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Sample records for based tongue-placed tactile

  1. Controlling posture using a plantar pressure-based, tongue-placed tactile biofeedback system

    CERN Document Server

    Vuillerme, Nicolas; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The present paper introduces an original biofeedback system for improving human balance control, whose underlying principle consists in providing additional sensory information related to foot sole pressure distribution to the user through a tongue-placed tactile output device. To assess the effect of this biofeedback system on postural control during quiet standing, ten young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed reduced CoP displacements in the Biofeedback relative to the No-biofeedback condition. The present findings evidenced the ability of the central nervous system to efficiently integrate an artificial plantar-based, tongue-placed tactile biofeedback for controlling control posture during quiet standing.

  2. Controlling posture using a plantar pressure-based, tongue-placed tactile biofeedback system.

    OpenAIRE

    Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The present paper introduces an original biofeedback system for improving human balance control, whose underlying principle consists in providing additional sensory information related to foot sole pressure distribution to the user through a tongue-placed tactile output device. To assess the effect of this biofeedback system on postural control during quiet standing, ten young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback...

  3. How a plantar pressure-based, tongue-placed tactile biofeedback modifies postural control mechanisms during quiet standing

    CERN Document Server

    Vuillerme, Nicolas; Chenu, Olivier; Boisgontier, Matthieu; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The purpose of the present study was to determine the effects of a plantar pressure-based, tongue-placed tactile biofeedback on postural control mechanisms during quiet standing. To this aim, sixteen young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements, recorded using a force platform, were used to compute the horizontal displacements of the vertical projection the centre of gravity (CoGh) and those of the difference between the CoP and the vertical projection of the CoG (CoP-CoGv). Altogether, the present findings suggest that the main way the plantar pressure-based, tongue-placed tactile biofeedback improves postural control during quiet standing is via both a reduction of the correction thresholds and an increased efficiency of the corrective mechanism involving the CoGh displacements.

  4. A Plantar-pressure Based Tongue-placed Tactile Biofeedback System for Balance Improvement

    CERN Document Server

    Vuillerme, Nicolas; Pinsault, Nicolas; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Maintaining an upright stance represents a complex task, which is achieved by integrating sensory information from the visual, vestibular and somatosensory systems. When one of these sensory inputs becomes unavailable and/or inaccurate and/or unreliable, postural control generally is degraded. One way to solve this problem is to supplement and/or substitute limited/altered/missing sensory information by providing additional sensory information to the central nervous system via an alternative sensory modality. Along these lines, we developed an original biofeedback system [1] whose underlying principle consists in supplying the user with supplementary sensory information related to foot sole pressure distribution through a tongue-placed output device (Tongue Display Unit, "TDU" [2]). The purpose of the present experiment was to assess its effectiveness in improving balance in young healthy adults.

  5. Inter-individual variability in sensory weighting of a plantar pressure-based, tongue-placed tactile biofeedback for controlling posture.

    OpenAIRE

    Vuillerme, Nicolas; Pinsault, Nicolas; Boisgontier, Matthieu; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The purpose of the present experiment was to investigate whether the sensory weighting of a plantar pressure-based, tongue-placed tactile biofeedback for controlling posture could be subject to inter-individual variability. To achieve this goal, 60 young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Overall, results showed r...

  6. Inter-individual variability in sensory weighting of a plantar pressure-based, tongue-placed tactile biofeedback for controlling posture

    CERN Document Server

    Vuillerme, Nicolas; Boisgontier, Matthieu; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The purpose of the present experiment was to investigate whether the sensory weighting of a plantar pressure-based, tongue-placed tactile biofeedback for controlling posture could be subject to inter-individual variability. To achieve this goal, 60 young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Overall, results showed reduced CoP displacements in the Biofeedback relative to the No-biofeedback condition, evidencing the ability of the central nervous system to efficiently integrate an artificial plantar-based, tongue-placed tactile biofeedback for controlling posture during quiet standing. Results further showed a significant positive correlation between the CoP displacements measured in the No-biofeedback condition and the decrease in the CoP displacements induced by the use of the biofeedback. In other words, the degree of postural stab...

  7. Artificial Tongue-Placed Tactile Biofeedback for perceptual supplementation: application to human disability and biomedical engineering

    CERN Document Server

    Vuillerme, Nicolas; Moreau-Gaudry, Alexandre; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    The present paper aims at introducing the innovative technologies, based on the concept of "sensory substitution" or "perceptual supplementation", we are developing in the fields of human disability and biomedical engineering. Precisely, our goal is to design, develop and validate practical assistive biomedical and/technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. Proposed applications are dealing with: (1) pressure sores prevention in case of spinal cord injuries (persons with paraplegia, or tetraplegia); (2) ankle proprioceptive acuity improvement for driving assistance in older and/or disabled adults; and (3) balance control improvement to prevent fall in older and/or disabled adults. This paper presents results of three feasibility studies performed on young healthy adults.

  8. Improving human ankle joint position sense using an artificial tongue-placed tactile biofeedback

    CERN Document Server

    Vuillerme, N; Demongeot, J; Payan, Y; Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2006-01-01

    Proprioception is comprised of sensory input from several sources including muscle spindles, joint capsule, ligaments and skin. The purpose of the present experiment was to investigate whether the central nervous system was able to integrate an artificial biofeedback delivered through electrotactile stimulation of the tongue to improve proprioceptive acuity at the ankle joint. To address this objective, nine young healthy adults were asked to perform an active ankle-matching task with and without biofeedback. The underlying principle of the biofeedback consisted of supplying subjects with supplementary information about the position of their matching ankle position relative to their reference ankle position through a tongue-placed tactile output device (Tongue Display Unit). Measures of the overall accuracy and the variability of the positioning were determined using the absolute error and the variable error, respectively. Results showed more accurate and more consistent matching performances with than withou...

  9. Optimizing the Use of an Artificial Tongue-Placed Tactile Biofeedback for Improving Ankle Joint Position Sense in Humans

    CERN Document Server

    Vuillerme, N; Fleury, A; Demongeot, J; Payan, Y; Vuillerme, Nicolas; Chenu, Olivier; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2006-01-01

    The performance of an artificial tongue-placed tactile biofeedback device for improving ankle joint position sense was assessed in 12 young healthy adults using an active matching task. The underlying principle of this system consists of supplying individuals with supplementary information about the position of the matching ankle relative to the reference ankle position through a tongue-placed tactile output device generating electrotactile stimulation on a 36-point (6 X 6) matrix held against the surface of the tongue dorsum. Precisely, (1) no electrodes were activated when both ankles were in a similar angular position within a predetermined "angular dead zone" (ADZ); (2) 12 electrodes (2 X 6) of the anterior and posterior zones of the matrix were activated (corresponding to the stimulation of the front and rear portion of the tongue) when the matching ankle was in a too plantarflexed and dorsiflexed position relative to the reference ankle, respectively. Two ADZ values of 0.5° and 1.5° were...

  10. Tongue-placed tactile biofeedback suppresses the deleterious effects of muscle fatigue on joint position sense at the ankle

    CERN Document Server

    Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Whereas the acuity of the position sense at the ankle can be disturbed by muscle fatigue, it recently also has been shown to be improved, under normal ankle neuromuscular state, through the use of an artificial tongue-placed tactile biofeedback. The underlying principle of this biofeedback consisted of supplying individuals with supplementary information about the position of their matching ankle position relative to their reference ankle position through electrotactile stimulation of the tongue. Within this context, the purpose of the present experiment was to investigate whether this biofeedback could mitigate the deleterious effect of muscle fatigue on joint position sense at the ankle. To address this objective, sixteen young healthy university students were asked to perform an active ankle-matching task in two conditions of No-fatigue and Fatigue of the ankle muscles and two conditions of No-biofeedback and Biofeedback. Measures of the overall accuracy and the variability of the positioning were determin...

  11. Pressure sensor-based tongue-placed electrotactile biofeedback for balance improvement - Biomedical application to prevent pressure sores formation and falls

    CERN Document Server

    Vuillerme, Nicolas; Pinsault, Nicolas; Moreau-Gaudry, Alexandre; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. Proposed applications are dealing with: (1) pressure sores prevention in case of spinal cord injuries (persons with paraplegia, or tetraplegia); and (2) balance control improvement to prevent fall in older and/or disabled adults. This paper describes the architecture and the functioning principle of these biofeedback systems and presents preliminary results of two feasibility studies performed on young healthy adults.

  12. A Plantar-pressure Based Tongue-placed Tactile Biofeedback System for Balance Improvement.

    OpenAIRE

    Vuillerme, Nicolas; Chenu, Olivier; Pinsault, Nicolas; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Maintaining an upright stance represents a complex task, which is achieved by integrating sensory information from the visual, vestibular and somatosensory systems. When one of these sensory inputs becomes unavailable and/or inaccurate and/or unreliable, postural control generally is degraded. One way to solve this problem is to supplement and/or substitute limited/altered/missing sensory information by providing additional sensory information to the central nervous system via an alternative ...

  13. Tactile sensors based on conductive polymers

    Science.gov (United States)

    Castellanos-Ramos, Julian; Navas-Gonzalez, Rafael; Macicior, Haritz; Ochoteco, Estibalitz; Vidal-Verdú, Fernando

    2009-05-01

    This paper presents results from a few tactile sensors we have designed and fabricated. These sensors are based on a common approach that consists of placing a sheet of piezoresistive material on the top of a set of electrodes. If a force is exerted against the surface of the so obtained sensor, the contact area between the electrodes and the piezoresistive material changes. Therefore, the resistance at the interface changes. This is exploited as transconduction principle to measure forces and build advanced tactile sensors. For this purpose, we use a thin film of conductive polymers as the piezoresistive material. Specifically, a conductive water-based ink of these polymers is deposited by spin coating on a flexible plastic sheet, giving as a result a smooth, homogeneous and conducting thin film on it. The main interest in this procedure is it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work we present results from sensors made with two technologies. First, we have used a Printed Circuit Board technology to fabricate the set of electrodes and addressing tracks. Then we have placed the flexible plastic sheet with the conductive polymer film on them to obtain the sensor. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with a screen printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. There is a very interesting difference with the other sensors, that consists of the use of an elastomer as insulation material between conductive layers. Besides of its role as insulator, this elastomer allows the modification of the force versus resistance relationship. It also improves the dynamic response of the sensor because it implements a restoration force that helps the sensor to relax quicker when the force is taken off.

  14. Tactile Sensors Based on Conductive Polymers

    OpenAIRE

    Macicior, Haritz; Sikora, Tomasz; Ochoteco, Estíbalitz; Castellanos Ramos, Julián; Navas González, Rafael Jesús; Vidal Verdú, Fernando

    2010-01-01

    This paper presents results from a selection of tactile sensors that have been designed and fabricated. These sensors are based on a common approach that consists in placing a sheet of piezoresistive material on the top of a set of electrodes. We use a thin film of conductive polymer as the piezoresistive mate¬rial. Specifically, a conductive water-based ink of this polymer is deposited by spin coating on a flexible plastic sheet, giving it a smooth, homogeneous and conducting thin film. The ...

  15. Improving human ankle joint position sense using an artificial tongue-placed tactile biofeedback

    OpenAIRE

    Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan

    2006-01-01

    Proprioception is comprised of sensory input from several sources including muscle spindles, joint capsule, ligaments and skin. The purpose of the present experiment was to investigate whether the central nervous system was able to integrate an artificial biofeedback delivered through electrotactile stimulation of the tongue to improve proprioceptive acuity at the ankle joint. To address this objective, nine young healthy adults were asked to perform an active ankle-matching task with and wit...

  16. Wearable tactile sensor based on flexible microfluidics.

    Science.gov (United States)

    Yeo, Joo Chuan; Yu, Jiahao; Koh, Zhao Ming; Wang, Zhiping; Lim, Chwee Teck

    2016-08-16

    In this work, we develop a liquid-based thin film microfluidic tactile sensor of high flexibility, robustness and sensitivity. The microfluidic elastomeric structure comprises a pressure sensitive region and parallel arcs that interface with screen-printed electrodes. The microfluidic sensor is functionalized with a highly conductive metallic liquid, eutectic gallium indium (eGaIn). Microdeformation on the pressure sensor results in fluid displacement which corresponds to a change in electrical resistance. By emulating parallel electrical circuitry in our microchannel design, we reduced the overall electrical resistance of the sensor, therefore enhancing its device sensitivity. Correspondingly, we report a device workable within a range of 4 to 100 kPa and sensitivity of up to 0.05 kPa(-1). We further demonstrate its robustness in withstanding >2500 repeated loading and unloading cycles. Finally, as a proof of concept, we demonstrate that the sensors may be multiplexed to detect forces at multiple regions of the hand. In particular, our sensors registered unique electronic signatures in object grasping, which could provide better assessment of finger dexterity. PMID:27438370

  17. High-Speed Tactile Sensing for Array-Type Tactile Sensor and Object Manipulation Based on Tactile Information

    Directory of Open Access Journals (Sweden)

    Wataru Fukui

    2011-01-01

    Full Text Available We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous manipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor has a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number of measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the measurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through experiments.

  18. 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.

  19. Tactile Sensors: MoS2 -Based Tactile Sensor for Electronic Skin Applications (Adv. Mater. 13/2016).

    Science.gov (United States)

    Park, Minhoon; Park, Yong Ju; Chen, Xiang; Park, Yon-Kyu; Kim, Min-Seok; Ahn, Jong-Hyun

    2016-04-01

    A tactile sensor based on a MoS2 strain gauge and a graphene electrode is integrated on a finger tip by M.-S. Kim, J.-H. Ahn, and co-workers, as described on page 2556. The MoS2 and graphene can be conformally attached onto a thumbprint thanks to their outstanding mechanical flexibility. The MoS2 -based tactile sensor, showing excellent sensing properties, is expected to provide great opportunities for electronic-skin and wearable-electronics applications. PMID:27037944

  20. A biomimetic tactile sensing system based on polyvinylidene fluoride film

    Science.gov (United States)

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements.

  1. Micro-vibration-based slip detection in tactile force sensors.

    Science.gov (United States)

    Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan

    2014-01-01

    Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect slipping in other force sensors based on flexible parts. In particular, we show and compare the slip detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor. PMID:24394598

  2. Micro-Vibration-Based Slip Detection in Tactile Force Sensors

    Directory of Open Access Journals (Sweden)

    Raul Fernandez

    2014-01-01

    Full Text Available Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect slipping in other force sensors based on flexible parts. In particular, we show and compare the slip detection with: (i a flexible finger, designed by the authors, acting as a force sensor; (ii the finger torque sensor of a commercial robotic hand; (iii a commercial six-axis force sensor mounted on the wrist of a robot; and (iv a fingertip piezoresistive matrix sensor.

  3. Micro-Vibration-Based Slip Detection in Tactile Force Sensors

    OpenAIRE

    Raul Fernandez; Ismael Payo; Andres S. Vazquez; Jonathan Becedas

    2014-01-01

    Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, slip detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect slipping, the majority being a combination of complex sensors with complex algorithms. In this paper, ...

  4. Simulations of an Optical Tactile Sensor Based on Computer Tomography

    Science.gov (United States)

    Ohka, Masahiro; Sawamoto, Yasuhiro; Zhu, Ning

    In order to create a robotic tactile sensor of thin shape, a new optical tactile sensor is developed by applying a CT (Computer Tomography) algorithm. The present tactile sensor is comprised of infrared emitting diode arrays, receiving phototransistor arrays and a transparent acrylic plate and a black rubber sheet with projections. Infrared rays emitted from the diode array are directed into one end of the plate and their intensity distribution is measured by the phototransistor array mounted on the other end. If the CT algorithm is directly applied to the tactile sensor, there are two shortcomings: the shape of the sensing area is limited to a circular region and there is a long calculation time. Thus, a new CT algorithm oriented to tactile sensing is proposed for overcoming these problems. In the present algorithm, a square sensing area is divided into an N-by-N array and algebraic equations are derived from the relationship between the input and output light intensities on the assumed light projections. Several reconstruction methods are considered for obtaining pressure values caused in the squares. In the present study, the ART (Algebraic Reconstruction Technique) and LU decomposition methods were employed, and these methods were compared to select the best reconstruction method. In a series of simulations, it was found that the LU decomposition method held an advantage for the present type of tactile sensor because of its robustness against disturbance and short calculation time.

  5. Force/torque and tactile sensors for sensor-based manipulator control

    Science.gov (United States)

    Vanbrussel, H.; Belieen, H.; Bao, Chao-Ying

    1989-01-01

    The autonomy of manipulators, in space and in industrial environments, can be dramatically enhanced by the use of force/torque and tactile sensors. The development and future use of a six-component force/torque sensor for the Hermes Robot Arm (HERA) Basic End-Effector (BEE) is discussed. Then a multifunctional gripper system based on tactile sensors is described. The basic transducing element of the sensor is a sheet of pressure-sensitive polymer. Tactile image processing algorithms for slip detection, object position estimation, and object recognition are described.

  6. A Tent Map Based A/D Conversion Circuit for Robot Tactile Sensor

    Directory of Open Access Journals (Sweden)

    Jianxin Liu

    2013-01-01

    Full Text Available Force and tactile sensors are basic elements for robot perception and control, which call for large range and high-accuracy amplifier. In this paper, a novel A/D conversion circuit for array tactile sensor is proposed by using nonlinear tent map phenomenon, which is characterized by sensitivity to small signal and nonlinear amplifying function. The tent map based A/D conversion circuits can simultaneously realize amplifying and A/D converting functions. The proposed circuit is not only simple but also easy to integrate and produce. It is very suited for multipath signal parallel sampling and A/D converting of large array tactile sensor.

  7. Refreshable tactile displays based on bistable electroactive polymer

    Science.gov (United States)

    Niu, Xiaofan; Brochu, Paul; Salazar, Brandon; Pei, Qibing

    2011-04-01

    Refreshable tactile displays can significantly improve the education of blind children and the quality of life of people with severe vision impairment. A number of actuator technologies have been investigated. Bistable Electroactive Polymer (BSEP) appears to be well suited for this application. The BSEP exhibits a bistable electrically actuated strain as large as 335%. We present improved refreshable tactile display devices fabricated on thin plastic sheets. Stacked BSEP films were employed to meet the requirements in raised dot height and supporting force. The bistable nature of the actuation reduces the power consumption and simplifies the device operation.

  8. A WIRELESS EMBEDDED TONGUE TACTILE BIOFEEDBACK SYSTEM FOR BALANCE CONTROL

    OpenAIRE

    Vuillerme, Nicolas; Pinsault, Nicolas; Chenu, Olivier; Fleury, Anthony; Payan, Yohan; Demongeot, Jacques

    2008-01-01

    We describe the architecture of an original biofeedback system for balance improvement for fall prevention and present results of a feasibility study. The underlying principle of this biofeedback consists of providing supplementary information related to foot sole pressure distribution through a wireless embedded tongue-placed tactile output device. Twelve young healthy adults voluntarily participated in this experiment. They were asked to stand as immobile as possible with their eyes closed ...

  9. Flexible tactile sensing based on piezoresistive composites: a review.

    Science.gov (United States)

    Stassi, Stefano; Cauda, Valentina; Canavese, Giancarlo; Pirri, Candido Fabrizio

    2014-01-01

    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. PMID:24638126

  10. 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.

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

    OpenAIRE

    Stefano Stassi; Valentina Cauda; Giancarlo Canavese; Candido Fabrizio Pirri

    2014-01-01

    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 c...

  12. A voice coil motor based measuring force control system for tactile scanning profiler

    Science.gov (United States)

    Feng, Shengdong; Liu, Xiaojun; Chen, Liangzhou; Zhou, Liping; Lu, Wenlong

    2015-02-01

    In tactile scanning profiler, the measuring force would change in a wide range when it was used for profile measurement in a large range, which could possibly destroy the measured surface. To solve the problem, measuring force control system for tactile scanning profiler was needed. In the paper, a voice coil motor-based measuring force control system for tactile scanning profiler was designed. In the design, a low stiffness coefficient spring was used to provide contact force, while a voice coil motor (VCM) to balance the spring force so that the contact force could be kept for constant measuring force. A VCM was designed specially, and for active measuring force control, a precision current source circuit under the control of a DSP unit was designed to drive the VCM. The performance of voice coil motor based measuring force control system had been tested, and its good characteristics were verified.

  13. Contact Region Estimation Based on a Vision-Based Tactile Sensor Using a Deformable Touchpad

    Directory of Open Access Journals (Sweden)

    Yuji Ito

    2014-03-01

    Full Text Available A new method is proposed to estimate the contact region between a sensor and an object using a deformable tactile sensor. The sensor consists of a charge-coupled device (CCD camera, light-emitting diode (LED lights and a deformable touchpad. The sensor can obtain a variety of tactile information, such as the contact region, multi-axis contact force, slippage, shape, position and orientation of an object in contact with the touchpad. The proposed method is based on the movements of dots printed on the surface of the touchpad and classifies the contact state of dots into three types—A non-contacting dot, a sticking dot and a slipping dot. Considering the movements of the dots with noise and errors, equations are formulated to discriminate between the contacting dots and the non-contacting dots. A set of the contacting dots discriminated by the formulated equations can construct the contact region. Next, a method is developed to detect the dots in images of the surface of the touchpad captured by the CCD camera. A method to assign numbers to dots for calculating the displacements of the dots is also proposed. Finally, the proposed methods are validated by experimental results.

  14. MEMS-based ZnO Piezoelectric Tactile Sensor for Minimally Invasive Surgery

    Institute of Scientific and Technical Information of China (English)

    Minrui Wang; Jing Wang; Yan Cui; Liding Wang

    2006-01-01

    This paper reports the design and fabrication of a MEMS-based ZnO piezoelectric tactile sensor, which can be integrated on to the endoscopic grasper used in minimally invasive surgery (MIS). The sensor includes a silicon substrate,platinum bottom electrode, platinum top electrode, and a ZnO piezoelectric thin film, which is sandwiched between the two-electrode layers. The sensitivity of the micro-force sensor is analyzed in theory and the sensor exhibits high sensitivity about 7 pc/uN. The application of this tactile sensor to MIS will allow the surgeon feeling the touch force between the endoscopic grasper and tissue in real-time, and manipulating the tissue safely.

  15. 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

    2015-08-01

    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. PMID:26736798

  16. A CMOS-Based Tactile Sensor for Continuous Blood Pressure Monitoring

    CERN Document Server

    Kirstein, K -U; Salo, T; Hagleitner, C; Vancura, T; Hierlemann, A

    2011-01-01

    A monolithic integrated tactile sensor array is presented, which is used to perform non-invasive blood pressure monitoring of a patient. The advantage of this device compared to a hand cuff based approach is the capability of recording continuous blood pressure data. The capacitive, membrane-based sensor device is fabricated in an industrial CMOS-technology combined with post-CMOS micromachining. The capacitance change is detected by a S?-modulator. The modulator is operated at a sampling rate of 128kS/s and achieves a resolution of 12bit with an external decimation filter and an OSR of 128.

  17. Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array.

    Science.gov (United States)

    Hamed, Abbi; Masamune, Ken; Tse, Zion Tsz Ho; Lamperth, Michael; Dohi, Takeyoshi

    2012-07-01

    Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions. PMID:22913103

  18. A Large Area Tactile Sensor Patch Based on Commercial Force Sensors

    Directory of Open Access Journals (Sweden)

    Alfonso García-Cerezo

    2011-05-01

    Full Text Available This paper reports the design of a tactile sensor patch to cover large areas of robots and machines that interact with human beings. Many devices have been proposed to meet such a demand. These realizations are mostly custom-built or developed in the lab. The sensor of this paper is implemented with commercial force sensors. This has the benefit of a more foreseeable response of the sensor if its behavior is understood as the aggregation of readings from all the individual force sensors in the array. A few reported large area tactile sensors are also based on commercial sensors. However, the one in this paper is the first of this kind based on the use of polymeric commercial force sensing resistors (FSR as unit elements of the array or tactels, which results in a robust sensor. The paper discusses design issues related to some necessary modifications of the force sensor, its assembly in an array, and the signal conditioning. The patch has 16 × 9 force sensors mounted on a flexible printed circuit board with a spatial resolution of 18.5 mm. The force range of a tactel is 6 N and its sensitivity is 0.6 V/N. The array is read at a rate of 78 frames per second. Finally, two simple application examples are also carried out with the sensor mounted on the forearm of a rescue robot that communicates with the sensor through a CAN bus.

  19. Research on pressure tactile sensing technology based on fiber Bragg grating array

    Science.gov (United States)

    Song, Jinxue; Jiang, Qi; Huang, Yuanyang; Li, Yibin; Jia, Yuxi; Rong, Xuewen; Song, Rui; Liu, Hongbin

    2015-09-01

    A pressure tactile sensor based on the fiber Bragg grating (FBG) array is introduced in this paper, and the numerical simulation of its elastic body was implemented by finite element software (ANSYS). On the basis of simulation, fiber Bragg grating strings were implanted in flexible silicone to realize the sensor fabrication process, and a testing system was built. A series of calibration tests were done via the high precision universal press machine. The tactile sensor array perceived external pressure, which is demodulated by the fiber grating demodulation instrument, and three-dimension pictures were programmed to display visually the position and size. At the same time, a dynamic contact experiment of the sensor was conducted for simulating robot encountering other objects in the unknown environment. The experimental results show that the sensor has good linearity, repeatability, and has the good effect of dynamic response, and its pressure sensitivity was 0.03 nm/N. In addition, the sensor also has advantages of anti-electromagnetic interference, good flexibility, simple structure, low cost and so on, which is expected to be used in the wearable artificial skin in the future.

  20. 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.

  1. 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.

  2. Tactile refreshable screen based on magneto-rheological fluids for map exploration and navigation tasks

    Science.gov (United States)

    Bolzmacher, C.; Changeon, G.; Plaud, V.; Roselier, S.; Lozada, J.; Hafez, M.

    2011-06-01

    Human-machine interfaces can convey information via visual, audio and/or haptic cues during a navigation task. The visual and audio technologies are mature, whereas research has to be focused on haptic technologies for mobile devices. In this work, a tactile refreshable screen is proposed which allows its user the exploration of maps and navigational tasks in an egocentric perspective. The proposed device consists of an array of actuators which can display various patterns. The actuation technology is based on a magneto-rheological fluid which is injected in a chamber with an elastomeric membrane using a micro pump. The fluid pressure deforms the membrane in order to display a pattern. The fluid properties are used to form a valve in each cell. A permanent magnet, a ferromagnetic core, and a coil form a closed magnetic circuit with a gap where the magneto-rheological fluid can flow; the magnetic field interacts with the fluid and prevents the filling or draining of the chamber. Applying a current to the coil counteracts the magnetic field generated by the magnet and the fluid can circulate freely in order to inflate or deflate the membrane. The design, fabrication and integration of the device in addition to the results of finite element simulations and experimental measurements are reported.

  3. A Tactile Carina Nebula

    Science.gov (United States)

    Grice, Noreen A.; Mutchler, M.

    2010-01-01

    Astronomy was once considered a science restricted to fully sighted participants. But in the past two decades, accessible books with large print/Braille and touchable pictures have brought astronomy and space science to the hands and mind's eye of students, regardless of their visual ability. A new universally-designed tactile image featuring the Hubble mosaic of the Carina Nebula is being presented at this conference. The original dataset was obtained with Hubble's Advanced Camera for Surveys (ACS) hydrogen-alpha filter in 2005. It became an instant icon after being infused with additional color information from ground-based CTIO data, and released as Hubble's 17th anniversary image. Our tactile Carina Nebula promotes multi-mode learning about the entire life-cycle of stars, which is dramatically illustrated in this Hubble mosaic. When combined with descriptive text in print and Braille, the visual and tactile components seamlessly reach both sighted and blind populations. Specific touchable features of the tactile image identify the shapes and orientations of objects in the Carina Nebula that include star-forming regions, jets, pillars, dark and light globules, star clusters, shocks/bubbles, the Keyhole Nebula, and stellar death (Eta Carinae). Visit our poster paper to touch the Carina Nebula!

  4. 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.

  5. Piezoelectric Transducers Based on Aluminum Nitride and Polyimide for Tactile Applications

    OpenAIRE

    Mastronardi, Vincenzo Mariano

    2016-01-01

    The development of micro systems with smart sensing capabilities is paving the way to progresses in the technology for humanoid robotics. The importance of sensory feedback has been recognized the enabler of a high degree of autonomy for robotic systems. In tactile applications, it can be exploited not only to avoid objects slipping during their manipulation but also to allow safe interaction with humans and unknown objects and environments. In order to ensure the minimal deformation of an ob...

  6. A Principle and Characteristics of a Flexible and Stretchable Tactile Sensor Based on Static Electricity

    OpenAIRE

    Tada, Yasunori; Inoue, Masahiro; Kawasaki, Toshimi; Kawahito, Yasushi; Ishiguro, Hiroshi; Suganuma, Katsuaki

    2008-01-01

    This paper proposed the novel tactile sensor utilized the static electricity and the electrostatic induction phenomenon. The sensor consisted of the charged body and the conductive sensor element only. Additionally, the structure of the sensor was very simple. The arbitrary materials were utilized as the sensor. In this paper, the sensor element and the charged body were made of the conductive and the insulated silicone rubber, respectively. Therefore, the developed sensor was flexible and st...

  7. Depth camera-based 3D hand gesture controls with immersive tactile feedback for natural mid-air gesture interactions.

    Science.gov (United States)

    Kim, Kwangtaek; Kim, Joongrock; Choi, Jaesung; Kim, Junghyun; Lee, Sangyoun

    2015-01-01

    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. PMID:25580901

  8. 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.

  9. Tactile Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project has developed a set of tactile display garments that will be used to evaluate various tactile display methodologies. The garments include two sleeves...

  10. 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...... both spatial distribution of pressure and dynamic events such as contact, release of contact and slip. Data acquisition and object recognition applications are described and it is proposed that such a sensor could be used in robotic grippers to improve object recognition, manipulation of objects...

  11. Advanced approaches to high precision MEMS metrology based on interferometric,confocal,and tactile techniques

    Institute of Scientific and Technical Information of China (English)

    Peter Lehmenn

    2008-01-01

    Geometrical features of micro-systems can be determined by either tactile or optical profiling techniques,which show different non-linear transfer characteristics.This has to be considered especially,if the instrumcnts operate close to their physical limitations.Depending on the specific measuring task either point-wise or areal optical measurement may be advantageous.Hence,examples for boIh approaches are discussed.Furthermore,systematic effects,which are related to the measuring principle have to be taken into account,e.g.if sharp edges or slopes ale present on the measuring object.As it is shown,for white-light interferometry these difficulties can be solved by a two-wavelength technique.

  12. Development of a versatile capacitive tactile sensor based on transparent flexible materials integrating an excellent sensitivity and a high resolution

    Directory of Open Access Journals (Sweden)

    H. Z. Zhang

    2012-06-01

    Full Text Available A versatile capacitive tactile sensor based on transparent flexible materials is developed in a simple and low-cost fabrication process. The sensor shows an excellent sensitivity (S=2.05 N-1, and is highly sensitive to the load as low as about 3 mN. Moreover, it exhibits a prominent resolution. The excellent device performance is attributed to the creative design of polydimethylsiloxane (PDMS polymer layer, used as the structural material of the sensor, in which each sensing section acting as a sensor unit is a concave square with hemispheric micro-structured PDMS arrays. Meanwhile, other sections without any PDMS arrays serving as perfect natural wall-barriers can make each sensor unit separated effectively.

  13. 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.

  14. A tactile sensing element based on a hetero-core optical fiber for force measurement and texture detection

    Science.gov (United States)

    Yamazaki, Hiroshi; Koyama, Yuya; Watanabe, Kazuhiro

    2014-05-01

    Tactile sensing technology can measure a given property of an object through physical contact between a sensing element and the object. Various tactile sensing techniques have been developed for several applications such as intelligent robots, tactile interface, medical support and nursing care support. A desirable tactile sensing element for supporting human daily life can be embedded in the soft material with high sensitivity and accuracy in order to prevent from damaging to human or object physically. This report describes a new tactile sensing element. Hetero-core optical fibers have high sensitivity of macro-bending at local sensor portion and temperature independency, including advantages of optical fiber itself; thin size, light weight, flexible transmission line, and immunity to electro-magnetic interference. The proposed tactile sensing element could detect textures of touched objects through the optical loss caused by the force applied to the sensing element. The characteristics of the sensing element have been evaluated, in which the sensing element has the monotonic and non-linear sensitivity against the normal force ranged from 0 to 5 N with lower accuracy than 0.25 dB. Additionally, texture detection have been successfully demonstrated in which small surface figures of 0.1 mm in height were detected with spatial resolution of 0.4 mm.

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

    Science.gov (United States)

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

    2013-07-01

    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.

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

    International Nuclear Information System (INIS)

    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)

  17. 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...

  18. Theta burst stimulation of the dorsolateral prefrontal cortex disrupts attention-based modulation of tactile stimuli at early stages of somatosensory processing

    OpenAIRE

    D. A E Bolton

    2010-01-01

    Damage to the dorsolateral prefrontal cortex (DLPFC) impairs gating of irrelevant sensory information at early cortical processing stages. We investigated how transient inhibition of DLPFC impacts early event-related potentials (ERPs) arising from relevant or irrelevant vibrotactile stimuli to the fingertips. Specifically, we hypothesized that suppression of DLPFC using continuous theta burst stimulation (cTBS) would result in a reduction of attention-based modulation of tactile ERPs at parie...

  19. Postural destabilization induced by trunk extensor muscles fatigue is suppressed by use of a plantar pressure-based electro-tactile biofeedback.

    OpenAIRE

    Vuillerme, Nicolas; Pinsault, Nicolas; Chenu, Olivier; Fleury, Anthony; Payan, Yohan; Demongeot, Jacques

    2008-01-01

    Separate studies have reported that postural control during quiet standing could be (1) impaired with muscle fatigue localized at the lower back, and (2) improved through the use of plantar pressure-based electro-tactile biofeedback, under normal neuromuscular state. The aim of this experiment was to investigate whether this biofeedback could reduce postural destabilization induced by trunk extensor muscles. Ten healthy adults were asked to stand as immobile as possible in four experimental c...

  20. 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)

    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)

  1. 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.

  2. Development of a flexible three-axis tactile sensor based on screen-printed carbon nanotube-polymer composite

    International Nuclear Information System (INIS)

    A flexible, three-axis carbon nanotube (CNT)–polymer composite-based tactile sensor is presented. The proposed sensor consists of a flexible substrate, four sensing cells, and a bump structure. A CNT–polydimethylsiloxane (PDMS) composite is produced by a solvent evaporation method, and thus, the CNTs are well-dispersed within the PDMS matrix. The composite is directly patterned onto a flexible substrate using a screen printing technique to fabricate a sensor with four sensing cells. When a force is applied on the bump, the magnitude and direction of force could be detected by comparing the changes in electrical resistance of each sensing cell caused by the piezoresistive effect of the composite. The experimentally verified sensing characteristics of the fabricated sensor exhibit a linear relationship between the resistance change and the applied force, and the measured sensitivities of the sensor for the normal and shear forces are 6.67 and 86.7%/N for forces up to 2.0 and 0.5 N, respectively. Experiments to verify the load-sensing repeatability show a maximum 2.00% deviation of the resistance change within the tested force range. (paper)

  3. Tactile Displays with Parallel Mechanism

    OpenAIRE

    Kyung, Ki-Uk; Kwon, Dong-Soo

    2008-01-01

    This chapter deals with tactile displays and their mechanisms. We briefly reviewed research history of mechanical type tactile displays and their parallel arrangement. And this chapter mainly describes two systems including tactile displays. The 5x6 pin arrayed tactile display with parallel arrangement of piezoelectric bimorphs has been described in the section 3. The tactile display has been embedded into a mouse device and the performance of the device has been verified from pattern display...

  4. 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.

  5. Tactile imaging of palpable breast cancer

    Science.gov (United States)

    Srikanchana, Rujirutana; Wang, Yue J.; Freedman, Matthew T.; Nguyen, Charles C.

    2002-05-01

    This paper presents the development of a prototype Tactile Mapping Device (TMD) system comprised mainly of a tactile sensor array probe (TSAP), a 3-D camera, and a force/torque sensor, which can provide the means to produce tactile maps of the breast lumps during a breast palpation. Focusing on the key tactile topology features for breast palpation such as spatial location, size/shape of the detected lesion, and the force levels used to demonstrate the palpable abnormalities, these maps can record the results of clinical breast examination with a set of pressure distribution profiles and force sensor measurements due to detected lesion. By combining the knowledge of vision based, neural networks and tactile sensing technology; the TMD is integrated for the investigation of soft tissue interaction with tactile/force sensor, where the hard inclusion (breast cancer) can be characterized through neural network learning capability, instead of using simplified complex biomechanics model with many heuristic assumptions. These maps will serve as an objective documentation of palpable lesions for future comparative examinations. Preliminary results of simulated experiments and limited pre-clinical evaluations of the TMD prototype have tested this hypothesis and provided solid promising data showing the feasibility of the TMD in real clinical applications.

  6. 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.

  7. 机器人指端应变式触觉传感器%The Robotic Fingertip Tactile Sensor Based on Strain-gauge

    Institute of Scientific and Technical Information of China (English)

    戴士杰; 岳宏; 李慨; 李铁军

    2001-01-01

    叙述了机器人指端应变式触觉传感器的原理、分类和发展,介绍几种典型 的机器人指端应变式触觉传感器,同时提出一种新型的机器人指端应变式触觉传 感器,并对其工作原理进行详细说明.在传感器结构设计中采用合理结构,使被 抓物体的横截面尺寸不受弹性薄板薄板尺寸限制;当超过测量范围时,保证金属 薄板不受破坏,同时实现了柔顺抓握.%The principle、classification and development of robotic fin gertip tactile sensor which use strain-gauge is discussed in details. Several typical robotic fingertip tactile sensors based on strain-gaug e is introduced, meanwhile a new kind robotic fingertip tactile sensor based on strain-gauge is presented, and its work principle is explain ed thoroughly.Using proper construction,the size of the object's cros s section,which is grasped bu the gripper, isn't limited by the size o f the taetile thin metal plate; if the object overweight,then the thin metal plate is insured against damage,meauwhile,the more stable and c ompliant grasp can be realized

  8. FFT-based digital tactile vocoder system for real-time use.

    Science.gov (United States)

    Ozdamar, O; Lopez, C N; Oller, D K; Eilers, R E; Miskiel, E; Lynch, M P

    1992-03-01

    A microprocessor-based real-time digital vibrotactile vocoder system has been developed to train the deaf and for artificial hearing research. The system is composed of a microcomputer module with a digital signal processor, interface units and an attenuator/driver circuit. Live or digitised (stored or synthetic) speech is presented to the skin spectrally through a belt housing eight or 16 vibrators. Speech is processed in real time using a fast Fourier transform. The system is also capable of presenting any arbitrary spatiotemporal pattern on the skin for artificial hearing experiments. A preliminary experiment with a deaf subject indicates that the system is potentially an effective device for artificial hearing. PMID:1453787

  9. Preliminary evaluation of the tactile feedback system based on artificial skin and electrotactile stimulation.

    Science.gov (United States)

    Franceschi, M; Seminara, L; Pinna, L; Dosen, S; Farina, D; Valle, M

    2015-08-01

    This research is motivated by the need of integrating cutaneous sensing into a prosthetic device, enabling a bidirectional communication between the amputee and the prosthetic limb. An electronic skin based on piezoelectric polymer sensors transduces mechanical contact into electrical response which is conveyed to the human subject by electrotactile stimulation. Rectangular electrode arrays are placed on each patient's forearm and experiments are conducted on five different subjects to determine how well the orientation, position and direction of single lines are recognized. Overall, subjects discriminate the different touch modalities with acceptable success rates. In particular, the direction is identified at best and longitudinal lines on the patient's skin are recognized with the highest success rates. These preliminary results assess the feasibility of the artificial skin - electrostimulation system for prosthetic applications. PMID:26737307

  10. Tactile Sensing System Based on Arrays of Graphene Woven Microfabrics: Electromechanical Behavior and Electronic Skin Application.

    Science.gov (United States)

    Yang, Tingting; Wang, Wen; Zhang, Hongze; Li, Xinming; Shi, Jidong; He, Yijia; Zheng, Quan-shui; Li, Zhihong; Zhu, Hongwei

    2015-11-24

    Nanomaterials serve as promising candidates for strain sensing due to unique electromechanical properties by appropriately assembling and tailoring their configurations. Through the crisscross interlacing of graphene microribbons in an over-and-under fashion, the obtained graphene woven fabric (GWF) indicates a good trade-off between sensitivity and stretchability compared with those in previous studies. In this work, the function of woven fabrics for highly sensitive strain sensing is investigated, although network configuration is always a strategy to retain resistance stability. The experimental and simulation results indicate that the ultrahigh mechanosensitivity with gauge factors of 500 under 2% strain is attributed to the macro-woven-fabric geometrical conformation of graphene, which induces a large interfacial resistance between the interlaced ribbons and the formation of microscale-controllable, locally oriented zigzag cracks near the crossover location, both of which have a synergistic effect on improving sensitivity. Meanwhile, the stretchability of the GWF could be tailored to as high as over 40% strain by adjusting graphene growth parameters and adopting oblique angle direction stretching simultaneously. We also demonstrate that sensors based on GWFs are applicable to human motion detection, sound signal acquisition, and spatially resolved monitoring of external stress distribution. PMID:26468735

  11. Development of flexible tactile sensors for hexapod robots

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  12. Optimizing the tactile display of physiological information: vibro-tactile vs. electro-tactile stimulation, and forearm or wrist location.

    Science.gov (United States)

    Ng, G; Barralon, P; Dumont, G; Schwarz, S K W; Ansermino, J M

    2007-01-01

    Anesthesiologists use physiological data monitoring systems with visual and auditory displays of information to monitor patients in the operating room (OR). The efficacy of visual-audio systems may impose an increase in patient risk when the demand for constant switching of attention between the patient and the visual monitoring system is high. This is evidenced by auditory alarms frequently being neglected in a noisy OR environment. Hence, the use of a complementary patient data monitoring system, which utilizes other sensory modalities, could be of great value. In this paper, we describe a series of experiments designed to determine the performances of a tactile display that could be used to convey patient's physiological information to the attending anesthesiologist. We tested both vibro-tactile and electro-tactile display prototypes in their ability to convey information using an alert scheme of four distinct tactile stimuli. Using pseudo-clinical data, the display was designed, for example, to provide an alert when a change in the monitored heart rate occurred. Based on previous research in human physiology and psychophysics, we selected the forearm and wrist of the user's non-dominant hand as the stimulation site. In our study of 30 subjects, we evaluated the response time and accuracy of tactile pattern recognition to compare (1) the performance of a vibro-tactile display on the forearm (VF) and an electro-tactile display on the forearm (EF), and (2) the localization of stimulation between the forearm (VF) and a vibro-tactile display on the wrist (VW). A post-study questionnaire was completed by each subject to assess the comfort and usability of the three prototypes. We found that both VF and VW were superior to the EF in both accuracy and comfort and, that there were no differences between the wrist and the forearm. In conclusion, the tactile-display prototypes designed to alert the clinician of adverse changes in a patient's physiological state

  13. 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...

  14. Tactile Navigation Display

    NARCIS (Netherlands)

    Erp, J.B.F. van

    2001-01-01

    The use of the tactile modality is not common in Human Computer Interaction. However, there may be good reasons to do so. For example in situations in which the visual sense is restricted (e.g., in virtual environments lacking a wide field of view, or for the visually handicapped persons), or overlo

  15. Novel high resolution tactile robotic fingertips

    DEFF Research Database (Denmark)

    Drimus, Alin; Jankovics, Vince; Gorsic, Matija; Mátéfi-Tempfli, Stefan

    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. 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.

  17. Tactile perception during action observation.

    Science.gov (United States)

    Vastano, Roberta; Inuggi, Alberto; Vargas, Claudia D; Baud-Bovy, Gabriel; Jacono, Marco; Pozzo, Thierry

    2016-09-01

    It has been suggested that tactile perception becomes less acute during movement to optimize motor control and to prevent an overload of afferent information generated during action. This empirical phenomenon, known as "tactile gating effect," has been associated with mechanisms of sensory feedback prediction. However, less attention has been given to the tactile attenuation effect during the observation of an action. The aim of this study was to investigate whether and how the observation of a goal-directed action influences tactile perception as during overt action. In a first experiment, we recorded vocal reaction times (RTs) of participants to tactile stimulations during the observation of a reach-to-grasp action. The stimulations were delivered on different body parts that could be either congruent or incongruent with the observed effector (the right hand and the right leg, respectively). The tactile stimulation was contrasted with a no body-related stimulation (an auditory beep). We found increased RTs for tactile congruent stimuli compared to both tactile incongruent and auditory stimuli. This effect was reported only during the observation of the reaching phase, whereas RTs were not modulated during the grasping phase. A tactile two-alternative forced-choice (2AFC) discrimination task was then conducted in order to quantify the changes in tactile sensitivity during the observation of the same goal-directed actions. In agreement with the first experiment, the tactile perceived intensity was reduced only during the reaching phase. These results suggest that tactile processing during action observation relies on a process similar to that occurring during action execution. PMID:27161552

  18. Tactile neural mechanisms in monotremes.

    Science.gov (United States)

    Rowe, M J; Mahns, D A; Bohringer, R C; Ashwell, K W S; Sahai, V

    2003-12-01

    Monotremes, perhaps more than any other order of mammals, display an enormous behavioural reliance upon the tactile senses. In the platypus, Ornithorhynchus anatinus, this is manifest most strikingly in the special importance of the bill as a peripheral sensory organ, an importance confirmed by electrophysiological mapping that reveals a vast area of the cerebral cortex allocated to the processing of tactile inputs from the bill. Although behavioural evidence in the echidna, Tachyglossus aculeatus, suggests a similar prominence for tactile inputs from the snout, there is also a great reliance upon the distal limbs for digging and burrowing activity, pointing to the importance of tactile information from these regions for the echidna. In recent studies, we have investigated the peripheral tactile neural mechanisms in the forepaw of the echidna to establish the extent of correspondence or divergence that has emerged over the widely different evolutionary paths taken by monotreme and placental mammals. Electrophysiological recordings were made from single tactile sensory nerve fibres isolated in fine strands of the median or ulnar nerves of the forearm. Controlled tactile stimuli applied to the forepaw glabrous skin permitted an initial classification of tactile sensory fibres into two broad divisions, according to their responses to static skin displacement. One displayed slowly adapting (SA) response properties, while the other showed a selective sensitivity to the dynamic components of the skin displacement. These purely dynamically-sensitive tactile fibres could be subdivided according to vibrotactile sensitivity and receptive field characteristics into a rapidly adapting (RA) class, sensitive to low frequency (tactile sensitivity of the three principal fibre classes and their individual coding characteristics, determined by

  19. Meet our Neighbours - a tactile experience

    Science.gov (United States)

    Canas, L.; Lobo Correia, A.

    2013-09-01

    Planetary science is a key field in astronomy that draws lots of attention and that engages large amounts of enthusiasts. On its essence, it is a visual science and the current resources and activities for the inclusion of visually impaired children, although increasing, are still costly and somewhat scarce. Therefore there is a paramount need to develop more low cost resources in order to provide experiences that can reach all, even the more socially deprived communities. "Meet our neighbours!-a tactile experience", plans to promote and provide inclusion activities for visually impaired children and their non-visually impaired peers through the use of astronomy hands-on low cost activities. Is aimed for children from the ages of 6 to 12 years old and produce data set 13 tactile images of the main objects of the Solar System that can be used in schools, science centres and outreach associations. Accessing several common problems through tactile resources, with this project we present ways to successfully provide low cost solutions (avoiding the expensive tactile printing costs), promote inclusion and interactive hands-on activities for visually impaired children and their non-visually impaired peers and create dynamic interactions based on oral knowledge transmission between them. Here we describe the process of implementing such initiative near target communities: establishing a bridge between scientists, children and teachers. The struggles and challenges perceived during the project and the enrichment experience of engaging astronomy with these specific groups, broadening horizons in an overall experience accessible to all.

  20. 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.

  1. The Design of Flexible Tactile Sensor Based on EIT%基于EIT技术的柔性触觉传感器的设计

    Institute of Scientific and Technical Information of China (English)

    程文芳; 王晓杰; 董帅

    2016-01-01

    The rapid development of robot technology has led to new applications of soft sensors for robotic sensitive skin. In this paper we present a study on the design of flexible tactile sensor based on the piezoresitivity of a new conductive polymer which has been developed by ourselves. The conductive polymer is made by blending PDMS (polydimethylsiloxane,polydimethylsiloxane)with a small amount of multi-walled carbon nanotubes(MWCNTs) which has a high sensitivity in resistance-pressure response. The Electrical Impedance Tomography(EIT)is used to create the flexible tactile sensor. The peripheral hardware circuits based on EIT are designed and manufactured. The data obtained from hardware circuits is processed by computer. The finite element modeling and image recon⁃structue has been performed with a toolkit called EIDORS. The experiment has been carried out to successfully identify the positions of the targets in 1~3 goals when touching on the sensor surface.%随着机器人技术的日益发展,柔性传感器在机器人皮肤上的应用也得到了新的发展。本文提出并研究了一种基于导电聚合物压敏电阻效应的柔性触觉传感器的设计,使用由聚二甲基硅氧烷PDMS(Poly Di Methyl Siloxane)和多壁碳纳米管(MWCNTs)混合而成的导电橡胶作为传感器主体,运用EIT(Electrical Impedance Tomography)技术,设计并制作了本系统的硬件电路,并用其检测、传输导电橡胶的边缘电势数据。最后在计算机中应用工具包EIDORS进行有限元模型和图像重构技术,有效且直观的将导电橡胶上的受力位置表现出来。实验对1~3个目标分别进行了成像,证明了本设计的可行性。

  2. A tactile sensor using a conductive graphene-sponge composite

    Science.gov (United States)

    Chun, Sungwoo; Hong, Ahyoung; Choi, Yeonhoi; Ha, Chunho; Park, Wanjun

    2016-04-01

    For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor.For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00774k

  3. 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.

  4. Phalange Tactile Load Cell

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  5. Tactile Data Entry System Project

    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. Tactile Data Entry for Extravehicular Activity

    Science.gov (United States)

    Adams, Richard J.; Olowin, Aaron B.; Hannaford, Blake; Sands, O Scott

    2012-01-01

    In the task-saturated environment of extravehicular activity (EVA), an astronaut's ability to leverage suit-integrated information systems is limited by a lack of options for data entry. In particular, bulky gloves inhibit the ability to interact with standard computing interfaces such as a mouse or keyboard. This paper presents the results of a preliminary investigation into a system that permits the space suit gloves themselves to be used as data entry devices. Hand motion tracking is combined with simple finger gesture recognition to enable use of a virtual keyboard, while tactile feedback provides touch-based context to the graphical user interface (GUI) and positive confirmation of keystroke events. In human subject trials, conducted with twenty participants using a prototype system, participants entered text significantly faster with tactile feedback than without (p = 0.02). The results support incorporation of vibrotactile information in a future system that will enable full touch typing and general mouse interactions using instrumented EVA gloves.

  7. 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.

  8. Tactile Stimulation and Consumer Response.

    OpenAIRE

    Hornik, Jacob

    1992-01-01

    Tactile behavior is a basic communication form as well as an expression of interpersonal involvement. This article presents three studies offering evidence for the positive role of casual interpersonal touch on consumer behavior. More specifically, it provides initial support for the view that tactile stimulation in various consumer behavior situations enhances the positive feeling for and evaluation of both the external stimuli and the touching source. Further, customers touched by a request...

  9. Airborne Ultrasonic Tactile Display BCI

    OpenAIRE

    Hamada, Katsuhiko; Mori, Hiromu; Shinoda, Hiroyuki; Rutkowski, Tomasz M.

    2015-01-01

    This chapter presents results of our project, which studied whether contactless and airborne ultrasonic tactile display (AUTD) stimuli delivered to a user's palms could serve as a platform for a brain computer interface (BCI) paradigm. We used six palm positions to evoke combined somatosensory brain responses to implement a novel contactless tactile BCI. This achievement was awarded the top prize in the Annual BCI Research Award 2014 competition. This chapter also presents a comparison with a...

  10. Laser application on haptics: Tactile stiffness measurement

    Science.gov (United States)

    Scalise, L.; Memeo, M.; Cannella, F.; Valente, M.; Caldwell, D. G.; Tomasini, E. P.

    2012-06-01

    There is a great interest in exploring the proprieties of the sense of the touch, its detailed knowledge in fact is a key issue in the area of robotics, haptics and human-machine interaction. In this paper, the authors focus their attention on a novel measurement method for the assessment of the tactile stiffness based on a original test rig; tactile stiffness is defined as the ratio between force, exerted by the finger, and the displacement of the finger tip operated during the test. To reach this scope, the paper describes a specific experimental test-rig used for the evaluation of subject tactile sensitivity, where finger force applied during tests as well as displacement and velocity of displacement, operated by the subject under investigation, are measured. Results show that tactile stiffness is linear respect to stimuli spatial difference (which is proportional to the difficulty to detect the variation of them). In particular, it has been possible to relate the force and displacement measured during the tests. The relationship between the response of the subject to the grating, velocity and force is determined. These results permit to carry out the further experimental tests on the same subject avoiding the use of a load cell and therefore simplifying the measurement test rig and data post-processing. Indeed, the first aspect (use of a load cell) can be relevant, because the grating positions are different, requiring a specific re-calibration and setting before each trial; while the second aspect allows simplify the test rig complexity and the processing algorithm.

  11. Spatial attention modulates tactile change detection

    OpenAIRE

    Van Hulle, Lore; Van Damme, Stefaan; Spence, Charles; Crombez, Geert; Gallace, Alberto

    2013-01-01

    People often fail to detect changes between successively presented tactile patterns, a phenomenon known as tactile change blindness. In this study, we investigated whether changes introduced to tactile patterns are detected better when a participant's attention is focused on the location where the change occurs. Across two experiments, participants (N = 55) were instructed to detect changes between two consecutively presented tactile patterns. In half of the trials, the stimulated body sites ...

  12. Microfabricated Tactile Sensors for Biomedical Applications: A Review

    Directory of Open Access Journals (Sweden)

    Paola Saccomandi

    2014-11-01

    Full Text Available During the last decades, tactile sensors based on different sensing principles have been developed due to the growing interest in robotics and, mainly, in medical applications. Several technological solutions have been employed to design tactile sensors; in particular, solutions based on microfabrication present several attractive features. Microfabrication technologies allow for developing miniaturized sensors with good performance in terms of metrological properties (e.g., accuracy, sensitivity, low power consumption, and frequency response. Small size and good metrological properties heighten the potential role of tactile sensors in medicine, making them especially attractive to be integrated in smart interfaces and microsurgical tools. This paper provides an overview of microfabricated tactile sensors, focusing on the mean principles of sensing, i.e., piezoresistive, piezoelectric and capacitive sensors. These sensors are employed for measuring contact properties, in particular force and pressure, in three main medical fields, i.e., prosthetics and artificial skin, minimal access surgery and smart interfaces for biomechanical analysis. The working principles and the metrological properties of the most promising tactile, microfabricated sensors are analyzed, together with their application in medicine. Finally, the new emerging technologies in these fields are briefly described.

  13. Early Intervention with a Parent-Delivered Massage Protocol Directed at Tactile Abnormalities Decreases Severity of Autism and Improves Child-to-Parent Interactions: A Replication Study

    OpenAIRE

    Silva, Louisa M. T.; Mark Schalock; Gabrielsen, Kristen R.; Budden, Sarojini S.; Martha Buenrostro; Gretchen Horton

    2015-01-01

    Tactile abnormalities are severe and universal in preschool children with autism. They respond well to treatment with a daily massage protocol directed at tactile abnormalities (QST massage for autism). Treatment is based on a model for autism proposing that tactile impairment poses a barrier to development. Two previous randomized controlled trials evaluating five months of massage treatment reported improvement of behavior, social/communication skills, and tactile and other sensory symptoms...

  14. 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.

  15. Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

    CERN Document Server

    Salehi, Saba; Ge, Shuzhi Sam; 10.3390/s110908626

    2011-01-01

    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 \\times 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 Na\\"ive Bayes (NB), Artificial Neural Networks (ANN), and Support Vector Machines (SVM) were implemented and compared ...

  16. Toward Low-Cost Highly Portable Tactile Displays with Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    R. Velázquez

    2007-01-01

    Full Text Available This paper presents a new concept of low-cost, high-resolution, lightweight, compact and highly portable tactile display. The prototype consists of an array of 8 × 8 upward/downward independent moveable pins based on shape memory alloy (SMA technology. Each tactile actuator consists of an antagonist arranged pair of miniature NiTi SMA helical springs capable of developing a 300 mN pull force at 1.5 Hz bandwidth by using simple forced-air convection. The proposed concept allows the development of 200 g weight tactile instruments of compact dimensions which can be easily carried by a visually disabled user. A detailed technical description of the SMA active element, tactile actuator and tactile display is presented and discussed. Preliminary perceptual results confirm the effectiveness of the display on information transmission.

  17. 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 ...

  18. P(VDF-TrFE Polymer-Based Thin Films Deposited on Stainless Steel Substrates Treated Using Water Dissociation for Flexible Tactile Sensor Development

    Directory of Open Access Journals (Sweden)

    Hong-Jie Tseng

    2013-10-01

    Full Text Available In this work, deionized (DI water dissociation was used to treat and change the contact angle of the surface of stainless steel substrates followed by the spin coating of P(VDF-TrFE material for the fabrication of tactile sensors. The contact angle of the stainless steel surface decreased 14° at −30 V treatment; thus, the adhesion strength between the P(VDF-TrFE thin film and the stainless steel substrate increased by 90%. Although the adhesion strength was increased at negative voltage treatment, it is observed that the crystallinity value of the P(VDF-TrFE thin film declined to 37% at −60 V. In addition, the remanent polarization value of the P(VDF-TrFE thin film declined from 5.6 mC/cm2 to 4.61 mC/cm2 for treatment voltages between −5 V and −60 V. A maximum value of approximately 1000 KV/cm of the coercive field value was obtained with the treatment at −15 V. The d33 value was approximately −10.7 pC/N for the substrate treated at 0 V and reached a minimum of −5 pC/N for treatment at −60 V. By using the P(VDF-TrFE thin-film as the sensing material for tactile sensors, human pulse measurements were obtained from areas including the carotid, brachial, ankle, radial artery, and apical regions. In addition, the tactile sensor is suitable for monitoring the Cun, Guan, and Chi acupoints located at the radial artery region in Traditional Chinese Medicine (TCM. Waveform measurements of the Cun, Guan, and Chi acupoints are crucial because, in TCM, the various waveforms provided information regarding the health conditions of organs.

  19. 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 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...

  20. 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.

  1. Studying tactile sensitivity - population approach

    OpenAIRE

    Kozłowska, Agnieszka

    1998-01-01

    The purpose of this study was to investigate the basic characteristics of threshold tactile sensitivity in man. The study involved the examination of over 1500 people aged from 7 to 85 years, including 300 adult subjects aged over 21 years. 55% of the population under study were females. Digital pulps of the subjects were examined with the Semmes-Weinstein monofilaments aesthesiometer. The variability range of touch sensation was determined and the mean value and standard deviatio...

  2. Tactile Perception - Role of Physical Properties

    OpenAIRE

    Skedung, Lisa

    2010-01-01

    The aim of this thesis is to interconnect human tactile perception with various physical properties of materials. Tactile perception necessitates contact and relative motion between the skin and the surfaces of interest. This implies that properties such as friction and surface roughness ought to be important physical properties for tactile sensing. In this work, a method to measure friction between human fingers and surfaces is presented. This method is believed to best represent friction in...

  3. Flexible Tactile Sensor Using Polyurethane Thin Film

    OpenAIRE

    Seiji Aoyagi; Tomokazu Takahashi; Masato Suzuki

    2012-01-01

    A novel capacitive tactile sensor using a polyurethane thin film is proposed in this paper. In previous studies, capacitive tactile sensors generally had an air gap between two electrodes in order to enhance the sensitivity. In this study, there is only polyurethane thin film and no air gap between the electrodes. The sensitivity of this sensor is higher than the previous capacitive tactile sensors because the polyurethane is a fairly flexible elastomer and the film is very thin (about 1 µm)....

  4. Do "mudsplashes" induce tactile change blindness?

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2007-05-01

    The phenomenon of change blindness (the surprising inability of people to correctly perceive changes between consecutively presented displays), primarily reported in vision, has recently been shown to occur for positional changes presented in tactile displays as well. Here, we studied people's ability to detect changes in the number of tactile stimuli in successively presented displays composed of one to three stimuli distributed over the body surface. In Experiment 1, a tactile mask consisting of the simultaneous activation of all seven possible tactile stimulators was sometimes presented between the two to-be-discriminated tactile displays. In Experiment 2, a "mudsplash" paradigm was used, with a brief irrelevant tactile distractor presented at the moment of change of the tactile display. Change blindness was demonstrated in both experiments, thus showing that the failure to detect tactile change is not necessarily related to (1) the physical disruption between consecutive events, (2) the effect of masking covering the location of the change, or (3) the erasure or resetting of the information contained within an internal representation of the tactile display. These results are interpreted in terms of a limitation in the number of spatial locations/events that can be consciously accessed at any one time. This limitation appears to constrain change-detection performance, no matter the sensory modality in which the stimuli are presented. PMID:17727101

  5. 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.

  6. 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.

  7. Tactile object exploration using cursor navigation sensors

    DEFF Research Database (Denmark)

    Kraft, Dirk; Bierbaum, Alexander; Kjaergaard, Morten; Ratkevicius, Jurgis; Kjær-Nielsen, Anders; Ryberg, Charlotte; Petersen, Henrik Gordon; Asfour, Tamim; Dillmann, Ruediger; Krüger, Norbert

    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 of this...

  8. Tactile information presentation : Navigating in virtual environments

    NARCIS (Netherlands)

    Erp, J.B.F. van

    2000-01-01

    Even state–of–the–art virtual environments (VEs) are often restricted to the visual modality only. The use of the tactile modality might not only result in an increased immersion, but may also enhance performance. An example that will be discussed in this paper is the use of the tactile channel to p

  9. Slime mould tactile sensor

    OpenAIRE

    Adamatzky, Andrew

    2013-01-01

    Slime mould P. polycephalum is a single cells visible by unaided eye. The cells shows a wide spectrum of intelligent behaviour. By interpreting the behaviour in terms of computation one can make a slime mould based computing device. The Physarum computers are capable to solve a range of tasks of computational geometry, optimisation and logic. Physarum computers designed so far lack of localised inputs. Commonly used inputs --- illumination and chemo-attractants and -repellents --- usually act...

  10. 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...... use 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...

  11. Survey of Visual and Force/Tactile Control of Robots for Physical Interaction in Spain

    OpenAIRE

    Fernando Torres; Jorge Pomares; Garcia, Gabriel J.; Corrales, Juan A.

    2009-01-01

    Sensors provide robotic systems with the information required to perceive the changes that happen in unstructured environments and modify their actions accordingly. The robotic controllers which process and analyze this sensory information are usually based on three types of sensors (visual, force/torque and tactile) which identify the most widespread robotic control strategies: visual servoing control, force control and tactile control. This paper presents a detailed review on the sensor arc...

  12. Three realizations and comparison of hardware for piezoresistive tactile sensors.

    Science.gov (United States)

    Vidal-Verdú, Fernando; Oballe-Peinado, Óscar; Sánchez-Durán, José A; Castellanos-Ramos, Julián; Navas-González, Rafael

    2011-01-01

    Tactile sensors are basically arrays of force sensors that are intended to emulate the skin in applications such as assistive robotics. Local electronics are usually implemented to reduce errors and interference caused by long wires. Realizations based on standard microcontrollers, Programmable Systems on Chip (PSoCs) and Field Programmable Gate Arrays (FPGAs) have been proposed by the authors for the case of piezoresistive tactile sensors. The solution employing FPGAs is especially relevant since their performance is closer to that of Application Specific Integrated Circuits (ASICs) than that of the other devices. This paper presents an implementation of such an idea for a specific sensor. For the purpose of comparison, the circuitry based on the other devices is also made for the same sensor. This paper discusses the implementation issues, provides details regarding the design of the hardware based on the three devices and compares them. PMID:22163797

  13. Three Realizations and Comparison of Hardware for Piezoresistive Tactile Sensors

    Directory of Open Access Journals (Sweden)

    Rafael Navas-González

    2011-03-01

    Full Text Available Tactile sensors are basically arrays of force sensors that are intended to emulate the skin in applications such as assistive robotics. Local electronics are usually implemented to reduce errors and interference caused by long wires. Realizations based on standard microcontrollers, Programmable Systems on Chip (PSoCs and Field Programmable Gate Arrays (FPGAs have been proposed by the authors for the case of piezoresistive tactile sensors. The solution employing FPGAs is especially relevant since their performance is closer to that of Application Specific Integrated Circuits (ASICs than that of the other devices. This paper presents an implementation of such an idea for a specific sensor. For the purpose of comparison, the circuitry based on the other devices is also made for the same sensor. This paper discusses the implementation issues, provides details regarding the design of the hardware based on the three devices and compares them.

  14. Follicular DEAs for two-way tactile communication

    Science.gov (United States)

    Knoop, Lars E.; Rossiter, Jonathan; Assaf, Tareq

    2015-04-01

    Follicular structures in skin combine sensing and actuation in a soft and compliant continuous surface. We have developed a tactile display device inspired by this structure, using a Dielectric Elastomer Actuator (DEA). DEAs allow for combined sensing and actuation, making possible two-way tactile communication between the user and the device. The device can obtain tactile information about the environment, or a user touching it, and it can also present tactile information to the user. We characterise the sensing properties of the tactile display device, and perform classification of tactile stimuli. We demonstrate two-way tactile interaction between a user and the device.

  15. A New Approach in Design and Operating Principle of Silicone Tactile Sensor

    Directory of Open Access Journals (Sweden)

    Bakri Ali

    2010-01-01

    Full Text Available Problem statement: Research and development in tactile sensor are escalating due to the fact that advanced robot needs to interact with surrounding environments which is very complex, dynamic, uncontrolled and difficult to perceive reliably. Recent research has been focusing in development of new tactile sensor that takes advantage of advances in materials, Micro-Electromechanical Systems (MEMS and semiconductor technology. To date, several basic sensing principles are commonly used in tactile sensor such as capacitive sensor, piezoelectric sensor, inductive sensor, opto-electrical and piezo-resistive sensor. However they are still lack of sensitivity and low dynamic range in sensing the changes of forces in 3 axes and not durable enough to perform in various working environments. Approach: Three different designs of optical tactile sensor was proposed and analyzed. The overall design of the test-rig of the system was presented. The working principle was based on the deformation of the silicone tactile sensor. The deformation image will be transferred through high quality medical fiberscope and will be recorded using a CCD camera. The image will be stored in a computer for further analysis to relate the image with the given forces. These data can be used to control a robotic gripper so that it can perform gently and precisely like human tactile sensing capability but with greater strength and durability in various working environments. Results: The sensor had been designed and an experimental test rig was developed. Initial experiment was carried out to check the potential of this technique. Based on results, there is almost a linear relationship between the forces and the deformation of the tactile sensor. The amount of deformation is calculated based on the analyzed image data. Conclusion: The results of the experiment gave a convincing idea and provide a ground for further research to enhance this system to be an alternative tactile sensor in

  16. Testing of tactile sensors for space applications

    Science.gov (United States)

    Kogan, Lisa; Weadon, Timothy L.; Evans, Thomas; DeVallance, David B.; Sabolsky, Edward M.

    2015-03-01

    There is a need to integrate tactile sensing into robotic manipulators performing tasks in space environments, including those used to repair satellites. Integration can be achieved by embedding specialized tactile sensors. Reliable and consistent signal interpretation can be obtained by ensuring that sensors with a suitable sensing mechanism are selected based on operational demands, and that materials used within the sensors do not change structurally under vacuum and expected applied pressures, and between temperatures of -80°C to +120°C. The sensors must be able to withstand space environmental conditions and remain adequately sensitive throughout their operating life. Additionally, it is necessary to integrate the sensors into the target system with minimum disturbance while remaining responsive to applied loads. Previous work has been completed to characterize sensors within the selected temperature and pressure ranges. The current work builds on this investigation by embedding these sensors in different geometries and testing the response measured among varying configurations. Embedding material selection was aided by using a dynamic mechanical analyzer (DMA) to determine stress/strain behavior for adhesives and compliant layers used to keep the sensors in place and distribute stresses evenly. Electromechanical characterization of the embedded sensor packages was conducted by using the DMA in tandem with an inductance-capacitance-resistance (LCR) meter. Methods for embedding the sensor packages were developed with the aid of finite element analysis and physical testing to account for specific geometrical constraints. Embedded sensor prototypes were tested within representative models of potential embedding locations to compare final embedded sensor performance.

  17. 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.

  18. Learning effects of piano playing on tactile recognition of sequential stimuli.

    Science.gov (United States)

    Hatta, T; Ejiri, A

    1989-01-01

    To examine the effect of learning experiences of piano playing on a tactile sequential recognition task, two experiments were conducted. In the first experiment, pianists and control subjects were given sequential tactile stimuli and were asked to report the simulated fingers and the order. The pianists showed a left hand superiority and performed better than the control group. In the second experiment, the skilled pianists and the control subjects were given both sequential tactile stimuli and auditory stimuli (unrelated melodies) simultaneously. The sequential stimuli recognition of the skilled pianists was interfered with by the presentation of the unrelated melody, and this tendency was more prominent in their left hand, while the performance of the control subjects was not affected by the presentation of the melody. These results suggest that pianists employed a special strategy, such as transforming tactile stimuli into something like a melody to improve their performance. Based upon these results, effects of learning experiences on hemisphere function were discussed. PMID:2615935

  19. 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. PMID:26737606

  20. 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. PMID:25368587

  1. 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.

  2. 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...

  3. Nano opto-mechanical systems (NOMS) as a proposal for tactile displays

    Science.gov (United States)

    Campo, E. M.; Roig, J.; Roeder, B.; Wenn, D.; Mamojka, B.; Omastova, M.; Terentjev, E. M.; Esteve, J.

    2011-10-01

    For over a decade, special emphasis has been placed in the convergence of different fields of science and technology, in an effort to serve human needs by way of enhancing human capabilities. The convergence of the Nano-Bio-Info-Cogni (NBIC) quartet will provide unique solutions to specific needs. This is the case of, Nano-opto mechanical Systems (NOMS), presented as a solution to tactile perception, both for the visually-impaired and for the general public. NOMS, based on photoactive polymer actuators and devices, is a much sought-after technology. In this scheme, light sources promote mechanical actuation producing a variety of nano-opto mechanical systems such as nano-grippers. In this paper, we will provide a series of specifications that the NOMS team is targeting towards the development of a tactile display using optically-activated smart materials. Indeed, tactile displays remain mainly mechanical, compromising reload speeds and resolution which inhibit 3D tactile representation of web interfaces. We will also discuss how advantageous NOMS tactile displays could be for the general public. Tactile processing based on stimulation delivered through the NOMS tablet, will be tested using neuropsychology methods, in particular event-related brain potentials. Additionally, the NOMS tablet will be instrumental to the development of basic neuroscience research.

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

    International Nuclear Information System (INIS)

    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. (technical note)

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

    OpenAIRE

    Achint Aggarwal; Frank Kirchner

    2014-01-01

    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...

  6. Object Recognition and Localization : the Role of Tactile Sensors

    OpenAIRE

    Aggarwal, Achint

    2015-01-01

    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 thesis 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 Sequential Filter (BRICPSF) is based on an innovat...

  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. Introduction to tactile displays in military environments

    NARCIS (Netherlands)

    Erp, J.B.F. van; Self, B.P.

    2008-01-01

    Challenging situations, such as those encountered by military pilots, are often a major thrust for ergonomic innovation. Examples include the development of advanced, multimodal, and intuitive interface techniques to counteract the danger of visual, auditory, and cognitive overload. Tactile displays

  9. The neural basis of tactile motion perception

    OpenAIRE

    Pei, Yu-Cheng; Sliman J Bensmaia

    2014-01-01

    The manipulation of objects commonly involves motion between object and skin. In this review, we discuss the neural basis of tactile motion perception and its similarities with its visual counterpart. First, much like in vision, the perception of tactile motion relies on the processing of spatiotemporal patterns of activation across populations of sensory receptors. Second, many neurons in primary somatosensory cortex are highly sensitive to motion direction, and the response properties of th...

  10. Tactile Perception : Role of Friction and Texture

    OpenAIRE

    Skedung, Lisa

    2012-01-01

    Tactile perception is considered an important contributor to the overall consumer experience of a product. However, what physical properties that create the specifics of tactile perception, are still not completely understood. This thesis has researched how many dimensions that are required to differentiate the surfaces perceptually, and then tried to explain these dimensions in terms of physical properties, by interconnecting human perception measurements with various physical measurements. ...

  11. Learning tactile skills through curious exploration

    OpenAIRE

    Leo Pape; Calogero Maria Oddo

    2012-01-01

    We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content o...

  12. Scalable, MEMS-enabled, vibrational tactile actuators for high resolution tactile displays

    International Nuclear Information System (INIS)

    The design, fabrication, and characterization of a new type of tactile display for people with blindness or low vision is reported. Each tactile element comprises a piezoelectric extensional actuator that vibrates in plane, with a microfabricated scissor mechanism to convert the in-plane actuations into robust, higher-amplitude, out-of-plane (vertical) vibrations that are sensed with the finger pads. When the tactile elements are formed into a 2D array, information can be conveyed to the user by varying the pattern of vibrations in space and time. Analytical models and finite element analysis were used to design individual tactile elements, which were implemented with PZT actuators and both SU-8 and 3D-printed scissor amplifiers. The measured displacements of these 3 mm × 10 mm, MEMS-enabled tactile elements exceed 10 µm, in agreement with models, with measured forces exceeding 45 mN. The performance of the MEMS-enabled tactile elements is compared with the performance of larger, fully-macroscale tactile elements to demonstrate the scale dependence of the devices. The creation of a 28-element prototype is also reported, and the qualitative user experience with the individual tactile elements and displays is described. (paper)

  13. 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.

  14. Learning tactile skills through curious exploration

    Directory of Open Access Journals (Sweden)

    Leo Pape

    2012-07-01

    Full Text Available We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content of the sensory input signals relative to a learner that aims at representing sensory inputs using fewer and fewer computational resources. We show that, from initially random exploration of its environment, the robotic system autonomously develops a small set of basic motor skills that lead to different kinds of tactile input. Next, the system learns how to exploit the learned motor skills to solve supervised texture classification tasks. Our approach demonstrates the feasibility of autonomous acquisition of tactile skills on physical robotic platforms through curiosity-driven reinforcement learning, overcomes typical difficulties of engineered solutions for active tactile exploration and underactuated control, and provides a basis for studying developmental learning through intrinsic motivation in robots.

  15. Tactile Stimulation Reduces Fear in Fish

    Directory of Open Access Journals (Sweden)

    Annett Schirmer

    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.

  16. 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...

  17. Factors Affecting Traceability of Lines for Tactile Graphics.

    Science.gov (United States)

    Bentzen, Billie Louise; Peck, Alec F.

    1979-01-01

    To facilitate appropriate line choice for tactile graphic displays, 42 visually impaired Ss traced four types of tactile lines in a simple display (without intersections), and in a complex display (having intersections). (Author)

  18. Shear sensitive silicon piezoresistive tactile sensor prototype

    Science.gov (United States)

    Wang, Lin; Beebe, David J.

    1998-09-01

    Shear sensing ability it important in many fields such as robotics, rehabilitation, teleoperation and human computer interfaces. A shear sensitive tactile sensor prototype is developed based on the principles of the piezoresistive effect in silicon, and using microfabrication technology. Analogous to the conventional silicon piezoresistive pressure sensor, piezoresistive resistors embedded in a silicon diaphragm are used to sense stress change. An additional mesa is fabricated on the top of the diaphragm and serves to transform an applied force to a stress. Both the shear and normal components of the force are resolved by measuring the resistance changes of the four resistors placed at the corners of a prism mesa. The prototype is tested both statically and dynamically when a spatial force of 0 - 300 gram is applied. Good linearity (R > 0.98) and high repeatability are observed. In this paper, the force sensing mechanism and force determination approach are described. The fabrication process is presented. The preliminary testing results are presented and discussed.

  19. Millisecond precision spike timing shapes tactile perception.

    Science.gov (United States)

    Mackevicius, Emily L; Best, Matthew D; Saal, Hannes P; Bensmaia, Sliman J

    2012-10-31

    In primates, the sense of touch has traditionally been considered to be a spatial modality, drawing an analogy to the visual system. In this view, stimuli are encoded in spatial patterns of activity over the sheet of receptors embedded in the skin. We propose that the spatial processing mode is complemented by a temporal one. Indeed, the transduction and processing of complex, high-frequency skin vibrations have been shown to play an important role in tactile texture perception, and the frequency composition of vibrations shapes the evoked percept. Mechanoreceptive afferents innervating the glabrous skin exhibit temporal patterning in their responses, but the importance and behavioral relevance of spike timing, particularly for naturalistic stimuli, remains to be elucidated. Based on neurophysiological recordings from Rhesus macaques, we show that spike timing conveys information about the frequency composition of skin vibrations, both for individual afferents and for afferent populations, and that the temporal fidelity varies across afferent class. Furthermore, the perception of skin vibrations, measured in human subjects, is better predicted when spike timing is taken into account, and the resolution that predicts perception best matches the optimal resolution of the respective afferent classes. In light of these results, the peripheral representation of complex skin vibrations draws a powerful analogy with the auditory and vibrissal systems. PMID:23115169

  20. 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.

  1. Irrelevant tactile stimulation biases visual exploration in external coordinates

    OpenAIRE

    Ossandón, José P.; Peter König; Tobias Heed

    2015-01-01

    We evaluated the effect of irrelevant tactile stimulation on humans’ free-viewing behavior during the exploration of complex static scenes. Specifically, we address the questions of (1) whether task-irrelevant tactile stimulation presented to subjects’ hands can guide visual selection during free viewing; (2) whether tactile stimulation can modulate visual exploratory biases that are independent of image content and task goals; and (3) in which reference frame these effects occur. Tactile sti...

  2. 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.

  3. The Cognitive and Neural Correlates of Tactile Memory

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2009-01-01

    Tactile memory systems are involved in the storage and retrieval of information about stimuli that impinge on the body surface and objects that people explore haptically. Here, the authors review the behavioral, neuropsychological, neurophysiological, and neuroimaging research on tactile memory. This body of research reveals that tactile memory…

  4. The effects of negative emotions on sensory perception: Fear but not anger decreases tactile sensitivity

    Directory of Open Access Journals (Sweden)

    Nicholas J Kelley

    2014-08-01

    Full Text Available Emotions and sensory perceptions are closely intertwined. Of the five senses sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances sensory perception, including tactile sensitivity. A competing hypothesis based on research on peripheral psychophysiology predicts that fear should decrease tactile sensitivity. Two experiments that induced negative emotional states and measured two-point discrimination ability found that fear reduces tactile sensitivity relative to anger or a neutral control condition (Studies 1 and 2. These findings did not appear to be driven by participants’ naïve beliefs about the influence of emotions on touch (Study 3. The results represent the first evidence of the causal impact of emotional states on tactile sensitivity, are consistent with prior evidence for the peripheral physiological effects of fear, and offer novel empirical grounds for developing and advancing theories of emotional influences on sensory perception.

  5. 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...... considered “tacit knowledge” and a “tacit experience”. Finally, we conclude that if designers wish to promote change related to sustainability, it is likely that an embodied participatory dialogue that builds on the combination of user experience and tactile sensibility can be further developed into didactic...

  6. Comparative effectiveness of visual/tactile and simplified screening examinations in caries risk assessment.

    Science.gov (United States)

    Disney, J A; Abernathy, J R; Graves, R C; Mauriello, S M; Bohannan, H M; Zack, D D

    1992-12-01

    Central to the development of a model for identifying children at high risk to caries is a clinical evaluation to assess dental status and other conditions potentially useful in caries prediction. Traditionally, this evaluation has been based on a relatively lengthy visual/tactile examination conducted by a dentist. Replacing the dentist examination with a dental auxiliary conducted screening evaluation could lead to reduced time and costs. The 4-yr University of North Carolina Caries Risk Assessment Study involved approximately 5000 schoolchildren initially in Grades 1 and 5 living near Aiken, South Carolina, and Portland, Maine. The effectiveness of caries prediction models using visual/tactile examination data were compared with the same models using simplified screening evaluation data. Results showed sensitivity ranged from 0.57 to 0.61 for the visual/tactile and screening models by site and grade cohort. Specificity for the models ranged from 0.80 to 0.83. None of these differences in sensitivity and specificity between visual/tactile (dentist) and screening (hygienist) models was statistically significant. Findings show that for the prediction of children at high risk to dental caries the clinical evaluation may be conducted with no reduction of precision by using dental hygienist performed screening evaluations rather than dentist conducted visual/tactile examinations. While no cost data were collected, these results imply that costs to future prediction programs could be reduced by using screening evaluations. PMID:1464226

  7. A computational model for estimating tumor margins in complementary tactile and 3D ultrasound images

    Science.gov (United States)

    Shamsil, Arefin; Escoto, Abelardo; Naish, Michael D.; Patel, Rajni V.

    2016-03-01

    Conventional surgical methods are effective for treating lung tumors; however, they impose high trauma and pain to patients. Minimally invasive surgery is a safer alternative as smaller incisions are required to reach the lung; however, it is challenging due to inadequate intraoperative tumor localization. To address this issue, a mechatronic palpation device was developed that incorporates tactile and ultrasound sensors capable of acquiring surface and cross-sectional images of palpated tissue. Initial work focused on tactile image segmentation and fusion of position-tracked tactile images, resulting in a reconstruction of the palpated surface to compute the spatial locations of underlying tumors. This paper presents a computational model capable of analyzing orthogonally-paired tactile and ultrasound images to compute the surface circumference and depth margins of a tumor. The framework also integrates an error compensation technique and an algebraic model to align all of the image pairs and to estimate the tumor depths within the tracked thickness of a palpated tissue. For validation, an ex vivo experimental study was conducted involving the complete palpation of 11 porcine liver tissues injected with iodine-agar tumors of varying sizes and shapes. The resulting tactile and ultrasound images were then processed using the proposed model to compute the tumor margins and compare them to fluoroscopy based physical measurements. The results show a good negative correlation (r = -0.783, p = 0.004) between the tumor surface margins and a good positive correlation (r = 0.743, p = 0.009) between the tumor depth margins.

  8. The attentive homunculus: ERP evidence for somatotopic allocation of attention in tactile search.

    Science.gov (United States)

    Forster, Bettina; Tziraki, Maria; Jones, Alexander

    2016-04-01

    Our brain constantly receives tactile information from the body's surface. We often only become aware of this information when directing our attention towards the body. Here, we report a study investigating the behavioural and neural response when selecting a target amongst distractor vibrations presented simultaneously to several locations either across the hands or body. Comparable visual search studies have revealed the N2pc as the neural correlate of visual selective attention. Analogously, we describe an enhanced negativity contralateral to the tactile target side. This effect is strongest over somatosensory areas and lasts approximately 200ms from the onset of the somatosensory N140 ERP component. Based on these characteristics we named this electrophysiological signature of attentional tactile target selection during tactile search the N140-central-contralateral (N140cc). Furthermore, we present supporting evince that the N140cc reflects attentional enhancement of target rather than suppression of distractor locations; the component was not reliably altered by distractor but rather by target location changes. Taken together, our findings present a novel electrophysiological marker of tactile search and show how attentional selection of touch operates by mainly enhancing task relevant locations within the somatosensory homunculus. PMID:26898371

  9. An Optoelectromechanical Tactile Sensor for Detection of Breast Lumps

    OpenAIRE

    Başdoğan, Çağatay; Ayyıldız, Mehmet; Yıldız, Mustafa Zahid; Güçlü, Burak

    2013-01-01

    We developed a compact tactile imaging (TI) system to guide the clinician or the self-user for noninvasive detection of breast tumors. Our system measures the force distribution based on the difference in stiffness between a palpated object and an abnormality within. The average force resolution, force range, and the spatial resolution of the device are 0.02 N, 0-4 N, and 2.8 mm, respectively. To evaluate the performance of the proposed TI system, compression experiments were performed to mea...

  10. 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

  11. The Scanning of Power Deformation of Tyre Surface by Tactile Piesoresistive sensors

    Directory of Open Access Journals (Sweden)

    Ferdinand Hurta

    2004-01-01

    Full Text Available Our work describes a static non-destructive method of measuring the contact pressures of tyres. The distribution of contact pressures during the contact of the tyre with a solid base represents one of the indicators we use. In this process, it is convenient to use matrix tactile sensors based on piezoresistive method of data collection.

  12. The Scanning of Power Deformation of Tyre Surface by Tactile Piesoresistive sensors

    OpenAIRE

    2004-01-01

    Our work describes a static non-destructive method of measuring the contact pressures of tyres. The distribution of contact pressures during the contact of the tyre with a solid base represents one of the indicators we use. In this process, it is convenient to use matrix tactile sensors based on piezoresistive method of data collection.

  13. Short term memory for tactile stimuli.

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Haggard, Patrick; Spence, Charles

    2008-01-23

    Research has shown that unreported information stored in rapidly decaying visual representations may be accessed more accurately using partial report than using full report procedures (e.g., [Sperling, G., 1960. The information available in brief visual presentations. Psychological Monographs, 74, 1-29.]). In the 3 experiments reported here, we investigated whether unreported information regarding the actual number of tactile stimuli presented in parallel across the body surface can be accessed using a partial report procedure. In Experiment 1, participants had to report the total number of stimuli in a tactile display composed of up to 6 stimuli presented across their body (numerosity task), or else to detect whether or not a tactile stimulus had previously been presented in a position indicated by a visual probe given at a variable delay after offset of a tactile display (i.e., partial report). The results showed that participants correctly reported up to 3 stimuli in the numerosity judgment task, but their performance was significantly better than chance when up to 5 stimuli were presented in the partial report task. This result shows that short-lasting tactile representations can be accessed using partial report procedures similar to those used previously in visual studies. Experiment 2 showed that the duration of these representations (or the time available to consciously access them) depends on the number of stimuli presented in the display (the greater the number of stimuli that are presented, the faster their representation decays). Finally, the results of a third experiment showed that the differences in performance between the numerosity judgment and partial report tasks could not be explained solely in terms of any difference in task difficulty. PMID:18083147

  14. Watching what's coming near increases tactile sensitivity: An experimental investigation.

    Science.gov (United States)

    Van der Biest, Lien; Legrain, Valéry; Paepe, Annick De; Crombez, Geert

    2016-01-15

    During medical examinations, doctors regularly investigate a patient's somatosensory system by approaching the patient with a medical device (e.g. Von Frey hairs, algometer) or with their hands. It is assumed that the obtained results reflect the true capacities of the somatosensory system. However, evidence from crossmodal spatial research suggests that sensory experiences in one modality (e.g. touch) can be influenced by concurrent information from other modalities (e.g. vision), especially near the body (i.e. in peripersonal space). Hence, we hypothesized that seeing someone approaching your body could alter tactile sensitivity in that body-part. In the In Vivo Approaching Object (IVAO) paradigm, participants detected and localized threshold-level vibrotactile stimuli administered on the left of right hand (=tactile targets). In Experiment 1, this was always preceded by the experimenter approaching the same (congruent trials) or the other (incongruent trials) hand with a pen (=visual cue). In Experiment 2, a condition was added in which a point further away from the hands (also left vs. right) was approached. Response Accuracy was calculated for congruent and incongruent trials (Experiment 1 & 2) and compared between the close and far condition (Experiment 2). As expected, Response Accuracy was higher in congruent trials compared to incongruent trials, but only near the body. As a result, evidence was found for a crossmodal interaction effect between visual and tactile information in peripersonal space. These results suggest that somatosensory evaluations-both medical or research-based-may be biased by viewing an object approaching the body. PMID:26475955

  15. 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

  16. A new dynamic tactile display for reconfigurable braille: implementation and tests.

    Science.gov (United States)

    Motto Ros, Paolo; Dante, Vittorio; Mesin, Luca; Petetti, Erminio; Del Giudice, Paolo; Pasero, Eros

    2014-01-01

    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 0.7mm) as well as tunable strength of the pins displacement, and refresh rate up to 50s(-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 solution

  17. Juggling reveals a decisional component to tactile suppression.

    Science.gov (United States)

    Juravle, Georgiana; Spence, Charles

    2011-08-01

    Goal-directed movements are characterized by sensory suppression, that is, by decreased sensitivity to tactile stimuli. In the present study, we investigated tactile suppression during movement using a complex motor task: basic 3-ball juggling. It was hypothesized that a decrease in tactile sensitivity would be observed, together with a shift in participants' response bias while juggling. In a first experiment, participants had to detect a short gap in an otherwise continuous vibratory stimulus, which was delivered to their wrist under conditions of rest or else while juggling. In a second experiment, participants detected a short time gap in a continuous auditory signal, under the same conditions. In a final control experiment performed at rest, participants detected a short time gap in an auditory or tactile signal. In an additional condition, the detection of a gap in tactile stimulation was required under conditions of intramodal tactile interference. Participants were significantly less sensitive to detect a gap in tactile stimulation whilst juggling. Most importantly, these results were paired with a significant shift toward participants adopting a more conservative criterion when responding to the presence of the gap (i.e. they were more likely to say that a gap was not present). Taken together, these results demonstrate movement-related tactile sensory suppression and point to a decisional component in tactile suppression, thus suggesting that tactile suppression could already be triggered in the brain ahead of the motor command. PMID:21717097

  18. 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.

  19. Tactile feedback improves auditory spatial localization

    OpenAIRE

    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 b...

  20. Tactile feedback improves auditory spatial localization

    OpenAIRE

    Monica eGori; Tiziana eVercillo; Giulio eSandini; David eBurr

    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 b...

  1. Survey of Studies on Tactile Senses

    OpenAIRE

    Pohja, Seppo

    1996-01-01

    This survey is meant to serve computer scientists, mathematicians and others who need to get quickly acquainted with the most relevant results in the biology and psychology of the tactile senses but have little or no prior exposure to the field. The survey is written from the point of view of a computer scientists studying artificial neural networks (ANNs). Questions of relevancy - what to include and what to exclude in the survey - are always very subjective. This surv...

  2. Aero-tactile integration in speech perception

    OpenAIRE

    Gick, Bryan; Derrick, Donald

    2009-01-01

    Visual information from a speaker’s face can enhance1 or interfere with2 accurate auditory perception. This integration of information across auditory and visual streams has been observed in functional imaging studies3,4, and has typically been attributed to the frequency and robustness with which perceivers jointly encounter event-specific information from these two modalities5. Adding the tactile modality has long been considered a crucial next step in understanding multisensory integration...

  3. Millisecond Precision Spike Timing Shapes Tactile Perception

    OpenAIRE

    Mackevicius, Emily L.; Best, Matthew D.; Saal, Hannes P.; Bensmaia, Sliman J.

    2012-01-01

    In primates, the sense of touch has traditionally been considered to be a spatial modality, drawing an analogy to the visual system. In this view, stimuli are encoded in spatial patterns of activity over the sheet of receptors embedded in the skin. We propose that the spatial processing mode is complemented by a temporal one. Indeed, the transduction and processing of complex, high-frequency skin vibrations have been shown to play an important role in tactile texture perception, and the frequ...

  4. Développement de jauges de contrainte à base de nanoparticules colloïdales : Application à la réalisation de surfaces tactiles souples

    OpenAIRE

    Decorde, Nicolas,

    2014-01-01

    One recent big challenge is to implement innovative sensors that take advantage of the unique properties of colloidal nanoparticles chemically synthesized and assembled on various surfaces. The goal of this work is the development of nanoparticle based resistive strain gauges. These strain gauges are constructed of few micrometers wide parallel wires of close packed colloidal gold nanoparticles, chemically synthesized, and assembled on flexible substrates by convective self assembly. The prin...

  5. Tactile sensitivity on the hands skin in rheumatic patients

    OpenAIRE

    Kaluga, Elżbieta; Kostiukow, Anna; Samborski, Włodzimierz; Rostkowska, Elżbieta

    2014-01-01

    Introduction Clinical symptoms of rheumatic diseases can cause changes in the level of skin tactile sensitivity. Aim To determine the tactile threshold of the hands in female patients with rheumatic diseases. It also attempted to determine correlations between rheumatic patients’ tactile sensitivity and the degree of articular movement limitations, the Barthel Index (BI) and Edinburgh Handedness Inventory (EHI) results, the level of disability of the right hand and the left hand as well as ag...

  6. 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.

  7. Separate mechanisms for audio-tactile pitch and loudness interactions

    Directory of Open Access Journals (Sweden)

    JeffreyMYau

    2010-10-01

    Full Text Available A major goal in perceptual neuroscience is to understand how signals from different sensory modalities are combined to produce stable and coherent representations. We previously investigated interactions between audition and touch, motivated by the fact that both modalities are sensitive to environmental oscillations. In our earlier study, we characterized the effect of auditory distractors on tactile frequency and intensity perception. Here, we describe the converse experiments examining the effect of tactile distractors on auditory processing. Because the two studies employ the same psychophysical paradigm, we combined their results for a comprehensive view of how auditory and tactile signals interact and how these interactions depend on the perceptual task. Together, our results show that temporal frequency representations are perceptually linked regardless of the attended modality. In contrast, audio-tactile loudness interactions depend on the attended modality: Tactile distractors influence judgments of auditory intensity, but judgments of tactile intensity are impervious to auditory distraction. Lastly, we show that audio-tactile loudness interactions depend critically on stimulus timing, while pitch interactions do not. These results reveal that auditory and tactile inputs are combined differently depending on the perceptual task. That distinct rules govern the integration of auditory and tactile signals in pitch and loudness perception implies that the two are mediated by separate neural mechanisms. These findings underscore the complexity and specificity of multisensory interactions.

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

    Science.gov (United States)

    Liu, Yanjie; Han, Haijun; Liu, Tao; Yi, Jingang; Li, Qingguo; Inoue, Yoshio

    2016-01-01

    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. PMID:27023545

  9. 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.

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

    Science.gov (United States)

    Liu, Yanjie; Han, Haijun; Liu, Tao; Yi, Jingang; Li, Qingguo; Inoue, Yoshio

    2016-01-01

    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. PMID:27023545

  11. Additive manufacturing of stretchable tactile sensors: Processes, materials, and applications

    Science.gov (United States)

    Vatani, Morteza

    3D printing technology is becoming more ubiquitous every day especially in the area of smart structures. However, fabrication of multi-material, functional, and smart structures is problematic because of the process and material limitations. This thesis sought to develop a Direct Print Photopolymerization (DPP) fabrication technique that appreciably extends the manufacturing space for the 3D smart structures. This method employs a robotically controlled micro-extrusion of a filament equipped with a photopolymerization process. The ability to use polymers and ultimately their nanocomposites in this process is the advantage of the proposed process over the current fabrication methods in the fabrication of 3D structures featuring mechanical, physical, and electrical functionalities. In addition, this study focused to develop a printable, conductive, and stretchable nanocomposite based on a photocurable and stretchable liquid resin filled with multi-walled carbon nanotubes (MWNTs). This nanocomposite exhibited piezoresistivity, means its resistivity changes as it deforms. This property is a favorable factor in developing resistance based tactile sensors. They were also able to resist high tensile strains while they showed conductivity. Furthermore, this study offered a possible and low-cost method to have a unique and highly stretchable pressure sensitive polymer. This disruptive pressure sensitive polymer composed of an Ionic Liquid (IL) and a stretchable photopolymer embedded between two layers of Carbon Nanotube (CNTs) based stretchable electrodes. The developed IL-polymer showed both field effect property and piezoresistivity that can detect large tensile strains up 30%. In summary, this research study focused to present feasible methods and materials for printing a 3D smart structure especially in the context of flexible tactile sensors. This study provides a foundation for the future efforts in fabrication of skin like tactile sensors in three-dimensional motifs

  12. A modified analytical model to study the sensing performance of a flexible capacitive tactile sensor array

    International Nuclear Information System (INIS)

    This paper presents a modified analytical model to study the sensing performance of a flexible capacitive tactile sensor array, which utilizes solid polydimethylsiloxane (PDMS) film as the dielectric layer. To predict the deformation of the sensing unit and capacitance changes, each sensing unit is simplified into a three-layer plate structure and divided into central, edge and corner regions. The plate structure and the three regions are studied by the general and modified models, respectively. For experimental validation, the capacitive tactile sensor array with 8  ×  8 (= 64) sensing units is fabricated. Experiments are conducted by measuring the capacitance changes versus applied external forces and compared with the general and modified models’ predictions. For the developed tactile sensor array, the sensitivity predicted by the modified analytical model is 1.25%/N, only 0.8% discrepancy from the experimental measurement. Results demonstrate that the modified analytical model can accurately predict the sensing performance of the sensor array and could be utilized for model-based optimal capacitive tactile sensor array design. (paper)

  13. 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.

  14. Human spatial navigation via a visuo-tactile sensory substitution system.

    Science.gov (United States)

    Segond, Hervé; Weiss, Déborah; Sampaio, Eliana

    2005-01-01

    Spatial navigation within a real 3-D maze was investigated to study space perception on the sole basis of tactile information transmitted by means of a 'tactile vision substitution system' (TVSS) allowing the conversion of optical images-collected by a micro camera-into 'tactile images' via a matrix in contact with the skin. The development of such a device is based on concepts of cerebral and functional plasticity, enabling subjective reproduction of visual images from tactile data processing. Blindfolded sighted subjects had to remotely control the movements of a robot on which the TVSS camera was mounted. Once familiarised with the cues in the maze, the subjects were given two exploration sessions. Performance was analysed according to an objective point of view (exploration time, discrimination capacity), as well as a subjective one (speech). The task was successfully carried out from the very first session. As the subjects took a different path during each navigation, a gradual improvement in performance (discrimination and exploration time) was noted, generating a phenomenon of learning. Moreover, subjective analysis revealed an evolution of the spatialisation process towards distal attribution. Finally, some emotional expressions seemed to reflect the genesis of 'qualia' (emotional qualities of stimulation). PMID:16309117

  15. Modelling the response of a tactile array using electrorheological fluids

    International Nuclear Information System (INIS)

    This paper reports the first step in the development of a tactile array suitable for the presentation of haptic information in virtual reality. The system is based on the electric field dependence of the viscosity of electrorheological fluids. The simulation, as well as the experimental realization of single tactels is described. The mathematical approach is based on the Eckart model (Eckart W 2000 Continuum Mech. Thermodyn. 12 341-62) and its validity is demonstrated by comparing the resulting yield stress with the experimental results from Wunderlich (2000 Dissertation Universitaet Erlangen-Nuernberg). Two different tactel designs are realized and the experimental results are compared with numerical simulation. The design of modification B is shown to be applicable for the realization of an actuator array with high spatial resolution

  16. 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

  17. 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…

  18. 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…

  19. Response requirements modulate tactile spatial congruency effects.

    Science.gov (United States)

    Gallace, Alberto; Soto-Faraco, Salvador; Dalton, Polly; Kreukniet, Bas; Spence, Charles

    2008-11-01

    Several recent studies have provided support for the view that tactile stimuli/events are remapped into an abstract spatial frame of reference beyond the initial somatotopic representation present in the primary somatosensory cortex. Here, we demonstrate for the first time that the extent to which this remapping of tactile stimuli takes place is dependent upon the particular demands imposed by the task that participants have to perform. Participants in the present study responded to either the elevation (up vs. down) or to the anatomical location (finger vs. thumb) of vibrotactile targets presented to one hand, while trying to ignore distractors presented simultaneously to the other hand. The magnitude and direction of the target-distractor congruency effect was measured as participants adopted one of two different postures with each hand (palm-up or palm-down). When the participants used footpedal responses (toe vs. heel; Experiment 1), congruency effects were determined by the relative elevation of the stimuli in external coordinates (same vs. different elevation), regardless of whether the relevant response feature was defined externally or anatomically. Even when participants responded verbally (Experiment 2), the influence of the relative elevation of the stimuli in external space, albeit attenuated, was still observed. However, when the task involved responding with the stimulated finger (four-alternative forced choice; Experiment 3), congruency effects were virtually eliminated. These findings support the view that tactile events can be remapped according to an abstract frame of reference resulting from multisensory integration, but that the frame of reference that is used while performing a particular task may depend to a large extent on the nature of the task demands. PMID:18709500

  20. Neural correlates of tactile perception during pre-, peri-, and post-movement.

    Science.gov (United States)

    Juravle, Georgiana; Heed, Tobias; Spence, Charles; Röder, Brigitte

    2016-05-01

    Tactile information is differentially processed over the various phases of goal-directed movements. Here, event-related potentials (ERPs) were used to investigate the neural correlates of tactile and visual information processing during movement. Participants performed goal-directed reaches for an object placed centrally on the table in front of them. Tactile and visual stimulation (100 ms) was presented in separate trials during the different phases of the movement (i.e. preparation, execution, and post-movement). These stimuli were independently delivered to either the moving or resting hand. In a control condition, the participants only performed the movement, while omission (i.e. movement-only) ERPs were recorded. Participants were instructed to ignore the presence or absence of any sensory events and to concentrate solely on the execution of the movement. Enhanced ERPs were observed 80-200 ms after tactile stimulation, as well as 100-250 ms after visual stimulation: These modulations were greatest during the execution of the goal-directed movement, and they were effector based (i.e. significantly more negative for stimuli presented to the moving hand). Furthermore, ERPs revealed enhanced sensory processing during goal-directed movements for visual stimuli as well. Such enhanced processing of both tactile and visual information during the execution phase suggests that incoming sensory information is continuously monitored for a potential adjustment of the current motor plan. Furthermore, the results reported here also highlight a tight coupling between spatial attention and the execution of motor actions. PMID:26914480

  1. 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.

  2. Effect of tactile feedback on movement speed and precision during work-related tasks using a computer mouse.

    Science.gov (United States)

    Viau, Antonin; Najm, Micheline; Chapman, C Elaine; Levin, Mindy F

    2005-01-01

    Effects of tactile feedback on movement accuracy and speed were studied. Younger and older participants performed three tasks (1, select and drag word; 2, menu navigation; 3, select and drag cell) using commercial software and a mouse with or without tactile feedback. Task time and error number were recorded. Tasks were divided according to presence or absence of tactile feedback, and participants were divided into subgroups (high, average, low) based on Task 1 performance. Overall, older participants took longer (p errors (p errors (24%) on Task 1. Low- and average-performance younger participants benefited most from feedback for Task 1. Older low-performance participants also benefited from feedback for Task 1. For Task 3, older participants tended to take more time and make more errors with feedback. Tactile feedback may enhance performance when feedback is event related. Older people may not integrate sensation as well as younger individuals to enhance performance. Potential applications of this research include the development of tactile feedback interfaces to facilitate computer use. PMID:16553068

  3. Tactile length contraction as Bayesian inference.

    Science.gov (United States)

    Tong, Jonathan; Ngo, Vy; Goldreich, Daniel

    2016-08-01

    To perceive, the brain must interpret stimulus-evoked neural activity. This is challenging: The stochastic nature of the neural response renders its interpretation inherently uncertain. Perception would be optimized if the brain used Bayesian inference to interpret inputs in light of expectations derived from experience. Bayesian inference would improve perception on average but cause illusions when stimuli violate expectation. Intriguingly, tactile, auditory, and visual perception are all prone to length contraction illusions, characterized by the dramatic underestimation of the distance between punctate stimuli delivered in rapid succession; the origin of these illusions has been mysterious. We previously proposed that length contraction illusions occur because the brain interprets punctate stimulus sequences using Bayesian inference with a low-velocity expectation. A novel prediction of our Bayesian observer model is that length contraction should intensify if stimuli are made more difficult to localize. Here we report a tactile psychophysical study that tested this prediction. Twenty humans compared two distances on the forearm: a fixed reference distance defined by two taps with 1-s temporal separation and an adjustable comparison distance defined by two taps with temporal separation t ≤ 1 s. We observed significant length contraction: As t was decreased, participants perceived the two distances as equal only when the comparison distance was made progressively greater than the reference distance. Furthermore, the use of weaker taps significantly enhanced participants' length contraction. These findings confirm the model's predictions, supporting the view that the spatiotemporal percept is a best estimate resulting from a Bayesian inference process. PMID:27121574

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

    Directory of Open Access Journals (Sweden)

    Michael Brecht

    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.

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

    OpenAIRE

    Tezuka, Mayuko; Kitamura, Norihide; Tanaka, Kohei; Miki, Norihisa

    2016-01-01

    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 t...

  6. 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

  7. Acquisition of a 250-word vocabulary through a tactile vocoder.

    Science.gov (United States)

    Brooks, P L; Frost, B J; Mason, J L; Chung, K

    1985-04-01

    In a previous experiment [P. L. Scilley, "Evaluation of a vibrotactile auditory prosthetic device for the profoundly deaf," unpublished Masters thesis, Queen's University, Kingston, Canada (1980)] two normal subjects learned to identify 70 and 150 words, respectively, using the Queen's Tactile Vocoder. In the present experiment, the most advanced subject continued word learning until a tactile vocabulary of 250 words was acquired. At this point randomized tests were given to obtain an indication of final performance level. From these data conditional probabilities of correct response for each stimulus word and significant confusions were obtained, which provides insight into the advantages and present limitations of the tactile vocoder. PMID:3157716

  8. The effects of negative emotions on sensory perception: Fear but not anger decreases tactile sensitivity

    OpenAIRE

    Nicholas J Kelley; Schmeichel, Brandon J.

    2014-01-01

    Emotions and sensory perceptions are closely intertwined. Of the five senses sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances se...

  9. The effects of negative emotions on sensory perception: fear but not anger decreases tactile sensitivity

    OpenAIRE

    Nicholas J Kelley; Schmeichel, Brandon J.

    2014-01-01

    Emotions and sensory perceptions are closely intertwined. Of the five senses, sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances s...

  10. Tactile maze solving in congenitally blind individuals

    DEFF Research Database (Denmark)

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

    2010-01-01

    Vision is undoubtedly important for navigation although not essential as blind individuals outperform their blindfolded seeing counterparts in a variety of navigational tasks. It is believed that the blind's superior performance is because of their efficient use of proprioceptive signals 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....... Our results show that blindfolded sighted controls outperformed blind participants in the route-learning tasks. This suggests that, contrary to indoor large-scale spaces, navigational skills inside small-scale spaces benefit from visual experience....

  11. Optic flow improves adaptability of spatiotemporal characteristics during split-belt locomotor adaptation with tactile stimulation.

    Science.gov (United States)

    Eikema, Diderik Jan A; Chien, Jung Hung; Stergiou, Nicholas; Myers, Sara A; Scott-Pandorf, Melissa M; Bloomberg, Jacob J; Mukherjee, Mukul

    2016-02-01

    Human locomotor adaptation requires feedback and feed-forward control processes to maintain an appropriate walking pattern. Adaptation may require the use of visual and proprioceptive input to decode altered movement dynamics and generate an appropriate response. After a person transfers from an extreme sensory environment and back, as astronauts do when they return from spaceflight, the prolonged period required for re-adaptation can pose a significant burden. In our previous paper, we showed that plantar tactile vibration during a split-belt adaptation task did not interfere with the treadmill adaptation however, larger overground transfer effects with a slower decay resulted. Such effects, in the absence of visual feedback (of motion) and perturbation of tactile feedback, are believed to be due to a higher proprioceptive gain because, in the absence of relevant external dynamic cues such as optic flow, reliance on body-based cues is enhanced during gait tasks through multisensory integration. In this study, we therefore investigated the effect of optic flow on tactile-stimulated split-belt adaptation as a paradigm to facilitate the sensorimotor adaptation process. Twenty healthy young adults, separated into two matched groups, participated in the study. All participants performed an overground walking trial followed by a split-belt treadmill adaptation protocol. The tactile group (TC) received vibratory plantar tactile stimulation only, whereas the virtual reality and tactile group (VRT) received an additional concurrent visual stimulation: a moving virtual corridor, inducing perceived self-motion. A post-treadmill overground trial was performed to determine adaptation transfer. Interlimb coordination of spatiotemporal and kinetic variables was quantified using symmetry indices and analyzed using repeated-measures ANOVA. Marked changes of step length characteristics were observed in both groups during split-belt adaptation. Stance and swing time symmetries were

  12. Quantifying Different Tactile Sensations Evoked by Cutaneous Electrical Stimulation Using Electroencephalography Features.

    Science.gov (United States)

    Zhang, Dingguo; Xu, Fei; Xu, Heng; Shull, Peter B; Zhu, Xiangyang

    2016-03-01

    Psychophysical tests and standardized questionnaires are often used to analyze tactile sensation based on subjective judgment in conventional studies. In contrast with the subjective evaluation, a novel method based on electroencephalography (EEG) is proposed to explore the possibility of quantifying tactile sensation in an objective way. The proposed experiments adopt cutaneous electrical stimulation to generate two kinds of sensations (vibration and pressure) with three grades (low/medium/strong) on eight subjects. Event-related potentials (ERPs) and event-related synchronization/desynchronization (ERS/ERD) are extracted from EEG, which are used as evaluation indexes to distinguish between vibration and pressure, and also to discriminate sensation grades. Results show that five-phase P1–N1–P2–N2–P3 deflection is induced in EEG. Using amplitudes of latter ERP components (N2 and P3), vibration and pressure sensations can be discriminated on both individual and grand-averaged ERP (p ERPs can distinguish the three sensations grades, but there is no significant difference on individuals. In addition, ERS/ERD features of mu rhythm (8–13 Hz) are adopted. Vibration and pressure sensations can be discriminated on grand-average ERS/ERD (p ERP- and ERS/ERD-based EEG features may have potential to quantify tactile sensations for medical diagnosis or engineering applications. PMID:26762865

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

    DEFF Research Database (Denmark)

    Ask Larsen, Flemming

    2013-01-01

    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 as......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...... a first language is presently a theoretic possibility. We need more research on how to accommodate TSL to language Development and on how to fit TSL into participation in complex cultural activities....

  14. Insights into the Capabilities of Tactile-Foot Perception

    Directory of Open Access Journals (Sweden)

    Ramiro Velázquez

    2012-11-01

    Full Text Available This paper presents a novel wearable interface for the foot: a shoe‐integrated tactile display that enables users to obtain information through the sense of touch via their feet. A 16‐point array of actuators stimulates the sole of the foot by inducing different vibration frequencies. A series of experiments were conducted with 20 sighted and 5 blind voluntary subjects to evaluate the role of tactile perception by the human foot and the tactile sensitivity of the plantar surface. Tests evaluated the perception of simple shapes, patterns and directional instructions. The results showed that some information is discriminable and that tactile‐foot stimulation could be used for a wide number of applications in human‐machine interaction. Furthermore, the results also suggested that the blind perform better in some key tasks and support the feasibility of footwear providing tactile feedback for situational awareness, mobility and the navigation assistance of the blind.

  15. 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.

  16. Tactile Perception in Adults with Autism: a Multidimensional Psychophysical Study

    OpenAIRE

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

    2007-01-01

    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 submodality of somatosensation. At both sites, the groups displayed similar thresholds for detecting light touch and innocuous sensations of warmth and cool,...

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

    OpenAIRE

    Cohen, William A.

    2014-01-01

    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...

  18. Interactive Display under the Influence of Tactile Sense

    Institute of Scientific and Technical Information of China (English)

    ZHU Ge-yang; YAO Jing

    2010-01-01

    Humans have a variety of sense in dynamic environment,and tactile sensation is an important way apperceiving the world.It enhances the process of experience and the interaction between humans and environment.However,vision as a dominant sense impairs the variety of sense.In the display design,current designers often put more emphasi on structure,form,color,such other visual elements,consequently neglect the importance of the tactile sensation,which weakens real experience of humans.

  19. Tactile Sun: Bringing an Invisible Universe to the Visually Impaired

    Science.gov (United States)

    Isidro, G. M.; Pantoja, C. A.

    2014-07-01

    A tactile model of the Sun has been created as a strategy for communicating astronomy to the blind or visually impaired, and as a useful outreach tool for general audiences. The model design was a collaboration between an education specialist, an astronomy specialist and a sculptor. The tactile Sun has been used at astronomy outreach events in Puerto Rico to make activities more inclusive and to increase public awareness of the needs of those with disabilities.

  20. A high speed sensor system for tactile interaction research

    OpenAIRE

    Schürmann, Carsten

    2013-01-01

    In this work we will describe and implement the first tactile sensor system that combines the properties of modularity with a very high sensing speed, a high sensitivity and a high spatial resolution. This unique combination of features enables researchers to develop novel applications and makes it possible to replace task specific tactile sensors with a single system. The very high sensing speed of the system allows for slip detection during robot grasping. And as all our sensor cells...

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

    OpenAIRE

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

    2016-01-01

    International audience 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 th...

  2. 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

  3. 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

    2016-01-01

    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. PMID:27271631

  4. Flexible tactile sensor for shear stress measurement using transferred sub-µm-thick Si piezoresistive cantilevers

    International Nuclear Information System (INIS)

    We propose a flexible tactile sensor using sub-µm-thick Si piezoresistive cantilevers for shear stress detection. The thin Si piezoresistive cantilevers were fabricated on the device layer of a silicon on insulator (SOI) wafer. By using an adhesion-based transfer method, only these thin and fragile cantilevers were transferred from the rigid handling layer of the SOI wafer to the polydimethylsiloxane layer without damage. Because the thin Si cantilevers have high durability of bending, the proposed sensor can be attached to a thin rod-type structure serving as the finger of a robotic hand. The cantilevers were arrayed in orthogonal directions to measure the X and Y directional components of applied shear stresses independently. We evaluated the bending durability of our flexible tactile sensor and confirmed that the sensor can be attached to a rod with a radius of 10 mm. The sensitivity of the flexible tactile sensor attached to a curved surface was 1.7 × 10−6 Pa−1 on average for a range of shear stresses from −1.8 × 103 to 1.8 × 103 Pa applied along its surface. It independently detected the X and Y directional components of the applied shear stresses. (paper)

  5. Speech intelligibility of children with cochlear implants, tactile aids, or hearing aids.

    Science.gov (United States)

    Osberger, M J; Maso, M; Sam, L K

    1993-02-01

    Speech intelligibility was measured in 31 children who used the 3M/House single-channel implant (n = 12), the Nucleus 22-Channel Cochlear Implant System (n = 15), or the Tactaid II + two-channel vibrotactile aid (n = 4). The subjects were divided into subgroups based on age at onset of deafness (early or late). The speech intelligibility of the experimental subjects was compared to that of children who were profoundly hearing impaired who used conventional hearing aids (n = 12) or no sensory aid (n = 2). The subjects with early onset of deafness who received their single- or multichannel cochlear implant before age 10 demonstrated the highest speech intelligibility, whereas subjects who did not receive their device until after age 10 had the poorest speech intelligibility. There was no obvious difference in the speech intelligibility scores of these subjects as a function of type of device (implant or tactile aid). On the average, the postimplant or tactile aid speech intelligibility of the subjects with early onset of deafness was similar to that of hearing aid users with hearing levels between 100 and 110 dB HL and limited hearing in the high frequencies. The speech intelligibility of subjects with late onset of deafness showed marked deterioration after the onset of deafness with relatively large improvements by most subjects after they received a single- or multichannel implant. The one subject with late onset of deafness who used a tactile aid showed no improvement in speech intelligibility. PMID:8450658

  6. Object-shape recognition and 3D reconstruction from tactile sensor images.

    Science.gov (United States)

    Khasnobish, Anwesha; Singh, Garima; Jati, Arindam; Konar, Amit; Tibarewala, D N

    2014-04-01

    This article presents a novel approach of edged and edgeless object-shape recognition and 3D reconstruction from gradient-based analysis of tactile images. We recognize an object's shape by visualizing a surface topology in our mind while grasping the object in our palm and also taking help from our past experience of exploring similar kind of objects. The proposed hybrid recognition strategy works in similar way in two stages. In the first stage, conventional object-shape recognition using linear support vector machine classifier is performed where regional descriptors features have been extracted from the tactile image. A 3D shape reconstruction is also performed depending upon the edged or edgeless objects classified from the tactile images. In the second stage, the hybrid recognition scheme utilizes the feature set comprising both the previously obtained regional descriptors features and some gradient-related information from the reconstructed object-shape image for the final recognition in corresponding four classes of objects viz. planar, one-edged object, two-edged object and cylindrical objects. The hybrid strategy achieves 97.62 % classification accuracy, while the conventional recognition scheme reaches only to 92.60 %. Moreover, the proposed algorithm has been proved to be less noise prone and more statistically robust. PMID:24469960

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

    International Nuclear Information System (INIS)

    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.

  8. 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. PMID:27187496

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

    Directory of Open Access Journals (Sweden)

    Łukasz Bola

    Full Text Available 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.

  10. 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. PMID:27187496

  11. 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

  12. Microstamped opto-mechanical actuator for tactile displays

    Science.gov (United States)

    Camargo, Carlos J.; Torras, Núria; Campanella, Humberto; Marshall, Jean E.; Zinoviev, Kirill; Campo, Eva M.; Terentjev, Eugene M.; Esteve, Jaume

    2011-10-01

    Over the last few years, several technologies have been adapted for use in tactile displays, such as thermo-pneumatic actuators, piezoelectric polymers and dielectric elastomers. None of these approaches offers high-performance for refreshable Braille display system (RBDS), due to considerations of weight, power efficiency and response speed. Optical actuation offers an attractive alternative to solve limitations of current-art technologies, allowing electromechanical decoupling, elimination of actuation circuits and remote controllability. Creating these opticallydriven devices requires liquid crystal - carbon nanotube (LC-CNT) composites that show a reversible shape change in response to an applied light. This work thus reports on novel opto-actuated Braille dots based on LC-CNT composite and silicon mold microstamping. The manufacturing approach succeeds on producing blisters according to the Braille standard for the visually impaired, by taking shear-aligned LC-CNT films and silicon stamps. For this application, we need to define specifically-shaped structures. Some technologies have succeeded on elastomer microstructuring. Nevertheless, they are not applicable for LC-CNT molding because they do not consider the stretching of the polymer which is required for LC-CNT fabrication. Our process demonstrates that composites micro-molding and their 3-D structuring is feasible by silicon-based stamping. Its work principle involves the mechanical stretching, allowing the LC mesogens alignment.

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

    Science.gov (United States)

    Aggarwal, Achint; Kirchner, Frank

    2014-01-01

    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. PMID:24553087

  14. 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.

  15. Control of the visual and tactile aspects of poultry food according to the poultry food behavior by image analysis

    Science.gov (United States)

    Hachemi, R.; Vincent, N.; Lomenie, N.

    2007-01-01

    This study tries to connect the poultry food behavior to the visual and tactile characteristics of the food. The aim of the work is to make it possible to control the visual and tactile aspects of food (food pellets), by means of image analysis. These aspects are often suspected to explain the undesirable behavior of the poultries, which can reject a food, showing however optimal nutritional characteristics. These incidents involve important negative consequences as well for the animal as for the poultry breeder, with a major degradation of the technical and economic performances. Many zootechnical studies and observations in breeding testify to the sensitivity of the poultries to the visual and tactile aspects of food, but measurements classically used to characterize them do not allow explaining this phenomenon. Color, texture and shape features extracted from images of pellets will constitute effective and practical measures to describe their visual and tactile aspects. We show that a pellets classification based on visual features and supervised by a set of poultry food behavior labels allows to select a set of discriminating features.

  16. Numerosity judgments for tactile stimuli distributed over the body surface.

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2006-01-01

    A large body of research now supports the claim that two different and dissociable processes are involved in making numerosity judgments regarding visual stimuli: subitising (fast and nearly errorless) for up to 4 stimuli, and counting (slow and error-prone) when more than 4 stimuli are presented. We studied tactile numerosity judgments for combinations of 1-7 vibrotactile stimuli presented simultaneously over the body surface. In experiment 1, the stimuli were presented once, while in experiment 2 conditions of single presentation and repeated presentation of the stimulus were compared. Neither experiment provided any evidence for a discontinuity in the slope of either the RT or error data suggesting that subitisation does not occur for tactile stimuli. By systematically varying the intensity of the vibrotactile stimuli in experiment 3, we were able to demonstrate that participants were not simply using the 'global intensity' of the whole tactile display to make their tactile numerosity judgments, but were, instead, using information concerning the number of tactors activated. The results of the three experiments reported here are discussed in relation to current theories of counting and subitising, and potential implications for the design of tactile user interfaces are highlighted. PMID:16583769

  17. 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.

  18. Remapping motion across modalities: tactile rotations influence visual motion judgments.

    Science.gov (United States)

    Butz, Martin V; Thomaschke, Roland; Linhardt, Matthias J; Herbort, Oliver

    2010-11-01

    Multisensory interactions between haptics and vision remain poorly understood. Previous studies have shown that shapes, such as letters of the alphabet, when drawn on the skin, are differently perceived dependent upon which body part is stimulated and on how the stimulated body part, such as the hand, is positioned. Another line of research within this area has investigated multisensory interactions. Tactile perceptions, for example, have the potential to disambiguate visually perceived information. While the former studies focused on explicit reports about tactile perception, the latter studies relied on fully aligned multisensory stimulus dimensions. In this study, we investigated to what extent rotating tactile stimulations on the hand affect directional visual motion judgments implicitly and without any spatial stimulus alignment. We show that directional tactile cues and ambiguous visual motion cues are integrated, thus biasing the judgment of visually perceived motion. We further show that the direction of the tactile influence depends on the position and orientation of the stimulated part of the hand relative to a head-centered frame of reference. Finally, we also show that the time course of the cue integration is very versatile. Overall, the results imply immediate directional cue integration within a head-centered frame of reference. PMID:20878396

  19. 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 position...

  20. Mutual capacitance of liquid conductors in deformable tactile sensing arrays

    International Nuclear Information System (INIS)

    Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters

  1. Mutual capacitance of liquid conductors in deformable tactile sensing arrays

    Science.gov (United States)

    Li, Bin; Fontecchio, Adam K.; Visell, Yon

    2016-01-01

    Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

  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. Mutual capacitance of liquid conductors in deformable tactile sensing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin [Electrical and Computer Engineering Department, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Fontecchio, Adam K. [Electrical and Computer Engineering and Materials Science and Engineering Departments, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Visell, Yon [Electrical and Computer Engineering Department, Media Arts and Technology, California NanoSystems Institute, University of California, Santa Barbara, California 93106 (United States)

    2016-01-04

    Advances in highly deformable electronics are needed in order to enable emerging categories of soft computing devices ranging from wearable electronics, to medical devices, and soft robotic components. The combination of highly elastic substrates with intrinsically stretchable conductors holds the promise of enabling electronic sensors that can conform to curved objects, reconfigurable displays, or soft biological tissues, including the skin. Here, we contribute sensing principles for tactile (mechanical image) sensors based on very low modulus polymer substrates with embedded liquid metal microfluidic arrays. The sensors are fabricated using a single-step casting method that utilizes fine nylon filaments to produce arrays of cylindrical channels on two layers. The liquid metal (gallium indium alloy) conductors that fill these channels readily adopt the shape of the embedding membrane, yielding levels of deformability greater than 400%, due to the use of soft polymer substrates. We modeled the sensor performance using electrostatic theory and continuum mechanics, yielding excellent agreement with experiments. Using a matrix-addressed capacitance measurement technique, we are able to resolve strain distributions with millimeter resolution over areas of several square centimeters.

  4. Tactile and visual perception of injection moulded plastic parts

    DEFF Research Database (Denmark)

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

    In today’s world the technical development have reached high levels in many products. This means that the technical specifications are not as high a competition factor as it has been. Therefore the visual appeal (aesthetics) and tactile perception (ergonomics) have become much more important in t...... number of ways including measuring of surface roughness, contact angle, gloss measurement and human perception.......In today’s world the technical development have reached high levels in many products. This means that the technical specifications are not as high a competition factor as it has been. Therefore the visual appeal (aesthetics) and tactile perception (ergonomics) have become much more important in...... 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 in a...

  5. 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 tow

  6. Effects of a Wearable, Tactile Aid on Language Comprehension of Prelingual Profoundly Deaf Children.

    Science.gov (United States)

    Proctor, Adele

    Factors influencing the use of nonacoustic aids (such as visual displays and tactile devices) with the hearing impaired are reviewed. The benefits of tactile devices in improving speech reading/lipreading and speech are pointed out. Tactile aids which provide information on rhythm, rate, intensity, and duration of speech increase lipreading and…

  7. Early Intervention with a Parent-Delivered Massage Protocol Directed at Tactile Abnormalities Decreases Severity of Autism and Improves Child-to-Parent Interactions: A Replication Study.

    Science.gov (United States)

    Silva, Louisa M T; Schalock, Mark; Gabrielsen, Kristen R; Budden, Sarojini S; Buenrostro, Martha; Horton, Gretchen

    2015-01-01

    Tactile abnormalities are severe and universal in preschool children with autism. They respond well to treatment with a daily massage protocol directed at tactile abnormalities (QST massage for autism). Treatment is based on a model for autism proposing that tactile impairment poses a barrier to development. Two previous randomized controlled trials evaluating five months of massage treatment reported improvement of behavior, social/communication skills, and tactile and other sensory symptoms. This is the first report from a two-year replication study evaluating the protocol in 103 preschool children with autism. Parents gave daily treatment; trained staff gave weekly treatment and parent support. Five-month outcomes replicated earlier studies and showed normalization of receptive language (18%, P = .03), autistic behavior (32%, P = .006), total sensory abnormalities (38%, P = .0000005), tactile abnormalities (49%, P = .0002), and decreased autism severity (medium to large effect size, P = .008). In addition, parents reported improved child-to-parent interactions, bonding, and decreased parenting stress (44%, P = .00008). Early childhood special education programs are tasked with addressing sensory abnormalities and engaging parents in effective home programs. Until now, they have lacked research-based methods to do so. This program fulfills the need. It is recommended to parents and ECSE programs (ages 3-5) at autism diagnosis. PMID:25878901

  8. 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

  9. Improvements of optical tactile sensors for robotic system by gold nanocomposite material.

    Science.gov (United States)

    Massaro, A; Spano, F; Cazzato, P; Cingolani, R; Athanassiou, A

    2012-06-01

    In this work we propose the evolution of a new class of optical pressure sensors suitable for robot tactile sensing. The sensors are based on a tapered optical fiber, where optical signals travel embedded into a PDMS-gold nanocomposite material. By applying different pressure forces on the PDMS-based nanocomposite we measure in real time the change of the optical transmitted intensity due to the coupling between the gold nanocomposite material and the tapered fiber region. The intensity reduction of the transmitted light intensity is correlated with the pressure force magnitude. PMID:22905545

  10. 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...

  11. 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...

  12. 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…

  13. Tactile feedback to the palm using arbitrarily shaped DEA

    Science.gov (United States)

    Mößinger, Holger; Haus, Henry; Kauer, Michaela; Schlaak, Helmut F.

    2014-03-01

    Tactile stimulation enhances user experience and efficiency in human machine interaction by providing information via another sensory channel to the human brain. DEA as tactile interfaces have been in the focus of research in recent years. Examples are (vibro-) tactile keyboards or Braille displays. These applications of DEA focus mainly on interfacing with the user's fingers or fingertips only - demonstrating the high spatial resolution achievable with DEA. Besides providing a high resolution, the flexibility of DEA also allows designing free form surfaces equipped with single actuators or actuator matrices which can be fitted to the surface of the human skin. The actuators can then be used to provide tactile stimuli to different areas of the body, not to the fingertips only. Utilizing and demonstrating this flexibility we designed a free form DEA pad shaped to fit into the inside of the human palm. This pad consists of four single actuators which can provide e.g. directional information such as left, right, up and down. To demonstrate the value of such free form actuators we manufactured a PC-mouse using 3d printing processes. The actuator pad is mounted on the back of the mouse, resting against the palm while operating it. Software on the PC allows control of the vibration patterns displayed by the actuators. This allows helping the user by raising attention to certain directions or by discriminating between different modes like "pick" or "manipulate". Results of first tests of the device show an improved user experience while operating the PC mouse.

  14. The construction of tactile graphics for blind students

    Directory of Open Access Journals (Sweden)

    Bruno Zucherato

    2011-06-01

    Full Text Available After 1990's access expansion to education for students with special needs has emerged as a very pertinent issue regarding educational policies. In this scenario, we emphasize the teaching of geography for the visually impaired, blind and low vision students, focusing more specifically on the graphics in teaching geography. The  objective of this paper is to report the experiences obtained from August 2008 to August 2009 by UNESP at Rio Claro extension group entitled "Tactile Cartography and MAPAVOX: An alternative way to construct tactile maps and games". During practices conducted for this paper histograms and pie charts were constructed with active participation of students in the whole process. The methodology used in this article was the qualitative research in education, creating an unparalleled analysis of the results and building reports from practices at special school. The final built tactile charts turned to be an important alternative method for teaching graphics for blind and low vision students, using simple features such as low cost materials and taking into account the concern and understanding of visually impaired students in the construction of tactile graphics. The survey results used as the basis for the article will also serve as the basis for the construction of a guide book for teachers who have students who are blind or have low vision in her classroom.

  15. 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.…

  16. Durable Tactile Glove for Human or Robot Hand

    Science.gov (United States)

    Butzer, Melissa; Diftler, Myron A.; Huber, Eric

    2010-01-01

    A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

  17. Sensing Characteristics of an Experimental CT Tactile Sensor

    Science.gov (United States)

    Sawamoto, Yasuhiro; Ohka, Masahiro; Zhu, Ning

    The CT (Computed tomography) method is very effective for making thinner optical waveguide-type tactile sensors. In a previous paper, the authors established the architecture of a CT tactile sensor and evaluated its principle using a series of computer simulations. As a result, the LU decomposition method showed better noise robustness compared to the ART method. On the basis of the simulations, we develop an experimental CT tactile sensor comprised of infrared diodes, phototransistors, an acrylic plate and a black rubber sheet. In the present study, the LU decomposition method is employed and we determine the validity of the algorithm by examining use of a loading machine produced for the CT tactile sensor. In a series of experiments, it is found that absorption of light intensity increases monotonically with increase of applied force and that the present reconstruction method can be applied to not only simply but also multiply connected contact domains. The estimated position of the pressure centroid possesses a rather large error of 4.9 mm, which is 10.8% of a segment of the sensing area.

  18. 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.

  19. Simultaneous Stimulus Preexposure Enhances Human Tactile Perceptual Learning

    Science.gov (United States)

    Rodríguez, Gabriel; Angulo, Rocío

    2014-01-01

    An experiment with human participants established a novel procedure to assess perceptual learning with tactile stimuli. Participants received unsupervised exposure to two sandpaper surfaces differing in roughness (A and B). The ability of the participants to discriminate between the stimuli was subsequently assessed on a same/different test. It…

  20. Suppl\\'eance perceptive par \\'electro-stimulation linguale embarqu\\'ee : perspectives pour la pr\\'evention des escarres chez le bless\\'e m\\'edullaire

    CERN Document Server

    Chenu, Olivier; Moreau-Gaudry, Alexandre; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. This paper proposes an application for pressure sores prevention in case of spinal cord injuries (persons with paraplegia, or tetraplegia).

  1. Suppl\\'eance perceptive par \\'electro-stimulation linguale embarqu\\'ee : perspectives pour la pr\\'evention des escarres chez le bless\\'e m\\'edullaire

    OpenAIRE

    Chenu, Olivier; Vuillerme, Nicolas; Moreau-Gaudry, Alexandre; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. This paper proposes an application for pressure sores prevention in case of spinal cord inju...

  2. Suppléance perceptive par électro-stimulation linguale embarquée : perspectives pour la prévention des escarres chez le blessé médullaire

    OpenAIRE

    Chenu, Olivier; Vuillerme, Nicolas; Moreau-Gaudry, Alexandre; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. This paper proposes an application for pressure sores prevention in case of spinal cord inju...

  3. Neuroplasticity associated with tactile language communication in a deaf-blind subject

    Directory of Open Access Journals (Sweden)

    Souzana Obretenova

    2010-01-01

    Full Text Available A longstanding debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI, we compared the neural networks associated with the tactile reading of words presented in Braille, Print on Palm (POP, and a haptic form of American Sign Language (haptic ASL or hASL. With all three modes of tactile communication, indentifying words was associated with robust activation within occipital cortical regions as well as posterior superior temporal and inferior frontal language areas (lateralized within the left hemisphere. In a normally sighted and hearing interpreter, identifying words through hASL was associated with left-lateralized activation of inferior frontal language areas however robust occipital cortex activation was not observed. Diffusion tensor imaging (DTI-based tractography revealed differences consistent with enhanced occipital-temporal connectivity in the deaf-blind subject. Our results demonstrate that in the case of early onset of both visual and auditory deprivation, tactile-based communication is associated with an extensive cortical network implicating occipital as well as posterior superior temporal and frontal associated language areas. The cortical areas activated in this deaf-blind subject are consistent with characteristic cortical regions previously implicated with language. Finally, the resilience of language function within the context of early and combined visual and auditory deprivation may be related to enhanced connectivity between relevant cortical areas.

  4. 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.

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

    OpenAIRE

    Luca Patanè; Volker Dürr

    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...

  6. 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

  7. The failure to detect tactile change: a tactile analogue of visual change blindness.

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2006-04-01

    A large body of empirical research now shows that people are surprisingly poor at detecting significant changes in visually presented scenes. This phenomenon is known as change blindness in vision. A similar phenomenon occurs in audition, but to date no such effect has been documented in touch. In the present study, we explored the ability of people to detect changes introduced between two consecutively presented vibrotactile patterns presented over the body surface. The patterns consisted of two or three vibrotactile stimuli presented for 200 msec. The position of one of the vibrotactile stimuli composing the display was repeatedly changed (alternating between two different positions) on 50% of the trials, but the same pattern was presented repeatedly on the remaining trials. Three conditions were investigated: No interval between the patterns, an empty interval between the patterns, and a masked interval between the patterns. Change detection was near perfect in the no-interval block. Performance deteriorated somewhat in the empty-interval block, but by far the worst change detection performance occurred in the masked-interval block. These results demonstrate that "change blindness" can also affect tactile perception. PMID:16892998

  8. Integrated dynamic and static tactile sensor: focus on static force sensing

    Science.gov (United States)

    Wettels, Nicholas; Pletner, Baruch

    2012-04-01

    Object grasping by robotic hands in unstructured environments demands a sensor that is durable, compliant, and responsive to static and dynamic force conditions. In order for a tactile sensor to be useful for grasp control in these, it should have the following properties: tri-axial force sensing (two shear plus normal component), dynamic event sensing across slip frequencies, compliant surface for grip, wide dynamic range (depending on application), insensitivity to environmental conditions, ability to withstand abuse and good sensing behavior (e.g. low hysteresis, high repeatability). These features can be combined in a novel multimodal tactile sensor. This sensor combines commercial-off-the-shelf MEMS technology with two proprietary force sensors: a high bandwidth device based on PZT technology and low bandwidth device based on elastomers and optics. In this study, we focus on the latter transduction mechanism and the proposed architecture of the completed device. In this study, an embedded LED was utilized to produce a constant light source throughout a layer of silicon rubber which covered a plastic mandrel containing a set of sensitive phototransistors. Features about the contacted object such as center of pressure and force vectors can be extracted from the information in the changing patterns of light. The voltage versus force relationship obtained with this molded humanlike finger had a wide dynamic range that coincided with forces relevant for most human grip tasks.

  9. Tactile soft-sparse mean fluid-flow imaging with a robotic whisker array.

    Science.gov (United States)

    Tuna, Cagdas; Jones, Douglas L; Kamalabadi, Farzad

    2015-08-01

    An array of whiskers is critical to many mammals to survive in their environment. However, current engineered systems generally employ vision, radar or sonar to explore the surroundings, not having sufficiently benefited from tactile perception. Inspired by the whisking animals, we present here a novel tomography-based tactile fluid-flow imaging technique for the reconstruction of surroundings with an artificial whisker array. The moment sensed at the whisker base is the weighted integral of the drag force per length, which is proportional to the relative velocity squared on a whisker segment. We demonstrate that the 2D cross-sectional mean fluid-flow velocity-field can be successfully mapped out by collecting moment measurements at different angular positions with the whisker array. We use a regularized version of the FOCal underdetermined system solver algorithm with a smoothness constraint to obtain soft-sparse static estimates of the 2D cross-sectional velocity-squared distribution. This new proposed approach has the strong potential to be an alternative environmental sensing technology, particularly in dark or murky environments. PMID:26241787

  10. Support for the slip hypothesis from whisker-related tactile perception of rats in a noisy environment

    Directory of Open Access Journals (Sweden)

    Christian eWaiblinger

    2015-10-01

    Full Text Available Rodents use active whisker movements to explore their environment. The ‘slip hypothesis’ of whisker-related tactile perception entails that short-lived kinematic events (abrupt whisker movements, called ‘slips’, due to bioelastic whisker properties that occur during active touch of textures carry the decisive texture information. Supporting this hypothesis, previous studies have shown that slip amplitude and frequency occur in a texture dependent way. Further, experiments employing passive pulsatile whisker deflections revealed that perceptual performance based on pulse kinematics (i.e. signatures that resemble slips is far superior to the one based on time-integrated variables like frequency and intensity. So far, pulsatile stimuli were employed in a noise free environment. However, the realistic scenario involves background noise (e.g. evoked by rubbing across the texture. Therefore, if slips are used for tactile perception, the tactile neuronal system would need to differentiate slip-evoked spikes from those evoked by noise. To test the animals under these more realistic conditions, we presented passive whisker-deflections to head-fixed trained rats, consisting of 'slip-like' events (waveforms mimicking slips occurring with touch of real textures embedded into background noise. Varying the i shapes (ramp or pulse, ii kinematics (amplitude, velocity, etc., and iii the probabilities of occurrence of slip-like events, we observed that rats could readily detect slip-like events of different shapes against noisy background. Psychophysical curves revealed that the difference of slip event and noise amplitude determined perception, while increased probability of occurrence (frequency had barely any effect. These results strongly support the notion that encoding of kinematics dominantly determines whisker-related tactile perception while the computation of frequency or intensity plays a minor role.

  11. 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.

  12. Sheet-like ultrasonic transducer for tactile display application

    Science.gov (United States)

    Takasaki, Masaya; Suzaki, Michihiro; Mizuno, Takeshi

    2012-05-01

    A sheet-like ultrasonic transducer (SUT) was proposed to realize tactile feedback on a touchscreen. Exciting normal vibration on the SUT surface, basic principle of surface acoustic wave can be applied. Prototype of the SUT was fabricated using silica glass substrate whose dimension was 60 × 60 × 0.3 mm3 and a LiNbO3 piece with an interdigital transducer. To show feasibility of SUT application for the tactile feedback, friction between the SUT and a slider, which is installed on operator's fingertip, was measured. The friction was reduced by ultrasonic vibration of the SUT. The prototype SUT was installed on a touchscreen and controlled to indicate roughness. Under the control, roughness sensation was experienced successfully. Additionally, a larger SUT was fabricated and tested.

  13. Soft capacitive tactile sensing arrays fabricated via direct filament casting

    Science.gov (United States)

    Li, Bin; Gao, Yang; Fontecchio, Adam; Visell, Yon

    2016-07-01

    Advances in soft electronics are enabling the development of mechanical sensors that can conform to curved surfaces or soft objects, allowing them to interface seamlessly with the human body. In this paper, we report on intrinsically deformable tactile sensing arrays that achieve a unique combination of high spatial resolution, sensitivity, and mechanical stretchability. The devices are fabricated via a casting process that yields arrays of microfluidic channels in low modulus polymer membranes with thickness as small as one millimeter. Using liquid metal alloy as a conductor, we apply matrix-addressed capacitive sensing in order to resolve spatially distributed strain with millimeter precision over areas of several square centimeters. Due to the use of low-modulus polymers, the devices readily achieve stretchability greater than 500%, making them well suited for novel applications in wearable tactile sensing for biomedical applications.

  14. 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.

  15. "Touch me": workshop on tactile user experience evaluation methods

    OpenAIRE

    Tscheligi, Manfred; Isbister, Katherine; Höök, Kristina; Obrist, Marianna; Busch, Marc; Hochleitner, Christina

    2014-01-01

    In this workshop we plan to explore the possibilities and challenges of physical objects and materials for evaluating the User Experience (UX) of interactive systems. These objects should face shortfalls of current UX evaluation methods and allow for a qualitative (or even quantitative), playful and holistic evaluation of UX -- without interfering with the users' personal experiences during interaction. This provides a tactile enhancement to a solely visual stimulation as used in classical ev...

  16. Evaluation of tactile sensors in apple firmness measurement

    OpenAIRE

    Petit, Catherine; Leemans, Vincent; Kleynen, Olivier; Destain, Marie-France

    2001-01-01

    The objective of the work consists to develop a non-destructive fruit firmness measurement. The tactile sensor technology was chosen. The force measurement acting between the fruit-sensor as well as the contact area are coupled with other meaqsurements, like the color of the fruit. The results of the measurements are compared with the firmness reference values (Magness-Taylor test) and also with the acoustic impulse response technique. Several parameters correlated with firmness are proposed.

  17. On the effects of tactile touch in Parkinson's disease patients

    OpenAIRE

    Skogar, Örjan

    2013-01-01

    Background: Tactile Touch as a treatment modality is, in broad terms, scientifically unexplored. Patients use Complementary and Alternative Medicine (CAM) forms of treatment outside the area of pharmaceuticals to a great extent, particularly patients suffering from chronic diseases. Delineating and evaluating patients’ own experiences of alleviation using different treatment forms are important tasks for modern health services. The search for humoral substrates that reflect bodily experie...

  18. Tactile Feedback for Above-Device Gesture Interfaces

    OpenAIRE

    Freeman, Euan; Brewster, Stephen; Lantz, Vuokko

    2014-01-01

    Above-device gesture interfaces let people interact in the space above mobile devices using hand and finger movements. For example, users could gesture over a mobile phone or wearable without having to use the touchscreen. We look at how above-device interfaces can also give feedback in the space over the device. Recent haptic and wearable technologies give new ways to provide tactile feedback while gesturing, letting touchless gesture interfaces give touch feedback. In this paper we take a f...

  19. Tactile outline graphics for people who are visually impaired

    OpenAIRE

    Petrič, Ajda

    2013-01-01

    Tactile outline graphics are an important means for the blind and visually impaired. The grahics help to complete the images and contribute to understand special notions which are directly unavailable. Spreading the material which is primarily designed for the blind and visually impaired, contribute to indirect public awarness-rising how to communicate correctly with such people. More knowledge enables to the blind and visually impaired to the social integration, awarness-rising of the correc...

  20. Towards quantitative modelling of surface deformation of polymer micro-structures under tactile scanning measurement

    International Nuclear Information System (INIS)

    Contact stylus-based surface profilometry is capable of topography measurement whilst being independent of the physical, electrical and optical properties of the materials under test, and has therefore become an indispensable tool for dimensional measurement of transparent specimens. However, large measurement deviations will appear when soft specimens, especially specimens made of polymers, are measured by contact stylus profilometry. In this paper the surface deformation behaviour of two polymers for molding and one photoresist, i.e. Ormocomp, Ormoclad and SU-8, under different tactile measurement conditions have been experimentally investigated. An empirical analytical model is hereby proposed for the prediction of surface deformation of soft specimens under tactile (sliding) contact. Preliminary experimental results demonstrate that the proposed five-parameter model is applicable for describing the deformation behaviour of these thermoplastic materials under the scanning speed ranging from 2 to 200 μm s−1 and the probing force varying from 5 to 500 μN. In addition, thanks to quantitative topographical measurements of the layer thickness of the aforementioned photoresists, the scratch behaviour and the time-dependent mechanical properties of these materials have also been experimentally determined. (paper)

  1. Evaluation of a compound eye type tactile endoscope

    Science.gov (United States)

    Yoshimoto, Kayo; Yamada, Kenji; Sasaki, Nagisa; Takeda, Maki; Shimizu, Sachiko; Nagakura, Toshiaki; Takahashi, Hideya; Ohno, Yuko

    2013-03-01

    Minimally invasive surgical techniques for endoscope become widely used, for example, laparoscopic operation, NOTES (Natural Orifice Translumenal Endoscopic Surgery), robotic surgery and so on. There are so many demand and needs for endoscopic diagnosis. Especially, palpation is most important diagnosis on any surgery. However, conventional endoscopic system has no tactile sensibility. There are many studies about tactile sensor for medical application. These sensors can measure object at a point. It is necessary to sense in areas for palpation. To overcome this problem, we propose compound eye type tactile endoscope. The proposed system consists of TOMBO (Thin Observation Module by Bound Optics) and clear silicon rubber. Our proposed system can estimate hardness of target object by measuring deformation of a projected pattern on the silicon rubber. The purpose of this study is to evaluate the proposed system. At first, we introduce approximated models of the silicone and the object. We formulate the stiffness of object, the deformation of silicone, and the whole object. We investigate the accuracy of measured silicone's lower surface for deformation of silicone by prototype system. Finally, we evaluate the calculated stiffness of the soft object.

  2. 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

  3. Cross-modal tactile-taste interactions in food evaluations.

    Science.gov (United States)

    Slocombe, B G; Carmichael, D A; Simner, J

    2016-07-29

    Detecting the taste components within a flavoured substance relies on exposing chemoreceptors within the mouth to the chemical components of ingested food. In our paper, we show that the evaluation of taste components can also be influenced by the tactile quality of the food. We first discuss how multisensory factors might influence taste, flavour and smell for both typical and atypical (synaesthetic) populations and we then present two empirical studies showing tactile-taste interactions in the general population. We asked a group of non-synaesthetic adults to evaluate the taste components of flavoured food substances, whilst we presented simultaneous cross-sensory visuo-tactile cues within the eating environment. Specifically, we presented foodstuffs between subjects that were otherwise identical but had a rough versus smooth surface, or were served on a rough versus smooth serving-plate. We found no effect of the serving-plate, but we found the rough/smoothness of the foodstuff itself significantly influenced perception: food was rated as significantly more sour if it had a rough (versus smooth) surface. In modifying taste perception via ostensibly unrelated dimensions, we demonstrate that the detection of tastes within flavours may be influenced by higher level cross-sensory cues. Finally, we suggest that the direction of our cross-sensory associations may speak to the types of hedonic mapping found both in normal multisensory integration, and in the unusual condition of synaesthesia. PMID:26169315

  4. 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

    2011-11-10

    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. PMID:21976021

  5. Tactile book as one of tools for visually impaired children development

    OpenAIRE

    FLÍČKOVÁ, Radka

    2013-01-01

    This bachelor´s thesis deals with the topic of tactile books as means of the development of a child with visual impairments. Its theoretical part is divided into four chapters which handle an individual with visual impairments, classification of people with visual impairments, specific development of a child of preschool age with this kind of impairment, tactile viewing, tyflographics and production of books with tactile illustrations. The main aim of my thesis was to find out the opinions of...

  6. Gaze-dependent spatial updating of tactile targets in a localization task

    Directory of Open Access Journals (Sweden)

    StefanieMueller

    2014-02-01

    Full Text Available There is concurrent evidence that visual reach targets are represented with respect to gaze. For tactile reach targets, we previously showed that an effector movement leads to a shift from a gaze-independent to a gaze-dependent reference frame. Here we aimed to unravel the influence of effector movement (gaze shift on the reference frame of tactile stimuli using a spatial localization task (yes/no paradigm. We assessed how gaze direction (fixation left/right alters the perceived spatial location (point of subjective equality of sequentially presented tactile standard and visual comparison stimuli while effector movement (gaze fixed/shifted and stimulus order (vis-tac/tac-vis were varied. In the fixed-gaze condition, subjects maintained gaze at the fixation site throughout the trial. In the shifted-gaze condition, they foveated the first stimulus, then made a saccade toward the fixation site where they held gaze while the second stimulus appeared. Only when an effector movement occurred after the encoding of the tactile stimulus (shifted-gaze, tac-vis, gaze similarly influenced the perceived location of the tactile and the visual stimulus. In contrast, when gaze was fixed or a gaze shift occurred before encoding of the tactile stimulus, gaze differentially affected the perceived spatial relation of the tactile and the visual stimulus suggesting gaze-dependent coding of only one of the two stimuli. Consistent with previous findings this implies that visual stimuli vary with gaze irrespective of whether gaze is fixed or shifted. However, a gaze-dependent representation of tactile stimuli seems to critically depend on an effector movement (gaze shift after tactile encoding triggering spatial updating of tactile targets in a gaze-dependent reference frame. Together with our recent findings on tactile reaching, the present results imply similar underlying reference frames for tactile spatial perception and action.

  7. Measurement Principles of Optical Three-Axis Tactile Sensor and its Application to Robotic Fingers System

    OpenAIRE

    Yussof, Hanafiah; Takata, Jumpei; Ohka, Masahiro

    2008-01-01

    In this research we developed the original hemispherical shaped optical three-axis tactile sensor system to mount on robotic fingers. The tactile sensor is capable of acquiring normal and shearing forces, which are the most important sensing elements in object manipulation tasks. This tactile sensor is designed in a hemispherical dome shape that consists of an array of sensing elements. This shape is to mimics the structure of human fingertips for easy compliance with various shapes of object...

  8. Virtual Surface Characteristics of a Tactile Display Using Magneto-Rheological Fluids

    Directory of Open Access Journals (Sweden)

    Chul-Hee Lee

    2011-03-01

    Full Text Available Virtual surface characteristics of tactile displays are investigated to characterize the feeling of human touch for a haptic interface application. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR fluid has been developed. Tactile display devices simulate the finger’s skin to feel the sensations of contact such as compliance, friction, and topography of the surface. Thus, the tactile display can provide information on the surface of an organic tissue to the surgeon in virtual reality. In order to investigate the compliance feeling of a human finger’s touch, normal force responses of a tactile display under various magnetic fields have been assessed. Also, shearing friction force responses of the tactile display are investigated to simulate the action of finger dragging on the surface. Moreover, different matrix arrays of magnetic poles are applied to form the virtual surface topography. From the results, different tactile feelings are observed according to the applied magnetic field strength as well as the arrays of magnetic poles combinations. This research presents a smart tactile display technology for virtual surfaces.

  9. Cross-Modal Sensory Integration of Visual-Tactile Motion Information: Instrument Design and Human Psychophysics

    Directory of Open Access Journals (Sweden)

    Alice M. K. Wong

    2013-05-01

    Full Text Available Information obtained from multiple sensory modalities, such as vision and touch, is integrated to yield a holistic percept. As a haptic approach usually involves cross-modal sensory experiences, it is necessary to develop an apparatus that can characterize how a biological system integrates visual-tactile sensory information as well as how a robotic device infers object information emanating from both vision and touch. In the present study, we develop a novel visual-tactile cross-modal integration stimulator that consists of an LED panel to present visual stimuli and a tactile stimulator with three degrees of freedom that can present tactile motion stimuli with arbitrary motion direction, speed, and indentation depth in the skin. The apparatus can present cross-modal stimuli in which the spatial locations of visual and tactile stimulations are perfectly aligned. We presented visual-tactile stimuli in which the visual and tactile directions were either congruent or incongruent, and human observers reported the perceived visual direction of motion. Results showed that perceived direction of visual motion can be biased by the direction of tactile motion when visual signals are weakened. The results also showed that the visual-tactile motion integration follows the rule of temporal congruency of multi-modal inputs, a fundamental property known for cross-modal integration.

  10. The effects of intensive bimanual training with and without tactile training on tactile function in children with unilateral spastic cerebral palsy: A pilot study

    Science.gov (United States)

    Kuo, Hsing-Ching; Gordon, Andrew M.; Henrionnet, Aline; Hautfenne, Sylvie; Friel, Kathleen M.; Bleyenheuft, Yannick

    2016-01-01

    Children with unilateral spastic cerebral palsy (USCP) often have tactile impairments. Intensive bimanual training improves the motor abilities, but the effects on the sensory system have not been studied. Here we compare the effects of bimanual training with and without tactile training on tactile impairments. Twenty children with USCP (6–15.5 years; MACS: I–III) were randomized to receive either bimanual therapy (HABIT) or HABIT + tactile training (HABIT + T). All participants received 82 h of standardized HABIT. In addition 8 sessions of 1 h were provided to both groups. The HABIT + T group received tactile training (without vision) using materials of varied shapes and textures. The HABIT group received training with the same materials without tactile directed training (full vision). Primary outcomes included grating orientation task/GOT and stereognosis. Secondary outcomes included two-point discrimination/TPD, Semmes-Weinstein monofilaments/SWM. The GOT improved in both groups after training, while stereognosis of the more-affected hand tended to improve (but p = 0.063). No changes were found in the TPD and the SWM. There were no group × test interactions for any measure. We conclude tactile spatial resolution can improve after bimanual training. Either intensive bimanual training alone or incorporation of materials with a diversity of shapes/textures may drive these changes. PMID:26698408

  11. 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

  12. 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...

  13. 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 pas

  14. 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

    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...

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

    Science.gov (United States)

    Tezuka, Mayuko; Kitamura, Norihide; Tanaka, Kohei; Miki, Norihisa

    2016-01-01

    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. PMID:26845336

  16. 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.

  17. Tactile torso display as countermeasure to reduce night vision goggles induced drift

    NARCIS (Netherlands)

    Erp, J.B.F. van; Veltman, J.A.; Veen, H.A.H.C. van; Oving, A.B.

    2003-01-01

    The degraded visual infoflllation when hovering with Night Vision Goggles may induce drift that is not noticed by the pilot. We tested the possibilities of counteracting these effects by using a tactile torso display. The display consisted of 64 vibro-tactile elements and presented infoflllation on

  18. Design and Performance of a Low-Cost Telemetric Laparoscopic Tactile Grasper.

    Science.gov (United States)

    Schostek, Sebastian; Zimmermann, Melanie; Schurr, Marc O; Prosst, Ruediger L

    2016-06-01

    Tactile feedback is completely lost in laparoscopic surgery, which would provide information about tissue compliance, texture, structural features, and foreign bodies. We developed a system with artificial tactile feedback for laparoscopic surgery that consists of a telemetric tactile laparoscopic grasper, a remote PC with customized software, and a commercial video-mixer. A standard, nonsensorized laparoscopic grasper was customized to allow the integration of a tactile sensor and its electronics. The tactile sensor and the electronics module were designed to be detachable from the instrument. These parts are lightweight and wireless, thus not impeding the use of the device as surgical instrument. The remaining system components used to generate visualization of the tactile data do not influence the workflow in the operating room. The overall system design of the described instrumentation allows for easy implementation in an operating room environment. The fabrication of the tactile sensor is relatively easy and the production costs are low. With this telemetric laparoscopic grasper instrument, systematic preclinical studies can be performed in which surgeons execute surgical tasks that are derived from clinical reality. The experience gained from these investigations could then be used to define the requirements for any further development of artificial tactile feedback systems. PMID:26546367

  19. Tactile stimulation accelerates behavioral responses to visual stimuli through enhancement of occipital gamma-band activity

    NARCIS (Netherlands)

    Bauer, M.; Oostenveld, R.; Fries, P.

    2009-01-01

    We investigated how responses of occipital cortex to visual stimuli are modulated by simultaneously presented tactile stimuli. Magnetoencephalography was recorded while subjects performed a simple reaction time task. Presence of a task-irrelevant tactile stimulus leads to faster behavioral responses

  20. Enjoyment of tactile play is associated with lower food neophobia in preschool children.

    Science.gov (United States)

    Coulthard, Helen; Thakker, Dipti

    2015-07-01

    Previous research has shown that parental reports of food neophobia and tactile sensitivity are associated with lower fruit and vegetable (F/V) intake in children. This study aimed to pilot a behavioral observation measure of tactile play in young children. The primary aim of the study was to see whether children's enjoyment of tactile play was associated with higher F/V consumption, as well as lower food neophobia. Seventy 2- to 5-year-old children (37 males and 33 females) and their parents were recruited through children's centers in the Leicester region of the United Kingdom during July to October 2012. Children's engagement in two tactile play tasks using sticky foods (mashed potatoes and vegetarian gelatin) was observed and rated by both the researcher and parent. Parents were asked to complete a series of questionnaires measuring F/V consumption, food neophobia, and sensory processing. It was found that lower child food neophobia was significantly related to enjoyment of tactile play, whereas child F/V consumption was associated with parental F/V consumption, but not enjoyment of tactile play. The findings strengthen the idea that tactile processing may be associated with the acceptance of food variety, but not the total amount of F/V consumed. Additional research is indicated to determine whether tactile play tasks can be used to lower child food neophobia. PMID:25935569

  1. 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…

  2. Visuo-tactile interactions in the congenitally deaf: A behavioral and event-related potential study

    Directory of Open Access Journals (Sweden)

    Nadine Hauthal

    2015-01-01

    Full Text Available Auditory deprivation is known to be accompanied by alterations in visual processing. Yet not much is known about tactile processing and the interplay of the intact sensory modalities in the deaf. We presented visual, tactile, and visuo-tactile stimuli to congenitally deaf and hearing individuals in a speeded detection task. Analyses of multisensory responses showed a redundant signals effect that was attributable to a coactivation mechanism in both groups, although the redundancy gain was less in the deaf. In hearing but not deaf participants, N200 latencies of somatosensory event-related potentials were modulated by simultaneous visual stimulation. In deaf but not hearing participants, however, there was a modulation of N200 latencies of visual event-related potentials due to simultaneous tactile stimulation. A comparison of unisensory responses between groups revealed larger N200 amplitudes for visual and shorter N200 latencies for tactile stimuli in the deaf. P300 amplitudes in response to both stimuli were larger in deaf participants. The differences in visual and tactile processing between deaf and hearing participants, however, were not reflected in behavior. The electroencephalography (EEG results suggest an asymmetry in visuo-tactile interactions between deaf and hearing individuals. Visuo-tactile enhancements could neither be fully explained by perceptual deficiency nor by inverse effectiveness. Instead, we suggest that results might be explained by a shift in the relative importance of touch and vision in deaf individuals.

  3. 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 embodi

  4. 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

  5. A microfabricated strain gauge array on polymer substrate for tactile neuroprostheses in rats

    Science.gov (United States)

    Beygi, M.; Mutlu, S.; Güçlü, B.

    2016-08-01

    In this study, we present the design, microfabrication and characterization of a tactile sensor system which can be used for sensory neuroprostheses in rats. The sensor system consists of an array of 2  ×  7 cells, each of which has a series combination of four strain gauges. Each group of four strain gauges is placed around a square membrane with a size of 2.5  ×  2.5 mm2. Unlike most common tactile sensors based on silicon substrates, we used 3D-printed polylactic acid as a substrate, because it is not brittle, and under local extremes, it would prevent the catastrophic failure of all cells. The strain gauges were fabricated by depositing and patterning a 50 nm thick aluminum (Al) film on a polyimide sheet with a thickness of 0.125 mm. Polydimethylsiloxane (PDMS) elastomer was bonded on the top surface of the PI membrane. The PDMS layer was prepared in two different thicknesses, 1.2 and 1.7 mm, to investigate its effect on the static response of the sensor. The sensitivity and the maximum allowable force, corresponding to the maximum deformation of 0.9 mm at the center of each cell, changed based on the thickness of the PDMS layer. Sensor cells operated linearly up to 3 N with an average sensitivity of 200 mΩ N‑1 (0.7 Ω mm‑1) for 1.2 mm thick PDMS. These values changed to 4 N and 70 mΩ N‑1 (0.3 Ω mm‑1), respectively, for 1.7 mm thick PDMS. The nonlinearity was less than 3%. The cells had low cross-talk (~5 mΩ N‑1 and 0.02 Ω mm‑1) relative to the average sensitivity. Additionally, the dynamic response of the sensor was characterized at several frequencies by using a vibrotactile stimulation system previously designed for psychophysics experiments. The sensor was also tested inside the rat conditioning chamber to demonstrate the relevant signals in a tactile neuroprosthesis.

  6. High Resolution Tactile Sensors for Curved Robotic Fingertips

    DEFF Research Database (Denmark)

    Drimus, Alin; Jankovics, Vince; Gorsic, Matija;

    2014-01-01

    ]. For humans, extracting high level information from touch provides a better understanding of the objects manipulated while for insects it is essential for locomotion[3]. While robot designers have been using vision systems to provide the robot with information about its surroundings, this is not always......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...

  7. 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

  8. 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. PMID:21038960

  9. Graphesthesia: a test of graphemic movement representations or tactile imagery?

    Science.gov (United States)

    Drago, V; Foster, P S; Edward, D; Wargovich, B; Heilman, K M

    2010-01-01

    Patients with corticobasal degeneration (CBG) often demonstrate agraphesthesia in the same hand they demonstrate apraxia. To recognize letters written in their hand subjects can develop a spatial representation and access graphemic representations. Alternatively, people can use movement working memory and match movement patterns to stored letter movement representations. To learn the method normally used without vision, normal subjects (12) had letters written on their palm either in the normal manner or in a reverse direction. If letters written on the hand are recognized by their spatial features (as when visually reading) direction should not influence letter recognition, but if letters written on the hand are recognized by movement patterns, then in the reverse condition recognition should be impaired. When letters were written normally there were no differences in error between the tactile and visual modality. When letters were written in reverse, however, normal subjects made more errors in the tactile than visual condition. Normally, people identify letters written on their hand by covertly copying (mirroring) the examiner and then access letter movement representations. This might explain why patients with CBG often have agraphesthesia associated with apraxia. PMID:19796443

  10. A miniaturized and flexible optoelectronic sensing system for tactile skin

    Science.gov (United States)

    Ascari, L.; Corradi, P.; Beccai, L.; Laschi, C.

    2007-11-01

    This paper describes the development of a hybrid sensing module consisting of a general purpose electro-optical converter and three MEMS force sensors integrated into flexible substrates for tactile skin applications. The features of the converter, namely its flexible and thin substrate and small dimensions, programmability, optical coding and transmission of the information allow this versatile device to host different sensors, locally preprocess signals, translate this diverse information into a 'common language', and transmit it in a parallel, efficient and robust way to the processing unit. After discussing the major technical requirements, the design of the sensing, electrical and optical subsystems is illustrated, as well as the whole process for the module fabrication. A first characterization of a working prototype, hosting three MEMS force sensors and nine independent optical channels was performed. The global performance in terms of sensitivity, bandwidth and spatial sensing resolution make the presented module suitable to be used as basic element of a complete tactile system, conceived for robotic grasping and manipulation. Several solutions for mass production, improved optical properties and more efficient optical transmission are discussed.

  11. Multisensory numerosity judgments for visual and tactile stimuli.

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2007-05-01

    To date, numerosity judgments have been studied only under conditions of unimodal stimulus presentation. It is therefore unclear whether the same limitations on correctly reporting the number of unimodal visual or tactile stimuli presented in a display might be expected under conditions in which participants have to count stimuli presented simultaneously in two or more different sensory modalities. In Experiment 1, we investigated numerosity judgments using both unimodal and bimodal displays consisting of one to six vibrotactile stimuli (presented over the body surface) and one to six visual stimuli (seen on the body via mirror reflection). Participants had to count the number of stimuli regardless of their modality of presentation. Bimodal numerosity judgments were significantly less accurate than predicted on the basis of an independent modality-specific resources account, thus showing that numerosity judgments might rely on a unitary amodal system instead. The results of a second experiment demonstrated that divided attention costs could not account for the poor performance in the bimodal conditions of Experiment 1. We discuss these results in relation to current theories of cross-modal integration and to the cognitive resources and/or common higher order spatial representations possibly accessed by both visual and tactile stimuli. PMID:17727102

  12. Setup of a high-precision profilometer and comparison of tactile and optical measurements of standards

    International Nuclear Information System (INIS)

    Both optical and tactile probes are often used in dimensional metrology applications, especially for roughness, form, thickness and surface profile measurements. To perform such kinds of measurements with a nanometre-level of accuracy (∼30 nm), Laboratoire National de Métrologie et d’Essais (LNE) has developed a new high-precision machine. The architecture of the machine contains a short and stable metrology frame dissociated from the supporting frame. It perfectly respects the Abbe principle. The metrology loop supports reference laser interferometers and is equipped either with an optical probe or a tactile probe of nanometric resolution and linear residuals. The machine allows in situ calibration of the measuring optical and tactile probes by comparison to the laser interferometer measurements, considered as a reference. In this paper, both architecture and operation of the LNE's high-precision profilometer are detailed. A brief comparison of the behaviour (linear residuals) of the confocal chromatic and tactile probes is presented. Optical and tactile scanning of V-grooves artefacts with 75, 24, 7.5, 2.4, 0.75 and 0.24 µm depths are illustrated and discussed. In addition, a comparison between optical, tactile and atomic force microscopy measurements on a VLSI SHS 880-QC is also performed. Finally, a comparison of an optical and tactile scanning of optical aspherical lens with a polymer coating is presented and discussed. (paper)

  13. Feeling music: integration of auditory and tactile inputs in musical meter perception.

    Directory of Open Access Journals (Sweden)

    Juan Huang

    Full Text Available Musicians often say that they not only hear, but also "feel" music. To explore the contribution of tactile information in "feeling" musical rhythm, we investigated the degree that auditory and tactile inputs are integrated in humans performing a musical meter recognition task. Subjects discriminated between two types of sequences, 'duple' (march-like rhythms and 'triple' (waltz-like rhythms presented in three conditions: 1 Unimodal inputs (auditory or tactile alone, 2 Various combinations of bimodal inputs, where sequences were distributed between the auditory and tactile channels such that a single channel did not produce coherent meter percepts, and 3 Simultaneously presented bimodal inputs where the two channels contained congruent or incongruent meter cues. We first show that meter is perceived similarly well (70%-85% when tactile or auditory cues are presented alone. We next show in the bimodal experiments that auditory and tactile cues are integrated to produce coherent meter percepts. Performance is high (70%-90% when all of the metrically important notes are assigned to one channel and is reduced to 60% when half of these notes are assigned to one channel. When the important notes are presented simultaneously to both channels, congruent cues enhance meter recognition (90%. Performance drops dramatically when subjects were presented with incongruent auditory cues (10%, as opposed to incongruent tactile cues (60%, demonstrating that auditory input dominates meter perception. We believe that these results are the first demonstration of cross-modal sensory grouping between any two senses.

  14. The cognitive and neural correlates of "tactile consciousness": a multisensory perspective.

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2008-03-01

    People's awareness of tactile stimuli has been investigated in far less detail than their awareness of stimuli in other sensory modalities. In an attempt to fill this gap, we provide an overview of studies that are pertinent to the topic of tactile consciousness. We discuss the results of research that has investigated phenomena such as "change blindness", phantom limb sensations, and numerosity judgments in tactile perception, together with the results obtained from the study of patients affected by deficits that can adversely affect tactile perception such as neglect, extinction, and numbsense. The similarities as well as some of the important differences that have emerged when visual and tactile conscious information processing have been compared using similar experimental procedures are highlighted. We suggest that conscious information processing in the tactile modality cannot be separated completely from the more general processing of spatial information in the brain. Finally, the importance of considering tactile consciousness within the larger framework of multisensory information processing is also discussed. PMID:17398116

  15. Visuo-tactile interactions in the congenitally deaf: a behavioral and event-related potential study.

    Science.gov (United States)

    Hauthal, Nadine; Debener, Stefan; Rach, Stefan; Sandmann, Pascale; Thorne, Jeremy D

    2014-01-01

    Auditory deprivation is known to be accompanied by alterations in visual processing. Yet not much is known about tactile processing and the interplay of the intact sensory modalities in the deaf. We presented visual, tactile, and visuo-tactile stimuli to congenitally deaf and hearing individuals in a speeded detection task. Analyses of multisensory responses showed a redundant signals effect that was attributable to a coactivation mechanism in both groups, although the redundancy gain was less in the deaf. In line with these behavioral results, on a neural level, there were multisensory interactions in both groups that were again weaker in the deaf. In hearing but not deaf participants, somatosensory event-related potential N200 latencies were modulated by simultaneous visual stimulation. A comparison of unisensory responses between groups revealed larger N200 amplitudes for visual and shorter N200 latencies for tactile stimuli in the deaf. Furthermore, P300 amplitudes were also larger in the deaf. This group difference was significant for tactile and approached significance for visual targets. The differences in visual and tactile processing between deaf and hearing participants, however, were not reflected in behavior. Both the behavioral and electroencephalography (EEG) results suggest more pronounced multisensory interaction in hearing than in deaf individuals. Visuo-tactile enhancements could not be explained by perceptual deficiency, but could be partly attributable to inverse effectiveness. PMID:25653602

  16. 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.

  17. Acute aerobic exercise enhances attentional modulation of somatosensory event-related potentials during a tactile discrimination task.

    Science.gov (United States)

    Popovich, Christina; Staines, W Richard

    2015-03-15

    Neuroimaging research has shown that acute bouts of moderate intensity aerobic exercise can enhance attention-based neuronal activity in frontal brain regions, namely in the prefrontal cortex (PFC), as well as improve cognitive performance. The circuitry of the PFC is complex with extensive reciprocal corticocortical and thalamocortical connections, yet it remains unclear if aerobic exercise can also assist attentional control over modality-specific sensory cortices. To test this, we used a tactile discrimination task to compare tactile event-related potentials (ERPs) prior to and following an acute bout of moderate intensity aerobic exercise. We hypothesized that exercise preceding performance of the task would result in more efficient sensory gating of irrelevant/non-attended and enhancement of relevant/attended sensory information, respectively. Participants received vibrotactile stimulation to the second and fifth digit on the left hand and reported target stimuli on one digit only. ERP amplitudes for the P50, P100, N140 and long latency positivity (LLP) were quantified for attended and non-attended trials at FC4, C4, CP4 and P4 while P300 amplitudes were quantified in response to attended target stimuli at electrodes FCZ, CZ and CPZ. Results showed no effect of attention on the P50, however, both P100 and LLP amplitudes were significantly greater during attended, task-relevant trials, while the N140 was enhanced for non-attended, task-irrelevant stimuli. Moreover, unattended N140 amplitudes over parietal sites contralateral to stimulation were significantly greater post-exercise versus pre-exercise, while LLP modulation varied with greater unattended amplitudes post-exercise over frontal sites and greater attended amplitudes post-exercise over parietal sites. These results suggest that a single session of moderate intensity aerobic exercise facilitated the sensory gating of task-irrelevant tactile stimuli so that relevant sensory signals could be enhanced at

  18. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a “natural” grasping task induces pantomime-like grasps

    OpenAIRE

    Whitwell, Robert L.; Ganel, Tzvi; Byrne, Caitlin M.; Goodale, Melvyn A.

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. “Natural” prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object (“haptics-based object information”) once contact with the object has been made. Natural and simulated (...

  19. Tactile thresholds are preserved yet complex sensory function is impaired over the lumbar spine of chronic non-specific low back pain patients. A preliminary investigation

    OpenAIRE

    Wand, BM; Di Pietro, FS; George, PJ; O'Connell, NE

    2010-01-01

    Objectives: To investigate impairments in sensory function in chronic non-specific low back pain patients and the relationship between any impairment and the clinical features of the condition. Design: A cross-sectional case-control study. Setting: Laboratory based study. Participants: Nineteen chronic non-specific low back pain patients and nineteen healthy controls. Main Outcome measures: Tactile threshold, two point discrimination distance and accuracy at a task involving recognizing lett...

  20. Tactile Sensors for the NASA/DARPA Robonaut

    Science.gov (United States)

    Martin, Toby B.; Diftler, Myron; Ambrose, Robert O.; Platt, Robert, Jr.; Butzer, Melissa

    2004-01-01

    Tactile sensors are providing the foundation for developing autonomous grasping skills for the NASA/DARPA Robonaut, a dexterous humanoid robot. The sensors originally developed for the Utah/MIT hand are now incorporated into a rugged glove for Robonaut. These custom gloves compliment the human like dexterity available in the Robonaut hands. The sensors and gloves are discussed showing a progression in using advanced materials and construction techniques to enhance sensitivity and overall sensor coverage. The force data provided by the gloves can be used to improve dexterous, tool and power grasping primitives. Experiments with the latest gloves focus on the use of tools, specifically a power drill used to approximate an astronaut's torque tool.

  1. Laser-induced thermoelastic effects can evoke tactile sensations

    Science.gov (United States)

    Jun, Jae-Hoon; Park, Jong-Rak; Kim, Sung-Phil; Min Bae, Young; Park, Jang-Yeon; Kim, Hyung-Sik; Choi, Seungmoon; Jung, Sung Jun; Hwa Park, Seung; Yeom, Dong-Il; Jung, Gu-In; Kim, Ji-Sun; Chung, Soon-Cheol

    2015-06-01

    Humans process a plethora of sensory information that is provided by various entities in the surrounding environment. Among the five major senses, technology for touch, haptics, is relatively young and has relatively limited applications largely due to its need for physical contact. In this article, we suggest a new way for non-contact haptic stimulation that uses laser, which has potential advantages such as mid-air stimulation, high spatial precision, and long working distance. We demonstrate such tactile stimulation can be enabled by laser-induced thermoelastic effects by means of physical and perceptual studies, as well as simulations. In the physical study, the mechanical effect of laser on a human skin sample is detected using low-power radiation in accordance with safety guidelines. Limited increases (subjective reports of the non-nociceptive sensation of laser stimuli.

  2. 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.

  3. 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

  4. Contribution à la Conception et à la Réalisation d'Interfaces Tactiles Portables pour les Déficients Visuels

    OpenAIRE

    Velazquez, Ramiro

    2006-01-01

    Ce travail de thèse porte sur la conception et la réalisation d'un nouveau concept d'interface tactile compacte, portable, légère, à faible coût et à haute résolution. Cette interface, dédiée aux personnes aveugles et malvoyantes, est à la base d'une nouvelle approche d'aide à la mobilité basée sur la substitution/suppléance visuo-tactile.En s'appuyant sur la psychophysiologie du sens du toucher associée à une technologie d'actionnement de type Alliages à Mémoire de Forme (AMF), un dispositif...

  5. Integrating Tactile and Force Feedback for Highly Dynamic Tasks : Technological, Experimental and Epistemological Aspects

    OpenAIRE

    Khatchatourov, Armen; Castet, Julien; Florens, Jean-Loup; Luciani, Annie; Lenay, Charles

    2009-01-01

    For hand-object interaction in real situations the interplay between the local tactile interaction and force interaction seems to be very important. In current haptic interfaces, however, two different trends are present: force feedback devices which offer a permanent invariable grip and a resultant force, and tactile devices, which offer variable local patterns, often used for texture rendering. The purpose of the present work is to combine the two types of devices in a coherent manner. In t...

  6. Sensory information in perceptual-motor sequence learning: visual and/or tactile stimuli

    OpenAIRE

    Abrahamse, Elger L.; Lubbe, van der, S.; Verwey, Willem B.

    2009-01-01

    Sequence learning in serial reaction time (SRT) tasks has been investigated mostly with unimodal stimulus presentation. This approach disregards the possibility that sequence acquisition may be guided by multiple sources of sensory information simultaneously. In the current study we trained participants in a SRT task with visual only, tactile only, or bimodal (visual and tactile) stimulus presentation. Sequence performance for the bimodal and visual only training groups was similar, while bot...

  7. TACTILE RESPONSIVENESS PATTERNS AND THEIR ASSOCIATION WITH CORE FEATURES IN AUTISM SPECTRUM DISORDERS

    OpenAIRE

    Foss-Feig, Jennifer H.; Heacock, Jessica L.; Cascio, Carissa J.

    2012-01-01

    Autism spectrum disorders (ASD) are often associated with aberrant responses to sensory stimuli, which are thought to contribute to the social, communication, and repetitive behavior deficits that define ASD. However, there are few studies that separate aberrant sensory responses by individual sensory modality to assess modality-specific associations between sensory features and core symptoms. Differences in response to tactile stimuli are prevalent in ASD, and tactile contact early in infanc...

  8. Peripheral NMDA Receptors Mediate Antidromic Nerve Stimulation-Induced Tactile Hypersensitivity in the Rat

    OpenAIRE

    Jun Ho Jang; Taick Sang Nam; Jaebeom Jun; Se Jung Jung; Dong-Wook Kim; Joong Woo Leem

    2015-01-01

    We investigated the role of peripheral NMDA receptors (NMDARs) in antidromic nerve stimulation-induced tactile hypersensitivity outside the skin area innervated by stimulated nerve. Tetanic electrical stimulation (ES) of the decentralized L5 spinal nerve, which induced enlargement of plasma extravasation, resulted in tactile hypersensitivity in the L4 plantar dermatome of the hind-paw. When intraplantar (i.pl.) injection was administered into the L4 dermatome before ES, NMDAR and group-I meta...

  9. A generic approach for augmenting tactile diagrams with spatial non-speech sounds

    OpenAIRE

    Ramloll, R.; Brewster, S.A.

    2002-01-01

    Blind or visually impaired users typically access diagrams in the tactile medium. This paper describes TouchMelody, a system designed for augmenting such existing diagrams with 3D spatial auditory information to increase their usefulness, information content and reduce tactile clutter. The motivation for this system, an overview of its development and early experiences are presented. The two major technologies used are the Polhemus FASTRAK and the LakeDSP CP4 to facilitate the creation of a d...

  10. Design and evaluation of interactive audio-tactile maps for visually impaired people

    OpenAIRE

    Brock, Anke

    2015-01-01

    In order to overcome challenges related to orientation and mobility, visually impaired people need to know their environment. Tactile relief maps are generally used for exploring geographic information, but they retain significant limitations. Recent technological progress allows the development of interactive maps which overcome these limitations. We designed an accessible interactive map prototype composed by a multi-touch screen with tactile map overlay and speech output. It provided audit...

  11. Visual and spatial modulation of tactile extinction: behavioural and electrophysiological evidence

    OpenAIRE

    Chiara Francesca Sambo; Giuseppe eVallar; Paola eFortis; Roberta eRonchi; Lucio ePosteraro; Bettina eForster; Angelo eMaravita

    2012-01-01

    Crossing the hands over the midline reduces left tactile extinction to double simultaneous stimulation in right-brain-damaged patients, suggesting that spatial attentional biases toward the ipsilesional (right) side of space contribute to the patients' contralesional (left) deficit. We investigated (1) whether the position of the left hand, and its vision, affected processing speed of tactile stimuli, and (2) the electrophysiological underpinnings of the effect of hand position. (1) Four righ...

  12. Detection of fever in children emergency care: comparisons of tactile and rectal temperatures in Nigerian children

    OpenAIRE

    Okafor Olubukola O; Tongo Olukemi O; Orimadegun Adebola E; Akinbami Felix O; Akinyinka Olusegun O

    2010-01-01

    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 th...

  13. Tactile-dependant corticomotor facilitation is influenced by discrimination performance in seniors

    OpenAIRE

    Tremblay François; Master Sabah

    2010-01-01

    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, attentio...

  14. Biological and Physiological Markers of Tactile Sensorial Processing in Healthy Newborns

    OpenAIRE

    Gonçalves, MG; Caldeira-da-Silva, P

    2012-01-01

    The main objective of this review is to provide a descriptive analysis of the biological and physiological markers of tactile sensorial processing in healthy, full-term newborns. Research articles were selected according to the following study design criteria: (a) tactile stimulation for touch sense as an independent variable; (b) having at least one biological or physiological variable as a dependent variable; and (c) the group of participants were characterized as full-term and healthy newb...

  15. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a "natural" grasping task induces pantomime-like grasps.

    Science.gov (United States)

    Whitwell, Robert L; Ganel, Tzvi; Byrne, Caitlin M; Goodale, Melvyn A

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. "Natural" prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object ("haptics-based object information") once contact with the object has been made. Natural and simulated (pantomimed) forms of prehension are thought to recruit different cortical structures: patient DF, who has visual form agnosia following bilateral damage to her temporal-occipital cortex, loses her ability to scale her grasp aperture to the size of targets ("grip scaling") when her prehensile movements are based on a memory of a target previewed 2 s before the cue to respond or when her grasps are directed towards a visible virtual target but she is denied haptics-based information about the target. In the first of two experiments, we show that when DF performs real-time pantomimed grasps towards a 7.5 cm displaced imagined copy of a visible object such that her fingers make contact with the surface of the table, her grip scaling is in fact quite normal. This finding suggests that real-time vision and terminal tactile feedback are sufficient to preserve DF's grip scaling slopes. In the second experiment, we examined an "unnatural" grasping task variant in which a tangible target (along with any proxy such as the surface of the table) is denied (i.e., no terminal tactile feedback). To do this, we used a mirror-apparatus to present virtual targets with and without a spatially coincident copy for the participants to grasp. We compared the grasp kinematics from trials with and without terminal tactile feedback to a real-time-pantomimed grasping task (one without tactile feedback) in which participants visualized a copy of the visible target as instructed in our laboratory in the

  16. 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. PMID:19198849

  17. Are We Ready to Build a System for Assisting Blind People in Tactile Exploration of Bas-Reliefs?

    Science.gov (United States)

    Buonamici, Francesco; Carfagni, Monica; Furferi, Rocco; Governi, Lapo; Volpe, Yary

    2016-01-01

    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. PMID:27563906

  18. Now you feel both: Galvanic vestibular stimulation induces lasting improvements in the rehabilitation of chronic tactile extinction

    OpenAIRE

    Lena Schmidt; Kathrin S. Utz

    2013-01-01

    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. ...

  19. Now You Feel both: Galvanic Vestibular Stimulation Induces Lasting Improvements in the Rehabilitation of Chronic Tactile Extinction

    OpenAIRE

    Schmidt, Lena; Kathrin S. Utz; Depper, Lena; Adams, Michaela; Schaadt, Anna-Katharina; Reinhart, Stefan; Kerkhoff, Georg

    2013-01-01

    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....

  20. 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.

  1. 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.

  2. Research progress of functional magnetic resonance imaging in cross-modal activation of visual cortex during tactile perception

    International Nuclear Information System (INIS)

    An increasing amount of neuroimaging studies recently demonstrated activation of visual cortex in both blind and sighted participants when performing a variety of tactile tasks such as Braille reading and tactile object recognition, which indicates that visual cortex not only receives visual information, but may participate in tactile perception. To address these cross-modal changes of visual cortex and the neurophysiological mechanisms, many researchers conducted explosive studies using functional magnetic resonance imaging (fMRI) and have made some achievements. This review focuses on cross-modal activation of visual cortex and the underlying mechanisms during tactile perception in both blind and sighted individuals. (authors)

  3. 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.

  4. Tactile thermal oral stimulation increases the cortical representation of swallowing

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    Suntrup Sonja

    2009-06-01

    Full Text Available Abstract Background Dysphagia is a leading complication in stroke patients causing aspiration pneumonia, malnutrition and increased mortality. Current strategies of swallowing therapy involve on the one hand modification of eating behaviour or swallowing technique and on the other hand facilitation of swallowing with the use of pharyngeal sensory stimulation. Thermal tactile oral stimulation (TTOS is an established method to treat patients with neurogenic dysphagia especially if caused by sensory deficits. Little is known about the possible mechanisms by which this interventional therapy may work. We employed whole-head MEG to study changes in cortical activation during self-paced volitional swallowing in fifteen healthy subjects with and without TTOS. Data were analyzed by means of synthetic aperture magnetometry (SAM and the group analysis of individual SAM data was performed using a permutation test. Results Compared to the normal swallowing task a significantly increased bilateral cortical activation was seen after oropharyngeal stimulation. Analysis of the chronological changes during swallowing suggests facilitation of both the oral and the pharyngeal phase of deglutition. Conclusion In the present study functional cortical changes elicited by oral sensory stimulation could be demonstrated. We suggest that these results reflect short-term cortical plasticity of sensory swallowing areas. These findings facilitate our understanding of the role of cortical reorganization in dysphagia treatment and recovery.

  5. Cognition overrides orientation dependence in tactile viewpoint selection.

    Science.gov (United States)

    Hartcher-O'Brien, Jessica; Auvray, Malika

    2016-07-01

    Humans are capable of extracting spatial information through their sense of touch: when someone strokes their hand, they can easily determine stroke direction without visual information. However, when it comes to the coordinate system used to assign the spatial relations to the stimulation, it remains poorly understood how the brain selects the appropriate system for passive touch. In the study reported here, we investigated whether hand orientation can determine coordinate assignment to ambiguous tactile patterns, whether observers can cognitively override any orientation-driven perspectives on touch, and whether the adaptation transfers across body surfaces. Our results demonstrated that the orientation of the hand in the vertical plane determines the perspective taken: an external perspective is adopted when the hand faces the observer and a gaze-centred perspective is selected when the hand faces away. Participants were then adapted to a mirror-reversed perspective through training, and the results revealed that this adapted perspective holds for the adapted surface and generalises to non-adapted surfaces, including across the body midline. These results reveal plasticity in perspective taking which relies on low-level postural cues (hand orientation) but also on higher-order somatosensory processing that can override the low-level cues. PMID:26894892

  6. A Novel Tactile Force Probe for Tissue Stiffness Classification

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    Behafarid Darvish

    2009-01-01

    Full Text Available In this study, we have proposed a new type of tactile sensor that is capable of detecting the stiffness of soft objects. The sensor consists of a brass cylinder with an axial bore. An iron core can easily move inside the bore. Three peripheral bobbins were machined in the cylinder around which three coils have been wound. One of the coils was excited with an alternating current which caused a voltage to be induced in two other coils. A return spring was used to return the core to its initial position after it has been moved. The sensor was pressed against the surface of the object whose stiffness was going to be measured. The position of the core in this state was depended on the stiffness of the given object and the spring constant and was measured by measuring the change in the induced voltage in secondary coils. The proposed sensor was capable of measuring two contact parameters namely the applied force and the stiffness of the object. Using the data of this sensor, three different objects, made of polyurethane, silicon rubber and paraffin gel were discriminated. Thus, this sensor could be used in robot hands and minimally invasive surgery tools to improve their operation.

  7. 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.

  8. 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.

  9. Tactile stimulation during development alters the neuroanatomical organization of the optic nerve in normal rats.

    Science.gov (United States)

    Horiquini-Barbosa, Everton; Lachat, João-José

    2016-06-01

    This study was designed to investigate the progressive effect of tactile stimulation in the cytoarchitecture of the optic nerve of normal rats during early postnatal development. We used 36 male pups which were randomly assigned to either the tactile-stimulated group (TS-stimulation for 3 min, once a day, from postnatal day (P) 1 to 32) or the non-tactile-stimulated (NTS) group. Morphological analysis were performed to evaluate the alterations caused by tactile stimulation, and morphometric analysis were carried out to determine whether the observed changes in optic nerve cytoarchitecture were significantly different between groups and at three different ages (P18, P22, and P32), thereby covering the entire progression of development of the optic nerve from its start to its completion. The rats of both groups presented similar increase in body weight. The morphometric analysis revealed no difference in the astrocyte density between age-matched groups; however, the oligodendrocyte density of TS group was higher compared to the NTS at P22, and P32, but not at P18. The optic nerve of TS group showed an increase of blood vessels and a reduction of damage fiber density when compared to the age-matched pups of NTS. Taken together, these findings support the view that tactile stimulation, an enriching experience, can positively affects the neuroanatomy of the brain, modifying its cellular components by progressive morphological and morphometric changes. PMID:26879768

  10. 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.

  11. Sensitivity enhancement of a micro-scale biomimetic tactile sensor with epidermal ridges

    International Nuclear Information System (INIS)

    A microscale biomimetic tactile sensor with epidermal ridges is proposed to enhance the sensitivity of force detection. Guided by the principles of the human tactile perception mechanism, specifically the epidermal ridges, artificial epidermal ridges made of polydimethylsiloxane (PDMS) were designed and placed on micro-fabricated metal strain gauge arrays. A polyimide layer was fabricated to facilitate attachment between the metal and PDMS, so that patterned copper could be deposited on the polyimide to function as the strain gauges. The aspect ratio of the artificial epidermal ridges was optimized using material stability calculations and finite element method (FEM) simulations, and the optimal structure obtained was 400 µm in width and 110 µm in height. Experiments verified the effectiveness of enhancing the sensitivity of such a tactile sensor with the artificial epidermal ridges, in that the outputs of the strain gauges were 1.8 times more sensitive than those of a tactile sensor without ridges. The proposed artificial epidermal ridges are readily applicable to any developed tactile sensors for performance enhancement.

  12. A spatiotemporal signature of cortical pain relief by tactile stimulation: An MEG study.

    Science.gov (United States)

    Hayamizu, Mariko; Hagiwara, Koichi; Hironaga, Naruhito; Ogata, Katsuya; Hoka, Sumio; Tobimatsu, Shozo

    2016-04-15

    Recently, the cortical mechanisms of tactile-induced analgesia have been investigated; however, spatiotemporal characteristics have not been fully elucidated. The insular-opercular region integrates multiple sensory inputs, and nociceptive modulation by other sensory inputs occurs in this area. In this study, we focused on the insular-opercular region to characterize the spatiotemporal signature of tactile-induced analgesia using magnetoencephalography in 11 healthy subjects. Aδ (intra-epidermal electrical stimulation) inputs were modified by Aβ (mechanical tactile stimulation) selective stimulation, either independently or concurrently, to the right forearm. The optimal inter-stimulus interval (ISI) for cortical level modulation was determined after comparing the 40-, 60-, and 80-ms ISI conditions, and the calculated cortical arrival time difference between Aδ and Aβ inputs. Subsequently, we adopted a 60-ms ISI for cortical modulation and a 0-ms ISI for spinal level modulation. Source localization using minimum norm estimates demonstrated that pain-related activity was located in the posterior insula, whereas tactile-related activity was estimated in the parietal operculum. We also found significant inhibition of pain-related activity in the posterior insula due to cortical modulation. In contrast, spinal modulation was observed both in the posterior insula and parietal operculum. Subjective pain, as evaluated by the visual analog scale, also showed significant reduction in both conditions. Therefore, our results demonstrated that the multisensory integration within the posterior insula plays a key role in tactile-induced analgesia. PMID:26854558

  13. Lost in the move? Secondary task performance impairs tactile change detection on the body.

    Science.gov (United States)

    Gallace, Alberto; Zeeden, Sophia; Röder, Brigitte; Spence, Charles

    2010-03-01

    Change blindness, the surprising inability of people to detect significant changes between consecutively-presented visual displays, has recently been shown to affect tactile perception as well. Visual change blindness has been observed during saccades and eye blinks, conditions under which people's awareness of visual information is temporarily suppressed. In the present study, we demonstrate change blindness for suprathreshold tactile stimuli resulting from the execution of a secondary task requiring bodily movement. In Experiment 1, the ability of participants to detect changes between two sequentially-presented vibrotactile patterns delivered on their arms and legs was compared while they performed a secondary task consisting of either the execution of a movement with the right arm toward a visual target or the verbal identification of the target side. The results demonstrated that a motor response gave rise to the largest drop in perceptual sensitivity (as measured by changes in d') in detecting changes to the tactile display. In Experiment 2, we replicated these results under conditions in which the participants had to detect tactile changes while turning a steering wheel instead. These findings are discussed in terms of the role played by bodily movements, sensory suppression, and higher order information processing in modulating people's awareness of tactile information across the body surface. PMID:19647451

  14. VARIATIONS IN TACTILE SIGNING – THE CASE OF ONE-HANDED SIGNING

    Directory of Open Access Journals (Sweden)

    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.

  15. Effects of spatially correlated acoustic-tactile information on judgments of auditory circular direction

    Science.gov (United States)

    Cohen, Annabel J.; Lamothe, M. J. Reina; Toms, Ian D.; Fleming, Richard A. G.

    2002-05-01

    Cohen, Lamothe, Fleming, MacIsaac, and Lamoureux [J. Acoust. Soc. Am. 109, 2460 (2001)] reported that proximity governed circular direction judgments (clockwise/counterclockwise) of two successive tones emanating from all pairs of 12 speakers located at 30-degree intervals around a listeners' head (cranium). Many listeners appeared to experience systematic front-back confusion. Diametrically opposed locations (180-degrees-theoretically ambiguous direction) produced a direction bias pattern resembling Deutsch's tritone paradox [Deutsch, Kuyper, and Fisher, Music Percept. 5, 7992 (1987)]. In Experiment 1 of the present study, the circular direction task was conducted in the tactile domain using 12 circumcranial points of vibration. For all 5 participants, proximity governed direction (without front-back confusion) and a simple clockwise bias was shown for 180-degree pairs. Experiment 2 tested 9 new participants in one unimodal auditory condition and two bimodal auditory-tactile conditions (spatially-correlated/spatially-uncorrelated). Correlated auditory-tactile information eliminated front-back confusion for 8 participants and replaced the ``paradoxical'' bias for 180-degree pairs with the clockwise bias. Thus, spatially correlated audio-tactile location information improves the veridical representation of 360-degree acoustic space, and modality-specific principles are implicated by the unique circular direction bias patterns for 180-degree pairs in the separate auditory and tactile modalities. [Work supported by NSERC.

  16. Woven flexible textile structure for wearable power-generating tactile sensor array

    Science.gov (United States)

    Ahn, Yongho; Song, Seunghwan; Yun, Kwang-Seok

    2015-07-01

    In this paper, we propose and demonstrate a power-generating tactile sensor array in which an energy harvester and an array of tactile sensors are integrated in a single device. The device consists of rows and columns of piezoelectric straps woven on a mesh structure of elastic hollow tubes. The fabricated device, which includes 5 × 5 capacitive tactile sensors in an area of 9 × 9 cm2, is highly flexible and stretchable. When the device was stretched in a lateral direction, the maximum output voltage and power were measured as 51 V and 850 μW, respectively. In addition, the capacitance value employed as a signal for the tactile sensor operation was measured while applying a force vertically to the surface using a force gauge. The initial capacitance and sensitivity of a single cell employed as a tactile sensor were approximately 1.727 pF and 40 fF/N, respectively, within a force range of 2 N.

  17. Triboelectric active sensor array for self-powered static and dynamic pressure detection and tactile imaging.

    Science.gov (United States)

    Lin, Long; Xie, Yannan; Wang, Sihong; Wu, Wenzhuo; Niu, Simiao; Wen, Xiaonan; Wang, Zhong Lin

    2013-09-24

    We report an innovative, large-area, and self-powered pressure mapping approach based on the triboelectric effect, which converts the mechanical stimuli into electrical output signals. The working mechanism of the triboelectric active sensor (TEAS) was theoretically studied by both analytical method and numerical calculation to gain an intuitive understanding of the relationship between the applied pressure and the responsive signals. Relying on the unique pressure response characteristics of the open-circuit voltage and short-circuit current, we realize both static and dynamic pressure sensing on a single device for the first time. A series of comprehensive investigations were carried out to characterize the performance of the TEAS, and high sensitivity (0.31 kPa(-1)), ultrafast response time (<5 ms), long-term stability (30,000 cycles), as well as low detection limit (2.1 Pa) were achieved. The pressure measurement range of the TEAS was adjustable, which means both gentle pressure detection and large-scale pressure sensing were enabled. Through integrating multiple TEAS units into a sensor array, the as-fabricated TEAS matrix was capable of monitoring and mapping the local pressure distribution applied on the device with distinguishable spatial profiles. This work presents a technique for tactile imaging and progress toward practical applications of nanogenerators, providing potential solutions for accomplishment of artificial skin, human-electronic interfacing, and self-powered systems. PMID:23957827

  18. Insights into the Mechanical Behaviour of a Layered Flexible Tactile Sensor

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    Julián Castellanos-Ramos

    2015-10-01

    Full Text Available This paper shows realizations of a piezoresistive tactile sensor with a low cost screen-printing technology. A few samples were fabricated for different materials used as insulator between the conductive layers and as top layer or cover. Both can be used to tune the sensitivity of the sensor. However, a large influence is also observed of the roughness at the contact interface on the sensitivity and linearity of the output, as well as on mismatching between the outputs from different taxels. The roughness at the contact interface is behind the transduction principle of the sensor, but it also limits its performance if the wavelength of the roughness is comparable or even longer than the size of the contacts. The paper shows experimental results that confirm this relationship and discusses its consequences in sensor response related to the materials chosen for the insulator and the cover. Moreover, simulations with FEA tools and with simple models are used to support the discussions and conclusions obtained from the experimental data. This provides insights into the sensor behaviour that are shared by other sensors based on the same principle.

  19. Real-Time Gesture-Controlled Physical Modelling Music Synthesis with Tactile Feedback

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    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.

  20. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

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    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.

  1. 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…

  2. The role of fingerprints in the coding of tactile information probed with a biomimetic sensor

    CERN Document Server

    Scheibert, J; Prevost, A; Debrégeas, G; 10.1126/science.1166467

    2009-01-01

    In humans, the tactile perception of fine textures (spatial scale <200 micrometers) is mediated by skin vibrations generated as the finger scans the surface. To establish the relationship between texture characteristics and subcutaneous vibrations, a biomimetic tactile sensor has been designed whose dimensions match those of the fingertip. When the sensor surface is patterned with parallel ridges mimicking the fingerprints, the spectrum of vibrations elicited by randomly textured substrates is dominated by one frequency set by the ratio of the scanning speed to the interridge distance. For human touch, this frequency falls within the optimal range of sensitivity of Pacinian afferents, which mediate the coding of fine textures. Thus, fingerprints may perform spectral selection and amplification of tactile information that facilitate its processing by specific mechanoreceptors.

  3. Tactile perception of skin and skin cream by friction induced vibrations.

    Science.gov (United States)

    Ding, Shuyang; Bhushan, Bharat

    2016-11-01

    Skin cream smooths, softens, and moistens skin by altering surface roughness and tribological properties of skin. Sliding generates vibrations that activate mechanoreceptors located in skin. The brain interprets tactile information to identify skin feel. Understanding the tactile sensing mechanisms of skin with and without cream treatment is important to numerous applications including cosmetics, textiles, and robotics sensors. In this study, frequency spectra of friction force and friction induced vibration signals were carried out to investigate tactile perception by an artificial finger sliding on skin. The influence of normal load, velocity, and cream treatment time were studied. Coherence between friction force and vibration signals were found. The amplitude of vibration decreased after cream treatment, leading to smoother perception. Increasing normal load or velocity between contacting surfaces generated a smoother perception with cream treatment, but rougher perception without treatment. As cream treatment time increases, skin becomes smoother. The related mechanisms are discussed. PMID:27474814

  4. Visual capture of apparent limb position influences tactile temporal order judgments.

    Science.gov (United States)

    Gallace, Alberto; Spence, Charles

    2005-04-29

    Shore et al. [D.I. Shore, E. Spry, C. Spence, Spatial modulation of tactile temporal order judgments, Perception (submitted for publication)] recently demonstrated that people find it easier to judge which hand is touched first (in a tactile temporal order judgment task) when their hands are placed far apart rather than close together. In the present study, we used a mirror to manipulate the visually perceived distance between participants' hands, while holding the actual (i.e., proprioceptively-specified) distance between them constant. Participants were asked to determine which of two vibrotactile stimuli, one presented to either index finger using the method of constant stimuli, was presented first. Performance was significantly worse (i.e., the JND was larger) when the hands were perceived (due to the mirror reflection) as being close together rather than further apart. These results highlight the critical role that vision plays in influencing the conscious perception of the temporal order of tactile stimuli. PMID:15814201

  5. A case of tactile agnosia with a lesion restricted to the post-central gyrus

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    Estanol Bruno

    2008-01-01

    Full Text Available Tactile agnosia has been described after lesions of the primary sensory cortex but the exact location and extension of those lesions is not clear. We report the clinical features and imaging findings in a patient with an acute ischemic stroke restricted to the primary sensory area (S1. A 73-year-old man had a sudden onset of a left alien hand, without left hemiparesis. Neurological examination showed intact primary sensory functions, but impaired recognition of shape, size (macrogeometrical and texture (microgeometrical of objects; damage confined to the post-central gyrus, sparing the posterior parietal cortex was demonstrated on MRI. An embolic occlusion of the anterior parietal artery was suspected as mechanism of stroke. Tactile agnosia with impaired microgeometrical and macrogeometrical features′ recognition can result from a single lesion in the primary sensory cortex (S1 in the right parietal hemisphere, sparing other regions of the cerebral cortex which presumably participate in tactile object recognition.

  6. Fabrication of a wearable fabric tactile sensor produced by artificial hollow fiber

    International Nuclear Information System (INIS)

    An artificial-hollow-fiber structure as a new material for MEMS was developed and applied to a novel type of fabric tactile sensor. The artificial hollow fiber was fabricated by uniformly deposited metal and insulation layers on the surface of an elastic tube. A special rotating mechanism for uniformly depositing a metal layer on the tube surface during sputtering was developed. A rectangular-shaped fabric tactile sensor was produced by combining artificial hollow fibers and typical cotton yarns, like a cloth. The sensor can detect a contact force by measuring changes in capacitance at all intersection points of the artificial hollow fibers. Two different types of wearable-tactile-sensor glove, a patched type and a direct knit type, were also fabricated, and it was confirmed that both types can detect a normal load by measuring the capacitance change

  7. Development of a tactile sensing system using piezoelectric robot skin materials

    International Nuclear Information System (INIS)

    Since service robots perform their functions in close proximity to humans, they are much more likely than other types of robot to come into contact with humans. This means that safety regarding robot–human interaction is of particular concern and requires investigation. Existing tactile sensing methods are very effective at detecting external dangerous loadings; however, until now, they have been very expensive. Recently, a new type of self-sensing tactile technology for service robots has been introduced, which harnesses the piezoelectric effect of several robot skin materials. In these kinds of system, relatively cheap materials are used as sensors themselves. In this research, a robot system with a self-sensing tactile technology was developed using piezoelectric robot skin materials. The test results indicate that this type of system is appropriate for application to service robots. (paper)

  8. Enhancing Activity by Means of Tactile Symbols: A Study of a Heterogeneous Group of Pupils with Congenital Blindness, Intellectual Disability and Autism Spectrum Disorder

    Science.gov (United States)

    Aasen, Gro; Naerland, Terje

    2014-01-01

    This study investigates responses to verbal versus tactile requests in children with congenital blindness, intellectual disability and autism spectrum disorder (ASD). Observation was conducted on two occasions. At T1, requests were given verbally, and at T2, tactile requests were given. All pupils perceived tactile symbols to be explicit requests…

  9. Visual and spatial modulation of tactile extinction: behavioural and electrophysiological evidence

    Directory of Open Access Journals (Sweden)

    Chiara Francesca Sambo

    2012-07-01

    Full Text Available Crossing the hands over the midline reduces left tactile extinction to double simultaneous stimulation in right-brain-damaged patients, suggesting that spatial-attentional biases towards the ipsilesional (right side of space contribute to the patients’ contralesional (left deficit. We investigated (1 whether the position of the left hand, and its vision, affected processing speed of tactile stimuli, and (2 the electrophysiological underpinnings of the effect of hand position. (1 Four right-brain-damaged patients with spatial neglect and contralesional left tactile extinction or somatosensory deficits, and eight neurologically unimpaired participants, performed a speeded detection task on single taps delivered on their left index finger. In patients, placing the left hand in the right (heteronymous hemi-space resulted in faster reaction times (RTs to tactile stimuli, compared to placing that hand in the left (homonymous hemi-space, particularly when the hand was visible. By contrast, in controls placing the left hand in the heteronymous hemi-space increased RTs. (2 Somatosensory event-related potentials were recorded from one patient and two controls in response to the stimulation of the left hand, placed in the two spatial positions. In the patient, the somatosensory P70, N140, and N250 components were enhanced when the left hand was placed in the heteronymous hemi-space, whereas in controls these components were not modulated by hand position. The novel findings are that in patients placing the left hand in the right, ipsilesional hemi-space yields a temporal advantage in processing tactile stimuli, and this effect may rely on a modulation of stimulus processing taking place as early as in the primary somatosensory cortex, as indexed by evoked potentials. Furthermore, vision enhances tactile processing specifically when the left hand is placed in the hemi-space towards which the patients’ attentional biases are pathologically directed

  10. 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

  11. 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.

  12. 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.

  13. 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. PMID:22317480

  14. DF's visual brain in action: the role of tactile cues.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Byrne, Caitlin M; Goodale, Melvyn A

    2014-03-01

    Patient DF, an extensively-tested woman with visual form agnosia from ventral-stream damage, is able to scale her grip aperture to match a goal object's geometry when reaching out to pick it up, despite being unable to explicitly distinguish amongst objects on the basis of their different geometries. Using evidence from a range of sources, including functional MRI, we have proposed that she does this through a functionally intact visuomotor system housed within the dorsal stream of the posterior parietal lobe. More recently, however, Schenk (2012a). The Journal of Neuroscience, 32(6), 2013-2017; Schenk (2012b). Trends in Cognitive Sciences, 16(5), 258-259. has argued that DF performs well in visually guided grasping, not through spared and functioning visuomotor networks in the dorsal stream, but because haptic feedback about the locations of the edges of the target is available to calibrate her grasps in such tasks, whereas it is not available in standard visual perceptual tasks. We have tested this 'calibration hypothesis' directly, by presenting DF with a grasping task in which the visible width of a target varied from trial to trial while its actual width remained the same. According to the calibration hypothesis, because haptic feedback was completely uninformative, DF should be unable to calibrate her grip aperture in this task. Contrary to this prediction, we found that DF continued to scale her grip aperture to the visual width of the targets and did so well within the range of healthy controls. We also found that DF's inability to distinguish shapes perceptually is not improved by providing haptic feedback. These findings strengthen the notion that DF's spared visuomotor abilities are driven largely by visual feedforward processing of the geometric properties of the target. Crucially, these findings also indicate that simple tactile contact with an object is needed for the visuomotor dorsal stream to be engaged, and accordingly enables DF to execute

  15. Visual and tactile interfaces for bi-directional human robot communication

    Science.gov (United States)

    Barber, Daniel; Lackey, Stephanie; Reinerman-Jones, Lauren; Hudson, Irwin

    2013-05-01

    Seamless integration of unmanned and systems and Soldiers in the operational environment requires robust communication capabilities. Multi-Modal Communication (MMC) facilitates achieving this goal due to redundancy and levels of communication superior to single mode interaction using auditory, visual, and tactile modalities. Visual signaling using arm and hand gestures is a natural method of communication between people. Visual signals standardized within the U.S. Army Field Manual and in use by Soldiers provide a foundation for developing gestures for human to robot communication. Emerging technologies using Inertial Measurement Units (IMU) enable classification of arm and hand gestures for communication with a robot without the requirement of line-of-sight needed by computer vision techniques. These devices improve the robustness of interpreting gestures in noisy environments and are capable of classifying signals relevant to operational tasks. Closing the communication loop between Soldiers and robots necessitates them having the ability to return equivalent messages. Existing visual signals from robots to humans typically require highly anthropomorphic features not present on military vehicles. Tactile displays tap into an unused modality for robot to human communication. Typically used for hands-free navigation and cueing, existing tactile display technologies are used to deliver equivalent visual signals from the U.S. Army Field Manual. This paper describes ongoing research to collaboratively develop tactile communication methods with Soldiers, measure classification accuracy of visual signal interfaces, and provides an integration example including two robotic platforms.

  16. Tactile Sensitivity and Braille Reading in People with Early Blindness and Late Blindness

    Science.gov (United States)

    Oshima, Kensuke; Arai, Tetsuya; Ichihara, Shigeru; Nakano, Yasushi

    2014-01-01

    Introduction: The inability to read quickly can be a disadvantage throughout life. This study focused on the associations of braille reading fluency and individual factors, such as the age at onset of blindness and number of years reading braille, and the tactile sensitivity of people with early and late blindness. The relationship between reading…

  17. Tactile, visual, and bimodal P300s : Could bimodal P300s boost BCI performance?

    NARCIS (Netherlands)

    Brouwer, A.M.; Erp, J.B.F. van; Aloise, F.; Cincotti, F.

    2010-01-01

    The P300 is a positive peak in EEG occurring after presentation of a target stimulus. For brain-computer interfaces (BCIs), eliciting P300s by tactile stimuli would have specific advantages; the display can be hidden under clothes and keeps the user’s gaze free. In addition, robust classification is

  18. A tactile cockpit instrument supports the control of self-motion during spatial disorientation

    NARCIS (Netherlands)

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

    2006-01-01

    Objective: We investigated the effectiveness of a tactile torso display as a countermeasure to spatial disorientation (SD) and compared inside-out and outside-in codings. Background: SD is a serious threat to military as well as civilian pilots and aircraft. Considerable effort has been put into SD

  19. 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

    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...

  20. Aesthetic appreciation of tactile unity-in-variety in product designs

    NARCIS (Netherlands)

    Post, R.A.G.; Blijlevens, J.; Hekkert, P.P.M.

    2014-01-01

    The principle of unity-in-variety has recently been shown to affect visual aesthetic appreciation of product designs. We investigated whether this principle can also account for tactile aesthetic appreciation of products. Design students rated nine car keys on unity, variety and aesthetic appreciati

  1. The Universe at the Fingertips of the Visually Impaired: Building a tactile planetarium

    Science.gov (United States)

    Carvalho, C. L.; de-Aquino, H. A.

    2015-06-01

    In this work we describe a tactile planetarium made with the goal of teaching astronomy to visually impaired people, but which is accessible to all. The planetarium consists of two hemispheres representing both the northern and southern hemispheres, with around 72 constellations and more than 500 stars with different apparent magnitudes.

  2. When visual transients impair tactile change detection: a novel case of crossmodal change blindness?

    Science.gov (United States)

    Gallace, Alberto; Auvray, Malika; Tan, Hong Z; Spence, Charles

    2006-05-01

    The inability of people to detect changes between consecutively presented visual displays, when separated by a blank screen or distractor, is known as "change blindness". This phenomenon has recently been reported to occur within the auditory and tactile modalities as well. To date, however, only distractors presented within the same sensory modality as the change have been demonstrated to produce change blindness. In the present experiment, we studied whether tactile change blindness might also be elicited by the presentation of a visual mask. Participants made same versus different judgments regarding two successively presented displays composed of two to three vibrotactile stimuli. While change detection performance was near-perfect when the two displays were presented one directly after the other, participants failed to detect many of the changes between the tactile displays when they were separated by an empty temporal interval. Critically, performance deteriorated still further when the presentation of a local (i.e., a mudsplash) or global visual transient coincided with the onset of the second tactile pattern. Analysis of the results using signal detection theory revealed that this crossmodal effect reflected a genuine perceptual impairment. PMID:16480821

  3. Tactile hairs on the postcranial body in Florida manatees: a Mammalian lateral line?

    Science.gov (United States)

    Reep, R L; Marshall, C D; Stoll, M L

    2002-01-01

    Previous reports have suggested that the sparsely distributed hairs found on the entire postcranial body of sirenians are all sinus type tactile hairs. This would represent a unique arrangement because no other mammal has been reported to possess tactile hairs except on restricted regions of the body, primarily the face. In order to investigate this issue further, hair counts were made systematically in three Florida manatees (Trichechus manatus latirostris), and hair follicle microanatomy was studied in 110 specimens gathered from 9 animals. We found that the postcranial body possesses approximately 1500 hairs per side, and hair density decreases from dorsal to ventral. External hair length ranged from 2-9 mm, and most hairs were separated from their nearest neighbor by 20-40 mm, resulting in an independent domain of movement for each hair. All hairs exhibited the anatomical characteristics of follicle-sinus complexes typical of tactile hairs, including a dense connective tissue capsule containing an elongated circumferential blood sinus and innervation by 20-50 axons which ascend the mesenchymal sheath. We conclude that this represents a unique distributed underwater tactile system capable of conveying detailed and significant external information concerning approaching animals, water currents and possibly the presence of large stationary features of the environment. Such a system would be analogous to the lateral line in fish, and would be particularly useful in the turbid habitat frequented by Florida manatees. PMID:12119533

  4. 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…

  5. Accuracy and Techniques in the Preparation of Mathematics Worksheets for Tactile Learners

    Science.gov (United States)

    Rosenblum, L. Penny; Herzberg, Tina

    2011-01-01

    Data were gathered from 166 participants regarding their qualifications for and training in preparing mathematics materials for tactile learners. The participants shared information about the courses and workshops they had attended, the books and resources they used, the amount of time they spent preparing mathematics materials, and information…

  6. 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…

  7. A flexible tactile-feedback touch screen using transparent ferroelectric polymer film vibrators

    International Nuclear Information System (INIS)

    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)

  8. 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…

  9. 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. PMID:26913626

  10. 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

  11. Attention to sound improves auditory reliability in audio-tactile spatial optimal integration

    Directory of Open Access Journals (Sweden)

    Tiziana eVercillo

    2015-05-01

    Full Text Available The role of attention on multisensory processing is still poorly understood. In particular, it is unclear whether directing attention toward a sensory cue dynamically reweights cue reliability during integration of multiple sensory signals. In this study, we investigated the impact of attention in combining audio-tactile signals in an optimal fashion. We used the Maximum Likelihood Estimation (MLE model to predict audio-tactile spatial localization on the body surface. We developed a new audio-tactile device composed by several small units, each one consisting of a speaker and a tactile vibrator independently controllable by external software. We tested subjects in an attentional and a non-attentional condition. In the attention experiment participants performed a dual task paradigm: they were required to evaluate the duration of a sound while performing an audio-tactile spatial task. Three unisensory or multisensory stimuli (conflictual or not conflictual sounds and vibrations arranged along the horizontal axis were presented sequentially. In the primary task subjects had to evaluate the position of the second stimulus (the probe with respect to the others (in a space bisection task. In the secondary task they had to report occasionally changes in duration of the second auditory stimulus. In the non-attentional task participants had only to perform the primary task (space bisection. Our results showed enhanced auditory precision (and auditory weights in the auditory attentional condition with respect to the control non-attentional condition. Interestingly in both conditions the multisensory results are well predicted by the MLE model. The results of this study support the idea that modality-specific attention modulates multisensory integration.

  12. Transfer of tactile perceptual learning to untrained neighboring fingers reflects natural use relationships.

    Science.gov (United States)

    Dempsey-Jones, Harriet; Harrar, Vanessa; Oliver, Jonathan; Johansen-Berg, Heidi; Spence, Charles; Makin, Tamar R

    2016-03-01

    Tactile learning transfers from trained to untrained fingers in a pattern that reflects overlap between the representations of fingers in the somatosensory system (e.g., neurons with multifinger receptive fields). While physical proximity on the body is known to determine the topography of somatosensory representations, tactile coactivation is also an established organizing principle of somatosensory topography. In this study we investigated whether tactile coactivation, induced by habitual inter-finger cooperative use (use pattern), shapes inter-finger overlap. To this end, we used psychophysics to compare the transfer of tactile learning from the middle finger to its adjacent fingers. This allowed us to compare transfer to two fingers that are both physically and cortically adjacent to the middle finger but have differing use patterns. Specifically, the middle finger is used more frequently with the ring than with the index finger. We predicted this should lead to greater representational overlap between the former than the latter pair. Furthermore, this difference in overlap should be reflected in differential learning transfer from the middle to index vs. ring fingers. Subsequently, we predicted temporary learning-related changes in the middle finger's representation (e.g., cortical magnification) would cause transient interference in perceptual thresholds of the ring, but not the index, finger. Supporting this, longitudinal analysis revealed a divergence where learning transfer was fast to the index finger but relatively delayed to the ring finger. Our results support the theory that tactile coactivation patterns between digits affect their topographic relationships. Our findings emphasize how action shapes perception and somatosensory organization. PMID:26631145

  13. Practice makes perfect: the neural substrates of tactile discrimination by Mah-Jong experts include the primary visual cortex

    OpenAIRE

    Honda Manabu; Okada Tomohisa; Saito Daisuke N; Yonekura Yoshiharu; Sadato Norihiro

    2006-01-01

    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 ...

  14. Moving & feeling: the modulation of tactile perception during goal-directed movements: Evidence from reaching, grasping, catching, & throwing

    OpenAIRE

    Juravle, Georgiana; Spence, Charles

    2012-01-01

    This thesis focuses on tactile perception and aims at a comprehensive analysis of its characteristics over the time-course of various goal-directed movements. Tactile perception is assessed by means of discrimination and detection paradigms, as well as event-related potentials (ERPs). The main question investigated throughout the thesis is: ‘What changes in tactile perception, if any, take place over the time course of a goal-directed movement?’ In Chapter 2, the mechanisms related to such id...

  15. 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.

  16. 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.

  17. 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. PMID:26635663

  18. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans

    OpenAIRE

    Burkhard Pleger; Claudia Wilimzig; Volkmar Nicolas; Tobias Kalisch; Patrick Ragert; Martin Tegenthoff; Dinse, Hubert R.

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural ...

  19. Detection of the position, direction and speed of sliding contact with a multi-layer compliant tactile sensor fabricated using direct-print technology

    International Nuclear Information System (INIS)

    A multi-layer resistance based compliant tactile sensor was fabricated using direct-print (DP) and soft molding processes. The sensor consists of two layers of embedded stretchable sensing elements sandwiched by three layers of a polyurethane rubber material. The sensing elements were created by the DP process using a photopolymer filled with multi-wall carbon nanotubes, which exhibit the property of piezoresistivity. The printed sensing elements were fully cured using ultraviolet light. The sensing elements within each layer of the sensor structure change in electrical resistance when external forces are applied. By processing the measured sensor signals, the fabricated sensor was able to detect the position of contact forces with a 3 mm spatial resolution, as well as their two-dimensional translation directions and speeds. Based on the results, it is concluded that the fabricated sensors are promising in robotic applications and the developed process and material can be a reliable and robust way to build highly stretchable tactile sensors. (paper)

  20. 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.

  1. Voluntary movement affects simultaneous perception of auditory and tactile stimuli presented to a non-moving body part.

    Science.gov (United States)

    Hao, Qiao; Ora, Hiroki; Ogawa, Ken-Ichiro; Ogata, Taiki; Miyake, Yoshihiro

    2016-01-01

    The simultaneous perception of multimodal sensory information has a crucial role for effective reactions to the external environment. Voluntary movements are known to occasionally affect simultaneous perception of auditory and tactile stimuli presented to the moving body part. However, little is known about spatial limits on the effect of voluntary movements on simultaneous perception, especially when tactile stimuli are presented to a non-moving body part. We examined the effect of voluntary movement on the simultaneous perception of auditory and tactile stimuli presented to the non-moving body part. We considered the possible mechanism using a temporal order judgement task under three experimental conditions: voluntary movement, where participants voluntarily moved their right index finger and judged the temporal order of auditory and tactile stimuli presented to their non-moving left index finger; passive movement; and no movement. During voluntary movement, the auditory stimulus needed to be presented before the tactile stimulus so that they were perceived as occurring simultaneously. This subjective simultaneity differed significantly from the passive movement and no movement conditions. This finding indicates that the effect of voluntary movement on simultaneous perception of auditory and tactile stimuli extends to the non-moving body part. PMID:27622584

  2. A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing

    Science.gov (United States)

    Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W.F.; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B.-H.; Bao, Zhenan

    2015-01-01

    Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots. PMID:26300307

  3. 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.

  4. A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing

    Science.gov (United States)

    Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W. F.; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B.-H.; Bao, Zhenan

    2015-08-01

    Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots.

  5. Attenuation of self-generated tactile sensations is predictive, not postdictive

    OpenAIRE

    Bays, Paul M; J Randall Flanagan; Wolpert, Daniel M.

    2006-01-01

    When one finger touches the other, the resulting tactile sensation is perceived as weaker than the same stimulus externally imposed. This attenuation of sensation could result from a predictive process that subtracts the expected sensory consequences of the action, or from a postdictive process that alters the perception of sensations that are judged after the event to be self-generated. In this study we observe attenuation even when the fingers unexpectedly fail to make contact, supporting a...

  6. Marrow-Derived Cells Regulate the Development of Early Diabetic Retinopathy and Tactile Allodynia in Mice

    OpenAIRE

    Li, Guangyuan; Veenstra, Alexander A.; Talahalli, Ramaprasad R.; Wang, Xiaoqi; Gubitosi-Klug, Rose A.; Sheibani, Nader; Timothy S. Kern

    2012-01-01

    The hypothesis that marrow-derived cells, and specifically proinflammatory proteins in those cells, play a critical role in the development of diabetes-induced retinopathy and tactile allodynia was investigated. Abnormalities characteristic of the early stages of retinopathy and allodynia were measured in chimeric mice lacking inducible nitric oxide synthase (iNOS) or poly(ADP-ribosyl) polymerase (PARP1) in only their marrow-derived cells. Diabetes-induced capillary degeneration, proinflammat...

  7. NEURAL CHANGES WITH TACTILE LEARNING REFLECT DECISION-LEVEL REWEIGHTING OF PERCEPTUAL READOUT

    OpenAIRE

    Sathian, K.; Deshpande, Gopikrishna; Stilla, Randall

    2013-01-01

    Despite considerable work, the neural basis of perceptual learning remains uncertain. For visual learning, although some studies suggested that changes in early sensory representations are responsible, other studies point to decision-level reweighting of perceptual readout. These competing possibilities have not been examined in other sensory systems, investigating which could help resolve the issue. Here we report a study of human tactile microspatial learning in which participants achieved ...

  8. Pain sensitivity and tactile spatial acuity are altered in healthy musicians as in chronic pain patients.

    Directory of Open Access Journals (Sweden)

    Anna M. eZamorano

    2015-01-01

    Full Text Available Extensive training of repetitive and highly skilled movements, as it occurs in professional classical musicians, may lead to changes in tactile sensitivity and corresponding cortical reorganization of somatosensory cortices. It is also known that professional musicians frequently experience musculoskeletal pain and pain-related symptoms during their careers. The present study aimed at understanding the complex interaction between chronic pain and music training with respect to somatosensory processing. For this purpose, tactile thresholds (mechanical detection, grating orientation, two-point discrimination and subjective ratings to thermal and pressure pain stimuli were assessed in 17 professional musicians with chronic pain, 30 pain-free musicians, 20 non-musicians with chronic pain, and 18 pain-free non-musicians. We found that pain-free musicians displayed greater touch sensitivity (i.e. lower mechanical detection thresholds, lower tactile spatial acuity (i.e., higher grating orientation thresholds and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. Moreover, we also found that musicians and non-musicians with chronic pain presented lower tactile spatial acuity and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. The significant increment of pain sensitivity together with decreased spatial discrimination in pain-free musicians and the similarity of results found in chronic pain patients, suggests that the extensive training of repetitive and highly skilled movements in classical musicians could be considered as a risk factor for developing chronic pain, probably due to use-dependent plastic changes elicited in somatosensory pathways.

  9. Demonstrating the application of dielectric polymer actuators for tactile feedback in a mobile consumer device.

    OpenAIRE

    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 (DEA) promise to combine the flexibilityof a touch-screen with the intuitive use of classical buttons, but require high driving voltages. Providing the driving voltages in a mobile device, where siz...

  10. The simultaneous perception of auditory–tactile stimuli in voluntary movement

    OpenAIRE

    Hao, Qiao; Ogata, Taiki; Ogawa, Ken-ichiro; Kwon, Jinhwan; Miyake, Yoshihiro

    2015-01-01

    The simultaneous perception of multimodal information in the environment during voluntary movement is very important for effective reactions to the environment. Previous studies have found that voluntary movement affects the simultaneous perception of auditory and tactile stimuli. However, the results of these experiments are not completely consistent, and the differences may be attributable to methodological differences in the previous studies. In this study, we investigated the effect of vo...

  11. Can tactile stimuli be subitised? An unresolved controversy within the literature on numerosity judgments.

    Science.gov (United States)

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2008-01-01

    There is a growing interest in the question whether the phenomenon of subitising (fast and accurate detection of fewer than 4-5 stimuli presented simultaneously), widely thought to affect numerosity judgments in vision, can also affect the processing of tactile stimuli. In a recent study, in which multiple tactile stimuli were simultaneously presented across the body surface, Gallace et al (2006 Perception 35 247-266) concluded that tactile stimuli cannot be subitised. By contrast, Riggs et al (2006 Psychological Science 17 271 275), who presented tactile stimuli to participants' fingertips, came to precisely the opposite conclusion, arguing instead that subitising does occur in touch. Here, we re-analyse the data from both studies using more powerful statistical procedures. We show that Riggs et al's error data do not offer strong support for the subitising account and, what is more, Gallace et al's data are not entirely compatible with a linear model account of numerosity judgments in humans either. We then report an experiment in which we compare numerosity judgments for stimuli presented on the fingertips with those for stimuli presented on the rest of the body surface. The results show no major differences between the fingers and the rest of the body, and an absence of subitising in either condition. On the basis of these observations, we discuss whether the purported existence of subitisation in touch reflects a genuine cognitive phenomenon, or whether, instead, it may reflect a bias in the interpretation of the particular psychometric functions that happen to have been chosen by researchers to fit their data. PMID:18605150

  12. Dyspraxia in a patient with corticobasal degeneration: the role of visual and tactile inputs to action

    OpenAIRE

    Graham, NL; Zeman, A; Young, AW; Patterson, K.; Hodges, JR

    1999-01-01

    OBJECTIVES—To investigate the roles of visual and tactile information in a dyspraxic patient with corticobasal degeneration (CBD) who showed dramatic facilitation in miming the use of a tool or object when he was given a tool to manipulate; and to study the nature of the praxic and neuropsychological deficits in CBD.
METHODS—The subject had clinically diagnosed CBD, and exhibited alien limb behaviour and striking ideomotor dyspraxia. General neuropsychological evaluation ...

  13. The magnetic touch illusion: A perceptual correlate of visuo-tactile integration in peripersonal space.

    Science.gov (United States)

    Guterstam, Arvid; Zeberg, Hugo; Özçiftci, Vedat Menderes; Ehrsson, H Henrik

    2016-10-01

    To accurately localize our limbs and guide movements toward external objects, the brain must represent the body and its surrounding (peripersonal) visual space. Specific multisensory neurons encode peripersonal space in the monkey brain, and neurobehavioral studies have suggested the existence of a similar representation in humans. However, because peripersonal space lacks a distinct perceptual correlate, its involvement in spatial and bodily perception remains unclear. Here, we show that applying brushstrokes in mid-air at some distance above a rubber hand-without touching it-in synchrony with brushstrokes applied to a participant's hidden real hand results in the illusory sensation of a "magnetic force" between the brush and the rubber hand, which strongly correlates with the perception of the rubber hand as one's own. In eight experiments, we characterized this "magnetic touch illusion" by using quantitative subjective reports, motion tracking, and behavioral data consisting of pointing errors toward the rubber hand in an intermanual pointing task. We found that the illusion depends on visuo-tactile synchrony and exhibits similarities with the visuo-tactile receptive field properties of peripersonal space neurons, featuring a non-linear decay at 40cm that is independent of gaze direction and follows changes in the rubber hand position. Moreover, the "magnetic force" does not penetrate physical barriers, thus further linking this phenomenon to body-specific visuo-tactile integration processes. These findings provide strong support for the notion that multisensory integration within peripersonal space underlies bodily self-attribution. Furthermore, we propose that the magnetic touch illusion constitutes a perceptual correlate of visuo-tactile integration in peripersonal space. PMID:27348406

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

    OpenAIRE

    Camilla Groth; Maarit Mäkelä; Pirita Seitamaa-Hakkarainen

    2013-01-01

    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 ...

  15. Behavioral response to antennal tactile stimulation in the field cricket Gryllus bimaculatus

    OpenAIRE

    Okada, Jiro; Akamine, Seiryo

    2012-01-01

    We examined behavioral responses of the field cricket Gryllus bimaculatus to tactile stimuli to the antennae. Three stimulants of similar shape and size but different textures were used: a tibia from the hunting spider Heteropoda venatoria (potential predator), a tibia from the orb-web spider Argiope bruennichi (less likely predator), and a glass rod. Each stimulus session comprised a first gentle contact and a second strong contact. The evoked behavioral responses were classified into four c...

  16. Comparison between audio and tactile systems for delivering simple navigational information to visually impaired pedestrians

    OpenAIRE

    Gustafson-Pearce, O; Billett, EH; Cecelja, F

    2007-01-01

    Many of the current GPS (Global Positioning Systems) navigation aids use an audio method to deliver navigation information to the user. For the visually impaired person this method can be problematic. The visually impaired pedestrian relies heavily on information contained within the ambient sound environment; for location and orientation information, navigation information, and importantly, safety information. In this paper we present the design of an innovative tactile interface and verific...

  17. Posterior reversible encephalopathy syndrome with tactile hallucinations secondary to dialysis disequilibrium syndrome

    Directory of Open Access Journals (Sweden)

    Abdulsalam Soomro

    2014-01-01

    Full Text Available We report what we believe is the first case of posterior reversible encephalopathy syndrome (PRES secondary to dialysis disequilibrium syndrome (DDS in patients in whom all other possible causes of PRES were excluded and in whom a transient episode of tactile hallucination also occurred. We believe that this case of DDS was particularly severe, leading to PRES because of the late institution of dialysis therapy and the concomitant severe degree of metabolic acidosis on presentation.

  18. Application of tactile/kinesthetic stimulation in preterm infants: a systematic review

    Directory of Open Access Journals (Sweden)

    Vanessa C. Pepino

    2015-06-01

    Full Text Available OBJECTIVE: To verify the methods used by the clinical trials that assessed the effect of tactile/kinesthetic stimulation on weight gain in preterm infants and highlight the similarities and differences among such studies. SOURCES: This review collected studies from two databases, PEDro and PubMed, in July of 2014, in addition to bibliographies. Two researchers assessed the relevant titles independently, and then chose which studies to read in full and include in this review by consensus. Clinical trials that studied tactile stimulation or massage therapy whether or not associated with kinesthetic stimulation of preterm infants; that assessed weight gain after the intervention; that had a control group and were composed in English, Portuguese, or Spanish were included. SUMMARY OF THE FINDINGS: A total of 520 titles were found and 108 were selected for manuscript reading. Repeated studies were excluded, resulting in 40 different studies. Of these, 31 met all the inclusion criteria. There were many differences in the application of tactile/kinesthetic stimulation techniques among studies, which hindered the accurate reproduction of the procedure. Also, many studies did not describe the adverse events that occurred during stimulation, the course of action taken when such events occurred, and their effect on the outcome. CONCLUSIONS: These studies made a relevant contribution towards indicating tactile/kinesthetic stimulation as a promising tool. Nevertheless, there was no standard for application among them. Future studies should raise the level of methodological rigor and describe the adverse events. This may permit other researchers to be more aware of expected outcomes, and a standard technique could be established.

  19. Neuroplasticity associated with tactile language communication in a deaf-blind subject

    OpenAIRE

    Souzana Obretenova; Halko, Mark A.; Plow, Ela B.; Alvaro Pascual-Leone; Merabet, Lotfi B.

    2010-01-01

    A longstanding debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI), we compared the neural networks associated with the tactile reading of words presented in Braille, Print o...

  20. Neuroplasticity Associated with Tactile Language Communication in a Deaf-Blind Subject

    OpenAIRE

    Obretenova, Souzana; Halko, Mark A.; Plow, Ela B.; Pascual-Leone, Alvaro; Merabet, Lotfi B.

    2010-01-01

    A long-standing debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI), we compared the neural networks associated with the tactile reading of words presented in Braille, Print ...

  1. Attentional bias in normal subjects performing visual and tactile radial line bisections.

    Science.gov (United States)

    Chewning, J; Adair, J C; Heilman, E B; Heilman, K M

    1998-11-01

    Misbisection of lines is thought to represent an attentional bias. When radial lines (intersection of the midsagittal and transverse planes) are presented below eye level, normal subjects are biased toward far peripersonal space in the visual modality and to near peripersonal space in the tactile modality. These errors may be related to a body centered, a retinotopic, or an object centered attentional bias. The purpose of this study was to contrast the body centered and retinotopic-objective centered hypotheses by having 12 normal subjects perform visual and tactile bisections of radial lines that are above and below eye level. The top of the page, which may be defined by retinotopic or object centered coordinates, contains the portion of the line that is most distant from our bodies when the page is below eye level. However, above eye level, the top of a radial line would be the portion of the page that is most proximal to our bodies. We observed that when stimuli are presented below eye level, normal subjects have a visual bias toward far peripersonal space or the top of the page or both, and have a tactile bias in the opposite direction. In the above eye position we found no overall bias in either modality. Because above eye level the body centered bias should have remained the same but the retinotopic or object centered bias should have reversed, our results suggest that the body and object centered or retinotopic biases, which are oriented in opposite directions, nullified each other. PMID:9842756

  2. Audio-tactile integration in congenitally and late deaf cochlear implant users.

    Directory of Open Access Journals (Sweden)

    Elena Nava

    Full Text Available Several studies conducted in mammals and humans have shown that multisensory processing may be impaired following congenital sensory loss and in particular if no experience is achieved within specific early developmental time windows known as sensitive periods. In this study we investigated whether basic multisensory abilities are impaired in hearing-restored individuals with deafness acquired at different stages of development. To this aim, we tested congenitally and late deaf cochlear implant (CI recipients, age-matched with two groups of hearing controls, on an audio-tactile redundancy paradigm, in which reaction times to unimodal and crossmodal redundant signals were measured. Our results showed that both congenitally and late deaf CI recipients were able to integrate audio-tactile stimuli, suggesting that congenital and acquired deafness does not prevent the development and recovery of basic multisensory processing. However, we found that congenitally deaf CI recipients had a lower multisensory gain compared to their matched controls, which may be explained by their faster responses to tactile stimuli. We discuss this finding in the context of reorganisation of the sensory systems following sensory loss and the possibility that these changes cannot be "rewired" through auditory reafferentation.

  3. Tactile Distinction of an Artery and a Tumor in a Soft Tissue by Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ali A.  Mehrizi

    2008-01-01

    Full Text Available Tactile detection of a tumor and an artery in a tissue and distinction of a healthy artery from a stenotic artery, using finite element method, are presented. Four 2D models of tissue have been created: tissue itself, tissue including a tumor (TIT, tissue including a healthy artery (TIHA, and tissue including a stenotic artery (TISA. After solving four models with similar boundary conditions and loadings, the 2D tactile mappings and stress graphs for upper nodes of models, which have key importance for transferring tactile data, were explored. Then, by comparing these results, if the stress values of nodes were constant and equal, tissue is unlikely to have any tumor or artery embedded. Otherwise, if the stress graph included a peak, the tissue had a tumor or an artery. Additionally, it was observed that the stress graph of tissue including an artery is time-dependent in comparison with the tissue including a tumor. Further, it was concluded that a stenotic artery had larger stress peak than a healthy artery.

  4. Non-invasive mechanical properties estimation of embedded objects using tactile imaging sensor

    Science.gov (United States)

    Saleheen, Firdous; Oleksyuk, Vira; Sahu, Amrita; Won, Chang-Hee

    2013-05-01

    Non-invasive mechanical property estimation of an embedded object (tumor) can be used in medicine for characterization between malignant and benign lesions. We developed a tactile imaging sensor which is capable of detecting mechanical properties of inclusions. Studies show that stiffness of tumor is a key physiological discerning parameter for malignancy. As our sensor compresses the tumor from the surface, the sensing probe deforms, and the light scatters. This forms the tactile image. Using the features of the image, we can estimate the mechanical properties such as size, depth, and elasticity of the embedded object. To test the performance of the method, a phantom study was performed. Silicone rubber balls were used as embedded objects inside the tissue mimicking substrate made of Polydimethylsiloxane. The average relative errors for size, depth, and elasticity were found to be 67.5%, 48.2%, and 69.1%, respectively. To test the feasibility of the sensor in estimating the elasticity of tumor, a pilot clinical study was performed on twenty breast cancer patients. The estimated elasticity was correlated with the biopsy results. Preliminary results show that the sensitivity of 67% and the specificity of 91.7% for elasticity. Results from the clinical study suggest that the tactile imaging sensor may be used as a tumor malignancy characterization tool.

  5. Sound Interferes with the Early Tactile Manual Abilities of Preterm Infants.

    Science.gov (United States)

    Lejeune, Fleur; Parra, Johanna; Berne-Audéoud, Frédérique; Marcus, Leïla; Barisnikov, Koviljka; Gentaz, Edouard; Debillon, Thierry

    2016-01-01

    Premature birth is a sudden change of the sensory environment of a newborn, while their senses are still in development, especially in the stressful and noisy environment of the NICU. The study aimed to evaluate the effect of noise on the early tactile manual abilities of preterm infants (between 29 and 35 weeks PCA). Infants were randomly assigned to one of the two conditions: Silence and Noise. For each condition, two phases were introduced: a habituation phase (repeated presentation of the same object, prism or cylinder), followed by a test phase (presentation of the familiar or a novel object). In the Silence condition, they received the tactile habituation and test phases: In the Noise condition, they went through the same phases, while an alarm sounded. Sixty-three preterm infants were included. They displayed a strong and effective ability to memorize tactile manual information and to detect the difference between two shape features, but this ability seems to be impaired by the concomitant exposure to an alarm sound. This study is the first to highlight the effect of a negative stimulus on sensory functioning in premature infants. It reinforces the importance of developing environmental measures to lower the sound level in NICUs. PMID:26987399

  6. Real-Time Knee Adduction Moment Feedback for Gait Retraining Through Visual and Tactile Displays

    KAUST Repository

    Wheeler, Jason W.

    2011-01-01

    The external knee adduction moment (KAM) measured during gait is an indicator of tibiofemoral joint osteoarthritis progression and various strategies have been proposed to lower it. Gait retraining has been shown to be an effective, noninvasive approach for lowering the KAM. We present a new gait retraining approach in which the KAM is fed back to subjects in real-time during ambulation. A study was conducted in which 16 healthy subjects learned to alter gait patterns to lower the KAM through visual or tactile (vibration) feedback. Participants converged on a comfortable gait in just a few minutes by using the feedback to iterate on various kinematic modifications. All subjects adopted altered gait patterns with lower KAM compared with normal ambulation (average reduction of 20.7%). Tactile and visual feedbacks were equally effective for real-time training, although subjects using tactile feedback took longer to converge on an acceptable gait. This study shows that real-time feedback of the KAM can greatly increase the effectiveness and efficiency of subject-specific gait retraining compared with conventional methods. © 2011 American Society of Mechanical Engineers.

  7. La lettura di un TIB (Tactile Illustrated Book) come contesto per l'espressione di domande da parte dei bambini con deficit visivo. Una ricerca esplorativa

    OpenAIRE

    Polato, Enrica

    2013-01-01

    The present doctoral work finds its motivation in a deficiency and an intent. The deficiency (and, in certain countries, even absence) regards the availability of Tactile Illustrated Books (TIB); tactile picture books, created for children of pre-school age who are blind or with visual impairment. The Baby Infant Tactile Illustrated Books (BITIB) Group attempts to address such shortage by developing prototypes of some such books. One of these book prototypes was entrusted to the Univers...

  8. Maternal perception of fever in children by tactile technique how valid it is

    International Nuclear Information System (INIS)

    To determine the validity of tactile technique as a tool for fever assessment in children by mothers. Study Design: A cohort study. Place and Duration of Study: The study was conducted at the department of Paediatrics, Combined Military Hospital, Bahawalpur, Pakistan, from September 2007 to September 2009. Patients and Methods: Convenient sampling technique was employed. Three hundred and ninety three children between the ages of 6 months and 5 years, brought to hospital by mothers with history of prolonged fever (7 days or more) perceived by tactile technique. Children were not supposed to be necessarily febrile at the time of enrollment. A six hourly temperature recording was done. Moreover, whenever mothers felt that their child is febrile by using tactile method of their choice, axillary thermometry was done irrespective of the number of recordings. Standard mercury thermometry by axillary technique (without adding a degree to measured value) was chosen. Reading of more than 99.50 Fahrenheit (37.50 centigrade) was labeled as fever. Cases that remained fever free for five days were labeled afebrile and discharged. Mothers were advised to watch for fever for one week at home and to report back immediately if they felt that their child has fever, confirmed by a single tactile measurement. Those who reported back were readmitted and subjected to the same method of monitoring and recording as was applied on first admission. Data was analyzed using SPSS version 17. Descriptive statistics were applied to calculate the frequencies, means and standard deviations. Results: Among the 392 children 58.4% were males and 41.4% were females. The mean age was 24.4 +-14.39 months. Majority had a history of fever of 5 to 24 days (70.2%). In only 184 (46.93%) patients fever was confirmed. In 208 (53.08%) patients no fever was recorded and were discharged. Twenty one patients reported back with fever. However, fever was confirmed in only 11 patients. In summary, a total of 195 (49

  9. The facilitatory influence of anterior cingulate cortex on ON-OFF response of tactile neuron in thalamic ventrobasal nucleus

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropostero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on receptive fields of ON-OFF neurons showed that the excitation of the ACC could change an ON-response on the verge of a receptive field into an ON-OFF response. The above results suggest that the ACC modulation sharpens the response of a VB neuron to a moving stimulus within its receptive field, indicating that the limbic system can modulate tactile ascending sensory information.

  10. Effective learning and retention of braille letter tactile discrimination skills in children with developmental dyslexia.

    Science.gov (United States)

    Hayek, Maisam; Dorfberger, Shoshi; Karni, Avi

    2016-01-01

    Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural ('how to') knowledge as long-term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without reading difficulties (DD, typical readers), to improve their tactile discrimination with practice and tested the children's ability to retain the gains. Forty 10-11-year-olds practiced the tactile discrimination of four braille letters, presented as pairs, while blindfolded. In a trial, participants were asked to report whether the target stimuli were identical or different from each other. The structured training session consisted of six blocks of 16 trials each. Performance was re-tested at 24 hours and two weeks post-training. Both groups improved in speed and in accuracy. In session 1, children with DD started as significantly less accurate and were slower than the typical readers but showed rapid learning and successfully closed the gap. Only two children with DD failed to benefit from training and were not included in subsequent data analyses. At 24 hours post-training both groups showed effective retention of the gains in speed and accuracy. Importantly, children with DD were able to retain the gains in speed and accuracy, over a two-week interval as effectively as typical readers. Thus, children with DD were as effective in the acquisition and retention of tactile discrimination of braille letters as typical readers of the same age. The results do not support the notion of a general procedural learning disability in DD. PMID:25754250

  11. Voluntary action and tactile sensory feedback in the intentional binding effect.

    Science.gov (United States)

    Zhao, Ke; Hu, Li; Qu, Fangbing; Cui, Qian; Piao, Qiuhong; Xu, Hui; Li, Yanyan; Wang, Liang; Fu, Xiaolan

    2016-08-01

    The intentional binding effect refers to a subjective compression over a temporal interval between the start point initialized by a voluntary action and the endpoint signaled by an external sensory (visual or audio) feedback. The present study aimed to explore the influence of tactile sensory feedback on this binding effect by comparing voluntary key-press actions with voluntary key-release actions. In experiment 1, each participant was instructed to report the perceived interval (in ms) between an action and the subsequent visual sensory feedback. In this task, either the action (key-press or key-release) was voluntarily performed by the participant or a kinematically identical movement was passively applied to the left index finger of the participant. In experiment 2, we explored whether the difference in the perception of time was affected by the direction of action. In experiment 3, we developed an apparatus in which two parallel laser beams were generated by a laser emission unit and detected by a laser receiver unit; this allowed the movement of the left index finger to be detected without it touching a keyboard (i.e., without any tactile sensory feedback). Convergent results from all of the experiments showed that the temporal binding effect was only observed when the action was both voluntary and involved physical contact with the key, suggesting that the combination of intention and tactile sensory feedback, as a form of top-down processing, likely distracted attention from temporal events and caused the different binding effects. PMID:27038203

  12. Tactile Gap Detection Deteriorates during Bimanual Symmetrical Movements under Mirror Visual Feedback.

    Directory of Open Access Journals (Sweden)

    Janet H Bultitude

    Full Text Available It has been suggested that incongruence between signals for motor intention and sensory input can cause pain and other sensory abnormalities. This claim is supported by reports that moving in an environment of induced sensorimotor conflict leads to elevated pain and sensory symptoms in those with certain painful conditions. Similar procedures can lead to reports of anomalous sensations in healthy volunteers too. In the present study, we used mirror visual feedback to investigate the effects of sensorimotor incongruence on responses to stimuli that arise from sources external to the body, in particular, touch. Incongruence between the sensory and motor signals for the right arm was manipulated by having the participants make symmetrical or asymmetrical movements while watching a reflection of their left arm in a parasagittal mirror, or the left hand surface of a similarly positioned opaque board. In contrast to our prediction, sensitivity to the presence of gaps in tactile stimulation of the right forearm was not reduced when participants made asymmetrical movements during mirror visual feedback, as compared to when they made symmetrical or asymmetrical movements with no visual feedback. Instead, sensitivity was reduced when participants made symmetrical movements during mirror visual feedback relative to the other three conditions. We suggest that small discrepancies between sensory and motor information, as they occur during mirror visual feedback with symmetrical movements, can impair tactile processing. In contrast, asymmetrical movements with mirror visual feedback may not impact tactile processing because the larger discrepancies between sensory and motor information may prevent the integration of these sources of information. These results contrast with previous reports of anomalous sensations during exposure to both low and high sensorimotor conflict, but are nevertheless in agreement with a forward model interpretation of perceptual

  13. Asymmetrical learning between a tactile and visual serial RT task

    NARCIS (Netherlands)

    Abrahamse, Elger L.; Lubbe, van der Rob H.J.; Verwey, Willem B.

    2007-01-01

    According to many researchers, implicit learning in the serial reaction-time task is predominantly motor based and therefore should be independent of stimulus modality. Previous research on the task, however, has focused almost completely on the visual domain. Here we investigated sequence learning

  14. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    Science.gov (United States)

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  15. Attenuation of self-generated tactile sensations is predictive, not postdictive.

    Directory of Open Access Journals (Sweden)

    Paul M Bays

    2006-02-01

    Full Text Available When one finger touches the other, the resulting tactile sensation is perceived as weaker than the same stimulus externally imposed. This attenuation of sensation could result from a predictive process that subtracts the expected sensory consequences of the action, or from a postdictive process that alters the perception of sensations that are judged after the event to be self-generated. In this study we observe attenuation even when the fingers unexpectedly fail to make contact, supporting a predictive process. This predictive attenuation of self-generated sensation may have evolved to enhance the perception of sensations with an external cause.

  16. Design and technical construction of a tactile display for sensory feedback in a hand prosthesis system

    Directory of Open Access Journals (Sweden)

    Antfolk Christian

    2010-09-01

    Full Text Available Abstract Background The users of today's commercial prosthetic hands are not given any conscious sensory feedback. To overcome this deficiency in prosthetic hands we have recently proposed a sensory feedback system utilising a "tactile display" on the remaining amputation residual limb acting as man-machine interface. Our system uses the recorded pressure in a hand prosthesis and feeds back this pressure onto the forearm skin. Here we describe the design and technical solution of the sensory feedback system aimed at hand prostheses for trans-radial/humeral amputees. Critical parameters for the sensory feedback system were investigated. Methods A sensory feedback system consisting of five actuators, control electronics and a test application running on a computer has been designed and built. Firstly, we investigate which force levels were applied to the forearm skin of the user while operating the sensory feedback system. Secondly, we study if the proposed system could be used together with a myoelectric control system. The displacement of the skin caused by the sensory feedback system would generate artefacts in the recorded myoelectric signals. Accordingly, EMG recordings were performed and an analysis of the these are included. The sensory feedback system was also preliminarily evaluated in a laboratory setting on two healthy non-amputated test subjects with a computer generating the stimuli, with regards to spatial resolution and force discrimination. Results We showed that the sensory feedback system generated approximately proportional force to the angle of control. The system can be used together with a myoelectric system as the artefacts, generated by the actuators, were easily removed using a simple filter. Furthermore, the application of the system on two test subjects showed that they were able to discriminate tactile sensation with regards to spatial resolution and level of force. Conclusions The results of these initial experiments

  17. Tactile Gloves for Autonomous Grasping With the NASA/DARPA Robonaut

    Science.gov (United States)

    Martin, T. B.; Ambrose, R. O.; Diftler, M. A.; Platt, R., Jr.; Butzer, M. J.

    2004-01-01

    Tactile data from rugged gloves are providing the foundation for developing autonomous grasping skills for the NASA/DARPA Robonaut, a dexterous humanoid robot. These custom gloves compliment the human like dexterity available in the Robonaut hands. Multiple versions of the gloves are discussed, showing a progression in using advanced materials and construction techniques to enhance sensitivity and overall sensor coverage. The force data provided by the gloves can be used to improve dexterous, tool and power grasping primitives. Experiments with the latest gloves focus on the use of tools, specifically a power drill used to approximate an astronaut's torque tool.

  18. 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...... Measuring Machine (OCMM) allowing fast measurements suitable for in-line quality control were employed as validation instruments. The experimental work carried out and the analysis of the results provide valuable conclusions about the advantages and drawbacks of using CT metrology in comparison with CMM and...

  19. Attenuation of Self-Generated Tactile Sensations is Predictive, not Postdictive.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available When one finger touches the other, the resulting tactile sensation is perceived as weaker than the same stimulus externally imposed. This attenuation of sensation could result from a predictive process that subtracts the expected sensory consequences of the action, or from a postdictive process that alters the perception of sensations that are judged after the event to be self-generated. In this study we observe attenuation even when the fingers unexpectedly fail to make contact, supporting a predictive process. This predictive attenuation of self-generated sensation may have evolved to enhance the perception of sensations with an external cause.

  20. Field trials of a tactile acoustic monitor for the profoundly deaf.

    Science.gov (United States)

    Summers, I R; Peake, M A; Martin, M C

    1981-08-01

    Profoundly deaf subjects were given information about sound level in their environment by means of a body-worn unit coupled to a small vibrator worn on the finger. Results of trials on 19 adults are discussed. The Tactile Acoustic Monitor was found to be useful for identifying domestic sounds by means of their distinctive timing patterns. No significant overall improvement in subject's control of voice level was observed, although some subjects found that having a voice level monitor gave them greater confidence to join conversations. Various design improvements were suggested by the trials. Modifications which have been incorporated into an improved unit are described. PMID:7296098

  1. Mechanics of localized slippage in tactile sensing and application to soft sensing systems

    CERN Document Server

    Ho, Anh-Van

    2014-01-01

    Localized slippage occurs during any relative sliding of soft contacts, ranging from human fingertips to robotic fingertips. Although this phenomenon is dominant for a very short time prior to gross slippage, localized slippage is a crucial factor for any to-be-developed soft sensing system to respond to slippage before it occurs. The content of this book addresses all aspects of localized slippage, including modeling and simulating it, as well as applying it to the construction of novel sensors with slip tactile perception.

  2. Behavioral impact of unisensory and multisensory audio-tactile events: pros and cons for interlimb coordination in juggling.

    Directory of Open Access Journals (Sweden)

    Gregory Zelic

    Full Text Available Recent behavioral neuroscience research revealed that elementary reactive behavior can be improved in the case of cross-modal sensory interactions thanks to underlying multisensory integration mechanisms. Can this benefit be generalized to an ongoing coordination of movements under severe physical constraints? We choose a juggling task to examine this question. A central issue well-known in juggling lies in establishing and maintaining a specific temporal coordination among balls, hands, eyes and posture. Here, we tested whether providing additional timing information about the balls and hands motions by using external sound and tactile periodic stimulations, the later presented at the wrists, improved the behavior of jugglers. One specific combination of auditory and tactile metronome led to a decrease of the spatiotemporal variability of the juggler's performance: a simple sound associated to left and right tactile cues presented antiphase to each other, which corresponded to the temporal pattern of hands movement in the juggling task. A contrario, no improvements were obtained in the case of other auditory and tactile combinations. We even found a degraded performance when tactile events were presented alone. The nervous system thus appears able to integrate in efficient way environmental information brought by different sensory modalities, but only if the information specified matches specific features of the coordination pattern. We discuss the possible implications of these results for the understanding of the neuronal integration process implied in audio-tactile interaction in the context of complex voluntary movement, and considering the well-known gating effect of movement on vibrotactile perception.

  3. Tactile massage and hypnosis as a health promotion for nurses in emergency care-a qualitative study

    Directory of Open Access Journals (Sweden)

    Nordby-Hörnell Elisabeth

    2011-10-01

    Full Text Available 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 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.

  4. Une ontologie pour la conception d'une plateforme collaborative exploitant une table multi- tactile et multi-modale

    OpenAIRE

    Joiron, Céline; Fürst, Frédéric; Kassel, Gilles; Jones, Alistair; Barthès, Jean-Paul,; Moulin, Claude; Lenne, Dominique

    2013-01-01

    L'objectif du projet TATIN-PIC (TAble Tactile Interactive et Plateforme Intelligente de Conception), est de développer une plateforme exploitant une table interactive multi-tactile et multi-modale dédiée à la conception préliminaire. À cette fin, une ontologie – OntoTATIN-PIC – est construite pour représenter les connaissances liées aux dispositifs et à l'activité de conception. Dans cet article, nous présentons, d'une part, l'originalité de cette ontologie : OntoTATIN-PIC étend l'ontologie f...

  5. Tactile information processing in the trigeminal complex of the rat

    Science.gov (United States)

    Pavlov, Alexey N.; Tupitsyn, Anatoly N.; Makarov, Valery A.; Panetsos, Fivos; Moreno, Angel; Garcia-Gonzalez, Victor; Sanchez-Jimenez, Abel

    2007-02-01

    We study mechanisms of information processing in the principalis (Pr5), oralis (Sp5o) and interpolaris (Sp5i) nuclei of the trigeminal sensory complex of the rat under whisker stimulation by short air puffs. After the standard electrophysiological description of the neural spiking activity we apply a novel wavelet based method quantifying the structural stability of firing patterns evoked by a periodic whisker stimulation. We show that the response stability depends on the puff duration delivered to the vibrissae and differs among the analyzed nuclei. Pr5 and Sp5i exhibit the maximal stability to an intermediate stimulus duration, whereas Sp5o shows "preference" for short stimuli.

  6. Parylene coated carbon nanotube actuators for tactile stimulation

    Science.gov (United States)

    Bubak, Grzegorz; Ansaldo, Alberto; Gendron, David; Brayda, Luca; Ceseracciu, Luca; Ricci, Davide

    2015-04-01

    Ionic liquid/carbon nanotube based actuators have been constantly improved in recent years owing to their suitability for applications related to human-machine interaction and robotics thanks to their light-weight and low voltage operation. However, while great attention has been paid to the development of better electrodes and electrolytes, no adequate efforts were made to develop actuators to be used in direct contact with the human skin. Herein, we present our approach, based on the use of parylene-C coating. Indeed, owning to its physicochemical properties such as high dielectric strength, resistance to solvents, biological and chemical inactivity/inertness, parylene fulfils the requirements for use in biocompatible actuator fabrication. In this paper, we study the influence of the parylene coating on the actuator performance. To do so, we analyzed its mechanical and electrochemical properties. We looked into the role of parylene as a protection layer that can prevent alteration of the actuator performance likely caused by external conditions. In order to complete our study, we designed a haptic device and investigated the generated force, displacement and energy usage.

  7. Sensory supplementation system based on electrotactile tongue biofeedback of head position for balance control

    CERN Document Server

    Vuillerme, Nicolas; Chenu, Olivier; Demongeot, Jacques; Payan, Yohan; Danilov, Yuri

    2008-01-01

    The present study aimed at investigating the effects of an artificial head position-based tongue-placed electrotactile biofeedback on postural control during quiet standing under different somatosensory conditions from the support surface. Eight young healthy adults were asked to stand as immobile as possible with their eyes closed on two Firm and Foam support surface conditions executed in two conditions of No-biofeedback and Biofeedback. In the Foam condition, a 6-cm thick foam support surface was placed under the subjects' feet to alter the quality and/or quantity of somatosensory information at the plantar sole and the ankle. The underlying principle of the biofeedback consisted of providing supplementary information about the head orientation with respect to gravitational vertical through electrical stimulation of the tongue. Centre of foot pressure (CoP) displacements were recorded using a force platform. Larger CoP displacements were observed in the Foam than Firm conditions in the two conditions of No...

  8. The brain’s response to pleasant touch: an EEG investigation of tactile caressing

    Directory of Open Access Journals (Sweden)

    Harsimrat eSingh

    2014-11-01

    Full Text Available Somatosensation as a proximal sense can have a strong impact on our attitude towards physical objects and other human beings. However, relatively little is known about how hedonic valence of touch is processed at the cortical level. Here we investigated the electrophysiological correlates of affective tactile sensation during caressing of the right forearm with pleasant and unpleasant textile fabrics. We show dissociation between more physically driven differential brain responses to the different fabrics in early somatosensory cortex – the well-known mu-suppression (10-20 Hz - and a beta-band response (25-30 Hz in presumably higher-order somatosensory areas in the right-hemisphere that correlated well with the subjective valence of tactile caressing. Importantly, when using single trial classification techniques, beta-power significantly distinguished between pleasant and unpleasant stimulation on a single trial basis with high accuracy. Our results therefore suggest a dissociation of the sensory and affective aspects of touch in the somatosensory system and may provide features that may be used for single trial decoding of affective mental states from simple electroencephalographic measurements.

  9. A Control Strategy with Tactile Perception Feedback for EMG Prosthetic Hand

    Directory of Open Access Journals (Sweden)

    Changcheng Wu

    2015-01-01

    Full Text Available To improve the control effectiveness and make the prosthetic hand not only controllable but also perceivable, an EMG prosthetic hand control strategy was proposed in this paper. The control strategy consists of EMG self-learning motion recognition, backstepping controller with stiffness fuzzy observation, and force tactile representation. EMG self-learning motion recognition is used to reduce the influence on EMG signals caused by the uncertainty of the contacting position of the EMG sensors. Backstepping controller with stiffness fuzzy observation is used to realize the position control and grasp force control. Velocity proportional control in free space and grasp force tracking control in restricted space can be realized by the same controller. The force tactile representation helps the user perceive the states of the prosthetic hand. Several experiments were implemented to verify the effect of the proposed control strategy. The results indicate that the proposed strategy has effectiveness. During the experiments, the comments of the participants show that the proposed strategy is a better choice for amputees because of the improved controllability and perceptibility.

  10. Tactile Cueing as a Gravitational Substitute for Spatial Navigation During Parabolic Flight

    Science.gov (United States)

    Montgomery, K. L.; Beaton, K. H.; Barba, J. M.; Cackler, J. M.; Son, J. H.; Horsfield, S. P.; Wood, S. J.

    2010-01-01

    INTRODUCTION: Spatial navigation requires an accurate awareness of orientation in your environment. The purpose of this experiment was to examine how spatial awareness was impaired with changing gravitational cues during parabolic flight, and the extent to which vibrotactile feedback of orientation could be used to help improve performance. METHODS: Six subjects were restrained in a chair tilted relative to the plane floor, and placed at random positions during the start of the microgravity phase. Subjects reported their orientation using verbal reports, and used a hand-held controller to point to a desired target location presented using a virtual reality video mask. This task was repeated with and without constant tactile cueing of "down" direction using a belt of 8 tactors placed around the mid-torso. Control measures were obtained during ground testing using both upright and tilted conditions. RESULTS: Perceptual estimates of orientation and pointing accuracy were impaired during microgravity or during rotation about an upright axis in 1g. The amount of error was proportional to the amount of chair displacement. Perceptual errors were reduced during movement about a tilted axis on earth. CONCLUSIONS: Reduced perceptual errors during tilts in 1g indicate the importance of otolith and somatosensory cues for maintaining spatial awareness. Tactile cueing may improve navigation in operational environments or clinical populations, providing a non-visual non-auditory feedback of orientation or desired direction heading.

  11. A Case of Right Alien Hand Syndrome Coexisting with Right-Sided Tactile Extinction.

    Science.gov (United States)

    Schaefer, Michael; Denke, Claudia; Apostolova, Ivayla; Heinze, Hans-Jochen; Galazky, Imke

    2016-01-01

    The alien hand syndrome (AHS) is a fascinating movement disorder. Patients with AHS experience one of their limbs as alien, which acts autonomously and performs meaningful movements without being guided by the intention of the patient. Here, we report a case of a 74-years old lady diagnosed with an atypical Parkinson syndrome by possible corticobasal degeneration. The patient stated that she could not control her right hand and that she felt like this hand had her own life. We tested the patient for ownership illusions of the hands and general tactile processing. Results revealed that when blindfolded, the patient recognized touch to her alien hand only if it was presented separated from touch to the other hand (bilateral asynchronous touch). Delivering touch synchronously to both the alien and the healthy hand resulted in failure of recognizing touch to the alien hand (bilateral synchronous touch). Thus, AHS here co-existed with right-sided tactile extinction and is one of only very few cases in which the alien hand was felt on the right side. We discuss the results in the light of recent research on AHS. PMID:27014036

  12. Haptic exploration of fingertip-sized geometric features using a multimodal tactile sensor

    Science.gov (United States)

    Ponce Wong, Ruben D.; Hellman, Randall B.; Santos, Veronica J.

    2014-06-01

    Haptic perception remains a grand challenge for artificial hands. Dexterous manipulators could be enhanced by "haptic intelligence" that enables identification of objects and their features via touch alone. Haptic perception of local shape would be useful when vision is obstructed or when proprioceptive feedback is inadequate, as observed in this study. In this work, a robot hand outfitted with a deformable, bladder-type, multimodal tactile sensor was used to replay four human-inspired haptic "exploratory procedures" on fingertip-sized geometric features. The geometric features varied by type (bump, pit), curvature (planar, conical, spherical), and footprint dimension (1.25 - 20 mm). Tactile signals generated by active fingertip motions were used to extract key parameters for use as inputs to supervised learning models. A support vector classifier estimated order of curvature while support vector regression models estimated footprint dimension once curvature had been estimated. A distal-proximal stroke (along the long axis of the finger) enabled estimation of order of curvature with an accuracy of 97%. Best-performing, curvature-specific, support vector regression models yielded R2 values of at least 0.95. While a radial-ulnar stroke (along the short axis of the finger) was most helpful for estimating feature type and size for planar features, a rolling motion was most helpful for conical and spherical features. The ability to haptically perceive local shape could be used to advance robot autonomy and provide haptic feedback to human teleoperators of devices ranging from bomb defusal robots to neuroprostheses.

  13. Development of Grousers with a Tactile Sensor for Wheels of Lunar Exploration Rovers to Measure Sinkage

    Directory of Open Access Journals (Sweden)

    Kojiro Iizuka

    2014-03-01

    Full Text Available This paper presents a grouser developed for the wheels of lunar exploration rovers to measure sinkage. The wheels, which are intended to traverse loose soil such as lunar regolith, contain grousers that transfer thrust to the wheels and thus to the body of the rover. The interaction between the wheel (with grousers and the loose soil can be described using a kinematic model. When traversing loose soil, the wheel sinks into the soil, which necessitates knowledge of the entrance angle needed in order to avoid this problem. If the entrance angle is known, the sinkage can be measured in real time before adverse conditions occur. Because of the importance and usefulness of detecting the entrance angle of the wheel, we herein propose a grouser with an embedded tactile sensor. A strain gauge on the surface of the grousers serves as the tactile sensor. In order to confirm the precision of the proposed grouser, we have performed tests on a rigid surface and loose soil surfaces.

  14. The imagination of touch: surrealist tactility in the films of Jan Švankmajer

    Directory of Open Access Journals (Sweden)

    Kristoffer Noheden

    2013-09-01

    Full Text Available This article is a theoretical examination of tactility in the Czech surrealist filmmaker Jan Švankmajer's film Down to the Cellar (1983. Švankmajer's deployment of tactile images in a surrealist context shows the need for a discussion of the imagination's role in the embodied film experience. Departing from Laura Marks's The Skin of the Film, this article seeks to explore the surrealist embodied imagination through surrealist poetics of analogy, as defined by André Breton, and the link between these and Walter Benjamin's writings on mimesis. Finally, the film is viewed from the perspective of Gaston Bachelard's ideas of “the imagination of matter,” where matter is seen as a highly potent stimulant for the imagination. Bachelard's notion of the imagination's multisensory properties further lends credence to Švankmajer's aims to liberate the imagination of the spectator through images that invoke touch. Kristoffer Noheden is a PhD candidate in cinema studies at the Department of Media Studies, Stockholm University. In his dissertation, he examines surrealism's attempts to create a new, re-enchanting myth with a focus on its expressions in surrealist cinema. He is the co-editor, with Daniel Brodén, of the anthology I gränslandet: Nya perspektiv på film och modernism (Gidlunds, 2013. He is also the translator into Swedish of books by William S. Burroughs, Leonora Carrington, Max Ernst, and others, and co-runs the surrealist-oriented publishing house Sphinx.

  15. Behavioral response to antennal tactile stimulation in the field cricket Gryllus bimaculatus.

    Science.gov (United States)

    Okada, Jiro; Akamine, Seiryo

    2012-07-01

    We examined behavioral responses of the field cricket Gryllus bimaculatus to tactile stimuli to the antennae. Three stimulants of similar shape and size but different textures were used: a tibia from the hunting spider Heteropoda venatoria (potential predator), a tibia from the orb-web spider Argiope bruennichi (less likely predator), and a glass rod. Each stimulus session comprised a first gentle contact and a second strong contact. The evoked behavioral responses were classified into four categories: aversion, aggression, antennal search, and no response. Regardless of the stimulants, the crickets exhibited antennal search and aversion most frequently in response to the first and second stimuli, respectively. The frequency of aversion was significantly higher to the tibia of H. venatoria than to other stimulants. The most striking observation was that aggressive responses were exclusive to the H. venatoria tibia. To specify the hair type that induced aggression, we manipulated two types of common hairs (bristle and fine) on the tibia of the predatory spider. When bristle hairs were removed from the H. venatoria tibia, aggression was significantly reduced. These results suggest that antennae can discriminate the tactile texture of external objects and elicit adaptive behavioral responses. PMID:22534774

  16. Peripheral tactile sensory perception of older adults improved using subsensory electrical noise stimulation.

    Science.gov (United States)

    Breen, Paul P; Serrador, Jorge M; O'Tuathail, Claire; Quinlan, Leo R; McIntosh, Caroline; ÓLaighin, Gearóid

    2016-08-01

    Loss of tactile sensory function is common with aging and can lead to numbness and difficulty with balance and gait. In previous work we found that subsensory electrical noise stimulation (SENS) applied to the tibial nerve improved tactile perception in the soles of the feet of healthy adults. In this work we aimed to determine if SENS remained effective in an older adult population with significant levels of sensory loss. Older adult subjects (N=8, female = 4, aged 65-80) had SENS applied via surface electrodes placed proximally to the medial and lateral malleoli. Vibration perception thresholds (VPTs) were assessed in six conditions, two control conditions (no SENS) and four SENS conditions (zero mean ±15µA, 30µA, 45µA and 60µA SD). VPT was assessed at three sites on the plantar aspect of the foot. Vibration perception was significantly improved in the presence of ±30µA SENS and by 16.2±2.4% (mean ± s.e.m.) when optimised for each subject. The improvement in perception was similar across all VPT test sites. PMID:27317362

  17. Tactile Robotic Topographical Mapping Without Force or Contact Sensors

    Science.gov (United States)

    Burke, Kevin; Melko, Joseph; Krajewski, Joel; Cady, Ian

    2008-01-01

    A method of topographical mapping of a local solid surface within the range of motion of a robot arm is based on detection of contact between the surface and the end effector (the fixture or tool at the tip of the robot arm). The method was conceived to enable mapping of local terrain by an exploratory robot on a remote planet, without need to incorporate delicate contact switches, force sensors, a vision system, or other additional, costly hardware. The method could also be used on Earth for determining the size and shape of an unknown surface in the vicinity of a robot, perhaps in an unanticipated situation in which other means of mapping (e.g., stereoscopic imaging or laser scanning with triangulation) are not available. The method uses control software modified to utilize the inherent capability of the robotic control system to measure the joint positions, the rates of change of the joint positions, and the electrical current demanded by the robotic arm joint actuators. The system utilizes these coordinate data and the known robot-arm kinematics to compute the position and velocity of the end effector, move the end effector along a specified trajectory, place the end effector at a specified location, and measure the electrical currents in the joint actuators. Since the joint actuator current is approximately proportional to the actuator forces and torques, a sudden rise in joint current, combined with a slowing of the joint, is a possible indication of actuator stall and surface contact. Hence, even though the robotic arm is not equipped with contact sensors, it is possible to sense contact (albeit with reduced sensitivity) as the end effector becomes stalled against a surface that one seeks to measure.

  18. Real-time vision, tactile cues, and visual form agnosia in pantomimed grasping: removing haptic feedback induces a switch from natural to pantomime-like grasps

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2015-05-01

    Full Text Available Investigators study the kinematics of grasping movements (prehension under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. When patient DF, who suffers from visual form agnosia, performs natural grasps, her in-flight hand aperture is scaled to the widths of targets ('grip scaling' that she cannot discriminate amongst. In contrast, when DF's pantomime grasps are based on a memory of a previewed object, her grip scaling is very poor. Her failure on this task has been interpreted as additional support for the dissociation between the use of object vision for action and object vision for perception. Curiously, however, when DF directs her pantomimed grasps towards a displaced imagined copy of a visible object where her fingers make contact with the surface of the table, her grip scaling does not appear to be particularly poor. In the first of two experiments, we revisit this previous work and show that her grip scaling in this real-time pantomime grasping task does not differ from controls, suggesting that terminal tactile feedback from a proxy of the target can maintain DF's grip scaling. In a second experiment with healthy participants, we tested a recent variant of a grasping task in which no tactile feedback is available (i.e. no haptic feedback by comparing the kinematics of target-directed grasps with and without haptic feedback to those of real-time pantomime grasps without haptic feedback. Compared to natural grasps, removing haptic feedback increased RT, slowed the velocity of the reach, reduced grip aperture, sharpened the slopes relating grip aperture to target width, and reduced the final grip aperture. All of these effects were also observed in the pantomime grasping task. Taken together, these results provide compelling support for the view that removing haptic feedback induces a switch from real-time visual control to one that depends more on visual perception and cognitive supervision.

  19. Integrating measuring uncertainty of tactile and optical coordinate measuring machines in the process capability assessment of micro injection moulding

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Gasparin, Stefania

    Process capability of micro injection moulding was investigated in this paper by calculating the Cp and Cpk statistics. Uncertainty of both optical and tactile measuring systems employed in the quality control of micro injection moulded products was assessed and compared with the specified tolera...

  20. The Use of a Tactile-Vision Sensory Substitution System as an Augmentative Tool for Individuals with Visual Impairments

    Science.gov (United States)

    Williams, Michael D.; Ray, Christopher T.; Griffith, Jennifer; De l'Aune, William

    2011-01-01

    The promise of novel technological strategies and solutions to assist persons with visual impairments (that is, those who are blind or have low vision) is frequently discussed and held to be widely beneficial in countless applications and daily activities. One such approach involving a tactile-vision sensory substitution modality as a mechanism to…

  1. Using Commercially Available Techniques to Make Organic Chemistry Representations Tactile and More Accessible to Students with Blindness or Low Vision

    Science.gov (United States)

    Supalo, Cary A.; Kennedy, Sean H.

    2014-01-01

    Organic chemistry courses can present major obstacles to access for students with blindness or low vision (BLV). In recent years, efforts have been made to represent organic chemistry concepts in tactile forms for blind students. These methodologies are described in this manuscript. Further work being done at Illinois State University is also…

  2. How Tactile and Function Information Affect Young Children's Ability to Understand the Nature of Food-Appearing, Deceptive Objects

    Science.gov (United States)

    Krause, Christina Miles

    2008-01-01

    Preschool children's (N = 64) ability to use tactile information and function cues on less-realistic and more-realistic food-appearing, deceptive objects was examined before and after training on the function of deceptive objects. They also responded to appearance and reality questions about deceptive objects. Half of the children (F-S:…

  3. The facilitatory influence of anterior cingulate cortex on ON-OFF response of tactile neuron in thalamic ventrobasal nucleus

    Institute of Scientific and Technical Information of China (English)

    曹晓华; 卢湘岳; 周绍慈

    2000-01-01

    The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropos-tero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on rec

  4. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans.

    Science.gov (United States)

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition. PMID:27302219

  5. Impact of Tactile-Cued Self-Monitoring on Independent Biology Work for Secondary Students with Attention Deficit Hyperactivity Disorder

    Science.gov (United States)

    Morrison, Catherine; McDougall, Dennis; Black, Rhonda S.; King-Sears, Margaret E.

    2014-01-01

    Results from a multiple baseline with changing conditions design across high school students with Attention Deficit Hyperactivity Disorder (ADHD) indicated that the students increased the percentage of independent work they completed in their general education biology class after learning tactile-cued self-monitoring. Students maintained high…

  6. Using Tactile Learning Aids for Students with Visual Impairments in a First-Semester Organic Chemistry Course

    Science.gov (United States)

    Poon, Thomas; Ovadia, Ronit

    2008-01-01

    This paper describes two techniques for rendering visual concepts encountered in an organic chemistry course into tactile representations for students who have low vision. The techniques--which utilize commercially available products--facilitate communication of organic chemistry between student and instructor. (Contains 1 figure, 2 tables and 1…

  7. Microsurgeons do better--tactile training might prevent the age-dependent decline of the sensibility of the hand.

    Science.gov (United States)

    Schmauss, Daniel; Megerle, Kai; Weinzierl, Andrea; Agua, Kariem; Cerny, Michael; Schmauss, Verena; Lohmeyer, Joern A; Machens, Hans-Guenther; Erne, Holger

    2015-12-01

    Recent data demonstrate that the normal sensibility of the hand seems to be age-dependent with the best values in the third decade and a consecutive deterioration afterwards. However, it is not clear if long-term tactile training might prevent this age-dependent decline. We evaluated sensibility of the hand in 125 surgeons aged between 26 and 75 years who perform microsurgical operations, thereby undergoing regular tactile training. We examined sensibility of the radial digital nerve of the index finger (N3) and the ulnar digital nerve of the small finger (N10) using static and moving two-point discrimination (2PD) tests and compared the results to 154 age-matched individuals without specific long-term tactile training. We found significantly lower static and moving 2PD values for the sixth, seventh, and eighth decade of life in the microsurgery group compared to the control group (p < 0.05). This study demonstrates that long-term tactile training might prevent the known age-dependent decline of the sensibility of the hand. PMID:26306813

  8. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans

    Science.gov (United States)

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R.

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition. PMID:27302219

  9. "It's a Sort of Echo...": Sensory Perception of the Environment as an Aid to Tactile Map Design

    Science.gov (United States)

    Gardiner, Ann; Perkins, Chris

    2005-01-01

    The results of an empirical investigation into how visually-impaired people sense their surroundings show that a range of environmental features can be identified using sound, touch and smell. The information gained is relevant to the design of tactile maps, to ensure that an area is represented in a way that is meaningful to the map users.…

  10. The Rubber Hand Illusion in Children with Autism Spectrum Disorders: Delayed Influence of Combined Tactile and Visual Input on Proprioception

    Science.gov (United States)

    Cascio, Carissa J.; Foss-Feig, Jennifer H.; Burnette, Courtney P.; Heacock, Jessica L.; Cosby, Akua A.

    2012-01-01

    In the rubber hand illusion, perceived hand ownership can be transferred to a rubber hand after synchronous visual and tactile stimulation. Perceived body ownership and self-other relation are foundational for development of self-awareness, imitation, and empathy, which are all affected in autism spectrum disorders (ASD). We examined the rubber…

  11. Within-hemifield posture changes affect tactile-visual exogenous spatial cueing without spatial precision, especially in the dark.

    Science.gov (United States)

    Kennett, Steffan; Driver, Jon

    2014-05-01

    We investigated the effects of seen and unseen within-hemifield posture changes on crossmodal visual-tactile links in covert spatial attention. In all experiments, a spatially nonpredictive tactile cue was presented to the left or the right hand, with the two hands placed symmetrically across the midline. Shortly after a tactile cue, a visual target appeared at one of two eccentricities within either of the hemifields. For half of the trial blocks, the hands were aligned with the inner visual target locations, and for the remainder, the hands were aligned with the outer target locations. In Experiments 1 and 2, the inner and outer eccentricities were 17.5º and 52.5º, respectively. In Experiment 1, the arms were completely covered, and visual up-down judgments were better when on the same side as the preceding tactile cue. Cueing effects were not significantly affected by hand or target alignment. In Experiment 2, the arms were in view, and now some target responses were affected by cue alignment: Cueing for outer targets was only significant when the hands were aligned with them. In Experiment 3, we tested whether any unseen posture changes could alter the cueing effects, by widely separating the inner and outer target eccentricities (now 10º and 86º). In this case, hand alignment did affect some of the cueing effects: Cueing for outer targets was now only significant when the hands were in the outer position. Although these results confirm that proprioception can, in some cases, influence tactile-visual links in exogenous spatial attention, they also show that spatial precision is severely limited, especially when posture is unseen. PMID:24470256

  12. Transcranial Direct Current Stimulation Over the Primary and Secondary Somatosensory Cortices Transiently Improves Tactile Spatial Discrimination in Stroke Patients

    Science.gov (United States)

    Fujimoto, Shuhei; Kon, Noriko; Otaka, Yohei; Yamaguchi, Tomofumi; Nakayama, Takeo; Kondo, Kunitsugu; Ragert, Patrick; Tanaka, Satoshi

    2016-01-01

    In healthy subjects, dual hemisphere transcranial direct current stimulation (tDCS) over the primary (S1) and secondary somatosensory cortices (S2) has been found to transiently enhance tactile performance. However, the effect of dual hemisphere tDCS on tactile performance in stroke patients with sensory deficits remains unknown. The purpose of this study was to investigate whether dual hemisphere tDCS over S1 and S2 could enhance tactile discrimination in stroke patients. We employed a double-blind, crossover, sham-controlled experimental design. Eight chronic stroke patients with sensory deficits participated in this study. We used a grating orientation task (GOT) to measure the tactile discriminative threshold of the affected and non-affected index fingers before, during, and 10 min after four tDCS conditions. For both the S1 and S2 conditions, we placed an anodal electrode over the lesioned hemisphere and a cathodal electrode over the opposite hemisphere. We applied tDCS at an intensity of 2 mA for 15 min in both S1 and S2 conditions. We included two sham conditions in which the positions of the electrodes and the current intensity were identical to that in the S1 and S2 conditions except that current was delivered for the initial 15 s only. We found that GOT thresholds for the affected index finger during and 10 min after the S1 and S2 conditions were significantly lower compared with each sham condition. GOT thresholds were not significantly different between the S1 and S2 conditions at any time point. We concluded that dual-hemisphere tDCS over S1 and S2 can transiently enhance tactile discriminative task performance in chronic stroke patients with sensory dysfunction. PMID:27064531

  13. The dynamic modeling and design improvement of a piezoelectric exciter of a touch screen device for efficient tactile feedback

    International Nuclear Information System (INIS)

    Piezoelectric exciters have been receiving greater attention recently as a vibration source for tactile feedback in devices with touch screens, such as a mobile phones, in place of DC motors due to lower energy consumption and smaller volume. Their insufficient excitation level, however, still remains a problem. In this paper, dynamic modeling and design improvement of a piezoelectric exciter are presented. The excitation performance is defined as the acceleration response at the center of a touch screen per electric power and to be maximized around 250 Hz where the index finger is most sensitive. The piezoelectric exciter consists of a z-shaped metal beam, a piezoelectric layer on the long horizontal segment and an adhesive layer between the short horizontal segment and the touch screen. Assuming that the piezoelectric exciter is attached onto a rigid ground due to its low mechanical impedance compared with that of the touch screen, the piezoelectric exciter is dynamically modeled by applying Hamilton's principle, where the adhesive layer is treated as a distributed stiffness. The touch screen is modeled approximately as a simply supported beam such that it may have the same fundamental natural frequency and bending stiffness as the screen based on measurements. The performance improvement is focused on the change of five geometric parameters of the piezoelectric exciter: length of the long horizontal segment, thickness of the piezoelectric layer, thickness of the elastic metal layer, width of the beams and tip mass. The procedure to improve the performance of the piezoelectric exciter via dynamic modeling is presented together with experimental results on a prototype. Effectiveness of the design modification and limitations in practice are further discussed as well

  14. Estimulação tátil-cinestésica: uma integração entre pele e sistema endócrino? Tactile-kinesthetic stimulation: integration between skin and endocrine system?

    Directory of Open Access Journals (Sweden)

    Monalisa C. Fogaça

    2006-09-01

    Full Text Available Apresenta-se uma revisão da literatura sobre os aspectos neuroendócrinos da pele e as conseqüências da estimulação tátil-cinestésica sobre o córtex adrenal. Os artigos foram identificados a partir das bases de dados MEDLINE e LILACS, usando as palavras-chave "córtex supra-renal", "pele", "massagem", "lactentes", "glicocorticóide" e "ritmo circadiano". O período pesquisado foi de 1990 a 2003. Foram também consultados artigos de destaque publicados antes desse período. Estudos reconhecem o hipotálamo, a hipófise e a glândula adrenal como órgãos dinâmicos durante o desenvolvimento fetal e neonatal, e que respostas de estresse estão presentes ao nascer. A maioria dos estudos revisados, utilizando a estimulação tátil-cinestésica, seja em humanos ou animais, evidencia a capacidade da pele em metabolizar, coordenar e organizar estímulos externos, procurando manter a homeostase interna e externa, demonstrando a interação entre sistema neuroendócrino e a pele. A estimulação tátil-cinestésica parece ter um efeito sobre a reatividade hormonal, porém essa questão merece uma investigação mais aprofundada.A literature review on skin neuroendocrine aspects and the consequences of the tactile- kinesthetic stimulation on the adrenal cortex are presented. The articles were identified through MEDLINE and LILACS data bases, using the keywords "suprarenal cortex", "skin", "massage", "infants", "glucocorticoid" and "circadian rhythm". Single articles published between 1990 and 2003 were considered, as well as outstanding ones prior to this period. Studies recognize that the hypothalamus, the pituitary and the adrenal gland are dynamic organs during fetal and neonatal development, and that stress responses are active at birth. Most of the studies reviewed, using tactile-kinesthetic stimulation, both in humans and animals, confirm skin's ability to metabolize, coordinate and organize external stimuli, attempting to maintain both

  15. 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

    Various non-visual inputs produce cross-modal responses in the visual cortex of early blind subjects. In order to determine the qualitative experience associated with these occipital activations, we systematically stimulated the entire occipital cortex using single pulse transcranial magnetic...... 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...... polysynaptic cortical pathway between the somatosensory cortex and the visual cortex in early blind subjects. These results also add new evidence that the activity of the occipital lobe in the blind takes its qualitative expression from the character of its new input source, therefore supporting the cortical...

  16. Effect of fingerprints orientation on skin vibrations during tactile exploration of textured surfaces

    CERN Document Server

    Prevost, Alexis; Debrégeas, Georges

    2009-01-01

    In humans, the tactile perception of fine textures is mediated by skin vibrations when scanning the surface with the fingertip. These vibrations are encoded by specific mechanoreceptors, Pacinian corpuscules (PCs), located about 2 mm below the skin surface. In a recent article, we performed experiments using a biomimetic sensor which suggest that fingerprints (epidermal ridges) may play an important role in shaping the subcutaneous stress vibrations in a way which facilitates their processing by the PC channel. Here we further test this hypothesis by directly recording the modulations of the fingerpad/substrate friction force induced by scanning an actual fingertip across a textured surface. When the fingerprints are oriented perpendicular to the scanning direction, the spectrum of these modulations shows a pronounced maximum around the frequency v/lambda, where v is the scanning velocity and lambda the fingerprints period. This simple biomechanical result confirms the relevance of our previous finding for hu...

  17. Effects of passive tactile and auditory stimuli on left visual neglect.

    Science.gov (United States)

    Hommel, M; Peres, B; Pollak, P; Memin, B; Besson, G; Gaio, J M; Perret, J

    1990-05-01

    Patients with left-sided visual neglect fail to copy the left part of drawings or the drawings on the left side of a sheet of paper. Our aim was to study the variations in copying drawings induced by passive stimulation in patients with left-sided visual neglect. No stimulation at all, tactile unilateral and bilateral, binaural auditory verbal, and nonverbal stimuli were randomly applied to 14 patients with right-hemisphere strokes. Only nonverbal stimuli decreased the neglect. As nonverbal stimuli mainly activate the right hemisphere, the decrease in neglect suggests right-hemispheric hypoactivity at rest in these patients. The absence of modification of neglect during verbal stimulation suggests a bilateral hemispheric activation and the persistence of interhemispheric imbalance. Our results showed that auditory pathways take part in the network involved with neglect. Passive nonverbal auditory stimuli may be of interest in the rehabilitation of patients with left visual neglect. PMID:2334306

  18. A Rapid Tactile-Motor Reflex Automatically Guides Reaching toward Handheld Objects.

    Science.gov (United States)

    Pruszynski, J Andrew; Johansson, Roland S; Flanagan, J Randall

    2016-03-21

    The ability to respond quickly and effectively when objects in the world suddenly change position is essential for skilled action, and previous work has documented how unexpected changes in the location of a visually presented target during reaching can elicit rapid reflexive (i.e., automatic) corrections of the hand's trajectory [1-12]. In object manipulation and tool use, the sense of touch can also provide information about changes in the location of reach targets. Consider the many tasks where we reach with one hand to part of an object grasped by the other hand: reaching to a berry while holding a branch, reaching for a cap while grasping a bottle, and reaching toward a dog's collar while holding the dog's leash. In such cases, changes in the position of the reach target, due to wind, slip, or an active agent, can be detected, in principle, through touch. Here, we show that when people reach with their right hand to a target attached to the far end of a rod contacted, at the near end, by their left hand, an unexpected change in target location caused by rod rotation rapidly evokes an effective reach correction. That is, spatial information about a change in target location provided by tactile inputs to one hand elicits a rapid correction of the other hand's trajectory. In addition to uncovering a tactile-motor reflex that can support manipulatory actions, our results demonstrate that automatic reach corrections to moving targets are not unique to visually registered changes in target location. PMID:26898466

  19. Hand tactile discrimination, social touch and frailty criteria in elderly people: A cross sectional observational study.

    Science.gov (United States)

    Vieira, Ana Isabel; Nogueira, Dália; de Azevedo Reis, Elisabeth; da Lapa Rosado, Maria; Vânia Nunes, Maria; Castro-Caldas, Alexandre

    2016-01-01

    Frailty is a common syndrome among elderly and sensory decline may exacerbate functional decline. The hand function, the manual dexterity, the performance of the daily living skills and the social interactions are determined, in a large degree, by sensory integrity. However, hand tactile sensory deterioration has been little explored in frailty. We performed a cross sectional observational study with 181 of institutionalized elders. From the initial sample we selected 50 subjects (68-99 years) who met the inclusion/exclusion criteria. Our goals were (1) to analyse the relationship between tactile discrimination (TD) of the hand, avoidance behaviours and attitudes towards social touch (BATST) and phenotype frailty criteria (unintentional weight loss, self-perception of exhaustion, decrease grip strength - GS, slow walking speed, low level of physical activity), (2) to explore whether other variables can contribute to explain the differences between pre-frail and frail elders. The results showed that increasing age is related to decline of TD of the hand (p=0.021) and to decrease in GS (p=0.025); women have significantly lower level of GS (p=0.001); TD decrease is correlated with higher avoidance BATST (p=0.000) and with lower GS (p=0.000); Lower GS corresponds to more avoidance BATST (p=0.003). Hand TD also can differentiate frail and pre-frail elderly subjects in this sample (p=0.037). Decreased TD of the hand may have implications on the functionality and on interpersonal relationships. TD of the hand also explains frailty levels in this sample. Hand TD should be used in assessment and intervention protocols in pre-frail and frail elders. PMID:27259030

  20. An analytical model for studying the structural effects and optimization of a capacitive tactile sensor array

    International Nuclear Information System (INIS)

    This paper presents an analytical model to study the structural effects of a capacitive tactile sensor array on its capacitance changes and sensitivities. The tactile sensor array has 8  ×  8 sensor units, and each unit utilizes the truncated polydimethylsiloxane (PDMS) pyramid array structure as the dielectric layer to enhance the sensing performance. To predict the capacitance changes of the sensor unit, it is simplified into a two-layered structure: upper polyethylene terephthalate (PET) film and bottom truncated PDMS pyramid array. The upper PET is modeled by a displacement field function, while each of the truncated pyramids is analyzed to obtain its stress–strain relation. Using the Ritz method, the displacement field functions are solved. The deformation of the upper electrodes and the capacitance changes of the sensor unit can then be calculated. Using the developed model, the structural effects of the truncated PDMS pyramid array and the PDMS bump on the capacitance changes and sensitivities are studied. To achieve the largest capacitance changes, the dimensions have been optimized for the sensor unit. To verify the developed model, we have fabricated the sensor array, and the average sensitivities of the sensor unit to the x-, y-, and z-axes force are 0.49, 0.50, and 0.32% mN−1, respectively, while the model predicted values are 0.54, 0.54, and 0.35% mN−1. Results demonstrate that the developed model can accurately predict the sensing performance of the sensor array and could be utilized for structural optimization. (paper)

  1. An analytical model for studying the structural effects and optimization of a capacitive tactile sensor array

    Science.gov (United States)

    Liang, Guanhao; Wang, Yancheng; Mei, Deqing; Xi, Kailun; Chen, Zichen

    2016-04-01

    This paper presents an analytical model to study the structural effects of a capacitive tactile sensor array on its capacitance changes and sensitivities. The tactile sensor array has 8  ×  8 sensor units, and each unit utilizes the truncated polydimethylsiloxane (PDMS) pyramid array structure as the dielectric layer to enhance the sensing performance. To predict the capacitance changes of the sensor unit, it is simplified into a two-layered structure: upper polyethylene terephthalate (PET) film and bottom truncated PDMS pyramid array. The upper PET is modeled by a displacement field function, while each of the truncated pyramids is analyzed to obtain its stress-strain relation. Using the Ritz method, the displacement field functions are solved. The deformation of the upper electrodes and the capacitance changes of the sensor unit can then be calculated. Using the developed model, the structural effects of the truncated PDMS pyramid array and the PDMS bump on the capacitance changes and sensitivities are studied. To achieve the largest capacitance changes, the dimensions have been optimized for the sensor unit. To verify the developed model, we have fabricated the sensor array, and the average sensitivities of the sensor unit to the x-, y-, and z-axes force are 0.49, 0.50, and 0.32% mN-1, respectively, while the model predicted values are 0.54, 0.54, and 0.35% mN-1. Results demonstrate that the developed model can accurately predict the sensing performance of the sensor array and could be utilized for structural optimization.

  2. Referral of tactile stimuli to action points in virtual reality with reaction force.

    Science.gov (United States)

    Moizumi, Shunjiro; Yamamoto, Shinya; Kitazawa, Shigeru

    2007-09-01

    When we touch something with a tool, we feel the touch at the tip of the tool rather than at the hand. Yamamoto and Kitazawa [Yamamoto, S., Kitazawa, S., 2001b. Sensation at the tips of invisible tools. Nat. Neurosci. 4, 979-980] previously showed that the judgment of the temporal order of two successive stimuli, delivered to the tips of sticks held in each hand, was dramatically altered by crossing the sticks without changing the positions of the hands. This provided evidence for the referral of tactile signals to the tip of a tool in hand. In this study, we examined importance of force feedback from the tool in the referral by manipulating the direction of force feedback in a virtual reality. The virtual tool consisted of a spherical action point that was moved with a stylus in hand. Subjects held two styli, one in each hand, put each action point on each of two buttons in the virtual reality, and were required to judge the order of successive taps, delivered to the two styli. We manipulated the direction of reaction force from each button so that it was congruent or incongruent to the visual configuration of the button. When the arms were uncrossed, judgment primarily depended on whether the action points were crossed or not in the visual space. But when the arms were crossed, judgment critically depended on the direction of force feedback. The results show that tactile signals can be referred to the action point in the virtual reality and that the force feedback becomes a critical factor when the arms are crossed. PMID:17617482

  3. Characterization of evoked tactile sensation in forearm amputees with transcutaneous electrical nerve stimulation

    Science.gov (United States)

    Chai, Guohong; Sui, Xiaohong; Li, Si; He, Longwen; Lan, Ning

    2015-12-01

    Objective. The goal of this study is to characterize the phenomenon of evoked tactile sensation (ETS) on the stump skin of forearm amputees using transcutaneous electrical nerve stimulation (TENS). Approach. We identified the projected finger map (PFM) of ETS on the stump skin in 11 forearm amputees, and compared perceptual attributes of the ETS in nine forearm amputees and eight able-bodied subjects using TENS. The profile of perceptual thresholds at the most sensitive points (MSPs) in each finger-projected area was obtained by modulating current amplitude, pulse width, and frequency of the biphasic, rectangular current stimulus. The long-term stability of the PFM and the perceptual threshold of the ETS were monitored in five forearm amputees for a period of 11 months. Main results. Five finger-specific projection areas can be independently identified on the stump skin of forearm amputees with a relatively long residual stump length. The shape of the PFM was progressively similar to that of the hand with more distal amputation. Similar sensory modalities of touch, pressure, buzz, vibration, and numb below pain sensation could be evoked both in the PFM of the stump skin of amputees and in the normal skin of able-bodied subjects. Sensory thresholds in the normal skin of able-bodied subjects were generally lower than those in the stump skin of forearm amputees, however, both were linearly modulated by current amplitude and pulse width. The variation of the MSPs in the PFM was confined to a small elliptical area with 95% confidence. The perceptual thresholds of thumb-projected areas were found to vary less than 0.99 × 10-2 mA cm-2. Significance. The stable PFM and sensory thresholds of ETS are desirable for a non-invasive neural interface that can feed back finger-specific tactile information from the prosthetic hand to forearm amputees.

  4. Communicative-Tactile Behavior in Author’s Remarks as a Constituent Part of Dialogue Interaction in German-Language Dramatic Texts

    OpenAIRE

    Aleksandr Mihaylovich Polikarpov; Artur Vladislavovich Brik

    2015-01-01

    The article considers verbs and verbal phrases as representative means of communiсative-tactile behavior in author's remarks in dramatic texts via perspective of interactional lingua-semiotics. It displays dialogue interactions in the drama as a system of verbal and nonverbal cues in human interaction. The author's remarks in dramatic texts written in the German language are proved to be a reflection of the communicative-tactile behavior of characters thus becoming a constituent part of artis...

  5. Evaluation of a magnetic resonance-compatible dentoalveolar tactile stimulus device

    Directory of Open Access Journals (Sweden)

    Bereiter David A

    2010-10-01

    Full Text Available Abstract Background Few methods exist to study central nervous system processes following dentoalveolar tactile stimulation using functional magnetic resonance imaging (fMRI, likely due to inherent technical difficulties. Our primary goal was to develop and perform feasibility testing of a novel device capable of delivering valid and reliable dentoalveolar stimuli at dental chair-side and during MRI. Details of a device designed to deliver dentoalveolar dynamic pressure stimuli are described. Device testing took place in three settings: a laboratory testing to assess range of stimulus force intensities, b dental chair-side to assess reliability, validity and discriminant ability in force-pain relationship; and c MRI to evaluate magnetic compatibility and ability to evoke brain activation in painfree subjects similar to those described in the literature. Results A novel device capable of delivering valid and reliable dentoalveolar somatosensory stimulation was developed (ICC = 0.89, 0.78-1 [95% CI]. Psychophysical data analysis showed high discriminant ability in differentiating painfree controls from cases with chronic dentoalveolar pain related to deafferenting dental procedures (sensitivity = 100%, specificity = 86.7%, area under ROC curve = 0.99. FMRI results of dentoalveolar dynamic pressure pain in painfree subjects revealed activation of brain areas typically associated with acute pain processing including thalamus, primary/secondary somatosensory, insular and prefrontal cortex. Conclusions A novel psychophysical method to deliver dynamic dentoalveolar pressure stimulation was developed and validated, allowing non-invasive MRI-based exploration of central nervous system function in response to intraoral somatosensation. Background The organization of the trigeminal system is unique as it provides somatosensory innervation to the face, masticatory and oral structures, the majority of the intracranial contents 1 and to specialized structures

  6. A grayscale pneumatic micro-valve for use in a reconfigurable tactile tablet for vision-impaired individuals

    International Nuclear Information System (INIS)

    The design, fabrication, and characterization of a strained bilayer film for use in a micro-valve for a reconfigurable tactile tablet for vision-impaired individuals is presented. The bilayer film consists of a compressive and tensile layer to cause the film to coil and retract from the gas channel when the micro-valve is in the open position. A novel support structure that improves yield and controls the direction of coiling is demonstrated. An array of 225 strained bilayer films was designed and fabricated. Each strained bilayer film was able to be actuated individually with a voltage that ranged between 60 and 70 V. The relationship between the applied voltage and the percentage open of the micro-valve is found to be linear over an extended voltage range, enabling the reconfigurable tactile tablet to produce the equivalent of a grayscale image. (paper)

  7. Impact of verbal, braille text, and tactile oral hygiene awareness instructions on oral health status of visually impaired children

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    P Brahmanna Chowdary

    2016-01-01

    Full Text Available Background: Visually impaired children face limitations in interacting with the environment, as they cannot see the facial expression of parents, teachers and cannot perceive social behavior. These children are challenged every day in learning basic life skills and maintenance of oral hygiene being one among them. Aim: To evaluate the impact of verbal, braille text, and tactile oral hygiene awareness instructions on oral health status of visually impaired children. Materials and Methods: One hundred and twenty institutionalized visually impaired children aged 6-16 years were selected and divided into three groups (40 children each. Group I: Verbal and tactile, Group II: Verbal and braille, Group III: Verbal, braille, and tactile. Instructions regarding maintenance of good oral hygiene and brushing technique were explained to all the children, and oral health status of these children using plaque index (Silness and Loe and gingival index (Loe and Silness was evaluated at 1, 3, and 6 months interval. Statistical Analysis: ANOVA test was used to analyze the intra- and inter-group comparisons and Tukey post-hoc test for multiple group comparisons. Results: Children in all the groups showed reduction in plaque and gingival scores. There was the highest percentage of reduction in plaque scores in Group III (70.6%, and the decrease in gingival scores was the highest in Group II (84%. Conclusion: Severity of dental plaque and gingivitis in visually impaired individuals can be reduced by a controlled and supervised educational program. The combination of all three, i.e., verbal, braille, and tactile mode of oral health educational aids proved to be effective.

  8. Synaptic responses evoked by tactile stimuli in Purkinje cells in mouse cerebellar cortex Crus II in vivo.

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    Chun-Ping Chu

    Full Text Available BACKGROUND: Sensory stimuli evoke responses in cerebellar Purkinje cells (PCs via the mossy fiber-granule cell pathway. However, the properties of synaptic responses evoked by tactile stimulation in cerebellar PCs are unknown. The present study investigated the synaptic responses of PCs in response to an air-puff stimulation on the ipsilateral whisker pad in urethane-anesthetized mice. METHODS AND MAIN RESULTS: Thirty-three PCs were recorded from 48 urethane-anesthetized adult (6-8-week-old HA/ICR mice by somatic or dendritic patch-clamp recording and pharmacological methods. Tactile stimulation to the ipsilateral whisker pad was delivered by an air-puff through a 12-gauge stainless steel tube connected with a pressurized injection system. Under current-clamp conditions (I = 0, the air-puff stimulation evoked strong inhibitory postsynaptic potentials (IPSPs in the somata of PCs. Application of SR95531, a specific GABA(A receptor antagonist, blocked IPSPs and revealed stimulation-evoked simple spike firing. Under voltage-clamp conditions, tactile stimulation evoked a sequence of transient inward currents followed by strong outward currents in the somata and dendrites in PCs. Application of SR95531 blocked outward currents and revealed excitatory postsynaptic currents (EPSCs in somata and a temporal summation of parallel fiber EPSCs in PC dendrites. We also demonstrated that PCs respond to both the onset and offset of the air-puff stimulation. CONCLUSIONS: These findings indicated that tactile stimulation induced asynchronous parallel fiber excitatory inputs onto the dendrites of PCs, and failed to evoke strong EPSCs and spike firing in PCs, but induced the rapid activation of strong GABA(A receptor-mediated inhibitory postsynaptic currents in the somata and dendrites of PCs in the cerebellar cortex Crus II in urethane-anesthetized mice.

  9. Learning Touch Preferences with a Tactile Robot Using Dopamine Modulated STDP in a Model of Insular Cortex

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    Ting-Shuo eChou

    2015-07-01

    Full Text Available Neurorobots enable researchers to study how behaviors are produced by neural mechanisms in an uncertain, noisy, real-world environment. To investigate how the somatosensory system processes noisy, real-world touch inputs, we introduce a neurorobot called CARL-SJR, which has a full-body tactile sensory area. The design of CARL-SJR is such that it encourages people to communicate with it through gentle touch. CARL-SJR provides feedback to users by displaying bright colors on its surface. In the present study, we show that CARL-SJR is capable of learning associations between conditioned stimuli (CS; a color pattern on its surface and unconditioned stimuli (US; a preferred touch pattern by applying a spiking neural network (SNN with neurobiologically inspired plasticity. Specifically, we modeled the primary somatosensory cortex, prefrontal cortex, striatum, and the insular cortex, which is important for hedonic touch, to process noisy data generated directly from CARL-SJR’s tactile sensory area. To facilitate learning, we applied dopamine-modulated Spike Timing Dependent Plasticity (STDP to our simulated prefrontal cortex, striatum and insular cortex. To cope with noisy, varying inputs, the SNN was tuned to produce traveling waves of activity that carried spatiotemporal information. Despite the noisy tactile sensors, spike trains, and variations in subject hand swipes, the learning was quite robust. Further, the plasticity (i.e., STDP in primary somatosensory cortex and insular cortex in the incremental pathway of dopaminergic reward system allowed us to control CARL-SJR’s preference for touch direction without heavily pre-processed inputs. The emerged behaviors we found in this model match animal’s behaviors wherein they prefer touch in particular areas and directions. Thus, the results in this paper could serve as an explanation on the underlying neural mechanisms for developing tactile preferences and hedonic touch.

  10. The rubber hand illusion in children with autism spectrum disorders: delayed influence of combined tactile and visual input on proprioception

    OpenAIRE

    Cascio, Carissa J.; Foss-Feig, Jennifer H; Burnette, Courtney P.; Heacock, Jessica L.; Cosby, Akua A.

    2012-01-01

    In the rubber hand illusion, perceived hand ownership can be transferred to a rubber hand after synchronous visual and tactile stimulation. Perceived body ownership and self–other relation are foundational for development of self-awareness, imitation, and empathy, which are all affected in autism spectrum disorders (ASD). We examined the rubber hand illusion in children with and without ASD. Children with ASD were initially less susceptible to the illusion than the comparison group, yet showe...

  11. Impact of verbal, braille text, and tactile oral hygiene awareness instructions on oral health status of visually impaired children

    OpenAIRE

    P Brahmanna Chowdary; K S Uloopi; Vinay, C.; V Veerabhadra Rao; Chandrasekhar Rayala

    2016-01-01

    Background: Visually impaired children face limitations in interacting with the environment, as they cannot see the facial expression of parents, teachers and cannot perceive social behavior. These children are challenged every day in learning basic life skills and maintenance of oral hygiene being one among them. Aim: To evaluate the impact of verbal, braille text, and tactile oral hygiene awareness instructions on oral health status of visually impaired children. Materials and Methods: One ...

  12. Capacitive Tactile Sensor Based on Dielectric Oil Displacement out of a Parylene Dome into Surrounding Channels

    Directory of Open Access Journals (Sweden)

    Seiji Aoyagi

    2012-03-01

    Full Text Available We propose a concept of a flexible sensor array using a novel capacitive force sensor not having a vulnerable electrode on the force applied site. It has a polymer domed structure inside which silicone oil is contained. When the force is applied, the oil is pushed into the surrounding thin channels, where the change in capacitance due to the inflowing dielectric oil is measured between two electrodes on the top and bottom surfaces of the channel. Since the channel does not have a directly applied external force to it, the electrodes do not suffer from damage problems. The change in capacitance was simulated using a simplified flow model. The first trial device of the sensing element has been fabricated. A sensitivity of 0.05 pF/gf was achieved.

  13. Perceptual Learning With Tactile Stimuli in Rats: Changes in the Processing of a Dimension

    Science.gov (United States)

    2016-01-01

    Four experiments with male rats investigated perceptual learning involving a tactile dimension (A, B, C, D, E), where A denotes 1 end of the continuum (e.g., a rough floor) and E the other (e.g., a smooth floor). In Experiment 1, rats given preexposure to A and E learned an appetitive discrimination between them more readily than those not given preexposure. Experiment 2a showed that rats preexposed to B and D acquired a discrimination between A and E more readily than those preexposed to A and E; and in Experiment 2b the same preexposure treatments had no effect on the acquisition of a discrimination between B and D. In Experiments 3a and 3b, rats given preexposure to C learned a discrimination between A and E more readily than those not given preexposure. Experiment 4 demonstrated that preexposure to a texture (e.g., B) that was adjacent to the to-be-discriminated textures (e.g., C and E) facilitated a discrimination between them relative to preexposure to their midpoint (D). These novel perceptual learning effects are interpreted as reflecting a redistribution of processing between the notional elements of the texture dimension. PMID:27379718

  14. Subject-level differences in reported locations of cutaneous tactile and nociceptive stimuli

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    Peter Steenbergen

    2012-11-01

    Full Text Available Recent theoretical advances on the topic of body representations have raised the question whether spatial perception of touch and nociception involve the same representations. Various authors have established that subjective localizations of touch and nociception are displaced in a systematic manner. The relation between veridical stimulus locations and localizations can be described in the form of a perceptual map; these maps differ between subjects. Recently, evidence was found for a common set of body representations to underlie spatial perception of touch and slow and fast pain, which receive information from modality specific primary representations. There are neurophysiological clues that the various cutaneous senses may not share the same primary representation. If this is the case, then differences in primary representations between touch and nociception may cause subject-dependent differences in perceptual maps of these modalities. We studied localization of tactile and nociceptive sensations on the forearm using electrocutaneous stimulation. The perceptual maps of these modalities differed at the group level. When assessed for individual subjects, the differences localization varied in nature between subjects. The agreement of perceptual maps of the two modalities was moderate. These findings are consistent with a common internal body representation underlying spatial perception of touch and nociception. The subject level differences suggest that in addition to these representations other aspects, possibly differences in primary representation and/or the influence of stimulus parameters, lead to differences in perceptual maps in individuals.

  15. Construction of an Evaluating System of Tactile Walking Surface Indicators for Persons with Vision Impairments

    Science.gov (United States)

    Sueda, Osamu; Fujisawa, Shoichiro; Xin, Wang

    An experiment to evaluate a tactile walking surface indicator for visually impaired persons was usually carried out in the outdoor environment, and the weather and the seasons affected on the schedule and the result. We constructed the evaluation system within the building so we could conduct walking experiments that were unaffected by the weather regardless of the four seasons. The subjects of this system were not only a visually impaired person and a sighted deaf person but also general person. The laboratory provided a soundproof and shaded structure consisting of the walls and the ceiling. External sound and light were blocked. The hue could be adjusted by three-color fluorescent lamps, and the light could be adjusted from daytime brightness to a dim moon light. Research into the walking of visually impaired persons at nighttime is a pressing problem as the barrier-free transportation law has been enacted in Japan. An international standard has been discussed, and a scientific basis for that standard is now required.

  16. Dissociating the neural correlates of tactile temporal order and simultaneity judgements

    Science.gov (United States)

    Miyazaki, Makoto; Kadota, Hiroshi; Matsuzaki, Kozue S.; Takeuchi, Shigeki; Sekiguchi, Hirofumi; Aoyama, Takuo; Kochiyama, Takanori

    2016-01-01

    Perceiving temporal relationships between sensory events is a key process for recognising dynamic environments. Temporal order judgement (TOJ) and simultaneity judgement (SJ) are used for probing this perceptual process. TOJ and SJ exhibit identical psychometric parameters. However, there is accumulating psychophysical evidence that distinguishes TOJ from SJ. Some studies have proposed that the perceptual processes for SJ (e.g., detecting successive/simultaneity) are also included in TOJ, whereas TOJ requires more processes (e.g., determination of the temporal order). Other studies have proposed two independent processes for TOJ and SJ. To identify differences in the neural activity associated with TOJ versus SJ, we performed functional magnetic resonance imaging of participants during TOJ and SJ with identical tactile stimuli. TOJ-specific activity was observed in multiple regions (e.g., left ventral and bilateral dorsal premotor cortices and left posterior parietal cortex) that overlap the general temporal prediction network for perception and motor systems. SJ-specific activation was observed only in the posterior insular cortex. Our results suggest that TOJ requires more processes than SJ and that both TOJ and SJ implement specific process components. The neural differences between TOJ and SJ thus combine features described in previous psychophysical hypotheses that proposed different mechanisms. PMID:27064734

  17. Prestimulus Alpha Power Influences Tactile Temporal Perceptual Discrimination and Confidence in Decisions.

    Science.gov (United States)

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2016-03-01

    Recent studies have demonstrated that prestimulus alpha-band activity substantially influences perception of near-threshold stimuli. Here, we studied the influence of prestimulus alpha power fluctuations on temporal perceptual discrimination of suprathreshold tactile stimuli and subjects' confidence regarding their perceptual decisions. We investigated how prestimulus alpha-band power influences poststimulus decision-making variables. We presented electrical stimuli with different stimulus onset asynchronies (SOAs) to human subjects, and determined the SOA for which temporal perceptual discrimination varied on a trial-by-trial basis between perceiving 1 or 2 stimuli, prior to recording brain activity with magnetoencephalography. We found that low prestimulus alpha power in contralateral somatosensory and occipital areas predicts the veridical temporal perceptual discrimination of 2 stimuli. Additionally, prestimulus alpha power was negatively correlated with confidence ratings in correctly perceived trials, but positively correlated for incorrectly perceived trials. Finally, poststimulus event-related fields (ERFs) were modulated by prestimulus alpha power and reflect the result of a decisional process rather than physical stimulus parameters around ∼150 ms. These findings provide new insights into the link between spontaneous prestimulus alpha power fluctuations, temporal perceptual discrimination, decision making, and decisional confidence. The results suggest that prestimulus alpha power modulates perception and decisions on a continuous scale, as reflected in confidence ratings. PMID:25331603

  18. A Tactile Sensor Using Piezoresistive Beams for Detection of the Coefficient of Static Friction

    Science.gov (United States)

    Okatani, Taiyu; Takahashi, Hidetoshi; Noda, Kentaro; Takahata, Tomoyuki; Matsumoto, Kiyoshi; Shimoyama, Isao

    2016-01-01

    This paper reports on a tactile sensor using piezoresistive beams for detection of the coefficient of static friction merely by pressing the sensor against an object. The sensor chip is composed of three pairs of piezoresistive beams arranged in parallel and embedded in an elastomer; this sensor is able to measure the vertical and lateral strains of the elastomer. The coefficient of static friction is estimated from the ratio of the fractional resistance changes corresponding to the sensing elements of vertical and lateral strains when the sensor is in contact with an object surface. We applied a normal force on the sensor surface through objects with coefficients of static friction ranging from 0.2 to 1.1. The fractional resistance changes corresponding to vertical and lateral strains were proportional to the applied force. Furthermore, the relationship between these responses changed according to the coefficients of static friction. The experimental result indicated the proposed sensor could determine the coefficient of static friction before a global slip occurs. PMID:27213374

  19. Perceptual learning with tactile stimuli in rats: Changes in the processing of a dimension.

    Science.gov (United States)

    Montuori, Luke M; Honey, R C

    2016-07-01

    Four experiments with male rats investigated perceptual learning involving a tactile dimension (A, B, C, D, E), where A denotes 1 end of the continuum (e.g., a rough floor) and E the other (e.g., a smooth floor). In Experiment 1, rats given preexposure to A and E learned an appetitive discrimination between them more readily than those not given preexposure. Experiment 2a showed that rats preexposed to B and D acquired a discrimination between A and E more readily than those preexposed to A and E; and in Experiment 2b the same preexposure treatments had no effect on the acquisition of a discrimination between B and D. In Experiments 3a and 3b, rats given preexposure to C learned a discrimination between A and E more readily than those not given preexposure. Experiment 4 demonstrated that preexposure to a texture (e.g., B) that was adjacent to the to-be-discriminated textures (e.g., C and E) facilitated a discrimination between them relative to preexposure to their midpoint (D). These novel perceptual learning effects are interpreted as reflecting a redistribution of processing between the notional elements of the texture dimension. (PsycINFO Database Record PMID:27379718

  20. Investigating the Role of Auditory and Tactile Modalities in Violin Quality Evaluation

    Science.gov (United States)

    Wollman, Indiana; Fritz, Claudia; Poitevineau, Jacques; McAdams, Stephen

    2014-01-01

    The role of auditory and tactile modalities involved in violin playing and evaluation was investigated in an experiment employing a blind violin evaluation task under different conditions: i) normal playing conditions, ii) playing with auditory masking, and iii) playing with vibrotactile masking. Under each condition, 20 violinists evaluated five violins according to criteria related to violin playing and sound characteristics and rated their overall quality and relative preference. Results show that both auditory and vibrotactile feedback are important in the violinists’ evaluations but that their relative importance depends on the violinist, the violin and the type of evaluation (different criteria ratings or preference). In this way, the overall quality ratings were found to be accurately predicted by the rating criteria, which also proved to be perceptually relevant to violinists, but were poorly correlated with the preference ratings; this suggests that the two types of ratings (overall quality vs preference) may stem from different decision-making strategies. Furthermore, the experimental design confirmed that violinists agree more on the importance of criteria in their overall evaluation than on their actual ratings for different violins. In particular, greater agreement was found on the importance of criteria related to the sound of the violin. Nevertheless, this study reveals that there are fundamental differences in the way players interpret and evaluate each criterion, which may explain why correlating physical properties with perceptual properties has been challenging so far in the field of musical acoustics. PMID:25474036

  1. Talking to the senses: Modulation of tactile extinction through hypnotic suggestion

    Directory of Open Access Journals (Sweden)

    Angelo eMaravita

    2012-07-01

    Full Text Available Brain damage can significantly impair the processing of sensory events. In particular, patients affected by extinction to double bilateral stimulations, show reduced awareness of stimuli delivered in the space contralateral to the brain lesion, when these are presented in competition with ipsilesional ones. The present work shows that hypnotic suggestion can temporarily improve tactile extinction. Patient EB showed an improved detection of contralesional targets after a single 20-minute hypnosis session, during which specific suggestions were delivered with the aim of increasing her insight into somatosensory perception on both sides of the body. Simple overt attention orienting towards the contralesional side, or a hypnotic induction procedure not accompanied by specifically aimed suggestions, were not effective in modulating extinction. The present result is the first systematic evidence that hypnosis can temporarily improve a neuropsychological condition, namely extinction, and may open the way for the use of this technique as a fruitful rehabilitative tool for brain-damaged patients affected by neuropsychological deficits.

  2. Definition of Tactile Interactions for a Multi-Criteria Selection in a Virtual World

    Directory of Open Access Journals (Sweden)

    Robin Vivian

    2014-12-01

    Full Text Available Tablets, smartphones are becoming increasingly common and interfaces are predominantly tactile and often multi-touch. More and more schools are testing them with their pupils in the hope of bringing pedagogic benefits. With this new type of devices, new interactions become possible. A lot of studies have been done on the manipulation of 3D objects with 2D input devices but we are just at the beginning of studies that made a link between needs of pedagogy and possibilities of these new types of interactions. FINGERS© is an application for learning spatial geometry. It’s written for pupils from 9 to 12 years old. Interactions have been designed with teachers. Some interactions are specifics for 3D geometry (3 DOF translations, rotations, nets, combinations of cubes, etc and someone are general like designation or multi-selection. A lot of grammars of gesture propose a set of interactions to select an object or a group of objects. Multi-taps or lasso around an area are commonly adopted interactions. Performing geometry exercises needs imaging another interactions. For example how selecting all Cubes, how selecting all green objects. The real question is how introduce a parameter in selection. After presenting the limits of current solutions, this communication presents the solutions developed in FINGERS©. We explain how they allow a “parameterized” selection.

  3. A Tactile Sensor Using Piezoresistive Beams for Detection of the Coefficient of Static Friction.

    Science.gov (United States)

    Okatani, Taiyu; Takahashi, Hidetoshi; Noda, Kentaro; Takahata, Tomoyuki; Matsumoto, Kiyoshi; Shimoyama, Isao

    2016-01-01

    This paper reports on a tactile sensor using piezoresistive beams for detection of the coefficient of static friction merely by pressing the sensor against an object. The sensor chip is composed of three pairs of piezoresistive beams arranged in parallel and embedded in an elastomer; this sensor is able to measure the vertical and lateral strains of the elastomer. The coefficient of static friction is estimated from the ratio of the fractional resistance changes corresponding to the sensing elements of vertical and lateral strains when the sensor is in contact with an object surface. We applied a normal force on the sensor surface through objects with coefficients of static friction ranging from 0.2 to 1.1. The fractional resistance changes corresponding to vertical and lateral strains were proportional to the applied force. Furthermore, the relationship between these responses changed according to the coefficients of static friction. The experimental result indicated the proposed sensor could determine the coefficient of static friction before a global slip occurs. PMID:27213374

  4. Evaluation of headache intensity in migrainous patients with visual handicap through the tactile analogical scale (TAS

    Directory of Open Access Journals (Sweden)

    Piovesan Elcio Juliato

    2001-01-01

    Full Text Available The tactile analogue scale (TAS was elaborated to be used in blind subjects or those who can not use the vision during their crises. The objective of this study was to characterize, from TAS, the architecture of migraine attacks in subjects with visual disability. For that, 11 migrainous with visual disturb (MVD subjects were studied and 22 migrainous subjects with no visual disability as a control group. All patients fulfilled the criteria for migraine and the patients of the group studied showed visual acuteness less than 20/200. To evaluate the results, the patients of the group MVD were subdivide within two groups, according to their visual acuteness: subgroup A subjects with subnormal vision and subgroup B amaurotic ones. In subgroup A measurement 46 attacks with average of the migraine attacks of the 56.50 mm, in the subgroup B 45 attacks with average of the 59.58mm and in the control group 92 attacks with average of the 49.88mm. When subgroup B and control group were compared there was a significant statistic difference (p=0.022. Through these outcomes we can observe that the migrainous subjects with no visual afference show a higher pain intensity during the migraine crises comparing to those subjects with no visual handicap. The study suggests that, as in other forms of sensibility, the total visual loss can also interfere in the nociceptive control of the pain during the migraine attacks.

  5. Vertical distribution, feeding and vulnerability to tactile predation in Metridia longa (Copepoda, Calanoida)

    KAUST Repository

    Vestheim, Hege

    2013-12-01

    We assessed the vertical distribution and feeding of the calanoid copepod Metridia longa in the Oslofjord, Norway during winter and spring 2006. Adult females of Metridia longa inhabited the whole 200 m deep-water column. Their distribution was shallower at night than during the day. Enumeration of egested faecal pellets suggested that feeding activity was greater at night than during the day and that more pellets were produced by individuals collected at shallow depths vs. by individuals found deeper. There was no pronounced difference between months in feeding activity. Although the hypothesis is that they prey on Calanus eggs and nauplii, scanning of Metridia faecal pellets by PCR using Calanus-specific primers did not confirm the presence of any Calanus prey DNA. Most pellets had a greenish colour, implying herbivorous feeding. Feeding is related to swimming, and the actively swimming Metridia would presumably be vulnerable to tactile invertebrate predators. However, predation experiments where the carnivorous copepod Pareuchaeta norvegica was offered similar-sized Metridia and Calanus proved that Pareuchaeta consumed the less-active Calanus, but not the Metridia. © 2013 Copyright Taylor and Francis Group, LLC.

  6. Tactile stimulation effects on hippocampal neurogenesis and spatial learning and memory in prenatally stressed rats.

    Science.gov (United States)

    de Los Angeles, Guerrero Aguilera María; Del Carmen, Rubio Osornio María; Wendy, Portillo Martínez; Socorro, Retana-Márquez

    2016-06-01

    Neurogenesis in the dentate gyrus (DG) of the hippocampus is increased by spatial learning and postnatal stimulation. Conversely, prenatal stress (PS) produces a decrease in the proliferation of hippocampal granular cells. This work evaluated the effect of postnatal tactile stimulation (PTS), when applied from birth to adulthood, on cognitive performance and hippocampal neurogenesis (survival and differentiation) in PS female and male rats. The response of the adrenal axis to training in the Morris water maze (MWM) was also analyzed. PS was provided during gestational days 15 through 21. Hippocampal neurogenesis and cognitive performance in the MWM were assessed at an age of three months. Results showed that escape latencies of both female and male PS rats were longer compared to those of their controls (CON). DG cell survival increased in the PS female rats. Corticosterone concentrations were significantly higher in the male and female PS rats after MWM training. PTS improved escape latencies and increased the number of new neurons in the DG of PS animals, and their corticosterone concentrations were similar to those in CON. In CON, PTS diminished DG cell survival but increased differentiation and reduces latency in the MWM. These results show that long-term PTS in PS animals might prevent learning deficits in adults through increase in the number of DG new cells and decrease of the reactivity of the adrenal axis to MWM training. PMID:26993794

  7. Sleep dissolves illusion: sleep withstands learning of visuo-tactile-proprioceptive integration induced by repeated days of rubber hand illusion training.

    Directory of Open Access Journals (Sweden)

    Motoyasu Honma

    Full Text Available Multisensory integration is a key factor in establishing bodily self-consciousness and in adapting humans to novel environments. The rubber hand illusion paradigm, in which humans can immediately perceive illusory ownership to an artificial hand, is a traditional technique for investigating multisensory integration and the feeling of illusory ownership. However, the long-term learning properties of the rubber hand illusion have not been previously investigated. Moreover, although sleep contributes to various aspects of cognition, including learning and memory, its influence on illusory learning of the artificial hand has not yet been assessed. We determined the effects of daily repetitive training and sleep on learning visuo-tactile-proprioceptive sensory integration and illusory ownership in healthy adult participants by using the traditional rubber hand illusion paradigm. Subjective ownership of the rubber hand, proprioceptive drift, and galvanic skin response were measured to assess learning indexes. Subjective ownership was maintained and proprioceptive drift increased with daily training. Proprioceptive drift, but not subjective ownership, was significantly attenuated after sleep. A significantly greater reduction in galvanic skin response was observed after wakefulness compared to after sleep. Our results suggest that although repetitive rubber hand illusion training facilitates multisensory integration and physiological habituation of a multisensory incongruent environment, sleep corrects illusional integration and habituation based on experiences in a multisensory incongruent environment. These findings may increase our understanding of adaptive neural processes to novel environments, specifically, bodily self-consciousness and sleep-dependent neuroplasticity.

  8. SYNTHESIZABLE AND PROTOTYPIC VISUAL-TACTILE SYSTEM-IN FPGA: AN ALTERNATIVE TO ANALYSIS AND IMPROVEMENT OF THE VOICE QUALITY FOR THE HEARING IMPAIRED PEOPLE

    Directory of Open Access Journals (Sweden)

    Rodrigo Leone Alves

    2016-04-01

    Full Text Available Oral communication comprises one of the most important forms of social interaction. The process of learning the spoken language depends on the hearing, therefore, the total or partial loss of hearing sensitivity hinders such aspect. Digital signal processing techniques with non-invasive character are used for diagnosis, support and improvement of the voice quality of the deaf. Thus, the present study aims to propose and develop a system of analysis and correction of vocal disorders by means of visual and tactile feedback with module implemented in programmable device type FPGA (Field Programmable Gate Array. The results point to the potential of a proposed intervention as a helper for sensory substitution, being based on the monitoring and control of speech, in order to allow for the assessment and remediation by means of an electronic resource, allowing deaf individuals to obtain a support for learning the spoken language. The possibilities for improvements in communication skills observed in this study are dependent on the capability of the device together with the speech therapist, integrating therapies with the support of the family, the time and the motivation of the user, factors that cooperate for the success of this approach.

  9. A scalable, high resolution strain sensing matrix suitable for tactile transduction.

    Science.gov (United States)

    Scibelli, Anthony E; Krans, Jacob L

    2016-02-01

    The integration of tactile information, such as contact area, displacement magnitude, velocity, and acceleration, is paramount to the optimization of robotics in human-centric environments. Cost effective embeddable sensors with scalable receptive field size and strain sensitivity are not readily commercially available and would benefit investigations of in situ tissue mechanics. We describe the design and performance of a scalable sensor matrix that transduces fine parameters of strain and is made of combinable "modules". The sensors transduce static and dynamic strains of both uniaxial and multi-dimensional nature. Modules consist of three silicon wafers placed on top of and three on the bottom of a hexagonal collar, wafers are thus positioned 120° to one another to facilitate force vector extrapolation. Analog signals from each sensor can be easily compared to neighboring sensor output to determine mechanical phenomena such as slip or shear. The smallest of our prototype multiunit matrices consisted of seven hexes in a honeycomb orientation of 4.1mm diameter (containing 42 silicon gauges). Unamplified, unshielded output from this embodiment (3 Vexc button cell) yielded 1 mV from 5 μm displacement. Transduction linearity was high (R>0.99 nearest displacement) and exhibited nominal hysteresis. Modules may be placed upon or embedded into a multitude of materials and the size of individual hexagons may be scaled for favorable stiffness to strain ratio and to scale receptive field. Given the scalability of matrix size and resolution, we believe the sensor matrices could benefit the fields of prosthetics, robotics, and physiologic investigation of tissue mechanics. PMID:26710986

  10. A system for inducing concurrent tactile and nociceptive sensations at the same site using electrocutaneous stimulation.

    Science.gov (United States)

    Steenbergen, Peter; Buitenweg, Jan R; Trojan, Jörg; van der Heide, Esther M; van den Heuvel, Teun; Flor, Herta; Veltink, Peter H

    2012-12-01

    Studies of the interaction between mechanoception and nociception would benefit from a method for stimulation of both modalities at the same location. For this purpose, we developed an electrical stimulation device. Using two different electrode geometries, discs and needles, the device is capable of inducing two distinct stimulus qualities, dull and sharp, at the same site on hairy skin. The perceived strength of the stimuli can be varied by applying stimulus pulse trains of different lengths. We assessed the perceived stimulus qualities and intensities of the two electrode geometries at two levels of physical stimulus intensity. In a first series of experiments, ten subjects participated in two experimental sessions. The subjects reported the perceived quality and intensity of four different stimulus classes on visual analogue scales (VASs). In a second series, we added a procedure in which subjects assigned descriptive labels to the stimuli. We assessed the reproducibility of the VAS scores by calculating intraclass correlation coefficients. The results showed that subjects perceived stimuli delivered through the disc electrodes as dull and those delivered through the needles as sharp. Increasing the pulse train length increased the perceived stimulus intensities without decreasing the difference in quality between the electrode types. The intraclass correlation coefficients for the VAS scores ranged from .75 to .95. The labels that were assigned for the two electrode geometries corresponded to the descriptors for nociception and touch reported by other researchers. We concluded that our device is capable of reliably inducing tactile and nociceptive sensations of controllable intensity at the same skin site. PMID:22806702

  11. Spontaneous Chronic Pain After Experimental Thoracotomy Revealed by Conditioned Place Preference: Morphine Differentiates Tactile Evoked Pain From Spontaneous Pain.

    Science.gov (United States)

    Hung, Ching-Hsia; Wang, Jeffrey Chi-Fei; Strichartz, Gary R

    2015-09-01

    Chronic pain after surgery limits social activity, interferes with work, and causes emotional suffering. A major component of such pain is reported as resting or spontaneous pain with no apparent external stimulus. Although experimental animal models can simulate the stimulus-evoked chronic pain that occurs after surgery, there have been no studies of spontaneous chronic pain in such models. Here the conditioned place preference (CPP) paradigm was used to reveal resting pain after experimental thoracotomy. Male Sprague Dawley rats received a thoracotomy with 1-hour rib retraction, resulting in evoked tactile hypersensitivity, previously shown to last for at least 9 weeks. Intraperitoneal injections of morphine (2.5 mg/kg) or gabapentin (40 mg/kg) gave equivalent 2- to 3-hour-long relief of tactile hypersensitivity when tested 12 to 14 days postoperatively. In separate experiments, single trial CPP was conducted 1 week before thoracotomy and then 12 days (gabapentin) or 14 days (morphine) after surgery, followed the next day by 1 conditioning session with morphine or gabapentin, both versus saline. The gabapentin-conditioned but not the morphine-conditioned rats showed a significant preference for the analgesia-paired chamber, despite the equivalent effect of the 2 agents in relieving tactile allodynia. These results show that experimental thoracotomy in rats causes spontaneous pain and that some analgesics, such as morphine, that reduce evoked pain do not also relieve resting pain, suggesting that pathophysiological mechanisms differ between these 2 aspects of long-term postoperative pain. Perspective: Spontaneous pain, a hallmark of chronic postoperative pain, is demonstrated here in a rat model of experimental postthoracotomy pain, further validating the use of this model for the development of analgesics to treat such symptoms. Although stimulus-evoked pain was sensitive to systemic morphine, spontaneous pain was not, suggesting different mechanistic

  12. Psychological Basis of the Relationship Between the Rorschach Texture Response and Adult Attachment: The Mediational Role of the Accessibility of Tactile Knowledge.

    Science.gov (United States)

    Iwasa, Kazunori; Ogawa, Toshiki

    2016-01-01

    This study clarifies the psychological basis for the linkage between adult attachment and the texture response on the Rorschach by examining the mediational role of the accessibility of tactile knowledge. Japanese undergraduate students (n = 35) completed the Rorschach Inkblot Method, the Experiences in Close Relationship Scale for General Objects (Nakao & Kato, 2004) and a lexical decision task designed to measure the accessibility of tactile knowledge. A mediation analysis revealed that the accessibility of tactile knowledge partially mediates the association between attachment anxiety and the texture response. These results suggest that our hypothetical model focusing on the response process provides a possible explanation of the relationship between the texture response and adult attachment. PMID:26569020

  13. A Novel Two-Wire Fast Readout Approach for Suppressing Cable Crosstalk in a Tactile Resistive Sensor Array

    Science.gov (United States)

    Wu, Jianfeng; Wang, Yu; Li, Jianqing; Song, Aiguo

    2016-01-01

    For suppressing the crosstalk problem due to wire resistances and contacted resistances of the long flexible cables in tactile sensing systems, we present a novel two-wire fast readout approach for the two-dimensional resistive sensor array in shared row-column fashion. In the approach, two wires are used for every driving electrode and every sampling electrode in the resistive sensor array. The approach with a high readout rate, though it requires a large number of wires and many sampling channels, solves the cable crosstalk problem. We also verified the approach’s performance with Multisim simulations and actual experiments. PMID:27213373

  14. Learning touch preferences with a tactile robot using dopamine modulated STDP in a model of insular cortex

    OpenAIRE

    Ting-Shuo eChou; Bucci, Liam D.; Jeffrey L. Krichmar

    2015-01-01

    Neurorobots enable researchers to study how behaviors are produced by neural mechanisms in an uncertain, noisy, real-world environment. To investigate how the somatosensory system processes noisy, real-world touch inputs, we introduce a neurorobot called CARL-SJR, which has a full-body tactile sensory area. The design of CARL-SJR is such that it encourages people to communicate with it through gentle touch. CARL-SJR provides feedback to users by displaying bright colors on its surface. In the...

  15. TOOTEKO: A CASE STUDY OF AUGMENTED REALITY FOR AN ACCESSIBLE CULTURAL HERITAGE. DIGITIZATION, 3D PRINTING AND SENSORS FOR AN AUDIO-TACTILE EXPERIENCE

    OpenAIRE

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

    2015-01-01

    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...

  16. Spinal fMRI during proprioceptive and tactile tasks in healthy subjects: activity detected using cross-correlation, general linear model and independent component analysis

    International Nuclear Information System (INIS)

    Functional MRI (fMRI) of the spinal cord is able to provide maps of neuronal activity. Spinal fMRI data have been analyzed in previous studies by calculating the cross-correlation (CC) between the stimulus and the time course of every voxel and, more recently, by using the general linear model (GLM). The aim of this study was to compare three different approaches (CC analysis, GLM and independent component analysis (ICA)) for analyzing fMRI scans of the cervical spinal cord. We analyzed spinal fMRI data from healthy subjects during a proprioceptive and a tactile stimulation by using two model-based approaches, i.e., CC analysis between the stimulus shape and the time course of every voxel, and the GLM. Moreover, we applied independent component analysis, a model-free approach which decomposes the data in a set of source signals. All methods were able to detect cervical cord areas of activity corresponding to the expected regions of neuronal activations. Model-based approaches (CC and GLM) revealed similar patterns of activity. ICA could identify a component correlated to fMRI stimulation, although with a lower statistical threshold than model-based approaches, and many components, consistent across subjects, which are likely to be secondary to noise present in the data. Model-based approaches seem to be more robust for estimating task-related activity, whereas ICA seems to be useful for eliminating noise components from the data. Combined use of ICA and GLM might improve the reliability of spinal fMRI results. (orig.)

  17. A Sensitivity Enhanced MWCNT/PDMS Tactile Sensor Using Micropillars and Low Energy Ar+ Ion Beam Treatment

    Directory of Open Access Journals (Sweden)

    Syed Azkar Ul Hasan

    2016-01-01

    Full Text Available High sensitive flexible and wearable devices which can detect delicate touches have attracted considerable attentions from researchers for various promising applications. This research was aimed at enhancing the sensitivity of a MWCNT/PDMS piezoresistive tactile sensor through modification of its surface texture in the form of micropillars on MWCNT/PDMS film and subsequent low energy Ar+ ion beam treatment of the micropillars. The introduction of straight micropillars on the MWCNT/PDMS surface increased the sensitivity under gentle touch. Low energy ion beam treatment was performed to induce a stiff layer on the exposed surface of the micropillar structured MWCNT/PDMS film. The low energy ion bombardment stabilized the electrical properties of the MWCNT/PDMS surface and tuned the curvature of micropillars according to the treatment conditions. The straight micropillars which were treated by Ar+ ion with an incident angle of 0° demonstrated the enhanced sensitivity under normal pressure and the curved micropillars which were treated with Ar+ ion with an incident angle of 60° differentiated the direction of an applied shear pressure. The ion beam treatment on micropillar structured MWCNT/PDMS tactile sensors can thus be applied to reliable sensing under gentle touch with directional discrimination.

  18. Bilateral mechanical and thermal hyperalgesia and tactile allodynia after chronic compression of dorsal root ganglion in mice.

    Science.gov (United States)

    Chen, Rong-Gui; Kong, Wei-Wei; Ge, Da-Long; Luo, Ceng; Hu, San-Jue

    2011-08-01

    OBJECTIVE Low back pain is one of the most inextricable problems encountered in clinics. Animal models that imitate symptoms in humans are valuable tools for investigating low back pain mechanisms and the possible therapeutic applications. With the development of genetic technology in pain field, the possibility of mutating specific genes in mice has provided a potent tool for investigating the specific mechanisms of pain. The aim of the present study was to develop a mouse model of chronic compression of dorsal root ganglion (CCD), in which gene mutation can be applied to facilitate the studies of chronic pain. METHODS Chronic compression of L4 and L5 dorsal root ganglia was conducted in mice by inserting fine stainless steel rods into the intervertebral foramina, one at L4 and the other at L5. Mechanical allodynia and thermal hyperalgesia were examined with von Frey filaments and radiating heat stimulator, respectively. RESULTS The CCD mice displayed dramatic mechanical and thermal hyperalgesia as well as tactile allodynia in the hindpaw ipsilateral to CCD. In addition, this mechanical and thermal hyperalgesia as well as tactile allodynia was also found to spread to the contralateral hindpaw. CONCLUSION This model, combined with the possible genetic modification, will strengthen our knowledge of the underlying mechanisms of low back pain. It also favors the development of new treatment strategies for pain and hyperalgesia after spinal injury and other disorders which affect the dorsal root ganglion in humans. PMID:21788994

  19. The role of vestibular and support-tactile-proprioceptive inputs in visual-manual tracking

    Science.gov (United States)

    Kornilova, Ludmila; Naumov, Ivan; Glukhikh, Dmitriy; Khabarova, Ekaterina; Pavlova, Aleksandra; Ekimovskiy, Georgiy; Sagalovitch, Viktor; Smirnov, Yuriy; Kozlovskaya, Inesa

    Sensorimotor disorders in weightlessness are caused by changes of functioning of gravity-dependent systems, first of all - vestibular and support. The question arises, what’s the role and the specific contribution of the support afferentation in the development of observed disorders. To determine the role and effects of vestibular, support, tactile and proprioceptive afferentation on characteristics of visual-manual tracking (VMT) we conducted a comparative analysis of the data obtained after prolonged spaceflight and in a model of weightlessness - horizontal “dry” immersion. Altogether we examined 16 Russian cosmonauts before and after prolonged spaceflights (129-215 days) and 30 subjects who stayed in immersion bath for 5-7 days to evaluate the state of the vestibular function (VF) using videooculography and characteristics of the visual-manual tracking (VMT) using electrooculography & joystick with biological visual feedback. Evaluation of the VF has shown that both after immersion and after prolonged spaceflight there were significant decrease of the static torsional otolith-cervical-ocular reflex (OCOR) and simultaneous significant increase of the dynamic vestibular-cervical-ocular reactions (VCOR) with a revealed negative correlation between parameters of the otoliths and canals reactions, as well as significant changes in accuracy of perception of the subjective visual vertical which correlated with changes in OCOR. Analyze of the VMT has shown that significant disorders of the visual tracking (VT) occurred from the beginning of the immersion up to 3-4 day after while in cosmonauts similar but much more pronounced oculomotor disorders and significant changes from the baseline were observed up to R+9 day postflight. Significant changes of the manual tracking (MT) were revealed only for gain and occurred on 1 and 3 days in immersion while after spaceflight such changes were observed up to R+5 day postflight. We found correlation between characteristics

  20. Immediate effects of thermal-tactile stimulation on timing of swallow in idiopathic Parkinson's disease.

    LENUS (Irish Health Repository)

    Regan, Julie

    2012-02-01

    Oropharyngeal dysphagia frequently presents in people with idiopathic Parkinson\\'s disease (IPD). Clinical sequelae of dysphagia in this group include weight loss and aspiration pneumonia, the latter of which is the leading cause of hospital admissions and death in IPD. Thermal-tactile stimulation (TTS) is a sensory technique whereby stimulation is provided to the anterior faucial pillars to speed up the pharyngeal swallow. The effects of TTS on swallowing have not yet been investigated in IPD. The aim of this study was to investigate the immediate effects of TTS on the timing of swallow in a cohort of people with IPD and known oropharyngeal dysphagia. Thirteen participants with IPD and known dysphagia attended for videofluoroscopy during which standardised volumes of liquid barium and barium paste were administered preceding and immediately subsequent to TTS. The immediate effects of TTS on swallowing were examined using oral, pharyngeal, and total transit times and pharyngeal delay times as outcome measures. TTS significantly reduced median pharyngeal transit time on fluids (0.20 s, 95% CI = 0.12-0.28, p = 0.004) and on paste (0.3 s, 95% CI = 0.08-0.66, p = 0.01). Median total transit time was also reduced on fluids (0.48 s, 95% CI = 0.00-1.17, p = 0.049) and on paste (0.52 s, 95% CI = 0.08-1.46, p = 0.033). Median pharyngeal delay time was reduced on fluids (0.20 s, 95% CI = 0.12-0.34, p = 0.002). TTS did not significantly alter median oral transit time on either fluid or paste consistency. TTS significantly reduced temporal measures of the pharyngeal phase of swallowing in the IPD population. Significant results may be attributed to the role of sensory stimulation in improving motor function in IPD, with emphasis on the impaired glossopharyngeal and vagus nerves in this population. It is still unclear whether these findings will translate into a clinically beneficial effect.