadeh, Ali; Amini, Hossein; Shirazi, Mohsen; Allahtavakoli, Mohammad; Abbasnejad, Mehdi; Sheibani, Vahid

    2012-01-01

    There is general agreement that norepinephrine could modulate neuronal responses to non-monoaminergic synaptic inputs in the somatosensory cortex. In the present study, we investigated the effect of central norepinephrine depletion on tactile learning in rats. Central norepinephrine depletion was induced using 50 mg/kg of N-(2-chloroethyl)-N-ethyl-2 bromobenzylamine (DSP-4) and verified by high performance liquid chromatography. Memory performance was assessed 1 and 5 weeks after DSP-4 treatment using novel object recognition test. We observed a learning impairment in both DSP-4 groups, as the preference index was not significantly altered when compared to chance level (50%). These findings suggest that depletion of central norepinephrine by DSP-4 leads to impairment of the tactile learning in rats, which can last at least for 35 days.

  12. Transient storage of a tactile memory trace in primary somatosensory cortex.

    Science.gov (United States)

    Harris, Justin A; Miniussi, Carlo; Harris, Irina M; Diamond, Mathew E

    2002-10-01

    Working memory is known to involve prefrontal cortex and posterior regions of association cortex (e.g., the inferior temporal lobes). Here, we investigate the potential role of primary somatosensory cortex (SI) in a working memory task with tactile stimuli. Subjects were required to compare the frequencies of two vibrations separated by a retention interval of 1500 msec. Their performance was significantly disrupted when we delivered a pulse of transcranial magnetic stimulation (TMS) to the contralateral SI early (300 or 600 msec) in the retention interval. TMS did not affect tactile working memory if delivered to contralateral SI late in the retention interval (at 900 or 1200 msec), nor did TMS affect performance if delivered to the ipsilateral SI at any time point. Primary sensory cortex thus seems to act not only as a center for on-line sensory processing but also as a transient storage site for information that contributes to working memory.

  13. Image processing for a tactile/vision substitution system using digital CNN.

    Science.gov (United States)

    Lin, Chien-Nan; Yu, Sung-Nien; Hu, Jin-Cheng

    2006-01-01

    In view of the parallel processing and easy implementation properties of CNN, we propose to use digital CNN as the image processor of a tactile/vision substitution system (TVSS). The digital CNN processor is used to execute the wavelet down-sampling filtering and the half-toning operations, aiming to extract important features from the images. A template combination method is used to embed the two image processing functions into a single CNN processor. The digital CNN processor is implemented on an intellectual property (IP) and is implemented on a XILINX VIRTEX II 2000 FPGA board. Experiments are designated to test the capability of the CNN processor in the recognition of characters and human subjects in different environments. The experiments demonstrates impressive results, which proves the proposed digital CNN processor a powerful component in the design of efficient tactile/vision substitution systems for the visually impaired people.

  14. Tactile motion adaptation reduces perceived speed but shows no evidence of direction sensitivity.

    Directory of Open Access Journals (Sweden)

    Sarah McIntyre

    Full Text Available INTRODUCTION: While the directionality of tactile motion processing has been studied extensively, tactile speed processing and its relationship to direction is little-researched and poorly understood. We investigated this relationship in humans using the 'tactile speed aftereffect' (tSAE, in which the speed of motion appears slower following prolonged exposure to a moving surface. METHOD: We used psychophysical methods to test whether the tSAE is direction sensitive. After adapting to a ridged moving surface with one hand, participants compared the speed of test stimuli on the adapted and unadapted hands. We varied the direction of the adapting stimulus relative to the test stimulus. RESULTS: Perceived speed of the surface moving at 81 mms(-1 was reduced by about 30% regardless of the direction of the adapting stimulus (when adapted in the same direction, Mean reduction = 23 mms(-1, SD = 11; with opposite direction, Mean reduction = 26 mms(-1, SD = 9. In addition to a large reduction in perceived speed due to adaptation, we also report that this effect is not direction sensitive. CONCLUSIONS: Tactile motion is susceptible to speed adaptation. This result complements previous reports of reliable direction aftereffects when using a dynamic test stimulus as together they describe how perception of a moving stimulus in touch depends on the immediate history of stimulation. Given that the tSAE is not direction sensitive, we argue that peripheral adaptation does not explain it, because primary afferents are direction sensitive with friction-creating stimuli like ours (thus motion in their preferred direction should result in greater adaptation, and if perceived speed were critically dependent on these afferents' response intensity, the tSAE should be direction sensitive. The adaptation that reduces perceived speed therefore seems to be of central origin.

  15. Investigation On The Properties Of Concrete Tactile Paving Blocks Made With Recycled Tire Rubber

    OpenAIRE

    da Silva; Fabiana Maria; Barbosa; Luisa Andreia Gachet; Lintz; Rosa Cristina Cecche; Jacintho; Ana Elisabete P. G. A.

    2016-01-01

    Due to the increasing demand for buildings that meet accessibility standards and give access to all users, without restriction to people with a disability or reduced mobility, it arises the search for efficient and quality products. Aiming to develop a concrete paving block that contributes to sustainability in building and to accessibility in the built environment, in this paper recycled tire rubber (crumb rubber) was used as aggregate in concrete to produce tactile paving block. The replace...

  16. Teaching a student with autism to make verbal initiations: effects of a tactile prompt.

    OpenAIRE

    Taylor, B A; Levin, L

    1998-01-01

    This study examined the effects of a tactile prompting device (the Gentle Reminder) as a prompt for a student with autism to make verbal initiations about his play activities. A multiphase multielement design was used to assess the effects of the device in prompting initiations toward an adult in three different play contexts. Follow-up probes were conducted during cooperative learning activities with typically developing peers in the student's regular education class. The results suggest tha...

  17. Robotic and Virtual Reality BCIs Using Spatial Tactile and Auditory Oddball Paradigms

    OpenAIRE

    Rutkowski, Tomasz M.

    2016-01-01

    The paper reviews nine robotic and virtual reality (VR) brain–computer interface (BCI) projects developed by the author, in collaboration with his graduate students, within the BCI–lab research group during its association with University of Tsukuba, Japan. The nine novel approaches are discussed in applications to direct brain-robot and brain-virtual-reality-agent control interfaces using tactile and auditory BCI technologies. The BCI user intentions are decoded from the brainwaves in realti...

  18. Robust tactile sensory responses in finger area of primate motor cortex relevant to prosthetic control

    Science.gov (United States)

    Schroeder, Karen E.; Irwin, Zachary T.; Bullard, Autumn J.; Thompson, David E.; Bentley, J. Nicole; Stacey, William C.; Patil, Parag G.; Chestek, Cynthia A.

    2017-08-01

    Objective. Challenges in improving the performance of dexterous upper-limb brain-machine interfaces (BMIs) have prompted renewed interest in quantifying the amount and type of sensory information naturally encoded in the primary motor cortex (M1). Previous single unit studies in monkeys showed M1 is responsive to tactile stimulation, as well as passive and active movement of the limbs. However, recent work in this area has focused primarily on proprioception. Here we examined instead how tactile somatosensation of the hand and fingers is represented in M1. Approach. We recorded multi- and single units and thresholded neural activity from macaque M1 while gently brushing individual finger pads at 2 Hz. We also recorded broadband neural activity from electrocorticogram (ECoG) grids placed on human motor cortex, while applying the same tactile stimulus. Main results. Units displaying significant differences in firing rates between individual fingers (p  sensory information was present in M1 to correctly decode stimulus position from multiunit activity above chance levels in all monkeys, and also from ECoG gamma power in two human subjects. Significance. These results provide some explanation for difficulties experienced by motor decoders in clinical trials of cortically controlled prosthetic hands, as well as the general problem of disentangling motor and sensory signals in primate motor cortex during dextrous tasks. Additionally, examination of unit tuning during tactile and proprioceptive inputs indicates cells are often tuned differently in different contexts, reinforcing the need for continued refinement of BMI training and decoding approaches to closed-loop BMI systems for dexterous grasping.

  19. Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition

    Directory of Open Access Journals (Sweden)

    Yinghua Yu

    2018-01-01

    Full Text Available In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII receives projections from the unilateral primary somatosensory cortex (SI, and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI and a delayed match-to-sample (DMS task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left SII activity was greater than ipsilateral (right SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC. Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.

  20. Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition.

    Science.gov (United States)

    Yu, Yinghua; Yang, Jiajia; Ejima, Yoshimichi; Fukuyama, Hidenao; Wu, Jinglong

    2017-01-01

    In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII) receives projections from the unilateral primary somatosensory cortex (SI), and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI) and a delayed match-to-sample (DMS) task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left) SII activity was greater than ipsilateral (right) SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI) analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC). Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.